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At least 595 records · Page 33Linked to original sources
PubMed2006

Long-term effects of a PPAR-gamma agonist, pioglitazone, on neointimal hyperplasia and endothelial regrowth in insulin resistant rats.

OBJECTIVE: Insulin resistance is an independent risk factor for cardiovascular disease. PPAR-gamma agonists like pioglitazone decrease insulin resistance and have been shown to reduce neointimal hyperplasia in the short-term. However long-term studies on endothelial regrowth and neointimal hyperplasia have not been done. METHODS AND RESULTS: We used hyperinsulinemic, normoglycemic Zucker fatty rats. Rats were treated with either 10 mg/kg body wt. pioglitazone or placebo till the end of the experiment. Rats underwent carotid angioplasty at age 12-14 weeks, 1 week after treatment was begun. In one set of experiments rats were sacrificed at 6 months and neointimal hyperplasia and VEGF expression was assessed. In another set of experiments rats were sacrificed at 3 and 6 months. Endothelial regrowth was determined. The rats were all normoglycemic and hyperinsulinemic. Pioglitazone treated rats had a significantly lesser degree of neointimal hyperplasia than control rats. Treated rats also had decreased VEGF expression. Endothelial regrowth was decreased in the treated rats at 6 months. CONCLUSION: We conclude that although pioglitazone decreases neointimal hyperplasia even at 6 months, it retards endothelial regrowth, which could predispose the denuded vessel to thrombotic events. This may be modulated by a suppression of VEGF expression.

Animals↗
PubMed2000

Pygeum africanum for the treatment of patients with benign prostatic hyperplasia: a systematic review and quantitative meta-analysis.

PURPOSE: To conduct a systematic review and quantitative meta-analysis of the therapeutic efficacy and tolerability of Pygeum africanum in men with symptomatic benign prostatic hyperplasia. METHODS: Studies were identified through the search of Medline (1966 to 2000), Embase, Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with relevant authors and drug companies. Randomized trials were included if participants had symptomatic benign prostatic hyperplasia, the intervention was a preparation of P. africanum alone or in combination with other phytotherapeutic agents, a control group received placebo or other pharmacologic therapies for benign prostatic hyperplasia, and treatment duration was at least 30 days. Two investigators independently extracted key data on design features, subject characteristics, and therapy allocation. RESULTS: A total of 18 randomized controlled trials involving 1,562 men met the inclusion criteria and were analyzed. Many studies did not report results in a method that permitted meta-analysis. Only 1 of the studies reported a method of treatment allocation concealment, although 17 were double-blinded. The mean study duration was 64 days (range 30 to 122). Compared with placebo in 6 studies, P. africanum provided a moderately large improvement in the combined outcome of urologic symptoms and flow measures as assessed by an effect size defined by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome (-0.8 SD [95% confidence interval (CI): -1.4 to -0.3]). Summary estimates of individual outcomes were also improved by P. africanum. Men were more than twice as likely to report an improvement in overall symptoms (risk ratio = 2.1, 95% CI: 1.40 to 3.1). Nocturia was reduced by 19% and residual urine volume by 24%; peak urine flow was increased by 23%. Adverse effects due to P. africanum were mild and similar to placebo. The overall dropout rate was 12% and was similar for P. africanum (13%), placebo (11%), and other controls (8%; P = 0.4 versus placebo and P = 0.5 versus other controls). CONCLUSIONS: The literature on P. africanum for the treatment of benign prostatic hyperplasia is limited by the short duration of studies and the variability in study design, the use of phytotherapeutic preparations, and the types of reported outcomes. However, the evidence suggests that P. africanum modestly, but significantly, improves urologic symptoms and flow measures. Further research is needed using standardized preparations of P. africanum to determine its long-term effectiveness and ability to prevent complications associated with benign prostatic hyperplasia.

Fatty Alcohols↗
PubMed1994

Incidence of endometrial hyperplasia in postmenopausal women taking conjugated estrogens (Premarin) with medroxyprogesterone acetate or conjugated estrogens alone. The Menopause Study Group.

