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At least 1,423 records · Page 79Linked to original sources
PubMed1983

Myosin isozyme changes in the heart following constriction of the ascending aorta of a 25-day old rat.

When a constricting band is placed around the ascending aorta of young (25-day old) rats, all chambers of the heart eventually produce hypertrophy. Both the left and right ventricles show strong shifts toward an isozyme pattern in which V3 is predominant, similar to that seen in models where hypertrophy is induced in adult rats. The hypertrophied atria however, show no detectable change in the native myosin isozymes or the light chain subunits.

Animals↗
PubMed1987

Effect of expiratory glottic constriction on lung volume and pattern of breathing in adult dogs.

We examined the effect of laryngeal constriction on the pattern of breathing in 4 anaesthetized adult mongrel dogs. By means of a T-shaped tracheostomy tube the larynx could be repeatedly excluded or included in the breathing circuit. Marked expiratory activity of the thyroarytenoid muscle (TA), the main glottic constrictor, was induced by injection of 100-400 ml of air into the pleural space or by inhalation of histamine aerosol (2 dogs) which resulted in rapid shallow breathing. In 21 pairs of runs in the 4 dogs switching from tracheostomy breathing to oral breathing decreased mid-expiratory flow and frequency by 85 +/- 2% (P less than 0.001) and 48 +/- 4% (P less than 0.001), respectively. Although expiratory duration (TE) increased, end-expiratory lung volume also increased by 40 +/- 8 ml or 21 +/- 4% of the tidal volume (VT) during tracheostomy breathing (P less than 0.001). In contrast, VT remained unchanged (P = 0.9). Instantaneous ventilation decreased due to both the prolongation of TE and an increase in inspiratory duration. Our results indicate that laryngeal braking can be recruited in adult dogs and interacts with reflex mechanisms that modulate respiratory timing, thereby significantly influencing end-expiratory lung volume, ventilation and the pattern of breathing. Simulation of the laryngeal mechanism by expiratory resistive loading at the tracheostomy below the larynx points to a non-reflex mechanical effect of the larynx as a resistance in series.

Aerosols↗
PubMed1987

Angiographic evidence of basilar artery constriction in the rabbit: a new model of vasospasm.

The main objective of this study was to produce angiographic evidence of basilar artery constriction using the rabbit model. The technique described involves the transdural injection of blood into the cisterna magna on two different days. The results obtained show that vasoconstriction occurs over a time period that is comparable in duration to that seen in patients undergoing vasospasm as a result of subarachnoid hemorrhage. Further investigation should be done to evaluate the usefulness of the rabbit model as a verifiable tool in studying the etiology of vasospasm.

Animals↗
PubMed1992

Biphasic constriction of rabbit basilar artery following experimental subarachnoid hemorrhage: a morphometric study.

To assess the changes in arterial structure resulting from subarachnoid hemorrhage, morphometric analysis was performed on basilar arteries from rabbits that had received an experimental subarachnoid hemorrhage up to 6 days earlier. For morphometric determination, the cross-sectional area of the media, the area of the lumen, and the length of the internal elastic lamina were measured planimetrically. The morphometric diameter of the lumen, the media-to-radius ratio, and several other morphometric parameters were also calculated. Subarachnoid hemorrhage induced significant biphasic constriction of the basilar artery without any changes in the cross-sectional area of the media. The relative amount of smooth muscle cell decreased significantly in the late stage of hemorrhage.

Analysis of Variance↗
PubMed1985

Pupillary constriction evoked from the posterior medial lateral suprasylvian (PMLS) area in cats.

Pupillary constriction was evoked by systematic stimulation using a microelectrode in the upper medial bank of the middle suprasylvian sulcus in the parieto-occipital cortex of the cat. The pupillo-constrictor area corresponded to the rostral and middle parts of the posterior medial lateral suprasylvian (PMLS) area. This pupillo-constrictor area extended by 2-3 mm along the middle suprasylvian sulcus. It is suggested that this pupillo-constrictor area overlaps or lies in close proximity of a part of the region in PMLS area related to lens accommodation, in which unit activity temporally related to lens accommodation was recorded and from which lens accommodation was evoked by electric stimulation.

Accommodation, Ocular↗
PubMedDate not supplied

Quantitative autoradiographic analysis of [125I]-human CGRP binding sites in the dorsal horn of rat following chronic constriction injury or dorsal rhizotomy.

