BACKGROUNDThe protective effects of transient limb ischemia (TLI) induced by several cycles of intermittent pressure cuff inflation and deflation for a period have been widely investigated, however the reliability of this protocol has not been clearly verified. Our study aimed to investigate the reliability of pressure cuff induced TLI in conscious rabbits.

METHODSEight New Zealand rabbits were subjected to TLI without anesthesia. TLI consisted of 3 cycles of ischemia and reperfusion induced by inflating the cuff placed on the left lower limb to 200 mmHg for 5 minutes followed by deflating the cuff for 5 minutes. Skin color, pulse oxygen saturation (SpO2), pulse rate (PR), plethysmogram waveform (Pleth), and ultrasound detection of the blood flow in the extremity distal to the ischemic segment were observed to confirm ischemia and reperfusion during TLI. The frequency of severe limb movement during TLI was also recorded to assess the amenability of this protocol in conscious rabbits.

RESULTSThe skin color of the extremity distal to the ischemic segment changed from bright red to dark purple after inflating the cuff to 200 mmHg, and returned to normal after cuff deflation. Pleth, PR and SpO2 disappeared during ischemia and restored during reperfusion in the monitor. Blood flow of the left posterior tibial artery was completely blocked by a pressure of 200 mmHg during ischemia, and recovered immediately after cuff deflation. The frequency of severe limb movement in supine position was higher than that in prone position (P < 0.05), but there was no severe limb movement that could result in disturbance to ischemia when the rabbits were placed in prone position.

CONCLUSIONPressure cuff inflating to 200 mmHg for 5 minutes and deflating for 5 minutes is a reliable regimen to induce TLI in conscious rabbits.

Animals ; Disease Models, Animal ; Extremities ; pathology ; Ischemia ; etiology ; pathology ; Ischemic Preconditioning ; Male ; Rabbits

Burns ; complications ; pathology ; physiopathology ; Humans ; Mitochondria, Heart ; pathology ; Myocardial Ischemia ; etiology ; prevention & control

This study evaluated the application of quantitative tissue velocity imaging (QTVI) in assessing regional myocardial systolic and diastolic functions in dogs with acute subendocardial ischemia. Animal models of subendocardial ischemia were established by injecting microspheres (about 300 microm in diameter) into the proximal end of left circumflex coronary artery in 11 hybrid dogs through cannulation. Before and after embolization, two-dimensional echocardiography, QTVI and real-time myocardial contrast echocardiography (RT-MCE) via intravenous infusion of self-made microbubbles, were performed, respectively. The systolic segmental wall thickening and subendocardial myocardial longitudinal velocities of risk segments before and after embolization were compared by using paired t analysis. The regional myocardial video intensity versus contrast time could be fitted to an exponential function: y=A.(1-exp(-beta.t)), in which the product of A and beta provides a measure of myocardial blood flow. RT-MCE showed that subendocardial normalized A.beta was decreased markedly from 0.99+/-0.19 to 0.35+/-0.11 (P<0.05) in 28 left ventricular (LV) myocardial segments after embolization, including 6 basal and 9 middle segments of lateral wall (LW), 8 middle segments of posterior wall (PW) and 5 middle segments of inferior wall (IW). However, there was no statistically significant difference in subepicardial layer before and after embolization. Accordingly, the ratio of A.beta of subendocardial myocardium to subepicardial myocardium in these segments was significantly decreased from 1.10+/-0.10 to 0.31+/-0.07 (P<0.05). Although the systolic wall thickening did not change 5 min after the embolization in these ischemic segments (29%+/-3% vs 31%+/-5%, P>0.05), the longitudinal peak systolic velocities (Vs) and early-diastolic peak velocities (Ve) recorded by QTVI were declined significantly (P<0.05). Moreover, the subendocardial velocity curves during isovolumic relaxation predominantly showed positive waves, whereas they mainly showed negative waves before the embolization. This study demonstrates that QTVI can more sensitively and accurately detect abnormal regional myocardial function and post-systolic systole caused by acute subendocardial ischemia.
Contrast Media ; Echocardiography/*methods ; Endocardium/physiopathology ; Microbubbles ; Myocardial Contraction/physiology ; Myocardial Ischemia/etiology ; Myocardial Ischemia/*physiopathology ; Myocardial Ischemia/*ultrasonography ; Myocardium/pathology ; Ventricular Function, Left/*physiology

OBJECTIVETo establish a reliable neonatal rat model of periventricular leukomalacia (PVL) which is expected to be similar to PVL of human preterm infants pathologically, and to explore the concomitant eye lesions in the PVL model.

