Biofilm Formation Characteristics of Pseudomonas lundensis Isolated from Meat.

Biofilms formations of spoilage and pathogenic bacteria on food or food contact surfaces have attracted increasing attention. These events may lead to a higher risk of food spoilage and foodborne disease transmission. While Pseudomonas lundensis is one of the most important bacteria that cause spoilage in chilled meat, its capability for biofilm formation has been seldom reported. Here, we investigated biofilm formation characteristics of P. lundensis mainly by using crystal violet staining, and confocal laser scanning microscopy (CLSM). The swarming and swimming motility, biofilm formation in different temperatures (30, 10, and 4 °C) and the protease activity of the target strain were also assessed. The results showed that P. lundensis showed a typical surface-associated motility and was quite capable of forming biofilms in different temperatures (30, 10, and 4 °C). The strain began to adhere to the contact surfaces and form biofilms early in the 4 to 6 h. The biofilms began to be formed in massive amounts after 12 h at 30 °C, and the extracellular polysaccharides increased as the biofilm structure developed. Compared with at 30 °C, more biofilms were formed at 4 and 10 °C even by a low bacterial density. The protease activity in the biofilm was significantly correlated with the biofilm formation. Moreover, the protease activity in biofilm was significantly higher than that of the corresponding planktonic cultures after cultured 12 h at 30 °C.

[Depth of focus in spherical and aspheric intraocular lenses].

OBJECTIVE: To investigate depth of focus (DOF) in spherical and aspheric IOL eye models. METHODS: Computer numerical simulation experiment was used. IOL eye model based on Liou-Brennan eye model was constructed by using ZEMAX optical design software. Different IOL were implanted in this eye model. Monochromatic through focus modulation transfer function (MTF) curves were computed. Pupil and aspheric designs' effect on DOF were analyzed. RESULTS: DOF of eye model increased with pupil shrinkage in 550 nm monochromatic light (FY60AD 1.20 D at 6 mm pupil, 1.35 D at 5 mm pupil, 1.70 D at 4 mm pupil, 2.46 D at 3 mm pupil; YA60BBR 1.24 D at 6 mm pupil, 1.48 D at 5 mm pupil, 1.80 D at 4 mm pupil, 2.50 D at 3 mm pupil). MTF in spherical IOL eye model was higher with minus defocus, this trend was obvious at larger pupil. MTF of aspheric IOL eyes were higher than spherical IOL eyes when well focused at 5 mm pupil, while the DOF was lower in aspheric IOL with negative spherical aberration (Tecnis Z9000 1.31 D, FY60AD 1.35 D, CeeOn911 1.55 D, YA60BBR 1.48 D). DOF decreased less in aspheric IOL with zero spherical aberration (LI61AO 1.42 D). CONCLUSIONS: DOF in IOL eye model was higher at smaller pupil. When the pupil was large, well focused aspheric IOL improved optical quality compared with spherical IOL, while DOF and the tolerance to defocus in aspheric IOL were partially lost; this phenomenon was obvious with minus defocus.

Antitumor effects of recombinant human interleukin-6 on mouse bladder carcinoma through Fas-mediated apoptosis.

