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At least 667 records · Page 37Linked to original sources
PubMed2000

Morphogenesis in short-term and long-term anther derived calli of Oenothera hookeri de vries.

Anther culture of O. hookeri on Murashige and Skoog (1962) medium supplemented with 2 mg l-1 2,4-dichlorophenoxyacetic acid and 2 mg-1 1-naphthaleneacetic acid produced callus formation. When subcultured onto medium lacking auxin, the callus regenerated through the organogenic pathway. Non-organogenic and organogenic callus was observed using histological methods after 2, 3 and 24 weeks in culture. Three types of calli were recognized: non-organogenic friable calli, organogenic friable calli with roots and organogenic hard calli with shoots. The microscopical sections showed striking differences in tissue organization among friable and compact calli. Vascular bundles were prominent in compact calli, but were not found in friable calli. Calli sections showed at light microscopy cells at two developmental stages; differentiated highly vacuolated cells and meristematic small isodiametric cells with densely stained cytoplasm. At electron microscopy level abnormal chloroplasts were present in non-organogenic calli, while chloroplasts were well developed in organogenic hard calli. Peroxisomes with paracrystalline protein bodies were abundant in both types of calli.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2000

[Postischemic reorganization of dendritic architectonics of the hippocampal CA3 region in albino rats predisposed to seizures].

Total short term ischemia of brain was induced experimentally in albino rats (10 min long clamp of heart vascular bundle). Using Golgi Silver nitrate impregnation geometry of pyramidal neurons dendritic tree was studied in sector of hippocampus in norm, postischemic period (d 1.30 and 90) healthy animals and those predisposed to cramps. Significant reduction of dendrite volume, total length, dendrite territory, parameters of dendrite arborization were shown on the background of stable numerical density of neurons in all animals who survived brain ischemia. The extent of reduction, volume and duration of changes of parameters of dendritic tree geometry was higher in animals predisposed to cramps than in high threshold animals without cramps. Possible mechanisms of postischemic neuron "epileptization" were discussed.

Acoustic Stimulation↗
PubMed2000

[Leaf anatomy study in Solanaceae of Venezuela. V. leaf anatomy of eleven species of Cestrum L] .

Leaf anatomy of the following eleven species: C. buxifolium Kunth, C. humboldtii Francey, C. lindenii Dunal, C. mariquitense Kunth, C. megalophyllum Dunal, C. olivaceum Francey, C. pariense Steyerm., C petiolare Kunth, C. scandans Vahl, C. strigilatum Ruiz et Pavón and C. tomentosum L.f. is described. Transverse sectioning, bruise and clearing according to the classical methods for optical microscopy were made. The species studied show dissimilitude in relation to a) fohar blade: thickness and sinuosity of epidermal cell walls; type, density and presence of trichornes, leaf type according the position of the stomata, thickness of both palisade and spongy parenchy-ma, number of spongy parenchyma layers, occurrence or not of paranchymatous sheath and sclerifled cells in mesophyll, tmbeculae or projection walls b) Midvein: degree of development and arrangement of the parenchyma and collenchyma, c) Petiole: size and form in transverse section, presence of ornamented cuticle, peridermis and degree of development of the sclerenctiyma next to vascular bundles.

Plant Leaves↗
PubMed2000

Magnetic resonance imaging (MRI) of Saccharum officinarum L. (sugarcane) during its growth for sucrose content.

Magnetic Resonance Imaging (MRI) was employed to monitor changes in image intensities in stems of sugarcane which reflect on the increase in sucrose concentration. Contrast in images originates in the increase of sucrose concentration in the aqueous phase of the predominant parenchyma cells and physiological changes. In matured stems mixed MR intensity patterns were observed in transverse planes. We associate this due to the reflection of vascular bundles in ground parenchyma cells which constitute 80% sucrose storage.

Magnetic Resonance Imaging↗
PubMedDate not supplied

An active intervention on flap vasculature: flap prefabrication by pedicle implantation, delay, pre-expansion, pre-grafting, tissue engineering, biomaterials and perforators surgery.

