Enhanced Surgical Techniques in Orthopedics: A Comprehensive Guide for Surgeons Based on Modification of the McFarland and Osborne Approach to the Hip.

Introduction: The implementation of various approaches in hip arthroplasties introduces distinct advantages and complications. Notably, widely adopted methods such as the posterior approach have been linked to elevated rates of posterior hip dislocations and iatrogenic sciatic nerve injuries, while the lateral approach has been associated with superior gluteal nerve injuries. In this study, we propose a refined modification of the McFarland and Osborne approach, aiming to amalgamate the most favorable aspects of prior modifications of the lateral approach to the hip.

Wooden stick penetration from the perineal region up to the thorax.

Background: Penetrating injuries of the perineum are rare but very dangerous. Since the genitourinary and colorectal organs may be injured, how to evaluate surgical management of the injury is very important.

Methods: The present report presents a case of penetrating injury of the perineum by a wooden stick when the patient fell on the upright wooden stick from a tree.

Road traffic accidents in hilly regions of northern India: What has to be done?

Background: Road traffic accidents (RTA) are responsible for 1.2 million deaths worldwide each year. RTA will become the 3(rd) largest contributor to the global burden of diseases after ischemic heart diseases (IHD) and depression.

Traumatic loss of talus: a rare injury.

Background: Traumatic loss of talus during a compound injury of ankle is an unusual injury.

Objective: We report a 55 years old woman who sustained an open ankle injury with complete extrusion of talus and loss at the injury site.

Method: A tricortical bone graft was obtained from iliac crest and talar dimensions carved with 5 cm length and 3 cm height given by buttressing fibular graft between them.

Catalytic residues are shared between two pseudosubunits of the dehydratase domain of the animal fatty acid synthase.

Expression, characterization, and mutagenesis of a series of N-terminal fragments of an animal fatty acid synthase, containing the beta-ketoacyl synthase, acyl transferase, and dehydratase domains, demonstrate that the dehydratase domain consists of two pseudosubunits, derived from contiguous regions of the same polypeptide, in which a single active site is formed by the cooperation of the catalytic histidine 878 residue of the first pseudosubunit with aspartate 1032 of the second pseudosubunit. Mutagenesis and modeling studies revealed an essential role for glutamine 1036 in anchoring the position of the catalytic aspartate. These findings establish that sequence elements previously assigned to a central structural core region of the type I fatty acid synthases and some modular polyketide synthase counterparts play an essential catalytic role as part of the dehydratase domain.

Biological approach to treatment of intra-articular proximal tibial fractures with double osteosynthesis.

The treatment of intra-articular proximal tibial fractures is associated with complications, and much conflicting literature exists concerning the treatment of choice. In our study, an attempt has been made to develop an ideal and adequate treatment protocol for these intra-articular fractures. The principle of double osteosynthesis, i.

Coupling of the de novo fatty acid biosynthesis and lipoylation pathways in mammalian mitochondria.

The objective of this study was to identify the products and possible role of a putative pathway for de novo fatty acid synthesis in mammalian mitochondria. Bovine heart mitochondrial matrix preparations were prepared free from contamination by proteins from other subcellular components and, using a combination of radioisotopic labeling and mass spectrometry, were shown to contain all of the enzymes required for the extension of a 2-carbon precursor by malonyl moieties to saturated acyl-ACP thioesters containing up to 14 carbon atoms. A major product was octanoyl-ACP and, in the presence of the apo-H-protein of the glycine cleavage complex, the newly synthesized octanoyl moieties were translocated to the lipoylation site on the acceptor protein.

Effect of modification of the length and flexibility of the acyl carrier protein-thioesterase interdomain linker on functionality of the animal fatty acid synthase.

A natural linker of approximately 20 residues connects the acyl carrier protein with the carboxy-terminal thioesterase domain of the animal fatty acid synthase. This study examines the effects of changes in the length and amino acid composition of this linker on catalytic activity, product composition, and segmental motion of the thioesterase domain. Deletion of 10 residues, almost half of the interdomain linker, had no effect on either mobility of the thioesterase domain, estimated from fluorescence polarization of a pyrenebutyl methylphosphono moiety bound covalently to the active site serine residue, or functionality of the fatty acid synthase; further shortening of the linker limited mobility of the thioesterase domain and resulted in reduced fatty acid synthase activity and an increase in product chain length from 16 to 18 and 20 carbon atoms.

Structure and molecular organization of mammalian fatty acid synthase.

De novo synthesis of fatty acids in the cytosol of animal cells is carried out by the multifunctional, homodimeric fatty acid synthase (FAS). Cryo-EM analysis of single FAS particles imaged under conditions that limit conformational variability, combined with gold labeling of the N termini and structural analysis of the FAS monomers, reveals two coiled monomers in an overlapping arrangement. Comparison of dimeric FAS structures related to different steps in the fatty acid synthesis process indicates that only limited local rearrangements are required for catalytic interaction among different functional domains.

Cloning, expression, and characterization of the human mitochondrial beta-ketoacyl synthase. Complementation of the yeast CEM1 knock-out strain.

A human beta-ketoacyl synthase implicated in a mitochondrial pathway for fatty acid synthesis has been identified, cloned, expressed, and characterized. Sequence analysis indicates that the protein is more closely related to freestanding counterparts found in prokaryotes and chloroplasts than it is to the beta-ketoacyl synthase domain of the human cytosolic fatty acid synthase. The full-length nuclear-encoded 459-residue protein includes an N-terminal sequence element of approximately 38 residues that functions as a mitochondrial targeting sequence.