OBJECTIVE: We evaluated four oral combinations of conjugated estrogens (Premarin) and medroxyprogesterone acetate in preventing endometrial hyperplasia, which can occur with conjugated estrogens alone. STUDY DESIGN: This was a 1-year prospective, double-blind, randomized, multicenter study in 1724 postmenopausal women. All five groups took conjugated estrogens (0.625 mg) daily. The respective medroxyprogesterone acetate dosages were 2.5 and 5.0 mg daily (groups A and B) and 5.0 and 10.0 mg for 14 days per 28-day cycle (groups C and D). RESULTS: Among the 1385 patients with valid biopsy data, endometrial hyperplasia developed in 20% in the conjugated estrogens-treated group and < or = 1% in each of the four conjugated estrogens/medroxyprogesterone acetate-treated groups. The incidence of endometrial hyperplasia did not differ significantly between any of the conjugated estrogens/medroxyprogesterone acetate regimens. However, none of the patients receiving the two higher medroxyprogesterone acetate dosages (groups B and D) had endometrial hyperplasia. CONCLUSION: The endometrial hyperplasia incidence was significantly lower in women treated with conjugated estrogens and medroxyprogesterone acetate than in women treated with conjugated estrogens alone.

Aged↗
PubMed1999

An evaluation of risk factors for endometrial hyperplasia in premenopausal women with abnormal menstrual bleeding.

OBJECTIVE: We sought to determine the clinical risk factors for endometrial hyperplasia in premenopausal women with abnormal bleeding. STUDY DESIGN: A laboratory database was searched to identify all endometrial samples taken in 1033 premenopausal women over a 30-month period from January 1995 to July 1997. Clinical data were extracted from the patients' clinical records retrospectively, and univariate and multivariate analyses were performed. The setting was the gynecologic service of a large teaching hospital. RESULTS: There were 46 cases of endometrial hyperplasia and 5 cases of endometrial cancer diagnosed. The following factors were independently associated with increased risk of endometrial hyperplasia or the presence of carcinoma: age >/=45 years (odds ratio, 3.1; 95% confidence interval, 1.5-6.1), weight >/=90 kg (odds ratio, 5.5; 95% confidence interval, 2.9-10.6), history of infertility (odds ratio, 3.6; 95% confidence interval, 1.3-9.9), family history of colonic carcinoma (odds ratio, 5.0; 95% confidence interval, 1.3-19.1), and nulliparity (odds ratio, 2.8; 95% confidence interval, 1.1-7.2). There was no increased association of endometrial hyperplasia on the basis of irregularity of menstrual cycle or duration of menstrual bleeding. CONCLUSIONS: The following are risk factors for endometrial hyperplasia in premenopausal women with abnormal menstrual bleeding: body weight >/=90 kg, age >/=45 years, infertility, family history of colonic carcinoma, and nulliparity. Current guidelines may need to be reconsidered.

Adolescent↗
PubMed2002

Pituitary hyperplasia in glycoprotein hormone alpha subunit-, p18(INK4C)-, and p27(kip-1)-null mice: analysis of proteins influencing p27(kip-1) ubiquitin degradation.

Most spontaneously developing hyperplastic and neoplastic lesions of the pituitary occur in the anterior pituitary. Targeted disruption of various cell-cycle proteins, including Rb, p27(kip1) (p27), and p18(INK4c) (p18), is associated with intermediate lobe pituitary hyperplasia. To develop a model of anterior pituitary proliferation to study the pathogenesis of pituitary tumors, we crossed the glycoprotein hormone alpha-subunit (alphaSU)-null mice that develop thyroid-stimulating hormone (TSH) cell hyperplasia with p18-null mice. The resulting offsprings developed accelerated enlargement of the anterior lobe with predominantly TSH cell hyperplasia. Immunohistochemical and histological analyses of these mice along with p27/p18 double-null mice, p18-null mice, and p27-null mice showed evidence of TSH, adrenocorticotropic hormone, prolactin, and luteinizing hormone hyperplasia. To determine whether there were alterations of p27 and the target proteins implicated in the ubiquitin degradation of p27 and other cyclin-dependent kinase inhibitors, we examined expression of SKP 2, Grb 2, and Jab 1 in the pituitaries of null mice. In the alphaSU-null mice there were decreased levels of SKP 2 and elevated levels of Grb 2 expression by Western blot analysis. Immunohistochemical analysis of the pituitary showed elevated Grb 2 in alphaSU-null and p18/alphaSU double-null mice. Jab 1 levels were not different from controls in the pituitary. These results show that 1) the p18/alphaSU double-null mice represent a good model to study the rapid development of anterior pituitary hyperplasia, and 2) various proteins important in p27 and other cyclin-dependent kinase inhibitor protein degradation are altered in the pituitary of alphaSU-null and p18/alphaSU double-null mouse models.

