Wnt signaling plays an essential role in neuronal specification of the dorsal spinal cord

In the developing spinal cord, signals from the roof plate are required for the development of three classes of dorsal interneuron: D1, D2, and D3, listed from dorsal to ventral. Here, we demonstrate that absence of Wnt1 and Wnt3a, normally expressed in the roof plate, leads to diminished development of D1 and D2 neurons and a compensatory increase in D3 neuron populations. This occurs without significantly altered expression of BMP and related genes in the roof plate. Moreover, Wnt3a protein induces expression of D1 and D2 markers in the isolated medial region of the chick neural plate, and Noggin does not interfere with this induction. Thus, Wnt signaling plays a critical role in the specification of cell types for dorsal interneurons.     

Bilateral tectal projection of single nigrostriatal dopamine cells in the rat

Employing fluorescent retrograde double/triple labeling techniques, we found that a substantial population of substantia nigra pars reticulata cells send divergent axon collaterals to both the ipsilateral striatum and bilateral superior colliculi in the rat. These multi-collateralized neurons were localized predominantly in the ventrolateral portion of the substantia nigra pars reticulata at its rostral level. Furthermore, tyrosine hydroxylase immunofluorescence histochemistry combined with fluorescent retrograde tracing techniques showed that the vast majority (more than 85%) of such specifically branched cells are dopaminergic. This novel nigral cell population seems to be in a strategic position to evoke dopamine-mediated motor impairments (i.e. abnormal saccadic eye movements in Parkinsonism) and/or behavioral syndromes (i.e. compulsive turning behavior) through the GABA-containing nigrotectal pathway.     

Effect of prostaglandin E1 on preservation injury of canine liver grafts preserved in UW solution

This study investigated whether prostaglandin E₁ (PGE₁) could reduce hepatic injury to the liver graft caused by harvesting and 24-h preservation in University of Wisconsin (UW) solution in a canine model. The PGE₁-treated group was intravenously administered 0.5 g/kg per minute of PGE₁ for 30 min before harvesting, as well as a concentration of 1 mg/l PGE₁ in the washout and UW solutions. In both the PGE₁-treated and the control group, all recipients survived for 1 week or more after transplantation. Arterial ketone body ratio (AKBR) remained over 1.0 in the early postoperative period. The PGE₁ group showed significant reductions in guanase, GOT, and LDH during the early postoperative period compared to the untreated control group. Histological examination disclosed partial mitochondrial swelling, hepatocyte vacuolation, and necrosis in the control group, while such abnormalities were rarely seen in the PGE₁ group. These results suggest that PGE₁ can effectively reduce hepatic injury to liver grafts preserved in UW solution prior to transplantation.     

Expression and localization of matrix metalloproteinases and tissue inhibitors of metalloproteinases as a prognostic factor in advanced colorectal carcinomas

To clarify the usefulness of matrix metallo-proteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as prognostic factors in advanced colorectal carcinoma, the immunohistochemical expressions of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1 and TIMP-2 were examined. Specimens were selected from 67 consecutive patients undergoing surgery for advanced colorectal carcinoma. The patterns of expression were compared with the prognoses of the patients. The patients with TIMP-2 expression in stroma adjacent to the tumor mass had better prognoses than those of the patients who had no TIMP-2 expression in normal stroma adjacent to the tumor (p<0.05), which probably acted as a block of cancer cell invasion. However, the expression of MMP-2, presumably acting as an antagonist to TIMP-2 was not related to the prognosis, and the MMP-1, MMP-2, MMP-3, MMP-9 and TIMP-1 expressions were not related to any clinicopathological factors examined.     

p53 status and prognosis in stage I-IIIa non-small cell lung cancer

To investigate the role of p53 abnormalities in predicting the survival of patients with non-small cell lung cancer (NSCLC), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and immunohistochemical analyses were performed on 74 and 67 tumor samples, respectively, from patients with pathological stage I-IIIa NSCLC. An abnormally migrating SSCP band was observed in 21 of 74 (28%) tumor specimens. DNA sequence analysis revealed 23 intragenic mutations including 3 small deletions and 20 point mutations. Immunohistochemical analysis using the DO-7 monoclonal antibody showed abnormal expression of p53 in 27 of 67 (40%) patients. The concordance rate between immunohistochemical and PCRSSCP analyses was 73% (49/67) in this study. Univariate and multivariate analyses demonstrated that abnormal expression of p53 may be associated with prolonged survival (p=0.0997 and 0.0099, respectively). In contrast, no relationship was observed between p53 mutation and overall survival (0.6968). These results suggest that p53 status and the survival outcome changes between immunohistochemical and mutational analyses in stage I-IIIa NSCLC.     

The effects of oligomers content and surface morphology on foreign-body tumorigenesis with polyetherurethanes: two years subcutaneous implantation study in rats

Three polyurethane materials were prepared by removing and adding the leachable oligomers from and to the same polyetherurethane (PEU). The three PEU materials were dissolved in tetrahydrofuran (THF) and dimethyformamide (DMF) and the solutions were cast on a glass plate to make films of smooth and foamed surfaces, respectively. These six materials and polydimethylsioxane (silicone) were implanted into subcutaneous pocket of rats for 2 years to evaluate the long-term effects around the implant. Among the smooth surface implants, PEU materials induced a higher incidence of tissue responses, including tumor formation than silicone. However, no relationship between the oligomer content and the tissue responses was found. Changing surface morphology from a smooth to a foamed one prolonged the latent period of tumor development and decreased the total tumor incidence.     

Non-invasive continuous hemodynamic measurement during operation for a child with coarctation of aorta

For non-invasive hemodynamic monitoring, DYNEMO 3000 (SOMETEC Inc) has a 10 mHz ultrasonic echo scan and a 5 mHz Doppler velocimeter connected to an echo-oesophageal probe allowing continuous measurement of the aortic diameter and of the blood flow velocity in the descending aorta. This device thus can only measure the aortic blood flow, but also calculate the stroke volume and the systemic vascular resistance. Moreover, the systolic time intervals and the length of the pre-ejection period can be measured with the oscillometric tensiometer and the electrocardiography. This paper describes a case in which this device was used for a child with coarctation of the aorta. The hemodynamic changes were measured continuously during coarctectomy. During the temporary bypass, the aortic blood flow and the stroke volume decreased, but on the other hand, the total vascular resistance increased at the same time. After the bypass, these parameters returned to the values before the bypass. We think that this device is useful as a non-invasive monitor to observe the hemodynamic changes continuously during operation for a child with congenital heart disease.