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PubMed1991

Organ-specific invertase deficiency in the primary root of an inbred maize line.

An organ-specific invertase deficiency affecting only the primary root system is described in the Oh 43 inbred maize (Zea mays). Invertases (acid and neutral/soluble and insoluble) were assayed in various tissues of hybrid (NK 508) and inbred (Oh 43, W 22) maize lines to determine the basis for an early report that Oh 43 root tips were unable to grow on sucrose agar (27). Substantial acid invertase activity (7.3 to 16.1 micromoles of glucose per milligram of protein per hour) was evident in extracts of all tissues tested except the primary root system of Oh 43. This deficiency was also evident in lateral roots arising from the primary root. In contrast, morphologically identical lateral roots from the adventitious root system had normal invertase levels. These results suggest that ontogenetic origin of root tissues is an important determinant of invertase expression in maize. Adventitious roots (including the seminals) arise above the scutellar node and are, therefore, of shoot origin. The Oh 43 deficiency also demonstrated that invertase activity was not essential for maize root growth. Sucrose synthase was active in extracts from all root apices and theoretically provided the only available avenue for sucrose degradation in primary root tips of Oh 43. The deficiency described here will provide a useful avenue of investigation into the expression and significance of root invertase.

Journal Article↗
PubMed1986

[Non-invasive evaluation of right ventricular pressure in children with heart diseases: quantitative assessment by thallium myocardial imaging].

201-thallium myocardial imaging studies were performed to evaluate systolic pressures in the right ventricle of 194 patients. These patients were classified to four groups. Group A (95 cases) consists of 77 patients with congenital cardiac disease, five patients with primary pulmonary hypertension, and 13 patients with history of MCLS. Congenital cardiac diseases included 30 patients with tetralogy of Fallot, 20 with ventricular septal defect, nine with atrial septal defect, and eight with pulmonary stenosis. Group B (35 cases); preoperative state of transposition of the great arteries. Group C (43 cases); post-operative state of congenital cardiac disease whose pre-operative right ventricular systolic pressures represented more than 70% of the left ventricular systolic pressures. This group included 31 patients with tetralogy of Fallot, seven with ventricular septal defect, four with atrial septal defect and one with patent ductus arteriosus. Group D (21 cases); post-operative state of transposition of the great arteries. Fifteen min after intravenous infusion of 30-50 microCi/kg 201-TlCl, myocardial images were obtained in five projections (anterior, LAO 30 degrees, 45 degrees, 60 degrees, and lateral). The angles were determined to demonstrate clearly the interventricular septum and the ventricular free wall. The images of end-diastolic phase were obtained using the ECG-synchronized gated method in each projection. The region of interest (ROI) was defined as a section or slice by drawing two lines perpendicular to the septum, and the counts of the systemic and pulmonic ventricular free wall (Cs and Cp) were analyzed to evaluate the pressure of the pulmonic ventricle. The pressures of the ventricles were obtained by cardiac catheterization performed concomitantly with the cardiac imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1976

Electron microscopy of postmortem autolysis of rat muscle tissue.

To define the progression of ultrastructural changes in normal muscle at post mortem, rat gastrocnemius muscles were studied at various times after storage at +4 degrees C and +22 degrees C. Degeneration of the I-zone (discoid necrosis) and membranous bodies were found to be similar to that seen in muscle diseases, and lamellar formations were seen in mitochondria. At +4 degrees C there was contraction of the sarcomere which vanished in 12 h and inter-filamentous oedema appeared. Z-line degeneration was seen at 24 h and at 4 days all Z-lines had disappeared, and the H-zone showed darkening. In the same samples collapse or ruptures of the I band were seen. At 8 days the H-zones and M-lines were still discernible. In the early stages the mitochondria showed swelling and loss of matrix granules, while later they showed broken cristae and outer membranes, and flocculent densities. At 4 days rearrangement of the cristal material into long pentalaminar "needles" was seen in a few mitochondria. At 4 and 8 days membranous bodies were seen and the T-system and sarcoplasmic reticulum showed ruptures and disintegration into vesicles. The nucleus showed increasing condensation of chromatin at the periphery and clearing of the center. Polysomes and glycogen were reduced at 2 h, and has practically vanished at 24 h. At 22 degrees C the changes were the same but appeared about 4 times as quickly as at +4 degrees C.

Animals↗
PubMed2005

[In vitro infection of human hepatoma (Hep G2) cell line by hepatitis B virus positive serum].

