Biomedical subjects

N Manabe

Publications and source records attributed to N Manabe.

At least 55 records · Page 3Linked to original sources

PubMed1999

Independent impairment of osteoblast and osteoclast differentiation in klotho mouse exhibiting low-turnover osteopenia.

We recently identified a new gene, klotho, which is involved in the suppression of multiple aging phenotypes. The mouse homozygous for a disruption of the klotho locus (kl/kl) exhibited multiple pathological conditions resembling human aging. Histomorphometric analysis revealed low-turnover osteopenia in kl/kl mice. The decrease in bone formation exceeded that of bone resorption, resulting in a net bone loss. The number of osteoblast progenitors determined by ex vivo bone marrow cultures was reduced in kl/kl mice. In addition, cultured osteoblastic cells derived from kl/kl mice showed lower alkaline phosphatase activity and matrix nodule formation than those from wild-type mice. Osteoclastogenesis in the coculture of marrow cells and osteoblastic cells was decreased only when marrow cells originated from kl/kl mice independently of the origin of osteoblastic cells. We also found that the expression of osteoprotegerin, an osteoclastogenesis inhibitor, was significantly upregulated in kl/kl mice. We conclude that a defect in the klotho gene expression causes the independent impairment of both osteoblast and osteoclast differentiation, leading to low-turnover osteopenia. Because this state represents a characteristic feature of senile osteoporosis in humans, kl/kl mice can be regarded as a useful model for investigating cellular and molecular mechanisms of age-related bone loss.

Aging↗

PubMed1999

Abnormalities of extracellular matrices and transforming growth factor beta1 localization in the kidney of the hereditary nephrotic mice (ICGN strain).

ICR-derived strain with glomerulonephritis (ICGN) is a strain of mice with hereditary nephrotic syndrome with an unidentified cause. Based on histopathological and biochemical data, ICGN mice are considered to be a good experimental model for human idiopathic nephrotic syndrome. In the present study, we histochemically investigated the changes in localization of extracellular matrix (ECM) components and transforming growth factor beta1 (TGF-beta1). Strong immunohistochemical staining of basal membrane ECM components (collagen IV and laminin) and interstitial ECM components (type III collagen and fibronectin) were demonstrated in glomeruli and tubulointerstitum of ICGN mice as compared with those of sex and age-matched ICR mice, used as normal healthy controls. Marked type I collagen and tenascin deposition, which were not detected in the glomeruli of ICR mice, were seen in the glomeruli of ICGN mice. A remarkable increase in active-TGF-beta1 was also detected only in glomeruli of ICGN mice, but not in those of ICR mice. Furthermore, strikingly increased alpha-smooth muscle actin, a marker of activated glomerular mesangial cells, was demonstrated in the glomeruli, mainly in the mesangial cells, of ICGN mice. These findings indicated that ECM components are increased in the glomerulus and tubulointerstitum of ICGN mice, and that active-TGF-beta1 induces such increases in ECM components. The present findings may contribute to elucidation of the pathogenic mechanisms of hereditary nephrotic syndrome in ICGN mice and, in future, human idiopathic nephrotic syndrome.

Animals↗

PubMed1998

A mild form of pseudoachondroplasia: minimal epi-metaphyseal involvement of long bones.

A problem in diagnosing pseudoachondroplasia (PSACH) is that the pathognomonic changes of vertebral bodies invariably disappear around the age of 10, and an adult case might subsequently be misdiagnosed as MED, Fairbank type, though the latter is less severe than PSACH. We present a Japanese girl (follow-up, 3-10 years of age) whose epi-metaphyseal involvement of long bones was minimal and whose height was +2 S.D. of standard for PSACH in spite of the typical changes of the vertebral bodies. She might not have been diagnosed only as PSACH but also as MED, Fairbank type, after disappearance of the typical vertebral body changes because of the apparent lack of stubby fingers. Since the overlap of PSACH and MED has recently been discussed from the viewpoint of molecular biology, study of the spectrum of clinical features of PSACH is important.

Achondroplasia↗

PubMed1998

Characteristics of lectin staining patterns assessed by a modified sensitive thermo-method in rat livers with heterologous serum-induced fibrosis.

