Cystic spinal cord tumors: Magnetic resonance imaging correlated to histopathological findings

We report the characteristics of magnetic resonance imaging (MRI) of cystic intradural extramedullary spinal cord tumors (cystic neurilemmoma, epidermoid cyst, and enterogeneous cyst). T1-weighted MRI enhanced with gadolinium-DTPA clearly demonstrated the rim morphology of these tumors. The comparison between the rim enhancement pattern and histopathological findings offered possible qualitative diagnosis of these cystic spinal cord tumors by MRI.     

The Mandibular Cartilage Metabolism is Altered by Damaged Subchondral Bone from Traumatic Impact Loading

Osteoarthritis (OA) in the temporomandibular joint (TMJ) is a degenerative disease caused by excessive external loading. Recently, it was reported that the damage in the mineralized subchondral bone caused by traumatic impact-loading is responsible for the initiation and progression of cartilage degeneration. Thus far, we have hypothesized that cytokines released from damaged subchondral bone from impact-loading affect the cartilage catabolism under pathological conditions. An impactor of 200 gw was dropped onto the top of a porcine mandibular condyle. After organ culture for 2 days, we investigated the association between the subchondral bone and cartilage using histological and biochemical experiments. The impact-loading induced the expression of IL-1β immunohistochemically and prominently up-regulated IL-1α and IL-1β mRNA levels in subchondral bone. We confirmed a significant decrease in type II collagen and aggrecan mRNA expressions in chondrocytes by co-culture with osteoblasts after impact-loading, and significant increase in mRNA and protein expressions of IL-1β in subchondral osteoblasts from impact-loaded subchondral bone. The mRNA expressions of type II collagen, aggrecan, and type X collagen in chondrocytes were decreased significantly by the co-culture with osteoblasts pre-treated by IL-1β, -6, and TNF-α. Among them, osteoblasts pre-treated by IL-1β affected chondrocytes most strongly. It was also shown that IL-1β-treated osteoblasts enhanced the MMP-1 mRNA level most markedly in chondrocytes among the four cytokines. These results suggest that the TMJ subjected to impact-loading can increase directly IL-1β synthesis in the subchondral region, subsequently altering the metabolism of adjacent cartilage and may eventually resulting in the onset and progression of TMJ-OA.     

The Complete Nucleotide Sequence of the PanAsia Strain of Foot-and-Mouth Disease Virus Isolated in Japan

The complete nucleotide sequence of the foot-and-mouth disease virus (FMDV) O/JPN/2000 strain, the PanAsia strain, was determined by cycle sequencing and primer walking. The 5 end of the genome upstream from homopolymeric poly(C) tract (S-fragment) was 367 nucleotides in length, and the remainder of the genome (L-fragment), excepting the poly(A) tail, was 7808 nucleotides. The L-fragment contains a single open reading frame of 6996 nucleotides terminating at a UAA codon 96 bases from the 3 poly(A) sequence. Comparison of sequences shows that the length of the structural and non-structural protein coding regions are identical to those in the O1/Kaufbeuren strain, and no striking differences such as deletion or insertion were observed between them.     

Anti-angiogenic and anti-tumor activities of isoflavonoids from the rhizomes of Belamcanda chinensis

The present study was carried out to clarify whether tectorigenin and tectoridin isolated from the rhizomes of Belamcanda chinensis (Iridaceae) inhibit angiogenesis by the experimental methods in vitro and in vivo. Tectorigenin and tectoridin decreased angiogenesis of both chick embryos in the chorioallantoic membrane assay and basic fibroblast growth factor-induced vessel formation in the mouse Matrigel plug assay. Both compounds also reduced the proliferation of calf pulmonary arterial endothelial (CPAE) cells and found to possess relatively weak gelatinase/collagenase inhibitory activity in vitro. Tectorigenin exhibited a much stronger anti-proliferative activity than its glycoside, tectoridin and was almost equipotent to that of genistein, a reference drug. Tectorigenin, when administered subcutaneously at the dose of 30 mg/kg for 20 days to mice implanted with murine Lewis lung carcinoma (LLC), caused a significant inhibition of tumor volume by 30.8 %. Tectorigenin and tectoridin, when treated i. p. at the same dosage for 10 days to ICR mice bearing sarcoma 180, caused a significant suppression in tumor weight by 44.2 and 24.8 %, respectively.     

