[The short test with hydrochlorothiazide in differential diagnosis between primary normocalcemic and secondary hyperparathyroidism for inpatient treatment].

BACKGROUND: Differential diagnosis between the normocalcemic primary hyperparathyroidism (nPHPT) and secondary hyperparathyroidism (SHPT) due to hypercalciuria remains a challenge. AIM: The aim of this study was to investigate the capability of short test with hydrochlorothiazide for the differential diagnosis of nPHPT and SHPT. MATERIALS AND METHODS: A retrospective study was conducted with the participation of 28 patients who underwent a functional test with thiazide diuretics during hospitalization in the Department of parathyroid glands pathology and mineral disorders of the Endocrinology Research Centre, Russia. Parameters of mineral metabolism were evaluated before and 3-5 days after taking hydrochlorothiazide 50 mg/day. RESULTS: According to baseline and dynamic biochemical evaluation patients were divided into 3 groups. Group 1 (n=21) included patients with confirmed PHPT, who reached hypercalcemia accompanying with an elevated level of iPTH (n=19) or an increased level of iPTH accompanying with normocalcemia (n=2). In group 1, baseline Caadj. was 2.48 mmol/l [2.47; 2.52], iPTH 107.5 pg/ml [86.8; 133.0], after short test - 2.63 mmol/l [2.59; 2.66] and 102.1 pg/ml [95,7; 124,1]. Group 2 included only one who was diagnosed with SHPT, a normal value of iPTH with concomitant normocalcemia was achieved after 4 days of hydrochlorothiazide therapy (baseline Caadj. 2.35 mmol/l, iPTH 74.5 pg/ml vs at 2.27 mmol/l and 50.7 pg/ml respectively). Patients with doubtful results of the test entered in group 3 (n=6), they did not achieve significant changes in the calcium and iPTH levels, so it was recommended to continue the test on an outpatient basis (baseline Caadj. 2.39 mmol/l [2.33;2.45], iPTH 97.0 pg/ml [83.1;117.0]); after short test - 2.47 mmol/l [2.42; 2.48] and 91.3 pg/ml [86.9; 124.0] respectively). Groups with PHPT and SHPT and doubtful results significantly differed from each other in Caadj (р=0.003, U-test, Bonferroni correction Р0=0.006), but not in iPTH, daily calciuria, eGFR, and phosphorus. There were no significant differences in the incidence of classical complications of PHPT. CONCLUSION: The diagnosis of PHPT was confirmed in 21/28 patients 3-5 days after taking hydrochlorothiazide 50 mg/day. The obtained results are significant for the differential diagnosis in hospitalized patients with an unspecified genesis of hyperparathyroidism.

A new approach for the study of the morphological structure of microbal biofilms.

Microbial biofilms are heterogeneous, moving and constantly changing communities of microorganisms, often of various taxons. Approaches to study and assessment anti-biofilm drugs widely available today do not adequately assess their effects, while the results of studying the interaction of drugs with components of the film composition can provide them the right choice. The aim of investigation was to test a new method of morphological evaluation of biofilms. To form biofilms, we used an approach when the slide was placed at an angle of 30o-45o relatively to the Petri dish, and a suspension of test strains S. epidermidis in peptone broth was poured into the space between the Petri dish and the slide. A sterile cotton swab moistened with distilled water was placed next to the glass slide to create optimal humidity. The system was placed in a thermostat for 24 hours. The formed films were examined under a microscope using the DCM 310 video eyepiece and the Scope photo x86,3.1.312 program that allowed to conduct a complete morphometric study of the film: select layers, channels, cavities and make measurements, and then save the results on electronic media in jpg file format. Microscopy of the stained slides revealed that the biofilm has a layered structure. In each image obtained using a video eyepiece, it was possible to differentiate 4 layers. From the border of the two media to the inside: the fragmentation layer, the dense layer, the matrix substance layer, and the last one - the persistence layer. Channels of different diameters (from 10 to 24 microns) are observed across the entire thickness of the biofilm. Thus, used approach allows us to visualize and evaluate the structure of microbial biofilm, measure the thickness of layers and channel diameters. In addition, this method can be used to study the effect of antimicrobial drugs on bacterial films.

Control of accuracy in the Wang-Landau algorithm.

