Distribution of adrenomedullin-containing perivascular nerves in the rat mesenteric artery

Distribution of adrenomedullin (AM)-containing perivascular nerve fibers was studied in rat mesenteric arteries. Many fibers containing AM-like immunoreactivity (LI) were observed in the adventitia. AM-LI fibers were abolished by cold storage denervation or capsaicin but not 6-hydroxydopamine. Double immunostainings showed colocalization of AM-LI with calcitonin gene-related peptide (CGRP)-LI. The dorsal root ganglia had many AM-positive cells and AM mRNA detected by RT-PCR. Electron microscopy study revealed high proportions of immunogold labeling for AM and colocalization of both AM-LI and CGRP-LI in unmyelinated nerve axons. These results suggest that AM-containing perivascular nerves are distributed in the rat mesenteric artery.

Resorption of the postero-superior corner of the lateral part of the mandibular condyle correlates with progressive TMJ internal derangement

The purpose of this study was to test the hypothesis that resorption of postero-superior corner of lateral part of the mandibular condyle (RLC) occurs with the advancement of TMJ internal derangement (ID). One hundred and sixty-seven TMJs in 122 patients were studied. RLC was assessed on plane radiographs of frontal oblique projection. The correlation between the prevalence of RLC and radiological stage of ID was analysed and clinical correlations to the radiological stage of ID and the prevalence of RLC were discussed. The higher prevalence of RLC in joints with advanced ID was statistically significant (Mann-Whitney U-test, P< 0.05). There was no correlation between the prevalence of RLC and neither OA on the articular surface of the condyle nor clinical symptoms/signs. The result of this study suggests that RLC appears to occur in joints with advanced ID as a result of remodelling changes secondary to ID.

Tea polyphenols reduce glucocorticoid-induced growth inhibition and oxidative stress in broiler chickens

1. The effects of dietary polyphenols (PP) on growth and oxidative stress in the corticosterone (CTC) treated broiler chickens model were studied. 2. Chicks (Cobb strain) were divided into 3 (CTC) x 3 (PP) blocks and given diets containing CTC at concentrations of 0, 10 and 20 mg/kg. 3. The body weight gain was lower when the birds were treated with CTC. However, the high dose of PP tended to reduce the effect of CTC. 4. The abdominal fat content, plasma triglyceride concentration and liver weight were increased by CTC and reduced by PP. 5. Muscle and liver thiobarbituric acid reactive substance (TBARS) were elevated by CTC and these effects were reduced by PP. Plasma CTC concentration was increased by dietary CTC treatment and decreased by PP. 6. In conclusion, our results indicate that PP can minimise growth inhibition, hyperlipidemia and oxidative stress induced by CTC treatment in broiler chickens.

Effects of corticosterone on Ca2+ uptake and myofibrillar disassembly in primary muscle cell culture

This study was done to examine the effects of corticosterone, a glucocorticoid, on Ca2+ uptake, proteolysis, and Ca2+ channels in primary cultures of chick muscle cells, to clarify the mechanism of glucocorticoid action on muscle proteolysis. Chick muscle cells were incubated for 24 h in a medium containing corticosterone (30 ng/ml) when the cells were confluent (6 days). To examine the contribution of Ca2+ channels, nifedipine, a Ca2+ channels antagonist, was used. Ca2+ uptake measured with 45CaCl2 was increased three-fold by corticosterone, with a peak at 12 h after the treatment started. The growth of the cells estimated from the protein content and creatine kinase activity was not affected by corticosterone. Proteolysis, evaluated with [3H]tyrosine as a label of the protein and Ntau-methylhistidine release, was unchanged by corticosterone. However, the amount of easily releasable myofilament as a measure of myofibrillar disassembly in the muscle cells was increased by corticosterone, and prevented by nifedipine. These results show that corticosterone increases Ca2+ uptake and starts myofibrillar protein breakdown.

