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PubMedDate not supplied

[The histotopographical characteristics of the muscular structures of the wall of the human esophagus in the area of the bronchial constriction].

The zone of the bronchial constriction of the esophagus and the area of the upper and lower dilatation of the esophagus was studied in humans of different age by the morphohistotopographic method at the macro- and microscopic levels. The bronchial constriction area of the esophagus was found to have a thickening of the circular layer of the muscular tunic, less relative thickness of the longitudinal layer, changed course of muscular fibers. The smooth muscle thickening of the circulating layer of the muscular tunic is localized at the boundary of the transitional zone of the displacement of the striated muscle fibers by smooth myocytes. The above morphological signs are characteristic of the areas with sphincter functions which allows to consider the bronchial constriction as a sphincter zone of the esophagus.

Adult↗

PubMed1993

[Retinal vein occlusion. III. Arteriolar constriction].

The author assumes that the process of the adjustment of the disproportion between the arterial and the venous volume can be favourably influenced by a decrease in the offered arterial volume to the venous occluded blood path. This can be achieved by a narrowing of the input arteriole with the help of the method of arteriolar constriction using the argon laser. The author is of the opinion that the method of arteriolar constriction finds its application especially in the treatment of severe prognostically unfavourable forms of occlusion of the branch of the retinal vein with presence of extensive hemorrhages in the retina. In such severe forms of occlusion, the author recommends to apply the arteriolar constriction already in the early acute phase of the disease.

Arterioles↗

PubMed1995

Are there different ETB receptors mediating constriction and relaxation?

Because certain antagonists of endothelin (ET) ETB receptors (such as the mixed ETA+ETB antagonist PD 142893 or the selective ETB receptor antagonist BQ-788) were shown to antagonize the ETB-mediated dilatation to ET-1 but not the ETB-mediated constriction to ET-1, the existence of two subtypes of to ET-1, the existence of two subtypes of ETB receptors was suggested. The goal of the present study was to further explore this absence of functional antagonism of ETB-mediated constriction by so-called ETB receptor antagonists. In rat tracheal rings denuded of epithelium, Ro 46-8443, a selective ETB receptor antagonist, did not shift the concentration-response curve of ET-1 but antagonized sarafotoxin S6c-induced contractions. However, the ET-1-mediated contractions could be attributed to ETB receptor activation, because BQ-123 had no inhibitory effect except at high doses of ET-1. Preincubation of tracheal rings with BQ-123 (10(-5) M) to block ETA receptors revealed an antagonist effect of Ro 46-8443 on contractions induced by ET-1. By analogy with these pharmacologic experiments, desensitization of ETB receptors by preincubation with sarafotoxin S6c did not modify contractile responses to ET-1 except when the tracheal rings were exposed to BQ-123. We conclude that on rat tracheal rings, ET-1 and sarafotoxin S6c activate a common ETB receptor. However, blockade of ETB receptors is not sufficient for inhibition of ET-1-mediated responses because of cross-talk between receptors that allows ETA to compensate for a blockade of ETB receptors. This study suggests that the endothelial ETB receptor mediating dilatation and the smooth muscle cell ETB receptor mediating constriction may not represent two different subtypes.

Animals↗

PubMed1998

[Effect of epidural anesthesia on airway constriction induced with methacholine or capsaicin in cats].

The choice of epidural anesthesia for patients with bronchial asthma is controversial. We studied the effect of epidural anesthesia on airway constriction induced by methacholine or capsaicin in cats. Cats were anesthetized with pentobarbital and mechanically ventilated. Peak airway pressure and compliance, as well as cardiac sympathetic and vagal nerve activity were recorded. We sprayed 0.2% methacholine of 0.2% capsaicin into the trachea to produce airway constriction, and 15 min after drug spray we injected 2% lidocaine 1.0 ml into the epidural space. Methacholine increased peak airway pressure by 25% and decreased compliance by 26%. Capsaicin increased peak airway pressure 20% and decreased compliance 22%. After epidural anesthesia, cardiac sympathetic nerve activity decreased to 40% and 44%, vagal nerve activity decreased to 92% and 61% of control values in methacholine and capsaicin groups, respectively. However, here were no changes in the peak airway pressure and compliance in the two groups. These results suggest that epidural anesthesia, even if epidural anesthesia decrease sympathetic nerve activity, has no effect on the airway constriction induced with methacholine or capsaicin.

Action Potentials↗

PubMed1991

[Value of magnetic resonance imaging in 2 cases of annular constriction of the ventricles].

Chronic pericarditis can take the form of localised annular bands constricting the atrioventricular grooves, the pulmonary infundibulum and, rarely, the atria. The authors report two cases of pericardial bands surrounding the ventricles and involving the atrioventricular groove resulting in a biloculation of the left ventricle. One case was complicated by adiastole and one by mitral regurgitation due to involvement of the posterior mitral leaflet. Magnetic resonance imaging gave precise definition of these bands and of their extension into the myocardium. This investigation was a valuable complement before surgery of the localised constriction.

Calcinosis↗

PubMed1976

Limits of constriction in the treatment of retinal detachment.