PURPOSE: An apoptosis-inducing therapy is gradually becoming a new strategy for cancer treatment. The aim of this study was to investigate the mechanism of growth-inhibitory effects of recombinant human interleukin-6 (rhIL-6) on bladder tumor-bearing T739 mice in vivo. METHODS: Murine bladder transitional carcinoma cells (BTT739) were inoculated subcutaneously into T739 mice as a tumor model for evaluating the antitumor effects of rhIL-6. Then the mice were divided randomly into 5 groups: A, B, C, D and E. Different doses (0, 2, 4, 8 x 10(6) IU/kg body weight) of rhIL-6 were injected intraperitoneally twice per day and administered for 14 days, and 1 mg/kg/d mitomycin-C(MMC) was used as control. Tumor size was measured and determined as the mean of the largest diameter and the diameter at right angle. Animals were killed by CO(2) inhalation on the 15th day after tumor cell inoculation. Then, tumors were removed, weighed and collected. The tumor growth inhibition rate of rhIL-6 was calculated. The morphological characteristic changes of tumor cells were observed under electron microscope, and cell cycle analysis was determined by flow cytometry. The expressions of Fas, FasL and Bcl-2 protein on tumor cells were qualitatively detected by immunofluorescence cell staining, and their relative contents (rate of positive cells, RPC) were quantitatively determined with flow cytometry. RESULTS: rhIL-6 could inhibit bladder tumor growth in a dose-dependent manner in vivo. The tumor growth-inhibitory rates of 2, 4, 8 x 10(6) IU/kg rhIL-6 and 1 mg/kg MMC were 11.8, 39.5, 39.7 and 68.8%, respectively. Flow cytometry results showed that a hypodiploid peak before G1 phase could be found in tumor cells treated with rhIL-6. Moreover, the cells treated with rhIL-6 displayed disappearance of nucleoli, chromatin gathering under the nuclear membrane in mass or ring-shape under transmission electron microscopy. The rates of Fas, FasL protein-positive cells estimated by flow cytometry in rhIL-6-treated mice were (12.57 +/- 0.83) and (20.1 +/- 0.87) %, respectively, significantly higher than that (4.66 +/- 0.17) and (14.1 +/- 0.83) % in control mice (P < 0.01). There was no significant difference in the rate of Bcl-2 protein-positive cells between the mice in these two groups (P > 0.05). CONCLUSIONS: rhIL-6 had obvious antitumor effects on mouse bladder carcinoma in vivo, and the Fas signaling pathway might play an important role in rhIL-6-induced bladder carcinoma cell apoptosis.

[Effects of Liuweidihuang Decoction on cell proliferation and melanin synthesis of cultured human melanocytes in vitro].

OBJECTIVE: To investigate the effects of Liuweidihuang Decoction on the proliferation and melanin synthesis of cultured human melanocytes in vitro. METHODS: MTT assay was used to assess the proliferation of cultured human melanocytes after treatment with Liuweidihuang Decoction, and NaOH assay was employed to determine melanin synthesis. RESULTS: Liuweidihuang Decoction at the concentration of 5%-15% did not affect the proliferation of the melanocytes (P>0.05), and the decoction at 20%-30% significantly inhibited the cell proliferation, especially at the optimal concentration of 30% (P<0.01). The decoction promoted melanin synthesis in the melanocytes at the concentration of 10%-15% with the optimal concentration of 15% (P<0.01) but failed to produce such an effect at 20%-30%. CONCLUSION: Liuweidihuang Decoction exert a two-way regulation on the proliferation and melanin synthesis of cultured human melanocytes in vitro.

[A comparison of curative effects of percutaneous nephrostomy and open surgery in the management of postrenal acute renal failure].

OBJECTIVE: To investigate the effects and clinical value of percutaneous nephrostomy (PCN) in the management of postrenal acute renal failure (PARF). METHODS: The clinical data of 40 cases of PARF for the treatment of PCN and 20 cases with open surgery were retrospectively analyzed. RESULTS: The success rate of PCN was 100%, renal function of all patients was restored to normal range after 2-7 days of PCN, in whom 30 patients recovered. In 10 patients nephrostomy was prolonged, among them 2 patients had recurrent abdominal tumors, and 8 patients had cervical cancer in late phase. There was no death, and no complications except hematuria. In the open surgery group, renal function of 19 cases recovered to normal range after 2-7 days of drainage. Lung infection occurred in 3 patients after operation, and they recovered with antibiotic therapy. One patient died of multiple organ dysfunction failure (MOF). CONCLUSION: For PARF, PCN is preferable because of minimal trauma, less blood loss, as well as rapid recovery and better effect on recovery of renal function.

[Relationships between tumor shrinkage and peripheral blood cell changes during tumor-rejection induced by a high dose of 5-FU in C57BL/6 mice].