Relationship between increased horizontal condylar angle and resorption of the posterosuperior region of the lateral pole of the mandibular condyle in temporomandibular joint internal derangement

OBJECTIVES

The purpose of this study was to analyse the relationship between horizontal condylar angle, temporomandibular joint (TMJ) disk displacement and resorption of the lateral pole of the mandibular condyle (RLC).

METHODS

The study comprised 162 TMJs (81 patients). Disk displacement was assessed and the horizontal angle of the condyle was measured on axial MR images. RLC was assessed on oblique frontal projection plain radiographs.

RESULTS

The horizontal angle was increased in joints with disk displacement without reduction (one-factor ANOVA and Scheffe's f-test, P<0.05). The angle was greater in joints with RLC than in the joints without RLC (Student's t-test, P<0.05).

CONCLUSIONS

Results suggest that the horizontal condylar angle is increased in joints with disk displacement without reduction. A possible relationship exists between RLC and increased horizontal condylar angle.

Alteration of the horizontal mandibular condyle size associated with temporomandibular joint internal derangement in adult females

OBJECTIVES

The purpose of this retrospective study was to analyse the relationship between horizontal size of the mandibular condyle and internal derangement (ID) of the temporomandibular joint (TMJ).

METHODS

One hundred and thirty-nine joints in 88 women aged over 18 years were included in this study. The horizontal condylar size was measured in the antero-posterior and medio-lateral (ML) dimensions using axial magnetic resonance (MR) images. Radiological findings of ID were also assessed from MR imaging.

RESULTS

The condyles in the joints with permanent disk displacement were smaller than those in joints without displacement in both dimensions (Fisher's protected least significant difference, P<0.05). There were statistically significant correlations between horizontal condylar size in the ML dimension and both disk morphology and radiological stage of ID (Spearman's correlation coefficient by rank, P<0.05).

CONCLUSIONS

The results of this study suggest a possible relationship between horizontal condylar size and disk displacement. It is also suggested that the condyle becomes smaller in the ML dimension with advancement of ID.

Effects of the thyroid hormone on differentiation, growth, and proteolysis in cultured muscle cells during serum deprivation

The actions of the thyroid hormone (T3) are modified by other hormones. Therefore, in the normal cell culture system, with serum as a medium ingredient, it is difficult to eliminate the influences of other hormones derived from the serum. In the present study, two experiments were conducted to clarify the effects of T3 on differentiation, growth and proteolysis (experiment 1), and concerted effects of T3 and insulin (experiment 2) in a serum-free culture with the use of muscle cells originated from chick embryo. Protein content and creatine kinase (CK) activity were examined as indices of growth and differentiation of the muscle cells, respectively, and N(tau)-methylhistidine (MeHis) release was examined as an index of myofibrillar proteolysis. It was observed that T3 suppressed both the muscle differentiation and proteolysis in the serum-free medium (experiment 1), though in our previous experiment they were enhanced by T3 in the serum-supplemented normal medium. On the other hand, T3 increased myofibrillar proteolysis and had no effect on muscle differentiation when insulin was included in the serum-free medium (experiment 2). These results clearly show that the effects of thyroid hormones on muscle differentiation and proteolysis are apparently different when serum is deprived from the medium, and these differential effects of thyroid hormone could be partially explained by an interaction with insulin, one of the growth factors in the serum.

Repulsive charge mechanism serve to maintain lumens and cavities. An histochemical study of rat serosa and kidney

The free surface of the rat peritoneum was covered with a rich negative-charged substance which is distinctly stained with cationic colloidal iron (pH 1.5). Neuraminidase digestion erased this iron stain. Treatment with Limax flavus agglutinin (LFA), which has specific affinity to sialic acid, interferred with iron staining on the serosal surface. Transmission electron microscopy of the peritoneal samples stained with colloidal iron showed that colloidal particles were deposited on the free surface of the mesothelial cells. At pH 1.5, the colloidal particles aggregated in a dotted fashion; in those stained at pH 7.0, the particles arranged in fine strands (100-300 nm in length). This difference may occur as a structural transformation due to pH level changes. The string like structure seemed to correspond well to membrane associated sialomucin. The urinary surface of the rat glomerular podocytes possessed negatively charged sites detectable with cationic colloidal iron even at pH 1.5. Neuraminidase and LFA treatments erased iron staining. Substance containing sialic acid such as podocalyxin on the podocyte surface may be stained. This study shows that negatively charged sites of the substance covering the free surface of these regions repulse each other to maintain the serosal cavities or the podocyte end-feet slits.

