A glutathione-responsive photosensitizer with fluorescence resonance energy transfer characteristics for imaging-guided targeting photodynamic therapy.

Here, we have synthesized and characterized a novel activatable photosensitizer (PS) 8a in which two well-designed boron dipyrromethene (BODIPY) derivatives are utilized as the photosensitizing fluorophore and quencher respectively, which are connected by a disulfide linker via two successive Cu (І) catalyzed click reactions. The fluorescence emission and singlet oxygen production of 8a are suppressed via intramolecular fluorescence resonance energy transfer (FRET) from the excited BODIPY-based PS part to quencher unit, but both of them can be simultaneously switched on by cancer-related biothiol glutathione (GSH) in phosphate buffered saline (PBS) solution with 0.05% Tween 80 as a result of cleavage of disulfide. Also, 8a exhibits a bright fluorescence image and a substantial ROS production in A549 human lung adenocarcinoma, HeLa human cervical carcinoma and H22 mouse hepatoma cells having a relatively high concentration of GSH, thereby leading to a significant photocytotoxicity, with IC50 values as low as 0.44 µM, 0.67 µM and 0.48 µM, respectively. In addition, the photosensitizer can be effectively activated and imaged in H22 transplanted hepatoma tumors of mice and shows a strong inhibition on tumor growth. All these results suggest that such a GSH-responsive photosensitizer based on FRET mechanism may provide a new strategy for tumor-targeted and fluorescence imaging-guided cancer therapy.

[Experiences of transcallosal-interforniceal approach for resection of the third ventricle and the pineal region tumors: report of 24 cases].

OBJECTIVE: To discuss the advantages and disadvantages of transcallosal-interforniceal approach for resection of the third ventricle and the pineal region tumors. METHODS: The clinical data of 24 cases from July 2008 to March 2011 were retrospectively analyzed. All 24 patients operated by transcallosal-interforniceal approach, among them, there were 14 males and 10 females, with a average age of 32 years ranged from 17 to 65 years and with medical history from 1 month to 10 years. Issues of managements were analyzed and discussed, including reasonable incision design, the managements of draining vein, the site and the length of the incision of the corpus callosum, tumor exposure in increased intracranial pressure, prevention of complications, skills of surgery, treatments of obstructive hydrocephalus, and postoperative managements. RESULTS: In the 24 cases, there were 5 cases of pineal parenchymal tumors, 4 cases of germinoma, 3 cases of astrocytoma, 2 cases of hypothalamus hamartomas, 2 cases of ependymoma, 2 cases of mixed germ cell tumour, 2 cases of malignant lymphomas, 1 case of pineoblastoma, 1 case of dermoid cyst, 1 case of chordoid glioma and 1 case of craniopharyngioma. After surgeries, total removal achieved in 9 cases, and subtotal removal in 10 cases and partial removal in 5 cases. Operative mortality was 0. Combined third ventriculostomy were performed in 13 cases. Postoperative complications occurred in 5 cases, including frontoparietal epidural hematoma in 1 case; postoperative short-term memory loss in 3 cases, postoperative memory loss within 1 month in 2 cases and within 3 months in 1 case; frontoparietal subdural effusion in 1 case and the effusion disappeared without any treatment. Ventriculoperitoneal shunt was performed in 1 case. CONCLUSIONS: The transcallosal-interforniceal approach is ideal for the removal of tumors in third ventricle as well as majority tumor in posterior of third ventricle in a skillful hand. Tumor resection combined with third ventriculostomy is the significant advantages in the approach.

New species of the isolated Psaroniaceous rachis from the Early Permian in China.

