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At least 55 records · Page 3Linked to original sources

PubMed1998

Protective Effects of Iganidipine on Morphological and Functional Changes of Arteries in Hypertensive Dahl Rats.

BACKGROUND: This study was performed to examine the protective effects of iganidipine, a new water-soluble calcium antagonist, on the morphological and functional changes of arteries in Dahl salt-sensitive (Dahl-S) rats. METHODS AND RESULTS: Vehicle and iganidipine were administered orally to Dahl-S rats fed a high-salt diet (HSD) for 8 weeks. Aorta, superior mesenteric arteries (SMA), and peripheral mesenteric arteries (PMA) were examined light-microscopically or electon-microscopically. Relaxant responses of isolated aorta and SMA were recorded isometrically. In rats fed HSD, blood pressure was markedly increased. Light microscopy showed intimal and medial hypertrophy, periarteritis, and narrowed arterial lumen in the PMA. Transmission and scanning electron microscopy or light microscopy showed medical thickness in the aorta and SMA and hypertrophy of endothelial cells and dilatation of the subendothelial space only in the aorta. In the SMA, both endothelium-dependent relaxation (EDR) and endothelium-independent relaxations (EIR) were reduced to a similar extent. In the aorta, the EDR was more markedly attenuated than the EIR. Iganidipine at 3 mg/kg/day showed a 24-h sustained hypotensive effect and completely prevented the morphological and functional changes in both arteries. Iganidipine at 1 mg/kg/day, which lowered blood pressure only for several hours, decreased the injuries in PMA and aortic endothelium and moderately restored the EDR in the aorta. Iganidipine at 0.3 mg/kg/day had no effects. CONCLUSIONS: In Dahl-S rats fed an HSD, iganidipine completely prevented all the changes at a sustained-hypotensive dose and prevented the injuries of PMA and aortic endothelium and the reduction of EDR in the aorta at a nonsustained hypotensive dose. Nonhemodynamic effects of iganidipine may be partly involved in its protective effects against arterial injuries.

Journal Article↗

PubMed2003

Half pitch lower sound perception caused by carbamazepine.

We report a 16-year-old woman with secondary generalization of partial seizure, who complained of an auditory disturbance after carbamazepine (CBZ) administration. She had been taking sodium valproate (VPA) from the age of 15. However, her seizures remained poorly controlled. We changed her antiepileptic drug from VPA to CBZ. At 1 week after CBZ administration, she noticed that electone musical performances were heard as a semitone lower. When oral administration of CBZ was stopped, her pitch perception returned to normal. If she had not been able to discern absolute pitch, she might have been unable to recognize her lowered pitch perception. Auditory disturbance caused by CBZ is reversible and very rare.

Adolescent↗

PubMed1975

Scanning electron microscopy of glucocrticoid-treated hepatocytes and hepatoma cells in culture.

The morphological effects of exposure to hydrocortisone have been examined in two cell lines of liver origin by scanning electon microscopy. In one of these, an aneuploid line derived from a Morris hepatoma, the presence of hormone results not only in a suppression of cell proliferation, but in a marked flattening of the cells and loss of surface microvilli; in the other cell line, a diploid line derived from adult rat liver, the suppression of cell division is less marked, and the morphological effects of the hormone are far less striking. While the suppression of cell division in both of these cell lines is known to be rapidly reversible upon the removal of hormone, the presence of hormone causes the hepatoma cells to assume both monolayer growth characteristics and a morphology resembling those of cells derived from normal liver.

Animals↗

PubMed2003

Expression of hepatitis B virus X protein in transgenic mice.

AIM: To establish a mice model harboring hepatitis B virus x gene (adr subtype) for studying the function of hepatitis B virus X protein, a transactivator of viral and cellular promoter/enhancer elements. METHODS: Expression vector pcDNA3-HBx, containing CMV promoter and hepatitis B virus x gene open reading fragment, was constructed by recombination DNA technique. Hela cells were cultured in DMEM and transfected with pcDNA3-HBx or control pcDNA3 plasmids using FuGENE6 Transfection Reagent. Expression of pcDNA3-HBx vectors in the transfected Hela cells was confirmed by Western blotting. After restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes. The pups were evaluated by multiplex polymerase chain reaction (PCR) at genomic DNA level. The x gene transgenic mice founders were confirmed at protein level by Western blotting, immunohistochemistry and immunogold transmission electron microscopy. RESULTS: Expression vector pcDNA3-HBx was constructed by recombination DNA technique and identified right by restriction endonuclease digestion and DNA direct sequencing. With Western blotting, hepatitis X protein was detected in Hela cells transfected with pcDNA3-HBx plasmids, suggesting pcDNA3-HBx plasmids could express in eukaryotic cells. Following microinjection of coding sequence of pcDNA3-HBx, the embryos were transferred to oviducts of pseudopregnant females. Four pups were born and survived. Two of them were verified to have the HBx gene integrated in their genomic DNA by multiplex PCR assay, and named C57-TgN(HBx)SMMU1 and C57-TgN(HBx)SMMU3 respectively. They expressed 17KD X protein in liver tissue by Western blotting assay. With the immunohistochemistry, X protein was detected mainly in hepatocytes cytoplasm of transgenic mice, which was furthermore confirmed by immunogold transmission electon microscopy. CONCLUSION: We have constructed the expression vector pcDNA3-HBx that can be used to study the function of HBx gene in eukaryotic cells in vitro. We also established HBx gene (adr subtype) transgenic mice named C57-TgN (HBx)SMMU harboring HBx gene in their genome and express X protein in hepatocytes, Which might be a valuable animal system for studying the roles of HBx gene in hepatitis B virus life cycle and development of hepatocellular carcinoma in vivo.

