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Biomedical subjects

M Türegün

Publications and source records attributed to M Türegün.

16 recordsLinked to original sources

Treatment with cerium nitrate bathing modulate systemic leukocyte activation following burn injury: an experimental study in rat cremaster muscle flap.

It is suggested that burn toxin known as lipid protein complex (LPC) stimulates phagocytic cells that cause the release of a variety of inflammatory mediators which induce the activation of leukocytes. It is reported that cerium nitrate (CN) might fix LPC in eschar tissue and prevent LPC from entering the circulation. In this study, we tested the hypothesis that prevention or modulation of LPC initiated cell activation by fixing LPC in eschar tissue with CN treatment, would reduce the number of activated leukocytes, which is an important indicator of inflammation, in rat cremaster muscle flap model. Twenty-eight animals were studied in four groups--group I (control), only cremaster muscle flap was dissected; group II (burn injury), burn injury was performed and flap was dissected; group III (saline); and group IV (CN), following burn injury rats treated with saline and CN, respectively, and than flaps were dissected. Blood vessels were observed in vivo under an intravital microscopy system and the number of rolling, sticking, and transmigrating leukocytes were measured in each group. Burn injury significantly increased the number of activated leukocytes (P<0.001). We observed that CN treatment significantly reduced the number of activated leukocytes following burn injury (P<0.001). In conclusion, we demonstrated that CN treatment significantly decreased the activation of leukocytes, which plays an important role in systemic inflammation. Decreased leukocyte activation is interpreted as prevention or modulation of systemic inflammatory response following burn injury.

Administration, Topical↗

Cranial defect repair using e-PTFE: part I. Evaluation of bone stiffness.

Autologous bone grafts are the preferred material for craniofacial reconstruction, but such procedures lead to increased operative time and bleeding, donor site morbidity, and graft resorption. The efficacy of expanded-polytetrafluoroethylene (e-PTFE) sheets to increase bone regeneration and remodeling in cranial defects using a rabbit model was evaluated by mechanical testing. New Zealand white rabbits were divided into 3 groups and sacrificed 6 months after surgery. In the Split Table group, (n = 16), a bilateral bone defect was created on the outer table of the parietal bones. In the Full Table group, (n = 16), a bilateral defect was created through both the inner and outer table of the cranium. The control group, (n = 10) was subjected to a sham operation. Indentation testing was performed to determine the stiffness of newly formed bone in and around the defect. Near the center of the defect, Split Table defects repaired with e-PTFE resulted in significantly stiffer bone than regenerated control bone. The Full Table defects repaired with e-PTFE also resulted in bone significantly stiffer than control regenerated bone around the central region of the defect. The data supports the hypothesis that e-PTFE improves the repair of cranial defects in a rabbit model. It is surmised that the porosity of the e-PTFE provides a stable scaffold for migration of tissue regenerating cells, which may be preferentially localized near the cranial suture lines. This porosity may also provide a barrier to fibrous tissue regenerating cells.

Animals↗

Dose-dependent response to IFN-gamma in muscle flap microcirculation.

In this study, the authors attempted to determine the effects of intraarterial administration of various doses of Interferon-gamma (IFN-gamma) on microcirculation in a rat muscle flap model. In Group 1 (control), 0.6 ml vehicle solution-PBS-BSA, in Group 2 0.6 ml IFN-gamma (25 ng/ml), in Group 3 0.6 ml IFN-gamma (50 g/ml), in Group 4 0.6 ml IFN-gamma (100 g/ml), were injected. The diameter of the cremaster arterioles and venules, red blood cell velocities, the number of rolling leukocytes and lymphocytes, sticking leukocytes and lymphocytes, capillary perfusion, and endothelial edema index were evaluated. Deterioration of flow hemodynamics was confirmed by a significant decrease in flow velocity in the main artery (A1) (47 percent in Group 3 and 65 percent in Group 4). All dosages of IFN-gamma caused a statistically significant decrease in rolling leukocytes, but this effect was more obvious in the 25 ng/ml group. Injury to the vascular endothelium was confirmed by a two-fold increase in transmigrating leukocytes in the 100 ng/ml group. This was accompanied by 60 percent and 75 percent drops in capillary perfusion, and by 12 percent and 24 percent drops in the endothelial edema index in Groups 3 and 4, respectively. The results indicate that direct intraarterial administration of IFN-gamma in doses higher than 25 ng/ml may be toxic to muscle flaps.