The extracellular matrix in the mature brain: its reactions to endo-alpha-N-acetylgalactosaminidase and collagenase

The hippocampal subiculum in the adult rat brain contains many neurons with nerve cell surface glycoproteins which are linked by collagenous ligands to perineuronal proteoglycans. The nerve cell surface glycoproteins or their terminal N-acetylgalactosamines are digested by endo-alpha-N-acetylgalactosaminidase. The terminal N-acetylgalactosamines linked by the collagenous ligands are not digested by endo-alpha-N-acetylgalactosasminidase. The collagenous ligands associated with the terminal N-acetylgalactosamines were digested by collagenase. The newly exposed terminal N-acetylgalactosamines by this collagenase incubation were digested by endo-alpha-N-acetyl-galactosaminidase. These findings on the rat agree with those obtained in our previous studies of the adult mouse brain samples. Furthermore they emphasize our hypothetical model that the perineuronal proteoglycans are related--via collagen ligands--with the nerve cell surface glycoproteins.

Ectopic osteogenesis with biphasic ceramics of hydroxyapatite and tricalcium phosphate in rabbits

Porous calcium phosphate ceramics consisting of hydroxyapatite (HA) and tricalcium phosphate (TCP) with different HA to TCP ratio were implanted intramuscularly in rabbits for six months in order to carry out a comparative study on osteogenic activity of the ceramics. Bone formation was detected only in HT73 (HA to TCP ratio, 7-3) specimens. Other implants, HT28 (2-8) and HT010 (0-10), could not induce bone. After a six-month period of implantation, HT28 and HT010 implants showed obvious degradation of the implants changing their shape and size macro and microscopically. Microscopically, they showed aggregates of fine particles and appearance of multinucleated cells. However, HT73 implants was less degraded and could maintain their original structure macro and microscopically. This study showed that HT73 ceramics can induce bone in rabbit muscle tissue and it is considered that maintenance of porous structure, that is, degradation rate of the materials may be one of the affecting factors in ceramic-induced osteogenesis.

Chondroitin sulfate proteoglycan at the basal lamina beneath high endothelial cells in human palatine tonsils: a light and electron microscopic study using the cationic colloidal iron method

The basal lamina of high endothelial venules (HEVs) in human palatine tonsils was intensely stained with cationic colloidal iron at pH 1.5 and with aldehyde fuchsin. This basal lamina exhibited a thick and double- or triple-layered structure forming small compartments, in which many lymphocytes were aligned. Digestion with hyaluronidase or collagenase eliminated both the colloidal iron and aldehyde fuchsin stainings of the basal lamina of HEVs. Treatment with chondroitinase ABC reduced colloidal iron staining, but did not interfere with the aldehyde fuchsin staining. Digestion with neuraminidase, keratanase, or heparitinase did not eliminate either the cationic colloidal or the aldehyde fuchsin staining. Digestion with neuraminidase reduced the colloidal iron staining on the luminal surface coat of the HEV. Electron microscopy of ultrathin sections revealed that cationic colloidal iron particles were deposited on the basal lamina of the HEV. The basal laminae of ordinary blood vessels were thin and single-layered, and stained only weakly with cationic colloidal iron. The present study suggests that negatively charged sites in the basal lamina of HEV derive mainly from a proteoglycan complex containing hyaluronic acid and chondroitin sulfate, which firmly binds collagen. This topochemical feature is suggested to be involved in the fascilitating migration of lymphocytes after passage through the endothelial layer.