Animals↗

PubMed2001

Familial amyotrophic lateral sclerosis and parkinsonism-dementia complex of the Kii Peninsula of Japan: clinical and neuropathological study and tau analysis.

We report the first case of neuropathologically verified parkinsonism-dementia complex of the Kii peninsula, together with the patient's brother, who had amyotrophic lateral sclerosis. The propositus woman developed parkinsonism and dementia at 63 years of age and died at 70 without displaying clinical features of amyotrophic lateral sclerosis. The brain exhibited marked atrophy of the frontal and temporal lobes. Microscopically, there were many neurofibrillary tangles in the central nervous system, most markedly in the mesial temporal lobe and deep nuclei, as well as changes of amyotrophic lateral sclerosis but no senile plaques or Lewy bodies. Neurofibrillary tangles exhibited twisted tubule structures on electon microscopic examination, and an analysis of insoluble tau protein extracted from the fresh brain revealed a 60-, 64-, 68-kD triplet. The tau gene exhibited no mutations. Her brother developed progressive bulbar palsy-type amyotrophic lateral sclerosis at 45 years of age and died at 49 without presenting with dementia or parkinsonism. Neuropathological examination revealed not only pathologic features of amyotrophic lateral sclerosis but also a moderate number of neurofibrillary tangles in the temporal cortex and deep nuclei. The siblings were neuropathologically similar despite their different clinical manifestations. These findings suggest that amyotrophic lateral sclerosis and parkinsonism-dementia complex of this family may be phenotypic variants of a tauopathy caused by genetic abnormalities.

Aged↗

PubMed2001

[Detection of Cre recombinase activity in Mx-Cre transgenic mice induced by INF in vitro].

The Cre recombinase and its activity in C57-TgN(Mx-Cre) transgenic mice is studied by polymerase chain reaction (PCR), Western blot, immunohistochemistry, immunogold electron microscopy and Southern blot. C57-TgN(Mx-Cre) transgenic mice harbouring cre gene in genomic DNA is demonstrated by PCR, and these mice which are induced by INF-alpha 1b could express Cre recombinase, which is confirmed by Western blot. With immunohistochemistry, we find that the Cre recombinase expresses in hepatocyte cytoplasm and nuclear of C57-TgN(Mx-Cre) transgenic mice. Cre recombinase expressed in hepatocyte cytoplasm and nuclear is further confirmed by immunogold electon microscopy. And it is supported that the Cre recombinase which is created from C57-TgN(Mx-Cre) transgenic mice induced by INF-alpha 1b can direct DNA recombination reaction in vitro. All evidence leads us supporting the view that the Cre recombinase expressed in C57-TgN(Mx-Cre) transgenic mice has activity. Thus we find a method to detect the activity of Cre recombinase in vitro.

Animals↗

PubMed1975

[Eye changes in diabetes mellitus].

In ophthalmological examinations on 820 diabetics in 32% a diabetic retinopathy I or II was found. The frequency of retinopathy correlates with the duration of diabetes. A glaucoma (4.8%) or an increased intra-ocular pressure, respectively, was statistically significantly more frequent in diabetics than in the total population. Among 714 patients with glaucoma about 17% of diabetics were found. Compared with the morbidity of diabetes of adequate age groups of the total population this is statistically significant. The intraocular pressure of patients with glaucoma and diabetes is therapeutically worse to be influenced than in patients with glaucoma without diabetes. They need a particularly attentive control and therapy. By means of electon-microscope examinations as a possible cause for the association of glaucoma and diabetes mellitus similar changes in the iridocorneal angle could be found in the two diseases.

Adult↗

PubMed1999

[INDO/CI studies on the electronic spectra of tetraphenylporphyrin and its derivatives].

MNDO calculations and group theory were carried out on tetraphenylporphyrine (TPP) to obtain its optimum molecular geometry. We employed an INDO/CI method to study the electronic structures of tetraphenylporphyrine and its derivatives and identify their main electonic absorption bands. Five-orbital model was advanced to explain the typical characteristics of electronic spectra of H2TPP and its derivatives. The calculated wavelengths were in good agreement with the experimental values. The effects of the substitution of variant group were discussed and some helpful conclusions were drawn.

