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PubMed2005

Root-ABA1, a major constitutive QTL, affects maize root architecture and leaf ABA concentration at different water regimes.

Near-isogenic hybrids (NIHs), developed from crossing maize (Zea mays L.) backcross-derived lines (BDLs) differing for the parental alleles at a major QTL for leaf ABA concentration (L-ABA), were field-tested for 2 years under well-watered and water-stressed conditions. Differences among NIHs for L-ABA and other morpho-physiological traits were not affected by water regimes. On average, the QTL allele for high L-ABA markedly reduced stomatal conductance and root lodging. To elucidate the effects of the QTL on root architecture and L-ABA, root traits of two pairs of BDLs were measured in plants grown in soil columns at three water regimes. Differences among BDLs were not affected by water regimes. Across water regimes, the QTL confirmed its effect on L-ABA and showed a concurrent effect on root angle, branching, number, diameter, and dry weight. Based on these results, it is concluded that the QTL affects root lodging through a constitutive effect on root architecture. In addition, there is speculation that the QTL effects on root traits and L-ABA are probably due to pleiotropy rather than linkage and a model is proposed in which the QTL has a direct effect on root architecture, while indirectly affecting L-ABA.

Abscisic Acid↗
PubMed2026

A genome-wide cross-trait analysis characterizes the shared genetic architecture between rheumatoid arthritis and psychiatric disorders.

OBJECTIVES: Patients with RA have a 2- to 3-fold elevated risk of psychiatric disorders, suggesting an underlying genetic link between these phenotypes. However, the shared genetic architectures and pathological mechanisms driving RA-psychiatric disorder comorbidity remain to be fully elucidated. Herein, we performed cross-trait analysis to investigate the shared genetic architecture between RA and psychiatric disorders. METHODS: Leveraging European-ancestry genome-wide association studies (GWASs) datasets of RA (n = 1 026 690) and 10 major psychiatric disorders (n = 14 307-1 222 882), we performed cross-trait pleiotropic analysis to identify the shared pleiotropic loci and genes between RA and psychiatric disorders, followed by functional annotation and Mendelian randomization analysis to explore the pathological mechanisms underlying RA-psychiatric disorder comorbidity. RESULTS: Our analysis revealed significant positive genetic correlations between RA and seven psychiatric disorders, such as major depressive disorder. From these correlations, we identified 61 pleiotropic loci jointly influencing RA and psychiatric disorder risk, along with 208 pleiotropic genes predominantly involved in immune and inflammatory response biological processes. Druggable target exploration identified 21 drug-gene interactions involving pleiotropic genes, with two genes (RHOA and TRAF3) classified in the clinically actionable category, representing potential therapeutic targets for both RA and psychiatric disorders. Mendelian randomization further demonstrated a bidirectional causal relationship between RA and schizophrenia, while supporting the causal roles of attention-deficit/hyperactivity disorder, major depressive disorder and post-traumatic stress disorder in increasing RA risk. CONCLUSION: Our findings elucidate the shared genetic architecture between RA and psychiatric disorders, providing novel insights into the pathological mechanisms underlying their comorbidity and laying the groundwork for improved comorbidity management.

Arthritis, Rheumatoid↗
PubMed1992

Patterns in aboveground carbon allocation and tree architecture that favor stem growth in young Scots pine from high latitudes.

The production and allocation of aboveground biomass and the characteristics of tree architecture were examined in eight-year-old Scots pine (Pinus sylvestris L.). Considerable among-tree variation existed in tree architecture, total aboveground dry mass production, and dry mass partitioning among tree parts. A linear relationship existed between needle and branch mass. Stem mass was directly proportional to tree height, which in turn was directly proportional to the allocation ratio between stem mass and total needle + branch mass production. The architectural characteristics that were related to a high proportional allocation to stem and high stemwood production were a large mean shoot volume, large mean number of branches per whorl, long needle retention and a high crown length/crown width ratio. Individual trees were found that combined high stemwood production with both high harvest index and high stemwood specific gravity.

Journal Article↗
PubMed2002

Influence of shoot architectural position on shoot growth and branching patterns in Cleyera japonica.

