Retinal ischemia following mandible tumor treatment with steroid injection / Isquemia de retina após tratamento de tumor de mandíbula com injeção de esteroide

ABSTRACT Central giant cell granuloma is a rare osseous tumor affecting young patients with anatomical and functional compromise of the maxilla and mandible. Steroid injection therapy constitutes a less invasive treatment modality for disease control in selected cases. Retinal ischemia is a reported complication of multiple medical procedures, including dental interventions, and may lead to loss of vision with poor prognosis. We report a case of retinal arteriolar ischemic disease following central giant cell granuloma management with local injected corticosteroids.

RESUMO O granuloma central de células gigantes é um tumor ósseo raro que afeta pacientes jovens com comprometimento anatômico e funcional da maxila e mandíbula. A terapia com injeção de esteroides constitui uma modalidade de tratamento menos invasiva para o controle da doença em casos selecionados. A isquemia retiniana é uma complicação relatada em vários procedimentos médicos, incluindo intervenções odontológicas, e pode levar à perda da visão com mau prognóstico. Relatamos um caso de doença isquêmica arteriolar da retina após o tratamento com granuloma central de células gigantes com corticosteroides injetados locais.

Distorsión morfológica isquémica de la onda T en la centellografía de perfusión miocárdica con estrés vasodilatador / Ischemic T wave distortion associated with vasodilator-stress myocardial perfusion imaging

Los protocolos que utilizan vasodilatadores para inducir isquemia en la centellografía de perfusión miocárdica han demostrado una exactitud diagnóstica elevada e incidencia muy baja de complicaciones graves. Sin embargo, el significado fisiológico y valor diagnóstico de diversas alteraciones electrocardiográficas asociadas al estrés vasodilatador ha sido escasamente evaluado más allá del segmento ST. Describimos cinco pacientes que presentan distorsión morfológica de la onda T en derivaciones electrocardiográficas torácicas asociada a diversos defectos de perfusión, discutiendo los potenciales aportes de estos cambios al diagnóstico y cuantificación de la isquemia miocárdica en los estudios de imagen que utilizan estrés con vasodilatadores.

The protocols using vasodilators to induce ischemia on myocardial perfusion scintigraphy have shown a high diagnostic accuracy and a very low incidence of serious complications. However, the physiological significance and diagnostic value of various electrocardiographic changes associated with vasodilator stress has not been deeply evaluated beyond the ST-segment. Five clinical cases presenting morphological distortion of the T-wave in electrocardiographic chest leads associated with varying degrees of perfusion defects are described, discussing potential contributions of these changes to the diagnosis and quantification of myocardial ischemia in imaging studies using vasodilator stress.

Acute hyperglycemia prevents dexmedetomidine-induced preconditioning against renal ischemia-reperfusion injury

PURPOSE: To investigate the effects of acute hyperglycemia on dexmedetomidine-induced preconditioning against renal ischemia-reperfusion injury. METHODS: Sprague-Dawley rats were randomly arranged to the normoglycemic (NG) or hyperglycemic group (HG), with each group further divided into sham (no I/R injury), I/R (ischemia-reperfusion) and dex (given by dexmedetomidine) groups. Acute hyperglycemia was induced by intraperitoneal injection (i.p.) of 25% glucose (3 g/kg) 45 min before ischemia. Dexmedetomidine (50 μg/kg, i.p.) was administrated 30 min before induction of ischemia. Renal function, histology, apoptosis, expression of Bax, Bcl-2 and phosphorylated AKT (p-AKT) were detected. RESULTS: I/R insult significantly increased the serum levels of blood urea nitrogen and creatinine, apoptotic tubular epithelial cells, expression of Bax and p-AKT, but decreased Bcl-2 expression. All these changes were further enhanced by hyperglycemia (p<0.05). In hyperglycemic condition, there was no statistically difference between the I/R group and Dex group in all the aforementioned detection indexes (p>0.05). CONCLUSION: Acute hyperglycemia attenuates dexmedetomidine-induced preconditioning against renal ischemia-reperfusion injury in non-diabetic rats. .