Models, Molecular↗

PubMed1979

[Histological and electron microscopic study of the cerebral cortex of the progeny of neurosensitized rats].

The sensomotor brain cortex of 30-day ratlings born by preliminary neurosensitized females, was studied. The studies demonstrated retardation in the development of the brain cortex in the progeny. Electon microscopic examinations detected certain features in the structure of cellular organella, as well as membrane formations in the nuclei of the cortical neurons. These changes are considered as an expression of a lowered level of neuron functioning.

Animals↗

PubMed1977

[Histomorphometric studies on the influence of long-term calcitonin therapy on osteodystrophia deformans Paget].

Bone alterations in Paget's disease, have been studied by histomorphometrical evaluation iliac creat bone biopsies before and after long-term treatment with human ans salmon calcitonin. Therapeutic effect was controlled from 12, up to 48 months. All-together 28 bone biopsies were taken from 9 patients (aged 46 to 71 years) with Paget's disease of their os ileum. The biopsies were prepared for histological examination without previous decalcification, cut, stained and quantitatively analysed at the light microscopic level. By means of a point counting method we determined the parameters of bone structure, bone formation and bone resorption. Before therapy was started, trabecular bone alterations could be observed which were typical for Paget's disease of bone as there were bulky trabeculare, increased remodelling surfaces and giant osteoclasts. Following treatment with calcitonin a dramatic reduction of bone remodelling surfaces and a normalization of bone structure occurs. Considering our previous electon microscopy findings, a reduction of the number of osteoclasts as well as their nuclear content, might be explained by an inhibitory effect of calcitonin on cell fusion of osteoclastic precursor cells. In 2 cases, an interruption or hormonal treatment of 5 to 12 months, presented no risk of losing the therapeutic effect.

Aged↗

PubMed1980

Controlled microstructure of two stage polyhydroxyethyl methacrylate coatings on polyethylene terephthalate substrates for potential prosthetic applications.

Two types of polyethylene terephthalate (Dacron) substrates (USCI DeBakey Vasculour-D and USCI Sauvage filamentous) have been selectively coated with Poly-hydroxyethyl methacrylate (P-HEMA) in a two-stage process. Using scanning electon microscopy (SEM) techniques, the microstructural details of the fabrications were identified. The first stage of this process imparted a coating of P-HEMA having a heterogeneous macroporous structure and the second stage yielded an internal surface coating of hydrogel with a homogeneous microporous surface structure. The morphology on a colloidal level was controlled by adjustment of the cosolvent ratios holding other fabrication parameters constant. These microstructural features coupled with the chemical properties of the hydrogel suggest potential medical prosthetic applications. The results of initial canine carotid artery implantations indicate that an endothelial-like cell layer can be established within 21 days on the luminal surface of specific hydrogel impregnated Dacron knitted prosthetic materials. The chemical and morphological properties of a hydrogel impregnated Dacron prosthesis may present a blood flow surface which allows proper conditioning protein and cellular deposition leading to an accelerated endothelial development without the need to preclot the prosthesis wall.

Acrylates↗

PubMed1996

Rate of keratinization of the wall segment of the hoof and its relation to width and structure of the zona alba (white line) with respect to claw disease in cattle.

OBJECTIVES: To determine contribution of the wall segment of bovine cattle hoof to horn production, and relevance of structural differences of the wall segment and its horn production rate to claw disease. DESIGN: Epidermis and papillary body of the wall segment were examined by mesoscopy, light microscopy, and transmission and scanning electron microscopy. Morphometry of the entire length of the zona alba was examined, and the horn production rate of the wall segment was calculated. ANIMALS: Mixed-breed, dual purpose (beef and dairy) cattle of either sex, and young (20 months) Holstein-Friesian beef bulls. PROCEDURE: Blocks of a strip of the hoof from the coronary segment to the sole margin, including epidermis and dermis, were prepared for light and transmission electon microscopy. Prepared specimens of the wall-sole border were examined by scanning electron microscopy. Morphometry was performed on the outer, middle, and inner parts of the zona alba structures on unfixed horn specimens of beef bull claws. After removal of the zona alba specimens, the claw was removed and the proximodistal extent of the epidermal leaflets was measured and analyzed statistically. RESULTS: Horn production increased in the distal half of the wall segment, was greatest at the wall-sole border, and highest above the abaxial end of the zona alba. High horn production resulted in an incompletely keratinized, softer horn. CONCLUSIONS AND CLINICAL RELEVANCE: High horn production at the zona alba increases susceptibility to vascular disturbance. Claw dyskeratoses appear first in areas of high horn production, areas which are also subject to a greater frequency of claw lesions.

Animals↗

PubMed1962