Strands Of Tissue Research Articles

Unusual Case of Prominent Chiari Network Trapped in the Left Atrium

We describe a case of an unusually prominent Chiari network in a premature neonate who was evaluated with echocardiography. The network, which is an embryologic remnant, was extensive, mobile, and moved in and out of the right ventricle. Later, tissue strands passed the foramen ovale and ultimately became trapped in the left atrium. The differential diagnosis included thrombus, tumor, vegetation, and ruptured chordae. (J Am Soc Echocardiogr 1998;11:71-3.)

Age-related electrophysiological and histological changes in rabbit hearts: Age-related changes in electrophysiology

Because of the known higher incidence of cardiac arrhythmia in aged patients we tried to define the underlying arrhythmogenic substrate by quantifying those electrophysiological alterations in aged rabbit hearts, which are commonly believed to be arrhythmogenic, relating them to histological findings in the same hearts. This is the first investigation that analyses the effect of ageing on the epicardial excitation spreading. Isolated hearts from young (ten weeks) and old (1.5–2 years) white New Zealand rabbits were perfused according to the Langendorff-technique, submitted to epicardial potential mapping for 60 min and investigated histologically. Electrophysiological data in aged hearts showed a) a higher variability of the activation pattern, b) an increased dispersion of the epicardial potential duration; c) a prolongation of the AV-conduction time and of the duration of the epicardial activation signal, which was fractionated in aged hearts. Histological findings showed extensive incorporation of fat cells and connective tissue in ventricular and AV-node tissues, which may explain the prolonged conduction time, and a marked hypertrophy of the ventricular myocytes. The observed high dispersion, the broadened and fractionated epicardial activation signal and the enhanced variability of the activation patterns may be due to the observed long strands of collageneous tissue separating ventricular muscle fibres in aged hearts. These changes help to explain the enhanced susceptibility to arrhythmogenic stimuli with age.

Renal Cell Carcinoma: Diagnosis Based on Metastatic Manifestations

Renal Cell Carcinoma: Diagnosis Based on Metastatic Manifestations

The Long Saphenous Vein Compartment

Objective: To define the relationship between the long saphenous vein and the connective framework of the subcutaneous tissue (hypodermis) of the lower limb. Methods: The connective skeleton of the hypodermis was studied by anatomical dissection, stereomicroscopy of cross-sectioned specimens and ultrasound imaging in 88 lower extremities. Results: The long saphenous vein runs for most of its length in a narrow compartment delineated deeply by the muscular fascia and superficially by a connective tissue lamina descending from the inguinal ligament in the anteromedial part of the thigh and medial aspect of the calf. These two fascia fuse at the boundaries of the compartment. The long saphenous vein adventitia is anchored to both fasciase by thick connective tissue strands. Conclusion: The anatomical relationship between the long saphenous vein and the connective framework of the hypodermis suggests that: (1) only the vein running within the deep compartment of the hypodermis should be considered as the ‘true’ long saphenous vein; (2) the other subcutaneous veins running outside the compartment should be considered as collaterals of the long saphenous vein; (3) the connective sheath surrounding the long saphenous vein could oppose dilatation of this vessel should valvular incompetence develop; and (4) thigh muscle contraction could modify the calibre of the long saphenous vein as happens in the deep veins. Finally, the authors propose to term the deep compartment of the medial thigh and the leg hypodermis the ‘long saphenous vein compartment’ and consequently the hypodermic connective lamina, by which it is superficially delimited, as the ‘long saphenous vein fascia’.