The technology of flap prefabrications is a new, powerful tool in plastic and reconstructive surgery. It is based on an old idea, while applying the latest innovations in surgery. It involves any modification of a surgical flap done before its transfer to the final donor site, including surgical delay, pre-expansion, pre-grafting, the use of tissue engineering, biomaterials and perforators surgery, or the creation of a new pedicle by staged transfer of a vascular bundle. The different possibilities are discussed, with special reference to their biologic basis.

Animals↗
PubMed2002

[Leaf anatomy of the subtribe Conceveibinae (Euphorbiaceae)].

A comparative study of the leaf anatomy of the subtribe Conceveibinae was carried out. Leaves show a similar structural arrangement in all species, however, there are small variations among the taxa that allow definitions of species or groups. It is not possible to recognize infrageneric divisions or to maintain some genera as different from Conceveiba. The analysis included the study of 11 characters of taxonomic importance of the leaf: the form, the size and the apex of the papillae of the lower side of the blade, the number of layers of the palisade parenchyma, the presence or absence of the midrib pith, the number of vascular bundles of petiole as well as the central cylinder and the medulla, and the presence or absence of the sclerenchyma in the different levels of the petiole. The results are evaluated from a taxonomical point of view. With leaf anatomy characters only, it is possible to separate the genus Conceveiba in the subtribe.

Euphorbiaceae↗
PubMedDate not supplied

[Comparative genetics and evolutionary morphology of symbiosis formed by plants with nitrogen-fixing microbes and endomycorrhizal fungi].

Results of comparative morphological and genetic analyses are described for two major plant-microbe endosymbioses: N2-fixing nodules (with rhizobia or actinomycetes Frankia) and arbuscular mycorrhiza (with Glomales fungi). Development from the primordia formed de novo in root tissues is common for all known types of N2-fixing nodules. However, their structure varies greatly with respect to: (i) tissue topology (location of vascular bundles is peripheral in legumes but central in non-legumes); (ii) position of nodule primordium (inner or outer cortex in legumes, whereas pericycle in non-legumes); (iii) stability of apical meristem (persistent in the indeterminate nodules, transient in the determinate ones). In addition, legumes vary in ability to form compartments harboring endosymbiotic rhizobia that can be located intercellularly (infection threads) and intracellularly (symbiosomes). Using pea (Pisum sativum) symbiotic mutants, the nodule developmental program is dissected into a range of spatially and temporarily differentiated steps composing four sub-programs (development of endosymbiotic compartments; nodule histogenesis; autoregulation of nodulation; bacteroid differentiation). The developmental mutations are suggested in some cases to reverse the endosymbiotic system into the morphologically simpler forms some of which may correspond to the ancestral stages of nodule evolution. Origination of legume-rhizobial and actinorhizal symbioses is suggested to be based on a set of preadaptations many of which had been evolved in angiosperms during coevolution with arbuscular mycorrhizal fungi (e.g. inter- and intracellular maintenance of symbionts, their control via defence-like reactions and recognition of chitin-like molecules). Analysis of parallel morphological variation in symbiotic mutants and wild-growing legume species enables us to reconstruct the major stages of evolution for N2-fixing symbioses. This evolution proceeded to a sufficient degree independently from the basic physiological function of nodules (symbiotic N2-fixation) and possibly a recruiting of plant genes that initially fulfilled various "non-symbiotic" functions into the genetic networks monitoring plant-microbe interactions.

Bacterial Physiological Phenomena↗
PubMed2001

[Studies on investigation and utilization of medicinal plant resources for sustainable development in Guizhou, China].

