A Reproducible and Simple Model of Permanent Cerebral Ischemia in CB-17 and SCID Mice.

In order to evaluate novel stroke therapies, it is essential to utilize a highly reproducible model of focal cerebral ischemia. Though a range of rodent stroke models has been employed in the literature, there are persistent issues regarding reproducibility of the ischemic zone, as there is considerable inter-animal and inter-laboratory variation. We have developed a highly reproducible model of stroke that involves direct electrocoagulation of the MCA in SCID (CB-17/lcr-scid/scidJcl) and CB-17 (CB-17/lcr-+/+Jcl) mice. Using a modification of the Tamura method, our results demonstrate reproducible cortical infarction with high survival in the chronic period (up to 180 days) in SCID and CB-17, but not in C57BL/6, mice. We believe that our preclinical model represents a step forward for testing future therapeutic methods potentially applicable to patients with stroke.

Quantitative evaluation of blood-cerebrospinal fluid barrier permeability in the rat with experimental meningitis using magnetic resonance imaging.

Disruption of the blood-brain barrier (BBB) and/or the blood-cerebrospinal fluid barrier (BCSFB) is thought to be one of the major pathophysiological consequences of meningitis and contributes to the development of adverse neurological outcomes. In order to clarify this hypothesis further, we sequentially quantified the permeability of these barriers with magnetic resonance imaging (MRI) contrast enhancement using gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) in rats with various experimentally-induced meningitis. Meningeal inflammation was elicited by an intracisternal injection of interleukin (IL)-1beta, prostaglandin (PG) E(2), or lipopolysaccharide (LPS). Barrier permeability was calculated from the gadolinium-enhancement ratio (GER) in the subarachnoid space (SAS). The secretion of Gd-DTPA into the SAS was monitored by T1-weighted imaging after an intravenous injection of Gd-DTPA. As a significant linear correlation was observed between the GER and the standard solution, the concentration of the secreted Gd-DTPA were determined from the GER. The maximal intensity in SAS was detected at 5min after Gd-DTPA administration and it declined gradually. Among the inflammatory agents, IL-1beta was found to induce the most severe meningitis as determined from the GER. The concentration of Gd-DTPA in the SAS increased in a dose-dependent manner following IL-1beta intracisternal injection. On the other hand, no significant changes in signal intensity of the brain parenchymal areas due to IL-1beta injection were observed. The findings suggest that the permeability of the BCSFB can be evaluated quantitatively by calculating the GER. MRI with Gd-DTPA provides a useful method to monitor the change in the permeability to the brain barriers.

Clinicocytopathology of breast cancers with a ring-like appearance on ultrasonography and/or magnetic resonance imaging.

On breast cancer imaging some cancers have an anechoic or high-echoic zone in the tumor on ultrasonography and ring-shaped enhancement on contrast-enhanced magnetic resonance imaging (MRI) with high intensity in the central area of the tumor on T2-weighted imaging, necessitating their differentiation from benign disease. Thus, nine breast cancers with a ring-like appearance on imaging were analyzed on cytopathology. Histologically the cancer cells of these lesions showing a ring-like appearance were located in the periphery of the tumor, with a central hypocellular zone. Five such lesions with a thick, doughnut-like appearance were identified as cancers with acellular zones (CAC), and four lesions with a thinner, rim-like appearance as matrix-producing carcinomas (MPC). The percentage ratio of the cancer-zone width to the tumor diameter was 26.4 +/- 7.8 and 8.0 +/- 3.2 (mean +/- SD), respectively (P= 0.003). Cytologically, highly atypical, naked-nucleus cells were observed in eight of the nine cancers. In two MPC and three CAC, cartilage matrix and amorphous material, respectively, were observed in the background. In summary, the present series of breast cancers having a ring appearance on imaging did not have uniform cytopathological features. They were classified as MPC or CAC, and cytology was useful in their diagnosis and differentiation in some cases.

Scalp acupuncture effects of stroke studied with magnetic resonance imaging: different actions in the two stroke model rats.