Phenylephrine postconditioning increases myocardial injury: Are alpha-1 sympathomimetic agonist cardioprotective.

Objective: We studied effects of phenylephrine (PHE) on postischemic functional recovery and myocardial injury in an ischemia-reperfusion (I-R) experimental model. Materials and Methods: Rat hearts were Langendorff-perfused and subjected to 30 min zero-fl ow ischemia (I) and 60 min reperfusion (R). During R PHE was added at doses of 1 μM (n = 10) and 50 μM (n = 12). Hearts (n = 14) subjected to 30 and 60 min of I-R served as controls. Contractile function was assessed by left ventricular developed pressure (LVDP) and the rate of increase and decrease of LVDP; apoptosis by fl uorescent imaging targeting activated caspase-3, while myocardial injury by lactate dehydrogenase (LDH) released during R. Activation of kinases was measured at 5, 15, and 60 min of R using western blotting. Results: PHE did not improve postischemic contractile function. PHE increased LDH release (IU/g); 102 ± 10.4 (Mean ± standard error of mean) control versus 148 ± 14.8 PHE (1), and 145.3 ± 11 PHE (50) hearts, (P < 0.05). PHE markedly increased apoptosis. Molecular analysis showed no effect of PHE on the activation of proapoptotic c-Jun N-terminal kinase signaling; a differential pattern of p38 mitogen activated protein kinase (MAPK) activation was found depending on the PHE dose used. With 1 μM PHE, p-p38/total-p38 MAPK levels at R were markedly increased, indicating its detrimental effect. With PHE 50 μM, no further changes in p38 MAPK were seen. Activation of Akt kinase was decreased implying involvement of different mechanisms in this response. Conclusions: PHE administration during reperfusion does not improve postischemic recovery due to exacerbation of myocardial necrosis and apoptosis. This fi nding may be of clinical and therapeutic relevance.

Rat Model of Hindlimb Ischemia Induced via Embolization with Polyvinyl Alcohol and N-Butyl Cyanoacrylate

OBJECTIVE: To investigate the feasibility of a rat model on hindlimb ischemia induced by embolization from the administration of polyvinyl alcohol (PVA) particles or N-butyl cyanoacrylate (NBCA). MATERIALS AND METHODS: Unilateral hindlimb ischemia was induced by embolization with NBCA (n = 4), PVA (n = 4) or surgical excision (n = 4) in a total of 12 Sprague-Dawley rats. On days 0, 7 and 14, the time-of-flight magnetic resonance angiography (TOF-MRA) and enhanced MRI were obtained as scheduled by using a 3T-MR scanner. The clinical ischemic index, volume change and degree of muscle necrosis observed on the enhanced MRI in the ischemic hindlimb were being compared among three groups using the analysis of variance. Vascular patency on TOF-MRA was evaluated and correlated with angiographic findings when using an inter-rater agreement test. RESULTS: There was a technical success rate of 100% for both the embolization and surgery groups. The clinical ischemic index did not significantly differ. On day 7, the ratios of the muscular infarctions were 0.436, 0.173 and 0 at thigh levels and 0.503, 0.337 and 0 at calf levels for the NBCA, PVA and surgery groups, respectively. In addition, the embolization group presented increased volume and then decreased volume on days 7 and 14, respectively. The surgery group presented a gradual volume decrease. Good correlation was shown between the TOF-MRA and angiographic findings (kappa value of 0.795). CONCLUSION: The examined hindlimb ischemia model using embolization with NBCA and PVA particles in rats is a feasible model for further research, and muscle necrosis was evident as compared with the surgical model.