AIM: To investigate the relationship between the alterations of complete blood counts and tumor shrinkage during tumor rejection induced by a high dose of 5-FU in C57BL/6 mice. METHODS: Wild type C57BL/6 tumor-bearing mice were treated with different doses of 5-FU intraperitoneally. 75 mg/kg 5-FU was the minimal effective dose of 5-FU that could cure the tumor-bearing mice. Then another 6 tumor-bearing mice were treated intraperitoneally with 5-FU (75 mg/kg). Blood samples were obtained from orbital venous sinus on different days before and after 5-FU treatment, and then complete blood counts were performed and the relationship between the alterations of blood counts and tumor shrinkage after 5-FU treatment was analyzed. RESULTS: Tumor sizes decreased steadily and tumors disappeared within the first week after 5-FU treatment; and at the same time 75 mg/kg 5-FU also had side effects on peripherial blood cells. The number of WBC significantly decreased from the first day after 5-FU treatment (P<0.001). But during the 7 th to 15 th day the number of WBC rebounced back to normal level (P>0.05). Later it decreased again and it couldn't recover back to normal level at the 28th day after 5-FU treatment (P<0.01). The concentration of Hb decreased at the first day and lasted for 2 weeks (P<0.01). It increased gradually back to normal in 2 weeks after 5-FU treatment. The inhibitory effect of 5-FU on platelets count was not obvious. The platelet count increased significantly at the first and at the 11th day after 5-FU treatment respectively (P<0.01). CONCLUSION: Tumor shrinkage after 5-FU treatment is not related to the decreased number of WBC or RBC, but correlated with the increased number of platelet at the first day after 5-FU treatment.

[Relationship between sensitivity of tumor cells to chemotherapeutic agent in vivo and in vitro: experiment with mouse lymphoma cells].

OBJECTIVE: To study the relationship of the sensitivity of tumor cells to chemotherapeutic agent between in vivo and in vitro. METHODS: Mouse lymphoma cells of the line E14 were cultured and melphalan resistant EL4 cell line (EL4/melphalan) was established by culturing EL4 cells with continuous low-concentration and intermittent gradually-increasing-concentration of melphalan in vitro. MTT assay was used to evaluate the drug sensitivity and the resistance index of the EL4/melphalan cells to melphalan was calculated. EL4/melphalan and EL4 cells of the concentration of 5 x 10(8)/L were inoculated separately into 20 C57BL/6 mice subcutaneously. 12 days later, the EL4 and EL4/melphalan tumor-bearing mice were randomly divided into 2 groups respectively, 5 mice in each group. Treatment groups were given 7.5 mg/kg melphalan intraperitoneally, and control groups were given the same volume of normal saline. The tumor size was observed every other day. RESULTS: Compared with the EL4 cells, the EL4/melphalan cells had no obvious changes morphologically. They could grow in RPMI 1640 medium containing 5 mg/ml melphalan. The resistance index was 2.87 against melphalan. After the treatment of melphalan of the dose 7.5 mg/kg, the tumor sizes of the treatment groups and control groups inoculated with both EL4 cells and the EL4/melphalan cells gradually decreased at the similar speed, and about one week later all tumors disappeared. However, the tumors of the control groups grew progressively and all the mice died at last. CONCLUSION: The chemotherapeutic effects of tumors in vivo have nothing to do with the effects of the chemotherapeutic agents on tumor cells in vitro. The tumor cells resistant to melphalan in vitro remain sensitive to the drug in vivo.

[Evaluation of absolute alcohol treatment for renal cyst with percutaneous puncture and catheterization under ultrasonographic guidance].

OBJECTIVE: To evaluate the effect of absolute alcohol treatment for renal cyst with percutaneous puncture and catheterization. METHODS: This report presented 64 cases of renal cysts, 34 cases were treated with percutaneous puncture (A group) and 30 cases with percutaneous catheterization (B group). According to the size, the cysts were divided into 2 groups, more than 6 cm in diameter and less than 6 cm in diameter. RESULTS: All the patients were followed up for 3 - 12 months by CT or B ultrasonography. Striking difference of the therapeutic results were existed when cystS were more than 6 cm in diameter. CONCLUSION: Percutaneous catheterization is applicable to the sclerosing treatment of renal cyst whose diameter is more than 6 cm.

Optimal margin in nephron-sparing surgery for renal cell carcinoma 4 cm or less.