BACKGROUND: Scalp acupuncture (SA) therapy on strokes has been empirically established and widely used in clinics in China. The evidence from clinical studies suggests that SA produces significant benefits for some patients with stroke. METHODS: The effect of scalp acupuncture was studied using MRI for two different stroke models: spontaneously hypertensive stroke-prone (SHR-SP) rats and rats with transiently induced focal cerebral ischaemia by middle cerebral artery occlusion for 2 h (MCAO rats). RESULTS: Stroke onset in SHR-SP rats was characterised by a development of vasogenic oedema without any appearance of cytotoxic oedema. Scalp acupuncture reduced rapidly neurological dysfunction in SHR-SP rats and reduced the volume of the vasogenic oedema during the same period. In contrast, in MCAO rats, focal cerebral ischaemia caused an immediate development of cytotoxic oedema without any appearance of vasogenic oedema. Vasogenic oedema developed after reperfusion. Scalp acupuncture had no significant effects on the cytotoxic oedema, vasogenic oedema or neurological dysfunction of the MCAO rats within the time span examined. CONCLUSION: Scalp acupuncture had a rapid and strong effect on neurological dysfunction only in the hypertensive stroke-model by reducing the vasogenic oedema. Our results suggest that, if there are similar underlying mechanisms in human strokes, scalp acupuncture may be more beneficial for patients with strokes of hypertension-caused vasogenic origin than ischaemic origin.

Effect of cilostazol on delayed cerebral vasospasm after subarachnoid hemorrhage in rats: evaluation using black blood magnetic resonance imaging.

The purpose of this study was to use black blood magnetic resonance imaging (BB-MRI) to assess delayed cerebral vasospasm (DCV) after subarachnoid hemorrhage (SAH) in rats, and evaluate whether delayed treatment with the anti-platelet agent cilostazol was effective on DCV. BA vasospasm was sequentially assessed at 1, 2, and 3 h, and 1-6 days after SAH by BB-MRI. BB-MRI clearly visualized biphasic vasospasm; early vasospasm at 1 h later and the maximal DCV at day 2. Cilostazol was perorally administered twice at day 1 after having confirmed significant DCV using BB-MRI. The effect of cilostazol on DCV was evaluated at day 2. Cilostazol significantly attenuated DCV and suppressed the levels of malondialdehide and 8-isoprostane in CSF after SAH. This study shows that BB-MRI is a useful and less invasive method for the evaluation of DCV, and cilostazol may be effective on DCV.

Cilostazol attenuates gray and white matter damage in a rodent model of focal cerebral ischemia.

BACKGROUND AND PURPOSE: To evaluate whether delayed treatment with the antiplatelet agent cilostazol reduces the volume of infarction in the gray and white matter in a rodent model of permanent focal cerebral ischemia and to explore the mechanism of the neuroprotective effect in vivo. METHODS: Cilostazol (30 or 50 mg/kg) or vehicle was administered by gavage 30 minutes and 4 hours after the induction of cerebral ischemia by permanent occlusion of the left middle cerebral artery (MCA). Animals were euthanized 24 hours after MCA occlusion, and the volume of gray matter damage was evaluated by quantitative histopathology. Axonal damage was determined with amyloid precursor protein immunohistochemistry. Dynamic susceptibility contrast MRI was used to assess regional cerebral blood volume (CBV) and cerebral blood flow (CBF). RESULTS: Treatment with the higher dose of cilostazol (50 mg/kg) significantly reduced the volume of gray matter damage and axonal damage in the cerebral hemisphere by 45.0% (P<0.02) and 42.4% (P<0.002), respectively, compared with the control group. Relative CBV in the peri-infarct area after MCA occlusion was significantly increased in the cilostazol-treated group (50 mg/kg) compared with the control group (P<0.05). Relative CBF tended to be higher in the cilostazol-treated group compared with the control group. CONCLUSIONS: Treatment with cilostazol significantly reduced the gray and white matter damage associated with permanent focal ischemia. Cilostazol improved CBV and CBF in the peri-infarct area. The major action of cilostazol is to increase perfusion in the ischemic penumbra.