Proton density and apoplastic domains within soybean nodules in relation to the oxygen diffusion barrier

ABSTRACTA spin‐echo pulse sequence was used to obtain 1H nuclear magnetic resonance microimages of soybean nodules, with resolution to 40 mm and 3D presentation. At an acquisition time (TR) of c. 270 ms and a short echo time (TE) of 8.3 ms, a high proton intensity was detected in infected tissue and vascular strands, relative to the cortex. A longer TE of 15.5 ms was associated with a relatively low proton intensity in infected tissue. Thus protons in infected tissue were characterized by a short T2. Following detopping of the plant, or treatment of the root system with Ar:O2, proton intensity (TE 5.9, TR 120 ms) decreased exponentially in a zone corresponding to the inner cortex‐outer infected region. This result is interpreted as being caused by a loss of water mobility (i.e. increase in viscosity) or a filling of intercellular air spaces with fluid (i.e. loss of air‐water interfaces). The membrane impermeant tracer lucifer yellow was observed to infiltrate from the rhizosphere through the nodule cortex into the infected region in intact nodules of detopped and Ar:O2‐treated, but not control, plants. This result is consistent with the filling of air spaces with fluid following the imposed treatments, allowing infiltration of aqueous tracers. Variation in intercellular air space volume within the inner cortex has been suggested as a mechanism to allow a variable rate of diffusion of O2 into soybean nodules.

Maxillary Growth following Atelocollagen Implantation on Mucoperiosteal Denudation of the Palatal Process in Young Rabbits: Implications for Clinical Cleft Palate Repair

The implantation of atelocollagen matrix on the denuded surface of palatal bone following cleft palate repair has been used because it enhances wound healing. This study was performed to determine whether the beneficial effect of atelocollagen matrix implantation on the prevention of scar tissue contraction also inhibits the scar's interference with the growth of maxillary bone.Fifty New Zealand White rabbits (aged 4 weeks) underwent palatal mucoperiosteal denudation, and etelocollagen matrix was implanted on the left palatal process. The opposite side was left open as a control.Histopathologically, the implantation side exhibited early infiltration of mononuclear cells and fibroblasts, and better growth of connective tissue strands and epithelium. In addition, the formation of rate ridges were seen that were similar to the normal mucosa. The bone of the atelocollagen-implanted side was covered with regenerated periosteum-like layers, but that of the control side was lined by granulation tissue, suggesting the existence of continuous inflammation on the periosteal region. When the animals reached adulthood (aged 24 weeks), the areas of scars and palatal processes, palatal shelf width, molar teeth incline, and bone mineral contents were measured and compared between sides. The atelocollagen-applied scars showed less contraction, the area and width of atelocollagen-implanted palatal processes showed more satisfactory growth, and the dental arch deformity was suppressed in comparison with the control side.Our results suggest that the use of atelocollagen matrix on the denuded bone surface following cleft palate repair decreases the scar's effect on maxillary growth.

A new type of “bioartificial” nerve graft for bridging extended defects in nerves

In the rat sciatic nerve, a gap of around 10 mm in nerve continuity seems to be the maximal distance which can be successfully repaired by silicone tubes. In this study we tested if a new artificial nerve graft, composed of eight polyamide filaments (diameter 250 microns) placed inside silicone tubes (1.8 mm inner diameter), could be used to bridge an extended gap (15 mm) in rat sciatic nerve. Silicone tubes containing eight polyamide sutures were found to support regeneration across such a gap. After 4 weeks sensory fibres had bridged the gap and grown into the distal nerve segment as revealed by a positive pinch reflex test as well as positive staining for neurofilaments in the distal nerve segment. Myelinated axons could be observed in the tissue matrix formed in between and peripheral to the synthetic filaments along the whole length of the tube. In contrast, when silicone tubes without filaments were used to bridge the 15 mm gap, the tubes contained only fluid or in two cases a thin tissue strand. No positive pinch reflex response was elicited in the nerve segment distal to such a tube. We conclude that the new artificial nerve graft can be used to support regeneration across extended gaps in nerves.