OBJECTIVE: To establish a culture system of HBV positive serum infected Hep G2 cells in vitro. METHODS: Hep G2 cells were seeded into six-well cluster dishes, at 1 x 10(-6) cells per well and incubated with 3 ml 10% fetal calf serum/ Dulbecco's modified Eagle's medium (10% FCS/DMEM) at 37 degrees in 5% CO2 air. At 24 h after plating, infection group Hep G2 cells were cultured with 0.5 ml HBV positive serum, in control group HBV negative serum was used, 24 h later the inoculums was removed. The cells were then extensively washed with 0.01 mol/L phosphate-buffered saline (PBS). After washing with PBS, 4 ml 2% FCS/DMEM were added to each well and the medium was collected every 12 h. ELISA method was used to detect HBsAg in culture medium. HBV DNA in cells and culture medium was detected by PCR. RESULTS: In infection group, HBsAg could be detected from cell culture medium from 12 h (after PBS washed) to 84 h. HBV DNA could be detected by PCR in culture medium and cells. CONCLUSION: Infection of Hep G2 cells by HBV positive serum is feasible.

Carcinoma, Hepatocellular↗
PubMed2026

Quantitative trait locus qLDC5 regulates primary root branching in an auxin-dependent manner.

L-type lateral root (LLR) density determines root system architecture, affecting nutrient acquisition in rice (Oryza sativa L.), particularly under low-phosphorus conditions. Previous studies identified genotypic differences in LLR density and a quantitative trait locus (QTL) enhancing LLR density on crown roots (qLDC5). We showed that LLR densities on crown and primary roots were closely correlated and confirmed higher LLR density on primary roots in qLDC5 donor DJ123 compared with the African variety NERICA4 using X-ray micro-computed tomography. We confirmed the qLDC5 effect in a field experiment for LLR density on primary roots. LLR densities on primary and crown roots, therefore, appear under similar genetic control. Developmental analyses revealed that DJ123 and NDJ188-a derivative line harboring qLDC5-initiate more lateral root primordia than NERICA4, with a higher proportion progressing to elongation, but that exogenous auxin application reversed this ranking. Within qLDC5, auxin biosynthesis gene OsYUCCA2 and auxin response factor OsARF15 were up-regulated in DJ123. Transcriptome analysis revealed an indirect auxin-mediated regulatory network underlying LLR variation. Differentially expressed genes in DJ123 and NDJ188 were enriched for ent-kaurene and gibberellin metabolism, including the robust induction of OsGA2ox5. These findings suggest qLDC5 increases lateral root density by coordinating gibberellin, auxin, and terpene pathways.

Oryza↗
PubMed2001

Phylogeny and ontogeny of the lymphatic stomata connecting the pleural and peritoneal cavities with the lymphatic system--a review.

This paper reviews the phylogeny and ontogeny of "lymphatic stomata" through which fluids and cells in the pleural and peritoneal cavities enter the lymphatic system. In amphibians, the pleuroperitoneal cavity is connected through numerous pores with the wide subvertebral lymphatic sinus corresponding to the thoracic duct in mammals. In reptiles, direct connections of the pleural and peritoneal cavities with the lymphatic system have been reported. In mammals, the pleural and peritoneal cavities are directly connected with lymphatics through lymphatic stomata. How do lymphatic stomata develop in mammals? In the rat, distinct lymphatics are noted in the subpleural space of the diaphragm periphery in 16 days old embryo. With age, the supleural lymphatics increase and form a polygonal network. They show a tubular appearance and possess many valves. Some of them become endowed with smooth muscle cells. In 19 days old embryos, some lymphatics appear in the subperitoneal space of the diaphragm. They extend centripetally and form many lateral projections that later elongate and connect with those from adjacent lymphatics, thus forming a lattice-like network or "lymphatic lacunae". During early postnatal days, the lymphatic lacunae project many bulges that subsequently come into contact with the pores among mesothelial cells lining the diaphragmatic peritoneum, thus forming lymphatic stomata. They increase until postnatal week 10. The lymphatic stomata in the costal pleura also develop during early postnatal days.

Aging↗
PubMed1992

Immune regulation in self tolerance: functional elimination of a self-reactive, counterregulatory CD8+ T lymphocyte circuit by neonatal transfer of encephalitogenic CD4+ T cells lines.

