[Features of the course of COVID-19 in patients with type 2 diabetes mellitus].

AIM: To identify the features of the course of COVID-19 in patients with type 2 diabetes mellitus (T2DM), depending on the intake of hypoglycemic therapy at the prehospital stage, in conjunction with the functional state of the kidneys. MATERIALS AND METHODS: A retrospective analysis of 291 case histories of patients with COVID-19 and T2DM hospitalized in the infection department of Semashko Regional Clinical Hospital from January to December 2021, including the main clinical and laboratory parameters. Results. Among hospitalized patients with COVID-19, patients with T2DM had a higher mortality rate. An analysis of the case histories of deceased patients with COVID-19 and T2DM showed that at admission, body mass index (BMI), C-reactive protein, and creatinine were higher than those of survivors and amounted to BMI - 33 [30; 39] and 33 [28; 36] kg/m3; p=0.039, C-reactive protein - 77 [47.5; 106.0] and 57 [27.0; 89.0] mg/l; p=0.015, in terms of creatinine level - 89 [70.0; 144.0] and 82 [66.0; 101.0] µmol/l; p=0.039, respectively. It was found that in the second week of hospitalization in the group of deceased patients with COVID-19 and T2DM, the creatinine level was statistically significantly higher than in surviving patients and amounted to 94.5 [71.5; 141.0] and 72.5 [57.0; 88.0] µmol/L; p<0.001, respectively. The probability of death in hospitalized patients with type 2 COVID-19 and T2DM depended on BMI and creatinine levels at the second week of hospitalization. Patients with prehospital correction of hyperglycemia dipeptidyl peptidase-4 inhibitors (iDPP-4)/ glucagon-like peptide-1 receptor agonists (agGLP-1)/ sodium-glucose co-transporter 2 inhibitors (iSGLT-2) had significantly lower creatinine levels at week 2 of hospitalization. CONCLUSION: In patients with moderate to severe COVID-19 with concomitant T2DM, special attention should be paid to the combination of high BMI and creatinine in the second week of hospitalization, which is a prognostically unfavorable predictor of death in such patients.

[The determination of etatsizin in cadaveric material]. / Oprdelenie étatsizina v trupnom materiale.

Methods for ethacizine isolation from cadaveric material by acetonitrile acidified with 10% oxalic acid to attain pH 2.0 followed by ether purification have been developed. Extraction photo-colorimetry using methyl orange was used for measurement of ethacizine isolated from cadaveric material.

[Maximum permissible level of disseminated laser radiation with the wave length of 0.44 mkm]. / Predelno dopustimyi uroven rasseiannogo lazernogo izlucheniia s dlinoi volny v 0.44 mkm.

There where investigated the local and general reactions of 48 male rabbits (chinchilla) exposed to diffused laser radiation with wavelength of 0.44 microns. In the experiments 120 days period of exposure followed by 30 days period of rest. The maximal permissible level for laser radiation was established.

[The determination of pyrazidol in blood and urine]. / Opredelenie pirazidola v krovi i moche.

Methods of pyrazidole isolation from blood and urine as well as of its identification and quantification are developed. These methods allow one to isolate 53-55% of pyrazidole from blood and 90-95%, from urine.

[Use of spin-labelled substrate analogs for a comparative study of microsomal cytochrome P-450 and P-448]. / Ispol'zovanie spin-mechenykh analogov substratov dlia sravnitel'nogo izucheniia mikrosomal'nykh tsitokhromov P-450 i P-448.

