Experimental study and clinical use of poly(vinyl acetate) emulsion as liquid embolisation material

A new material, an emulsion of poly(vinyl acetate) was experimentally developed and clinically used to overcome several disadvantages in currently used liquid embolisation materials. The emulsion microparticles, 0.3–0.7 m in size, possessed cationic charge on the surface and hence aggregated immediately on contact with fluids containing anions. This inert polymer has the advantage that it does not induce a deleterious reaction in living tissue. Moreover, its medium is water and it is not adhesive, like the cyanoacrylates. Several concentrations of emulsion were injected into the renal arteries of dogs. For the investigation of tissue reactions and the possibility of recanalisation, the emulsion was injected into rats both subcutaneously and into the renal arteries. The renal artery injections in dogs showed adequate radiopacity and consistent complete occlusion. The lower the concentration of the emulsion, the smaller the arteries which could be occluded. Even at very low concentrations, however, venous occlusion did not occur. Histological study of the embolised rat kidney revealed no detectable damage in the vessel wall and no recanalisation for up to 6 months. The subcutaneously injected PVAc emulsion elicited mononuclear cell infiltration and gradual centripetal fibrosis, without any deleterious effect on the surrounding tissue. A cerebral arteriovenous malformation (AVM) was embolised using the material. Histology of the resected nidus showed findings similar to those in the animal experiments.     

Recurrent breast cancer at 21 years after resection detected by serum tumor markers and manifested as dermatomyositis

A 52-year-old Japanese woman developed dermatomyositis. She had undergone a standard radical mastectomy for left breast cancer 21 years earlier. Though no physical sign of recurrent breast cancer appeared clinically, levels of tumor markers were abnormally elevated. Therefore, tamoxifen and CAF therapy were given. Further, the clinical course of dermatomyositis almost paralleled the level of serum tumor markers and the clinical course of her recurrent breast cancer. These markers were useful for detecting the recurrence, following the metastatic disease, and monitoring her response to therapy.     

Bilateral synchronous renal cell carcinoma: report of three cases

We report here three cases of bilateral synchronous renal cell carcinoma. One of the 3 patients underwent bilateral partial nephrectomy, while the other 2 underwent combined partial nephrectomy and radical nephrectomy. All patients received adjuvant therapy of interferon-alpha and tegafur uracil. In the management of synchronous bilateral renal cell carcinoma, we discussed the selection of surgical procedure for primary lesions, i.e., based on the renal function of both sides, and the necessity of adjuvant therapy in such cases.     

Rathke cleft cyst: MR and biomedical analysis of cyst content

PURPOSE: At least one type of Rathke cleft cyst has unique MR findings, specifically, high intensity on T1-weighted images and iso- to low intensity on T2-weighted images relative to white matter. To clarify the influence of cyst content on MR images, we analyzed the cyst content by biomedical methods after surgical removal. METHOD: We studied five patients diagnosed with Rathke cleft cyst, whose MR images showed high intensity on T1-weighted images and iso- to low intensity on T2-weighted images. After surgery, total protein and cholesterol levels were quantified, and correlations of protein and cholesterol content with T1 and T2 signal intensities were performed in vitro. RESULTS: All five cysts had very high concentrations of protein (11,700-26,600 mg/dl, mean 17,940 mg/dl) with nearly no cholesterol (at most 2.0 mg/dl). Along with increases in protein concentration in vitro, the signal intensity of T1-weighted images increased, while that of T2-weighted images decreased. In contrast, the cholesterol concentration sequence influenced the signal intensity of neither T1- nor T2-weighted images. CONCLUSION: The unique MR finding of Rathke cleft cysts--high signal intensity on T1-weighted images and low signal intensity on T2-weighted images--might depend mainly on protein concentration, not on cholesterol.     

Coronary artery bypass grafting in two patients with single coronary artery

We experienced two patients with single coronary artery who underwent CABG using arterial grafts successfully. In two patients coronary angiography demonstrated a single coronary artery which was originated in left coronary sinus and was bifurcated to LAD and LCx, and then RCA branched off proximal LAD, passing in front of the right ventricular out flow tract (Sharbaugh Type L-IIa). To the first patient, a 52-year-old man who had angina on exertion due to long stenosis of RCA, CABG to RCA using RITA was carried out. To the second patient, a 57-year-old man who had inferior myocardial infarction due to 90% stenosis of proximal LAD, CABG to RCA using RITA and LAD using LITA was carried out. Single coronary artery without additional congenital cardiac anomalies may lead to myocardial ischemia, necessitating CABG as coronary reconstructions.     

