Genetic instability during embryogenic cloning of celery

Genetically marked tissues of celery (Apium graveolens) were employed to contrast genetic and chromosomal stability in serially bulk-transferred callus and regenerated plants. After six months in culture, 84% of the callus cells were karologically indistinguishable from normal, while the remainder exhibited chromosome loss and/or fusion. All of 50 clones derived from this tissue expressed the control phenotype with respect to heterozygous isozyme markers. Of 95 plants regenerated from the same tissue, 94 were phenotypically indistinguishable from the original explant donor, and cytogenetic analyses revealed the presence in 4.3% of an accessory chromosome, while the remainder were normal diploids. Analysis of the selfed progeny of these regenerated plants revealed the presence of a new recessive mutation causing abnormal leaf morphology at a frequency of 1.8%. Only one of 40 cells in 12-month-old callus tissue was karyologically indistinguishable from normal, the remainder consisting primarily of hypodiploids. The observation that all 50 clones were phenotypically heterozygous was statistically inconsistent with the hypothesis that hypodiploidy was associated with random complete chromosome loss. The culture had, at this point, lost the ability to regenerate. It is speculated that embryogenic cloning of celery may be suitable under certain circumstances for direct field establishment, but that levels of new genetic variation are sufficiently high to preclude its use for seed production.     

Chemically-defined medium for growth and differentiation of mixed epithelial and connective tissues in organ culture

The effect on tissue differentiation and growth in vitro of certain of the factors implicated in collagen synthesis (ascorbic acid, α-ketoglutarate and oxygen) and the influence of hydrocortisone was studied using organ cultures of fetal mouse mandible as a mixed epithelial and connective tissue system. Using serum-free Waymouth’s MB 752/1 chemically-defined medium, addition of high levels of ascorbic acid (300 μg per ml), hydrocortisone (1 μg per ml) and oxygen (95%) enhanced differentiation in a number of tissues, in particular skin and appendages, tooth germs and bone, while osteoid and dentine production were noticeably promoted. It is suggested that an essential aspect of media design for organ culture involves the incorporation of collagen-promoting factors to the in vitro environment particularly with regard to the controlling role implicated for collagen in a variety of biological processes. Some of the work reported here was undertaken while A. H. Melcher was a member of the Department of Dental Science, Royal College of Surgeons of England, London, England.     

Inverse investigation of non-Fourier heat conduction in tissue

This paper attempts to describe the heat conduction in tissue using the dual-phase-lag mode. Evaluating the thermo-physical parameters is one of the ways to certify the thermal behavior. As a result, the paper simultaneously and inversely estimates the values of τ_q, τ_T and α for bologna based on the dual-phase-lag mode with the measurement data in the literature. The inconsistence in theory discovered in the literatures is eliminated. The calculated results of temperature variation with the estimated values of τ_q, τ_T and α at the measurement location are very close to the experimental data and address the rationality of the present results.     

Nonthermal electromagnetic fields: From first messenger to therapeutic applications

Nonthermal pulsed electromagnetic fields, from low frequency to pulse-modulated radio frequency, have been successfully employed as adjunctive therapy for the treatment of delayed and non-union fractures, fresh fractures and chronic wounds. Recent increased understanding of the mechanism of action of electromagnetic fields (EMF) has permitted technologic advances allowing the development of EMF devices which are portable and disposable, can be incorporated into dressings, supports and casts, and can be used over clothing. This broadens the use of non-pharmacological, non-invasive EMF therapy to the treatment of postoperative pain and edema to enhance surgical recovery. EMF therapy is rapidly becoming a standard part of surgical care, and new, more significant, clinical applications for osteoarthritis, brain and cardiac ischemia and traumatic brain injury are in the pipeline. This study reviews recent evidence which suggests that calmodulin (CaM)-dependent nitric oxide signaling is involved in cell and tissue response to weak nonthermal EMF signals. There is abundant evidence that EMF signals can be configured a priori to increase the rate of CaM activation, which, in turn, can modulate the biochemical cascades living cells and tissues employ in response to external insult. Successful applications in pilot clinical trials, coupled with evidence at the cellular and animal levels, provide support that EMF is a first messenger that can modulate the response of challenged biological systems.     

Estimation of the physiological mechanical conditioning in vascular tissue engineering by a predictive fluid-structure interaction approach

The in vitro replication of physiological mechanical conditioning through bioreactors plays a crucial role in the development of functional Small-Caliber Tissue-Engineered Blood Vessels. An in silico scaffold-specific model under pulsatile perfusion provided by a bioreactor was implemented using a fluid-structure interaction (FSI) approach for viscoelastic tubular scaffolds (e.g. decellularized swine arteries, DSA). Results of working pressures, circumferential deformations, and wall shear stress on DSA fell within the desired physiological range and indicated the ability of this model to correctly predict the mechanical conditioning acting on the cells-scaffold system. Consequently, the FSI model allowed us to a priori define the stimulation pattern, driving in vitro physiological maturation of scaffolds, especially with viscoelastic properties.     

In Vitro Cultivation of Borrelia duttonii on Cultures of SflEp Cells

Borrelia duttonii strain 406 K, a causative agent of relapsing fever, could not be cultivated in vitro in currently available media for borreliae. We have developed an in vitro cultivation system by using SflEp cell cultures. The average increases of the number of borreliae, when inoculated with 1.0 × 10⁵ organisms per ml from infected mice, were 23-fold and 150-fold in the primary culture and the 3rd subculture, respectively. Even a single borrelia could propagate in this cultivation system. This system will be useful for immunological and physiological studies on uncultivable Borrelia strains.     

