Bekir Hakan Bakkal

Effects of ozone oxidative preconditioning on radiation-induced organ damage in rats

Because radiation-induced cellular damage is attributed primarily to harmful effects of free radicals, molecules with direct free radical scavenging properties are particularly promising as radioprotectors. It has been demonstrated that controlled ozone administration may promote an adaptation to oxidative stress, preventing the damage induced by reactive oxygen species. Thus, we hypothesized that ozone would ameliorate oxidative damage caused by total body irradiation (TBI) with a single dose of 6 Gy in rat liver and ileum tissues. Rats were randomly divided into groups as follows: control group; saline-treated and irradiated (IR) groups; and ozone oxidative preconditioning (OOP) and IR groups. Animals were exposed to TBI after a 5-day intraperitoneal pretreatment with either saline or ozone (1 mg/kg/day). They were decapitated at either 6 h or 72 h after TBI. Plasma, liver and ileum samples were obtained. Serum AST, ALT and TNF-α levels were elevated in the IR groups compared with the control group and were decreased after treatment with OOP. TBI resulted in a significant increase in the levels of MDA in the liver and ileal tissues and a decrease of SOD activities. The results demonstrated that the levels of MDA liver and ileal tissues in irradiated rats that were pretreated with ozone were significantly decreased, while SOD activities were significantly increased. OOP reversed all histopathological alterations induced by irradiation. In conclusion, data obtained from this study indicated that ozone could increase the endogenous antioxidant defense mechanism in rats and there by protect the animals from radiation-induced organ toxicity.

Protection by L-carnitine against radiation-induced ileal mucosal injury in the rat: Pattern of oxidative stress, apoptosis and cytokines

Abstract Purpose: In this study, we tested the effects of L-carnitine (LC) on radiation-induced ileal mucosal damage. Materials and methods: Thirty Wistar albino rats were divided into five groups. The control group received physiological saline intraperitoneally (i.p.). Radiation-1 and radiation-2 groups received whole-body X-irradiation of 8.3 Gy as a single dose. These groups were sacrificed at the 6th hour and 4th day after irradiation, respectively. The Radiation-1 + LC and the radiation-2 + LC groups received the same dose irradiation plus a daily dose of 200 mg/kg LC. LC was applied one day before and for four days after irradiation. Results: The levels of serum monocyte chemotactic protein-1 (MCP-1) and interferon gamma (IFN-γ) were significantly higher in the radiation groups when compared with the control. Treatment with LC decreased the serum MCP-1 and IFN-γ levels considerably. In the radiations groups, the Chiu score was significantly elevated compared with that of the control group. However, LC administered prior to the irradiation reduced the severity of mucosal damage. The number of apoptotic cells of the ileal crypt in the irradiated rats increased from the 6th hour after irradiation and then decreased at 4th day. Conclusions: Our data demonstrated that LC may be beneficial to radiation enteritis.

Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats.

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

Effects of Ozonated Olive Oil on Acute Radiation Proctitis in Rats

BACKGROUND Acute radiation proctitis is a common complication of pelvic radiation and management of acute radiation proctitis is under evaluation. The beneficial effects of ozonated olive oil (OzOO) have already been shown in the treatment of chronic wounds. Thus, this study was designed to evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. AIMS To evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. STUDY DESIGN Animal experimentation. METHODS RATS WERE DIVIDED INTO THREE GROUPS: control; irradiation+saline (1 mL); and irradiation +OzOO (1 mL). A single fraction of 17.5 Gy was delivered to each rat. The OzOO was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanised on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically. RESULTS According to the clinical findings, five rats in the irradiation+saline group showed Grade 4 symptoms on the 10(th) day. Macroscopic finding scores on the 10(th) day in the irradiation+saline and irradiation+OzOO groups were statistically significantly different. On pathological examination, radiation-induced mucosal damage was the most prominent 10 days after irradiation in saline-treated rats. On the 10(th) day, the irradiation+OzOO group showed mild inflammation and slight crypt change, which corresponded to Grade 1 pathological findings. CONCLUSION OzOO attenuates macroscopic and pathological findings of acute radiation proctitis in rats.

Effect of treatment position and radiotherapy planning on testicular dose in patients with rectal carcinoma

AIMS The aim of this study was to evaluate and compare the effect of radiotherapy on testicles with different treatment positions and plans for rectal cancer patients. SETTINGS AND DESIGN Mono-institutional prospective study. PATIENTS AND METHODS Three different plans; supine 4-fields (s4f), prone 4-fields (p4f), and prone 3-fields (p3f) of 15 male patients with rectal carcinoma receiving 45 Gy pelvic radiotherapy were evaluated. Testicular doses in each plan were calculated. Since the localizations of the primary tumor may affect testicular dose, boost doses were not taken into account. STATISTICAL ANALYSIS USED Kruskal Wallis test, Pearson and Spearman correlation analysis. RESULTS Median cumulative testicular doses of s4f, p4f, and p3f plans were 19.8, 69.3, and 100.8 cGy, respectively (P = 0.013). Median V0.5 (Volume receiving more than 0.5 Gy) and V1 (Volume receiving more than 1 Gy) for testicles were also significantly lower in s4f plans (3%, 60.7%, and 78.1% for V0.5 and 0.3%, 35.8%, and 52.3% for V1 in s4f, p4f, and p3f, respectively) (P = 0.001). The median distances between lower edge of fields and testicles in s4f, p4f, and p3f plans were 65 mm, 29 mm, and 29 mm, respectively (P < 0.01). Median bladder doses were significantly lower in p3f plans (P = 0.002). CONCLUSIONS S4f external beam radiotherapy for rectal carcinoma allows better testicular dose than p3f and p4f. The probably reason was the increase of distance between lower edge of the field and testicles.