Biliary tract of the rat as observed by scanning electron microscopy of cast samples

The three-dimensional distribution of the biliary tract in the rat was studied by scanning electron microscopy of biliary casts. The casts were prepared by a retrograde infusion of a low viscosity or monomeric methacrylate resin mixture into the common bile duct. No resin flow from the bile canaliculi to sinusoidal capillaries was ever noted. Bile canaliculi formed intricate meshworks and drained via the Hering's canals into the bile ductules. The bile canalicular meshworks of adjacent lobules intercommunicated with each other. The bile ductules formed a marked periportal plexus around the portal vein branch, and drained into the intrahepatic bile duct running along the portal vein branch. The junctional zone of the Hering's canal and bile ductule usually showed an ampullary dilation. When the Hering's canal directly drained into a thick bile ductule or into a periportal plexus of bile ductules, such an ampullary dilation at the origin of the bile ductule was never replicated. The extrahepatic bile duct protruded many crypt-like projections which presumably corresponded to parietal glands. It is suggested that the periportal plexus of bile ductules may store the bile as a substitute for the gallbladder.

The intensely positively charged perineuronal net in the adult rat brain, with special reference to its reactions to oxine, chondroitinase ABC, hyaluronidase and collagenase

Light microscopic observations of healthy adult rat brain sections stained with anionic iron colloid indicated that 5-10% of neurons in the hippocampal subiculum and all neurons in the medial cerebellar nucleus possessed an intensely positively charged perineuronal net. This net was demonstrated to react to oxine, and therefore suggested to consist of guanidino compounds. It was further shown that the intensely positively charged perineuronal net, in accordance with the intensely negatively charged perineuronal net of proteoglycans, was digested by chondroitinase ABC, hyaluronidase, and collagenase, but not by endo-alphaN-acetylgalactosaminidase. This finding suggested that the former positively charged net might be linked to the latter negatively charged one.

A study of factors for successful splint capture of anteriorly displaced temporomandibular joint disc with disc repositioning appliance

The purpose of this study was to analyse the factors which influenced the success of disc recapture by the insertion of a disc repositioning appliance. Fifty-one joints with joint clicking that occurred at both middle to late opening and late closing (near maximum cuspation) of the mandible were splinted with a mandibular full-coverage repositioning appliance. The clinical and MR findings were compared between the joints with successful and unsuccessful splint disc capture. Thirty-two clicking joints with reducibly displaced discs (DDWR) had successful disc recapture, while six of 19 joints with displaced disc without reduction (DDWOR). Unsuccessful joints with DDWOR had significantly higher prevalence of deformed disc and joint effusion, higher VAS quantitative pain score, and severe disc displacement especially in medial part of the joint (P < 0.05). From the results of this study joints with DDWR can be expected to have successful disc recapture with the insertion of the appliance. In joints with DDWOR, presence of inflammatory conditions, changed disc morphology and extensive disc displacement in medial part of the joint are negative factors.

Purkinje cells in the adult cat cerebellar cortex possess a perineuronal net of proteoglycans

The Purkinje cells in the adult cat cerebellar cortex were found to possess perineuronal proteoglycans which could be stained with our fine cationic iron colloid and Fujita's highly concentrated aldehyde fuchsin, and digested by chondroitinase ABC/keratanase/ heparitinase and hyaluronidase. The Purkinje cells are surrounded by some collagenous elements which are stained with Gömöri's ammoniacal silver and digested by collagenase. The Purkinje cells also express nerve cell surface glycoproteins which are labeled with lectin Vicia villosa agglutinin and digested by a double treatment with collagenase and endo-alpha-N-acetylgalactosaminidase. Sole digestion by endo-alpha-N-acetylgalactosaminidase never erased the lectin labeling of the nerve cell surface glycoproteins. These findings suggest that the collagenous elements mediate the linkage of the perineuronal proteoglycans to the nerve cell surface glycoproteins. It is presumed that in mice and rats, the perineuronal nets of proteoglycans and nerve cell surface glycoproteins of the Purkinje cells are so thin or coarse that they can not be sufficiently visualized under the light microscope.

