Judul: Optimization of Alginate-Chitosan Microcapsules Formation for Leydig Cells Encapsulation
Abstrak: Hypogonadism is a clinical condition characterized by low concentrations of testosterone. It is caused by malfunction of Leydig cells in producing testosterone. Encapsulation method will protect the transplanted cells from the immune system rejection. The aims of this study was to optimize the formation of microcapsules for Leydig cells encapsulation. The microcapsules were made of alginate and chitosan as the first and the second coating agents, respectively. The result showed that the minimum concentration of alginate was 1.5% (w/v) with a viscosity of 33.8 cPs, resulted spherical microcapsules with diameters of 230-270 µm. The optimum concentration of chitosan as the second coating agent was 0.5% (w/v), resulted spherical microcapsule with mechanical stability in 4 hours. Leydig cells can be trapped inside the capsule with a density that proportional with concentration of cells used in the encapsulation.
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Judul: IPB (Bogor Agricultural University)
Abstrak: The use of Percoll gradients for Leydig cells isolation has been reported to influence cell toxicity and reduce the viability and the amount of living cells after culture. To dissolve this problem, study has been carried out used non toxic Nycodenz gradient to isolated and purified the Leydig cells. The use of Nycodenz gradient for the isolation and purification of Leydig cells has not been done by other researchers. To obtain the optimum condition of Leydig cells production, growth factor is required as supporting factors for development of growing cells. Therefore, hCG and ITS has been used in this study. Leydig cells conditioned medium (LCM) contained bioactive materials such as testosterone and growth factors. The Leydig cells conditioned medium as culture medium for bone marrow mesenchymal stem cells will be used to determine its influence to differentiation of cells. The phase of this study included: 1. Isolation and purification of Leydig cells using Nycodenz gradient : (I) with 3 column ( 5 % , 10 % , 15 % ) and ( II ) with 5 columns ( 4 % , 8 % , 10 % , 12 % , 15 % ) and Percoll gradient ( 21 % , 26 % , 34 % , 40 % , 60 % ) as a control . 2. In vitro culture of the best result from cell purification was cultured with the addition of hormones and growth factors : (1) DMEM+NBCS 10% as control, (2) DMEM + NBCS + 2.5 IU/ml hCG , (3) DMEM + NBCS+ 5 ug / ml insulin, 10 ug/ml transferrin, selenium 5 ug/ml (ITS ) and (4) DMEM +NBCS + hCG+ITS . 3 . The concentration of testosteron and protein analyzed from Leydig cells conditioned medium has been used for culturing bone marrow mesenchymal stem cells. The result of first phase study was Nycodenz gradient have the same purity and viability compared with Percoll gradient. After 3 days cultured, in Nycodenz gradient the concentration and viability of Leydig cells more higher than Percoll gradient. The combination of hCG and ITS in DMEM produced Leydig cell proliferation (90.64%) higher compared with hCG (86.99%), ITS (88.35%) and control (86.82%). Proliferation rate (population doubling time, PDT) from primary culture using combination of hCG and ITS showed the fastest (0.88 day) compared with ITS (0.97 day), hCG (1.02 day) and control (1.03 day). The same result of Leydig cells proliferation rate has also showed in first and second cell lines. Testosterone consentration analyzed was the highest (5.25 ng/ml) in DMEM combination with hCG and ITS compared with other treatments (hCG 5.06 ng/ml; ITS 3.19 ng/ml and control 2.46 ng/ml). Differentiation to became Leydig cells from bone marrow mesenchymal stem cells has been known from positive reaction to 3β-HSD staining. Added of hCG to Leydig cells conditioned medium was able to increased the number of Leydig cells to 71.9%. It was also showed that concentration of testosterone has been increased (0.93 ng/ml and 10.22 ng/ml) in the culture medium. The combination of hCG and ITS in DMEM had testosterone (0.71 ng/ml) and protein
Keyword: Leydig cells, rat, Nycodenz, testosterone, mesenchymal stem cells, bone marrow, conditioned medium, transdiferentiation

Judul: Karakteristik Kebakaran Hutan dan Lahan di Taman Nasional Baluran, Kabupaten Situbondo, Jawa Timur
Abstrak: Kejadian kebakaran di Taman Nasional (TN) Baluran pada Mei – November 2018 terjadi pada musim kemarau dan terjadi secara periodik di TN Baluran. Dampak kebakaran berupa perubahan aspek fisik, kimia, dan biologi yang dapat diilustrasikan sebagai keparahan kebakaran. Informasi penting bagi pengelolaan habitat yaitu vegetasi dan suhu udara sebagai aspek biologi dan fisik. Penelitian ini bertujuan untuk mengidentifikasi daerah terbakar dan kelas keparahan kebakaran dan menjelaskan karakteristik kebakaran dari aspek vegetasi dan suhu udara selama periode kebakaran. Karakteristik kebakaran digambarkan dengan analisis normalized burn ratio (NBR) dan normalized difference vegetation index (NDVI) serta perhitungan suhu udara pada kondisi sebelum terbakar, setelah terbakar, dan selisih nilainya. Daerah kebakaran di TN Baluran teridentifikasi seluas 1798.92 ha dan tersebar dalam kelas rendah (1252.71 ha), sedang (543.79 ha), dan parah (2.43 ha). Savana memiliki nilai dNDVI sebesar 0.2543 yang diantaranya disebabkan oleh penebangan kayu akasia untuk kayu bakar dan dNBR 0.0677 yang diindikasikan adanya pembakaran oleh masyarakat untuk pertumbuhan rumput sebagai pakan ternak. Perubahan suhu udara pada savana sebesar 8.6 0C. Perubahan suhu udara semakin meningkat pada setiap kelas keparahan kebakaran yang diekstrak dengan nilai dNBR dibandingkan dNDVI.
Keyword: kebakaran, NBR, NDVI, suhu udara