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At least 901 records · Page 50Linked to original sources

PubMed2006

Vascular and metabolic effects of candesartan: insights from therapeutic interventions.

BACKGROUND: Effects of angiotensin II type 1 receptor blockers (ARBs) to improve endothelial dysfunction may be due to mechanisms in addition to the reduction of high blood pressure per se. Endothelial dysfunction is characterized by vascular inflammation that contributes to clinically significant atherosclerosis and by an increased tendency for thrombus formation. Hypertensive patients have impaired endothelial functions that have positive predictive power with respect to future cardiovascular events. OBJECTIVES: The present review will focus on multiple mechanisms underlying vascular and metabolic effects of ARBs that may synergize to prevent or regress atherosclerosis, onset of diabetes, and coronary heart disease. CONCLUSIONS: Angiotensin II accelerates the development of atherosclerosis by activating angiotensin II type 1 receptors that then promote superoxide anion generation and oxidative stress, leading to activation of nuclear transcription factor and endothelial dysfunction. Activation of angiotensin II type 1 receptors also stimulates increased expression of plasminogen activator inhibitor type 1 and tissue factor. Endothelial dysfunction associated with the metabolic syndrome and other insulin-resistant states is characterized by impaired insulin-stimulated production of nitric oxide from the endothelium and decreased blood flow to skeletal muscle. Increasing insulin sensitivity therefore improves endothelial function, and this may be an additional mechanism whereby ARBs decrease the incidence of coronary heart disease and the onset of diabetes. Adiponectin serves to link obesity with insulin resistance. In addition, adiponectin has anti-atherogenic properties.

Adiponectin↗

PubMed2001

Pathobiology of A/chicken/Hong Kong/220/97 (H5N1) avian influenza virus in seven gallinaceous species.

Direct bird-to-human transmission, with the production of severe respiratory disease and human mortality, is unique to the Hong Kong-origin H5N1 highly pathogenic avian influenza (HPAI) virus, which was originally isolated from a disease outbreak in chickens. The pathobiology of the A/chicken/Hong Kong/220/97 (H5N1) (HK/220) HPAI virus was investigated in chickens, turkeys, Japanese and Bobwhite quail, guinea fowl, pheasants, and partridges, where it produced 75-100% mortality within 10 days. Depression, mucoid diarrhea, and neurologic dysfunction were common clinical manifestations of disease. Grossly, the most severe and consistent lesions included splenomegaly, pulmonary edema and congestion, and hemorrhages in enteric lymphoid areas, on serosal surfaces, and in skeletal muscle. Histologic lesions were observed in multiple organs and were characterized by exudation, hemorrhage, necrosis, inflammation, or a combination of these features. The lung, heart, brain, spleen, and adrenal glands were the most consistently affected, and viral antigen was most often detected by immunohistochemistry in the parenchyma of these organs. The pathogenesis of infection with the HK/220 HPAI virus in these species was twofold. Early mortality occurring at 1-2 days postinoculation (DPI) corresponded to severe pulmonary edema and congestion and virus localization within the vascular endothelium. Mortality occurring after 2 DPI was related to systemic biochemical imbalance, multiorgan failure, or a combination of these factors. The pathobiologic features were analogous to those experimentally induced with other HPAI viruses in domestic poultry.

Adrenal Glands↗

PubMed1977

Neurologic manifestations in sarcoidosis: review of the literature, with a report of 23 cases.

Nervous system involvement by sarcoidosis has been considered rare, yet more than 400 cases have been reported. We present 23 additional cases here, including 14 with autopsies, and we review the literature. The overall frequency of neurologic involvement is 5%. Patients usually have other stigmata of sarcoidosis; however, neurologic dysfunction is frequently the presenting finding. The protean manifestations of central nervous system (CNS) involvement usually occur in the early phase of the disease, while those of peripheral nervous system and skeletal muscle involvement are characteristically seen in the chronic stages. Basal granulomatous meningitis causes most of the CNS manifestations either by infiltration or compression of adjacent structures. Steroids are the mainstay of therapy, and the overall response is quite variable. The course is also variable, being transient in some and chronic in others. The prognosis is better with peripheral than with central nervous system involvement.