Lectins are sensitive probes which bind carbohydrate structures specifically. In this study, we modified the lectin staining procedure for sensitive detection of carbohydrate structures in formalin-fixed, paraffin-embedded sections of normal and heterologous serum-induced fibrotic livers. The liver sections were heated in hot distilled water at 100 degrees C for 10 min (thermo-treatment: TT), and then stained with 24 different lectins. In comparison with the results from sections without TT (nonTT), enhanced and/or alternated staining patterns of 19 lectins were demonstrated in sections with TT, and enhanced staining of Vicia villosa agglutinin seen in Kupffer cells was noted. Interestingly, no positive staining was seen with Dolichos biflorus agglutinin, peanut agglutinin or soybean agglutinin (SBA), which recognize O-linked carbohydrate chains, in Kupffer cells of non-TT sections, but strong positive staining was demonstrated in those of TT sections. SBA-positive staining in the cytoplasm of some scattered hepatocytes located in the periportal and perifibrous zones and central zone of pseudolobules was demonstrated only in the fibrotic liver sections with TT. Such findings indicate the heterogeneity of hepatocytes in the liver with fibrosis. Formalin fixation causes masking of lectin binding sites, especially O-linked carbohydrate chains, and TT may recover such masking reactions. TT improved the staining reactions for many lectins in formalin-fixed, paraffin-embedded liver sections, and new staining patterns appear after TT. Modified TT staining procedures may be useful for the diagnosis and prognosis of liver fibrosis.

Animals↗

PubMed1998

Benign form of congenital angulation of long bones associated with shortening of soft tissues.

We report a benign form of congenital angulation of long bones associated with shortening of soft tissues. The patients were three males and four females including two siblings. The average age at first examination was 6 months (range, 1-17 months) and that at the time of follow-up was 7 years (range, 13 months-11 years). The characteristics were short-limb type short stature, congenital multiple angulation deformities of the long bones of both upper and lower extremities, with almost the same angulation directions for all the patients and improvement of the deformities with age. There was also accelerated skeletal maturation, lack of epi-metaphyseal lesions, skin dimples, limitation of the ankle joint dorsiflexion, and inconspicuousness of skin creases on the flexor side of the elbow and knee. This phenotype is not consistent with any of the bent bone dysplasia group. Caffey's report [Caffey J (1947). Am J Dis Child 74:543-5621 included two different subtypes of bent bones, round bowing and sharp angulation, and the latter are similar to this report. However, Caffey's cases lack limitation of ankle dorsiflexion and reduced skin creases. An autosomal recessive mode of inheritance could be present in this subtype.

Bone and Bones↗

PubMed1997

Involvement of Fas antigen in ovarian follicular atresia and luteolysis.

The Fas antigen (Fas) is a cell-surface receptor protein that mediates apoptosis-inducing signals and plays an important role in the immune system. Significant amounts of Fas mRNA can be detected not only in lymphoid organs but also in the liver, heart, and ovary. In the ovary, apoptosis is thought to cause follicular atresia and luteolysis. We have investigated the involvement of Fas in these events. Here we report that Fas protein is expressed on granulosa and luteal cells but not on oocytes in the ovary. An injection of anti-Fas monoclonal antibody with apoptosis-inducing activity into adult mice enhanced follicular atresia and luteolysis. After the injection, the corpora lutea disappeared and the number of follicles containing pyknotic granulosa cells increased. There were also fewer ovulated ova and lower levels of luteal cell-produced progesterone. Furthermore, as the result of a non-functional Fas/Fas ligand system, mature ovaries from the mouse mutant/pr (lymphoproliferation) were histologically abnormal in terms of follicular development, in that the number of secondary follicles significantly increased. These results suggested that Fas plays an important role in follicular atresia and luteolysis in the ovarian physiology of adult mice.

Animals↗

PubMed1997

Monoclonal antibodies against pig ovarian follicular granulosa cells induce apoptotic cell death in cultured granulosa cells.

Two monoclonal antibodies capable of inducing granulosa cell apoptosis were produced against granulosa cells prepared from antral follicles of pig ovaries. The healthy follicles, 4-5 mm in diameter, were dissected from the ovaries of gilts, and then granulosa cells were isolated. BALB/c female mice were immunized with the isolated granulosa cells. Antibodies against the granulosa cells were detected by immunofluorescent staining using frozen ovarian sections. The isolated spleen cells prepared from immunized mice producing antibodies against the granulosa cells were fused with Sp2/O-Ag 14 mouse myeloma cells by standard hybridization techniques. Two hybridoma clones, PFG-1 and PFG-2, which produced specific IgM antibodies against granulosa cells were selected. Western blotting analysis revealed that PFG-1 and PFG-2 antibodies specifically recognized cell-membrane proteins with molecular weights of 55 and 70 kD and isoelectric points of 5.9 and 5.4, respectively. The monoclonal antibodies immunohistochemically reacted with granulosa cells of healthy follicles. When the isolated granulosa cells prepared from healthy follicles were cultured in medium containing 0.1 or 10 micrograms/m/PFG-1 or PFG-2 antibodies, respectively, the cells underwent apoptosis as determined by nuclear morphology, DNA electrophoresis and flow cytometric analysis. In conclusion, these two monoclonal antibodies against granulosa cells have cell-killing activity in cultured granulosa cells.

