[Study on the risk factors for hemorrhagic transformation of cerebellar infarction after posterior fossa decompression surgery].

Objective: To investigate the related risk factors for hemorrhagic transformation (HT) of cerebellar infarction after posterior fossa decompression surgery. Methods: A total of 91 patients with cerebellar infarction were treated by posterior fossa decompression surgery in Department of Neurosurgery of Jinhua Municipal Central Hospital from Jan 2010 to Jan 2018, were selected as study subjects. The HT group included 17 cases, while the Non-HT group included 74 cases. The clinical data of the two groups were analyzed retrospectively, the univariate and non-conditional lgistic regression analysis were performed to detect the relevant risk factors for hemorrhagic transformation of cerebellar infarction after posterior fossa decompression surgery. Results: By univariate analysis, the differences of these seven risk factors, the large area cerebellar infarction (the diameter of area was larger than 5 cm), pre-op thrombolysis, pre-op mild HT, oral anticoagulants, atrial fibrillation, hyperglycemia and fluctuation of BP in post-op, between two groups were statistically significant (P<0.05). By multivariate logistic analysis, the large area cerebellar infarction (P<0.05), pre-op thrombolysis(P<0.01), pre-op mild HT (P<0.01), oral anticoagulants (P<0.01) were the independent risk factors for post-op HT. Conclusions: The large area cerebellar infarction (the diameter of area was more than 5 cm), pre-op thrombolysis, pre-op mild HT, oral anticoagulants, atrial fibrillation, hyperglycemia and fluctuation of BP in post-op are important risk factors for post-op HT. The large area cerebellar infarction, pre-op thrombolysis, pre-op mild HT, oral anticoagulants are the independent risk factors for post-op HT. A proper pre-op evaluation of these risk factors and an individualized treatment for post-op HT would help a lot with balancing operational risk and improving prognosis.

Leptin regulated calcium channels of neuropeptide Y and proopiomelanocortin neurons by activation of different signal pathways.

The fat-derived hormone leptin regulates food intake and body weight in part by modulating the activity of neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons in the hypothalamic arcuate nucleus (ARC). To investigate the electrophysiological activity of these neurons and their responses to leptin, we recorded whole-cell calcium currents on NPY and POMC neurons in the ARC of rats, which we identified by morphologic features and immunocytochemical identification at the end of recording. Leptin decreased the peak amplitude of high voltage-activated calcium currents (I(HVA)) in the isolated neurons from ARC, which were subsequently shown to be immunoreactive for NPY. The inhibition was prevented by pretreatment with inhibitors of Janus kinase 2 (JAK2) and mitogen-activated protein kinases (MAPK). In contrast, leptin increased the amplitude of I(HVA) in POMC-containing neurons. The stimulations of I(HVA) were inhibited by blockers of JAK2 and phosphatidylino 3-kinase (PI3-k). Both of these effects were counteracted by the L-type calcium channel antagonist nifedipine, suggesting that L-type calcium channels were involved in the regulation induced by leptin. These data indicated that leptin exerted opposite effects on these two classes of neurons. Leptin directly inhibited I(HVA) in NPY neurons via leptin receptor (LEPR) -JAK2-MAPK pathways, whereas evoked I(HVA) in POMC neurons by LEPR-JAK2-PI3-k pathways. These neural pathways and intracellular signaling mechanisms may play key roles in regulating NPY and POMC neuron activity, anorectic action of leptin and, thereby, feeding.

Complete regression of well-established tumors using a novel water-soluble poly(L-glutamic acid)-paclitaxel conjugate.

Despite an intensive search, few water-soluble paclitaxel derivatives have been shown to have a therapeutic index superior to paclitaxel itself. We now report a water-soluble poly(L-glutamic acid)-paclitaxel conjugate (PG-TXL) that produces striking antitumor effects with diminished toxicity. A single i.v. injection of PG-TXL at its maximum tolerated dose (defined as that dose that produces a maximum 12-15% body weight loss within 2 weeks after a single i.v. injection) equivalent to 60 mg of paclitaxel/kg and at even a lower dose equivalent to 40 mg of paclitaxel/kg resulted in the disappearance of an established implanted 13762F mammary adenocarcinoma (mean size, 2000 mm3) in rats. (An equivalent dose of PG-TXL is the amount of conjugate that contains the stated amount of paclitaxel.) Similarly, mice bearing syngeneic OCA-1 ovarian carcinoma (mean size, 500 mm3) were tumor-free within 2 weeks after a single i.v. injection of the conjugate at a dose equivalent to 160 mg of paclitaxel/kg. The conjugate has little if any intrinsic tubulin polymerization activity in vitro and is >20 times less potent in supporting the growth of a paclitaxel-dependent CHO mutant cell line. PG-TXL has a prolonged half-life in plasma and greater uptake in tumor as compared with paclitaxel. Furthermore, only a small amount of total radioactivity from PG-[3H]TXL was recovered as free [3H]paclitaxel in either the plasma or the tumor tissue within 144 h after drug injection. Histological studies of tumor tissues obtained from mice treated with PG-TXL show fewer apoptotic cells but more extensive tumor necrosis as compared with paclitaxel treatment. These data suggest that in addition to its role as a carrier for selective delivery of paclitaxel to the tumor, PG-TXL exerts distinct pharmacological actions of its own that may contribute to its remarkable antitumor efficacy.