Adolescent↗

PubMedDate not supplied

Drug-induced myopathies. An overview of the possible mechanisms.

Myopathy is usually a non-fatal muscle disease involving skeletal muscle weakness, tenderness and pain with the possibility of the plasma creatinine kinase elevation. There are many different types of myopathies, some of which are genetic, inflammatory, or related to endocrine dysfunction. Also, numerous drugs have been reported to possess myotoxic effect. Myopathy is included among the potential side-effects and toxicities associated with the lipid lowering agents, particularly 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. However, the precise mechanism of statin-induced muscle toxicity remains unclear. The muscle-related side-effects reported with lipid-lowering drugs are significant but quite rare (0.1%), when used in monotherapy; while the incidence of steroid-induced myopathy has varied from 7 to 60%% and chronic alcoholic myopathy seems to be common complication of alcoholism affecting approximately 50% of patients, respectively. This review focuses on the differential pathophysiological grounds of these muscular injuries induced by statins, fibrates, as well as some other agents: corticosteroids or alcohol. A wide spectrum of possible mechanisms and hypotheses including muscle enzyme defects, changes in mitochondrial function and intracellular metabolism, the influence on the cell membrane stability and drug interactions involving P-glycoprotein or cytochrome P 450 system have been presented.

Adrenal Cortex Hormones↗

PubMed2006

Oral glucosamine for 6 weeks at standard doses does not cause or worsen insulin resistance or endothelial dysfunction in lean or obese subjects.

Glucosamine is a popular nutritional supplement used to treat osteoarthritis. Intravenous administration of glucosamine causes insulin resistance and endothelial dysfunction. However, rigorous clinical studies evaluating the safety of oral glucosamine with respect to metabolic and cardiovascular pathophysiology are lacking. Therefore, we conducted a randomized, placebo-controlled, double-blind, crossover trial of oral glucosamine at standard doses (500 mg p.o. t.i.d.) in lean (n = 20) and obese (n = 20) subjects. Glucosamine or placebo treatment for 6 weeks was followed by a 1-week washout and crossover to the other arm. At baseline, and after each treatment period, insulin sensitivity was assessed by hyperinsulinemic-isoglycemic glucose clamp (SI(Clamp)) and endothelial function evaluated by brachial artery blood flow (BAF; Doppler ultrasound) and forearm skeletal muscle microvascular recruitment (ultrasound with microbubble contrast) before and during steady-state hyperinsulinemia. Plasma glucosamine pharmacokinetics after oral dosing were determined in each subject using a high-performance liquid chromatography method. As expected, at baseline, obese subjects had insulin resistance and endothelial dysfunction when compared with lean subjects (SI(Clamp) [median {25th-75th percentile}] = 4.3 [2.9-5.3] vs. 7.3 [5.7-11.3], P < 0.0001; insulin-stimulated changes in BAF [% over basal] = 12 [-6 to 84] vs. 39 [2-108], P < 0.04). When compared with placebo, glucosamine did not cause insulin resistance or endothelial dysfunction in lean subjects or significantly worsen these findings in obese subjects. The half-life of plasma glucosamine after oral dosing was approximately 150 min, with no significant changes in steady-state glucosamine levels detectable after 6 weeks of therapy. We conclude that oral glucosamine at standard doses for 6 weeks does not cause or significantly worsen insulin resistance or endothelial dysfunction in lean or obese subjects.

Administration, Oral↗

PubMed2002

Pulmonary endothelial dysfunction after cardiopulmonary bypass in neonatal pigs.

