Ameloblastoma is the most common clinically significant odontogenic tumor. It is considered benign but locally invasive and associated with variable clinico-pathological behavior. Ameloblastic carcinoma is a malignant tumor having features of ameloblastoma in addition to cytologic atypia with or without metastasis. It is aggressive and associated with poor prognosis. The aim of this study was to examine which epithelial and stromal markers are predictive of histologically diagnosed ameloblastic carcinoma and can sufficiently differentiate it from solid/multicystic ameloblastoma (SA). We examined immunohistochemically Ki-67, epithelial membrane antigen (EMA), alpha-smooth muscle actin (alpha-SMA), calponin, p63 and DNA content using image (ICM) and flow cytometry (FCM) in three ameloblastic carcinomas and up to 18 SAs. The important findings were that Ki-67 labeling index was significantly higher in ameloblastic carcinoma than SA while EMA, calponin, p63, ICM and FCM did not sufficiently differentiate the two groups of lesions. Expression of alpha-SMA was consistently obtained within the epithelial island cells of ameloblastic carcinoma and not in SA, although the marker was well expressed in the stroma of both lesions. We therefore conclude that the presence of alpha-SMA within the epithelial islands is highly predictive of ameloblastic carcinoma.
The chronicity of bronchial asthma is attributed to persistent airway inflammation and to a variety of structural changes, or remodelling, that includes smooth muscle and goblet cell hyperplasia. To investigate the mechanisms of airway remodelling, the current authors used an established allergen (ovalbumin; OVA)-driven rodent model (the Brown Norway rat). Brown Norway rats were sensitised to OVA and challenged three times at 5-day intervals to evoke airway remodelling. The effects of an epidermal growth factor (EGF) receptor inhibitor, AG1478, and a cysteinyl leukotriene-1 receptor antagonist, montelukast, on epithelial and airway smooth muscle (ASM) cell proliferation in vivo in response to repeated OVA challenge were tested. Three challenges with leukotriene (LT)D(4) were given, to examine their effects on remodelling with and without AG1478 pretreatment. OVA challenges caused ASM hyperplasia, with an increase in mass, epithelial cell proliferation and goblet cell proliferation. AG1478 prevented the changes, as did montelukast. Multiple OVA challenges increased heparin-binding EGF-like growth factor but not EGF expression by airway epithelium. LTD(4) reproduced the changes in remodelling induced by OVA and this was blocked by AG1478. Allergen-induced airway epithelial and airway smooth muscle remodelling is mediated by cysteinyl leukotrienes via the cysteinyl leukotriene-1 receptor with downstream effects on the epidermal growth factor receptor axis.
The content was studied of vasoactive intestinal peptide (VIP), substantia P (SP), bombesine (BMB), prostaglandins (PG) E2, F2alpha, 6-keto-F1alpha, Tx A2, and leukotrien (LT) B4 in the expired air condensate with the aid of the radioimmune technique to reveal a relation between pulmonary tachykinins and eicosanoids in obstructive type respiratory incompetence in patients with pulmonary tuberculosis. In patients with pulmonary tuberculosis, a high level of BMB was measurable in the expired air condensate. A linear negative correlation has been established between BMB content and forced expiratory volume, SP and respiratory volume, SP and lung capacity. In pulmonary tuberculosis, PGE2 and PGF2alpha levels are significantly evaluated. There was a positive correlation between BMB content and PGF2a in the expired air condensate, which fact suggests their synergic action on the smooth muscles of the bronchi and bronchioles.
Airway smooth muscle thickening is a characteristic feature of airway wall remodelling in chronic asthma. We have investigated the role of the leukotrienes in airway smooth muscle (ASM) and epithelial cell DNA synthesis and ASM thickening following repeated allergen exposure in Brown Norway rats sensitized to ovalbumin. There was a 3 fold increase in ASM cell DNA synthesis, as measured by percentage bromodeoxyuridine (BrdU) incorporation, in repeatedly ovalbumin-exposed (4.1%, 3.6-4.6; mean, 95% c.i.) compared to chronically saline-exposed rats (1.3%, 0.6-2.1; P
It was shown that vasodilatory effects of ATP-sensitive potassium channels opener--flocalin--depend from character of increase of initial vessel tone. Norepinephrine and angiotensin II partially inhibit effects of flocalin, thus they depressed of KATP channel activity. The inhibitory effect of angiotensin II increases under arterial hypertension conditions. It was shown that vasodilatory effects of flocalin significantly do not distinguish in experiments on normotensive and hypertensive rats under K(+)-depolarization conditions. While the vasodilatory effects acetylcholine on hypertensive rats are significantly diminished. These data suggests that flocalin could be a perspective substance for treatment of hypertension.