Antitumor activity of poly(L-glutamic acid)-paclitaxel on syngeneic and xenografted tumors.

Poly(L-glutamic acid)-paclitaxel (PG-TXL) is a new water-soluble paclitaxel derivative that has shown remarkable antitumor activity against both ovarian and breast tumors. The purpose of this study was to test whether the antitumor efficacy of PG-TXL depends on tumor type, as is the case for paclitaxel, and to test whether paclitaxel-resistant tumors could be responsive to PG-TXL. We evaluated the therapeutic activity of PG-TXL against four syngeneic murine tumors (MCa-4, MCa-35, HCa-1, and FSa-II) inoculated i.m. into C3Hf/Kam mice, a human SKOV3ip1 ovarian tumor injected i.p. into nude mice, and a human MDA-MB-435Lung2 breast tumor grown in the mammary fat pad of nude mice. Two paclitaxel-responsive murine tumors, MCa-4 and MCa-35, showed significant growth delay with PG-TXL given as a single i.v. injection at its maximum tolerated dose of 160 mg of equivalent paclitaxel/kg or even at a lower dose of 120 mg of equivalent paclitaxel/kg. The other two murine tumors, HCa-1 and FSa-II, did not respond particularly well to either of the two agents, although significant growth delay was observed for both tumors with PG-TXL. In mice with SKOV3ip1 tumors, the median survival times for mice treated with PG alone and PG-TXL at doses of 60 or 120 mg of equivalent paclitaxel/kg were 43, 61, and 75 days, respectively; no survival difference was found between paclitaxel-treated and Cremophor vehicle-treated mice. In mice with MDA-MB-435Lung2 tumor, PG-TXL at a dose of 120 mg of equivalent paclitaxel/kg produced regression of the tumor in 50% of the animals, and in the remaining mice, micrometastases in the lung were found only in 25% of the animals. In comparison, treatment with paclitaxel at 60 mg/kg did not result in tumor regression, and the rate of lung metastases was 42%. These results clearly demonstrate that PG-TXL has significant therapeutic activity against breast and ovarian tumors tested in this study. Future studies to elucidate the mechanism of action of PG-TXL and to assess its clinical applications are warranted.

Synthesis, biodistribution and imaging properties of indium-111-DTPA-paclitaxel in mice bearing mammary tumors.

UNLABELLED: Paclitaxel, an antineoplastic agent that stabilizes microtubules and arrests cells in the G2/M cell cycle phase, has shown activity against many common cancers, including ovarian and breast tumors. In order to evaluate the potential value of radiolabeled paclitaxel as an imaging tool in tumors, we synthesized 111In-DEPA-paclitaxel and investigated its biodistribution and gamma scintigraphic imaging properties. METHODS: Mice bearing a paclitaxel-responsive mammary tumor (MCA-4) were used. DTPA-paclitaxel was labeled with 111In with a radiochemical yield of 84% and radiochemical purity of 90%. Each mouse received 5 microCi of radiotracers intravenously for biodistribution studies and 100 microCi for gamma scintigraphic studies. Indium-111-DTPA was used as a control. RESULTS: In tumor-bearing mice, 111In-DTPA was characterized by rapid clearance from the plasma with negligible retention in the tumor, the liver and other body parts. In contrast, 111In-DTPA-paclitaxel exhibited a pharmacological profile resembling that of paclitaxel. Furthermore, a significant uptake of 111In-DTPA-paclitaxel was observed in the tumor. The tumor-to-muscle ratios were 2.64, 3.16 and 6.94 at 30 min, 2 hr and 24 hr, respectively, although absolute uptake in the tumor decreased from 1.95% (injected dose/g) at 30 min to 0.21% at 24 hr after injection. The tumor-to-blood ratio reached 50 at 24 hr after injection. Gamma scintigraphy and autoradiographic studies clearly showed the retention of radiolabeled paclitaxel in the tumor 24 hr after injection. CONCLUSION: These studies suggest that 111In-DTPA-paclitaxel may be clinically useful in studying the uptake of paclitaxel in solid tumors.

