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Biomedical subjects

M Surma

Publications and source records attributed to M Surma.

At least 19 recordsLinked to original sources
PubMed2003

Synthesis of standards of the most important markers of Leuckart p-methoxymethamphetamine (PMMA). Examination of the influence of experimental conditions and a drug diluent on SPE/TLC profiling.

The synthesis of characteristic markers of PMMA obtained by Leuckart method was described. The effectiveness of a procedure of SPE/TLC screening profiling of impurities was studied on the basis of selected impurities. The influence of glucose (a drug diluent) on the profile quality was investigated. The intermediate product (characteristic for the Leuckart synthesis) N-formyl-p-methoxymethamphetamine (1) and by-products: N-formyl-p-methoxyamphetamine (2), p-methoxyamphetamine (3), N,N-dimethyl-p-methoxyamphetamine (4), (RS) and (RR/SS) diastereoisomers of bis(1-methyl-2-(4-methoxyphenyl)ethyl)amine (meso-5 and rac-5), (RS) and (RR/SS) diastereoisomers of N-methyl-bis(1-methyl-2-(4-methoxyphenyl)ethyl)amine (meso-6 and rac-6), N-methyl-1,3-bis(4-methoxyphenyl)propane-2-amine (7) were synthesized. The substrate p-methoxyphenylacetone and the impurities 1 and 4 were used in the study of influence of experimental conditions and glucose on the profiling process and results. The experiments were carried out according to a 2(4) factorial design. The proposed criterions of the profile quality are based on matrix presentation of TLC patterns. They take into account the number of spots revealed, differences between R(f) values and intensity of fluorescence, simultaneously.

Amphetamines↗
PubMed2001

Genetic diversity among cultivars of spring barley revealed by random amplified polymorphic DNA (RAPD).

RAPD (random amplified polymorphic DNA) polymorphism was studied in 23 malting and non-malting spring barley cultivars included in the official list of Polish cultivated varieties. Twenty-four 10-mer primers were tested in each cultivar, giving altogether 149 amplification products, 45% of which were polymorphic. The number of polymorphic bands revealed by one primer ranged from 1 to 6, with an average of 2.8. Genetic distance for all pairs of compared varieties was estimated and a dendrogram was constructed using unweighted pair group method of arithmetic means. The genetic distance between cultivars ranged from 0.11 for cvs. Apex and Bryl to 0.62 for cvs. Orthega and Madonna. Of the seven malting cultivars only two (Brenda and Stratus) formed one group at D = 0.25. The genetic distance between cvs. Brenda and Scarlett, especially recommended for brewery, was equal to 0.34. The detected polymorphism appeared to be sufficient for assessing genetic distances between cultivars, but on the basis of this polymorphism groups of malting and non-malting cultivars were not clearly distinguished.

Journal Article↗
PubMed2000

X-ray diffraction study of human serum.

Blood serum from people suffering from cancer and healthy subjects was subjected to a comparative study by X-ray diffraction. The diffraction patterns were referred to that of pure water. The patterns obtained for blood serum of healthy subjects were similar to that of pure water, while those of cancer patients (two kinds of cancer changes) were different. The former similarity is accounted for by the dominant interaction of water molecules in healthy blood serum with non-polar side chains of amino acids, stabilising the serum structure. In samples from cancer patients the structure of water in blood serum is destroyed because of enhanced interactions of water with polar molecules of conformationally changed proteins. This observation suggests X-ray examination of blood serum from cancer patients and healthy subjects, indicating X-ray diffraction as a diagnostic tool for the occurrence of cancer. The results of this work have shown that the presence of protein affected by cancer has a destructive effect on the structure of water in human serum. The results reported confirm the earlier finding relating cancer changes to optical circular birefringence effects.

Humans↗
PubMed2000

Genetic determination of variability of barley doubled haploids inoculated with Fusarium culmorum (W.G.Sm.) Sacc. with regard to mycotoxin accumulation and reduction in yield traits.

The genetic determination of variability of barley doubled haploid (DH) lines in regard of their susceptibility to Fusarium head blight caused by Fusarium culmorum was studied. The susceptibility was evaluated in 3-year field experiment on the basis of reduction in yield traits and myotoxin accumulation in infected kernels. The following traits were analysed in inoculated and control plants: kernel number and weight per ear, 1000-kernel weight, percentage of plump kernels (>2.5 mm), deoxynivalenol (DON) content and nivalenol (NIV) content of kernels. On the basis of the obtained data, heritability coefficient (ratio of genotypic to phenotypic variance) was assessed, and genetic parameters as well as the number of effective factors were estimated. Heritability coefficients calculated from two-way analysis of variance, i.e.regarding the influence of years and year x genotype interaction, appeared to be exceptionally low and ranged from 5.2% for the reduction in plump kernels to 38.2% for the reduction in 1000-kernel weight. In the case of mycotoxin accumulation about 60% of the observed variability in NIV concentrations and 30% in DON concentration resulted form genetic differences among lines. Additive effects of genes were important for all the analysed traits. Significant effects of dominance and dominance x dominance were observed for 1000-kernel weight and percentage of plump kernels. Moreover, it was found that the observed variability in yield trait reduction resulted from segregation of 5-6 effective factors, DON contents from 4 factors, while NIV content from 5 factors.