The protective effect of cilostazol on isolated rabbit femoral arteries under conditions of ischemia and reperfusion: the role of the nitric oxide pathway

OBJECTIVES: The clinical significance of ischemia/reperfusion of the lower extremities demands further investigation to enable the development of more effective therapeutic alternatives. This study investigated the changes in the vascular reactivity of the rabbit femoral artery and nitric oxide metabolites under partial ischemia/ reperfusion conditions following cilostazol administration. METHODS: Ischemia was induced using infrarenal aortic clamping. The animals were randomly divided into seven groups: Control 90 minutes, Ischemia/Reperfusion 90/60 minutes, Control 120 minutes, Ischemia/Reperfusion 120/90 minutes, Cilostazol, Cilostazol before Ischemia/Reperfusion 120/90 minutes, and Ischemia 120 minutes/Cilostazol/ Reperfusion 90 minutes. Dose-response curves for sodium nitroprusside, acetylcholine, and the calcium ionophore A23187 were obtained in isolated femoral arteries. The levels of nitrites and nitrates in the plasma and skeletal muscle were determined using chemiluminescence. RESULTS: Acetylcholine-and A23187-induced relaxation was reduced in the Ischemia/Reperfusion 120/90 group, and treatment with cilostazol partially prevented this ischemia/reperfusion-induced endothelium impairment. Only cilostazol treatment increased plasma levels of nitrites and nitrates. An elevation in the levels of nitrites and nitrates was observed in muscle tissues in the Ischemia/Reperfusion 120/90, Cilostazol/Ischemia/Reperfusion, and Ischemia/ Cilostazol/Reperfusion groups. CONCLUSION: Hind limb ischemia/reperfusion yielded an impaired endothelium-dependent relaxation of the femoral artery. Furthermore, cilostazol administration prior to ischemia exerted a protective effect on endotheliumdependent vascular reactivity under ischemia/reperfusion conditions.

Aspectos morfológicos, morfométricos e ultraestruturais do baço de ratos após o clampeamento total do pedículo hepático / Morphologic, morphometric, and ultrastructural aspects of the spleen of rats after hepatic pedicle total clamping

Avaliaram-se as alterações morfológicas, morfométricas e ultraestruturais que ocorreram no baço devido à isquemia produzida pelo clampeamento total do pedículo hepático. Para tanto, foram utilizados 40 ratos machos, distribuídos em quatro grupos de 10 animais. O grupo-controle (C) não foi submetido à isquemia, e os grupos tratados (E1, E2e E3) foram submetidos ao clampeamento por 10, 20 e 30 minutos, respectivamente. Fragmentos do baço foram retirados e analisados histologicamente pela microscopia de luz (hematoxilina-eosina, ferrocianeto-férrico) e pela microscopia eletrônica de transmissão. Os resultados demonstraram que 10 minutos de clampeamento do pedículo hepático são suficientes para apresentar sinais de congestão esplênica e 20 e 30 minutos promovem intensa digestão de hemácias pelos macrófagos, com presença de grânulos de ferro (hemossiderina) no parênquima esplênico.

The macro and microscopic alterations that occurred in the spleen during an ischemia produced by the hepatic pedicle total clamping were studied. Forty male rats were distributed in four groups of 10 animals each. The control group (C) was not submitted to ischemia and the treated groups (E1, E2, and E3) were submitted to the clamping during 10, 20, and 30 minutes, respectively. Spleen fragments were collected and histologically analyzed by the light microscopy (eosin-hematoxilin and ferric ferrocyanide) and by the transmission electron microscopy. The results showed that 10 minutes of hepatic pedicle total clamping was enough produce signs of splenic congestion and 20 and 30 minutes promoted intense red bood cels digestion by the macrophages with the presence of iron granules (hemosiderin) in the splenic parenchyma.

Oclusão arterial aguda por derivados da ergotamina / Acute arterial occlusion caused by ergotamine derivatives

Os derivados da ergotamina compõem diversas drogas amplamente utilizadas no tratamento de ataques agudos de migrânea. A intoxicação por estas substâncias resulta geralmente de sua administração crônica, promovendo sintomas secundários ao espasmo arterial e à consequente isquemia distal. Neste artigo, é relatado o caso de uma paciente de 47 anos com diagnóstico de oclusão arterial aguda em membros inferiores secundária ao uso de derivados da ergotamina. Após a suspensão da droga e a prescrição de anticoagulantes, vasodilatadores e antiagregante plaquetário, a paciente evoluiu com melhora da dor, da parestesia e com o retorno da coloração normal e dos pulsos distais em membros inferiores.