Chronic Pelvic Abscedation After Completion Proctectomy in a Rectal Stump Insufficiency; Treatment With Gracilis Muscle Flap Following Vacuum Assisted Closure Therapy

Presacral abscess formation due to rectal stump insufficiency following Hartmann procedure is very rare complication. If the abscess cavity is large, it might delay the reversal of the stoma and will probably result in a devastating future functioning of the neorectum. Moreover, very invasive treatments will be required in order to prevent severe septic complications. We present the case of a 58-year-old man with a past history of Hartmann procedure for a low rectal carcinoma who presented with rectal stump insufficiency and a large presacral abscess. Following extensive debridement and rectal stump resection, a vacuum-assisted closure (VAC) system was applied to the large abscess cavity to facilitate gracilis muscle flap reconstruction and to optimize wound healing. The satisfactory results showed in the present report led us to favor a combination of VAC therapy and a gracilis muscle flap in intrapelvic and perineal reconstruction in the case of large defects associated with high risks of septic complications.

İyonize Radyasyona Maruz Kalmış Sıçan Ovaryumunda Gelişmekte Olan Foliküllerde Morfolojik Değişiklikler Üzerine L-karnitinin Koruyucu Etkisi

AMAC: Radyasyon hucrelerin cekirdek ve sitoplazmasinda bir takim degisikliklere sebebiyet verebilir, memeli germ hucreleri de iyonize radyasyona (IR) karsi oldukca duyarlidir. Iyonize radyasyon ovaryum follikullerindeki dejenerasyonu arttirir. Bu calismanin amaci tum vucudu iyonize radyasyona maruz kalan sicanlarin ovaryum follikullerinde L-karnitinin (LK) antiapoptotik ve radyoprotektif etkilerini arastirmaktir. MATERYAL-METOD: Calismamizda 30 adet Wistar albino disi sican 5 ayri gruba ayrildi. Radyasyon hasari icin kontrol haric tum sicanlara 8,3 Gy X isini uygulandi. LK gruplarina isinlamadan once gunluk 200mg/kg LK uygulandi. Isinlama sonrasi 6.saatte (Rad-1) ve 4. gunde (Rad-2) ovaryum dokulari toplandi. Ovaryum dokusundan her 5. kesit alinarak hematoksilen-eozin boyamasi yapilarak oosit cekirdeginin goruldugu her oosit sayildi. Follikuller primordiyal, primer, preantral ve antral olacak sekilde siniflandirildi. Serumdaki IL-1α (interlokin-1 alfa), IL-4 (interlokin-4) ve GM-CSF (granulosit monosit koloni situmulan faktor) degerleri flow sitometri ile analiz edildi. BULGULAR : Iyonize radyasyon uygulamasinin sonrasinda 6.saat ve 4. gun ovaryum dokulari alinan gruplarda atretik follikullerin oraninda artis gozlendi. Granuloza hucreleri yuvarlak sekilli ve apoptotik hucre gorunumunde izlendi. Iyonize radyasyona maruz kalan sicanlarin ovaryum dokulari incelendiginde 4.gun IR grubunda atretik follikullerin sayisi 6. saat IR grubuna gore belirgin bir sekilde artmisti. LK uygulanan gruplarda IR’nun yarattigi hasarda belirgin bir duzelme gozlendi. IR gruplarinda serumdaki IL-1α, IL-4 ve GM-CSF duzeyleri kontrol grubu ve tedavi grubuna gore artmis olarak izlendi. SONUC : Iyonize radyasyonun akut olarak primordiyal ve primer follikullerdeki dejenerasyonu arttirdigi sonucuna varilmistir. Ayrica, L-karnitinin iyonize radyasyona bagli gelisen follikuler atrezide koruyucu bir rolu oldugunu dusunmekteyiz.

Filgrastim helps to heal herpes zoster faster: two case reports

Herpes zoster is an infectious disease caused by varicella-zoster virus that may occur sporadically at any age. We report on two patients with herpes zoster who received chemotherapy for breast cancer. Both patients were immunocompromised and received filgrastim therapy for the management of neutropenia. Zoster occurred during filgrastim therapy but the symptoms were alleviated rapidly in the course of therapy. We conclude that granulocyte colony-stimulating factor therapy helped symptom alleviation and accelerated the recovery from herpes zoster in our chemotherapy-treated patients. Free full text available at www.tumorionline.it