The influence of shoot architectural position on shoot growth and branching patterns was examined in saplings of Cleyera japonica Thunb. (Theaceae), an understory, broad-leaf evergreen woody species. Shoot length varied with branching order and the vertical position of the branch in the crown. In the upper crown, shoot length decreased with increasing branching order, whereas in the lower crown, differences in shoot length among branching orders were not significant. These results demonstrate that it is important to consider not only individual shoots, but also the relationships between shoots in terms of their architectural positions when studying the development of crown architecture in trees. Shoot branching patterns also varied with branching order and the vertical position of the branch in the crown. In the upper crown, branching was mainly sylleptic. In the middle of the crown, mainly proleptic branches were produced. In the lower crown, there was little branching. The importance of these trends in shoot growth and shoot branching patterns in terms of carbon production efficiency is discussed.

Japan↗
PubMed2002

Reduced photosynthesis in old oak (Quercus robur): the impact of crown and hydraulic architecture.

We tested the hypothesis that changes in crown architecture of old pedunculate oak trees (Quercus robur L. ssp. robur Kl. et Kr. et Rol.) reduce leaf specific hydraulic conductance of shoots, thereby limiting stomatal conductance and assimilation of affected shoots. At the end of summer 1999, hydraulic conductance and leaf specific hydraulic conductance, measured with a high-pressure flow meter in 0.5- to 1.5-m long shoots, were 27 and 39% lower, respectively, in shoots of low vigor compared with vigorously growing shoots in a 165-year- old stand in southeastern Germany. Two types of bottlenecks to water transport can be identified in shoots of old oak trees, namely nodes and abscission zones. The reduction in hydraulic conductance was especially severe in shoots with diameters of less than 2 mm. Maximum stomatal conductance and maximum net assimilation rate increased significantly with hydraulic conductance and leaf specific hydraulic conductance. Our data support the hypothesis that changes in shoot and consequently crown architecture observed in aging trees can limit photosynthesis by reducing shoot hydraulic conductance. Thus, in addition to increasing pathway length and lower conductivity of xylem in old trees, structural changes in shoot and crown architecture need to be considered when analyzing water relations and photosynthesis in mature and declining trees.

Photosynthesis↗
PubMed2004

Constraints on light interception efficiency due to shoot architecture in broad-leaved Nothofagus species.

Shoot architecture may significantly alter mean quantum flux on foliage and thus, photosynthetic productivity. There is currently only limited information about plastic alterations in shoot structure caused by within-canopy variation in mean integrated irradiance (Q(int)) in broad-leaved trees. We studied leaf and shoot structure, and nitrogen and carbon content in late-successional, widely distributed, temperate, broad-leaved Nothofagus taxa to determine the architectural controls on light harvesting and photosynthetic performance. Nothofagus fusca (Hook. f.) Oersted has larger leaves and less densely leaved shoots than the N. solandri varieties. Nothofagus solandri var. solandri (Hook. f.) Oersted is characterized by rounder leaves that potentially have a larger overlap than the ovate-triangular leaves of N. solandri var. cliffortioides (Hook. f.) Poole. Leaf dry mass (M(A)) and nitrogen content (N(A)) per unit area increased with increasing Q(int) in all species, demonstrating enhanced investment of photosynthetic biomass in high light. Although M(A) differed between species at a common irradiance, there was a uniform relationship between N(A) and Q(int) across species. Leaf carbon content per dry mass and leaf dry mass to fresh mass ratio also scaled positively with irradiance, suggesting greater structural investments in high light. In all species, shoots became more horizontal and flatter at lower Q(int), implying an enhanced use efficiency of direct irradiance in natural leaf positions. In contrast, irradiance effects on leaf aggregation varied among species. Across the data, leaf overlap or leaf area density was often greater at lower irradiances, possibly as a result of limited carbon availability for shoot axis extension growth. In N. fusca, leaves of which were more aggregated in high light, the shoot silhouette to total leaf area ratio (S(S)) declined strongly with increasing irradiance, demonstrating a lower light harvesting efficiency at high Q(int). This effect was only moderate in N. solandri var. cliffortioides and S(S) was independent of Q(int) in N. solandri var. solandri. Although the efficiency of light interception at high irradiances was lowest in N. fusca, this species had the greatest nitrogen content per unit shoot silhouette area (2N(A)/S(S)), indicating superior shoot-level photosynthetic potential. These data collectively demonstrate that shoot architecture significantly affects light interception and photosynthesis in broad-leaved trees, and that structural carbon limitations may constrain leaf light harvesting efficiency at low irradiance.

Magnoliopsida↗
PubMed2006

A finite element model for investigating effects of aerial architecture on tree oscillations.