METHODSTwo-old-day neonatal rats were randomly divided into a PVL group and a sham-operated group (n=19 each). The PVL model was established by the ligation of bilateral common carotid arteries, followed by a 30-min exposure to 8% oxygen. The cerebral infarction area was assessed with TTC staining 1 day after operation. Cerebral pathology was examined under a light micsrocope 2 and 21 days after operation. The examinations of eyes under a slip lamp and the pathology of eyeballs under a light microscope were performed 21 days after operation.

RESULTSThe TTC staining cerebral slices showed there were extensive white areas of infarction in the brain of the PVL group, with an infarction area of 53.45 +/- 33.90 mm3 and a percentage of infarction of (24.98 +/- 15.44)% . Significant cystic necrosis and apoptosis around the periventricular and subcortical white matter and mild damage in cortical neurons were observed in the PVL group 2 days after operation. The more obvious cystic necrosis around the periventricular area was found in the PVL group 21 days after operation. There were no pathological changes in the brain of the sham-operated group. All of rats in the PVL group had bilateral cataracts, however, no pathological changes were observed in their postbulbar tissues. The sham-operated group did not show eye abnormal.

CONCLUSIONSThe PVL animal model that was similar to PVL of human preterm infants pathologically was successfully established by the ligation of bilateral common carotid arteries, followed by 30-min hypoxia exposure, with a positive effect and a good repeatability. Cataract can also be induced by the method.

Animals ; Animals, Newborn ; Brain ; pathology ; Cataract ; etiology ; pathology ; Disease Models, Animal ; Female ; Humans ; Hypoxia-Ischemia, Brain ; complications ; Infant, Newborn ; Leukomalacia, Periventricular ; etiology ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

A 33-year-old male receiving dorsal penile nerve block (DPNB) for circumcision exhibited a postoperative ischemic change over the glans penis. The event occurred nearly 24 hours after the procedure. The patient was treated with intravenous pentoxifyllin and hyperbaric oxygenation. Total reverse of the ischemia was observed. The complications associated with circumcision and DPNB were reviewed and discussed.
Adult ; Circumcision, Male ; adverse effects ; Humans ; Infection ; etiology ; pathology ; Ischemia ; etiology ; pathology ; Male ; Nerve Block ; adverse effects ; Penis ; blood supply ; pathology ; Pentoxifylline ; pharmacology ; Vasodilator Agents ; pharmacology

OBJECTIVETo investigate the clinical and imaging characteristics of acute hypoxic-ischemic brain injury (HIBI) due to perinatal sentinel events in neonates.

METHODSForty-six neonates with acute HIBI who were admitted between January 2004 and May 2013, and who had a history of major cardiopulmonary resuscitation, were enrolled in the study. They were classified into full-term and preterm infants to analyze the clinical and imaging characteristics.

RESULTSAmong full-term infants, the incidence rates of white matter injury, cortical injury, basal ganglia /thalamic injury, and brain stem injury were 95%, 90%, 75%, and 65%, respectively; among preterm infants, the incidence rates of white matter injury, cortical injury, basal ganglia/thalamic injury, and brain stem injury were 73%, 23%, 19%, and 15%, respectively. Compared with full-term infants, preterm infants had a significantly lower incidence of gray matter injury in the cortex, basal ganglia/thalamus, and brain stem (P<0.05). About 46% of all subjects had multiple organ dysfunction. The 20 full-term infants with HIBI had typical clinical manifestations; 19 (95%) of them had moderate or severe neonatal encephalopathy, with mixed lesions on magnetic resonance imaging (MRI), and moderate or severe basal ganglia/thalamic injury was found in 68% of these patients. Multiple organ dysfunction, various abnormal neurological manifestations, and arterial blood pH less than 7.1 were closely related to moderate or severe brain injury.