Fixation of silicone stents in the subglottic trachea: preventing stent migration using a fixation apparatus.

Silicone stents are widely used to treat benign or malignant airway stenosis. However, since straight silicone stents placed into the subglottic trachea to treat stenosis display a high risk of migration, novel approaches are required. The present report outlines our method of external fixation for silicone stents in the subglottic trachea. This technique utilizes a fixation apparatus, is readily performed, and may help to overcome the hesitation seen in placing silicone stents for subglottic tracheal stenosis.

Continuous muscle stretch prevents disuse muscle atrophy and deterioration of its oxidative capacity in rat tail-suspension models.

OBJECTIVE: The purpose of this study was to evaluate the effect of continuous muscle stretch on disuse-atrophied muscles. DESIGN: Sprague-Dawley rats were used and divided into five groups: control group, hind limb suspended for 3 and 7 days, and hind-limb suspension plus strenuous continuous muscle stretch for 3 and 7 days. In the hind-limb suspension plus strenuous continuous muscle stretch groups, the gastrocnemius-plantaris-soleus muscles were stretched using a plastic plate that immobilized the ankle joint at the maximum dorsal flexed position during the hind-limb suspension period. The intracellular energy metabolism of the working muscle during electric stimulation was evaluated by phosphorus-31 magnetic resonance spectroscopy in vivo. Changes in phosphocreatine, inorganic phosphate, and the intracellular pH were monitored to evaluate intramuscular oxidative capacity. Maximum tension and muscle wet mass were also measured. RESULTS: The oxidative capacity, muscle wet weight, and maximum tension decreased after hind-limb suspension. The muscle oxidative capacity at control levels was maintained during the first 3 days in muscles subjected to continuous strenuous stretch. It was also effective to prevent the decrease in muscle mass and maximum twitch tension during the initial 3 days. However, the effects did not persist. CONCLUSION: Continuous strenuous stretch was effective to prevent disuse muscle atrophy and its functional deterioration; however, its effects did not last long.

Amyloid tumor in the anterior mediastinum: report of a case.

A 33-year-old woman being treated for rheumatoid arthritis was referred to our hospital for investigation of a mediastinal mass. A chest computed tomography scan showed an anterior mediastinal mass, 8.5 x 7.0 cm in size, with a cystic lesion and calcification. These findings were suggestive of either a noninvasive thymoma or a mature teratoma. Therefore, we performed tumor resection and thymectomy. Histologically, the tumor consisted of diffuse deposits of massive eosinophilic amorphous material. The tumor was stained red-orange by Congo red, and the staining disappeared following potassium permanganate digestion. Based on these findings, a diagnosis of reactive amyloidosis of the amyloid A-protein-derived type was made. Amyloidosis in the mediastinum has rarely been described.

Incidental partial anomalous pulmonary venous connection in left lung cancer.

We present the case of a 79-year-old woman with partial anomalous pulmonary venous connection (PAPVC), discovered incidentally during upper left division segmentectomy for primary lung cancer. The left superior pulmonary vein originated from the hilum of the upper left lobe and flowed into the left brachiocephalic vein. The left inferior pulmonary vein was connected normally, and neither atrial septal defect nor other anomalous condition was present. Upper left lobectomy with ligation of the anomalous connected vein was performed, as the lingual segment was anatomically difficult to retain. Although this type of PAPVC is extremely rare, it is advisable to exercise caution when performing lung resection with the potential for PAPVC in mind.

Gene therapy eradicating distant disseminated micro-metastases by optimal cytokine expression in the primary lesion only: novel concepts for successful cytokine gene therapy.