Ergotamine derivatives include several drugs widely used in the treatment of acute migraine attacks. Intoxication by these substances generally results from chronic administration, promoting symptoms secondary to arterial spasm and the consequent distal ischemia. The authors report the case of a 47-year old patient with acute arterial occlusion in lower limbs secondary to the use of ergotamine derivatives. After drugs were suspended and anticoagulants, vasodilators and antiplatelet drugs were prescribed, the patient progressed with improvement of pain, paresthesia and return of normal skin color and distal pulses in lower limbs.

Tobacco smoking and surgical healing of oral tissues: a review.

It is believed that the crew of Columbus had introduced tobacco from the 'American India' to the rest of the world, and tobacco was attributed as a medicinal plant. It was often used to avert hunger during long hours of work. But in reality, tobacco causes various ill effects including pre-malignant lesions and cancers. This article aims at reviewing the literature pertaining to the effect of tobacco smoking upon the outcome of various surgical procedures performed in the oral cavity. Tobacco affects postoperative wound healing following surgical and nonsurgical tooth extractions, routine maxillofacial surgeries, implants, and periodontal therapies. In an experimental study, bone regeneration after distraction osteogenesis was found to be negatively affected by smoking. Thus, tobacco, a peripheral vasoconstrictor, along with its products like nicotine increases platelet adhesiveness, raises the risk of microvascular occlusion, and causes tissue ischemia. Smoking tobacco is also associated with catecholamines release resulting in vasoconstriction and decreased tissue perfusion. Smoking is believed to suppress the innate and host immune responses, affecting the function of neutrophils--the prime line of defense against infection. Thus, the association between smoking and delayed healing of oral tissues following surgeries is evident. Dental surgeons should stress on the ill effects of tobacco upon the routine postoperative healing to smoker patients and should aid them to become tobacco-free.

A Case of Ischemic Skin Necrosis after Glypressin Therapy in Liver Cirrhosis / 대한소화기학회지

Terlipressin is a synthetic analogue of vasopressin, which has been used in the treatment of acute variceal hemorrhage. In contrast to vasopressin, terlipressin can be administered as intermittent injections instead of continuous intravenous infusion. Thus, it has a less adverse reaction than vasopressin. We report a case of ischemic skin complication in a cirrhotic patient treated with terlipressin. A 71-year-old man with liver cirrhosis was admitted because of hematemesis and melena. He was commenced on terlipressin at a dose 1 mg every 6 hours for the treatment of varicieal bleeding. After 36 hours of treatment, skin blistering and ecchymosis was noted on the skin of his upper thigh, scrotal area and trunk. We found that terlipressin was a possible cause of ischemic skin complication based on the skin biopsy finding. Terlipressin may induce a complication of the ischemic event. In spite of rarity, special attention needs to paid on the peripheral ischemic complication of terlipressin.

A Case of Peripheral Ischemic Complication after Terlipressin Therapy / 대한소화기학회지

Hepatorenal syndrome is a severe complication of cirrhosis, leading to death in more than 90% of cases in the absence of liver transplantation. Several treatments have been attempted as a bridge to liver transplantation. Among such treatments, terlipressin is a nonselective V1 vasopressin agonist. When comparing with ornipressin, it is known to have a similar vasoconstricting potency, but much less ischemic complication. We report a case of gangrene on toes and necrosis on the infusion site of left hand which developed after the use of terlipressin due to hepatorenal syndrome in a 41-year-old-man with liver cirrhosis. Ischemic complication of terlipressin is rare and there has been no case report in Korea. Although it is rare, we must pay attention to the peripheral ischemic complication of terlipressin.

Ergotamine-Induced Upper Extremity Ischemia: A Case Report

Ergotamine-induced limb ischemia is an extremely rare case. We present a case of a 64-year-old man, who developed ischemia on the right upper extremity due to long-term use of Ergot for migraine headache. Angiography revealed diffused, smooth, and tapered narrowing of the brachial artery. The patient was successfully treated with intravenous nitroprusside.