Transfer of encephalitogenic, CD4+ T lymphocyte lines into syngeneic adult Lewis rats not only leads to the development of experimental autoimmune encephalomyelitis (EAE), but, in addition, to the expansion of counterregulatory, CD8+ T lymphocyte clones which are able to lyse specifically the encephalitogenic T cells in vitro and to neutralize their encephalitogenic capacity in vivo. In striking contrast, in neonatal rats, which still lack myelin (autoantigens), injection of the same encephalitogenic lines neither mediates EAE, nor confers protection in later life against the myelin-specific T cells. In fact, this treatment results in the life-long functional elimination of counterregulatory, clonotypic CD8+ T lymphocytes, which cannot even be reinduced by repeated injections of the relevant CD4+ T line. These data seem to point to a self-protective T cell control mechanism which is developed within the immune system prior to, and thus independent of the appearance of the appropriate self antigen.

Animals↗
PubMed2005

Adaptation of estrogen-regulated genes in long-term estradiol deprived MCF-7 breast cancer cells.

First line treatment of hormone dependent breast cancer initially causes tumor regression but later results in adaptive changes and tumor re-growth. Responses to second line treatments occur but tumors again begin to progress after a period of 12???18??months. In depth understanding of the adaptive process would allow the identification of targets to abrogate the development of hormonal resistance and prolong the efficacy of endocrine therapy. We have developed a model system to examine adaptive changes in human MCF-7 breast cancer cells. Upon deprivation of estradiol for a prolonged period of time, a maneuver analogous to surgical oophorectomy in pre-menopausal women and use of aromatase inhibitors in post-menopausal patients, tumor cells adapt and become hypersensitive to estradiol. We reasoned that the expression pattern of multiple genes would change in response to estradiol deprivation and that cDNA microarrays would provide an efficient means of assessing these changes. Accordingly, we examined the transcriptional responses to estradiol in long-term estradiol deprived (LTED) MCF-7 cells with a cDNA microarray containing 1901 known genes and ESTs. To assess the changes induced by long-term estradiol deprivation, we compared the effects of estradiol administration in LTED cells with those in MCF-7 cells, which we had previously reported, and confirmed with real time PCR using the parental and LTED cells. Seven genes and one EST were induced by estradiol in LTED but not in wild type MCF-7 cells, whereas ten genes were down-regulated by estradiol only in LTED cells. The expression of seven genes increased concurrently and five decreased in response to estradiol in both cell types. From these observations, we generated testable hypotheses regarding several genes including DKFZP, RAP-1, ribosomal protein S6, and TM4SF1. Based upon the known functions of these genes and the patterns of observed changes, we postulate that divergent regulation of these genes may contribute to the different biologic responses to estrogen in these cell lines. These results provide targets for further mechanistic studies in our experimental system. Our findings indicate that long-term estradiol deprivation causes expression changes in multiple genes and emphasizes the complexity of the process of cellular adaptation.

Adaptation, Physiological↗
PubMed1984

Structural asymmetries in brains of mice selected for strong lateralization.

The brains of 18 female mice from two lines selectively bred for lateralization of paw preference were investigated for morphological asymmetries in 5 horizontal sections from mid-dorsoventral planes. Cortical thickness was measured at orbitofrontal, somatosensory and lateral entorhinal regions; volume measures included the hippocampal formation and the striatum. Mice of the strongly lateralized line had stronger asymmetries in 4 of the 5 variables. Discriminant analysis showed that the two mouse lines could be differentiated best by their asymmetries in orbitofrontal cortex and hippocampus (P less than 0.02).

Animals↗
PubMed1986

Synergistic effects of dopamine agonists and centrally administered neurotensin on feeding.

Several lines of evidence indicate that neurotensin may modulate the activity of dopamine systems in the central nervous system. The present study investigated the possibility that intraperitoneal injections of the dopamine agonists l-dopa and bromocriptine would alter the aphagia produced by central administration of neurotensin. It was found that neurotensin suppressed feeding in food-deprived rats when injected into the lateral ventricle or the ventromedial hypothalamus. Food intake was not affected, however, when the peptide was placed in the lateral hypothalamus. A dose-dependent aphagia was also observed following peripheral injections of l-dopa and bromocriptine. Additionally, the anorectic effect of centrally administered neurotensin was potentiated by concurrent administration of doses of l-dopa or bromocriptine which, when given alone, had no effect on food intake. The data suggest that neurotensin aphagia may be mediated by the peptide's ability to increase the activity of dopamine systems in the central nervous system.

Animals↗
PubMed2001

Lessons from the glitazones: a story of drug development.