The most serious problem in current gene therapy is that clinical applications have often led to unsatisfactory results. Here we show novel concepts and crucial factors that have been missing for successful cytokine gene therapy. A clinically-relevant mouse model of primary and micro-metastatic osteosarcoma was generated by subcutaneously and intravenously injecting murine osteosarcoma LM8 cells, in which adenoviral gene transduction efficiencies were extremely low; current therapies remain less effective for such disseminated micro-metastases. A single injection of adenoviral vector encoding interleukin-2 gene (Ad.IL-2) was given only into the established primary tumor. Notably, antitumoral immunity was successfully elicited by IL-2 secretion from connective tissues adjacent to the primary tumor, and this immunity not only suppressed primary tumor growth but also eradicated disseminated micro-metastases in distant organs. Most importantly, not only minimal side effects but also maximal therapeutic effects were exerted only in the case of injecting the optimal (i.e., not the highest) dose of Ad.IL-2, because spleen injuries caused by excessive levels of circulating IL-2 might diminish the therapeutic effect. Although the narrow range of the optimal therapeutic expression level of IL-2 may be crucial, it was feasibly determined by serum IL-2 levels. Thus, a crucial factor for successful cytokine gene therapy is not the high gene transduction efficiency in the tumor, which has been generally recommended, but the use of the optimal therapeutic expression level. In conclusion, just a single injection of Ad.IL-2 into a primary tumor lesion, which is feasible, not invasive and cost effective, is potently therapeutic for distant disseminated micro-metastases, as long as the optimal therapeutic level is monitored. These novel concepts, which contradict those of previous studies, warn researches about the possible problems with the ongoing clinical cytokine gene therapy.

Muscular oxidative capacity in ovariectomized rats discussion on the endurance performance of female athletes with sports-related-amenorrhea.

The purpose of this study was to evaluate the effects of ovariectomy on intramuscular energy metabolism in adult rats. Based on the results, we discussed the skeletal muscle metabolism in female athlete with sports related amenorrhea. Twenty-five adult (20-week-old) Sprague-Dawley female rats were used. Fifteen rats underwent ovariectomy (OVX group), and the other ten rats were sham-operated (Sham group). One and four weeks after surgery, muscular oxidative capacity was measured using (31)P-MR spectra of the gastrocnemius-plantaris-soleus (GPS) muscles group at rest and during electric stimulation. Wet weight and maximum tension of the whole GPS muscles group were also measured. From the MRS measurements, the muscle oxidative capacity in the OVX group was significantly lower than that in the Sham group (p < 0.05) at both one and four weeks after surgery. The muscle's wet weight one week after surgery in the OVX group was the same as the Sham group, while four weeks after surgery it was significantly greater than that in the Sham group (p < 0.05). There were no significant differences in maximum tension among the groups. In conclusion, in adult rats the oxidative capacity decreased due to ovariectomy despite the increase in muscle weight. It is suggested that the muscular endurance capacity in female adult athletes with sports related amenorrhea may deteriorate. Key PointsIn vivo measurement of muscular energy metabolism.Effects of ovariectomy on muscle function and volume.Muscle function of sports-related amenorrhea.

Cilostazol reduces brain lesion induced by focal cerebral ischemia in rats--an MRI study.

To investigate the effects of cilostazol on the hemispheric ischemic lesion, we monitored the apparent diffusion coefficient (ADC) and T2 images by MRI techniques in comparison with histology at the terminal of and after 24-h reperfusion following 2-h occlusion of middle cerebral artery (MCA). The ADC values of tissue water and T2-weighted images were quantified by high field magnetic resonance. No significant difference was observed by ADC image among vehicle and cilostazol treatment groups when measured during MCA occlusion. Oral treatment with cilostazol 30 mg/kg two times at 5 min and 4 h significantly suppressed the hemispheric lesion area and volumes when detected by ADC, T2 images and histology, but 3 and 10 mg/kg cilostazol were without effect. Cilostazol (30 mg/kg) significantly reduced the increased cerebral water content at the ischemic hemisphere compared with vehicle group. In line with these results, the neurological deteriorations were much improved in the cilostazol-treated group. Taken together, it is concluded that post-treatment with cilostazol exerts a potent protective effect against cerebral infarct size by reducing the cytotoxic edema.