Quantitative receptor autoradiography was used to examine the binding of [125I]-human CGRP in the dorsal horn of the L4 spinal segment of rats with a chronic constriction injury (CCI) of the sciatic nerve or unilateral dorsal rhizotomies of spinal segments L1-L6. At the times selected for study, we found no change in the amount of CGRP binding in any areas examined following CCI. In contrast, our results showed a temporally related increase in the amount of CGRP binding in areas within laminae I-II and in lateral lamina V of the dorsal horn ipsilateral to the rhizotomies. These results indicate that CGRP binding sites are regulated, most likely, by changes in the release of CGRP. Further, our results suggest that the release of CGRP from primary afferent neurons is unchanged in animals with a CCI.

Animals↗
PubMed1996

Hydralazine-induced constrictive pericarditis.

A 59-year-old man was diagnosed as having constrictive pericarditis 17 months after a typical hydralazine-induced autoimmune syndrome. This late complication of hydralazine has been reported only once. Ten years later the patient was found to have anti-neutrophil cytoplasmic antibodies directed against myeloperoxidase.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1995

Multiple protracted cauda equina constrictions cause deep derangement in the lumbosacral spinal cord circuitry in the dog.

Neuropathological changes of the neuronal pools and spinal cord circuitry in the lumbosacral segments were studied in a canine model of multiple protracted cauda equina constrictions. Anterograde degeneration of all sacrococcygeal and L7 dorsal root fibers was detected in S1-S3 and lower lumbar segments. A narrow degenerated gracile fascicle was found in all thoracic and cervical segments terminating in the gracile nucleus. Transneuronal degeneration of middle-sized and large neurons, located in S1-S3 and sporadically in L7 segments, was noted. Identical transneuronal degeneration was seen in a group of small neurons located in the ventralmost part of lamina VII in S1-S3 segments. Simultaneously, a terminal degeneration was detected in the lateral cervical nucleus and in the ventral posterior lateral nucleus of the ventrobasal thalamic complex. Concomitantly, a fully developed retrograde degeneration affecting motoneurons in the ventrolateral portion of the anterior horn in S1-S3 segments appeared.

Animals↗
PubMed1996

Fos-like immunoreactivity increases in the lumbar spinal cord following a chronic constriction injury to the sciatic nerve of rat.

A chronic constriction injury (CCI), transection injury, or sham injury to the sciatic nerve was induced in 30 rats. Rats were then sacrificed at 1, 3, 5, 10, and 20 days following injury, and the number of cells immunohistochemically labeled for Fos-like immunoreactivity (Fos-LI) was determined in random sections from the lumbar 4 and 5 (L4 and L5) spinal segments. Non-parametric statistics (Wilcoxon) were used to compare the number of labeled cells ipsilateral to the injury to the number of labeled cells on the contralateral side. At 1 and 5 days following injury, in all treatment groups, significantly more labeled cells (P < 0.05) were observed ipsilaterally. In addition, at 3 and 10 days following injury, the CCI groups exhibited significantly more labeled cells ipsilaterally. The significant increases for the CCI groups ranged from 161% to 360%. Generally, increases were greater for the CCI groups. These results indicate that Fos-LI increases to a greater extent and for a longer duration following the CCI than following either a transection or sham injury.

Animals↗
PubMed1990

Transsynaptic degeneration in the superficial dorsal horn after sciatic nerve injury: effects of a chronic constriction injury, transection, and strychnine.

The lumbar and cervical spinal dorsal horns of adult rats with a chronic (8 days) constriction injury of the sciatic nerve on one side (and a sham operation on the other) were examined for signs of transsynaptic degeneration. The incidence of neurons with signs of degeneration (pyknosis and hyperchromatosis; 'dark neurons') was significantly increased in the lumbar dorsal horn on both sides. The ipsilateral lumbar increase was significantly greater than the contralateral increase. There was no increase in the incidence of dark neurons in the cervical dorsal horns of the same rats. The distribution of lumbar dark neurons was similar bilaterally. The majority of the dark neurons were found in the sciatic nerve's territory in laminae I-II. A second group of rats received the same surgery but in addition received a series of 7 daily subconvulsive doses of strychnine. Dark neurons were again found bilaterally (with ipsilateral predominance) in the sciatic nerve's territory in lumbar laminae I-II, but the incidence was significantly greater than that found in the group that did not receive strychnine. The same result was obtained in a third group of strychnine-treated rats when the sham operation was omitted. Thus the appearance of contralateral dark neurons is not dependent on unintentional nerve damage created by the sham procedure. An additional group of rats was sacrificed 8 days after receiving a unilateral sciatic nerve transection, a contralateral sham operation, and the 7 daily strychnine injections. There was no increase in the incidence of dark neurons in any of these rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Calcified constrictive pericarditis. Ultrasonic debridement.