The Wang-Landau (WL) algorithm has been widely used for simulations in many areas of physics. Our analysis of the WL algorithm explains its properties and shows that the difference of the largest eigenvalue of the transition matrix in the energy space from unity can be used to control the accuracy of estimating the density of states. Analytic expressions for the matrix elements are given in the case of the one-dimensional Ising model. The proposed method is further confirmed by numerical results for the one-dimensional and two-dimensional Ising models and also the two-dimensional Potts model.

[A clinical Case-of Icenko-Cushing Syndrome in a Female Patient with Morbit Obesity after Bariatric Surgery].

The efficacy of morbid obesity therapy at present remains rather low. Bariatric surgery is one of the most efficient methods for the treatment. Safety, efficacy and favourable results of the surgery are provided only after thorough examination of the patients.

Cys377 residue in NqrF subunit confers Ag(+) sensitivity of Na+-translocating NADH:quinone oxidoreductase from Vibrio harveyi.

The Na(+)-translocating NADH:quinone oxidoreductase (Na(+)-NQR) is a component of the respiratory chain of various bacteria that generates a redox-driven transmembrane electrochemical Na(+) potential. The Na(+)-NQR activity is known to be specifically inhibited by low concentrations of silver ions. Replacement of the conserved Cys377 residue with alanine in the NqrF subunit of Na(+)-NQR from Vibrio harveyi resulted in resistance of the enzyme to Ag(+) and to other heavy metal ions. Analysis of the catalytic activity also showed that the rate of electron input into the mutant Na(+)-NQR decreased by about 14-fold in comparison to the wild type enzyme, whereas all other properties of (NqrF)C377A Na(+)-NQR including its stability remained unaffected.

Site-directed mutagenesis of conserved cysteine residues in NqrD and NqrE subunits of Na+-translocating NADH:quinone oxidoreductase.

Each of two hydrophobic subunits of Na+-translocating NADH:quinone oxidoreductase (NQR), NqrD and NqrE, contain a pair of strictly conserved cysteine residues within their transmembrane alpha-helices. Site-directed mutagenesis showed that substitutions of these residues in NQR of Vibrio harveyi blocked the Na+-dependent and 2-n-heptyl-4-hydroxyquinoline N-oxide-sensitive quinone reductase activity of the enzyme. However, these mutations did not affect the interaction of NQR with NADH and menadione. It was demonstrated that these conserved cysteine residues are necessary for the correct folding and/or the stability of the NQR complex. Mass and EPR spectroscopy showed that NQR from V. harveyi bears only a 2Fe-2S cluster as a metal-containing prosthetic group.

Proton transfer through the membrane-water interfaces in uncoupled mitochondria.

Increase in maximal respiration rate of uncoupled mitochondria in response to increase in concentration of non-penetrating buffer has been demonstrated. This phenomenon did not depend on chemical structure of uncouplers and composition of the non-penetrating buffer. Use of covalently attached pH probe, FITC, revealed that at low buffer concentration (3 mM) the H(+)-pump functioning results in local increase in proton concentration on the outer surface of the inner mitochondrial membranes. In other words, local H(+) gradient was generated. Increase in buffer concentration up to 20 mM caused sharp decrease in this gradient, which occurred in parallel to increase in the respiration rate. It is concluded that both effects described here may be attributed to the process of proton transfer through the interfaces of the mitochondrial membrane: the rate of respiratory H(+) pumps of uncoupled mitochondria under conditions of low buffer capacity of medium is limited by the stage of proton release from outer surface of the coupling membrane. The inhibition mechanism of respiration by high concentrations of uncouplers is also discussed.

Does chlamydia trachomatis influence manifestations of Lyme Arthritis?

Lyme arthritis, caused by the tick-borne spirochete Borrelia burgdorferi, produces typically intermittent episodes of arthritis of the larger joints, usually the knee joints. A number of patients, however, develop arthritis more closely resembling Reiter's syndrome, i.e., heel and ankle involvement. We studied the clinical features of ten patients who developed arthritis after a tick bite and who had shown erythema migrans and related it to the presence of evidence of Chlamydia trachomatis infection. Along with typical signs of Lyme arthritis we observed heel and ankle involvement. Chlamydia trachomatis was found in smears in 4 cases, whereas no patient had antichlamydial antibodies. However, evidence of Chlamydia trachomatis did not correlate with signs considered typical of Reiter's syndrome. Therefore, Lyme arthritis may have some arthritic manifestations resembling Reiter's syndrome, but this seems unrelated to the presence of Chlamydia trachomatis. Moreover, the arthritis is not associated with HLA-B27.

