Teknik Pemuliaan Kentang dan Produksi Bibit Kentang Bebas Virus di Texas, USA

Kentang merupakan sumber karbohidrat penting di negara maju seperti Amerika Serikat, Eropa dan Australia. Produktivitas kentang di Amerika Serikat mencapai 40 ton/ha. Berbagai varietas kentang juga tersedia dengan kegunaan yang berbeda seperti untuk keripik, kentang goreng (french fries), kentang rebus dan kentang panggang. Tulisan ini bertujuan untuk memaparkan teknik pemuliaan kentang untuk mendapatkan berbagai varietas serta metode perbanyakan benih kentang bebas virus melalui teknik kultur jaringan di Texas. Kunci utama keberhasilan pemuliaan kentang di Texas adalah ketersediaan sumber daya genetik kentang yang luas, serta evaluasi di lapang (field day) untuk genotipe-genotipe potential hasil pemuliaan yang melibatkan para peneliti, petani, pelaku pasar dan media. Teknik kultur jaringan digunakan untuk perbanyakan benih terpilih, serta meminimalisasi penyebaran penyakit yang berasal dari umbi seperti virus kentang PVX, PVY dan PLRV. Penggunaan teknik kultur jaringan juga mampu menekan biaya produksi benih karena mengurangi penggunaan ruang untuk stok benih dan perbanyakan di rumah kaca. Tahapan pemuliaan, produksi benih di lapang, evaluasi varietas, introduksi benih in vitro, perbanyakan in vitro, teknik eliminasi virus dan produksi benih di rumah kaca dideskripsikan pada tulisan ini

Optimasi Metode Cryotherapy Untuk Mengeliminasi Virus Pada Tunas Kentang in Vitro

Penggunaan benih kentang generasi awal dan bebas virus merupakan kunci keberhasilan produksi kentang berkualitas. Cryotherapy (perendaman dalam nitrogen cair) merupakan teknik terbaru untuk mengeliminasi virus pada benih kentang. Salah satu kendala dalam penerapan teknologi cryotherapy ialah tingkat daya hidup eksplan yang masih rendah. Penelitian ini bertujuan untuk mengetahui efektifitas teknik enkapsulasi-dehidrasi untuk mendapatkan tunas yang sehat setelah perendaman dalam nitrogen cair. Ujung tunas in vitro ukuran 2–3 mm dari empat genotipe kentang di prakultur selama 3 hari secara bertahap pada media MS dengan penambahan gula 0,25 M, 0,5 M, dan 0, 75 M. Kemudian tunas dienkapsulasi, didehidrasi selama 5 jam, lalu direndam dalam nitrogen cair selama 60 menit lalu dihangatkan kembali dalam waterbath selama 3 menit. Tunas dalam kapsul kemudian dikulturkan pada media MS +30 g/l sukrosa + 8 g/l agar + 0,4 mg/l BAP + 1 mg/l GA3 untuk pemulihan, lalu dipelihara di ruang kultur dengan suhu 24oC. Daya hidup ujung tunas diamati pada minggu ke-8 dengan menggunakan kriteria skoring sebagai berikut: (1) pemutihan jaringan dan tidak ada respons pertumbuhan, (2) kalus mencokelat, (3) kalus hijau, (4) tumbuh tunas, dan (5) planlet sehat. Hasil penelitian menunjukkan daya hidup ujung tunas bervariasi antargenotipe. Skor daya hidup berkisar 1–2 (frekuensi 2–10) pada perlakuan nitrogen cair, yang menunjukkan tidak ada respons pertumbuhan tunas, beberapa memperlihatkan pertumbuhan kalus. Tunas pada perlakuan kontrol (tanpa perendaman dalam nitrogen cair) menunjukkan skor daya hidup 5 (frekuensi 1–7), di mana ujung tunas mampu beregenerasi menjadi planlet

Optimasi Metode Cryotherapy untuk Mengeliminasi Virus pada Tunas Kentang In Vitro (Optimation of Cryotherapy Method to Eliminate Virus on In Vitro Potato Shoot Tips)

