Endothelial Lined Skeletal Muscle Ventricles: Open and Percutaneous Seeding Techniques

Twelve bilateral skeletal muscle ventricles (SMVs) were constructed in six dogs by wrapping each latissimus dorsi muscle around a cylindrical, plastic mandrel (volume 30 cc). After 6 to 10 weeks, five dogs had one of their SMVs seeded with allogeneic cultured canine endothelial cells (8 times 10⁶ cells/pouch) via an open technique, while the contralateral SMV was seeded by percutaneous injection of cells into the space around the mandrel. After 1 week, the SMVs were excised. Viable, adherent endothelial cells were present in all seeded pouches; this was confirmed via fluorescent microscopy with several endothelial cell markers: KLH-2, dilacetylated low-density lipoprotein and antibodies to von Willebrand factor. The inner lining of the SMVs were also examined with scanning and transmission electron microscopy; the highest concentration of cells were seen at the apex where a continuous endothelial monolayer was observed. No significant difference in the distribution or the morphology of the endothelial lining was noted between the open and percutaneous seeding techniques. These data show that SMVs can be seeded with an endothelial monolayer using both open and percutaneous techniques.     

Blurred vision caused by inflammation of the optic nerves due to a pituitary abscess

A 48-year-old woman was admitted to our institution complaining of headache and a 2-month history of blurred vision and increased urinary volume. T(1)-weighted magnetic resonance (MR) imaging with gadolinium showed a ring-enhanced mass lesion in the pituitary. Fluid-attenuated inversion recovery MR imaging showed high-intensity lesions in the optic nerves, hypothalamus, and thalamus. The histological diagnosis was pituitary abscess. The blurred vision was caused by inflammation, but not compression, of the optic nerves due to the pituitary abscess outside the hypophysis.     

Postoperative hyperperfusion associated with steal phenomenon caused by a small arteriovenous malformation

A 41-year-old woman presented with a small occipital arteriovenous malformation (AVM) manifesting as headache. Cerebral angiography showed an AVM in the right occipital lobe fed by the right temporooccipital artery and draining into the superior sagittal sinus and right transverse sinus. Single photon emission computed tomography showed the steal phenomenon in the ipsilateral temporal cortex fed by the main feeding artery preoperatively, and hyperperfusion in the same cortex after removal of the AVM. Postoperative systolic blood pressure was maintained between 100 and 120 mmHg to avoid disastrous hemorrhagic complications. Cerebral blood flow evaluation before and after surgery is important to avoid postoperative disastrous complications even in patients with small AVM.     

Mesenchymal cells infiltrating a bladder acellular matrix gradually lose smooth muscle characteristics in intraperitoneally regenerated urothelial lining tissue in rats

OBJECTIVE: To characterize serial long-term histological changes in mesenchymal cells infiltrating a collagen-based matrix, as in a hollow organ with differentiated urothelial lining created intraperitoneally by grafting cultured urothelial cells, mesenchymal cells with smooth-muscle immunohistochemical characteristics infiltrated into the scaffold, despite no mesenchymal cells being seeded into the scaffold before grafting. MATERIALS AND METHODS: To regenerate a urothelial lining tissue intraperitoneally, rat urothelial cells were cultured and seeded with the feeder-layer technique onto bladder acellular matrix (BAM). After 7 days of cultivation to attach urothelial cells on the BAM, the matrix was folded with the urothelial cells inside and grafted onto the mesentery of the previously partially cystectomized rat. RESULTS: The grafted urothelial cells on the BAM, which formed a monolayer before grafting, stratified into three to four layers as early as 4 days after grafting. Although the regenerated urothelium became thinner with time, there was urothelial stratification and a peculiar angular appearance on the apical surface of the regenerated urothelium even after 56 days. The mesenchymal cells infiltrating the BAM showed positive immunohistochemical staining to alpha-smooth muscle actin or desmin at 7 days. Subsequently, the number of actin- or desmin-positive cells gradually decreased with time. On transmission electron microscopy, the infiltrating mesenchymal cells were characterized as myofibroblasts at 7 days. Smooth muscle-like cells were identified at 14 and 28 days, and fibrocytes were the main population at 56 days. CONCLUSIONS: Although epithelial-mesenchymal interactions have been assumed to be one of the most critical factors in smooth-muscle development, mesenchymal cells infiltrating the scaffold in this intraperitoneal regeneration model gradually lost smooth muscle characteristics with time. These results suggest that interactions between cultured urothelial cells and infiltrating mesenchymal cells alone could not maintain the smooth muscle character of infiltrating mesenchymal cells.     

Calcium antagonists and ischemic heart disease

Long-acting calcium antagonists, which have a wide-variety of anti-atherogenic properties, are well-tolerable and highly efficacious blood pressure lowering agents. Since a number of large prospective trials demonstrated the improvement of clinical outcomes in patients with coronary artery diseases, long-acting calcium antagonists may play a central role in the therapeutic strategy for ischemic heart disease.     