OBJECTIVE: To gain a clear idea of the resources of medicinal plants and their pharmaceutical identification in Guizhou, China, and to conserve, develop, and uilize them effectively. METHOD: Investigation on the spot with a statistical analysis. The technical route is "Investigation and identification-->Conservation and development-->Method, technology and ways for protection, propagation and utilization-->GAP cultivated pilot and assessment of medicinal materials and their products-->Comprehensive evaluation and results". RESULT: According to the incomplete statistics, there are 3924 varieties of medicinal materials from plants, accounting for 91.47% of the total in Guizhou. Among them there are 275 families, 1384 genera and 2987 species of vascular bundle plants, accounting for 43.1% of all species. There are 200 species of pteridophyta and 2802 spermatophyta. CONCLUSION: Investigation of wild medicine species has been proceeded, as well as introduction and research of their propagation techniques and production. Guizhou is rich in medicinal plant resources. However, their species and population are reducing progressively. Effective measures must be taken to protect the germ plasma resources and put them into rational uses for the utilization and sustainable development. Rare and endemic medicine species must be introduced for conservation, propagation and realization of GAP pilot cultivation. Resources must be used in an economical way and products must be made with a high technological content.

China↗
PubMed2002

Mixed infection of black currant (Ribes nigrum L.) plants with Blackcurrant reversion associated virus and rhabdovirus-like particles with symptoms of black currant reversion disease.

Black currant plants of cvs. Black Smith and Karlstejnský dlouhohrozen showing symptoms of severe Russian (R) form of black currant reversion disease (BCRD) were found in 1999-2000 in the Czech Republic. Five selected plants of both cultivars originating from two distant loci were tested by polymerase chain reaction (PCR) for presence of the Blackcurrant reversion associated virus (BRAV), the causal agent of BCRD. In all plants, virus-specific 215 nt cDNA fragments proving the presence of BRAV were obtained. Moreover, in two of those five black currant plants, rhabdovirus-like particles were found in ultrathin sections by electron microscopical examinations. The particles measured 200-347 nm by 64-90 nm. They occurred mostly within nuclei of parenchyma cells of vascular bundles as single particles, rafts of particles, but also in aggregates. They were found also in the perinuclear space and occasionally directly in the cytoplasm. Clusters of particles either within the nucleus or in the perinuclear space were membrane-bound. We bring evidence on the occurrence of the severe (R) form of BCRD and the first evidence of BRAV in the Czech Republic.

Electrophoresis↗
PubMedDate not supplied

[Electro-osmotic phenomena in plant tissues].

The effect of a direct electric current on electrolyte transport through plant tissues was studied by applying it to 10-mm fragments of the mesocotyls of etiolated maize seedlings, similar fragments of one-year linden shoots with the normal conducting system and without vascular bundles, and isolated elements of the xylem and cell wall segments. At the current density and voltage of 9-38 microA/mm2 and 10-20 V, electrolyte solutions in plant tissues always moved toward the cathode. The results suggest that electroosmosis is one of the factors responsible for changes in solution transport through the conducting plant tissues that occur under the effect of electric current.

Biological Transport↗
PubMed2003

[Research on microscopic structure of stem and leaf of Lysimachia decurrens].

OBJECTIVE: This paper reported microscopic characters of Lysimachia decurrens. The results showed that secretory canals were scattered in the cortex, pericycle fibres arrayed annularly and pith was large with many secreory canals in the transverse section of the stem. It also showed radiate cuticula grains and round oil cells were found in the upper epidermis cells of leaf, which was bifacial and contained two midrib vascular bundles, one much bigger than the other.

Plant Leaves↗
PubMed2003

[Disarticulation of the knee joint].

