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Biomedical subjects

I A Kozlov

Publications and source records attributed to I A Kozlov.

At least 19 recordsLinked to original sources
PubMed2004

[Anatomic conditions for isolated proximal resection of the pancreas].

Based on summarized data of the literature it is concluded that proximal resection of the duodenum in chronic pancreatitis with lesion of the pancreatic head is possible only bearing in mind variability of arterial blood supply. Experience of surgical treatment of 19 patients with chronic pancreatitis who underwent isolated resections of pancreatic head due to inflammatory changes of pancreas' proximal parts demonstrates expediency of this surgery. Maximal resection of pancreatic tissue permits to decrease risk of purulent and inflammatory complications and promotes favorable course after surgery.

Chronic Disease↗
PubMed2003

[Pancreatoduodenal resection with preservation of the pylorus].

Experience with 106 pancreatoduodenal resections (PDR) with pylorus savage for tumors and benign diseases of pancreatic head and periampullar zone is analyzed. Features of mobilization of pancreatoduodenal complex in PDR are shown. They permit to reduce the rate of complications (gastrostasis). Necessity of differential approach to choice of creation of biliodigestive anastomosis is demonstrated. Risk of postoperative pancreatitis is highest in non-dilated pancreatic duct and small-changed pancreatic parenchyma. In these cases terminolateral pancreatojejunostomy with external drainage of pancreatic duct (12 patients) and pancreatogastrostomy (21) are preferable. PDR with pylorus savage permitted to use wider pancreato-, bilio- and duodenoenteroejunoanastomosis on one loop of the jejunum. Gastrostasis was seen in 50% patients after PDR with pylorus savage. Technical features of surgery and also postoperative complications leading to gastrostasis are demonstrated.

Humans↗
PubMed2003

[Surgical treatment of chronic pancreatitis in combination with duodenal ulcer disease].

Results of two surgeries--total and subtotal resection of pancreatic head in combination with selective proximal vagotomy (SPV)--performed for chronic pancreatitis and duodenal ulcer disease (DUD) are presented. In one case surgery was supplemented with circular resection of the duodenum and fundoplication. Reconstructive stage of both surgeries included creation of pacreato- and biliodigestive anastomosis on Roux intestinal loop. Choledochojejunoanastomosis was created on the same loop of the small intestine either "end-to-side" with supraduodenal part of common bile duct or "side-to-side" with its pancreatic part. The former surgery was finished with duodenoduodenoanastomosis "end-to-end" for recovery of duodenal passage. This surgery was characterized by complete removal of pancreatic head. The latter surgery corresponded to Beger's operation. There were no complications in the nearest postoperative period. Long-term results were favorable and followed up during 17.5 and 7 months, respectively. This experience testifies that resection of pancreatic head with SPV may be considered as alternative to pancreatoduodenal resection in surgical treatment of patients with chronic pancreatitis.

Adult↗
PubMed2001

Synthesis of solid-supported mirror-image sugars: a novel method for selecting receptors for cellular-surface carbohydrates.

We introduced a novel method, through mirror-image phage display, for the identification of high-affinity D-peptides to target specific cell-surface carbohydrates. Both 3-deoxy-alpha-L-manno-2-octulosonic acid (L-KDO) and L-sialic acid and an L-sialo-disaccharide have been synthesized and attached to a solid support for selection of high-affinity peptide binders displayed on phages. Our initial studies in this effort produce single-chain Fab sequences and dodecapeptides that bind to sialic acid and KDO with nanomolar and high micromolar affinity.

Amino Acid Sequence↗
PubMed2000

Nonenzymatic template-directed reactions on altritol oligomers, preorganized analogues of oligonucleotides.

Altritol nucleic acids (ANAs) are RNA analogues with a phosphorylated D-altritol backbone. The nucleobase is attached at the 2-(S)-position of the carbohydrate moiety. We report that ANA oligomers are superior to the corresponding DNA, RNA, and HNA (hexitol nucleic acid) in supporting efficient nonenzymatic template-directed synthesis of complementary RNAs from nucleoside-5'-phosphoro-2-methyl imidazolides. Activated ANA and HNA monomers do not oligomerize efficiently on DNA, RNA, HNA, or ANA templates.