Animals↗

PubMed1997

Lectin histochemistry in rat liver fibrosis induced by heterologous serum sensitization.

The localization of carbohydrates in rat livers with fibrosis induced by heterologous serum was examined by lectin histochemical and biochemical techniques. Twenty-four lectins were used to visualize the different carbohydrates in paraffin sections of normal and fibrotic liver tissues. No differences in staining patterns of these lectins were observed between normal and fibrotic livers in hepatocyte cell membranes including bile canaliculi, sinusoidal endothelial, or bile ductal cells. Kupffer cells strongly stained with Vicia villosa agglutinin (VVA) were seen only in the periportal zone of the normal liver, but they were observed in the periportal zone and scattered throughout the pseudolobular zone in the fibrotic liver. The cytoplasm of some hepatocytes was strongly stained by Bandeiraea simplicifolia lectin-I (BSL-I). BSL-I positive hepatocytes in normal liver were localized in the periportal zone, but those in the fibrotic liver were scattered in the periportal and perifibrous zones. After polyacrylamide gel electrophoresis of liver glycoproteins, differences in molecular sizes of BSL-I positive glycoproteins (79 and 81 kD) were detected by lectin blotting. Cell density of perifibrous BSL-I positive hepatocytes may be useful as a diagnostic parameter for liver fibrosis and/or cirrhosis. Two distinct staining patterns with twelve lectins were observed in fibrotic septa of the fibrotic liver. The fibrotic septa were stained with six characteristic lectins, and the centrilobular septa were stained with all these twelve of lectins. Histopathological assessment of the centrilobular fibrotic septa stained with these characteristic lectins may contribute to the diagnosis and prognosis of hepatic fibrosis.

Animals↗

PubMed1997

The effect of non-depolarizing neuromuscular blocking agents on the release of acetylcholine from the right atrium of the guinea pig.

The effect of various non-depolarizing neuromuscular blocking agents (gallamine, pancuronium, vecuronium, d-tubocurarine, metocurine, atracurium and pipecuronium) on [3H]acetylcholine release in the response to field electrical stimulation was investigated in vitro in preparations of the guinea pig right atrium. In this preparation, atropine enhanced and oxotremorine, a muscarinic agonist, reduced the release of [3H] acetylcholine. Atropine reversed the inhibitory effect of oxotremorine in a concentration dependent manner, indicating that there is negative feedback modulation of acetylcholine release from the vagal nerve. While pancuronium, gallamine and atracurium enhanced the release of [3H]acetylcholine, d-tubocurarine, metocurine, vecuronium and pipecuronium did not affect it. Pancuronium and gallamine also reduced the inhibitory effect of oxotremorine and the Kd value of pancuronium for muscarinic receptors located on cholinergic nerve terminals was 2.31 microM. These findings indicate that pancuronium and gallamine enhanced the release of acetylcholine from the atrial parasympathetic nerve, probably by inhibiting presynaptic muscarinic receptors.

Acetylcholine↗

PubMed1996

Apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pig ovaries.

The porcine antral follicles, 3-6 mm in diameter, were dissected from the ovaries of mature pigs, and then granulosa and cumulus cells were isolated from each follicle. In atretic follicles, high activity of neutral Ca2+/Mg2+-dependent endonuclease and DNA ladder formation, estimated by electrophoresis, were noted in granulosa cells but not in cumulus cells. Extremely low activity of the endonuclease and no DNA ladder formation were observed in both types of cells obtained from healthy follicles. Moreover, apoptotic cells were observed histochemically among granulosa cells only. A good correlation (r = 0.987) between the endonuclease activity of granulosa cells and the progesterone/estradiol ratio of follicular fluid in each follicle was found. These results suggest that apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pigs.

Animals↗

PubMed1996

Effects of the mycelial extract of cultured Cordyceps sinensis on in vivo hepatic energy metabolism in the mouse.

Mice were given the extract of cultured Cordyceps sinensis (Cs) (200 mg/kg daily, p.o.) for 3 weeks. In vivo phosphorus-31 nuclear magnetic resonance (NMR) spectra of the liver were acquired at weekly intervals using a surface coil. From 1 to 3 weeks, a consistent increase in the ATP/inorganic phosphate ratio, which represents the high energy state, was observed in the Cs extract-treated mice. The intracellular pH of the Cs extract-treated mice was not significantly different from that of the control mice. No steatosis, necrosis, inflammation or fibrosis were observed in the liver specimens from Cs extract-treated mice.