Pithiness and Growth of Radish Tubers as Affected by Irradiance and Plant Density

Pithiness in radish tubers (Raphanus sativusL.) is a syndrome where xylem parenchyma cells die and are filled with air. Features associated with rapid tuber growth such as large cells, great distances between strands of vascular tissue and rupture of xylem vessels have been suggested to induce pithiness. The objective of this study was to analyse the extent to which pithiness in radish was related to tuber growth. Growth rates were varied by altering irradiance and plant density. In addition, the relationship between pithiness and tuber growth (length, diameter, fresh mass) was investigated in batches of plants grown under identical conditions. The growth rates of shoot and tuber strongly increased with increasing inter-plant distance and irradiance. Our results suggest a ‘true’ effect of assimilate supply on dry matter partitioning, as not only the ratio between shoot and root dry mass, but also the slope of this relationship decreased with increasing irradiance and inter-plant distance. Within a treatment the ratio between tuber growth and shoot growth remained constant with plant age. Increase in length of the tuber did not appear to be an important factor in inducing pithiness. Within a batch of plants, a positive correlation between tuber diameter and pithiness was observed only for tubers smaller than 14 mm. An increase in both irradiance and inter-plant distance increased tuber size (diameter, mass) and pithiness, but the effects on pithiness could not be ascribed only to different tuber sizes. Pithiness strongly increased with plant age and it was concluded that pithiness occurred, to a great extent, according to genetic programming. The data showed that for treatments which affect tuber growth, conclusions about their effects on pithiness depend on whether comparisons were made at the same tuber size or the same time, explaining apparent contradictions in the literature.

In vitro germination and seedling development of Dalzellia zeylanica (Gardner) Wight (Podostemaceae)

Seeds were germinated aseptically on thermocole cubes in 1/5 strength Murashige and Skoog's (1962) liquid medium (MS). The mature embryo has two well-developed cotyledons but lacks a plumule and a distinct radicle. The embryo emerges from the seed by the elongation of cotyledons and hypocotyl. The epidermal cells at the radicular pole elongate to form rhizoids. Proliferation of cells of the plumular pole gives rise to six to eight leaf primordia. An endogenously formed protuberance in the hypocotyledonary region develops into a green, dorsiventral thallus. The margins of the thallus also bear leaves. The presence of a band of small meristematic cells (five or six layers thick) below the apical mantle of large irregular cells has been seen in paradermal sections of thallus tips. Presumably they participate in the growth of the thallus. A vertical section of the thallus shows parenchymatous ground tissue and a strand of vascular tissue in the middle of the thallus which divides to supply the branches of the thallus. Tracheary elements have spiral/annular thickenings. Sieve elements showed callose when stained with aniline blue and viewed under a fluorescence microscope.

Fine needle aspiration cytology (FNAC) of paragangliomas of head and neck

Eight cases of paragangliomas of head and neck were diagnosed by fine needle aspiration cytology from January, 1984 till January, 1992. The age of the patients ranged from 18 years to 38 years. The patients presented with painless slowly growing cervical masses. Routine investigations did not give any clue to the diagnosis. The diagnostic cytologic features were loose clusters of cells separated by bands of connective tissue strands. The large cells have pleomorphic nuclei with abundant pale, eosinophilic, finely reticular cytoplasm. The histopathological findings correlated with the cytological findings. Extreme paucity of Indian literature in FNAC of paragangliomas prompted to publish this article.

Morphology, histochemistry, and differentiation of the cat's epiglottic cartilage: a supporting organ composed of elastic cartilage, fibrous cartilage, myxoid tissue, and fat tissue.

