[The PCNA immunohistochemical study of pterygium]

OBJECTIVE

To study the proliferating status of pterygium and the drug's influence on it.

METHOD

Fifty four patients with pterygium were randomly assigned into three groups: Before the surgical excision of the pterygium, group 1 (18 cases) had received no drug, group 2 (16 cases) received local dexamethasone treatment, and group 3 (20 cases), local homoharringtonine and dexamethasone treatment. The immunohistochemical study on proliferating cell nuclear antigen (PCNA) was performed on the surgical specimens of the pterygium.

RESULT

The PCNA positive rate was (11.53 +/- 3.62)% in the untreated group, (10.28 +/- 4.18)% in the dexamethasone group (P > 0.05), and (5.59 +/- 3.82)% in the homoharringtonine and dexamethasone group (P < 0.01). The PCNA positive rate was higher in the younger patients (< 60 years) with progressive type of the disease than that in the elder patients (>or= 60 years) with quiet type.

CONCLUSIONS

There are cell proliferation and PCNA expression in pterygium. The homoharringtonine and dexamethasone local injection before the excision of pterygium can effectively decrease the PCNA expression and recurrence rate of pterygium. Local injection of dexamethasone before surgical excision has no influence on the PCNA expression of pterygium.

Myocardial retinoid X receptor, thyroid hormone receptor, and myosin heavy chain gene expression in the rat during adult aging

Although previous studies have shown that cardiac myosin heavy chain (MHC) composition undergoes a switch from the alpha- to beta-isoform in the heart during adult aging, the underlying mechanisms responsible for this switch are unknown. Cardiac MHC gene expression is regulated, in part, by thyroid hormone responsive elements present in the regulatory control regions of the alpha- and beta-MHC genes. Age-associated changes in the expression of thyroid hormone receptors (THRs) and/or retinoid X receptors (RXRs), the heterodimeric partner for THRs, could explain the age-associated changes in MHC expression. Accordingly, we measured mRNA levels for the cardiac muscle MHCs and the rat THR and RXR genes in the left ventricles of Wistar rats at 2, 6, and 24 months of age. Although there were no significant changes in RXR alpha or RXR beta mRNA levels with age, both alpha 1 and alpha 2 THR mRNA levels decreased significantly between 2 and 6 months of age. During this same time period, the mRNA levels for alpha-MHC declined by more than half, whereas beta-MHC mRNA levels remained low and unchanged. On the other hand, between 6 and 24 months, when mRNA levels for beta-MHC increased and alpha-MHC continued to decrease, there was a significant decline in THR beta 1 and RXR gamma mRNA levels accompanied by a reduction in the THR beta 1 and RXR gamma protein levels. These data show a pattern of change that suggests that the decline in alpha-MHC gene expression may be biphasic and due to a decline in alpha 1 (and possibly alpha 2) THR levels between 2 and 6 months of age and a decline in THR beta 1 and RXR gamma levels at later stages. In contrast, the increase in beta-MHC gene expression was associated only with the changes in THR beta 1 and RXR gamma mRNA and protein levels.

[Evaluation in the relationship of disc displacement of temporomandibular joint to osteoarthrosis in the rabbit]

OBJECTIVE

The purpose of this study, using an animal model, was to evaluate the relationship between disc displacement of temporomandibular joint (TMJ) and osteoarthrosis.

METHODS

The disc was surgically displaced anteriorly in the right TMJ in each of 25 rabbits. The TMJs were removed after 1, 2, 4, 8, and 12 weeks and stained with H&E.

RESULTS

11 joints had partial anterior disc displacement, 8 joints with complete anterior disc displacement and 6 joints with perforation. The partial anterior disc displacement joints showed early degenerative or physiologic remodeling changes, the complete anterior disc displacement and perforation joints showed degenerative or severe osteoarthritic changes.

CONCLUSION

The degree of anterior disc displacement of TMJ relates to the osteoarthrosis. The farther anteriorly, the more easily disc displacement can cause the osteoarthrosis.

[A study on the clinical curative effect by acupuncture for myofascial pain dysfunction syndrome]

OBJECTIVE

To study the acupuncture treatment for myofascial pain dysfunction (MPD) using infrared thermography and microcirculation.