BACKGROUND: In neonatal pigs cardiopulmonary bypass (CPB) is associated with endothelial dysfunction in isolated large pulmonary arteries. It is, however, of great importance if this functional change extends to the small pulmonary resistance arteries, which are the key regulators of pulmonary flow and pressure. The aim of this study was to assess changes in pulmonary microvascular function after CPB using a clinically relevant pediatric procedure. METHODS: From three groups of neonatal pigs (CPB-, sham- and control group) pulmonary resistance arteries and systemic resistance arteries (from skeletal muscle) were isolated and mounted as ring preparations in wire myographs. Vessel diameters were less than 500 microm. Concentration-response curves were constructed for norepinephrine (NA), vasopressin (Vp), and the thromboxane A2-analog U46619, while the endothelium-dependent and -independent vasodilator functions were assessed as responses to acetylcholine and nitric oxide (NO). RESULTS: Maximum pulmonary vasodilator response to acetylcholine was attenuated after CPB compared with sham-operated and control animals (P=0.04). NO-induced relaxation, and contractile responses to NA, Vp, and U46619 were not influenced by CPB. In systemic arteries no changes in contractile or relaxant responses were seen after CPB. CONCLUSION: CPB seems to induce pulmonary endothelial dysfunction in pulmonary but not peripheral resistance arteries in neonatal piglets.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMedDate not supplied

Effects of heparin on vascular dysfunction in diabetic rats.

1. Treatment with heparin has beneficial effects in diabetic nephropathy. The occurrence of increased urinary albumin excretion in diabetic patients reflects general vascular dysfunction, including increased transcapillary permeability of macromolecules. The aim of the present study was to evaluate the effects of heparin on vascular dysfunction in diabetic rats. 2. Male Sprague-Dawley rats were used in two studies. Diabetes was induced by 65 mg/kg, i.v., streptozotocin. In one study, diabetic rats were dosed subcutaneously with different heparin fractions for 8 months and the transcapillary escape rate of albumin (TERalb) was measured in anaesthetized animals. In the other study, heparin was given for 6 weeks, followed by tissue albumin clearance measurements in awake rats. Normal and diabetic rats receiving saline served as controls. 3. Blood glucose did not differ among the diabetic groups and ranged from 22 to 26 mmol/L. The mean (+/- SD) TERalb was increased by diabetes compared with values in normal rats (17.5 +/- 3 vs 14.1 +/- 3.3%/h, respectively). Neither unfractionated nor low molecular weight heparin significantly affected this increase. [131I]-Albumin clearance was significantly increased in diabetic rats in the eye, skin and skeletal muscle tissues compared with normal rats (0.17-0.40 vs 0.1-0.23 microL plasma/g per min). Low molecular weight heparin treatment did not affect the increased organ albumin clearance. 4. In conclusion, heparin treatment does not affect diabetes-induced vascular dysfunction as expressed by increased TERalb and clearance of albumin in rats.

Animals↗

PubMed1999

Secondary abnormalities of mitochondrial DNA associated with neurodegeneration.

The central nervous system has a particularly high energy requirement, thus making it very susceptible to defects in mitochondrial function. A number of neurodegenerative diseases, in particular Parkinson's disease (PD), Huntington's disease (HD) and Friedreich's ataxia (FRDA), are associated with mitochondrial dysfunction. The identification of a mitochondrial complex-I defect in PD provides a link between toxin models of the disease, and clues to the pathogenesis of idiopathic PD. We have undertaken genomic transplantation studies involving the transfer of mitochondrial DNA (mtDNA) from PD patients with a complex-I defect to a novel nuclear background. Histochemical, immunohistochemical and functional analysis of the resulting cybrids all showed a pattern in the PD clones indicative of a mtDNA mutation. There is good evidence for the involvement of defective energy metabolism and excitotoxicity in the aetiology of HD. We, and others, have shown a severe deficiency of complex II/III confined to the striatum that mimics the toxin-induced animal models of HD. There is also a milder defect in complex IV in the caudate. The tricarboxylic acid cycle enzyme aconitase is particularly sensitive to inhibition by peroxynitrite and superoxide radicals. We have found this enzyme to be severely decreased in HD caudate, putamen and cortex in a pattern that parallels the severity of neuronal loss seen. We propose a scheme for the role of nitric oxide, free radicals and excitotoxicity in the pathogenesis of HD. FRDA is caused by an expanded GAA repeat in intron 1 of the X25 gene encoding a protein called frataxin. Frataxin is widely expressed and is a mitochondrial protein, although its function is unknown. We have found abnormal magnetic resonance spectroscopy in the skeletal muscle of FRDA patients, which parallels our biochemical findings of reduced complexes I-III in patients' heart and skeletal muscle. There is also reduced aconitase activity in these areas. Increased iron deposition was seen in patients' tissues in a pattern consistent with a mitochondrial location. The mitochondrial iron accumulation, defective respiratory chain activity and aconitase dysfunction suggest that frataxin may be involved in mitochondrial iron regulation. There is also evidence that oxidative stress contributes to cellular toxicity.