Maximum-likelihood transmission image reconstruction for overlapping transmission beams.

In many transmission imaging geometries, the transmitted "beams" of photons overlap on the detector, such that a detector element may record photons that originated in different sources or source locations and thus traversed different paths through the object. Examples include systems based on scanning line sources or on multiple parallel rod sources. The overlap of these beams has been disregarded by both conventional analytical reconstruction methods as well as by previous statistical reconstruction methods. We propose a new algorithm for statistical image reconstruction of attenuation maps that explicitly accounts for overlapping beams in transmission scans. The algorithm is guaranteed to monotonically increase the objective function at each iteration. The availability of this algorithm enables the possibility of deliberately increasing the beam overlap so as to increase count rates. Simulated single photon emission tomography transmission scans based on a multiple line source array demonstrate that the proposed method yields improved resolution/noise tradeoffs relative to "conventional" reconstruction algorithms, both statistical and nonstatistical.

Paclitaxel and water-soluble poly (L-glutamic acid)-paclitaxel, induce direct chromosomal abnormalities and cell death in a murine metastatic melanoma cell line.

The purpose of this study was to demonstrate the effects of paclitaxel and water-soluble poly (L-glutamic acid)-paclitaxel (PG-TXL), on chromosome morphology, telomeric associations, and induction of cell death in a murine melanoma cell line (K-1735 clone X-21). Murine melanoma cells were treated with various concentrations (0.1 microgram, 1.0 microgram, 4.0 micrograms, and 8.0 micrograms/ml) of paclitaxel alone, PG alone, or PG-TXL for 2 hr and 4 hr and harvested immediately without recovery. We found that: (1) the frequency of metaphases with telomeric associations increased, (2) metaphases had clumped and distorted chromosome morphology, (3) cells accumulated in metaphase (mitotic arrest), and (4) cell death had been induced. Cells treated with PG-TXL showed more such abnormalities than did cells treated with either paclitaxel or PG alone. Our preliminary results indicate that PG-TXL may be superior to paclitaxel alone in inducing cytotoxic effects, and these effects could be mediated by various chromosomal abnormalities in cancer cells.

Mean and variance of single photon counting with deadtime.

The statistics of photon counting by systems affected by deadtime are potentially important for statistical image reconstruction methods. We present a new way of analysing the moments of the counting process for a counter system affected by various models of deadtime related to PET and SPECT imaging. We derive simple and exact expressions for the first and second moments of the number of recorded events under various models. From our mean expression for a SPECT deadtime model, we derive a simple estimator for the actual intensity of the underlying Poisson process; simulations show that our estimator is unbiased even for extremely high count rates. From this analysis, we study the suitability of the Poisson statistical model assumed in most statistical image reconstruction algorithms. For systems containing 'modules' with several detector elements, where each element can cause deadtime losses for the entire module, such as block PET detectors or Anger cameras, the Poisson statistical model appears to be adequate even in the presence of deadtime losses.

In vivo and in vitro measurement of apoptosis in breast cancer cells using 99mTc-EC-annexin V.

OBJECTIVE: The purpose of this study was to develop an imaging technique to measure and monitor tumor cells undergoing programmed death caused by radiation and chemotherapy using 99mTc-EC-annexin V. Annexin V has been used to measure programmed cell death both in vitro and in vivo. Assessment of apoptosis would be useful to evaluate the efficacy and mechanisms of therapy and disease progression or regression. METHODS: Ethylenedicysteine (EC) was conjugated to annexin V using sulfo-N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-HCl as coupling agents. The yield of EC-annexin V was 100%. In vitro cellular uptake, pre- and post-radiation (10-30 Gy) and paclitaxel treatment, was quantified using 99mTc-EC-annexin V. Tissue distribution and planar imaging of 99mTc-EC-annexin V were determined in breast tumor-bearing rats at 0.5, 2, and 4 hrs. To demonstrate in vivo cell apoptosis that occurred during chemotherapy, a group of rats was treated with paclitaxel and planar imaging studies were conducted at 0.5-4 hrs. Computer outlined region of interest (ROI) was used to quantify tumor uptake on day 3 and day 5 post-treatment. RESULTS: In vitro cellular uptake showed that there was significantly increased uptake of 99mTc-EC-annexin V after irradiation (10-30 Gy) and paclitaxel treatment. In vivo biodistribution of 99mTc-EC-annexin in breast tumor-bearing rats showed increased tumor-to-blood, tumor-to-lung and tumor-to-muscle count density ratios as a function of time. Conversely, tumor-to-blood count density ratios showed a time-dependent decrease with 99mTc-EC in the same time period. Planar images confirmed that the tumors could be visualized clearly with 99mTc-EC-annexin. There was a significant difference of ROI ratios between pre- and post-paclitaxel treatment groups at 2 and 4 hrs post injection. CONCLUSION: The results indicate that apoptosis can be quantified using 99mTc-EC-annexin and that it is feasible to use 99mTc-EC-annexin to image tumor apoptosis.

