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INTRODUCTION                                        constitute  a substantial  number  of publications but  an
                                                              overall low amount of evidence. Evidence is lacking on the
          Wound healing is a self‑regulated physiological  process   use of an intermittent  negative pressure dressing which
          of cell regeneration which occurs without any external   would  be more economical  and clinically  acceptable
                                                                                                             [17]
          stimuli. This is accomplished by the stages of fibroplasia,   than the use of continuous NPWT.
          angiogenesis,  and migration  of fibroblasts, endothelial,   The present study evaluates the role of intermittent negative
          and epithelial cells, finally leading to the wound   pressure using limited access dressing  (LAD) (a cycle of
          contraction.   Inflammation  is  a  vital  and protective   30  min  of  suction  and  3.5  h  of  rest)  on  diabetic  wounds
                    [1]
          response instigated by injured cells at the wound site   by measuring and comparing the levels of hydroxyproline,
          which begins the process of tissue repair.  In response to
                                             [2]
          inflammation,  reactive  oxygen  species  (ROS)  such  as  free   total protein, NO, antioxidants  (GSH), and an oxidative
          radicals  (superoxide  anion  radical: O ) and nonradical   biomarker malondialdehyde (MDA) in the granulation tissue
                                           −
                                           2
          hydrogen  peroxide  (H O ), are  generated  continuously   of type 2 diabetes mellitus ulcer patients.
                                2
                              2
          until inflammation subsidies.  Free radicals  and their
                                   [3]
          scavenging systems play an important role in normal and   METHODS
          delayed wound healing. [4,5]
                                                              Ethical approval and informed consent
          Delayed healing of diabetic wounds is characterized by an   This prospective randomized controlled  trial study was
          increase in matrix metalloproteinases  (MMPs), a decrease   carried out in the Department of Plastic Surgery, Kasturba
                                                          [6]
          in the  tissue  inhibitors  of metalloproteinases  (TIMPs),    Hospital, Manipal. The Institutional Ethics Committee
          and an altered magnitude  of free  radical generation  and   reviewed  and approved the study protocol. Written
          disposal.  An imbalance between oxidant and antioxidant
                 [7]
          defense mechanisms  leads to oxidative stress resulting   informed consent was obtained from all patients or their
          in lipid peroxidation, DNA damage, and inactivation of   next of kin prior to inclusion in the study.
                                      [8]
          free  radical scavenger  enzymes.   This  leads to tissue   Study design
          damage and impairs  the healing process in diabetic   Patients were diagnosed on the basis of history, physical
          wounds with reduced  angiogenesis,  altered proliferation   examination, and biochemical investigation. Seventy‑five
          of fibroblasts, reduced fibroblast migration,  inadequate   patients  more  than 40  years  of  age  (mean  age:  56  years)
          collagen  deposition, advanced glycation, and  abnormal   suffering from chronic diabetic wounds with insulin‑controlled
          mitochondrial function. [9‑11]                      diabetes were enrolled in the study. After evaluation for
          Nitric oxide (NO) is a mediator which plays an important   inclusion (diabetic leg ulcers) and exclusion criteria (collagen
          role in  wound  healing  and has been  implicated in   disorders,  leprosy,  pregnancy,  cirrhosis,  and  HIV  positive
          diabetic wounds. Reduced levels can cause alterations   status), 55 patients were randomized of whom 27 were
          in  vascular permeability  and a reduction of capillary   assigned  to  the  LAD  group  and  28  were  assigned  to the
          flow causing oxidative stress.  Antioxidants such as   conventional dressing group. Biopsies were taken from both
                                     [12]
          reduced glutathione (GSH), glutathione peroxidase (GPx),   groups on day 0 of the study. The LAD group patients were
          catalase (CAT), and thiol (‑SH) prevent the generation and   treated with intermittent negative pressure and a moist
          action of ROS. Hence, antioxidants that provide potential   wound environment, and wounds were washed daily with
          mechanisms  for wound healing  can ameliorate  diabetic   a solution of povidone‑iodine. Conventional dressing group
          complications  by both significantly preventing tissue   patients were dressed daily with 5% povidone‑iodine solution
          damage and stimulating the wound healing process. [13,14]  soaked gauze. On day 10, granulation tissue biopsies were
                                                              taken from both groups and subjected to biochemical study
          Several  studies  have demonstrated the  negative  role of
          free radicals on wound healing; reduction of persistent   by an investigator blinded to the clinical data.
          inflammation; and elimination  of free radicals may   Randomization
          improve healing in diabetic wounds.  Although advanced   Patients were randomized by generating tables of random
                                        [15]
          technologies  have  been  developed for the  treatment  of   numbers through www.random.org. Numbers were
          diabetic wounds, outcomes have been  poor. Negative   assigned  to a treatment  group and sealed in opaque
          pressure  wound therapy (NPWT) has emerged as a     envelopes containing labeled paper  with the treatment
          treatment  for complex wounds. This  is  a noninvasive   and the patient’s ID.
          system which creates a localized and  controlled  sub
          atmospheric  pressure  environment.  Wound healing  by   Chemicals
          delayed primary  or secondary intention  is  promoted   All chemical used were of analytical grade. Standard
          by  the  creation of a moist  wound environment  which   L‑hydroxyproline, bovine serum albumin (BSA), standard
          prepares the wound bed for closure, reduces edema, and   GSH, 1‑chloro‑2,4‑dinitrobenzene, and cumene H O  were
                                                                                                        2
                                                                                                         2
          promotes the formation and perfusion of granulation   purchased from  Sigma‑Aldrich  (St.  Louis,  MO,  USA).
          tissue. [16,17]  The clinical  evidence supporting the use of   Thiobarbituric  acid (TBA), trichloroacetic acid (TCA),
          continuous NPWT on diabetic wounds has been based   1,1,3,3‑tetramethoxypropane N‑ethylmaleimide  (NEM),
          largely  on  clinician  perception,  case  series,  small  cohort   and orthophosphoric acid were  purchased from  S.D.
          studies, and weakly powered randomized trials that   Fine‑Chemicals Ltd. (Boisar, India).


          Plast Aesthet Res || Vol 2 || Issue 5 || Sep 15, 2015                                             267
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