The first insight into the trace element status of human adrenal gland accompanied by elemental alterations in adrenal adenomas

BackgroundThe baseline status of trace metals in adrenal tissue is unresolved, while the elemental profile for any adrenal pathology has not been examined so far. This study aimed to determine the baseline status of important toxic (Ni, As, Cd, Pb, Th, U) and essential trace elements (Mn, Co, Cu, Zn, Se) in healthy adrenal tissues (HATs) as well as to examine whether there are alterations in the elemental composition of adenomatous adrenal tissues (AATs). Furthermore, this study aimed to find potential trace metals that could play a role in the pathogenesis of adrenal adenoma (AA).MethodsThe study included 45 patients diagnosed with AA. Impacts of relevant parameters such as gender, age, smoking habits and nodular sizes were considered. All samples were subjected to microwave digestion and the trace elements were determined by inductively coupled plasma mass spectrometry (ICP-MS).ResultsThis is the first study that provided an insight into the elemental status of HATs. It was also shown that AATs had altered trace metal contents. Compared to HATs, the most significant findings were related to the high content of essential (Cu, Mn, Se, Zn) and Pb as a non-essential metal. Although gender, age and smoking habits had a modest effect on metal profiles, the most significant alterations were related to the nodular diameter above 4 cm, indicating that the growth of benign tumor could influence changes in elemental composition.ConclusionFor the first time the baseline contents of essential and toxic trace metals in HATs were determined. The results of this study may highlight the role of toxic and essential trace metals in AAs and could provide new insights into the molecular basis of pathophysiological changes caused by the hazardous effects of trace metals on adrenal structure and function.     

马尾松胚乳愈伤组织发生的初步研究

为获取马尾松(Pinus massoniana)单倍体材料，建立其胚乳组织培养体系，对马尾松胚乳不同的消毒方法进行筛选，并分析不同基本培养基、生长调节剂配比和热激处理对愈伤诱导的影响。结果表明，胚乳的最佳消毒方式为75%酒精处理30 s+2% NaClO消毒15 min，外植体污染率为0，死亡率仅为15.56%；生长素可促进愈伤诱导且是必需的；细胞分裂素浸泡种子可代替培养基中的细胞分裂素，并能取得比较好的胚乳愈伤诱导效果，1.0 mg·mL-1 6-BA浸泡30 min处理的效果最佳，在培养基WPM+NAA 2.0 mg·L-1+2,4-D 1.0 mg·L-1+蔗糖30 g·L-1+琼脂7 g·L-1中，愈伤诱导率高达87.78%；培养基DCR+NAA 2.0 mg·L-1+6-BA 1.0 mg·L-1+蔗糖30 g·L-1+琼脂7 g·L-1的胚乳愈伤诱导率最高(68.75%)；热激处理可提高胚乳愈伤的诱导率和质量，以相对湿度85%下45 ℃热激10 min最佳，总愈伤诱导率为66.25%，成团愈伤诱导率达8.75%；增殖培养以培养基WPM+NAA 0.1 mg·L-1+6-BA 2.0 mg·L-1+蔗糖30 g·L-1+琼脂7 g·L-1最佳，增殖率达83.33%。     

Propagation of soft tissue artifacts to the center of rotation: A model for the correction of functional calibration techniques

This paper presents a mathematical model for the propagation of errors in body segment kinematics to the location of the center of rotation. Three functional calibration techniques, usually employed for the gleno-humeral joint, are studied: the methods based on the pivot of the instantaneous helical axis (PIHA) or the finite helical axis (PFHA), and the “symmetrical center of rotation estimation” (SCoRE). A procedure for correcting the effect of soft tissue artifacts is also proposed, based on the equations of those techniques and a model of the artifact, like the one that can be obtained by double calibration. An experiment with a mechanical analog was performed to validate the procedure and compare the performance of each technique. The raw error (between 57 and 68 mm) was reduced by a proportion of between 1:6 and less than 1:15, depending on the artifact model and the mathematical method. The best corrections were obtained by the SCoRE method. Some recommendations about the experimental setup for functional calibration techniques and the choice of a mathematical method are derived from theoretical considerations about the formulas and the results of the experiment.     

In vitro fertilization and seed development inTrifolium

Summary Pistils ofTrifolium repens L. andT. ambiguum Bieb. were cultured on an agar-based modified Murashige-Skoog medium. Pistils with and without accessory floral parts were removed from flowers of selected clones ofT. repens, hand-pollinated under aseptic conditions, and planted on the medium. Pistils cultured without accessory floral parts showed no evidence of fertilization after 2 weeks. However, 52% of thoseT. repens pistils cultured with calyx lobes and pedicels contained ovules with maturing embryos 12 days after in vitro cross-pollination. Pistils fromT. ambiguum intraspecific cross-pollinations could not be cultured successfully under the same conditions; however, addition of various combinations of auxin, cytokinin, and gibberellic acid enhanced embryo growth. Fertilization and partial embryo development occurred in interspecific crosses betweenT. ambiguum andT. repens orT. hybridum only whenT. ambiguum was used as the pistillate parent. These results indicate that embryological development under in vitro conditions closely parallels in situ development although growth regulator requirements may vary among species. This work is Technical Contribution 1785 from the South Carolina Agricultural Experiment Station and was supported by SCAES-USDA Cooperative State Research Agreement No. 616-15-65.