A case of complete debridement of a calcified pericardium in a patient with constrictive pericarditis is reported. The use of an ultrasonic surgical aspirator facilitated disintegration of calcium without damaging the adherent epicardium and myocardium.

Aged↗
PubMed1994

Pericardectomy for chronic constrictive pericarditis: risks and outcome.

From 1970 to 1990, 71 consecutive patients (51 men and 20 women) had pericardectomy for chronic constrictive pericarditis. The mean age was 44.2 +/- 16.1 years. In the preoperative state 2.8% were in NYHA class I, 18.3% in II, 43.6% in III and 35.2% in IV. The operative approach was median sternotomy in 93% and left anterolateral thoracotomy in 7%. The early mortality rate (within 30 days after operation) was 5.6%. All four early deaths were female (P < 0.001), in the preoperative state the patients were classified as NYHA class IV (P < 0.01). These patients had a significantly higher preoperative mean right atrial pressure then survivors (21.5 +/- 8.5 mmHg vs 13.6 +/- 5.6 mmHg, P < 0.005). Follow-up was obtained for 65 patients (91.5%) and averaged 11 +/- 5.8 years (the longest period was 21.5 years). Actuarial survival at 5, 10, 15 and 20 years for all patients was 84.6% +/- 4.5%, 80.1% +/- 5.3%, 70.5% +/- 6.9% and 65.8% +/- 7.9%, respectively. In the preoperative state 10 of the 12 late deaths (83%) were classified NYHA class IV and the remaining ones class III. Of the 49 patients alive 23% belong to NYHA class I, 42% to II and 35% to III; none is in class IV. Negative predictors of survival were found to be preoperative NYHA class IV (P < 0.01), low-voltage electrocardiogram (ECG) (P < 0.01), ascites (P < 0.01), dyspnea at rest (P < 0.05) and hyperbilirubinemia (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

Heart failure after long-term supravalvular aortic constriction in rats.

BACKGROUND: Pressure overload in humans follows a chronic and progressive course, often resulting in eventual cardiac decompensation and death. Animal models of heart failure generally fail to mimic the temporal features observed in human disease often covering a major portion of the life span, and findings of short-term studies are of uncertain applicability. The purpose was to determine whether chronic pressure overload introduced gradually in young normotensive rats would lead predictably to heart failure and to characterize specific phenotype features that have been well documented in another model of heart failure. METHODS: Rats underwent banding of the ascending aorta at 7 weeks of age such that the hemodynamic load increased gradually with ontogenic growth. Two groups of hypertrophied hearts from aortic-banded rats, with and without signs of heart failure, were compared with those of control rats at a mean age of 11 months. RESULTS: Hearts of aorta-banded rats underwent a transition from stable compensated hypertrophy to heart failure that was characterized by augmented hypertrophy, depressed contractile function, elevated fibrosis, increased myocardial stiffness, and marked alterations in the expression of genes encoding contractile, regulatory, and extracellular matrix proteins. CONCLUSIONS: Gradual constriction of the rat aorta resulted in heart failure after a variable length of time (3 to 18 months). Despite differences in genotype, the ultimate phenotype associated with the transition to failure in the aorta-banded rat is nearly identical to that observed in the aged spontaneously hypertensive rat (SHR), with a few notable differences. The findings suggest that a common heart failure phenotype follows long-term pressure overload regardless of the underlying etiology.

Animals↗
PubMed2006

Immune cell involvement in dorsal root ganglia and spinal cord after chronic constriction or transection of the rat sciatic nerve.

Chronic constriction injury (CCI) of the sciatic nerve in rodents produces mechanical and thermal hyperalgesia and is a common model of neuropathic pain. Here we compare the inflammatory responses in L4/5 dorsal root ganglia (DRGs) and spinal segments after CCI with those after transection and ligation at the same site. Expression of ATF3 after one week implied that 75% of sensory and 100% of motor neurones had been axotomized after CCI. Macrophage invasion of DRGs and microglial and astrocytic activation in the spinal cord were qualitatively similar but quantitatively distinct between the lesions. The macrophage and glial reactions around neurone somata in DRGs and ventral horn were slightly greater after transection than CCI while, in the dorsal horn, microglial activation (using markers OX-42(for CD11b) and ED1(for CD68)) was greater after CCI. In DRGs, macrophages positive for OX-42(CD11b), CD4, MHC II and ED1(CD68) more frequently formed perineuronal rings beneath the glial sheath of ATF3+ medium to large neurone somata after CCI. There were more invading MHC II+ macrophages lacking OX-42(CD11b)/CD4/ED1(CD68) after transection. MHC I was expressed in DRGs and in spinal sciatic territories to a similar extent after both lesions. CD8+ T-lymphocytes aggregated to a greater extent both in DRGs and the dorsal horn after CCI, but in the ventral horn after transection. This occurred mainly by migration, additional T-cells being recruited only after CCI. Some of these were probably CD4+. It appears that inflammation of the peripheral nerve trunk after CCI triggers an adaptive immune response not seen after axotomy.