In carnivores, the supporting organ of the epiglottis is usually called "epiglottic cartilage" (EC) although it is composed of elastic cartilage and unilocular fat storing cells. We studied the cat's EC in order to decide whether these fat storing cells are true adipocytes or fat storing (dedifferentiated) chondrocytes. ECs were studied in cat embryos at gestation days 40 and 60, in newborn, postnatal, and adult cats. We used classical staining methods, immunohistochemistry, and transmission electron microscopy to identify the different kinds of tissues contributing to the EC and to follow their differentiation. The cat's EC was defined by a layer of coarse collagen fibers representing a tunica albuginea. This tunica covered irregularly formed and irregularly sized areas of elastic cartilage, fibrous cartilage, myxoid tissue, and lobules of unilocular fat cells. All these tissue showed regular morphology. Adipocytes were provided with continuous basal laminae and fat lobules were well supplied with capillaries. Alcianophilia of ground substance was observed in all tissue components but was strongest in elastic cartilage. Most islets of elastic cartilage adhered to the tunica albuginea of the EC at one surface and were connected to the opposite surface by coarse strands of connective tissue traversing the organ. Intercalated areas of fibrous cartilage contained fuchsinophilic collagen bundles. Myxoid tissue was characterized by stellate cells in alcianophilic ground substance with intermingled fuchsinophilic bundles. All kinds of supporting tissues combined with each other without clear demarcation. Immunohistochemistry revealed strong reactivity for S-100 of chondrocytes, myxoid cells, and fat cells. Chondrocytes and myxoid cells also stained for glial fibrillary acidic protein, neurofilament protein 200, and neuron specific enolase. During development, condensation of mesenchymal cells indicated the blastema of the EC at gestation day 40. At day 60, delicate collagen fibrils indicated the future tunica albuginea, faint alcianophilia was noted in the ground substance, and multilocular fat cells were scattered throughout the blastema. At birth, alcianophilia was moderate and multilocular fat cells were numerous. Three weeks after birth, single and grouped unilocular fat cells were seen, alcianophilia of ground substance was prominent, and former blastema cells presented as ramified myxoid cells. Eight weeks after birth, the EC primarily consisted of myxoid tissue, but the first islets of cartilage were seen in the center of myxoid areas. Unilocular fat cells already formed lobules. These results show that in the cat EC a) differentiation of adipocytes precedes differentiation of all the other tissue components, and b) differentiation of myxoid tissue precedes differentiation of cartilage. It is concluded that myxoid tissue may serve as a precursor of fibrous and elastic cartilage.

Tonsillar lipoma: a case report

Benign tumours of the tonsils are rare. Only a few cases of tonsillar lipoma have been previously reported. The case of a pedunculated polypoid lipoma of the palatine tonsil in a 44-year-old Japanese woman is presented. The 'polyp' was excised and an histopathological examination was carried out. The 'polyp' contained dilated lymphatics in the dense fibrous connective tissue beneath the overlying mucosal epithelium and below the mature fat tissue with intervening strands of fibrous tissue.

Agonadal presumptive XX/XY leukochimeric pig.

XX/XY chimeric pigs are uncommon and their reproductive anatomy is variable and unpredictable. A piglet was identified by its enlarged vulva as a possible intersex. Venous blood was collected at 1.5 and 9 months for karyotyping and determination of testosterone and estrone sulphate concentrations. At 1 year euthanasia was performed. The reproductive tract was carefully dissected and examined histologically. As the animal matured the vulva did not develop relative to the size of the animal. Lymphocyte cultures indicated a 70% XX/30% XY chimera. The reproductive tract consisted of a strand of tissue enveloped by fascia. Histological study revealed presumptive Wolffian derivatives, coiled bilateral ducts along the tract, and a Müllerian derivative, a medially located duct in the caudal third of the tract. No gonads were found. Plasma levels of estrone sulfate and testosterone were negligible. In utero exposure to exogenous androgens from a male co-twin or weak endogenous adrenal androgens may account for the enlarged vulva at birth and retention of the androgen dependent Wolffian duct primordia. An atesticular state is supported by retention of the Müllerian duct primordia and the negligible peripheral sex steroids.