Clinical evaluation of double stenting for duodenal and biliary obstructions caused by pancreatic head carcinoma using covered self‐expandable metallic stents

Five patients with non‐resectable pancreatic head carcinoma complicated by duodenal and biliary obstructions were successfully treated by double stenting with covered self‐expandable metallic stents (EMS). Diamond (Boston Scientific, Natick City, MA, USA) stents covered with a polyurethane membrane were used to treat biliary obstructions, whereas covered Ultraflex (Boston Scientific) stents for esophageal stenting were used to treat duodenal obstructions. That is, Diamond stents were initially placed in the biliary tract percutaneously in one patient and endoscopically in the remaining four patients. Subsequently, covered Ultraflex stents were placed in the duodenum. Double stenting with EMS was successfully performed in all five patients without inducing early technical complications. All patients were able to take a liquid diet orally at a mean 1.6 days after the double stenting procedure and were able to eat solid foods thereafter. Sludge‐induced biliary obstructions were detected in two patients 3 and 6 months after the placement of EMS. However, recurrent biliary obstruction was not noted in the remaining three patients. The EMS left in the duodenum were not obstructed during the observation period. The survival period of the patients ranged from 86 to 363 days (mean 172 days). There have not been any reports evaluating the usefulness of double stenting using covered EMS for duodenal and biliary obstructions. Because favorable results were obtained by double stenting in our patients, stenting for duodenal and biliary obstructions caused by non‐resectable pancreatic head carcinoma may become a useful treatment modality substituting for bypass surgery.     

Effect of systemic zinc administration on delayed neuronal death in the gerbil hippocampus

The divalent cation zinc has been reported to possess several physiological properties such as blocking apoptotic cell death through an inhibitory effect on Ca²⁺-Mg²⁺ endonuclease activity, or modulating the neurotoxicity via glutamate receptor subtypes. In the present study, we investigated the effect of peripherally injected zinc on delayed neuronal death seen in the hippocampus after transient global ischemia, in order to elucidate a possible beneficial role on zinc in ischemic neuronal cell death. Forty-five adult Mongolian gerbils of both sexes underwent transient bilateral clipping of the common carotid arteries for 3 min. In the pretreated animals, ZnCl₂ (20 mg/kg) was injected subcutaneously once, 1 h before ischemia (superacute group; n=6) or twice at 24 and 48 h before ischemia (subacute group; n=14). Histological survey was carried out 3 days later by in situ DNA fragmentation method and 4 days later by hematoxylin-eosin staining by semiquantatively counting dead neurons in the CA1 sector. Subacute zinc pre-administration significantly reduced the nuclear damage and subsequent neuronal death; however, superacutely pre-administered zinc did not protect hippocampal neurons against ischemia but it did not aggravate the effect of ischemia, either. The present study suggested that transfer of exogenous zinc into the intracellular space is required for neuroprotection, presumably via the anti-endonuclease activity.     

Abdominal vagotomy attenuates interleukin-1β-induced nitric oxide release in the paraventricular nucleus region in conscious rats

Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO₂⁻) and nitrate (NO₃⁻) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO₂⁻ and NO₃⁻ levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region.     

A novel AMPA receptor antagonist, YM872, reduces infarct size after middle cerebral artery occlusion in rats

The neuroprotective effect of YM872 ([2.3-dioxo-7-(1H-imidazol-1-yl) 6-nitro-1,2,3,4-tetrahydro-1-quinoxalinyl]acetic acid monohydrate), a novel α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor antagonist with improved water solubility, was examined in a rat focal cerebral ischemia model. Rats were subjected to permanent middle cerebral artery (MCA) occlusion using the intraluminal suture occlusion method for 24 h. YM872 was intravenously infused for 4 h (20 and 40 mg/kg/h) or 24 h (10 and 20 mg/kg/h), starting 5 min after the MCA occlusion, to investigate the effect of prolonged duration of the treatment on infarct volume. In the 4 h infusion study, YM872 reduced the cortical infarct volume by 48% at a dose of 40 mg/kg/h. YM872 did not significantly reduce the infarct at 20 mg/kg/h for 4 h. In the 24 h infusion study, however, YM872 markedly reduced the cortical infarct volume by 62%, even at 20 mg/kg/h. The present study indicates that the neuroprotective effect of YM872 is enhanced by extending the duration of treatment, and demonstrates the benefit of the prolonged treatment with AMPA antagonists following focal cerebral ischemia. YM872, a highly water soluble compound, is applicable to investigate the role of AMPA receptors in ischemic models without concern about nephrotoxicity and could be useful in the treatment of human stroke.     

The effects of external cues on ankle control during gait initiation in Parkinson's disease

The present study investigated the effects of external cues on motor control of the ankle joint during gait initiation in patients with Parkinson's disease (PD) and in age-matched healthy subjects. The soleus H-reflexes were recorded during self-generated and cue-triggered gait initiation. The tibialis anterior muscle burst during cue-triggered gait initiation was found to be significantly larger than that during self-generated gait initiation in both groups. External cues significantly increased soleus H-reflex depression during gait initiation in PD patients, although this significant increase was not present in healthy subjects. These findings indicate that external cues affect motor control of the extensor muscle of the ankle joint during gait initiation in PD patients.