DNA, Mitochondrial↗

PubMed2005

Insulin resistance causes increased beta-cell mass but defective glucose-stimulated insulin secretion in a murine model of type 2 diabetes.

AIMS/HYPOTHESIS: Although insulin resistance induces compensatory increases in beta cell mass and function to maintain normoglycaemia, it is not clear whether insulin resistance can precipitate beta cell dysfunction and hyperglycaemia without a pre-existing beta cell susceptibility. We therefore examined the beta cell phenotype in the MKR mouse, a model in which expression of a dominant-negative IGF 1 receptor (IGF1R) in skeletal muscle leads to systemic insulin resistance and diabetes. MATERIALS AND METHODS: Circulating glucose, insulin and glucagon concentrations were measured. Insulin sensitivity, glucose tolerance and insulin release in vivo were assessed by i.p. insulin and glucose tolerance tests. Beta cell function was assessed via insulin secretion from isolated islets and the glucose gradient in the perfused pancreas. Beta cell morphology was examined via immunohistochemistry. MKR mice were fed a high-fat diet containing sucrose (HFSD) to test metabolic capacity and beta cell function. RESULTS: Insulin-resistant MKR mice developed hyperglycaemia and a loss of insulin responsiveness in vivo. Basal insulin secretion from the perfused pancreas was elevated, with no response to glucose. Despite the demand on insulin secretion, MKR mice had increased pancreatic insulin content and beta cell mass mediated through hyperplasia and hypertrophy. The HFSD worsened hyperglycaemia in MKR mice but, despite increased food intake in these mice, failed to induce the obesity observed in wild-type mice. CONCLUSIONS/INTERPRETATION: Our studies demonstrate that insulin resistance of sufficient severity can impair glucose-stimulated insulin secretion, thereby undermining beta cell compensation and leading to hyperglycaemia. Moreover, because insulin stores were intact, the secretory defects reflect an early stage of beta cell dysfunction.

Animals↗

PubMed2006

Ascorbate inhibits NADPH oxidase subunit p47phox expression in microvascular endothelial cells.

The production of reactive oxygen species (ROS) is central to the etiology of endothelial dysfunction in sepsis. Endothelial cells respond to infection by activating NADPH oxidases that are sources of intracellular ROS and potential targets for therapeutic administration of antioxidants. Ascorbate is an antioxidant that accumulates in these cells and improves capillary blood flow, vascular reactivity, arterial blood pressure, and survival in experimental sepsis. Therefore, the present study tested the hypothesis that ascorbate regulates NADPH oxidases in microvascular endothelial cells exposed to septic insult. We observed that incubation with Escherichia coli lipopolysaccharide (LPS) and interferon-gamma (IFNgamma) increased NADPH oxidase activity and expression of the enzyme subunit p47phox in mouse microvascular endothelial cells of skeletal muscle origin. Pretreatment of the cells with ascorbate prevented these increases. Polyethylene glycol-conjugated catalase and selective inhibitors of Jak2 also abrogated induction of p47phox. Exogenous hydrogen peroxide induced p47phox expression that was prevented by pretreatment of the cells with ascorbate. LPS+IFNgamma or hydrogen peroxide activated the Jak2/Stat1/IRF1 pathway and this effect was also inhibited by ascorbate. In conclusion, ascorbate blocks the stimulation by septic insult of redox-sensitive Jak2/Stat1/IRF1 signaling, p47phox expression, and NADPH oxidase activity in microvascular endothelial cells. Because endothelial NADPH oxidases produce ROS that can cause endothelial dysfunction, their inhibition by ascorbate may represent a new strategy for sepsis therapy.