Animals↗
PubMed1996

Tranilast suppresses the vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet.

Intimal hyperplasia is a serious problem after percutaneous transluminal coronary angioplasty. In this study, we assessed the effect of tranilast on vascular intimal hyperplasia after balloon injury in rabbits fed on a high-cholesterol diet. In this animal model, intimal hyperplasia more severe than that in rabbits fed on a normal diet was observed. In addition, medial thickening and lipid deposits in both media and intima were also noted. These findings indicate that balloon injury caused intimal and medial hyperplasia and that this hyperplasia was accelerated by the high cholesterol load. Tranilast (300 mg/kg) significantly decreased the intimal area, medial area, and stenosis ratio, and increased the luminal/total area ratio, in the cholesterol-fed rabbits. These results suggest that tranilast may be useful for prevention of restenosis after percutaneous transluminal coronary angioplasty of patients, including those with a clinical risk of hypercholesterolemia.

Animals↗
PubMed1990

Late onset adrenal hyperplasia: mutation at codon 282 of the functional 21-hydroxylase gene is not ubiquitous.

Ten patients affected with 21-hydroxylase (21-OH) deficient late-onset adrenal hyperplasia were studied to determine the prevalence of a mutation at codon 281 of the functional 21-OH gene (CYP21B) that results in a valine to leucine amino acid shift. This mutation has been reported in eight unrelated late-onset adrenal hyperplasia patients of Ashkenazi Jewish descent possessing the human leukocyte antigen-B14,DR1 haplotype. Normally, there are two 21-OH genes; a pseudogene (CYP21A) and a functional gene (CYP21B). The aberrant codon 281 sequence is normally present only in CYP21A. In all of our late-onset adrenal hyperplasia patients, hybridization of an oligonucleotide probe specific for this mutation was demonstrated to CYP21A but not to CYP21B. The mutation at codon 281 of CYP21B does not appear to be a ubiquitous genetic marker for 21-OH deficient late-onset adrenal hyperplasia, suggesting that this disorder may demonstrate the same molecular heterogeneity as congenital adrenal hyperplasia.

Adrenal Glands↗
PubMed1997

Hepatic hyperplasia and cancer in rats: metabolic alterations associated with cell growth.

BACKGROUND & AIMS: We showed previously that the peroxisome proliferators di(2-ethylhexyl)phthalate (DEHP), clofibrate, and 4-chloro-6-(2,3 xylidino)-2-pyrimidinylthio (N-beta-hydroxyl)acetamide (BR931) alter hepatic sex steroid metabolism and receptor expression during induction of hepatic hyperplasia and hepatocellular carcinoma (HCC) in rats. The aim of this study was to identify metabolic changes associated with cell growth during hyperplasia and HCC. METHODS: Hepatic hyperplasia was induced in male rats by a diet containing DEHP and clofibrate for 3-60 days. HCC was induced by feeding a diet containing BR931, a more potent hepatocarcinogen, for 10 months. RESULTS: Cholesterol biosynthesis was depressed in hyperplastic livers but increased in HCC. Glucose-6-phosphate dehydrogenase (G6PD) activity was inhibited in hyperplastic liver as well as in HCC, whereas malic enzyme activity increased severalfold. Protein and messenger RNA (mRNA) levels for both G6PD and malic enzyme increased in hyperplastic livers and HCC. mRNA levels for 3-hydroxy-3-methylglutaryl-coenzyme A reductase decreased in hyperplasia and increased in HCC, whereas low-density lipoprotein receptor mRNA increased in hyperplasia and decreased in HCC. CONCLUSIONS: Neoplastic cells acquire a growth advantage by their capacity to synthesize cholesterol and obtain reduced nicotinamide adenine dinucleotide phosphate by the malic enzyme pathway when G6PD activity is inhibited by peroxisome proliferators.