Electrical stimulation prevents deterioration of the oxidative capacity of disuse-atrophied muscles in rats.

INTRODUCTION: The purpose of this study was to evaluate the effects of electrical stimulation on disuse-atrophied muscles. METHODS: Sprague-Dawley rats were used and divided into three groups: control (C), hind-limb suspended for 7 d (HS), and HS plus transcutaneous electrical stimulation for 7 d (ES). In the ES group, transcutaneous electrical stimulation was induced at 1 Hz for 1 h every day to condition the gastrocnemius-plantaris-soleus muscles. Muscle oxidative capacity was evaluated by 31P-MRS in vivo. Maximum tension and muscle wet mass were also measured. RESULTS: Muscle oxidative capacity decreased within 1 wk in HS; however, it was maintained when electric stimulation was applied to the suspended limb. The maximum twitch tension in HS was significantly smaller than that in C (p < 0.05), while in ES it did not differ from that in C. The muscle mass was significantly smaller in the HS and ES groups compared to C (p < 0.05). CONCLUSION: These data indicated that twitch electrical stimulation was effective in preventing deterioration of muscle functions, such as maximum tension and oxidative capacity, induced by 1 wk of disuse.

An optimal therapeutic expression level is crucial for suicide gene therapy for hepatic metastatic cancer in mice.

The most serious problem in current gene therapy is discrepancies between experimental data and actual clinical outcomes, which may be due to insufficient analyses and/or inappropriate animal models. We have explored suicide gene therapy by using various clinically relevant animal models and doubt the clinical use of maximal suicide gene expression, which has been generally recommended. To explore this subject further, we studied what expression level of suicide gene and what promoter led to the maximal clinical benefit in the case of hepatic metastatic cancer in mice. Therapeutic and adverse side effects of 4 adenoviral vectors that express herpes simplex virus thymidine kinase (HSV-tk) under different promoters were scrupulously investigated in 2 mouse models of hepatic metastasis of gastric cancer that possess clinical characteristics. Surprisingly, increases in HSV-tk expression beyond a certain point, achieved by the Rous sarcoma virus long terminal repeat promoter, not only enhanced the adverse side effects of lethal hepatotoxicity and ganciclovir-independent cytotoxicity but also failed to further increase therapeutic potential. Moreover, the carcinoembryonic antigen (CEA) tumor-specific promoter, the therapeutic potential of which had been underestimated, was much more useful-even in the case of low CEA-producing cancer-than had been previously reported. In conclusion, the optimal therapeutic expression level of a suicide gene is a novel concept and a crucial factor for successful cancer gene therapy. The present results, which contradict those of previous studies, alert researchers about possible problems with ongoing and future clinical trials that lack this concept.

Resection of synchronous lung and Vater's papilla cancer.

We present a case of a 78-year-old man with a synchronous double cancer of the lung and Vater's papilla. A pancreaticoduodenectomy was performed for Vater's papilla cancer and a partial lung resection for lung cancer. The pathological diagnosis of the tumors was a well differentiated tubular adenocarcinoma and well differentiated bronchioloalveolar carcinoma, respectively. Although most cases of synchronous double cancers involve lung and gastric cancers, a combination of lung and Vater's papilla is extremely rare. This patient is still alive with no recurrence for 5 years after the last operation.

Rapid-growth lung cancer associated with a pulmonary giant bulla: a case report.

A giant bulla of the lung is suggested as a risk factor for lung cancer. Here we report a case with lung cancer in a giant bulla, which showed rapid progression. A 57-year-old man, who had a history of heavy smoking, was admitted to our hospital due to hemoptysis. A chest X-ray revealed a giant bulla with a ground glass shadow and a high fluid level in the right upper lung. Sputum cytology was negative for malignant cells. A chest X-ray a month later showed increases of the size of the radio-opaque shadow and of the air-fluid retention, suggesting pulmonary hemorrhage from the giant bulla. Limited resection or lobectomy was indicated, but pneumonectomy was performed due to the severe air-leak. Macroscopically, a multiple nodular tumor arose from the bulla wall, which might be related to blood flow and necrotic tissue. The postoperative pathological diagnosis was papillary adenocarcinoma. Unfortunately, the patient developed a recurrence of carcinoma in the pleuroperitoneal cavity and died at 2.5 months after the operation. Based on this report and review of other cases in the literature, we should keep in mind the rapid progression of lung cancer in association with an emphysematous bulla.