A finite element model was developed to study the influence of aerial architecture on the structural dynamics of trees. The model combines a complete description of the axes of the aerial architecture of the plant with numerical techniques suitable for dynamic nonlinear analyses. Trees were modeled on the basis of morphological measurements that were previously made on three 4-year-old Pinus pinaster Ait. saplings originating from even-aged stands. Calculated and measured oscillations were compared to evaluate model behavior. The computations allowed the characteristics of the fundamental mode of vibration to be estimated with satisfactory accuracy. Inclusion of a topological description of the aerial system in a mechanical model provided insight into the effect of tree architecture on tree dynamic behavior. Simplifications of the branching pattern in the model led to overestimations of the natural swaying frequency of saplings by 10 to 20%. Inadequate values of stem and root anchorage stiffness resulted in errors of 10 to 20%. Modeling results indicated that aerodynamic drag of needles is responsible for 80% of the damping in the studied trees. Additionally, damping of stem movement is reduced by one half when branch oscillations are not considered. It appears that the efficiency of the dissipative mechanisms depends directly on crown topology.

Biomechanical Phenomena↗
PubMed2007

Hydraulic architecture and photosynthetic capacity as constraints on release from suppression in Douglas-fir and western hemlock.

We compared hydraulic architecture, photosynthesis and growth in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade-intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade-tolerant species, to study the temporal pattern of release from suppressive shade. In particular, we sought to determine whether hydraulic architecture or photosynthetic capacity is most important in constraining release. The study was conducted at two sites with mixed stands of 10- to 20-year-old Douglas-fir and western hemlock. At one site, the stand had been thinned allowing release of the understory trees, whereas at the other site, the stand remained unthinned. Douglas-fir had lower height growth (from 1998-2003) and lower relative height growth (height growth from 1998 to 2003/height in 1998) than western hemlock. However, relative height growth of released versus suppressed trees was higher in Douglas-fir (130%) than in western hemlock (65%), indicating that, although absolute height growth was less, Douglas-fir did release from suppression. Release seemed to be constrained initially by a limited photosynthetic capacity in both species. Five years after release, Douglas-fir trees had 14 times the leaf area and 1.5 times the leaf nitrogen concentration (N (area)) of suppressed trees. Needles of released western hemlock trees had about twice the maximum assimilation rate (A (max)) at ambient [CO(2)] as needles of suppressed trees and exhibited no photoinhibition at the highest irradiances. After release, trees increased in leaf area, leaf N concentration and overall photosynthetic capacity. Subsequently, hydraulic architecture appeared to constrain release in Douglas-fir and, to a lesser extent, in western hemlock. Released trees had significantly less negative foliar delta(13)C values than suppressed trees and showed a positive relationship between leaf area:sapwood area ratio (A (L)/A (S)) and delta(13)C, suggesting that trees with more leaf area for a given sapwood area experienced a stomatal limitation on carbon gain. Nonetheless, these changes had no significant effects on leaf specific conductivities of suppressed versus released trees of either species, but leaf specific root conductance was significantly lower in released Douglas-fir.

Photosynthesis↗
PubMed1990

Crown architecture of Populus clones as determined by branch orientation and branch characteristics.

Crown architecture, including branching pattern, branch characteristics and orientation of proleptic and sylleptic branches was studied in five poplar clones (Populus deltoides, P. trichocarpa and P. trichocarpa x P. deltoides hybrids), grown under intensive culture in the Pacific Northwest, USA. Branch characteristics measured were number, length, diameter, biomass and the angles of origin and termination. The results suggest that genotype has a major influence on crown architecture in Populus. Clonal differences in branch characteristics and branching patterns were found that resulted in striking differences in crown form and architecture. Branch angle and curvature differed significantly among clones, and among height growth increments within clones. Branch length and diameter were significantly correlated in all clones. Sylleptic branches and the considerable leaf area they carry have important implications for whole tree light interception, and thus, play a critical role in the superior growth and productivity of certain hybrid poplar clones. The considerable variation in branch characteristics implies a strong justification for including them in selection and breeding programs for Populus.

Journal Article↗
PubMed1999

Implications for interrelationships between nuclear architecture and control of gene expression under microgravity conditions.