The previously described, iodine-labeled alkylating stable nitroxyl radicals located at different distances between the N-O. group and the iodine atom were used for a comparative study of the structure of microsomal cytochromes P-450 and P-448 active centers. The radicals were shown to change the optical spectra of Fe3+ located in the active site of the enzyme that are similar to those induced by cytochrome P-450 substrates. Some differences in the type of the radicals binding to control, phenobarbital- and 3-methylcholanthrene-induced microsomes were revealed. The alkylating radical substrate analogs covalently bound to microsomal cytochrome P-450 in the vicinity of the active center, resulting in the inhibition of oxidation of type I and II substrates (e. g., aniline and naphthalene). The value of the spectral binding constant (Ks) for naphthalene in the presence of the radical covalently bound to the cytochrome P-450 active center showed a tendency to increase. Using the ESR technique, the interaction between Fe3+ and the radical localized in the active site of cytochrome P-450 was demonstrated. The contribution of Fe3+ to the relaxation of the radicals covalently bound to cytochrome P-450 was evaluated from the values of the spin label ESR spectra saturation curves at 77K. The distances between the N-O. group of these radicals and Fe3+ in the enzyme active center for the three types of microsomes were determined. The data obtained point to structural peculiarities of the active center of cytochrome P-450, depending on the microsomal type.

[Interactions of microsomal cytochrome P-450 with spin-labeled substrate analogs]. / Vzaimodeistvie mikrosomal'nogo tsitokhroma P-450 so spin-mechenymi analogami substratov.

The iodine-containing stable iminoxyl radicals with various distances between the N-O-group and the iodine atom are proposed to be used to study the structure of the active center of the microsomal cytochrome P-450. The radicals used induce changes in the optical spectra of the Fe3+ ion located in the active center of the enzyme, as in the case of type 1 substrates and inhibit essentially the microsomal oxidation of cytochrome P-450 substrates of type 1 and 2. This inhibition is neither due to suppression of the NADPH-cytochrome c reductase activity nor to cytochrome P-450 conversion to cytochrome P-420. Cytochrome P-450 substrates (aminopyrine) protect the enzyme against the radical-induced inactivation. The iodine-containing radicals are covalently bound to cytochrome P-450 in the vicinity of active center. The values of dissociation constants for the reversible enzyme-radical constants and the rate constants for the monomolecular transformation in the complex, k, were determined. The EPR method was used to detect the coupling between Fe3+ and the radical located in the active center of cytochrome P-450. The saturation curves of radical SPR spectra at 77 degrees K were employed to determine the contribution of Fe3+ to the relaxation time, T1, of the radicals covalently bound to cytochrome P-450 and to estimate the distances between the Fe3+ ion and the N-O-group of these radicals in the enzyme active center.

Interaction of the substrate analogue of cytochrome P-450 and mixed function oxidases.

The interaction of a spin labeled compound carrying an alkylating group 4-(3-iodo-2-oxopropylidene)-2,2,3,5,5-pentamethylimidozolydene-1-oxyl (RJ) and capable of binding covalently to mixed function oxidases (MFO) was studied. Measurements of the difference spectrum of cytochrome P-450 demonstrated that RJ induces spectral changes characteristic of type I substrates (lambda max = 403 nm; lambda min = 418 nm). The spectral binding constant (Ks) was 66 microM as determined from the difference spectrum. RJ inhibited the microsomal oxidation of substrates of cytochrome P-450 (aniline, aminopyrine and benzo [a]pyrene). This inhibition was shown not to be associated with the conversion of cytochrome P-450 to cytochrome P-420, or with the suppression of the activities of NADPh-cytochrome c reductase and NADPH-cytochrome P-450 reductase. Thus, evidence was obtained for the possible interaction of RJ with cytochrome P-450. RJ injected to rats (5 mg/100 g body wt, i.p.), inhibited the hydroxylation of benzo[a]pyrene, a type I substrate, (21%) and aniline, a type II substrate, (40%) in the microsomes from their livers. The presence of a paramagnetic center in RJ made it possible to study its interaction with microsomes. The electron paramagnetic resonance (EPR) spectrum of RJ was recorded in the rat liver microsomal fraction after in vivo administration of RJ. In rats treated with RJ (5 mg/100 g), hexobarbital sleeping time was prolonged 1.5-fold. Alkylating analogs of substrates of cytochrome P-450 are suggested as agents for structural studies of the active center of cytochrome P-450 and the development of efficient inhibitors of reactions catalyzed by this enzyme.