Animals↗

Interferon-gamma improves muscle flap microcirculation in double-strand RNA-induced inflammation.

Endothelial cell (EC) activation and subsequent expression of leukocyte adhesion molecules are initial events in multiple pathological processes. Viral double-strand ribonucleic acid (dsRNA) induces EC adhesion protein expression and leukocyte adhesion in vitro. Interferon-gamma (IFN-gamma) has been demonstrated to modulate the expression of certain adhesion proteins. The purpose of this study was to measure the inflammatory response to a viral mimetic--a synthetic dsRNA, polyinosinic-polycytidylic acid (poly-I:C)-on the microcirculation of a muscle flap in a rat model and to determine whether IFN-gamma attenuated the response. Two-stage surgery to create a cremaster muscle end-organ tube flap was performed on 18 male Sprague-Dawley rats in three groups. After intra-arterial injection into the abdominal aorta, the reagents (phosphate-buffered saline-bovine serum albumin [PBS-BSA] in groups I and II, and IFN-gamma in group III) were kept for 1 hour in this end-organ system. During the second stage at 16 hours, after injection into the penile vein (PBS-BSA in group I, poly-I:C in groups II and III), the flap was prepared for intravital microscopic measurement. The following parameters were measured: red blood cell velocity; vessel diameter; number of functional capillaries; and number of rolling, sticking, and transmigrating neutrophils and lymphocytes. Wilcoxon's rank sum test was used for statistical comparison. Poly-I:C caused a 70% increase in the main artery diameter and a 7% increase in velocity. But as a consequence of dynamic activation of leukocyte interaction, a 30% drop in functional capillary perfusion was observed. Injury to the entire vascular endothelium was confirmed by a 160% increase in transmigrating leukocytes. Treatment with IFN-gamma inhibited the poly-I:C-induced inflammation, as shown by 88%, 63%, and 85% decreases in rolling, sticking, and transmigrating leukocytes respectively, and by a 28% increase in capillary perfusion. Treating the system with IFN-gamma in advance, inhibited poly-I:C-induced inflammation, shown by marked decreases in rolling, adhering, and transmigrating leukocytes, and a notable increase in perfused capillaries. These observations reflect an inhibitory effect of IFN-gamma on leukocyte adhesion molecule expression in vascular endothelium in response to dsRNA in a muscle flap at the microcirculatory level.

Animals↗

Blockade of platelet endothelial cell adhesion molecule-1 (PECAM-1) protects against ischemia-reperfusion injury in muscle flaps at microcirculatory level.