Interneuronal functional associations in the sensorimotor cortex of dogs.

The interneuronal functional associations were studied in two dogs with Nichrome semi-microelectrodes implanted into the deep layers of the motor and somatosensory regions of the cerebral cortex using the method of cross-correlation analysis. For this purpose the impulse activity of individual neurons was distinguished by form from the background multineuronal activity using the spike recognition technique. Values of a 0.5 and 1 msec-wide bin, and thereafter with a 1 msec step up to 40 msec, were used to plot the cross-interval histograms. The maximal analysis epoch was 2000 msec. The cross-interval associations were monotypal in character; they all presented fairly narrow extrema which were clearly distributed across three time ranges: short-latency associations up to 10 msec; associations with a medium latency up to 80 msec; and associations with late delays, greater than 80 msec. The fairly narrow peak of the association, especially in the case of associations with late delays, was a very difficult phenomenon to explain from the point of view of traditional theoretical perspectives. It is hypothesized that a mechanism exists in the cortex which is responsible for strictly synchronized and highly efficient synaptic transmission.

[The interneuronal functional connections in the sensorimotor cortex of dogs]. / Mezhneironnye funktsional'nye sviazi v sensomotornoi kore u sobak.

Multiunit activity of sensorimotor cortex was recorded from chronically implanted semi-microelectrodes in two dogs. Functional interneuronal connections between neuronal spike trains of 6-8 neurons selected from background multiunit activity were studied by the method of cross-correlation analysis. Bin widths 0.5, 1, 2, 3 and further up to 40 ms by step of 1 ms were used. The cross-interval connections were characterized by complete absence of the shared input (central symmetrical peaks) and signs of inhibitory interrelations. The temporal interrelations between selected neurons were characterized by unilateral and bilateral non-symmetrical excitatory connections--ultra-narrow peaks with short (1-10 ms), middle (10-80 ms) and long (80-2000 ms) delays. The existence of such ultra-narrow peaks contradicts "classical" conceptions on the character of cross-interval connections based on model experiments on simple nervous systems. We suppose that special mechanism of synchronization with high temporal accuracy exists in the cortex.

[Beam radiotherapy of malignant tumors using computer-assisted radiotherapy programs]. / Distantsionnaia luchevaia terapiia zlokachestvennykh opukholei s ispol'zovaniem optimizirovannykh na EBM programm oblucheniia.

The authors give a brief description a ROKUS-M + Altai-MT system, its software ASPECT-1, stages of radiotherapy design and implementation of optimized programs. They gave examples of optimum computerized design of irradiation in tumors of the nasopharynx, breast, female genitals, esophagus, lungs, bladder, and rectum. The paper is illustrated with charts of isodoses and distributions corresponding to optimized programs of irradiation.

[An improvement in the therapy of psoriasis at the Pyatigorsk health resort taking into account circadian biorhythms]. / Sovershenstvovanie terapii psoriaza na kurorte Piatigorsk s uchetom tsirkadnykh bioritmov.

A randomized study entering 560 psoriasis patients on balneotherapy at Pyatigorsk health resort showed that morning balneotherapy sessions were more efficient.

[The TDF (time-dose-fractionation) model in brachytherapy]. / Model' VDF pri korotkodistantsionnoi rentgenoterapii.

A method to determine TDF values by standard tables with account of RBE of low-energy x-radiation and a small area of irradiation fields was proposed. Corresponding formulas confirmed by the authors' clinical data, were developed. The authors outlined ways of using these data for assessment and design of courses of brachytherapy to minimize the risk of development of skin radiation damages.

[Application of the DMF model taking into account volume and area of irradiated tissue to the prognosis of radiation complications]. / Primenenie modeli VDF s uchetom ob"ema i ploshchadi obluchaemykh tkanei dlia prognozirovaniia luchevykh oslozhnenii.

Coefficients Kv and Ks for determination of the influence of a volume and area of irradiated tissues in the assessment of DMF factors were presented. The above coefficients were derived on the basis of calculations and a retrospective analysis of the authors' clinical data on radiation complications in the subcutaneous fatty tissue in teleradiotherapy of malignant tumors. The use of the coefficients will make it possible to predict with greater reliability the probability of radiation complications in designing radiation therapy.