Animals↗
PubMed1990

Prostate specific antigen in the staging of localized prostate cancer: influence of tumor differentiation, tumor volume and benign hyperplasia.

To evaluate the usefulness of serum prostate specific antigen in the preoperative staging of prostate cancer we examined tumor volume and differentiation, as well as benign prostatic hyperplasia volume to determine their influence on serum antigen levels. Serum prostate specific antigen was measured in 350 men with clinically localized prostate cancer and preoperatively in 72 men with documented benign prostatic hyperplasia. Although the mean antigen levels increased with advancing pathological stage, the usefulness of prostate specific antigen to predict pathological stage for an individual patient was limited: 1 of 102 men (0.9%) with prostate specific antigen levels of less than 2.8 ng./ml. had positive lymph nodes and 5 of 5 men with levels of greater than 100 ng./ml. had either seminal vesicle or lymph node involvement. However, for the majority of men (greater than 70%) with prostate specific antigen values between these 2 extremes the antigen levels did not accurately predict pathological stage. Because serum prostate specific antigen levels correlated with morphometrically determined tumor volume (r equals 0.535, p less than 0.01) they should, in fact, be predictive of pathological stage. However, most men with prostate cancer also have varying degrees of benign prostatic hyperplasia tissue in the gland producing prostate specific antigen. We have found that serum prostate specific antigen does not correlate with the volume of benign hyperplasia within the gland (r equals 0.21, p greater than 0.05). In addition, immunohistochemical studies have suggested that the lack of correlation between pathological stage and serum prostate specific antigen might be explained by a decrease in the production of antigen with increasing histological grade. Our findings of a negative correlation (r equals -0.37, p less than 0.01) between serum prostate specific antigen levels and Gleason score adjusted for tumor volume confirmed this suggestion. Consequently, serum prostate specific antigen levels do not reflect tumor burden and pathological stage accurately in individual patients for 2 reasons: 1) the unpredictable contribution from the benign prostatic hyperplasia component of the gland and 2) the decreasing production of prostate specific antigen by higher grade lesions as tumor volume increases.

Adenocarcinoma↗
PubMed1987

Phyllodes type of atypical prostatic hyperplasia: a report of 3 new cases.

We report 3 new cases of phyllodes type of atypical prostatic hyperplasia. This lesion is characterized by epithelial and stromal proliferation. Stromal changes are the most characteristic finding in phyllodes type of atypical prostatic hyperplasia, which show atypical cells with enlarged, hyperchromatic sarcomatoid nuclei. Mitotic figures are not present. Although the histological appearance may mimic that of cystosarcoma phyllodes of the breast, this pattern is present only focally or not at all in phyllodes type of atypical prostatic hyperplasia. On computerized tomographic imaging phyllodes type of atypical prostatic hyperplasia has a distinct appearance. These patients can be expected to have a benign clinical course and distant metastases have not been reported. Treatment is by surgical excision as in benign prostatic hyperplasia.

Adult↗
PubMed1997

Progestin treatment of atypical hyperplasia and well-differentiated carcinoma of the endometrium in women under age 40.

