Studies on avian spinal cord chimeras. I. Neurological and histological manifestations.

Spinal cord chimeras were produced by replacing a small fragment of neural tube of a 2-day-old White Leghorn chicken embryo with a similar fragment from a Japanese quail embryo. The embryo mortality was 61%, and 72% of hatched birds were 'cripples' and had to be sacrificed within 5 days after hatching. Forty-nine chimeras, 10.9% of the total number of operated embryos, were alive for more than 3 weeks. For at least 17 days after hatching, all birds behaved like normal chicks, and the grey quail-like feathers were the only manifestations of their chimerism. Initial neurological symptoms of unsteady walking and drooping of the wings were noted in all birds except for 1 that died an accidental death before it became sick. Advanced symptoms characterized by paralysis of the legs forcing the bird to lie on its side were noted in 40 birds. The chimeras could be divided into two groups, each consisting of 24 birds. The short-survival (SS) chimeras of the first group became terminally ill and had to be sacrificed within 3 months. The long-survival (LS) chimeras of the second group showed more protracted disease, in that only 16 of them showed symptoms of the advanced disease, and the majority showed partial or complete recovery. Ten of the LS birds were kept alive for more than 8 months. Furthermore, many LS chimeras lost their grey feathers. The hallmarks of neurohistological manifestations were mononuclear cell infiltrates, demyelinization with preservation of axons and scar formation. These lesions were restricted to the quail fragment of the spinal cord except for 2 birds in which distant cellular infiltrates were observed. Direct immunofluorescence tests for chicken IgG were positive in spinal cords of most SS chimeras but only of some LS chimeras.     

So-called sclerosing hemangioma of the lung--two cases report with ultrastructural study

Sclerosing hemangiomas of the lung are benign neoplasms of uncertain histogenesis. We analysed two cases of sclerosing hemangiomas of the lung with histochemistry and electron microscopy. They had a variegated histologic appearance characterized by an admixture of solid, hemorrhagic, papillary and sclerotic lesions. Characteristic uniform round cells, unique to this tumor, were found within the stroma in all lesions. In the electron microscopic examination, we found Weibel-Palade bodies like small bodies in the tumor cells. We suspect hypothesis originating in the endothelial cell can not be completely excluded yet. Sclerosing hemangioma is a distinct clinicopathologic entity and should be distinguished from other benign neoplasms or inflammatory lesions of the lung.     

Exclusion mapping of 12 X-linked disease loci and 10 DNA probes from the long arm of the X-chromosome

Specific chromosome rearrangements associated with disease entities are invaluable resources for physical mapping. A deletion on the X chromosome of a male leads to the nullisomy for X-linked genes, resulting in the onset of genetic diseases and/or the absence of the DNA probe detectable sequences. This permits the localization of these loci within the deleted area. On the other hand, the region for some other X-linked loci can be excluded from the deleted area according to the absence of the characteristic symptoms of the disease and/or the presence of the hybridization signals. An interstitial deletion on the long arm of the X chromosome of a male has been characterized by high resolution banding. The karyotype of the proband is 46,Y,del(X)(pter----q21.1::q21.33----qter). The regions for 12 X-linked disease loci as well as 10 DNA probes are excluded from the deleted area, and localized either proximally or distally to the deletion. The results also reveal a controversy in the present linkage data concerning the assignment of these loci.     

Non-competitive inhibition of GABA currents by phenothiazines in cultured chick spinal cord and rat hippocampal neurons

The gamma-aminobutyric acid (GABA) inhibiting properties of several classes of antipsychotic medications were studied using gigaseal whole-cell voltage-clamp techniques in cultured chick spinal cord and rat hippocampal neurons. At doses above 1 microM trifluoperazine, chlorpromazine and thioridazine blocked GABA currents in a non-competitive fashion decreasing the maximal transmitter response without altering the half-maximal effective concentration. In contrast, haloperidol was ineffective against GABA at concentrations up to 100 microM. Among the agents studied trifluoperazine was the most potent GABA inhibitor with half maximal effect at 12 microM. Trifluoperazine (100 microM) also inhibited glycine-gated chloride currents in spinal cord neurons to an extent comparable to GABA (85 +/- 6% inhibition) but reduced glutamate currents by less than 35% in either spinal cord or hippocampal neurons.     

c-kit Expression in small cell carcinoma of the urinary bladder: prognostic and therapeutic implications.

The prognosis for small cell carcinoma of the urinary bladder is poor, and strategies for improved therapy are needed. Targeted therapy against the c-kit proto-oncogene has been successful in the management of gastrointestinal stromal tumor. We investigated the expression of c-kit in 52 cases of small cell carcinoma of the urinary bladder. Specimens with more than 10% of cells demonstrating strong membrane staining were considered to have positive immunostaining for c-kit. c-kit expression was detected in 21 of 52 specimens from these patients. Among the 21 specimens, seven had less than 10% staining, and were considered to be negative. Nine had 11-50% staining, and five had more than 50% staining. Overall, 14 of 52 (27%) small cell carcinomas of the urinary bladder were positive for c-kit expression. During a median follow-up of 11 months, 60% of the patients died of bladder cancer. No association was found between c-kit expression and survival or other clinicopathologic parameters. Five-year cancer-specific survivals for c-kit-positive and c-kit-negative tumors were 9 and 15%, respectively (P=0.36). A significant proportion (27%) of small cell carcinomas of the urinary bladder expressed c-kit, suggesting that it may prove useful as a therapeutic target in small cell carcinoma of the urinary bladder.     