A constricting silicone band was added to 13% of local sponge buckle operations in this series. The purpose was to relieve circumferential traction or to maintain a high buckle. The inclusion of a cerclage did not require drainage of subretinal fluid. The rate of reattachment without drainage (42 of 50 detachments) is comparable to what might be expected if the subretinal fluid had been drained. Constriction was controlled and limited to between 10% and 25% of the circumference of the eye. Anterior segment ischemia requiring relaxation of the band occurred in two patients; scleral erosion did not occur.

Animals↗

PubMed1976

Growth failure with pericardial constriction. The syndrome of mulibrey nanism.

The features of the syndrome of mulibrey nanism, an autosomal recessive disorder of unknown pathogenesis, include severe growth failure, yellow pigmentation of the retina, evidence of pericardial constriction, J-shaped sella turcica, and fibrous dysplasia of bones. To date, 24 individuals from Finland and a boy from Egypt have been reported with the syndrome. The patient reviewed in this article is the first known affected child from the United States. It is important that physicians look for this disorder in children with severe growth failure and hepatomegaly because of the potential seriousness of undetected pericardial constriction.

Bone and Bones↗

PubMedDate not supplied

Constrictive pericarditis in systemic lupus erythematosus. Demonstration of immunoglobulins in the pericardium.

A 17-year-old male with systemic lupus erythematosus presented with clinical signs of severe constrictive pericarditis that was confirmed by cardiac catheterization. At surgery, a fibrous pericardium was removed, followed by complete relief of symptoms. Immunopathology of the pericardial tissue revealed deposition of IgG, IgM, and C3. A review of the literature produced only three similar cases. Although rare, constrictive pericarditis, a potentially life threatening complication, may occur in systemic lupus erythematosus presumably with an immunological basis.

Adolescent↗

PubMed2006

B-type natriuretic peptide level in a patient with constrictive pericarditis.

We report the case of a 35-year-old man with constrictive pericarditis who had a B-type natriuretic peptide (BNP) level of 129 pg/dl despite a left ventricular end diastolic pressure of 35 mmHg. We discuss a possible explanation for the relatively low BNP level given this patient's markedly elevated intracavitary pressures in the setting of constrictive pericarditis.

Adult↗

PubMed1988

Severe constrictive pericarditis as an unsuspected cause of death in a patient with idiopathic hypereosinophilic syndrome and restrictive cardiomyopathy.

A 43-year-old man with idiopathic hypereosinophilic syndrome survived a relatively long term (6 1/2 years) before he succumbed to intractable heart failure. Six months before death, his chronic heart failure from restrictive cardiomyopathy was well compensated. Autopsy demonstrated severe constrictive pericarditis which was not suspected antemortem. Constrictive pericarditis as a late complication of idiopathic hypereosinophilic syndrome is discussed.

Adult↗

PubMed1996

Constrictive pericarditis causing extrinsic mitral stenosis and a left heart mass.

Constrictive pericarditis is a fibrotic process involving both layers of the pericardium and is known to give rise to obstruction to blood flow in the right heart. We report a patient with constrictive pericarditis who had echocardiographic features of mitral stenosis caused by a fibrocalcific mass lesion involving the mitral annulus with infiltration into the base of the posterior mitral leaflet. To our knowledge, this has not been reported in the literature.

Biopsy, Needle↗

PubMed1994

Alteration in vascular reactivity in isolated aortic rings from portal vein-constricted rats.

It has been suggested that increased production of nitric oxide by an inducible nitric oxide synthase isoenzyme is important in the pathogenesis of the vascular abnormalities seen in human beings and animals with portal hypertension. We investigated this hypothesis by studying the in vitro vascular reactivity of isolated aortic rings from portal vein-constricted and sham-operated rats. Aortic rings from portal vein-constricted rats exhibited significantly impaired contractility to phenylephrine and potassium chloride compared with control rats. Preincubation with the nitric oxide synthase inhibitor nitro-L-arginine methyl ester significantly increased contractility to phenylephrine and potassium chloride in both portal-hypertensive and control tissues, with greater effect in the portal-hypertensive rings. Despite nitro-L-arginine methyl ester, maximal contractions were still significantly smaller in the portal-hypertensive tissues. Vascular relaxation evoked by acetylcholine, but not by the endothelium-independent vasodilator glyceryl trinitrate, was significantly impaired in the portal-hypertensive group. Our results demonstrate significant impairment in vascular function in aortic rings in this model of portal hypertension. The addition of a nitric oxide synthase inhibitor partly corrected these changes, suggesting that although nitric oxide is likely an important mediator, other factors may also be involved in the pathogenesis of these alterations in vascular function.

Acetylcholine↗

PubMed2002

Degree of fetal umbilical venous constriction at the abdominal wall in a low-risk population at 20-40 weeks of gestation.