Chemistry↗
PubMed1999

Nonenzymatic synthesis of RNA and DNA oligomers on hexitol nucleic acid templates: the importance of the A structure.

Hexitol nucleic acid (HNA) is an analogue of DNA containing the standard nucleoside bases, but with a phosphorylated 1,5-anhydrohexitol backbone. HNA oligomers form duplexes having the nucleic acid A structure with complementary DNA or RNA oligomers. The HNA decacytidylate oligomer is an efficient template for the oligomerization of the 5'-phosphoroimidazolides of guanosine or deoxyguanosine. Comparison of the oligomerization efficiencies on HNA, RNA, and DNA decacytidylate templates under various conditions suggests strongly that only nucleic acid double helices with the A structure support efficient template-directed synthesis when 5'-phosphoroimidazolides of nucleosides are used as substrates.

Catalysis↗
PubMed1999

Nonenzymatic oligomerization reactions on templates containing inosinic acid or diaminopurine nucleotide residues.

The template-directed oligomerization of nucleoside-5'-phosphoro-2-methyl imidazolides on standard oligonucleotide templates has been studied extensively. Here, we describe experiments with templates in which inosinic acid (I) is substituted for guanylic acid, or 2,6-diaminopurine nucleotide (D) for adenylic acid. We find that the substitution of I for G in a template is strongly inhibitory and prevents any incorporation of C into internal positions in the oligomeric products of the reaction. The substitution of D for A, on the contrary, leads to increased incorporation of U into the products. We found no evidence for the template-directed facilitation of oligomerization of A or I through A-I base pairing. The significance of these results for prebiotic chemistry is discussed.

2-Aminopurine↗
PubMed1999

Efficient transfer of information from hexitol nucleic acids to RNA during nonenzymatic oligomerization.

Hexitol nucleic acids (HNAs) are DNA analogues that contain the standard nucleoside bases attached to a phosphorylated 1,5-anhydrohexitol backbone. We find that HNAs support efficient information transfer in nonensymatic template-directed reactions. HNA heterosequences appeared to be superior to the corresponding DNA heterosequences in facilitating synthesis of complementary oligonucleotides from nucleoside-5'-phosphoro-2-methyl imidazolides.

Chromatography, High Pressure Liquid↗
PubMed1999

Oligomerization of deoxyguanosine 5'-phosphoro-2-methylimidazolide on a polycytidylate template.

The oligomerization of deoxyguanosine 5'-phosphoro-2-methylimidazolide on a polycytidylate template is much less efficient than the oligomerization of the corresponding activated ribonucleotide. Nonetheless oligomers containing up to eight nucleotide residues are detected. The products are 3'-5'-linked oligodeoxyribonucleotides capped at the 5'-terminus with a pyrophosphate-linked monomer.

Chromatography, High Pressure Liquid↗
PubMed1998

Oligomerization of activated D- and L-guanosine mononucleotides on templates containing D- and L-deoxycytidylate residues.

The oligomerization of activated D- and L- and racemic guanosine-5'-phosphoro-2-methylimidazole on short templates containing D- and L-deoxycytidylate has been studied. Results obtained with D-oligo(dC)s as templates are similar to those previously reported for experiments with a poly(C) template. When one L-dC or two consecutive L-dCs are introduced into a D-template, regiospecific synthesis of 3'-5' oligo(G)s proceeds to the end of the template, but three consecutive L-dCs block synthesis. Alternating D-,L-oligomers do not facilitate oligomerization of the D-, L-, and racemic 2-guanosine-5'-phosphoro-2-methylimidazole. We suggest that once a "predominately D-metabolism" existed, occasional L-residues in a template would not have led to the termination of self-replication.

Dimerization↗