Animals↗

PubMed2001

Quantitative and qualitative muscular changes after selective neurotomy.

Disfigurement of body contour, caused by excessive muscular hypertrophy, can seldom be effectively and safely corrected by lipectomy, liposuction or combined partial myomectomy. This study was conducted to obtain basic knowledge for the development of a safe and effective method of treating patients with excessive and unwelcome muscle hypertrophy. Accordingly, we developed a new experimental rat model, consisting of the peroneal nerve and its target muscles - the anterolateral crural muscle group. After severance of 1/4, 1/2, and 1/1 of the peroneal nerve, functional parameters based on gross movement and electrophysiologic data were monitored. Changes in the external circumference and weight of the anterolateral crural muscle were documented and compared with control sides. Histologic and histomorphometric parameters of the muscle were also documented. Average takeoff latency in 1/4 and 1/2 neurotomy groups was increased to 130% and 154% of the control at 3 months, and 156% and 149% of control at 6months, respectively. Similarly, average peak-to-peak compound action potentials were 72% and 59% of the control at 3months and 57% and 50% of control at 6months. No definite gait disturbances were evident in the partial neurotomy groups. Maximal circumferences of the anterolateral crural muscle group were significantly reduced to 86%, 71% and 66% of the control in the 1/4, 1/2 and 1/1 neurotomy groups at 3 months (p < 0.001), and to 74%, 68% and 64% of the control at 6 months, respectively (p < 0.001). The corresponding weights were 76%, 62%, and 50% of the control sides at 3 months, and 70%, 56%, and 48% at 6 months in 1/4, 1/2 and 1/1 neurotomy groups. Histograms drawn showing the number of muscle fibers per mm2 in cross-sections, showed a total number of 239 +/- 52 in the control group; the size of muscle fibers was mainly medium to large. The more extensive the neurotomy, the greater the was the number of small angulated muscle fibers, up to a total of 1,564 +/- 211. Although more research work and clinical trials are required, we believe that selective neurotomy has the potential of being an effective tool for reducing muscle bulk, and avoiding apparent muscular dysfunction and complications.

Animals↗

PubMed2002

Dynamics of microvascular oxygen partial pressure in contracting skeletal muscle of rats with chronic heart failure.

OBJECTIVE: This investigation tested the hypothesis that the dynamics of muscle microvascular O(2) pressure (PO(2)m, which reflects the ratio of O(2) utilization [V*O(2)] to O(2) delivery [Q*O(2)]) following the onset of contractions would be altered in chronic heart failure (CHF). METHODS: Female Sprague-Dawley rats were subjected to a myocardial infarction (MI) or a sham operation (Sham). Six to 10 weeks post Sham (n=6) or MI (n=17), phosphorescence quenching techniques were utilized to determine PO(2)m dynamics at the onset of spinotrapezius muscle contractions (1 Hz). RESULTS: MI rats were separated into groups with Moderate (n=10) and Severe (n=7) CHF based upon the degree of left ventricular (LV) dysfunction as indicated by structural abnormalities (increased right ventricle weight and lung weight normalized to body weight). LV end-diastolic pressure was elevated significantly in both CHF groups compared with Sham (Sham, 3+/-1; Moderate CHF, 9+/-2; Severe CHF, 27+/-4 mmHg, P<0.05). The PO(2)m response was modeled using time delay and exponential components to fit the PO(2)m response to the steady-state. Compared with Shams, the time constant (tau) of the primary PO(2)m response was significantly speeded in Moderate CHF (tau, Sham, 19.0+/-1.5; Moderate CHF, 13.2+/-1.9 s, P<0.05) and slowed in Severe CHF (tau, 28.2+/-3.4 s, P<0.05). Within the Severe CHF group, tau increased linearly with the product of right ventricular and lung weight (r=0.83, P<0.05). CONCLUSIONS: These results suggest that CHF alters the dynamic matching of muscle V*O(2)-to-Q*O(2) across the transition from rest to contractions and that the nature of that perturbation is dependent upon the severity of cardiac dysfunction.