OBJECTIVE: To determine the efficacy of conservative management of atypical hyperplasia and well-differentiated carcinoma of the endometrium in women under age 40. METHODS: Pathology records were searched to identify women under age 40 diagnosed with atypical hyperplasia or well-differentiated carcinoma of the endometrium between January 1990 and January 1996. All available biopsy, curettage, and hysterectomy specimens were reviewed. Follow-up was obtained from the patients' gynecologists. RESULTS: Sixty-seven records were identified. Atypical hyperplasia was found in 32 patients and well-differentiated carcinoma in 35 patients. Seven patients were excluded from analysis; four declined all treatment and follow-up, and three received no further treatment or tissue sampling from their physicians. Among 27 remaining patients with atypical hyperplasia, eight underwent hysterectomy, two were treated with ovulation induction, and 17 were treated with progestins, of whom 16 had regression of their lesions, and one had a persistent lesion. Among 33 women with well-differentiated carcinoma, 19 underwent hysterectomy, one was treated with bromocriptine, one was treated with oral contraceptives, and 12 were treated with progestins, of whom nine had regression of their lesions and three had persistent lesions. The median length of treatment required for a regression was 9 months. At a mean follow-up of 40 months, all patients were alive and well without evidence of progressive disease. Twenty-five women attempted to become pregnant, and five delivered healthy, full-term infants. CONCLUSION: Treatment of atypical hyperplasia and well-differentiated carcinoma of the endometrium with progestins appears to be a safe alternative to hysterectomy in women under age 40.

Adult↗
PubMed2003

Plasmacytic hyperplasia--the early form of posttransplant lymphoproliferative disorder--with atypical morphology and clinical course in patient after liver transplantation: a case report.

This case report describes an early lesion of posttransplant lymphoproliferative disorder (PLTD)--plasmacytic hyperplasia with atypical morphology. The 54-year-old patient was 4 months after liver transplantation due to alcoholic cirrhosis. The postoperative course had been uneventful without graft rejection episodes. Primary immunosuppressive therapy included tacrolimus and prednisone. On admission to the hospital the patient showed rapidly increasing jaundice, hepatomegaly, anemia, thrombocytopenia, and significant leukocytosis. A biopsy suggested generalized infection. Acute Epstein-Barr virus (EBV) infection was confirmed using serological methods. Despite treatment the patient died. On autopsy we found features of generalized infection. Histological examination of the enlarged lymph nodes showed plasmacytic hyperplasia despite lymph node atrophy. Plasmacytic hyperplasia, an early lesion of PTLD despite usually a good prognosis with multifactor therapy may display a rapid course that leads to death through intensified immunosuppression. In accordance with other reports we confirmed reactivation of EBV infection as the probable cause of plasmacytic hyperplasia. The lymph node morphology of plasmacytic hyperplasia may be atypical with atrophy of lymphoid components accompanying plasma cell proliferation.

Biopsy↗
PubMed1976

Focal nodular hyperplasia of the liver: a clinicopathologic study and review of the literature.

We received the clinical records and pathologic material of 20 patients with biopsy proven hepatic focal nodular hyperplasia. The majority of the patients were females of child bearing age, five of whom had a history of oral use of contraceptives. In every instance focal nodular hyperplasia was an incidental finding; liver function tests were always normal. Focal nodular hyperplasia is a distinct histopathologic entity, distinguishable from liver cell adenoma. Specifically it consists of nodular aggregates of cytologically normal hepatocytes with foci of intranodular bile duct proliferation. Focal nodular hyperplasia appears to be a benign entity, even in patients in whom the lesion was not excised. The association between focal nodular hyperplasia and oral use of contraceptives may be coincidental, although hormonally related vascular changes may be responsible for rupture of the lesion.

Adolescent↗
PubMed1983

Cytodynamics of endometrial hyperplasia and neoplasia, Part II: in vitro DNA histoautoradiography.

The cytokinetics of normal, hyperplastic, and neoplastic human endometrium were evaluated by in-vitro double labeling with low- and high-dose radiothymidine. Relative to cyclic, proliferative endometrium, the mean S-phase duration was shorter in anovulatory, persistent proliferative endometrium, cystic glandular hyperplasia, and adenomatous hyperplasia without atypia, similar in adenomatous hyperplasia with severe atypia (AAH), and significantly prolonged in carcinoma in situ and invasive carcinoma. The S-phase patterns suggest a pathogenetic relationship between hyperplasias of increasing atypia as well as between hyperplasia and carcinoma, with carcinoma in situ as a transitional state between AAH and invasive carcinoma.