Estrogen supplementation failed to attenuate biochemical indices of neutrophil infiltration or damage in rat skeletal muscles following ischemia

This study examined the effects of estrogen supplementation on markers of neutrophil infiltration and damage in skeletal muscle of rats following ischemia. Male and female gonad-intact rats, with or without 14 days of estrogen supplementation were subjected to two hours of hind-limb ischemia and sacrificed at 24, 48 or 72 hours post-ischemia. Control animals were sacrificed without ischemia. Plantaris and red and white gastrocneimus muscles were removed and assayed for myeloperoxidase (MPO), a marker of neutrophil infiltration, and glucose-6-phosphate dehydrogenase (G6PD) and a-glucuronidase (GLU), as markers of muscle damage. Significant elevations of MPO, G6PD and GLU activities were observed at various time points post-ischemia. No systematic differences between genders were noted in any of the measures. Estrogen supplementation in both male and female animals failed to significantly attenuate post-ischemia increases in MPO, G6PD and GLU activities in any of the muscles studied and in some cases accentuated activities of some of these measures. Unlike previous findings following exercise in skeletal muscle, this study failed to demonstrate estrogen-induced attenuation of indices of neutrophil infiltration or damage in skeletal muscles of rats up to 72 hours following ischemia. This demonstrates that estrogen may not consistently attenuate neutrophil infiltration and that a number of variables including damage modality, tissue or estrogen level may influence this.

A antibioticoterapia prévia sobre o infiltrado inflamatório pulmonar após isquemia e reperfusäo intestinal: estudo experimental em ratos / Previous antibiotic therapy on the lung inflamatory infiltrate after ischemia and intestinal reperfusion: experimental study in rats

A isquemia seguida de reperfusão intestinal (I/R) é um evento clínico comum que favorece a translocação bacteriana em órgãos à distância, como os pulmões. A antibioticoterapia prévia pode ser uma conduta eficaz para atenuar o desenvolvimento desse processo. Este esudo tem por finalidade reconhecer a concentração dos polimorfonucleares (PMN) nos septos alveolares em ratos, após indução de isquemia seguida de reperfusão intestinal, com e sem antibioticoterapia prévia. Utilizaram-se 48 ratos divididos, aleatoriamente em 6 grupos (A,B,C,D,E,F)com 8 animais cada um. Os grupos A,C e E não receberam antibiótico,e os grupos B, D e F receberam 500mg/Kg de eritromicina por via oral. Os grupos A e B serviram de controle; C e D induziu-se isquemia intestinaL por 30 min; e os grupos E e F seguiu-se à isquemia, reperfusão por 30 min. Em seguida, abriu-se o tórax e ressecaram-se os pulmões, sendo encaminhados para análise histopatológica e histométrica, obtendo-se uma média de PMN nos septos alvéolos...

Angiogénesis inducida por colágena polivinilpirrolidona y heparina en el músculo isquémico / Angiogenesis induced by polivinilpirrolidone collagen and heparin in the ischemic muscle

Estudio de investigación experimental, prospectivo y comparativo, con el objeto de evaluar los efectos de la aplicación exógena de colágena tipo I, Polivinilpirrolidona (PVP) y heparina, en túneles musculares fibrocolágenos, en la extremidad isquémica de la rata, para inducir neovascularización o angiogénesis. Se usó un modelo de isquemia en la extremidad posterior derecha de 40 ratas Wistar en dos tiempos. 1º Ligadura de la arteria iliaca común vía abdominal y colocación de una protesis de silasticpoliéster en el músculo gracilis para la generación de un túnel fibrocolágeno. 2º Ocho semanas después, exposición del paquete vascular femoral, ligadura de esta arteria, localización y extracción de la prótesis, perforación y lavado del túnel fibrocolágeno y aplicación de sustancias. En el grupo I se aplicó solución fisiológica, en el grupo II colágena tipo I con PVP, en el grupo III heparina sódica y grupo IV colágena tipo I con (PVP) y heparina sódica. Para la valoración se llevó a cabo angiografía de las extremidades tratadas, cuantificando el número de intersecciones en una superficie milimétrica de 50 x 50 mm. El mayor número de intersecciones se obtuvo en el grupo IV con una medida de 20.22 contra una media de 13.5 intersecciones en el grupo I (control con sol. fisiológica) = p de 0.14 mediante el análisis de varianza para comparar dos grupos (ANOVA). El estudio demuestra mayor angiogénesis en el músculo isquemico de la rata, si se aplica colágena tipo I con (PVP) y heparina