Animals↗

PubMed1998

Neurotrophin-4 is up-regulated in ragged-red fibers associated with pathogenic mitochondrial DNA mutations.

Ragged-red fibers (RRFs) are found more frequently in highly oxidative type I fibers than in glycolytic type II fibers in the muscle of many patients with mitochondrial myopathies. Neurotrophin-4 (NT-4), a neuronal signaling molecule, is also expressed in skeletal muscle, predominantly in type I fibers. We found that NT-4 protein and mRNA were present in both type I and type II fibers but were up-regulated in RRFs of patients with mitochondrial encephalomyopathies; it is noteworthy that NT-4 was not up-regulated in muscle fibers from healthy aerobically trained athletes. Thus, NT-4 might represent a member of a new class of candidate molecules involved in the compensatory adjustments of muscle fibers to oxidative dysfunction, and may even play a role as a signaling molecule for mitochondrial proliferation.

Biopsy↗

PubMed1981

Temporary incomplete ischemia of the legs caused by aortic clamping in man: improvement of skeletal muscle metabolism by low molecular dextran.

Temporary infrarenal clamping of the aorta during reconstructive surgery induces incomplete ischemia of the leg muscle. After release of the clamp, severe muscle metabolic derangement with loss of high-energy phosphate compounds has been observed, indicating a dysfunction or damage of the muscle cells. In six patients operated on for occlusive aortoiliac disease, low-molecular-weight dextran (LMWD) was peroperatively administered for optimal volume loading and prevention of clotting. No heparin was used. Before, during and after the clamping period the central hemodynamics were monitored, and glycogen, glucose, lactate, pyruvate, phosphocreatine (PCr), creatine (Cr), ATP, ADP and AMP content in the thigh muscle were analyzed using enzymatic fluorometric techniques. Even though ischemia developed during the occlusion, no decline in the adenylate (ATP + ADP + AMP) or creatine (PCr + Cr) pools occurred after the clamp was released, and the energy charge of the adenine nucleotides remained unchanged. It is suggested that LMDX prevents rheologic changes impairing the microcirculation during and after the ischemic period, and thereby improves oxygenation of the muscle tissue upon reperfusion.

Adenosine Diphosphate↗

PubMed2001

Antioxidant agents have a different expression pattern in muscle fibers of patients with mitochondrial diseases.

Respiratory chain dysfunction leads to reactive oxygen species (ROS) generation with following oxidative stress and cellular damage. A histochemical and immunohistochemical study was performed on muscle biopsies from 17 patients with mitochondrial disease [chronic progressive external ophthalmoplegia (CPEO), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged red fibers (MERRF)] to evaluate the expression pattern and location of manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD) and reduced glutathione (GSH) in skeletal muscle fibers. Our data showed that: (1) MnSOD, CuZnSOD and GSH are expressed in fibers with respiratory chain deficiency; (2) the antioxidant induction is correlated with the degree of mitochondrial proliferation, but not with clinical phenotype, patients' age, duration of disease, biochemical defects or mitochondrial DNA abnormalities. In addition, we suggest that expression of MnSOD and GSH may be considered an initial, indirect sign of respiratory chain dysfunction because it is observed in the early stages of the disease.

Adult↗

PubMed2005

Antioxidants prevented oxidative injury of SR induced by Fe2+/H2O2/ascorbate system but failed to prevent Ca2+-ATPase activity decrease.