Adult↗
PubMed2001

Mechanisms involved in the inhibition of neointimal hyperplasia by abciximab in a rat model of balloon angioplasty.

Monoclonal antibodies raised against beta(3) integrin are able to inhibit the binding of ligands to certain beta(3) integrins such as alpha(IIb)beta(3) (glycoprotein IIb/IIIa complex) and alpha(v)beta(3) (vitronectin receptor) and as such are inhibitors of platelet aggregation and smooth muscle cell (SMC) migration, both of which are involved in neointimal hyperplasia. The present study was designed to explore the detailed mechanisms of abciximab (Reopro), a monoclonal antibody (mAb) raised against alpha(IIb)beta(3) integrin in neointimal hyperplasia. In this study, carotid arteries of Wistar rats were damaged, and neointimal hyperplasia and lumen occlusion was determined at different time points. Abciximab was administered intravenously by an implanted osmotic pump. Abciximab (0.25 mg/kg/day) time-dependently inhibited both neointimal hyperplasia and lumen occlusion after angioplasty in carotid arteries of rats. Furthermore, the electromicrographs highlighted that SMCs were phenotypically different from the typical contractile, spindle-shaped SMCs normally seen in uninjured vessel walls. Platelet-derived growth factor (PDGF)-BB was strongly produced in thrombus formation and neointimal SMCs after angioplasty, while abciximab significantly reduced PDGF-BB expression in vessel lumens and neointimal SMCs after angioplasty. Balloon angioplasty caused a significant increase of nitrate and cyclic GMP as compared with sham-operated rats. Infusion of abciximab (0.25 mg/kg/day) did not significantly change. Furthermore, the plasma level of thromboxane B(2) (TxB(2)) obviously increased after angioplasty, while abciximab markedly suppressed the elevation of plasma TxB(2) concentration. The results indicate that abciximab effectively prevents neointimal hyperplasia, possibly through the following 2 mechanisms: (1) Abciximab binds to alpha(IIb)beta(3) integrin on platelet membranes resulting in inhibition of platelet adhesion, secretion, and aggregation in injured arteries, followed by inhibition of thromboxane A(2) formation and PDGF-BB release from platelets. (2) Abciximab may also bind to alpha(v)beta(3) integrin on SMCs, thus, subsequently inhibiting cell migration and proliferation.

Abciximab↗
PubMed1998

Compliance mismatch may promote graft-artery intimal hyperplasia by altering suture-line stresses.

The role of graft-artery compliance mismatch in the development of distal anastomotic intimal hyperplasia (DAIH) is not yet resolved. Although DAIH develops at all surgically created anastomoses, increased compliance mismatch does not lead to greater hyperplasia formation in end-to-end anastomoses, but in end-to-side anastomoses, it leads to a profound increase in hyperplasia. The current study was undertaken to determine whether suture-induced anastomotic stresses could explain these findings. A large strain finite element analysis of vascular wall mechanics was performed to compare the influence of compliance mismatch on intramural stresses in end-to-end versus end-to-side anastomoses. A novel modelling approach was implemented which includes suture-induced stress concentrations. End-to-end and end-to-side graft-artery simulations were executed using (1) artery (compliance = C = 0.44% kPa(-1)), (2) vein (C = 0.33% kPa(-1)), and (3) Dacron (C = 0.14% kPa(-1)) grafts. Residual stresses due to axial tension were included and the anastomoses were statically inflated to 13.3 kPa (100 mmHg). Elevated intramural stresses were found to exist at both the end-to-end and end-to-side graft-artery junctions; however, in the end-to-end anastomosis, the maximum anastomotic stress was not a function of the graft compliance, whereas in the end-to-side anastomosis, the maximum stress was a strong function of graft compliance. For the 45 degree end-to-side geometry considered in this study, the maximum anastomotic stress concentration obtained using a stiff Dacron graft was more than 40% greater than that obtained using a compliant artery graft. In the end-to-end anastomosis, the Dacron graft led to a less than 5% increase in maximum stress over the artery graft. Therefore, increased compliance mismatch increases stresses and promotes DAIH in end-to-side junctions, but, it has little influence on either stresses or DAIH in end-to-end junctions. Thus, the proliferative influence of increased compliance mismatch on suture-line hyperplasia in end-to-side anastomoses can be explained by the resulting increase in intramural stresses. In addition, since high stresses were found in both geometries, elevated suture-line intramural stresses may be an important proliferative stimulus for intimal hyperplasia formation in all vascular reconstructions.