Chewing ability as a parameter for evaluating the disability of patients with temporomandibular disorders

Restoration of chewing ability is an important aspect of the treatment for temporomandibular disorders (TMDs). However, too little attention has been paid to it. We have used a questionnaire to evaluate and score the chewing ability of TMD patients. The questionnaire includes 19 kinds of food and a chewing task. The patient was asked if she/he experiences difficulty in enjoying eating. The aim of this study was to evaluate correlations between score of chewing ability (SCA) and other symptoms/signs of TMD. Four hundred and seventy-three consecutive TMD patients were evaluated for SCA and other symptoms/signs including temporomandibular joint (TMJ) pain, TMJ and muscle tenderness, TMJ noise (clicking and crepitus), and maximum mouth opening. The relationship between SCA and other symptoms/signs were analysed by multiple regression analysis. Score of chewing ability correlated significantly with TMJ pain and mouth opening capacity but not with TMJ noise and muscle tenderness. Age was a background factor but sex was not. The result of this study suggests that SCA correlated with dysfunction of the TMD patients. This method could be used to evaluate the ability of chewing in assessment of TMD.

A study of the relationship between the position of the condylar head and displacement of the temporomandibular joint disk

OBJECTIVES

To examine the possible relationship between condylar position and disk displacement in the TMJ.

METHODS

Forty-eight joints with no disk displacement (NDD), 84 joints with a reducible displaced disk (RDD) and 99 joints with a permanently displaced disk (PDD) were selected. The positions of the condyle and TMJ disk were calculated from lateral MR images.

RESULTS

There were significant differences in condylar position between the joints with NDD and RDD, while there was no difference between those with NDD and PDD (Kruskal-Wallis and post-hoc test, P<0.05). There was also a significant correlation between the position of the condylar and the displaced disk (Spearman's rank correlation, P<0.05). The condyle was located more anteriorly with advancing disk displacement.

CONCLUSIONS

We suggest that if the disk displacement is slight, the condyle is displaced posteriorly: as the disk displacement becomes more severe (i.e. more anteriorly displaced), the condyle returns to the concentric position.

Intensely negative-charged pericapillary spaces in the rat pineal gland

Electron microscopy of ultrathin sections stained with cationic iron colloid revealed that the rat pineal gland is provided with wide and intensely negative-charged pericapillary spaces. Light microscopically, the negative charging of the pericapillary spaces was completely eliminated by digestion with hyaluronidase and chondroitinase ABC. This pericapillary negative charging was also erased by digestion with collagenase. The results indicate that the negative charging is derived from sulfated proteoglycans which are bound to collagen molecules. These sulfated proteoglycans in the pericapillary spaces may retain numerous water molecules to form a tissue gel, and so act as a selective sieve regulating the passage of tissue molecules.

Enhanced visualization of weak colloidal iron signals with Bodian's protein silver for demonstration of perineuronal nets of proteoglycans in the central nervous system

The present study aimed for a clear visualization of faintly deposited colloidal iron in tissue sections for light microscopy. Paraffin blocks containing paraformaldehyde-fixed brain tissue from healthy adult mice were cut into sections 10-15 microm thick. After deparaffinization, the sections were stained with fine cationic iron colloid at a pH value of 1.0-1.5, and treated with a mixture of potassium ferrocyanide and hydrochloride for Prussian blue reaction. Some sections were further treated with Bodian's protein silver after the Prussian blue reaction. This sensitized development of Prussian blue reaction with Bodian's protein silver more clearly visualized the faintly deposited cationic colloidal irons than the demonstration by Prussian blue reaction alone, and allowed an enhanced visualization of the perineuronal nets of sulfated proteoglycans in the brain. Thus, such fine perineuronal sulfated proteoglycans as those in the CA3 field of the hippocampus, which are weakly stained with cationic iron colloid and usually overlooked by a demonstration with only a Prussian blue reaction, could be clearly visualized with striking contrast by the sensitized development with Bodian's protein silver after the Prussian blue reaction. Preliminary hyaluronidase digestion erased Bodian's protein silver development of perineuronal sulfated proteoglycans. Though some axonal fibers were also additionally stained with Bodian's protein silver itself, this sensitized development is useful to enhance such weak colloidal iron signals as are hardly detectable by only Prussian blue reaction.