METHODS

The temperature of the skin on the TMJ regions, the blood vessels and the blood flow of the Nail Fold capillary loops, were observed in the group of the acupuncture He Gu and Min Yin point and the control group.

RESULTS

There were high temperature of the skin on the TMJ regions, and enlarged blood vessels and increased blood flow of the Nail Fold capillary loops in the treatment group, with elimination of, pain and increase of mouth opening as compared with the control group. The effective rate of the acupuncture treatment of 477 cases of MPD is 93.1%.

CONCLUSION

The He Gu and Min Yin points are sensitive point for the treatment of MPD.

Enhanced expression of p53 and apoptosis induced by blockade of the vacuolar proton ATPase in cardiomyocytes

Activation of the vacuolar proton ATPase (VPATPase) has been implicated in the prevention of apoptosis in neutrophils and adult cardiac myocytes. To determine the role of the VPATPase in apoptosis of cardiac myocytes, we used a potent and specific inhibitor of the VPATPase, bafilomycin A1. Bafilomycin A1 alone caused increased DNA laddering of genomic DNA and increased nuclear staining for fragmented DNA in neonatal cardiomyocyte apoptosis in a dose- and time-dependent manner. Intracellular acidification in cardiac myocytes was also observed after 18 h of bafilomycin A1 treatment. Accordingly, bafilomycin A1-treated myocytes also showed increased accumulation of p53 protein and p53-dependent transactivation of gene expression, including a persistent upregulation of p21/wild-type p53 activated fragment 1/cyclin kinase inhibitor protein-1 mRNA. The bafilomycin A1-induced increase in p53 protein levels was accompanied by a marked increase in p53 mRNA accumulation. In contrast, cardiac fibroblasts treated with bafilomycin A1 showed no change in p53 protein expression or pHi and did not undergo apoptosis even after 24 h of treatment. Our data suggest that blockade of the VPATPase induces apoptotic cell death of cardiac myocytes and that this may occur through a p53-mediated apoptotic pathway.

[Diagnostic imaging of adhesions of the temporomandibular joint]

OBJECTIVE

To study the image diagnostic criteria of adhesions of the TMJ.

METHODS

26 cases of intra-articular adhesions were collected from 103 cases with internal derangement of TMJ. The clinical examination, arthrographic findings and arthroscopic detections were compared.

RESULTS AND CONCLUSION

The arthrographic findings showed that the lack, interruption and irregular joint margins of contrast material appeared in the superior space, the posterior band of disc appeared in the same relative position in both the closed and open views and intra-articular adhesion often associated with anterior disc displacement.

Stimulation of P2Y receptors activates c-fos gene expression and inhibits DNA synthesis in cultured cardiac fibroblasts

OBJECTIVES

The aims of this study were to determine (1) whether neonatal rat cardiac fibroblasts (CAFB) express P2Y receptors; (2) whether CAFB respond to extracellular ATP by inducing expression of c-fos mRNA; and (3) whether extracellular ATP modulates norepinephrine (NE)-stimulated cell growth in CAFB.

METHODS

Expression of P2Y1 and P2Y2 receptors and induction of c-fos were examined by Northern blot analysis. CAFB growth was assessed by measuring [3H]thymidine incorporation and DNA content. P2Y receptor pharmacology was studied using various ATP analogues.

RESULTS

Northern blot analysis of polyA enriched RNA confirmed that at least 2 subtypes of P2Y receptors (P2Y1 and P2Y2) are expressed in cultured CAFB. Extracellular ATP induced the expression of c-fos mRNA through a pathway that was sensitive to inhibitors of protein kinase C (PKC), but not to inhibitors of intracellular Ca2+ signaling. Extracellular ATP inhibited the NE-stimulated increases in DNA content and in [3H]thymidine incorporation into DNA. Whereas the potency order for stimulation of c-fos expression was ATP = UTP > ADP > adenosine, the potency order to inhibit the NE-induced increase of [3H]thymidine incorporation into DNA was ATP > ADP > UTP > adenosine.

CONCLUSIONS

These data demonstrate that CAFB express both P2Y1 and P2Y2 receptor mRNA and that CAFB respond to P2Y receptor stimulation by induction of c-fos and inhibition of DNA synthesis. These findings suggest that the effects of ATP on [3H]thymidine incorporation into DNA and on expression of c-fos mRNA are exerted via distinct P2Y receptor subtypes.