The UPAO test in preoperative evaluation for major pulmonary resection: an operative case with markedly improved ventilatory function after radical pulmonary resection for lung cancer associated with pulmonary emphysema.

A 65-year-old man was admitted to our hospital for treatment of a squamous cell carcinoma in his right lung. Respiratory function testing showed an extremely reduced forced expiratory volume in 1 second (FEV1) of 1.0 l (29.9% of predicted), and a reduced FEV1/FVC ratio of 24.1%. Arterial blood gases on room air showed a pH of 7.41, a PaCO(2) of 36.7 mmHg, and a PaO(2) of 79.3 mmHg. To assess the predictive postoperative cardiopulmonary function, unilateral pulmonary artery occlusion (UPAO) testing was performed. In the condition of right main PA occlusion, the mean pulmonary artery pressure (mPAP), cardiac index (CI) and total pulmonary vessel resistance index (TPVRI) was 18 mmHg, 3.2 l/min/m(2) and 443.37 dyne.sec.cm(-5)/m(2), respectively. He underwent a middle lobectomy with combined partial resection of both the upper and lower lobes. He also underwent simultaneous resection of a giant bulla arising from the right upper lobe as lung volume reduction surgery. At 80 days after the operation, his FEV1 rose to 1.88 l, and the PaO(2) on room air was improved to 88.9 mmHg. UPAO testing was suggested to be more useful than routine pulmonary function test to determine the accurate predictive postoperative cardiopulmonary function and to decide indication for a radical operation.

Minute lung carcinoma associated with focal honeycombed lesion.

We report a case of minute lung carcinoma that developed in a focal honeycombed lesion in the right lung. A 70-year-old man presented hemosputum, and a cytological examination result was at class IV. A right lower lobectomy of the lung was performed. Microscopically, the thickened alveolar wall revealed tumor cells indicating a minute carcinoma, and showed squamous hyperplasia, metaplasia, and dysplasia, with the carcinoma in the distal airway epithelium. This peripheral lung carcinoma in a focal honeycombed lesion demonstrated the various stages of multistep carcinogenesis, which is recognized in hilar type squamous cell carcinoma. To date, the association between a honeycombed lesion and lung cancer has been poorly described. Here we have presented clear evidence of the association of this carcinoma with the honeycombed lesion.

Vasoactive peptides in a pulmonary embolism model.

PURPOSE: To investigate changes in atrial natriuretic peptide (ANP) and angiotensin II (AT-II) levels in a canine model of pulmonary embolism (PE), created by embolizing the left posterior pulmonary artery with gelatin powder. METHODS: Pulmonary arterial pressure (PAP) was measured before, immediately after, and 1 day after pulmonary artery embolization. Plasma ANP and AT-II levels were measured by radioimmunoassay (RIA) before and 1, 3, 7, 14, 21, and 28 days after embolization. ANP and AT-II levels were also measured by RIA in both embolized and nonembolized lung tissue 28 days after embolization. RESULTS: No changes in plasma ANP or AT-II were seen within 28 days after embolization. Although the ANP level in the nonembolized lung tissue was significantly increased, the level in the embolized lung tissue was significantly decreased compared with that of sham-operated control lung tissue. The AT-II level in the nonembolized lung tissue was significantly decreased compared with that of the control lung tissue, but the level in the embolized lung tissue did not change. CONCLUSION: Both ANP and AT-II in the nonembolized lung tissue reacted to compensate for vasoconstriction caused by the PE in this model.