Components of nuclear architecture are functionally interrelated with control of gene expression. There is growing appreciation that multiple levels of nuclear organization integrate the regulatory cues that support activation and suppression of genes as well as the processing of gene transcripts. The linear representation of genes and promoter elements provide the potential for responsiveness to physiological regulatory signals. Parameters of chromatin structure and nucleosome organization support synergism between activities at independent regulatory sequences and render promoter elements accessible or refractory to transcription factors. Association of genes, transcription factors, and the machinery for transcript processing with the nuclear matrix facilitates fidelity of gene expression within the three-dimensional context of nuclear architecture. Mechanisms must be defined that couple nuclear morphology with enzymatic parameters of gene expression. The recent characterization of factors that mediate chromatin remodeling and identification of intranuclear targeting signals that direct transcription factors to subnuclear domains where gene expression occurs link genetic and structural components of transcriptional control. Nuclear reorganization and aberrant intranuclear trafficking of transcription factors for developmental and tissue-specific control occurs in tumor cells and in neurological disorders. Compromises in nuclear structure-function interrelationships can occur as a consequence of microgravity-mediated perturbations in cellular architecture.

Cell Nucleus↗
PubMed1997

Evaluation of classic architectural criteria in non-mycosis fungoides cutaneous lymphomas.

Ninety-seven cases of non-mycosis fungoides (non-MF) cutaneous lymphoma were evaluated employing published criteria for the categorization of B- and T-cell cutaneous malignancies. Included in the study were 77 primary and secondary cutaneous B-cell lymphomas, in which the diagnosis was supported by immunohistochemical studies identifying lineage. These cases were randomized with 20 cases of non-MF and T-cell lymphoma. Hematoxylin and eosin (H & E)-stained slides from each case were reviewed by at least two dermatopathologists, who were unaware of the previous diagnoses, and a judgment regarding histologic pattern was rendered. The histologic criteria employed emphasized architectural features. For B-cell patterns, these included the presence of dense perivascular, periappendageal and/or nodular collections of lymphocytes, centering in the deep dermis, and separation from the epidermis by a grenz zone. Employed criteria for cutaneous T-cell pattern included location restricted primarily to the upper dermis, interstitial pattern, the presence of epidermotropism, and the lack of a grenz zone. Three B-cell lymphomas were judged to have indeterminate patterns. Four of 74 (5.4%) of the remaining B-cell lymphomas were incorrectly categorized as T-cell lymphomas by architectural criteria. The most striking findings included epidermotropism in rare B-cell lymphomas. Three of the four miscategorized cases were large-cell lymphomas. A preference for B-cell pattern was also confirmed in non-MF T-cell lymphomas. We conclude that most B-cell lymphomas in the skin demonstrate a recognizable B-cell pattern, but rarely a pattern more reminiscent of T-cell lymphoma may be seen. This may occur more often with B-large-cell lymphomas. In addition, this study supports previous work indicating that many non-MF T-cell lymphomas show prominent architectural features typically ascribed to B-cell lymphomas. In summary, our findings support the impression that the vast majority of non-MF lymphomas show a B-cell pattern regardless of their lineage. As such, caution is indicated with regard to pattern interpretation.

Adult↗
PubMed1999

Avoiding the great train wreck: standardizing the architecture for online curricula.

The advent of the World Wide Web and related technologies has encouraged medical schools to generate a wealth of online curricular materials. Unfortunately, the diversity and abundance of user-friendly authoring tools have enabled individual instructors within and among medical schools to proliferate educational resources with often widely dissimilar architectures. Because there are no universal standards for educational technology, the resulting information islands cannot be easily managed, reused, or shared with other educators and institutions. Thoughtful planning and reuse of online educational materials could allow instructors to present subject matter more consistently across the curriculum, discover new teaching resources, easily create new materials, reduce unnecessary duplication, and better integrate the basic and clinical sciences. To make this possible, standardized, object-oriented architecture is needed. While several excellent HTML authoring tools and integrated courseware packages are available, differences in their technologies and methods impede inter-operability between the various products and the materials they create. Through the National Learning Infrastructure Initiative, the Instructional Management Systems (IMS) specification has emerged as a global standard for online teaching and learning environments. This proposed standard defines a common architecture for content management and delivery.

Computer Systems↗
PubMed1988

Measure-set computed tomographic analysis of internal architectures of lumbar disc. Clinical and histologic studies.