OBJECTIVES: To determine the degree of constriction of the umbilical vein at the abdominal wall in the second half of pregnancy. METHODS: A total of 283 low-risk singleton pregnancies were recruited for a cross-sectional study, and examined once at 20-40 weeks of gestation. Two sets of ultrasound measurements of the umbilical vein were taken: one at the fetal end of the umbilical cord and another at the inlet through the abdominal wall, the umbilical ring. The diameter was determined as an average of >or=5 repeat measurements. The blood velocity was recorded at the same site. RESULTS: The time-averaged maximum venous blood velocity in the cord was low (mean 13-19 cm/s during 20-40 weeks of gestation), and the corresponding mean diameter 3.6-8.2 mm. In contrast, the mean of the venous blood velocity at the umbilical ring was 34-41 cm/s and the diameter was 2.8-5.9 mm during the same period. Of 191 pairs of observations, 41 (21%) had a velocity increment of >or=300 %, which corresponds to a diameter reduction to half or more at the umbilical ring. CONCLUSION: Constriction of the umbilical ring is a common phenomenon in the second half of pregnancy.

Adult↗

PubMed2004

Idiopathic constriction of the fetal ductus arteriosus.

Constriction of the ductus arteriosus in the fetus is well studied, but mostly secondary to maternal exposure to indomethacin or other non-steroidal anti-inflammatory medications, or structural cardiac lesions. We present a case of a fetus presenting with right ventricular hypertrophy secondary to an S-shaped ductus arteriosus with distal constriction diagnosed by pulsed Doppler imaging. A review of the recent English literature of similar cases is presented.

Adult↗

PubMed2001

Pro- and anti-inflammatory cytokine gene expression in rat sciatic nerve chronic constriction injury model of neuropathic pain.

Cytokines may be pathophysiologically involved in hyperalgesia. Uncertainty exists about the types of cytokines and their site of action. To study the role of key pro- and anti-inflammatory cytokines in a chronic constriction model of neuropathic pain, mRNA expression of TNF, IL-1beta, IL-6, and IL-10 was quantified using competitive RT-PCR. Each cytokine mRNA in rat sciatic nerve was examined at days 3, 7, 14, and 45 after chronic constriction injury (CCI). We also undertook behavioral testing of these rats. Thermal warming and touch thresholds were significantly reduced at days 3, 7, and 14 in the CCI group, compared with the sham-operated group. Cytokine gene expression in sciatic nerve was significantly increased at day 7 for IL-1beta and IL-6 and at day 14 for TNF. Expression of IL-10 underwent a gradual and progressive increase, reaching statistical significance at day 45.

Animals↗

PubMed1990

Prevention of alpha-adrenergic coronary constriction by calcium-antagonists.

This manuscript reviews the experimental evidence for a functional antagonism of Ca-antagonists against alpha-adrenoceptor-mediated increases in coronary vasomotor tone. In studies on anesthetized dogs, intravenous nifedipine effectively prevented the alpha 1-adrenoceptor-mediated increase in epicardial coronary resistance, as well as the increase in end-diastolic resistance mediated by both alpha 1- and alpha 2-adrenoceptors during cardiac sympathetic nerve stimulation. Both intracoronary and intravenous administration of nifedipine also prevented the alpha 2-adrenoceptor-mediated increase in coronary resistance distal to severe stenoses, as well as the resulting ischemic dysfunction and net lactate production during cardiac sympathetic nerve stimulation. Felodipine was equally effective as nifedipine in preventing an alpha 2-adrenoceptor-mediated increase in coronary resistance and the resulting contractile dysfunction distal to severe coronary stenoses. alpha 1- and alpha 2-Adrenergic coronary constriction also contribute to the severity of myocardial ischemia in conscious dogs during treadmill exercise. Again, nifedipine improved regional myocardial blood flow and attenuated regional contractile dysfunction during exercise-induced ischemia in conscious dogs with a chronic coronary stenosis. This beneficial effect of nifedipine was attributed to a recruitment of coronary dilator reserve and not to a reduction in heart rate or afterload. In conclusion, there is solid experimental evidence for a functional antagonism of Ca-antagonists against alpha-adrenergic coronary constriction and its contribution to myocardial ischemia.

Animals↗

PubMed1992

Transient cardiac constriction following purulent pericarditis.

Transient cardiac constriction is an unusual complication of purulent pericarditis. It should be suspected in the presence of clinical and haemodynamic deterioration when signs of activity have abated. Features of cardiac constriction were observed in a 4-year-old boy 2 weeks after surgical drainage. The patient was managed conservatively without surgery and the outcome was good. Follow up 2 years later showed a healthy boy with a normal cardiological examination.

Acute Disease↗

PubMed1978

Left ventricular function studies in constrictive pericarditis.

Left ventricular function studies were performed on five patients with constrictive pericarditis. Functional data were obtained from intracardiac pressure measurements and cineangiocardiographic films. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), ejection fraction (EF), stroke work index (SWI), circumferential fiber shortening, and percent circumferencial shortening were significantly below normal values in the five cases. These changes are reflected mainly in the degree of pericardial restriction. Reduction in mean Vcf was also observed. Theoretically, the velocity of ventricular internal circumferential shortening is also affected by changes in ventricular volume or resting myocardial fiber length, however, in patients with constrictive pericarditis, reduction in mean Vcf suggests left ventricular dysfunction. Our clinical studies indicate that evaluation of mean Vcf is valuable in the assessment of postoperative prognoses.

Adolescent↗