Several lines of evidence show that platelet endothelial cell adhesion molecule-1 (PECAM-1), a component of endothelial cell junctions, is required for leukocyte transmigration through endothelial cell monolayers. Polymorphonuclear leukocytes play an important role in ischemia-reperfusion injury. We sought to determine whether administering an anti-PECAM-1 antibody would prevent or attenuate ischemia-reperfusion injury in a rat cremaster muscle flap injury model. Eighteen male Sprague-Dawley rats were divided into three groups. Group I (control): Cremaster muscle island flaps were dissected for baseline measurements of eight indicators: numbers of rolling, sticking, and transmigrating neutrophils, numbers of rolling and sticking lymphocytes, number of perfused capillaries, endothelial edema, and vessel permeability. Group II: The prepared cremaster flap was subjected to 4 hours of ischemia and 24 hours of reperfusion. Group III: The muscle flap was subjected to ischemia and reperfusion as in group II, and anti-PECAM-1 antibodies (1 mg/kg) were injected subcutaneously 15 minutes before reperfusion. Blood vessels were observed in vivo under an intravital microscopy system. Microvascular permeability was made visible with injected fluorescein isothiocyanate-labeled albumin and evaluated with Kontron Elektronik computer software. The ischemia-reperfusion-alone group (group II) presented a 225-percent increase in the activation of sticking leukocytes (2.4 +/- 0.4 to 7.8 +/- 0.8, p < 0.05) (p < 0.01). This leukocyte activation was reduced by 83 percent following anti-PECAM-1 monoclonal antibody treatment (1.3 +/- 0.5 per 100 microm) (p < 0.01). At 24 hours, endothelial injury in group II was confirmed by a 4-fold increase in the number of transmigrating leukocytes into the interstitial space (7.6 +/- 1.2 per field versus 1.9 +/- 0.4 per field in controls). This phenomenon was reduced by 85 percent following anti-PECAM-1 monoclonal antibody treatment (1.1 +/- 0.2 per field) (p < 0.01). Analysis showed that the number of flowing capillaries was 67 percent lower in group II (6.8 +/- 0.3 to 2.2 +/- 0.7, p < 0.01). Anti-PECAM-1 antibody treatment caused a 2.5-fold increase in this number (5.6 +/- 0.5, p < 0.01). Microcirculatory permeability index showed a 180-percent increase in group II (p < 0.05) when compared with baseline values. This increased albumin leakage was effectively attenuated by antibody treatment (p < 0.05). Blocking the action of PECAM-1 in vivo by administering monoclonal antibodies significantly attenuated ischemia-reperfusion injury, presumably by inhibiting transendothelial migration of neutrophils and by increasing capillary perfusion at a muscle flap microcirculatory level.

Animals↗

Three-dimensional reconstruction of types IV and V midfacial defects by free rectus abdominis myocutaneous (RAM) flap.

Extensive midfacial defects after ablative surgery constitutes a challenging problem for reconstructive surgeons. Particularly for types IV and V midfacial defects, provision of missing bony support and obliteration of the maxillary cavity defects require microsurgical free tissue transfers. In the last three years, four patients have undergone total maxillectomy for midfacial tumours and the postmaxillectomy defects were three-dimensionally repaired with free rectus abdominis muscle flap and skin graft or myocutaneous flaps. Obliteration of maxillary cavity defects and orbital support were achieved with this type of free flap. The least follow-up period of the patients is one year and slight ectropion, later corrected, was seen in two patients. In this study, the free rectus abdominis myocutaneous (RAM) flap, with its long vascular pedicle and availability of various skin paddle designs and muscle bulk, is presented in treatment of extensive midfacial defects. In spite of initial overcorrection of contour, the denervated rectus abdominis muscle gradually atrophies, resulting in loss of contour. The muscle bulk fills the cavity defect, but, in order to achieve good facial contour, it is necessary to support the bony skeleton with some material.

Abdominal Muscles↗

Reconstruction of foot defects due to mine explosion using muscle flaps.

Landmine explosions bring a formidable challenge to both patients and reconstructive surgeons. Free tissue transfer is the only method of repairing such extensive soft tissue defects of the foot after serial debridements. Sixty-five consecutive free muscle flap transfers were performed in 54 patients who had foot defects involving soft tissue and bone due to mine explosions. Although posttraumatic vessel disease had complicated most of the cases, overall flap survival rate was 83%. Each patient was ambulatory. Ulceration in long-term period was seen in only one patient. Eighty-five percent of patients with successful bone reconstruction and 41.6% of patients without adequate bone replacement demonstrated normal weightbearing in footprints and gait analysis. Free muscle flaps with split thickness skin graft and bone replacement are recommended for the reconstruction of such devastating wounds.

Adult↗

An extraordinary cause of scalding injury in childhood.

In an attempt to statistically evaluate burn injuries in childhood in terms of incidence, aetiology, mortality and morbidity, a surprising aetiological cause was noticed, not only as having a high mortality rate, but also as being preventable in most cases if simple precautions are taken. Fifteen preschool children had been severely scalded in kitchens by hot milk which was heated in a cauldron to produce cheese, a traditional custom. The clinical data relating to this aetiology and the probable underlying factors pertaining to the social characteristics are given and discussed.