Implantation of Fetal Tissue for the Management of Parkinson's Disease

A relatively simple method for implanting fetal tissue within the human basal ganglia is described. Stereotactic techniques are used to deposit 14 to 16 strands of fetal mesencephalic tissue in a linear array within the putamen bilaterally. To eliminate the need for targeting each needle pass independently, we have devised a novel rotating template/micromanipulator apparatus that can be mounted on a Cosman-Roberts-Wells stereotactic frame. The template contains two parallel columns of nine holes, all spaced at 4-mm intervals. It can be aligned to the longitudinal axis of the putamen and targeted with coordinates for the center point of the putamen. Surgery is performed on an awake patient. Short-term morbidity (4-6 wk) in the form of variability of Parkinsonian signs, particularly "off" symptoms and mild confusion, appears to be the rule with simultaneous bilateral implants.

Structural characterization of muscles and epithelial sheaths of the oviduct of Stomoxys calcitrans (Diptera: Muscidae).

Fine structure of both muscle and epithelial cells in the oviduct of Stomoxys calcitrans (L.) was characterized. Each tubular section of the oviduct consisted of an inner epithelial sheath enveloped by an outer network of muscle fibers that showed noticeable variation in cross-sectional thickness. Some regions consisted of a single cellular layer, whereas others were composed of two or more layers of cells. Moreover, a wide variation in muscle fiber orientation was observed, with some cells appearing circular and others appearing nearly longitudinal. The myofibrils of oviduct muscles were separated into sarcomeres of irregular alignment. The classical A (1 microns in length) and I bands of myofilaments were evident, but the Z disk consisted of discontinuous rows of dense bodies. In partially contracted muscle cells, some myofilaments of the A band passed between the dense bodies of the Z band. T-system tubules were evident and formed dyads with sarcoplasmic reticulum. The structural integrity of the oviduct was maintained by connective tissue strands between muscles and the epithelial sheath. Many of these strands consisted of basal lamina. Epithelial cells that line the inner sheath of the oviduct were cuboidal. In transection, these cells revealed a prominent apical microvillar region with large numbers of mitochondria and an extensive infolding of the basal plasma membrane.

Black stem galls on aspen: anatomy and histochemistry

Large black stem galls occur sporadically on trembling aspen (Populus tremuloides) in western Canada. Although little is known about their cause or structure, trees having these galls are less likely than surrounding aspen to have advanced decay caused by the fungus Phellinus tremulae. The anatomy and histochemistry of black galls and associated branch galls were studied and compared with normal wood and bark. Light microscopy showed that the cambium of black galls produces greater numbers of cells per growth ring and that growth rings are two to three times wider than normal. Vessel elements and fibers are unusually small and misshapen. Gall xylem has characteristics associated with wounding or infection: ray cells filled with phenolic deposits, and vessel elements occluded by tyloses and granular material. Frequent radial strands of undifferentiated callus tissue surrounded by necrophylactic periderms indicate sites of cambial damage of unknown cause. White areas within dark-colored gall xylem of some samples were free of most of these abnormalities, suggesting that a persistent agent is required for continuing tumor growth. Thickened outer bark harbored a variety of saprophytic fungi, especially hyphomycetes. Surface and internal morphology of black galls was also compared with similar stem galls caused by poplar budgall mites (Aceria parapopuli) and was found to be different. Bacteria, fungi, or mites were not obvious within living tissue, and further studies are necessary to determine the etiology of black galls. Key words: Populus tremuloides, poplar, black gall, wood anatomy.

Autoradiographic and biochemical evidence for the systemic translocation of systemin in tomato plants