Rapamycin inhibits alpha 1-adrenergic receptor-stimulated cardiac myocyte hypertrophy but not activation of hypertrophy-associated genes. Evidence for involvement of p70 S6 kinase

The 70-kD S6 kinase (p70S6K) has been implicated in the regulation of protein synthesis in many cell types and in the angiotensin II-stimulated hypertrophy of cardiac myocytes. Our purpose was to determine whether p70S6K plays a role in cardiomyocyte hypertrophy induced by the alpha 1-adrenergic receptor (alpha 1-AR) agonist phenylephrine (PE). PE stimulated the activity of p70S6K > 3-fold, and this increase was blocked by rapamycin, an immunosuppressant macrolide that selectively inhibits p70S6K. When administered for 3 days, PE stimulated a 30% increase in total protein content, a 2-fold increase in the incorporation of [14C]phenylalanine (14C-Phe) into protein, and a 50% increase in two-dimensional myocyte area. Rapamycin pretreatment (> or = 500 pg/mL) significantly inhibited each of these PE-stimulated changes. Two days of PE treatment resulted in a 1.6-fold increase in total RNA yield per dish, a 2-fold increase in incorporation of [14C]uridine into myocyte RNA, and increases in relative mRNA levels of the hypertrophy-associated atrial natriuretic factor (ANF, 2.1-fold) and skeletal alpha-actin (SK, 2.2-fold) genes. Although rapamycin abolished the PE-stimulated increases in total RNA and incorporation of [14C]uridine, it had no effect on the induction of the ANF and SK genes. LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3-K) activity, inhibited PE-stimulated increases in p70S6K activity and the incorporation of labeled precursors into myocyte protein and RNA. These results demonstrate that p70S6K is activated by the hypertrophic agent PE and that a PI3-K or PI3-K-like activity is required for p70S6K activation and myocyte hypertrophy. The data suggest that p70S6K activation may be required for PE-stimulated hypertrophy of cardiac myocytes. Our results demonstrate that intracellular signaling pathways responsible for transcriptional and translational responses diverge early after alpha 1-AR stimulation in cardiac myocytes.

p53 and the hypoxia-induced apoptosis of cultured neonatal rat cardiac myocytes

Myocyte cell loss is a prominent and important pathogenic feature of cardiac ischemia. We have used cultured neonatal rat cardiac myocytes exposed to prolonged hypoxia as an experimental system to identify critical factors involved in cardiomyocyte death. Exposure of myocytes to hypoxia for 48 h resulted in intranucleosomal cleavage of genomic DNA characteristic of apoptosis and was accompanied by increased p53 transactivating activity and protein accumulation. Expression of p21/WAF-1/CIP-1, a well-characterized target of p53 transactivation, also increased in response to hypoxia. Hypoxia did not cause DNA laddering or cell loss in cardiac fibroblasts. To determine whether the increase in p53 expression in myocytes was sufficient to induce apoptosis, normoxic cultures were infected with a replication-defective adenovirus expressing wild-type human p53 (AdCMV.p53). Infected cells expressed high intracellular levels of p53 protein and exhibited the morphological changes and genomic DNA fragmentation characteristic of apoptosis. In contrast, no genomic DNA fragmentation was observed in myocytes infected with the control virus lacking an insert (AdCMV.null) or in cardiac fibroblasts infected with AdCMV.p53. These results suggest that the intracellular signaling pathways activated by p53 might play a critical role in the regulation of hypoxia-induced apoptosis of cardiomyocytes.