Penggunaan benih kentang generasi awal dan bebas virus merupakan kunci keberhasilan produksi kentang berkualitas. Cryotherapy (perendaman dalam nitrogen cair) merupakan teknik terbaru untuk mengeliminasi virus pada benih kentang. Salah satu kendala dalam penerapan teknologi cryotherapy ialah tingkat daya hidup eksplan yang masih rendah. Penelitian ini bertujuan untuk mengetahui efektifitas teknik enkapsulasi-dehidrasi untuk mendapatkan tunas yang sehat setelah perendaman dalam nitrogen cair. Ujung tunas in vitro ukuran 2–3 mm dari empat genotipe kentang di prakultur selama 3 hari secara bertahap pada media MS dengan penambahan gula 0,25 M, 0,5 M, dan 0, 75 M. Kemudian tunas dienkapsulasi, didehidrasi selama 5 jam, lalu direndam dalam nitrogen cair selama 60 menit lalu dihangatkan kembali dalam waterbath selama 3 menit. Tunas dalam kapsul kemudian dikulturkan pada media MS +30 g/l sukrosa + 8 g/l agar + 0,4 mg/l BAP + 1 mg/l GA3 untuk pemulihan, lalu dipelihara di ruang kultur dengan suhu 24oC. Daya hidup ujung tunas diamati pada minggu ke-8 dengan menggunakan kriteria skoring sebagai berikut: (1) pemutihan jaringan dan tidak ada respons pertumbuhan, (2) kalus mencokelat, (3) kalus hijau, (4) tumbuh tunas, dan (5) planlet sehat. Hasil penelitian menunjukkan daya hidup ujung tunas bervariasi antargenotipe. Skor daya hidup berkisar 1–2 (frekuensi 2–10) pada perlakuan nitrogen cair, yang menunjukkan tidak ada respons pertumbuhan tunas, beberapa memperlihatkan pertumbuhan kalus. Tunas pada perlakuan kontrol (tanpa perendaman dalam nitrogen cair) menunjukkan skor daya hidup 5 (frekuensi 1–7), di mana ujung tunas mampu beregenerasi menjadi planlet.KeywordsCryopreservation; Solanum tuberosum; Kultur jaringan tanaman; Eliminasi virusAbstractVirus-free, early generation seed is a key in the production of high quality potatoes. Cryotherapy (exposure to liquid nitrogen) is a new and promising method of virus elimination. One bottleneck in cryotheraphy method is survival of the explants after treatment with liquid nitrogen. This study investigated the effectiveness of enkapsulasi-dehidrasi method to obtain survival explants. Shoot tips were precultured for 3 days in MS media with sucrose addition of 0.25 M, 0.5 M and 0.75 M. Shoot tips were then encapsulate, dehydrate for 5 hours, expose to liquid nitrogen for 60 minutes and rewarm in waterbath for 3 minutes. Beads with shoot tips were then cultured in MS media + 30 g/l sucrose + 8 g/l agar + 0.4 mg/l BAP + 1 mg/l GA3 for recovery, and placed in 24oC culture room. Shoot tip survival was assessed at 8 weeks using the following scoring criteria: (1) tissue bleaching and no growth response, (2) brown callus, (3) green callus, (4) shoot growth, and (5) plantlet establishment. Survival was varied among genotypes. Survival scored between 1–2 (frequency 2–10) on liquid nitrogen treatment, showing shoot tips are mostly has no growth response, only some callus growth. Shoot tips on control treatment (without exposure in liquid nitrogen) shows survival scored 5 (frequency 1–7), i.e. shoot tips able to regenerate into plantlets

Protein dimerization generates bistability in positive feedback loops

Bistability plays an important role in cellular memory and cell fate determination. A positive feedback loop can generate bistability if it contains ultrasensitive molecular reactions. It is often difficult to detect bistability based on such molecular mechanisms due to its intricate interaction with cellular growth. We constructed transcriptional feedback loops in yeast. To eliminate growth alterations, we reduced the protein levels of the transcription factors by tuning the translation rates over two orders of magnitude with designed RNA stem-loops. We modulated two ultrasensitive reactions, homodimerization and the cooperative binding of the transcription factor to the promoter. Either of them is sufficient to generate bistability on its own and when acting together, a particularly robust bistability emerges. This bistability persists even in the presence of a negative feedback loop. Since protein homodimerization is ubiquitous, it is likely to play a major role in the behavior of regulatory networks

A core outcome set for pre-eclampsia research:an international consensus development study

Objective: To develop a core outcome set for pre-eclampsia. Design: Consensus development study. Setting: International. Population: Two hundred and eight-one healthcare professionals, 41 researchers and 110 patients, representing 56 countries, participated. Methods: Modified Delphi method and Modified Nominal Group Technique. Results: A long-list of 116 potential core outcomes was developed by combining the outcomes reported in 79 pre-eclampsia trials with those derived from thematic analysis of 30 in-depth interviews of women with lived experience of pre-eclampsia. Forty-seven consensus outcomes were identified from the Delphi process following which 14 maternal and eight offspring core outcomes were agreed at the consensus development meeting. Maternal core outcomes: death, eclampsia, stroke, cortical blindness, retinal detachment, pulmonary oedema, acute kidney injury, liver haematoma or rupture, abruption, postpartum haemorrhage, raised liver enzymes, low platelets, admission to intensive care required, and intubation and ventilation. Offspring core outcomes: stillbirth, gestational age at delivery, birthweight, small-for-gestational-age, neonatal mortality, seizures, admission to neonatal unit required and respiratory support. Conclusions: The core outcome set for pre-eclampsia should underpin future randomised trials and systematic reviews. Such implementation should ensure that future research holds the necessary reach and relevance to inform clinical practice, enhance women's care and improve the outcomes of pregnant women and their babies. Tweetable abstract: 281 healthcare professionals, 41 researchers and 110 women have developed #preeclampsia core outcomes @HOPEoutcomes @jamesmnduffy. [Correction added on 29 June 2020, after first online publication: the order has been corrected.].</p