Measure-set computed tomography (MSCT) scan was performed in 30 adult subjects (17 men and 13 women, mean age 42 years) and eight cadavers (five men and three women, mean age 42 years) to establish prospectively a normal CT pattern of the internal architectures of the lumbar disc. Based on the uniformity or nonuniformity of MSCT composition of the nucleus pulposus (NP) and annulus fibrosus (AF), and also on how well NP was discerned from the surrounding AF, the internal architecture could be categorized into well-defined (WD), intermediate (IM), and ill-defined (ID) types. An age and prevalence study of the categorized disc showed that, with age, the disc undergoes an architectural transformation from WD through IM to ID. In addition, 72.5% of WD-type discs and 72.1% of ID-type discs occurred in the third and fourth decades and in the sixth and seventh decades, respectively, suggesting that the former is a young form with mild degeneration and the latter an old form with advanced degeneration. Fifty-eight percent of WD-type discs and 60.4% of ID-type discs occurred at L1-3 and L4-S1 levels, respectively, regardless of age. This finding suggests the old form tends to occur at the lumbosacral junction, which is the site of maximum weight bearing in humans. The correlation of water content and histologic findings of degeneration with the three categorized disc types in cadavers showed that WD, IM, and ID discs were associated with the largest, intermediary, and least amount of water of NP, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1997

Retinal vascular network architecture in low-birth-weight men.

BACKGROUND: Low birth weight is associated with hypertension and increased cardiovascular mortality, but the mechanism of this association is not known. Hypertension is accompanied by abnormalities of the microvasculature including rarefaction. OBJECTIVE: To test the hypothesis that low birth weight is associated with an alteration in microvascular architecture. DESIGN: A stratified random sample of 100 men aged 64-74 years was selected from a cohort of men whose birth weights were known. They were of relatively high or low birth weight ('high' > or = 3700 g, 'low' < or = 3200 g) and high or low systolic blood pressure (high > or = 160 mmHg, low < or = 140 mmHg). METHODS: Retinal arteriolar geometry was defined in terms of arteriolar bifurcation angles and junction exponents (a measure of the relative diameters of parent and daughter vessels), measured from photographic diapositives using operator-directed image analysis. RESULTS: Members of low-birth-weight groups had significantly narrower bifurcation angles than did members of high-birth-weight groups (74 +/- 1 degree versus 78 +/- 1 degree, P= 0.017 by analysis of variance). There was no significant difference between angles in members of groups with high and low blood pressures. Neither birth weight nor blood pressure grouping affected junction exponents. CONCLUSIONS: Narrower bifurcation angles are associated with increased circulatory energy costs and may be related to a lower than normal microvascular density. Our finding of differences in retinal microvascular architecture might reflect a persistent alteration in vascular architecture as a result of an impairment of foetal development and could provide a mechanistic link between low birth weight and subsequently increased cardiovascular risk.

Aged↗
PubMed1995

Cortical architectural abnormalities and MIB1 immunoreactivity in gangliogliomas: a study of 60 patients with intracranial tumors.

Gangliogliomas are generally low grade neoplasms composed of mixtures of neoplastic glial and neuronal elements whose origin and exact nature are still controversial. We studied a series of 60 intracranial gangliogliomas looking for coexistent cortical architectural abnormalities (cortical dysplasia, microdysgenesis) and to determine if tumor behavior correlates with MIB1 (marker of cellular proliferation) labeling. The patients included 34 males and 26 females who ranged in age from 6 months to 55 years (mean 20 years). Thirty-eight tumors (63%) were located in the temporal lobe and 6 (10%) in the frontal lobe. Fifty-four patients (90%) presented with seizures (most with intractable epilepsy) and the duration of seizures ranged from 1 to 38 years (mean 14 years). In all cases, the predominant glioma component resembled a low grade fibrillary astrocytoma. In 14 tumors (23%), an oligodendroglial component was present. In one case, the glial component resembled an anaplastic astrocytoma. The tumors were characterized variously by perivascular chronic inflammation (N = 45, 75%), vascular proliferation (N = 36, 60%), granular bodies (N = 54, 90%), binucleated neurons (N = 36, 60%), calcification (N = 28, 47%), and cystic degeneration (N = 26, 43%). Meningeal involvement by tumor was observed in five (8%) cases. In 38 patients, sufficient tissue was resected to evaluate for the presence of concomitant cortical architectural abnormalities. Cortical architectural abnormalities were identified near to but clearly separate from the tumor in 19 (50%) patients. Only four patients including the anaplastic tumor died with tumor progression. MIB1 indices (positive tumor cells/1,000 tumor cells counted) in 54 cases ranged from 0 to 10.2 (mean 1.1 +/- 1.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

Architectural characteristics of muscle in black and white college football players.