Adenosine Triphosphate↗

PubMed1995

Female reproductive properties and prenatal development of a senescence-accelerated mouse strain.

Female reproductive properties, early embryonic development, and serum estradiol and progesterone levels of the senescence-accelerated mouse (SAM)-prone (SAM-P) strain were compared with those of a SAM-resistant (SAM-R) strain. The reproductive life span of SAM-P (from 11.4 to 25.0 weeks old) was shorter than that of SAM-R (11.1 to 41.6 weeks old), and the total number of SAM-P pups was 41.7% less than from SAM-R. The reproductive senescence of SAM-P is more accelerated than that of SAM-R. At 15 weeks old, the maximum litter size of SAM-P was noted and was 33.7% smaller than that of SAM-R. Although no differences in the numbers of ovulated and fertilized ova were observed between two strains, the number of implants in SAM-P was 21.6% less than in SAM-R. Cell cleavage was delayed in embryos of SAM-P (8% morula, at day 2 of pregnancy) compared to SAM-R (48%). At day 3 of pregnancy, 9% and 33% of the embryos were blastocysts in SAM-P and SAM-R, respectively. At day 1 of pregnancy, serum estradiol level in SAM-P was 18.2% higher than in SAM-R, whereas the serum progesterone level in SAM-P was 46.2% lower than in SAM-R. The unbalance of estradiol and progesterone levels in SAM-P was considered to be the cause of the delay in early embryonic development, and then the decrease of implantation and a smaller litter size.

Aging↗

PubMed1995

A sporadic case of Ehlers-Danlos syndrome type IV: diagnosed by a morphometric study of collagen content.

A sporadic case of a young woman with Ehlers-Danlos syndrome (EDS) type IV is described. Multiple aneurysms of medium-sized arteries were noted. Histological study revealed deposition of acid mucopolysaccharides in the media of major arteries and in the intima of smaller arteries with intimal thickening. Systemic changes related to stenosis were observed in arteries more than 100 microns in diameter. Histologic study revealed hyperplasia of adipocytes in the submucosal layer of the intestines and the trachea, and fibrosis of Langerhans' islets of the pancreas. Typical signs for EDS such as skin hyperelasticity and joint hypermobility, and positive family history were not present. However, type III collagen was not detected on frozen sections from either the skin or the anterior cerebral artery by immunohistochemical quantification. Thus, it was concluded that the present case is a variant of EDS.

Adolescent↗

PubMed1995

Immunohistochemical quantitation for extracellular matrix proteins in rats with glomerulonephritis induced by monoclonal anti-Thy-1.1 antibody.

Extracellular matrix proteins (type I collagen and fibronectin) in frozen histologic sections of kidney cortex from rats with glomerulonephritis induced by a single intravenous administration of anti-Thy 1.1 antibody were quantified using an immunohistochemical micromethod. Type I collagen and fibronectin contents in renal cortex of rats with experimental glomerulonephritis (4.33 +/- 0.79 and 10.41 +/- 2.01 microgram/mg of total protein, respectively) were 262% and 151%, respectively, higher than in control rats given normal mouse IgG (1.65 +/- 0.16 and 6.88 +/- 0.95 microgram/mg, respectively; p < 0.01 in each case). In the glomerulonephritic rats, the increase in the contents of extracellular matrix proteins, especially type I collagen, correlated with increasing glomeruli with expansion of mesangial areas. The increase in type I collagen content correlated well with increasing urinary protein excretion and blood urea nitrogen and serum total cholesterol levels (r = 0.851, 0.812, and 0.837, respectively; p < 0.05 in each case). The decrease in creatinine clearance correlated with increasing content of type I collagen (r = 0.781; p < 0.05). The immunohistochemical micromethod may make it possible to evaluate the histopathological diagnosis of mesangial proliferative glomerulonephritis quantitatively.

Animals↗

PubMed1995

Renal responses to atrial natriuretic peptide (ANP) in rats with non-oliguric acute renal failure induced by cisplatin.