Nucleolar localization of non-structural protein 3b, a protein specifically encoded by the severe acute respiratory syndrome coronavirus

The open reading frame 3 (ORF3) of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes a predicted 154-amino acid protein, which lacks similarities to any known protein, and is named 3b. In this study, it was shown that 3b protein was predominately localized to nucleus with EGFP tag at its N- or C-terminus. The localization patterns were similar in different transfected cells. Immuno-fluorescence assay revealed that 3b protein was co-localized well with C23 in nucleolus. C23, B23 and fibrillarin all are important nucleolar proteins, which localize in the region of the nucleolus. Co-transfection of p3b-EGFP with pC23-DsRed, pB23-DsRed and pfibrillarin-DsRed further confirmed 3b's nucleolus localization. With construction of serial truncated mutants of 3b, a region (residues 134-154 aa) responsible for nucleolar localization was determinated in 3b protein. These results provide a new insight for further functional studies of SARS-CoV 3b protein.     

丙型肝炎病毒阳性血清体外感染人肝细胞的研究

目的 研究丙型肝炎病毒(HCV)抗体(Ab)阴性,HCV-RNA阳性血清建立体外感染肝细胞模型.方法 HCV Ab阴性,HCV-RNA阳性的窗口期血清与人肝细胞共同培养,用反转录-聚合酶链反应(RT-PCR)、免疫荧光染色、Western blot、共聚焦显微镜和透射电镜等方法检测细胞内HCV核酸复制、蛋白质表达及超微结构改变.结果 细胞与病毒共同培养7～45 d,细胞内和/或培养上清中可间断检出HCV正、负链RNA;细胞浆内有HCV 核心和NS3抗原的表达;细胞超微结构有改变,并于感染后第24天时观察到类似病毒样颗粒.结论 窗口期血清中的HCV能在人肝细胞7701中复制一段时间.     

Cholesteryl-grafted functional amphiphilic poly(N-isopropylacrylamide-co-N-hydroxylmethylacrylamide): synthesis, temperature-sensitivity, self-assembly and encapsulation of a hydrophobic agent

A thermally responsive amphiphilic grafted copolymer comprised of hydroxyl-containing random poly(N-isopropylacrylamide-co-N-hydroxylmethylacrylamide) as the hydrophilic chain and cholesteryl groups as hydrophobic side arms was developed for the controlled release of hydrophobic drugs. The polymer was temperature-sensitive with a lower critical solution temperature of 40.5 degrees C and a critical micelle concentration of 4 mg/l. Dynamic light-scattering studies showed that the amphiphilic polymer self-assembled into micelles in aqueous media with their mean sizes in the range of 25-34 nm. Transmission electron microscope studies showed that the nanoparticles prepared from the micelle solutions exhibited multiple morphologies including unusual cubic and cuboids-like shapes, and normal spherical shapes, which could be controlled by the formation conditions. Wide-angle X-ray scattering studies showed that these nanoparticles were amorphous in nature but a small crystalline phase existed and the crystallinity of particles increased with the decrease of initial formation concentration. Pyrene was employed as a model hydrophobic agent to examine the encapsulation ability of the polymer with respect to hydrophobic agents in aqueous media. The loading level of the polymer with respect to pyrene was 4.4 mg/g, indicating that the thermally responsive amphiphilic polymer would be able to be used for the encapsulation of hydrophobic drugs.     

Optimization of combined electron and photon beams for breast cancer

Recently, intensity-modulated radiation therapy and modulated electron radiotherapy have gathered a growing interest for the treatment of breast and head and neck tumours. In this work, we carried out a study to combine electron and photon beams to achieve differential dose distributions for multiple target volumes simultaneously. A Monte Carlo based treatment planning system was investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We compared breast treatment plans generated using this home-grown optimization and dose calculation software for different treatment techniques. Five different planning techniques have been developed for this study based on a standard photon beam whole breast treatment and an electron beam tumour bed cone down. Technique 1 includes two 6 MV tangential wedged photon beams followed by an anterior boost electron field. Technique 2 includes two 6 MV tangential intensity-modulated photon beams and the same boost electron field. Technique 3 optimizes two intensity-modulated photon beams based on a boost electron field. Technique 4 optimizes two intensity-modulated photon beams and the weight of the boost electron field. Technique 5 combines two intensity-modulated photon beams with an intensity-modulated electron field. Our results show that technique 2 can reduce hot spots both in the breast and the tumour bed compared to technique 1 (dose inhomogeneity is reduced from 34% to 28% for the target). Techniques 3, 4 and 5 can deliver a more homogeneous dose distribution to the target (with dose inhomogeneities for the target of 22%, 20% and 9%, respectively). In many cases techniques 3, 4 and 5 can reduce the dose to the lung and heart. It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost electron field.