A new kind of marattialean raches are reported from the coal balls in Coal Seam No.7 in the upper part of the Taiyuan Formation (early Early Permian) from Taiyuan, Shanxi, China and are assigned to the genus Stipitopteris Grand'Eury (Psaroniaceae). The present specimens are different from all six reported species of the genus, and are therefore proposed as a new species: Stipitopteris shanxiensis. The raches of the new species are generally dorsi-ventrally flattened. The main raches usually exhibit scales of different forms on their surface. Beneath the epidermis is a zone of parenchymatous cells, some of which contain tannin-like contents. Inside this is a zone of small sclerenchymatous cells. Inward are the ground tissue and vascular bundles. The vascular bundles are continuous and are in two circles: the outer circle assumes a transversely elliptical shape with the gap and pinna trace, and the inner circle assumes a shallow C-shape with inrolled ends. The ground tissue located at the inner side of the vascular bundle is composed of thicker-walled parenchymatous cells. The cells of the ground tissue are vertically elongated in longitudinal sections. Subordered raches are smaller and have simpler structures than the main raches. The parenchyma zone beneath the epidermis is thinner, usually one to two cells wide and the sclerenchyma zone is usually absent. The scales are poorly developed and there is only one C-shaped vascular bundle. The new species is comparable to the crosiers of Psaroniaceae of the Euramerican Flora in some aspects, for example, it has a dorsi-ventrally flattened rachis and scales on the surface of the rachis. However, the other features and the preservative conditions of the present specimens indicate that they are not crosiers, but fully developed or mature raches. The new species is the first well-studied anatomically-preserved rachis of Psaroniaceae from the Cathaysian Flora and bears significance not only in understanding the anatomy and taxonomy of Psaroniaceae in the Cathaysian Flora, but also in the relationship between the Euramerican Flora and the Cathaysian Flora.

Management of intracranial invasive olfactory neuroblastoma.

BACKGROUND: Olfactory neuroblastoma (ONB) is a rare tumor that often arise from the nasal cavity. The aim of this study was to investigate the clinical characteristics and treatments of intracranial invasive ONB. METHODS: Between July 2001 and August 2005, 5 patients with intracranial invasive ONB were treated in our department. Their clinical features, radiological and pathological characteristics, and surgical treatments were analyzed. Among the 5 patients, 1 received transnasal biopsy, and 4 were operated through the transfrontal or extended bifrontal approaches to reconstruct the skull base. After the operation, all the patients received radiotherapy, and one received chemotherapy. They were followed up for 6 to 45 months. RESULTS: The ONB was resected totally in the 4 patients. In all the patients, nasal obstruction was alleviated without cerebrospinal fluid leakage. The visual acuity was improved in 3 patients, who had a decreased visual acuity before the operation. Two patients had metastasis into the lumbosacral spinal canal 6 and 8 months after the operation, one of them received a second operation and the other died. CONCLUSION: ONB has no specific symptoms. Intracranial ONB should be resected as far as possible, and treated by radiotherapy after the operation.

[Myxoma of cranial base: study of 23 cases].

OBJECTIVE: To study the clinical manifestations and diagnosis and treatment of cranial base myxoma. METHODS: The clinical data of 23 cases of myxoma of cranial base confirmed by pathology from Oct. 1983 to Nov. 2005, 14 males and 9 females, aged 32.7 (18 approximately 50), were analyzed retrospectively. Operation was performed on all 23 patients, 8 cases underwent radiotherapy postoperatively. 11 patients were followed up after operation for 64.5 month. RESULTS: Most of the tumors were located in the parasellar and middle fossa and jugular region. The clinical manifestations included headache and injury of multiple cranial nerves. Imaging examination showed calcification and osseous elements in the center of tumor. The approaches of operation were selected according to the tumor position. Subtotal resection was achieved in 16 cases, and gross resection in 7 cases. The condition was improved postoperatively in 2 cases, unchanged in 11 cases, and aggravated in 9 cases, of which one died. The follow up showed that recuperation was achieved in 6 cases, recurrence occurred in 4 cases, and 1 patient died. CONCLUSION: It is hard to remove the total myxoma of cranial base. The curative efficacy of radiotherapy is not definite. The important substance of the myxoma is mucus. It is difficult to differentiate myxoma from chondrogenic tumor and chordoma in cranial base by the clinical and neuroradiological manifestations.