Troglitazone, the first in the thiazolidinedione class of oral hypoglycaemic agents, was launched in the USA in March, 1997. It reached Europe later that year, only to be withdrawn within weeks on the grounds of liver toxicity. Meanwhile it went on to generate sales of over $2 billion in the USA, and caused at least 90 cases of liver failure (70 resulting in death or transplantation) before it was withdrawn in March, 2000. Rosiglitazone and pioglitazone reached the US market in 1999 as first-line agents to be used alone or in combination with other drugs, but in Europe the same dossiers were used one year later to apply for a limited licence as second-line agents restricted to oral combination therapy. How should we use the glitazones? And how did they achieve blockbuster status without any clear evidence of advantage over existing therapy?

Adverse Drug Reaction Reporting Systems↗
PubMed1995

[Quantitative evaluation of the Romberg test].

Simple and economical measuring platforms are available to aid the ENT clinician in examining vestibulospinal disorders. The aim of our study was to quantitatively interpret Romberg test measurements. Calculating the area between the zero line and the curves in sagittal and lateral direction--for the Romberg test with closed and open eyes--enables a quantification of body sway. For the evaluation of data, we developed a triangular diagram which allows a graphic representation and quantifies vestibulospinal reaction at a glance. We assessed a group of 80 persons without any symptoms of peripheral or central vestibular system disturbance. Selected patients complaining of vestibular disorders are helpful in demonstrating the objective and quantitative interpretation of the Romberg test, which is often analysed in a more subjective way.

Adult↗
PubMed2002

Early restriction of peripheral and proximal cell lineages during formation of the lung.

To establish the timing of lineage restriction among endodermal derivatives, we developed a method to label permanently subsets of lung precursor cells at defined times during development by using Cre recombinase to activate floxed alkaline phosphatase or green fluorescent protein genes under control of doxycycline-dependent surfactant protein C promoter. Extensive or complete labeling of peripheral lung, thyroid, and thymic epithelia, but not trachea, bronchi, or gastrointestinal tract occurred when mice were exposed to doxycycline from embryonic day (E) 4.5 to E6.5. Nonoverlapping cell lineages of conducting airways (trachea and bronchi), as distinct from those of peripheral airways (bronchioles, acini, and alveoli), were established well before formation of the definitive lung buds at E9-9.5. At E11.5, the labeled precursors of peripheral lung were restricted to relatively few cells along the bronchial tubes and clusters in bronchial tips and lateral buds. Thereafter, these cells underwent marked expansion to form the entire gas-exchange region in the lung. This study demonstrates early restriction of endodermal progenitor cells forming peripheral as compared with proximal airways, identifies distinct cell lineages in conducting airways, and distinguishes neuroepithelial and tracheal-bronchial gland cell lineages from those lining peripheral regions of the lung. This system for conditional gene addition or deletion is useful for the study of lung morphogenesis and gene function in vivo, and identifies progenitor cells that may serve as useful targets for cell or gene replacement for pulmonary disorders.

Animals↗
PubMed1991

Restricted virus replication in the spinal cords of nude mice infected with a Theiler's virus variant.

The Daniels strain of Theiler's murine encephalomyelitis produces a chronic disease which is an animal model for human demyelinating disorders. Previously, we selected a neutralization-resistant virus variant producing an altered and diminished central nervous system disease in immunocompetent mice which was evident during the later stage of infection (after 4 weeks) (A. Zurbriggen and R. S. Fujinami, J. Virol. 63:1505-1513, 1989). The exact epitope determining neurovirulence was precisely mapped to a capsid protein, VP-1, and represents a neutralizing region (A. Zurbriggen, J. M. Hogle, and R. S. Fujinami, J. Exp. Med. 170:2037-2049, 1989). Here, we present experiments with immunoincompetent animals to determine viral replication, spread, and targeting to the central nervous system in the absence of detectable antibodies or functional T cells. Nude mice were infected orally, and the virus was monitored by plaque assay, immunohistochemistry, and in situ hybridization. Early during the infection (1 week), the variant virus induced an acute disease comparable to that induced by the wild-type virus in these nude mice. Alterations in tropism in the central nervous system were not apparent when wild-type parental Daniels strain virus was compared with the variant virus. Moreover, variant virus replicated in tissue culture (BHK-21 cells) to similarly high titers in a time course identical to that of the wild-type virus (A. Zurbriggen and R. S. Fujinami, J. Virol. 63:1505-1513, 1989). However, replication of the variant virus versus the wild-type virus within the spinal cord of athymic nude mice infected per os was substantially restricted by 6 weeks postinfection. Therefore, the reduced neurovirulence in the later stage (6 weeks) of the disease is most likely due to a diminished growth rate or spread of the variant virus in the central nervous system rather than to marked differences in viral tropism.