The movement of systemin, the 18-amino-acid polypeptide inducer of proteinase inhibitors in tomato (Lycopersicon esculentum L.) plants, was investigated in young tomato plants following the application of [14C]systemin to wounds on the surface of leaves. Wholeleaf autoradiographic analyses revealed that [14C]systemin was distributed throughout the wounded leaf within 30 min, and then during the next several hours was transported to the petiole, to the main stem, and to the upper leaves. The movement of [14C]systemin was similar to the movement of [14C]sucrose when applied to leaf wounds, except that sucrose was slightly more mobile than systemin. Analyses of the radioactivity in the petiole phloem exudates at intervals over a 5-h period following the application of [14C]systemin to a wound demonstrated that intact [14C]systemin was present in the phloem over the entire time, indicating that the polypeptide was either stable for long periods in the phloem or was being continually loaded into the phloem from the source leaf. The translocation pathway of systemin was also investigated at the cellular level, using light microscopy and autoradiography. Within 15 min after application of [3H]systemin to a wound on a terminal leaflet, it was found distributed throughout the wounded leaf and was primarily concentrated in the xylem and phloem tissues within the leaf veins. After 30 min, the radioactivity was found mainly associated with vascular strands of phloem tissue in the petiole and, at 90 min, label was found in the phloem of the main stem. Altogether, these and previous results support a role for systemin as a systemic wound signal in tomato plants.

Multiterminal proprioceptors in Squilla mantis (Stomatopoda, Crustacea).

A series of morphologically simple multiterminal proprioceptors is described in the thoracopods of the hoplocaridian crustacean, Squilla mantis, which is a primitive offshoot of the main malacostracan evolutionary line. The description given here is primarily for the largest and most complex receptor that occurs in the second thoracopod, the raptorial limb. These stretch receptors, which lie distally in the coxopodite, consist of single multiterminal sensory neurons with widely branching dendrites innervating broad connective tissue strands. The single primary dendrite divides dichotomously or, occasionally, trichotomously to produce a large number of terminal dendrites. The terminal dendrites, which exhibit a beaded structure, run parallel to the connective tissue strands' longitudinal axis. Dendrites possess an elaborate connective tissue sheath consisting of a single inner glial layer and a multiple outer connective tissue layer. The presence of the beaded structure has been confirmed by transmission electron microscopy (EM), and, because microtubule density does not vary with dendrite diameter, the beads are not fixation artifacts. Beads have high numbers of mitochondria and glycogen deposits, which suggests that they have a high metabolic activity. Dendritic tips are not associated with beads, arise from the terminals of smaller dendrites, and are embedded in the extracellular ground matrix of the connective tissue strand, where they lie parallel to and surround bundles of elastic fibrils. The different degree of development within the receptor series allows comparison between functionally different limbs, and comparison is made with other segmental receptor series. The evolution of multiterminal proprioceptors is discussed.

Anatomy of the valve of the coronary sinus (thebesian valve)

AbstractThe valve of the coronary sinus was studied in 50 hearts from dissection room cadavers. It varied from a flap that covered up to 70% of the ostium of the coronary sinus, to a few small strands of tissue. In 3 cases no valve was present. In most cases (35 out of 50), the valve covered <50% of the ostium of the coronary sinus, so it is unlikely to play an important role in preventing reflux into the coronary sinus. Microscopically, the valve was found to contain layers of myocardium, most of which disappeared in the less well formed valves, but some myocardium was persistent even in the most rudimentary valves studied. © 1994 Wiley‐Liss, Inc.

The anatomic basis of the anterior vaginal flap used for neourethra construction in female-to-male transsexuals.

For lengthening of the urethra in female-to-male transsexuals, an anterior vaginal wall flap is used. This flap is separated from the posterior urethral wall down to the attachment at the urethral meatus following a glistening cleavage plane. In this paper we present the anatomic and histologic basis of this flap. Prior to this, the relevant vaginal anatomy will be discussed. The anterior vaginal wall and posterior urethral wall are not indissectible structures; this is true even in the caudal two-thirds of the urethra. A long and narrow flap can be raised, thanks to the abundant vascular supply of the vaginal wall and the musculomucosal quality of the flap. A previously performed anatomic and histologic survey of the anterior vaginal wall has shown that the glistening cleavage plane is not composed solely of fascia, but rather consists of longitudinal strands of muscle, fibrous tissue, and elastin.