Journal Article↗
PubMed1983

Comparative evaluation of renoscintigraphic properties and plasma clearance of 99MTc-DADS (99mTc-N,N'-bis/mercaptoacetamido ethylenediamine), 99mTc-DTPA and 131I-o-hippuran.

Plasma clearance of 99mTc-N,N'-bis (1,2-mercaptoacetamido) ethylenediamine (DADS), 99mTc-DTPA and 131I-o-hippuran (OIH) was determined in rabbits from blood-concentration decay curves after single i.v. injection of the compounds. Dynamic scintigraphy was performed using the same three compounds, and "activity" curves were compared as observed over kidney ROIs. Both clearance values and renoscintigraphic curves were similar for 99mTc-DADS and 99mTc-DTPA but evidently different from those of OIH. Biliary excretion of 99mTc-DADS was also observed. It appears that, in contrast to other authors, 99mTc-DADS cannot serve as a substitute for 131I-o-hippuran.

Animals↗
PubMed1981

Nonenzymatic glycosylation of basement membranes: in vitro studies.

Incubation of purified rat glomerular basement membrane (GBM) with [14C]-glucose in vitro resulted in the incorporation of [14C] into acid-precipitable radioactivity in a reaction that was time and temperature dependent. Findings with rat lens capsule basement membrane (LCBM), an anatomically distinct but chemically similar extracellular matrix, incubated for varying times at different temperatures with [14C]-glucose at constant specific activity were similar. Nonenzymatic glycosylation of basement membrane, documented by hydroxymethylfurfuraldehyde generation after incubation with unlabeled glucose, increased in proportion to the ambient glucose concentration over a range of 5--100 mM. Acid-precipitable radioactivity also increased in proportion to [14C]-glucose concentration, although this method overestimated glycosylation about 15-fold at 5--20 mM glucose and 50-fold at 50--100 mM glucose. Coupled with recent in vivo studies, these findings indicate that exposure to increased glucose concentration alters the chemistry of glomerular and other basement membranes. Since accumulation of basement membrane characterizes several of the microangiopathic sequelae of diabetes, the role of increased nonenzymatic glycosylation on the structure, function, and metabolism of basement membrane warrants investigation.

Animals↗
PubMed1980

Renal glomerular basement membrane. In vivo biosynthesis and turnover in normal rats.

Glomerular basement membrane was labeled in vivo by the injection of tracer amounts of radioactive glycine and proline, and subsequently purified by osmotic lysis followed by sequential treatment with detergents. Analysis of tail tendons from these animals allowed comparison of basement membrane biosynthesis and degradation with these parameters in the newly synthesized fractions of fibrillar collagen. Peak radiolabeling with [3H]glycine occurred within 24 h, declining steadily thereafter in both basement membranes and salt-soluble tail tendon collagen. Calculated turnover times for [3H]glycine-labeled glomerular basement membrane and salt-soluble tail collagen were similar. Turnover of the collagenous portion of glomerular basement membrane was slightly longer, comparable to the acetic acid-soluble fraction of fibrillar collagen. Glomerular basement membrane is readily labeled after parenteral injection of radioactive precursors. Its biologic half-life is comparable to that of soluble fibrillar collagen, indicating a more rapid turnover than previously believed.

Animals↗
PubMed1979

A method for subtraction of the extrarenal "background" in dynamic 131I-hippurate renoscintigraphy.

Using a Toshiba GC-401 gamma camera with MDS computer Trinary a new method was developed for subtracting the extrarenal (extracanalicular) "background" from the count rate recorded over the kidneys after intravenous administration of 131I-hippurate. Mean subtraction factors of the "blood" activity curve were calculated from a study of 27 patients who were given 51Cr-HSA for purposes of conventional renography with "background" subtraction. The values of the mean subtraction factors FR,L for the right and left kidney, by which a blood count rate should be multiplied amounted to 0.86 +/- 0.12 and 0.79 +/- 0.13, respectively. A comparison of the coefficients of variation of the pure renal signal when mean vs. individually determined subtraction factors were used, and the verification of the method in unilaterally nephrectomized patients have demonstrated that determination of the factors, FR,L, for each patient individually is not required and sufficient precision can be obtained by using the method and factors reported in this study.

Chromium Radioisotopes↗