Resorption of the lateral pole of the mandibular condyle in temporomandibular disc displacement

OBJECTIVES

To assess the possible relationship between resorption of the superolateral pole of the mandible condyle (RSLC) and TMJ disk displacement.

METHODS

Two hundred and seventeen TMJs in 138 patients were studied. Displacement of the disc, degree of displacement and disc configuration were assessed using MRI. RSLC was assessed from a transorbital radiograph.

RESULTS

Seventy-two joints (37%) were considered to have RSLC. A significantly higher prevalence of RSLC was found in joints with disc displacement (goodness test of fit for chi-square, P<0.05). A significantly higher prevalence of RSLC was found in joints with advanced disc displacement and advanced disk deformation (Mann-Whitney U-test, P<0.01).

CONCLUSIONS

RSLC appears more likely to occur in joints with advanced disc displacement.

Intensely positively charged perineuronal nets in the adult rat brain as detected by staining with anionic iron colloid

Ferric chloride, when boiled with ammonium thiocyanate, ammonia and cacodylic acid, is converted into a fine anionic iron colloid which consists of 1.0-1.5 nm electron dense granules and gives a distinct Prussian blue reaction (OHTSUKA and MURAKAMI, 1986). Light microscopy of tissue sections stained with this fine anionic iron colloid at pH values of 6.0, 7.0 and 8.0 showed that the healthy adult rat brain contains a considerable number of neurons which possess an intensely positively charged perineuronal net. This net was most clearly demonstrable by staining with the anionic iron colloid at a pH value of 8.0, at which ionizations of almost all cationic sites of the tissue elements were obliterated. Transmission electron microscopy of ultrathin sections stained at a pH value of 8.0 showed that the anionic iron colloid was preferentially deposited in the perineuronal tissue spaces. These findings indicate that the intensely positively charged perineuronal net contains some strongly basic substances such as guanidino compounds, and occupies the perineuronal (perisynaptic) tissue space.

A High Dose of Vitamin E Inhibits Adrenal Corticosterone Synthesis in Chickens Treated with ACTH

The present experiment was conducted to study the effects of dietary vitamin E on plasma corticosterone (CTC) concentration and adrenal steroid syntheses in chickens treated with adrenocorticotropic hormone (ACTH). Chickens were divided into ACTH(-) and ACTH(+) groups, and each group was further divided into three subgroups administered with vitamin E (500 or 5,000 mg/kg diet) and without the vitamin. Vitamin E (DL-alpha-tocopheryl acetate) was mixed with the basal diet at levels of 500 and 5,000 mg/kg and fed for 6 d. ACTH (20 IU/kg body weight) was given daily by intraperitoneal injection for 5 d. alpha-Tocopherol levels in the plasma and adrenal gland were markedly elevated by vitamin E feeding, and the level of adrenal free cholesterol (CHOL), which is used for steroid synthesis, was significantly decreased by vitamin E feeding in a dose-dependent manner. However, the level of adrenal CHOL ester was unchanged by any treatment. The elevations of pregnenolone, progesterone and CTC levels in the adrenal gland of chickens with ACTH treatment were decreased by vitamin E administration. The elevation of plasma CTC concentration in the ACTH(+) group was dramatically decreased by vitamin E administration, while that concentration was not influenced by the vitamin administration in the ACTH(-) group. These findings indicate that vitamin E suppresses the elevation of the plasma CTC concentration due to ACTH in chickens, possibly by inhibiting the conversion of CHOL ester to free CHOL in the adrenal gland.

Effects of corticosterone on connectin content and protein breakdown in rat skeletal muscle

We examined the effects of a glucocorticoid, corticosterone, on calpain activity, connectin content and protein breakdown in rat muscle. The results indicated that calpain activity was increased by corticosterone and thus breakdown of connectin was stimulated followed by increased breakdown of skeletal muscle protein.