Intracerebral schwannoma clinically and radiologically mimicking meningioma

A case of intracerebral schwannoma (ICS) occurring in a 33-year-old woman is presented. The patient's history of headache, numbness, tingling and the recent development of weakness of the right upper extremity with right facial droop began during pregnancy. Magnetic resonance imaging (MRI) showed a 4 x 2 x 2 cm heterogeneous, gadolinium-enhanced mass at the left frontoparietal junction, with peritumoral edema and a dural-based attachment. During her pregnancy, the mass increased in size. The surgically resected specimen consisted of lobulated, somewhat gelatinous soft tissue. Microscopically, the tumor demonstrated classic biphasic Antoni type A and B patterns, admixed with degenerative changes. Immunohistochemically, the neoplastic cells were positive for S-100 protein (diffuse and strong), CD34 (primarily in Antoni B areas), glial fibrillary acidic protein (GFAP; weak and diffuse) and calretinin (mainly in Antoni A areas), while none was positive for CD31, estrogen and progesterone receptors, bcl-2, or epithelial membrane antigen (EMA). Ultrastructurally, basal laminae and Luse bodies were identified. The differential diagnosis includes fibrous meningioma, solitary fibrous tumor, and ICS. Twenty-seven cases of ICS were reviewed in which the histological diagnosis was confirmed immunohistochemically or ultrastructually, and the cases were summarized (including the present case). A combined use of immunostains (S-100 protein, EMA, CD34, and maybe calretinin) is of great help in distinguishing ICS from its histological mimickers.     

Transplantation of embryonic stem cell-derived neural stem cells for spinal cord injury in adult mice

AIMS: To investigate the efficacy of embryonic stem cell-derived neural stem cells (NSCs) for spinal cord injury (SCI) in mice and whether a combination treatment with thyroid hormone provides a more effective ES cell-based therapy. METHODS: Nestin-positive NSCs were induced from undifferentiated mouse ES cells by a step-by-step culture and used as grafts. Thirty-six mice were subjected to an SCI at Th10 and divided into three groups of 12. Graft cells were transplanted into the injury site 10 days after injury. Group 1 mice were left under observation without receiving graft cells, while mice in Group 2 received 2 x 104 graft cells, and those in Group 3 received 2 x 104 graft cells and were treated with a continuous intraperitoneal injection of thyroxin using osmotic mini-pumps. Behavioral improvement was assessed by a scoring system throughout the experimental period until post-transplantation day (PD) 28. RESULTS: Mice in Groups 2 and 3 demonstrated an improved behavioral function, as compared to those in Group 1 after PD 14. There was no significant difference in behavioral recovery between Groups 2 and 3. CONCLUSIONS: Transplantation of ES-NSCs into the injury site was effective for SCI, while thyroxine did not deliver additional effectiveness.     

Increased accumulations of AMsopropyl-p-[123I]-iodoamphetamine related to tumefactive multiple sclerosis

We present a 21-year-old woman with tumefactive multiple sclerosis (MS) that exhibited a rapidly progressive course. There were multiple tumor-mimicking contrast-enhance lesions with surrounding edema and mass effect on magnetic resonance imaging. Both early and delayed brain single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]-iodoamphetamine demonstrated increased accumulations of the tracer and a high retention on the lesions. The SPECT findings represent a diagnostic pitfall for distinguishing MS from malignant brain tumors in patients with intracranial tumor-like lesions.     

Comparative toxicity study of 2,4,6-trinitrophenol (picric acid) in newborn and young rats

The toxicity of oral 2,4,6-trinitrophenol (TNP) was determined in newborn rats, and compared with that in young rats. In newborn rats, males and females were given TNP at 0, 16.3, 81.4 or 407 mg/kg per day on postnatal days (PND) 4-17 for the dose-finding study, and at 0, 4.1, 16.3 or 65.1 mg/kg per day on PND 4-21 for the main study. Deaths, lower body weight (BW) and behavioral changes were found at 81.4 and 407 mg/kg per day in the dose-finding study, and lower BW was observed in males at 65.1 mg/kg per day during the dosing period of the main study. In young rats, 5-week-old males and females were given TNP at 0, 20, 100 or 500 mg/kg per day for 14 days as the dose-finding study and at 0, 4, 20 or 100 mg/kg per day for 28 days as the main study. Deaths were observed at 500 mg/kg per day in the dose-finding study. Deaths or changes in BW were not found at 100 mg/kg per day or less. At 100 mg/kg per day, hemolytic anemia and testicular toxicity were found. In conclusion, toxicity profiles induced by TNP were markedly different between newborn and young rats.