A case of traumatic aneurysm of innominate artery with occlusion of right subclavian artery

A 42-year-old woman with history of chest blunt trauma from an automobile accident 250 days earlier had suffered easy fatigability of the right upper extremity. She had difference of blood pressure between upper extremities, 94/60 mmHg in the right and 126/70 mmHg in the left. Chest CT showed dilation of the innominate artery which compressed the trachea. Aortography showed an aneurysm of the innominate artery and occlusion of the right subclavian artery at its origin. The aneurysm of the innominate artery was resected and replaced with a 6 mm Dacron graft with aid of the external shunt. The right subclavian artery was also reconstructed with same graft. The aneurysm of the innominate artery should be suspected as a rare complication in blunt trauma of the chest.     

Temporal and spatial profile of apoptotic cell death in transient intracerebral mass lesion of the rat

Apoptosis is involved in the pathogenesis of cerebral ischemia. Previous studies have confirmed that the brain surrounding an intracerebral hematoma develops ischemia. We investigated the number and distribution of cells exhibiting DNA fragmentation with apoptotic morphology in the transient intracerebral mass lesion to determine whether apoptosis contributed to the lesion progress after intracerebral hemorrhage (ICH). Transient intracerebral mass was created by inflation of a microballoon for 10 min (group A) or 2 h (group B) in the caudoputamen in rats, and brains were examined 1, 3, 6, 24, and 48 h after microballoon deflation. The lesion volume was calculated using parallel coronal sections with cresyl violet staining. Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine (dUTP)-biotin nick end labeling (TUNEL) was used to detect cells undergoing DNA fragmentation. Immunohistochemistry for Fas antigen was also done to ascertain molecular mechanisms of apoptosis. Histological examination of hematoxylin and eosin-stained sections showed the typical appearance of neuronal necrosis in the caudoputaminal lesion. Lesion volume in the caudoputamen gradually increased as time advanced from 1 to 48 h. Cells stained heavily by TUNEL with apoptotic morphology were detected in the lesion, but not in the inner boundary zone of the lesion. The number of these cells significantly increased from 6 to 24 h in each experimental group (p < 0.05). The cells with positive immunoreactivity for Fas antigen was prominently observed in the lesion at 6 h. The distribution of apoptotic cells and the rapid increase in the number of apoptotic cells after 24 h propose that apoptotic cell death may contribute to lesion core formation but not to gradual development of the lesion.     

Tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) stimulate osteoclastic bone resorption

As both tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 have been reported to inhibit bone resorption, we examined whether TIMP-1 or TIMP-2 in fetal calf serum (FCS), with which culture media were supplemented, affected osteoclastic bone resorption in vitro. Contrary to our expectation, almost complete suppression of osteoclastic bone resorption was observed when both TIMP-1 and TIMP-2 were removed from the FCS. Bone resorption was, however, almost fully restored by the addition of recombinant TIMPs. TIMPs stimulate bone resorption at significantly lower concentrations (∼ng/ml) than those (∼μg/ml) required to inhibit bone resorption. To understand the mechanism of TIMP-dependent bone resorption, we counted and compared the number of tartrate-resistant acid phosphatase-(TRAP-) positive and multinuclear cells in cultures containing either 10% FCS or TIMP-1-free and/or TIMP-2-free FCS. There was essentially no difference in number among these, suggesting that the TIMP role seems to be related to the functional expression of osteoclasts. Metallo-proteinase inhibitors, either BE16627B[l-N-(N-hydroxy-2-isobutylsuccinynamoyl)-seryl-l-valine] or R94138 {N-methyl-(3S)-2-[(2R)-2-hydroxycarbamoylmethylundecanoyl] hexahydropyridazine-3-carboxamide}, could not replace TIMPs, suggesting that the osteoclast-stimulating activity of TIMPs cannot be ascribed to merely their inhibitory effect on matrix metalloproteinases. Received: Oct. 15, 1998 / Accepted: April 5, 1999     

Finger bougie method compared with pyloroplasty in the gastric replacement of the esophagus

To elucidate the necessity of pyloroplasty for the gastric tube through the posterior mediastinum in esophageal surgery, gastric emptying and duodenogastric reflux (DGR) were evaluated in 16 cases undergoing an anterior pylorectomy (group P) and in 16 cases treated by the finger bougie method (group F). First, the obstruction and reflux symptoms were examined based on a patient questionnaire using a brief scoring system. The median value of the symptom score showed the patients in P to have more symptoms than those in F; however, the difference was not significant (8.0 vs 6.0). Secondly, the swallowed Tc O₄ ⁻ (85 MBq) was counted using a gamma camera at three sites on the sternal bone in the upright position based on a gastric transit scintigram. Both the descending time of the RI peak and the clearance rates were similar between the two groups. Thirdly, intragastric 24-h pH monitoring was carried out. Antimony pH sensors were anchored 5 and 15 cm below the esophagogastrostomy. We could not find any difference between the two groups in both the % time pH>4 and %time pH>7. These findings thus revealed no big difference between groups P and F. The finger bougie method to drain the vagotomized posterior mediastinal stomach was found to achieve results similar to conventional pyloroplasty, while it was also simpler and safer.