Pediatric Hospitalizations Associated with 2009 Pandemic Influenza A (H1N1) in Argentina

Fil: Libster, Romina. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Bugna, Jimena. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Coviello, Silvina. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Hijano, Diego R. Hospital De Niños Sor María Ludovica, La Plata; Argentina.Fil: Dunaiewsky, Mariana. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Reynoso, Natalia. Hospital Municipal Materno Infantil de San Isidro; Argentina.Fil: Cavalieri, Maria L. Hospital Eva Perón, Benito Juárez, Buenos Aires; ArgentinaFil: Guglielmo, Maria C. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Areso, M. Soledad. Hospital Eva Perón, Benito Juárez, Buenos Aires; ArgentinaFil: Gilligan, Tomas. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Santucho, Fernanda. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Cabral, Graciela. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Gregorio, Gabriela L. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Moreno, Rina. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Lutz, Maria I. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Panigasi, Alicia L. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Saligari, Liliana. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Caballero, Mauricio T. Hospital De Niños Sor María Ludovica, La Plata; Argentina.Fil: Egües Almeida, Rodrigo M. Hospital De Niños Sor María Ludovica, La Plata; Argentina.Fil: Gutierrez Meyer, Maria E. Hospital De Niños Sor María Ludovica, La Plata; Argentina.Fil: Neder, Maria D. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Davenport, Maria C. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Del Valle, Maria P. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Santidrian, Valeria S. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Mosca, Guillermina. Ministerio de Ciencia, Técnica e Innovación. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Alvarez, Liliana. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Landa, Patricia. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Pota, Ana. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Boloñati, Norma. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Dalamon, Ricardo. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Sanchez Mercol, Victoria I. Hospital Eva Perón, Benito Juárez, Buenos Aires; Argentina.Fil: Espinoza, Marco. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Peuchot, Juan Carlos. Hospital Eva Perón, Benito Juárez, Buenos Aires; Argentina.Fil: Karolinski, Ariel. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Bruno, Miriam. Hospital General de Agudos Carlos G. Durand, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Borsa, Ana. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Ferrero, Fernando. Hospital General de Niños Pedro de Elizalde, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Bonina, Angel. Hospital De Niños Sor María Ludovica, La Plata; Argentina.Fil: Ramonet, Margarita. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Albano, Lidia C. Hospital Nacional Profesor Alejandro Posadas, El Palomar, Buenos Aires; Argentina.Fil: Luedicke, Nora. Ministerio de Ciencia, Técnica e Innovación. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Alterman, Elias. Fundación Infant, Ciudad Autónoma de Buenos Aires; Argentina.Fil: Savy, Vilma L. ANLIS Dr.C.G.Malbrán. Instituto de Enfermedades Infecciosas; Argentina.Fil: Baumeister, Elsa. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Virología. Servicio de Virosis Respiratoria; Argentina.Fil: Chappell, James D. Vanderbilt University. Pathology, Nashville, Tennessee; Estados Unidos.Fil: Edwards, Kathryn M. Vanderbilt University. Departments of Pediatrics, Nashville, Tennessee; Estados Unidos.Fil: Melendi, Guillermina A. Vanderbilt University. Departments of Pediatrics, Nashville, Tennessee; Estados Unidos.Fil: Polack, Fernando P. Vanderbilt University. Departments of Pediatrics, Nashville, Tennessee; Estados Unidos.Background: While the Northern Hemisphere experiences the effects of the 2009 pandemic influenza A (H1N1) virus, data from the recent influenza season in the Southern Hemisphere can provide important information on the burden of disease in children. Methods: We conducted a retrospective case series involving children with acute infection of the lower respiratory tract or fever in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase-chain-reaction assay and who were admitted to one of six pediatric hospitals serving a catchment area of 1.2 million children. We compared rates of admission and death with those among age-matched children who had been infected with seasonal influenza strains in previous years. Results: Between May and July 2009, a total of 251 children were hospitalized with 2009 H1N1 influenza. Rates of hospitalization were double those for seasonal influenza in 2008. Of the children who were hospitalized, 47 (19%) were admitted to an intensive care unit, 42 (17%) required mechanical ventilation, and 13 (5%) died. The overall rate of death was 1.1 per 100,000 children, as compared with 0.1 per 100,000 children for seasonal influenza in 2007. (No pediatric deaths associated with seasonal influenza were reported in 2008.) Most deaths were caused by refractory hypoxemia in infants under 1 year of age (death rate, 7.6 per 100,000). Conclusions: Pandemic 2009 H1N1 influenza was associated with pediatric death rates that were 10 times the rates for seasonal influenza in previous years