OBJECTIVE: Renal cell carcinoma (RCC) of 4 cm or less is with a low incidence of multicentricity and metastasis and is usually considered suitable for nephron-sparing surgery (NSS). This study was designed to investigate the distance between extra-pseudocapsule cancer lesions and primary tumors, and to suggest the optimal margin of normal parenchyma in NSS for RCC 4 cm or less. METHODS: We prospectively studied 82 kidneys in which RCCs of 4 cm or less were resected by radical nephrectomy. According to UICC TNM classification (1997), all tumors were staged as T1 and classified as conventional RCC in 76 cases and papillary RCC in 6 cases. The kidney samples were first step sectioned at 3mm intervals and examined for multicentricity. Then, on each layer of tissue sectioned, parenchyma margins of 15 mm beyond pseudocapsule were continuously sectioned and examined microscopically to investigate completeness of pseudocapsule and possible presence of extra-pseudocapsule cancer lesions. The greatest distance between extra-pseudocapsule lesions and primary tumors was measured. RESULTS: The diameter of 82 primary tumors was 3.4+/-0.7 mm (range 1.5-4.0 cm). Of them, 31.7% (26/82) were found without intact pseudocapsule. Of the 82 cases, 19.5% (16/82) were with positive cancer lesions beyond pseudocapsule, with invasion into normal parenchyma in 12.2% (10/82), into venule in 2.4% (2/82) and satellite tumors in 4.9%(4/82). The average distance between extra-pseudocapsule cancer lesions and primary tumors was 0.5+/-1.3mm (range 0-5.0mm), with a 95% confidential interval (CI) (0.11, 0.94). No significant difference was found in the incidence of extra-pseudocapsule cancer lesions between the tumors 2.5 cm or less and that greater than 2.5 cm. CONCLUSIONS: These data suggest that when partial nephrectomy is performed in RCC 4 cm or less, a 10mm margin may be too large and go against renal function maintaining. Enucleation alone was associated with a significant risk of incomplete excision, and therefore liable for local recurrence. Thorough inspection of the whole kidney before and during operation may help to avoid leaving over large and distant multifocal lesions.

[Optimal margin in nephron-sparing surgery for renal cell carcinoma 4 cm or less in diameter].

OBJECTIVE: To investigate the optimal margin in nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) 4 cm or less in diameter. METHODS: Eighty-two kidneys with RCC 4 cm or less in diameter resected by radical nephrectomy were prospectively studied. The kidney samples were sectioned at 3 mm interval and examined for multicentricity. On each layer of tissue sectioned, parenchyma margin of 15 mm beyond pseudocapsule was continuously sectioned and examined for completeness of pseudocapsule and extra-pseudocapsule cancer lesion. The farthest distance between extra-pseudocapsule lesion and primary tumor was measured. PCNA expression was detected in 41 patients by using standard SP immunohistochemistry technique. RESULTS: The diameter of 82 primary tumors was 3.4 +/- 0.8 cm (range 1.5 - 4.0 cm). Of these, 31.7% (26/82) were found without intact pseudocapsule and 17.1% (14/82) with positive cancer lesions beyond pseudocapsule. The average distance between extra-pseudocapsule cancer lesion and primary tumor was 0.5 +/- 1.3 mm (range 0 - 5.0 mm), with a confidential interval (CI) of 95% (0.11, 0.94). Statistically, the one side percentile P(95) was 4.9 mm, P(97.5) was 5.0 mm and P(100) was 5.0 mm. The mean PCNA index in the 41 patients with RCC was (29.5 +/- 17.6)%, which was (49.6 +/- 21.5)% in the group with extra-pseudocapsule cancer lesions and (24.6 +/- 12.7)% in the group without (t = 3.162, P = 0.013). The ratio of strong expression was 5/8 in the group with extra-pseudocapsule cancer lesions, and 18.2% (6/33) in the group without the lesions (chi(2) = 6.442, P = 0.011). Logistic regression analysis showed that completeness of pseudocapsule and PCNA index were significant predictors of extra-pseudocapsule cancer lesions (P = 0.019). CONCLUSIONS: These data suggest that when NSS is performed in RCC 4 cm or less in diameter, a margin of more than 5 mm of adjacent parenchyma should be excised with the tumor. Enucleation alone was associated with a significant risk of incomplete excision, and therefore liable for local recurrence. Tumors with incomplete pseudocapsule and(or) high PCNA indices are more likely to have extra-pseudocapsule cancer lesions, so intensive follow-up is necessary after NSS.