Increased cardiomyocyte apoptosis during the transition to heart failure in the spontaneously hypertensive rat

The transition from compensated hypertrophy to failure in spontaneously hypertensive rats (SHR) of advanced age is associated with a marked increase in collagen, a reduction in myocyte mass, and a reduction in maximum Ca(2+)-activated myofibrillar force. We hypothesized that the reduction in myocyte mass and associated functional loss may be due to increased cell death by apoptosis. To test this hypothesis, we studied hearts from failing (SHR-F) and nonfailing SHR (SHR-NF) and age-matched Wistar-Kyoto rats (WKY). In addition, hearts from SHR-F that had been treated with an angiotensin-converting enzyme inhibitor (captopril) for an average of 27 days were also studied. Apoptotic cells were quantified in cross sections of myocardium by the terminal deoxynucleotidyltransferase- mediated 2'-deoxyuridine 5'-triphosphate nick end labeling technique. To identify the type of the cells undergoing apoptosis, sections were also stained for alpha-sarcomeric actin. Apoptotic cells were significantly increased in the SHR-F (38.92 +/- 12.79 vs. 8.05 +/- 3.98 cells/100,000 nuclei in SHR-NF; P < 0.05 and vs. 2.21 +/- 1.4 cells/100,000 nuclei in WKY; P < 0.01). Captopril treatment of SHR-F reduced the number of apoptotic cells to the level in SHR-NF (9.17 +/- 1.53 cells/100,000 nuclei; P < 0.01 vs. SHR-F). Most apoptotic cells were of cardiac myocyte origin. There was no significant difference in Bcl-2 protein expressed by hearts among the three groups. WAF-1 mRNA levels were increased in both SHR groups vs. WKY; in SHR-F, the density of WAF-1 mRNA was higher than in SHR-NF. Thus increased numbers of apoptotic cells are present in failing SHR hearts, suggesting that apoptosis might be a mechanism involved in the reduction of myocyte mass that accompanies the transition from stable compensation to heart failure in this model. Administration of the angiotensin-converting enzyme inhibitor captopril, which ameliorates heart failure in this model, is associated with a reduction in the exaggerated apoptosis that accompanies heart failure.

Superior dislocation of mandibular condyle into the middle cranial fossa. A case report

A case of superior dislocation of the mandibular condyle into the middle cranial fossa is presented. A modified method of reducing the mandibular condyle was used, and restitution of the perforated glenoid fossa was achieved by a combination of titanium plate and repair of the articular disk.

Extracellular ATP inhibits adrenergic agonist-induced hypertrophy of neonatal cardiac myocytes

We have previously shown that extracellular ATP, like norepinephrine (NE) and many other hypertrophy-inducing agents, increases expression of the immediate-early genes c-fos and junB in cultured neonatal cardiac myocytes but that the intracellular signaling pathways activated by ATP and responsible for these changes differ from those stimulated by NE. Furthermore, whereas NE increases incorporation of [14C]phenylalanine (14C-Phe) and cell size in neonatal cardiomyocytes, ATP does not. Since ATP is coreleased with NE from sympathetic nerve endings in the heart, we investigated whether ATP could modulate cardiac hypertrophy induced by adrenergic agonists, such as NE. We report in the present study that extracellular ATP inhibited the increase in incorporation of 14C-Phe into cellular protein and the increase in cell size in neonatal rat cardiac myocytes that was induced by NE, phenylephrine (PE), basic fibroblast growth factor, or endothelin-1. This inhibition was dose dependent, occurred predominantly through P2 purinergic receptors, and was observed even when cells were treated with ATP for as little as 1 hour before the addition of the hypertrophy-inducing agent. ATP also selectively affected changes in gene expression associated with hypertrophy. It prevented PE-stimulated increases in atrial natriuretic factor and myosin light chain-2 mRNA levels, while appearing to augment basal and PE-stimulated skeletal alpha-actin mRNA levels. ATP alone increased sarcoplasmic reticulum Ca2+-ATPase mRNA levels but had no effect when added with PE. ATP did not significantly affect the level of the constitutively expressed mRNA for GAPDH. Neither the PE-stimulated increase in immediate-early gene expression nor the initial induction of mitogen-activated protein kinase activity by PE was inhibited by ATP. These results demonstrate that extracellular ATP can inhibit hypertrophic growth of neonatal cardiac myocytes and differentially alter the changes in gene expression that accompany hypertrophy.

Effect of interferon-gamma on antigen-induced eosinophil infiltration into the mouse airway

OBJECTIVE

To investigate whether murine recombinant interferon-gamma (IFN-gamma) is capable of inhibiting antigen-induced eosinophil (EOS) infiltration into the mouse airway.