PURPOSE: The purpose of this study was to determine whether architectural characteristics of skeletal muscle differ by race. METHODS: Skeletal muscle architectural characteristics and body composition were studied in 13 black and 31 white male college football players. Fat-free mass (FFM) and percentage body fat (% fat) were determined by hydrostatic weighing technique. Muscle thickness (MTH) was measured by B-mode ultrasound at 13 anatomical sites. Isolated MTH and muscle pennation angle (PANG) of the triceps long head, vastus lateralis, and gastrocnemius medialis muscles were measured by ultrasound, and fascicle length was estimated. RESULTS: There were no significant differences between blacks and whites in isolated MTH, PANG, and fascicle length in the triceps long head, vastus lateralis, and gastrocnemius medialis muscles. On average, % fat and FFM of black and white football players were 18.8 +/- 4.6% and 17.2 +/- 5.6% for % fat, and 89.9 +/- 15.6 kg and 89.1 +/- 10.4 kg for FFM, respectively. Blacks had a significantly greater, 30%-quadriceps (P < 0.05), 50%-hamstrings (P < 0.05), biceps (P < 0.01), and abdomen (P < 0.01) MTH than those of whites. Standing height and body weight were similar between blacks and whites, but the ratio of leg length to standing height was significantly greater in blacks compared with whites. CONCLUSIONS: It appears that although there may be race differences in anatomical stature, muscle architecture is likely independent of race.

Adult↗
PubMed2005

Morphology, architecture, and biomechanics of human cervical multifidus.

STUDY DESIGN: Cadaveric dissections and biomechanical modeling were used to study the human cervical multifidus muscle. OBJECTIVES: To describe attachment patterns of the multifidus in the cervical region, to quantify the muscle's architecture, and to use a biomechanical model to calculate the moment-generating capacity of the cervical multifidus. SUMMARY OF BACKGROUND DATA: Deep neck muscles such as the multifidus may play an important role in cervical spine stability and neck pain. However, there are limited data regarding the fascicular attachments or architecture parameters necessary to calculate force and moment. METHODS: The multifidus spinae was studied by dissection of nine cadaveric specimens. Fascicles were grouped according to attachment, and architecture parameters (musculotendon length, fascicle length, and physiologic cross-sectional area) were quantified. The data were used in a biomechanical model to calculate moment arm, force-, and moment-generating capacity of the multifidus. RESULTS: The multifidus originates from the facet capsules of lower cervical vertebrae and the transverse processes of upper thoracic vertebrae. The fascicles span 2 to 5 vertebral segments from origin to insertion, and they insert on the spinous processes and laminae of superior cervical vertebrae. For each fascicular subgroup, musculotendon lengths ranged from 2.0 to 6.9 cm, fascicle lengths ranged from 1.2 to 3.7 cm, and physiologic cross-sectional area ranged from 0.1 to 1.0 cm2. The total moment-generating capacity of the cervical multifidus in the neutral posture was predicted to be approximately 0.7 Nm for extension and lateral bending and 0.3 Nm for axial rotation. CONCLUSIONS: The fascicular attachment pattern of the multifidus spinae in the cervical region appears to be unique to that region. The direct attachment to cervical facet capsules supports a possible role in neck pain and injury. Characterizing the biomechanical function of the multifidus is important for the analysis of normal and pathologic conditions.

Adult↗
PubMed2003

Tissue-engineered large intestine resembles native colon with appropriate in vitro physiology and architecture.

OBJECTIVE: Novel production and in vitro characterization of tissue engineered colon. SUMMARY BACKGROUND DATA: The colon provides important functions of short chain fatty acid production, sodium and water absorption, and storage. We report the first instance of tissue-engineered colon (TEC) production from autologous cells and its in vitro characterization. METHODS: Organoid units, mesenchymal cell cores surrounded by a polarized epithelia derived from full thickness sigmoid colon dissection from neonatal Lewis rats, adult rats, and tissue engineered colon itself, were implanted on a polymer scaffold into the omentum of syngeneic hosts. TEC was either anastomosed at 4 weeks or excised for Ussing chamber studies or histology, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay. RESULTS: TEC was generated by 100% of all animals without regard to tissue source, the first instance of engineered intestine from adult cells or an engineered tissue. TEC architecture is identical to native with muscularis propria staining for actin, acetylcholinesterase detected in a linear distribution in the lamina propria, S100-positive cells, ganglion cells, and a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick end labeling assay similar to native colon. Ussing chamber data indicated in vitro function consistent with mature colonocytes, and a positive short circuit current response to theophylline indicating intact ion transfer. TEM showed normal microarchitecture. Colon architecture was maintained in anastomosis with gross visualization of fluid uptake. CONCLUSIONS: TEC can be successfully produced with fidelity to native architecture and in vitro function from neonatal syngeneic tissue, adult tissue, and TEC itself.

Animals↗