Head-to-head coiled arrangement of the subunits of the animal fatty acid synthase.

The role of the beta-ketoacyl synthase domains in dimerization of the 2505 residue subunits of the multifunctional animal FAS has been evaluated by a combination of crosslinking and characterization of several truncated forms of the protein. Polypeptides containing only the N-terminal 971 residues can form dimers, but polypeptides lacking only the N-terminal 422 residue beta-ketoacyl synthase domain cannot. FAS subunits can be crosslinked with spacer lengths as short as 6 A, via cysteine residues engineered near the N terminus of the full-length polypeptides.

Intimal thickness is not associated with wall shear stress patterns in the human right coronary artery.

Objective: Low wall shear stress has been implicated in atherogenesis throughout the arterial tree, including the right coronary artery (RCA). The objective of this study was to determine the level of covariation of intimal thickness and wall shear stress in the human RCA.

Methods And Results: Postmortem histological measurements of intimal thickness were compared with wall shear stresses calculated from computational flow modeling in 4 human right coronary arteries.

Characterization of the beta-carbon processing reactions of the mammalian cytosolic fatty acid synthase: role of the central core.

The properties of the beta-ketoacyl reductase, dehydrase, and enoyl reductase components of the animal fatty acid synthase responsible for the reduction of the beta-ketoacyl moiety formed at each round of chain elongation have been studied by engineering and characterizing mutants defective in each of these three catalytic domains. These "beta-carbon processing" mutants leak the stalled four-carbon intermediates by direct transfer to CoA. However, enoyl reductase mutants leak beta-ketobutyryl, beta-hydroxybutyryl, and crotonyl moieties, a finding explained, at least in part, by the observation that the equilibrium and rate constant for the dehydrase reaction favor the formation of beta-hydroxy rather than enoyl moieties.

Cloning, expression, characterization, and interaction of two components of a human mitochondrial fatty acid synthase. Malonyltransferase and acyl carrier protein.

The possibility that human cells contain, in addition to the cytosolic type I fatty acid synthase complex, a mitochondrial type II malonyl-CoA-dependent system for the biosynthesis of fatty acids has been examined by cloning, expressing, and characterizing two putative components. Candidate coding sequences for a malonyl-CoA:acyl carrier protein transacylase (malonyltransferase) and its acyl carrier protein substrate, identified by BLAST searches of the human sequence data base, were located on nuclear chromosomes 22 and 16, respectively. The encoded proteins localized exclusively in mitochondria only when the putative N-terminal mitochondrial targeting sequences were present as revealed by confocal microscopy of HeLa cells infected with appropriate green fluorescent protein fusion constructs.

Cloning, expression, and characterization of a human 4'-phosphopantetheinyl transferase with broad substrate specificity.

A single candidate 4'-phosphopantetheine transferase, identified by BLAST searches of the human genome sequence data base, has been cloned, expressed, and characterized. The human enzyme, which is expressed mainly in the cytosolic compartment in a wide range of tissues, is a 329-residue, monomeric protein. The enzyme is capable of transferring the 4'-phosphopantetheine moiety of coenzyme A to a conserved serine residue in both the acyl carrier protein domain of the human cytosolic multifunctional fatty acid synthase and the acyl carrier protein associated independently with human mitochondria.

Structural and functional organization of the animal fatty acid synthase.

The entire pathway of palmitate synthesis from malonyl-CoA in mammals is catalyzed by a single, homodimeric, multifunctional protein, the fatty acid synthase. Each subunit contains three N-terminal domains, the beta-ketoacyl synthase, malonyl/acetyl transferase and dehydrase separated by a structural core from four C-terminal domains, the enoyl reductase, beta-ketoacyl reductase, acyl carrier protein and thiosterase. The kinetics and specificities of the substrate loading reaction catalyzed by the malonyl/acetyl transferase, the condensation reaction catalyzed by beta-ketoacyl synthase and chain-terminating reaction catalyzed by the thioesterase ensure that intermediates do not leak off the enzyme, saturated chains exclusively are elongated and palmitate is released as the major product.

Engineering of an active animal fatty acid synthase dimer with only one competent subunit.

Animal fatty acid synthases are large polypeptides containing seven functional domains that are active only in the dimeric form. Inactivity of the monomeric form has long been attributed to the obligatory participation of domains from both subunits in catalysis of substrate loading and condensation reactions. However, we have engineered a fatty acid synthase containing one wild-type subunit and one subunit compromised by mutations in all seven functional domains that is active in fatty acid synthesis.

Mechanism of the beta-ketoacyl synthase reaction catalyzed by the animal fatty acid synthase.

The catalytic mechanism of the beta-ketoacyl synthase domain of the multifunctional fatty acid synthase has been investigated by a combination of mutagenesis, active-site titration, product analysis, and product inhibition. Neither the reactivity of the active-site Cys161 residue toward iodoacetamide nor the rate of unidirectional transfer of acyl moieties to Cys161 was significantly decreased by replacement of any of the conserved residues, His293, His331, or Lys326, with Ala. Decarboxylation of malonyl moieties in the fully-active Cys161Gln background generated equimolar amounts of acetyl-CoA and bicarbonate, rather than carbon dioxide, and was seriously compromised by replacement of any of the conserved basic residues.