PURPOSE OF THE STUDY: The authors report their experience with exarticulation in the knee joint, describe the relevant surgical procedure, assess the outcomes of different modifications of the surgical treatment and emphasize the advantages of the stump following exarticulation in the knee joint. MATERIAL: The sample included 19 patients, 13 women and 6 men, operated on in the period from 1987 to 2001. One of the women had bilateral surgery. Their average age at the time of surgery was 48 years, the range was 5 to 82 years. In most of the patients, exarticulation in the knee joint was indicated because of a malignant tumor in the crux region that could not be treated by any radical but, at the same time, limb-saving procedure. Other indications included an infected allograft of the tibia, chronic osteomyelitis of the tibia complicated by spinocellular carcinoma in a fistula, a stump after high amputation in the tibia that could not be fitted with a prosthesis, chronic lymphedema and diabetic microangiopathy. METHODS: Exarticulation is an amputation of the peripheral part of a limb in a joint, i.e., without cutting bone. The authors used a modified Rogers' procedure. Under the use of a tourniquet, a ventral incision, 10 cm long, was run from the articular fissure level distally and a dorsal incision, 5 cm long, was cut distal to the articular fissure. This produced a longer ventral and a shorter dorsal flap. The subsequent procedure included the discission of the ligamentum patellae at the tibial attachments, the articular capsule, m. sartorius, m. gracilis, m. semitendinosus, m. semimembranosus and biceps femoris, all cut at their distal attachments, as well as the tractus iliotibialis. The collateral and cruciate ligaments were incised at their femoral attachments. After dissection of the neuro-vascular bundle, the vessels were incised and double ligated. The n. tibialis and n. peronaeus were infiltrated with mesocaine and cut through. Then the m. popliteus, ligamentum popliteum arcuatum and the two heads of the m. gastrocnemius were incised and the crux separated. After removal of the pneumatic tourniquet, bleeding was arrested. The condyles, patella and synovialis were left intact. The ligamentum patellae was sutured to the tendons of the m. semimemranosus, m. semitendinosus and biceps femoris. The m. satorius and m. tractus iliotibialis were sutured to the extensor apparatus. The layer after layer was sutured with individual stitches and two Redon's drains were inserted below the fascia. RESULTS: Five patients were referred back to the initial hospital. Of six patients who died, five developed complications due to dissemination of the underlying malignant disease and one died of causes unrelated to the major disease. Eight patients were followed up at regular intervals. Of these, seven were satisfied with their stump and only one patient complained of pressure sores and therefore changed prosthetic care. Patients' complaints that would lead to repeat operations or amputation in the femur were not recorded. DISCUSSION: The surgical technique described is fast, gentle in terms of tissue damage and relatively easy to perform. All patients in the group showed good healing. The authors point out that the stump achieved by exarticulation has good weight-bearing qualities because of a large surface controlled by strong musculature that can maintain muscular balance and control the rotation of a prosthesis. The results of this study are in agreement with the data published in the English, German and Russian literature. In the Czech literature, this issue has not been reported yet. CONCLUSIONS: The advantages of exarticulation in the knee joint are as follows: quick, gentle and uncomplicated surgical procedure with low blood losses; good potential for per primam healing; high quality of the stump surface to be fitted with a prosthesis; current availability of good quality prostheses that are easier to fit than those applied after high amputation in the crux with a stump less than 11 cm or after low amputation in the femur.

Adolescent↗
PubMed2000

Radiological presentation of pulmonary calcinosis: case report.

A 64-year old man presented to the Department of Radiology for evaluation. He had a seven year history of chronic cough. The chest x-ray (CXR) done showed high density diffuse cotton wool parenchymal opacities in both lungs sparing the pleura and broncho vascular bundles. These were also demonstrated on CT. This type of pulmonary calcinosis did not fit in with the classical appearances.

Calcinosis↗
PubMed2003

[Sjören's syndrome with infiltrative lung disease showing upper lung field predominance].

We report two cases of Sjören's syndrome (SjS) with infiltrative lung disease showing upper lung field predominance. Case 1 was seen in a 68-year-old woman, who was admitted with dyspnea on exercise. Chest CT scanning demonstrated a central predominance of irregularly shaped consolidation with tractionectasis, distributed along the broncho-vascular bundles in both upper lobes. Case 2 occurred in a 70-year-old woman, who was admitted with cough. Chest CT scan showed a central predominance of irregularly shaped opacities with multiple small cystic structures in both upper lobes. Both cases were shown to be nonspecific interstitial pneumonia (NSIP) by video-assisted thoracoscopic lung biopsy, in which lung involvements were distributed around the bronchovascular sheath with relative sparing of the subpleural region. Although neither case complained of sicca symptoms, decreased saliva production was detected using the Saxon test, and further examinations revealed the presence of primary SjS. Pulmonary involvement in SjS is variable, and distribution along the broncho-bronchioles in the majority of the upper central lung field is a characteristic appearance of SjS lung disease. In patients with such patterns in chest radiography, further diagnostic differentiation should be conducted to confirm or rule out SjS.