The effects of authentic nitric oxide (NO, 10(-6) M) and NO-donors such as sodium nitroprusside (SNP, 10(-5) M) and glyceryl trinitrate (GTN, 10(-4) M) on contractile force and free intracellular calcium level ([Ca2+]i) were studied on precontracted with high potassium chloride (KCl, 70 mM) isolated rings of rat tail artery. The sensitivity of contractile myofilaments to Ca2+ was measured using chemically permeabilized (alpha-toxin, beta-escin, Triton X-100) vascular rings. [Ca2+]i and contractile activity were measured simultaneously. The relationship of [Ca2+]i and tension developed was studied in endothelium-denuded rings and controlled calcium response was evaluated in both endothelium-denuded and permeabilized vascular rings. Both authentic NO and NO-donors decreased [Ca2+]i and high potassium-induced tension with a different time course. Inhibitor of soluble guanylyl cyclase (sGC) LY83583 (10(-5) M) did not affect SNP-induced relaxation whereas the other sGC inhibitor ODQ (10(-6) M) attenuated SNP-induced relaxation. Both inhibitors had no effect on NO- and SNP-induced reduction in [Ca2+]i. On the contrary, GTN induced neither relaxation nor decrease in [Ca2+]i on application of both LY83583 and ODQ. Tail artery rings permeabilized with alpha-toxin, beta-escin, but not with Triton X-100 were relaxed by authentic NO and NO-donors, but to a less extent than non-permeabilized rings. Dithioerythritol (DTE, 5 x 10(-3) M) that maintains sulfhydryl (SH) groups in reduced state preventing their nitrosylation attenuated NO-induced relaxation in both non-permeabilized and permeabilized tail artery rings. The cyclic heptapeptide mycrocystin-LR (MC-LR) (10(-5) M), an inhibitor of type 1 and 2A phosphatases, induced sustained increase in tension of beta-escin permeabilized rings in low Ca2+ (10(-8) M) solution. The tension was not affected by authentic NO and SNP. We conclude that authentic NO and SNP relax rat tail artery smooth muscle (SM) in the presence of inhibitors of sGC via cyclic guanosine monophosphate (cGMP)-independent pathway, whereas relaxation induced by GTN is inhibited. The data demonstrate that cGMP-dependent pathway in vascular smooth muscle is ubiquitous, but not the only way of relaxation induced by NO. NO can modulate vascular tone directly by reducing sensitivity of contractile myofilaments to [Ca2+]i and may involve activation of protein phosphatase(s).
Chronic inflammation in asthmatic airways can lead to characteristic airway smooth muscle (ASM) thickening and pathological changes within the airway wall. This study assessed the effect of repeated allergen exposure on ASM and epithelial cell deoxyribonucleic acid (DNA) synthesis, cell recruitment and airway wall pathology. Brown-Norway rats were sensitized and then exposed to ovalbumin or saline aerosol every 3 days on six occasions. After the final exposure, rats were administered twice daily for 7 days with the DNA S-phase marker bromodeoxyuridine (BrdU). Using a triple immunohistochemical staining technique, BrdU incorporation into ASM and epithelium was quantified employing computer-assisted image analysis. There were >3-fold mean increases in BrdU incorporation into ASM from 1.3% of cells (95% confidence interval (CI) 1.0-1.6) in saline controls to 4.7% (95% CI 2.6-6.7) after allergen exposure (p
Familial visceral myopathy (FVM) is a rare inherited form of myopathic pseudo-obstruction; little is known about the genetic factors that cause this disorder. FVM is characterized by impaired functions of enteric smooth muscle cells, resulting in abnormal intestinal motility, severe abdominal pain, malnutrition, and even death. We searched for genetic factors that might cause this disorder.
We performed whole-exome sequence analysis of blood samples from 2 individuals in a family that had 7 members diagnosed with FVM. Sanger sequencing was used to analyze additional family members and 280 individuals without this disorder (controls). Intestinal tissue samples from 4 patients and 2 controls were analyzed by immunohistochemistry. Functional studies, including immunofluorescence, cell contractility, and actomyosin structure analyses, were performed using CRL-1976 and U2OS sarcoma cell lines.
Whole-exome sequence analysis of DNA from 2 siblings identified 83 gene variants that were shared between the siblings and considered as possible disease-causing changes. A heterozygous variant, R148S in enteric smooth muscle actin ?-2 (ACTG2), segregated with disease phenotype. Intestinal smooth muscle (muscularis propria) from individuals with FVM had reduced levels of cytoplasmic ACTG2 and abnormal accumulation of the protein into intracellular inclusions compared with controls. Sarcoma cells that expressed exogenous ACTG2(R148S) incorporated reduced amounts of this protein into actin filaments compared with cells expressing ACTG2(wt) (P
Serum concentrations of myoglobin (S-Myo) and carbonic anhydrase III (S-CA III; EC 188.8.131.52), a skeletal muscle-specific protein, were measured by RIA in 26 patients with acute myocardial infarction, 14 patients with neuromuscular diseases, and six healthy subjects before and after physical exercise. S-Myo was increased in infarct patients, whereas S-CA III was not altered. In patients with neuromuscular diseases and in healthy subjects after physical exercise, both S-Myo and S-CA III were significantly increased. S-CA III and S-Myo also showed identical peak times, 2 h postexercise. The S-Myo/S-CA III ratio was always higher in infarct patients than in the other groups. Thus, the combination of S-CA III and S-Myo determinations is useful to differentiate whether serum myoglobin is originating from myocardium or from skeletal muscle.