This study was designed to compare the renal effects of atrial (A-type) natriuretic peptide (ANP) on control (saline-injected) rats and rats with non-oliguric acute renal failure induced by cisplatin. The results obtained here are summarized as follows: (1) In the metabolic cage study, cisplatin-treated rats showed increases in blood urea nitrogen and serum creatinine while creatinine clearance decreased to the lowest levels on day 4. A transient increase in urinary protein was observed at day 4. (2) ANP infusion significantly increased urine flow rate (UFR), creatinine clearance (CCr), fractional excretion rates of sodium (FENa) and chloride (FECl), and urinary phosphorus and magnesium (Mg) excretions in a dose-dependent manner without affecting renal plasma flow and fractional excretion rates of potassium and urea in cisplatin-treated rats. (3) Renal effects of ANP on UFR, CCr, FENa, FECl and excretion of Mg were more pronounced in cisplatin-treated rats compared to control rats although markedly blunted responses to ANP have been reported in nephrotic patients and nephrotic animals induced by adriamycin and aminonucleoside. (4) Histological examination showed extensive necrosis of the S3 segment of the proximal tubule located in the outer stripe of the outer medulla with minimal glomerular abnormalities in the kidney of cisplatin-treated rats. In conclusion, the main mechanism of the increased renal responses to ANP is considered to be due to an increased delivery of sodium, fluid and ANP itself to the inner medullary collecting duct which is the major renal site of action of ANP under the condition of acute proximal tubular necrosis by cisplatin.

Acute Kidney Injury↗

PubMed1995

Immunohistochemical microquantification of fast-myosin in frozen histological sections of mammalian skeletal muscles.

Fast-myosin in frozen histological sections was quantified by an immunohistochemical micromethod based on the ELISA. Frozen tissue sections mounted on glass slides were used analogously to the antigen-precoated wells of ELISA plates. The intensity of immunoreactivity of frozen sections to an anti-fast-myosin monoclonal antibody was quantified directly from the color developed with the second antibody coupled with peroxidase using phenol-4-aminoantipyrine as a substrate. Fast-myosin levels in the masseter muscles of pigs, rats, and rabbits were 185 +/- 6, 223 +/- 9, and 178 +/- 12 mg/g of total protein, respectively, and those in the gastrocnemius muscles from cows, pigs, goats, rats, and rabbits were 172 +/- 12, 211 +/- 7, 177 +/- 9, 211 +/- 10, and 205 +/- 10 mg/g, respectively. In the masseter of cows and goats, fast-myosin was not detected. The results obtained by this immunohistochemical micromethod were in good agreement with those obtained by histomorphometrical and biochemical analyses. This immunohistochemical micromethod could be used to quantitatively evaluate the muscle contractile characteristics that determine meat quality.

Animals↗

PubMed1994

A morphometric study of spermatogenesis in the testes of mice of a senescence accelerated strain.

The morphometric parameters of spermatogenic cells in a mouse strain prone to accelerated senescence (SAM-P), a novel murine model of spontaneously promoted aging, were compared with those of a SAM resistant strain (SAM-R) after birth until 40 weeks (mean life span of SAM-P). A mixture of gonocytes and spermatogonia were present in the testis in 1-week-old mice, and no gonocytes were observed in 2-week-old mice. At 6 weeks of age, the absolute number of spermatogonia in SAM-P was 27% greater than that in SAM-R, whereas the cell number in 40-week-old SAM-P was 17% less than in SAM-R. Primary spermatocytes were first observed in 3-week-old animals, and the cell numbers in SAM-P at 3, 5 and 6 weeks were 78%, 31% and 25%, respectively, greater than in SAM-R, whereas the cell number in SAM-P at 40 weeks was 30% less than SAM-R. Round spermatids were first observed in all SAM-P at 4 weeks old, but 20% of SAM-R had no spermatids and the rest had only a few. At 5 and 6 weeks old, the absolute numbers of round spermatids in SAM-P were 38% and 41%, respectively, greater than in SAM-R, whereas the cell number in 40-week-old SAM-P was about 34% less than SAM-R. These results indicate that testicular maturation begins at an earlier age in SAM-P than SAM-R. Furthermore, at the age of 40 weeks signs of testicular deterioration are evident in SAM-P mice only.

Aging↗

PubMed1994

Immunohistochemical microquantitation method for type I collagen in kidney histological section of the rats.

An immunohistochemical micromethod for quantitation of type I collagen in frozen histological section of rat kidney was developed. A principle of this method is enzyme-linked immunosorbent assay (ELISA). The intensity of immunoreactivity of the section to an anti-type I collagen antibody was quantitated, and then the total protein content in the same section was measured colorimetrically. Type I collagen content was expressed as mg of type I collagen per g of total protein. In this micromethod, the minimum area and optimum thickness of the section were 5 mm2 and 10 microns, respectively. Type I collagen content in the rat kidney section was 3.02 +/- 0.12 mg/g. This method should be useful for diagnosis of renal failure.

Animals↗