Activating Transcription Factor 3↗
PubMed2006

Heterotopic inputs facilitate poststimulus afterdischarges of spinal WDR neurons in rats with chronic nerve constriction.

Heterotopic inputs activate spinal wide dynamic range (WDR) neurons in rats with chronic constriction of one sciatic nerve (CCI rats). A possible contribution from these inputs, to long-lasting afterdischarges (ADs) of noxious evoked responses, was investigated during reversible input blockade from adjacent saphenous nerve and contralateral peripheral nerve territories. The results show significant AD reduction or suppression, indicating that heterotopic afferences contribute to mechanisms underlying prolonged ADs.

Action Potentials↗
PubMedDate not supplied

Late constrictive involvement of the pericardium in a case of previous myocarditis.

Constrictive pericarditis (CP) is a highly relevant disease clinically because pericardiectomy represents the only curative therapeutic approach. Previous cardiac surgery or mediastinal radiation may cause CP, however, infectious agents account for a substantial portion of CP. In this report, we present a patient with previous biopsy-proven myocarditis and positive seroconversion against coxsackievirus B3 without clinical evidence of acute pericardial involvement who developed CP after a prolonged period of time. This suggests that infectious particles primarily infecting the myocardium may lead to chronic inflammatory responses of the pericardium, thus causing CP even at late clinical stages. This case emphasizes the important fact that primary myocarditis may not only cause systolic ventricular impairment but may also induce diastolic dysfunction of the heart, either as restrictive cardiomyopathy or, as in this case, through inflammatory involvement of the pericardium, leading to CP.

Antibodies, Viral↗
PubMed2004

Subacute effusive-constrictive pericarditis: diagnosis by serial echocardiography.

We report the case of a 30-year-old man with acute pericarditis in whom effusive-constrictive physiology developed rapidly in less than 2 weeks. Serial echocardiography demonstrated a dramatic change in the appearance of the pericardial effusion and the pericardial space. The patient underwent pericardiectomy with symptom relief. The findings at operation included a markedly thickened and inflamed pericardium. The case highlights the role of echocardiography in the evaluation of patients with pericardial disease and the echocardiographic features that prompted early surgical intervention.

Adult↗
PubMed2005

Doppler tissue imaging improves assessment of abnormal interventricular septal and posterior wall motion in constrictive pericarditis.

We hypothesized that Doppler tissue imaging in the short axis would provide enhanced quantitative information for differentiating the pattern and extent of abnormal septal and posterior wall motion in constrictive pericarditis (CP). Using quantitative pulsed wave and color M-mode Doppler tissue imaging, we quantified the pattern of abnormal septal and posterior wall motion and studied its incremental advantage over conventional M-mode and 2-dimensional echocardiography in 40 patients with surgically proven CP. The pattern and extent of abnormalities were compared with 35 age- and sex-matched control subjects and 20 patients with abnormal septal motion of other causes. In 33 patients (82.5%) with CP, the interventricular septum showed high-velocity (>7 cm/s) early diastolic biphasic motion with or without multiple recoil waves (polyphasic diastolic septal fluttering). In the posterior wall, the early diastolic wave was normal but the late diastolic wave was reduced in 24 patients (60%) and absent in 7 (17.5%). In comparison, M-mode and 2-dimensional echocardiography identified abnormal septal or posterior wall motion in 24 patients (60%) ( P = .003). The pattern of abnormal septal motion in CP could be differentiated from abnormal septal motion of other causes in 16 patients (80%). The overall sensitivity and specificity of high-velocity polyphasic septal flutter for differentiating CP from control cases and other diseases was 82.5% and 92.7%, respectively. In CP, Doppler tissue imaging in the short axis provides unique diagnostic information and reliably differentiates CP from control cases and most other causes of abnormal septal motion.

Adult↗