[Structure revision of triptophenolide].

A diterpenoid-lactone, white thin crystals, C20H24O3, m/z: 312 (M+), mp 222-223 degrees C, UV lambda max (EtOH) 217 (log epsilon 4.36) nm, has been isolated from the ethyl acetate extract of the roots of Tripterygium wilfordii Hook. f., in a yield of 0.025%. Its structure was elucidated by spectral analysis (UV, IR, MS, 1HNMR and 13CNMR) and X-ray SCD. It is the known triptophenolide with revision of structure. Triptophenlolide was shown to have obvious inhibiting effects on lymphocyte and IgG (P less than 0.01) when mice and rats were given ig 1.5 mg/kg. The total complements in blood serum was increased. When BALB/C mice were given ig 1.5 mg/kg, the ear oedema induced by dimethyl benzene was significantly inhibited (P less than 0.01); The ear oedema induced by croton oil in SD rats at a dose of ig 1.0 mg/kg was also significantly inhibited (P less than 0.05). The vitamin C content of the adrenal gland was reduced in mice at a dose of 1.5 mg/kg. The ig LD50 of triptophenolide was greater than 30 mg/kg.

MUC19 expression in human ocular surface and lacrimal gland and its alteration in Sjögren syndrome patients.

This study investigated the expression of MUC19, a newly discovered gel-forming mucin gene, in normal human lacrimal functional unit components and its alteration in Sjögren syndrome patients. Real-time PCR and immunohistochemistry were performed to determine the expression of MUC19 and MUC5AC in human cornea, conjunctiva, and lacrimal gland tissues. Conjunctival impression cytology specimens were collected from normal control subjects and Sjögren syndrome patients for Real-time PCR, PAS staining, and immunohistochemistry assays. In addition, conjunctiva biopsy specimens from both groups were examined for the expression differences of MUC19 and MUC5AC at both mRNA and protein level. The MUC19 mRNA was found to be present in cornea, conjunctiva and lacrimal gland tissues. The immunohistochemical staining of mucins showed that MUC19 was expressed in epithelial cells from corneal, conjunctival, and lacrimal gland tissues. In contrast, MUC5AC mRNA was only present in conjunctiva and lacrimal gland tissues, but not in cornea. Immunostaining demonstrates the co-staining of MUC19 and MUC5AC in conjunctival goblet cells. Consistent with the significant decrease of mucous secretion, both MUC19 and MUC5AC were decreased in conjunctiva of Sjögren syndrome patients compared to normal subjects. Considering the contribution of gel-forming mucins to the homeostasis of the ocular surface, the decreased expression of MUC19 and MUC5AC in Sjögren syndrome patients suggested that these mucins may be involved in the disruption of the ocular surface homeostasis in this disease.

Synthesis of [99mTc]ethylenedicysteine-colchicine for evaluation of antiangiogenic effect.

Angiogenesis is in part responsible for tumor growth and the development of metastasis. Radiolabeled angiongenesis inhibitors would be useful to assess tumor microvasculature density. Colchicine (COL), a potent antiangiogenic agent, is known to inhibit microtubule polymerization and cell arrest at metaphase. This study aimed to develop 99mTc-labeled COL (EC-COL) using ethylenedicysteine (EC) as a chelator to assess tumor microvascular density. EC was conjugated to trimethylcolchicinic acid using N-hydroxysuccinimide and 1-ethyl-3-dimethylaminopropyl carbodiimide as coupling agents with a yield of 50-60%. In vivo stability was analyzed in rabbit serum at 0.5-4 h. Tissue distribution and planar imaging studies of [99mTc]EC-COL were evaluated in breast tumor-bearing rats at 0.5, 2 and 4 h. The data was compared to that using [99mTc]EC (control). The radiochemical yield of [99mTc]EC-COL was greater than 95%. [99mTc]EC-COL was stable in rabbit serum. In vivo biodistribution of [99mTc]EC-COL in breast tumor-bearing rats showed increased tumor-to-blood (0.52+/-0.12 to 0.72+/-0.07) and tumor-to-muscle (3.47+/-0.40 to 7.97+/-0.93) ratios as a function of time. Conversely, tumor-to-blood values showed a time-dependent decrease with [99mTc]EC over the same time period. Planar images confirmed that the tumors could be visualized clearly with [99mTc]EC-COL from 0.5 to 4 h. [99mTc]EC-COL may be useful to assess antiangiogenic and therapeutic effects during chemotherapy.