CONCLUSIONSWhite matter injury is the most common type of HIBI. Gray matter injury can be found in preterm infants, but the incidence is lower than that in full-term infants. Moderate or severe neonatal encephalopathy is mainly manifested as basal ganglia/thalamic injury on MRI. Evaluation of multiple organ dysfunction and abnormal neurological manifestations and early blood gas analysis are very important for the diagnosis of neonatal HIBI.

Acute Disease ; Brain ; pathology ; Female ; Humans ; Hypoxia-Ischemia, Brain ; diagnosis ; etiology ; pathology ; Infant, Newborn ; Magnetic Resonance Imaging ; Male

OBJECTIVETo understand the clinical characteristics of hypoxic-ischemic encephalopathy (HIE) in full-term infants and to explore the value of magnetic resonance imaging (MRI) for the early prediction of HIE prognosis.

METHODSThe medical data, including histories, clinical manifestations, MRI findings and follow-up outcomes, of 348 full-term infants with HIE between January 2001 and December 2005 were retrospectively reviewed.

RESULTSHIE patients (348 cases) accounted for 8.25% of in-patients (4220 cases) over the five years. The etiology of HIE mainly attributed to birth asphyxia (76.2%), consisting of mild asphyxia (59.2%) and severe asphyxia (40.8%). A poor outcome was confirmed in 10.1% of these patients, including 27.3% in severe HIE, 10.0% in moderate HIE and 1.5% in mild HIE cases. All of patients whose MRI showed diffusion intraparenchymal hemorrhages and cerebral infarctions had poor outcomes. Fourteen (87.5%) out of the 16 cases with basal ganglia and thalamic or internal capsule injury and 9 (81.8%) out of the 11 cases with cytotoxic brain edema diagnosed by diffusion weighted imaging had poor outcomes.

CONCLUSIONSHIE is one of common diseases in newborn infants. The etiology of neonatal HIE mainly attributed to birth asphyxia, mild asphyxia accounting for a greater proportion. MRI findings can be helpful for the early prediction of HIE prognosis.

Brain ; pathology ; Humans ; Hypoxia-Ischemia, Brain ; diagnosis ; etiology ; pathology ; Infant, Newborn ; Magnetic Resonance Imaging ; methods ; Prognosis ; Retrospective Studies

Adult ; Arterio-Arterial Fistula ; complications ; Coronary Vessels ; pathology ; Embolization, Therapeutic ; Humans ; Male ; Myocardial Ischemia ; etiology ; therapy ; Pulmonary Artery ; pathology

The purpose of this study was to identify time-related changes in clinical, MRI, histopathologic, and immunohistochemical findings associated with ischemic stroke in dogs. Additionally, the association of cerebrospinal fluid (CSF) and tissue levels of interleukin (IL)-6 with clinical prognosis was assessed. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in nine healthy experimental dogs. The dogs were divided into three groups according to survival time and duration of the experimental period: group A (survived only 1 day), group B (1-week experimental period), and group C (2-week experimental period). Neurologic status was evaluated daily. Magnetic resonance imaging (MRI) was performed according to a predetermined schedule. Concentration of IL-6 in CSF was measured serially after ischemic stroke. Postmortem examination was performed for all experimental dogs. During histopathological examination, variable degrees of cavitation and necrosis due to neuronal cytopathic effects, such as pyknotic nuclei and cytoplasmic shrinkage, were observed on the affected side of the cerebral cortex in all dogs. Immunohistochemistry specific for IL-6 showed increased expression in the ischemic lesions. CSF IL-6 concentrations and ischemic lesion volumes 1 day after ischemic stroke were significantly higher in group A compared to groups B and C.
Animals ; Brain Ischemia/*etiology ; Dogs ; Female ; *Immunohistochemistry ; *Infarction, Middle Cerebral Artery ; *Magnetic Resonance Imaging ; Male ; Stroke/*pathology

Antiviral Agents ; therapeutic use ; Cytokines ; metabolism ; Dendritic Cells ; immunology ; metabolism ; pathology ; Endotoxemia ; complications ; pathology ; Hepatitis B ; complications ; pathology ; Humans ; Hypoxia ; complications ; pathology ; Ischemia ; complications ; pathology ; Liver ; metabolism ; pathology ; Liver Failure ; etiology ; immunology ; pathology ; therapy ; T-Lymphocytes ; immunology ; pathology