MATERIALS AND METHODS

BALB/c mice were sensitized and challenged repeatedly with ovalbumin (OVA) to develop an allergic airway inflammation model. The experimental mice were given injection of different doses of IFN-gamma. The numbers of EOS in bronchoalveolar lavage fluid (BALF) from each group were counted, and concentrations of interleukin (IL)-5 in supernatants of cultured spleen cells were detected.

RESULTS

In sensitized mice challenged with OVA 20 minutes once a day for 6 days, the number of BLAF EOS was 9.53 +/- 0.84 x 10(5)/ml. However, no EOS could be found in BALF from mice without OVA sensitization and challenge. In mice treated with IFN-gamma, doses of IFN-gamma (1.0 x 10(3), 1.0 x 10(4), 1.0 x 10(5)U/KG) produced 29.8% (P < 0.05), 55.7% (P < 0.01), and 69.0% (P < 0.01) inhibition of eosinophilia, respectively. The results also showed that IFN-gamma prevented antigen-induced EOS recruitment into airway accompanied be decrement of levels of IL-5 with a dose-related response.

CONCLUSION

IFN-gamma is capable of inhibiting EOS infiltration into mouse airway by inhibiting the production of IL-5. Our results suggested that IFN-gamma may be of value in treating asthma in human beings.

Isoproterenol infusion induces alterations in expression of hypertrophy-associated genes in rat heart

Chronic infusion of isoproterenol (Iso) in rats results in cardiac hypertrophy via incompletely understood mechanisms. Our purpose was to determine whether Iso infusion would alter the expression of genes associated with hypertrophy. Male Wistar rats received either 2.4 mg Iso.kg-1.day-1, 9.9 mg propranolol (Prop).kg-1.day-1, both Iso and Prop, or vehicle (NaCl) via subcutaneously implanted osmotic pumps. In Iso-treated rats, the ventricular weight-to-body weight ratio was increased by 27% after 1 day and peaked on day 3 (+ 40%). Levels of atrial natriuretic factor (ANF) and fibronectin (FN) mRNA in the left ventricles were elevated 20-fold and 13-fold in Iso-treated rats, respectively, peaking at 3 days of infusion. The increase in FN mRNA accumulation was at least partially accounted for by elevated expression of extra type IIIA and IIIB (EIIIA and EIIIB) splicing variants. Levels of transforming growth factor (TGF)-beta 1 mRNA were elevated twofold after 3 days of Iso infusion. The abundance of skeletal alpha-actin (SK) mRNA increased fourfold after 1 day of Iso and declined thereafter. Iso infusion decreased sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) and preproenkephalin (PNK) gene expression by approximately 50% and induced a myosin heavy chain (MHC) isogene switch favoring beta-MHC. Prop partially inhibited the Iso-evoked increases in ANF and FN mRNA, completely prevented the Iso-induced changes in TGF-beta 1 and SERCA mRNA, but had no effect on the Iso-stimulated changes in SK and PNK gene expression. These results demonstrate that chronic Iso infusion elicits alterations in cardiac gene expression that are consistent with the development of myocyte hypertrophy and interstitial fibrosis and are directionally identical to those previously reported for pressure overload hypertrophy.

Helicobacter pylori-associated gastritis and gastric carcinoma in Beijing

A retrospective study was performed on 500 consecutive gastric biopsies obtained from patients with a diagnosis of gastritis and gastric carcinoma. Overall, Helicobacter pylori was detected in 336 cases (67.2%); it was seen in 82.4% of patients with duodenal ulcer, 80.1% of patients with gastric ulcer, 76.1% of patients with chronic atrophic gastritis, 60.3% of patients with chronic superficial gastritis, and 32.1% of patients with gastric carcinoma. The gastric epithelium colonized by Helicobacter pylori showed characteristic changes including loss of the apical mucous portion of individual cells, dropout of epithelial cells, and erosions. There is a strong suggestion that the inflammation associated with Helicobacter pylori infection plays a role in the pathogenesis of gastric carcinoma.

[Antifatigue and anoxia-tolerating effects of the root of Tragopogon porrifolius L]

The root of Tragopogon porrifolius can evidently prolong the duration of swimming and stick-climbing for mice. The drug has provided food for tolerating anoxia in several models of rats and mice.