Efeitos do alopurinol sobre a lipoperoxidaçäo de membranas celulares renais na síndrome da isquemia e reperfusäo: estudo experimental em ratos / Allopurinol effect in lipid peroxidation of renal cellular membranes in ischemia-reperfusion: experimental study in rats

Vários estudos têm demonstrado que Radicais Livres de Oxigênio (RLO) contribuem para o dano celular decorrente da isquemia e reperfusao. Este estudo foi desenvolvido como o objetivo de avaliar os efeitos da isquemia e reperfusao renal em ratos, tratados ou nao com alopurinol, sobre a lipoperoxidaçao (LPO) das membranas celulares renais. Método: Foram usados ratos Wistar distribuídos em 4 grupos e submetidos a períodos de isquemia e reperfusao renal ou nao, dependendo do grupo. Também foram submetidos ou nao a tratamento com alopurinol na dose de 50 a 150 mg/Kg por via intraperitoneal, 5 e 1 horas antes do procedimento. Na avaliaçao da lipoperoxidaçao utilizou-se os métodos do TBARS e QL. Resultados: Os resultados demonstraram aumento da LPO nos animais submetidos a isquemia e reperfusao renal. No entanto, estes efeitos deletérios foram reduzidos com o pré-tratamento com alopurinol (p<0,05). Conclusao: O dano causado em animais submetidos a isquemia e reperfusao renal pode ser demonstrado e quantificado pela LPO. Além disso, o alopurinol demonstrou proteçao renal contra o dano decorrente desta síndrome, diminuindo a LPO nestes animais. Estes resultados sugerem que a via da xantina oxidase é uma das mais importantes rotas metabólicas envolvidas na geraçao de RLO, estes responsáveis em parte pelos danos funcionais do rim na síndrome da isquemia e reperfusao deste órgao.

Isquemia aguda de la mano secundaria a la admmnistración intraarterial de cloxacilina / Hand acute ischemia secondary to the intraarterial administration of cloxaciline

La isquemia aguda de la mano, luego de la inyección intraarterial de medicamentoses un problema frecuente, de difícil manejo, y que requiere tratamiento médico urgente. Este reporte describe un caso de inyección inadvertido de cloxacilina en arteria humeral, con isquemia grave de mano, que llegó a la amputación digital. Se discute patogénesis y opciones de tratamiento

Lipoperoxidaçäo das membranas celulares dos hepatócitos causada pela formaçäo de radicais livres em fígados submetidos à isquemia-reperfusäo: modelo experimental em ratos / Lipid proxidation of hepatocycle cells membrane caused by free radicals formation livers submitted to ischemia-reperfusion: experimental model in rats

Os radicais livres de oxigênio (RLO) formados durante o processo de isquemia-reperfusäo tecidual estäo envolvidos em processos que ocasionam dano celular. O objetivo deste estudo foi comprovar se a lipoperoxidaçäo (LPO) induzida por RLO está associada ao dano celular provocado pela isquemia-reperfusäo tecidual. Foram utilizados ratos Wistar divididos em 2 grupos: Grupo 1 (controle) e Grupo 2 (isquemia hepática durante 1 h seguida de 1 h de reperfusäo). A lipoperoxidaçäo foi avaliada através dos métodos de substâncias reativas ao ácido tiobarbitúrico (TBARS) e quimiluminescência iniciada por hidroperóxido de tert-butil (QL). Demonstrou-se uma diferença estatística significativa entre os grupos (p< 0,05) com valores maiores de LPO para o Grupo 2. Diante dos dados, podemos concluir que o processo de isquemia-reperfusäo ocasiona aumento na LPO, sendo um indicativo de dano celular. Assim, este modelo é passível de ser utilizado para verificar o benefício do uso de agentes farmacológicos que visem diminuir o dano tecidual em cirurgias que necessitam este tipo de procedimento