Dysfunction of sarcoplasmic reticulum (SR) Ca2+-ATPase induced by oxidative stress may be a contributing factor to the development of serious age related diseases. Incubation of sarcoplasmic reticulum (SR) vesicles of rabbit skeletal muscles with Fe2+/H2O2/ascorbate decreased the SH group content of SR approximately to 35% and Ca2+-ATPase activity to 50% of control not oxidized sample. Protein carbonyls increased twofold, lipid peroxidation was also significantly elevated. The antioxidant effects of trolox, the pyridoindole derivative stobadine and of the standardized extracts from bark of Pinus Pinaster PycnogenolR (Pyc) and from leaves of Ginkgo biloba (EGb 761) were studied on oxidatively injured SR. All antioxidants exerted preventive effects against the oxidized lipids and protein SH groups of SR vesicles. Trolox and stobadine did not influence protein carbonyl formation, while flavonoid extracts prevented carbonyl generation, probably by binding to protein. The preventive effects of the antioxidants studied on lipids and protein SH groups were however not associated with protection of Ca2+-ATPase activity. Stobadine and trolox exerted no effect on enzyme activity, Pyc and EGb 761 enhanced the inhibitory effect of Ca2+-ATPase activity in oxidatively injured SR. Concluding, under the conditions of oxidative stress induced by Fe2+/H2O2/ascorbate against SR of rabbit skeletal muscle, the agents studied demonstrated antioxidant effects yet failed to protect Ca2+-ATPase activity.

Animals↗

PubMed1980

Multiple neuromuscular abnormalities in a paranoid schizophrenic.

A broad range of skeletal muscle fiber abnormalities has been reported previously in muscle biopsy specimens from psychotic patients. In our experience, individual patients manifest only a few types of lesions; but we now have studied a paranoid schizophrenic patient whose skeletal muscle fibers show virtually the entire range of morphologic abnormalities. In addition to the morphologic abnormalities of skeletal muscle fibers, we also noted increased branching of subterminal motor nerves with enlarged endplates and chronic elevations of serum creatine phosphokinase activity. Despite this, the patient had minimal clinical evidence of neuromuscular dysfunction. The variety of types of neuromuscular dysfunctions found in this patient suggests their etiology may be related.

Adult↗

PubMed2000

Cardiovascular profile of the calcium sensitizer EMD 57033 in open-chest anaesthetized pigs with regionally stunned myocardium.

1. Ca(2+) sensitizers enhance systolic function, but may impair relaxation in vitro; these effects may differ in stunned and normal myocardium. We therefore studied the effect of EMD 57033 on systolic and diastolic function of normal and stunned porcine myocardium in vivo. 2. Myocardial stunning by 15 min coronary occlusion and 30 min reperfusion abolished systolic shortening (SS) (baseline 13+/-1%) and decreased end-systolic elastance (E(es)) from 67+/-7 to 47+/-5 mmHg mm(-1) (both P<0.05). Maximum rate of fall of myocardial elastance (dE/dt(min)) decreased from -850+/-100 to -320+/-30 mmHg mm(-1) s(-1), while the time constant tau(e) of the decay of elastance increased from 58+/-3 to 68+/-6 ms (both P<0.05). End-diastolic elastance (E(ed)) was unchanged although the zero pressure intercept (L(0,ed)) had increased. 3. In the stunned region, EMD 57033 (0.2 mg kg(-1) min(-1) for 60 min, i.v., n=7) increased SS to 19+/-2%, E(es) to 287+/-40 mmHg mm(-1), dE/dt(min) to -3630+/-640 mmHg mm(-1) s(-1) and decreased tau(e) to 50+/-3 ms, while E(ed) remained unchanged. In the normal region, 4. EMD 57033 increased SS from 14+/-2 to 18+/-3%, E(es) from 59+/-4 to 263+/-23 mmHg mm(-1), dE/dt(min) from -480+/-70 to -2280+/-700 mmHg mm(-1) s(-1) and decreased tau(e) from 91+/-12 to 61+/-3 ms (all P<0.05), while E(ed) remained unchanged. These responses were minimally affected by adrenoceptor blockade (n=7). Vehicle (n=7) had no effect on either region. EMD 57033 increased cardiac output (up to 27+/-8%) and LVdP/dt(max) (86+/-19%). Mean aortic pressure decreased (19+/-7%) due to systemic vasodilation that was not amenable to blockade of adrenoceptors or NO synthesis. 5. In conclusion, EMD 57033 restored systolic and diastolic function of stunned myocardium, and produced similar improvements in systolic and diastolic function in normal myocardium.

Anesthesia↗