Aged↗
PubMed1992

[Brachial plexus block by the axillary route. Cannulation of the neurovascular sheath with a G22 spinal needle. Our experience with 100 cases].

The aim of this study was to evaluate the utility of the brachial plexus block using an axillary route employing the technique in which the needle is inserted into the sheath at an angle parallel to the neuro-vascular bundle with a sole modification: using a G22 spinal needle and without evoking paresthesia. The results obtained show that this method ensures an improved and more widespread analgesia. The flexibility and small size of the G22 spinal needle allow traumas to the axillary guaina and brachial plexus to be reduced to a minimum. In addition its length enables the anesthetic solution to be diffused around the first rib, including the axillary and musculo-cutaneous nerves, thus ensuring e total sensory and motor block of the upper limb.

Adult↗
PubMed1992

[Fractures of the clavicle and secondary lesions of the brachial plexus].

The fractures of the clavicle are fundamentally minor and usually will heal by simple immobilization. When the trauma is severe, the fracture may cause a lesion of the subclavicular neuro-vascular bundle. However, if the lesion is limited it may appear clinically only a few days after the accident. In other cases, whether the clavicular fracture heals or not, the bone lesion may produce a hypertrophic callus. This phenomenon will cause a narrowing of the costo-clavicular outlet and a compression of the neurovascular bundle which will provoke a real TOS. The authors present 16 cases of clavicular fractures, two of which having had early neurovascular complications and the 14 others a late phenomenon of costo-clavicular syndrome. The pathogenesis of the lesions, the principles of treatment and the results are discussed.

Adult↗
PubMed1992

[Changes in the glial condition in different sections of the rat brain after stopping the systemic circulation].

The effect of ischemia on the expression of GFAP in astrocytes of cerebrum, hippocampus and cerebellum was studied on rat clinical death model. Cardiac arrest was induced by 10-or 15-min intrathoracic compression of the heart vascular bundle. Immunohistochemical staining showed that GFAP immunoreactivity significantly increased in the white matter, and GFAP-expressing astrocytes appeared in the gray matter. The reaction activity correlated with ischemia duration and phases of postresuscitation process. The obtained data are indicative of possible changes in the astrocytes condition in the absence of manifest lesions of neurons. This brings up the question of the role of glia homeostasis derangements in the formation of brain postresuscitation pathology.

Animals↗
PubMed1992

[Abnormal chest shadow on CT in immunosuppressed patients].

An abnormal chest shadow was observed on CT scans in 25 cases of 23 immunosuppressed patients. Pulmonary disease was pathologically confirmed to be pneumocystis carinii pneumonia (PC pneumonia) in four patients, cytomegalovirus pneumonia (CMV pneumonia) in one, bacterial pneumonia in seven, fungal infection in three, miliary tuberculosis in one, leukemic infiltration in two, lymphangitis carcinomatosa in three, drug-induced pneumonitis in three, and ARDS in one. In almost all patients, especially those with infectious diseases such as PC pneumonia, CMV pneumonia, and bacterial pneumonia, the abnormal shadow was wide and visible in the bilateral lung fields. We presumed that such findings as lobular shadow, centrilobular shadow, and mosaic pattern reflected the extension of disease via the respiratory tract, and that those findings are typical of infectious diseases. Because such findings as abnormal linear shadow and swelling of a broncho-vascular bundle were very frequently recognized in patients with lymphangitis carcinomatosa and frequently recognized in those with drug-induced pneumonitis, these diseases may be distinguished from other diseases. An area of slightly increased density was frequently recognized in patients with PC pneumonia, bacterial pneumonia, and drug-induced pneumonitis. Such lesions were pathologically confirmed to be located in the interstitium and/or alveolus. CT was extremely useful in comprehending the character and extension of particular diseases among various diseases. As the number of patients studied was small, the utility of CT in immunosuppressed patients requires further investigation in a larger number of patients.

Adolescent↗