Animals↗
PubMed1998

Randomised, prospective study comparing cemented and cementless total knee replacement: results of press-fit condylar total knee replacement at five years.

Early implants for total knee replacement were fixed to bone with cement. No firm scientific reason has been given for the introduction of cementless knee replacement and the long-term survivorship of such implants has not shown any advantage over cemented forms. In a randomised, prospective study we have compared cemented and uncemented total knee replacement and report the results of 139 prostheses at five years. Outcome was assessed both clinically by independent examination using the Nottingham knee score and radiologically using the Knee Society scoring system. Independent statistical analysis of the data showed no significant difference between cemented and cementless fixation for pain, mobility or movement. There was no difference in the radiological alignment at five years, but there was a notable disparity in the radiolucent line score. With cemented fixation there was a significantly greater number of radiolucent lines on anteroposterior radiographs of the tibia and lateral radiographs of the femur. At five years, our clinical results would not support the use of the more expensive cementless fixation whereas the radiological results are of unknown significance. Longer follow-up will determine any changes in the results and conclusions.

Adult↗
PubMed1992

Long term evaluation of the unilink anastomotic system. A study with light and scanning electron microscopy.

The long term effects of the Unilink mechanical microvascular anastomosis in terms of anastomotic patency and histological changes in the vessel wall were evaluated in 10 rabbits. Both carotid arteries and facial veins were divided and reanastomosed with the Unilink device. At death two years later all 40 anastomoses were fully patent, with histological changes similar to those described previously after 16 weeks, that is, normal endothelial lining, but almost total atrophy of the media at the anastomotic site. The thinning of the vessel wall at the anastomosis caused neither occlusions nor aneurysms during the observation period.

Anastomosis, Surgical↗
PubMed2002

Enriched odor exposure increases the number of newborn neurons in the adult olfactory bulb and improves odor memory.

In the mammalian forebrain, most neurons originate from proliferating cells in the ventricular zone lining the lateral ventricles, including a discrete area of the subventricular zone (SVZ). In this region, neurogenesis continues into adulthood. Most of the cells generated in the SVZ are neuronal precursors with progeny that migrate rostrally along a pathway known as the rostral migratory stream before they reach the main olfactory bulb (MOB) where they differentiate into local interneurons. The olfactory system thus provides an attractive model to investigate neuronal production and survival, processes involving interplay between genetic and epigenetic influences. The present study was conducted to investigate whether exposure to an odor-enriched environment affects neurogenesis and learning in adult mice. Animals housed in either a standard or an odor-enriched environment for 40 d were injected intraperitoneally with bromodeoxyuridine (BrdU) to detect proliferation among progenitor cells and to follow their survival in the MOB. The number of BrdU-labeled neurons was not altered 4 hr after a single BrdU injection. In contrast, the number of surviving progenitors 3 weeks after BrdU injection was markedly increased in animals housed in an enriched environment. This effect was specific because enriched odor exposure did not influence hippocampal neurogenesis. Finally, we showed that adult mice housed in odor-enriched cages display improved olfactory memory without a change in spatial learning performance. By maintaining a constitutive turnover of granule cells subjected to modulation by environmental cues, ongoing bulbar neurogenesis could be associated with improved olfactory memory.

Administration, Inhalation↗
PubMed1975

[Morphogenesis of congestive fibrosis of the liver].

Genesis of the muscatel-like fibrosis of the liver was studied on section and experimental material. The methods of histological, histochemical and electron microscopy analysis were used. It was established that the rise of pressure in the system of hepatic veins in chronic cardiac decompensation was accompanied by drastic venous congestion, hemorrhages and necrosis of hepacytes in the circumference of the central and collecting veins and along the lines of their junction which resulted in inversion of the hepatic lobes. In the zones of venous congestion pericentral fibrosis developed, which occasionally may be accompanied by priportal fibrosis. At later stages, muscatel-like cirrhosis of the liver was formed. The latter was underlaid by an elevated tropocollagenous activity of cells, this activity apart from fibroplasts, may be fulfilled also by Dupffer's cells. In chronic hepatic congestion a number of compensatory-adaptive changes in the vessels may occur.

Animals↗