Accidents, Home↗

Burn scar carcinoma with longer lag period arising in previously grafted area.

A case of Marjolin's ulcer that arose in previously grafted area of right ankle 55 years after initial burn injury was managed by below knee amputation and right inguinal lymph node dissection. The characteristics of this malignancy were reviewed, and rarely seen features particular to this case, which are a longer lag period and rapid growth in a previously grafted area, were discussed.

Amputation, Surgical↗

Sunflower oil in the treatment of hot tar burns.

Hot tar burns compose a unique class of thermal injury, because removal of this highly sticky compound may be very difficult without inflicting additional tissue damage. Early removal of tar facilitates assessment of the burn and improves patient comfort. Although the use of many substances for the painless removal of tar has been described, we used sunflower oil effectively in the treatment of four tar burn patients. This first report describes the practical and successful use of sunflower oil which was easily obtained from the hospital kitchen.

Accidents, Occupational↗

An unusual case of lightning strike: full-thickness burns of the cranial bones.

An unusual full-thickness burn of the scalp and cranial bones due to a lightning strike is reported. A thick nylon cover protected the head from the direct effects of the lightning injury, but heated water over the thick nylon cover caused full-thickness burn of the scalp and cranial bones. The relevant literature has been reviewed.

Adult↗

Reconstruction of saddle nose deformities using porous polyethylene implant.

Various materials have been employed for nasal contour restoration. We used porous polyethylene implants in reconstruction of saddle nose deformity in 36 cases. Only one complication occurred in the 8-18 months follow-up period. No implant was removed. Both cosmetic and functional results were accepted as pleasing by the patients.

Adult↗

The last 10 years in a burn centre in Ankara, Turkey: an analysis of 5264 cases.

This is a retrospective study analysing 5264 patients treated in the burn centre at Gülhane Military Medical Academy from 1 January 1986 to 31 December 1995. Our burn centre is not only the first, but one of the best established and supported in Turkey. Our present study has the largest patient group of other previously published studies from Turkey. Of the total patients studied, 4464 patients had minor burns and were treated on an outpatient basis and 800 patients had moderate to major burns. Although our centre is in a military area in Ankara, only 1047 (20 per cent) patients were military personnel and the military-related burn causes comprised only 6 per cent of the total. The remaining 4217 (80 per cent of the total patients) were civilians. Flame injuries were also more frequent in military patients than civilians. Minor burns were most common in the age group 0-10 years old (40 per cent) and moderate to major burns in the age group 21-30 years (54 per cent). Scalds were the main cause of paediatric burns. Male patients were dominant. The overall mortality among inpatients was 18.2 per cent and mean total body surface area (TBSA) was 57.6 per cent in patients who died. 134 patients demonstrated inhalation injury and 82 per cent of these patients died. The epidemiological pattern of our patients is similar to that in other studies from developed countries, although some ethnic causative factors could be found. Our study indicates that emergency measures should be taken to prevent flame injuries at military barracks and industrial workplaces and scalding accidents to children at home and throughout the country.

Adolescent↗

An unusual cause of burn injury: unsupervised use of drugs that contain psoralens.

Although psoralens are useful components of the psoralen ultraviolet A-range therapy that is mainly used for the treatment of vitiligo, psoriasis, and hypopigmented scars, they have a narrow margin of safety. Oral and topical forms of psoralen-containing drugs are routinely used in medicine. Because psoralens sensitize skin to ultraviolet A light, phototoxic reactions are the most frequent adverse effect of this treatment. Sunburn may sometimes be a major injury in psoralen users because high doses or inappropriate use of the drug may render the skin extremely sensitive. In this article, we present the case of a vitiligo patient who was admitted to our facility with an intense burn after the topical use of 8-methoxypsoralen solution as a suntanning agent. We will also discuss the unusual nature of this type of burn and the course of phototoxic lesions and their differences from a typical sunburn.

Administration, Topical↗