RESUMEN
To determine effects of Cu, Zn, and Mn source and inclusion during late gestation, multiparous beef cows [nâ =â 48; 649â ±â 80 kg body weight (BW); 5.3â ±â 0.5 body condition score (BCS)] were individually-fed hay and supplement to meet or exceed all nutrient recommendations except Cu, Zn, and Mn. From 91.2â ±â 6.2 d pre-calving to 11.0â ±â 3.2 d post-calving, cows received: no additional Cu, Zn, or Mn (control, CON), sulfate-based Cu, Zn, and Mn (inorganic, ITM) or metal methionine hydroxy analogue chelates (MMHAC) of Cu, Zn, and Mn at 133% recommendations, or a combination of inorganic and chelated Cu, Zn, and Mn (reduce and replace, RR) to meet 100% of recommendations. Data were analyzed with treatment and breeding group (and calf sex if Pâ <â 0.25 for offspring measures) as fixed effects, animal as experimental unit, and sampling time as a repeated effect for serum, plasma, and milk measures over time. Post-calving cow liver Cu was greater (Pâ ≤â 0.07) in MMHAC compared with all other treatments. Calves born to RR had greater (Pâ ≤â 0.05) liver Cu than ITM and CON, and MMHAC had greater (Pâ =â 0.06) liver Cu than CON. Liver Mn was less (Pâ ≤â 0.08) for RR calves than all other treatments. Calf plasma Zn was maintained (Pâ ≥â 0.15) from 0 to 48 h of age in ITM and MMHAC but decreased (Pâ ≤â 0.03) in CON and RR. Gestational cow BW, BCS, and metabolites were not affected (Pâ ≥â 0.13) by treatment, but gestational serum thiobarbituric acid reactive substances (TBARS) were greater (Pâ =â 0.01) for CON than MMHAC. Treatment did not affect (Pâ ≥â 0.13) calf birth size, vigor, placental size and minerals, or transfer of passive immunity. Neonatal calf serum Ca was greater (Pâ ≤â 0.05) for MMHAC than all other treatments; other calf serum chemistry and plasma cortisol were not affected (Pâ ≥â 0.12). Pre-suckling colostrum yield, and lactose concentration and content, were greater (Pâ ≤â 0.06) for MMHAC compared with ITM and RR. Colostral triglyceride and protein concentrations were greater (Pâ ≤â 0.08) for RR than MMHAC and CON. Cow lactational BW and BCS, milk yield and composition, and pre-weaning calf BW and metabolism were not affected (Pâ ≥â 0.13) by treatment. Lactational serum TBARS were greater (Pâ =â 0.04) for RR than CON at day 35 and greater (Pâ ≤â 0.09) for MMHAC at day 60 than all other treatments. Source and inclusion of Cu, Zn, and Mn altered maternal and neonatal calf mineral status, but calf size and vigor at birth, passive transfer, and pre-weaning growth were not affected in this study.
RESUMEN
Since the derivation of the first human embryonic stem cell (hESC) line in 1998, there has been substantial interest in the potential of these cells for regenerative medicine and cell therapy and in the use of hESCs carrying clinically relevant genetic mutations as models for disease research and therapeutic target identification. There is still a need to improve derivation efficiency and further the understanding of the basic biology of these cells and to develop clinical grade culture systems with the aim of producing cell lines suitable for subsequent manipulation for therapy. The derivation of initial hESC lines at King's College London is discussed here, with focus on derivation methodology. Each of the derivations was distinctive. Although the stage and morphology of each blastocyst were generally similar in each attempt, the behaviour of the colonies was unpredictable; colony morphology and development was different with each attempt. Days 5, 6 and 7 blastocysts were used successfully, and the number of days until appearance of stem-like cells varied from 4 to 14 d. Routine characterisation analyses were performed on three lines, all of which displayed appropriate marker expression and survived cryopreservation-thaw cycles. From the lines discussed, four are at various stages of the deposition process with the UKSCB, one is pending submission and two are unsuitable for banking. Continued open and transparent reporting of results and collaborations will maximise the efficiency of derivation and facilitate the development of standardised protocols for the derivation and early culture of hESC lines.
Asunto(s)
Técnicas de Cultivo de Célula/métodos , Células Madre Embrionarias/citología , Universidades , Animales , Diferenciación Celular , Línea Celular , Separación Celular , Embrión de Mamíferos/citología , Congelación , Humanos , Londres , Ratones , Neuronas/citología , Secuencias Repetitivas de Ácidos Nucleicos/genéticaRESUMEN
One response of the UK research community to the public sensitivity and logistical complexity of embryo donation to stem cell research has been the formation of a national network of 'human embryonic stem cell coordinators' (hESCCO). The aim of hESCCO is to contribute to the formation and implementation of national standards for hES cell derivation and banking, in particular the ethical protocols for patient information and informed consent. The hESCCO project is an innovative practical intervention within the broader attempt to establish greater transparency, consistency, efficiency and standardization of hES derivation in the UK. A major outcome of the hESCCO initiative has been the drafting and implementation of a national consent form. The lessons learned in this context may be relevant to other practitioners and regulators as a model of best practice in hES cell derivation.
Asunto(s)
Benchmarking , Células Madre Embrionarias/citología , Modelos Organizacionales , Reino UnidoRESUMEN
The development and implementation of new methods in human embryonic stem cell (hESC) research is fraught with difficulties, not least of which is the highly variable reporting of the number and quality of embryos used to derive hESC lines. Without a clear minimum information convention among the derivation teams, understanding and comparing derivation methods and their potential impact on the resulting stem cell line will continue to be extremely difficult. In order to address this issue, we consulted international teams regarding the implementation of a minimum information convention for derivation with the aim of universal use, data collection and central analysis, followed by a multi-author publication. The responses demonstrated overwhelming support for such a system; over 90% of the respondents agreed that a universal standard for reporting the derivation of hESC lines was essential as part of the international effort to advance the field efficiently, and over 87% plan to use this standard and share collected data in Spring 2008 for central analysis and public dissemination. A number of future steps are planned in order to ensure that this standard evolves with the field and remains relevant and up-to-date. Our aim is to incorporate these data within existing international initiatives aimed at improving derivation standards. This article is an open-access publication in order to make the convention freely available to the international community and encourage universal participation.