Arteries↗
PubMed1986

Condylar hyperplasia. A clinico-pathological analysis of 22 cases.

A series of 22 cases of unilateral condylar hyperplasia is presented with the emphasis on histopathological aspects. It is concluded that there are two types of condylar hyperplasia. The first manifests itself in the adolescent or the young adult and represents an exaggerated, normally proceeding growth and maturation process. The histological structure of the condyle in these cases is age-dependent as is shown by a conversion of hyaline growth cartilage into fibrocartilage occurring at about 20 years of age. The second type of condylar hyperplasia, seen in older people, probably represents reactive growth as a response to an eliciting agent that mostly can be identified. In these cases the histological architecture of the condyle is distorted by large masses of hyaline cartilage while there are concomitant degenerative changes in the form of arthrosis. In contrast to the patients suffering from the first type of condylar hyperplasia, the latter ones complain of additional joint symptoms, mostly pain. Moreover it is concluded that joint scintigraphy does not clearly discriminate between genuine condylar hyperplasia and reactive processes due to arthrosis, which may have clinical implications.

Adolescent↗
PubMed1997

Effect of nicotine on the intimal hyperplasia after endothelial removal of the rabbit carotid artery.

1. The present experiments were designed to investigate the effect of long-term oral nicotine (10 mg/200 ml/kg/day for 7 weeks) on the intimal hyperplasia after endothelial removal of the rabbit carotid artery. 2. The plasma concentrations of nicotine were determined to be 11.7-12.5 ng/ml during the term of administration and corresponded to the plasma levels in human smokers. 3. Six weeks after the endothelial removal, light microscopy revealed a marked intimal hyperplasia. Administration of nicotine tended to accelerate the intimal hyperplasia, which was estimated by comparing the histological findings, DNA content and wet weight of the vessel wall. 4. Acetylcholine- and A23187-induced endothelium-dependent relaxations were greatly impaired in the hyperplastic artery strips. The impairment of relaxations tended to be accelerated in the nicotine group. Sodium nitroprusside-induced relaxation was not different between the control and the hyperplastic artery strips and remained unaffected in the nicotine group. 5. The concentrations of endogenous nitric oxide (NO) synthesis inhibitors, NG-monomethyl-L-arginine (L-NMMA) and asymmetrical NG,NG-dimethyl-L-arginine (ADMA) were significantly more increased in the regenerated endothelial cells compared with those in the control endothelial cells. The concentrations of L-NMMA and ADMA in the regenerated endothelial cells were significantly increased by as much as 1.3 x 10(-6) and 5.6 x 10(-7) M, respectively, in the nicotine group. 6. Immunoreactive endothelin-1 was significantly increased in the hyperplastic vessel wall (2.4 times that of the control) in 6 weeks. Administration of nicotine tended to increase the level. 7. It seems possible to assume from these results that, although, under the present experimental conditions, nicotine exhibited a tendency to accelerate the intimal hyperplasia after endothelial removal, the longer exposure to nicotine or a higher dose of the agent or both would significantly accelerate the intimal hyperplasia through the enhanced impairment of endothelium-derived relaxing factor/ NO production, which might be brought about by the enhanced increases in L-NMMA and ADMA concentrations, and the enhanced increase in endothelin-1 in the vessel wall.

Animals↗