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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, the cardioprotective effects of insulin-like growth factor I (IGF-I) were examined in a murine model of myocardial ischemia reperfusion (i.e., 20 min + 24 hr). IGF-I (1-10 micrograms per rat) administered 1 hr prior to ischemia significantly attenuated myocardial injury (i.e., creatine kinase loss) compared to vehicle (P < 0.001). In addition, cardiac myeloperoxidase activity, an index of neutrophil accumulation, in the ischemic area was significantly attenuated by IGF-I (P < 0.001). This protective effect of IGF-I was not observed with des-(1-3)-IGF-I. Immunohistochemical analysis of ischemic-reperfused myocardial tissue demonstrated markedly increased DNA fragmentation due to programmed cell death (i.e., apoptosis) compared to nonischemic myocardium. Furthermore, IGF-I significantly attenuated the incidence of myocyte apoptosis after myocardial ischemia and reperfusion. Therefore, IGF-I appears to be an effective agent for preserving ischemic myocardium from reperfusion injury and protects via two different mechanisms--inhibition of polymorphonuclear leukocyte-induced cardiac necrosis and inhibition of reperfusion-induced apoptosis of cardiac myocytes.
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PMID:Cardioprotective effect of insulin-like growth factor I in myocardial ischemia followed by reperfusion. 764 33

The potential effects of growth hormone (GH) deficiency in adults and the importance of GH secretion in adult life have only been recognized and documented recently. It has been suggested that GH-deficient adults may have premature mortality, abnormalities in body composition and bone density with impaired physical performance and psychological well-being, which are sometimes improved by GH replacement. It is essential, therefore, to establish reliable standards to define GH deficiency in adults. Patients with possible GH deficiency often have primary pituitary or hypothalamic disorders or have undergone surgery or radiotherapy, and thus show evidence of a failure of one of the other pituitary hormones. Several biochemical approaches have been studied to define GH deficiency in the adult and no universal consensus has yet been reached. The most widely established criterion is the peak serum GH concentration achieved during a provocative test, usually the insulin tolerance test (ITT), or following other pharmacological stimuli (e.g. glucagon, arginine, clonidine or GH-releasing factor) but, alternatively, a more physiological stimulus (such as sleep, fasting or exercise) has been used. Spontaneous circulating levels of hormones of the GH axis [24-hour integrated GH concentration, serum insulin-like growth factor I (IGF-I) or IGF-binding protein-3] have been used in the diagnosis of childhood GH deficiency. They have been tested in adults as well but seem to have a more limited role. There are several factors complicating the evaluation of these results. Basal and stimulated GH and IGF-I levels decline with age and with obesity, levels tend to be higher in females and are dependent on nutritional and physical status. The ITT potentially has some risk attached, e.g. in the presence of ischaemic heart disease, but it has proved to be safe in general when used in specialized departments. Other tests are less reliable; releasing hormone tests only assess the readily releasable stores within the pituitary and not the physiological secretory status. The 'cut-off' point for the definition of subnormal responses ideally needs to be set for each provocative test, for each age group, for each degree of obesity and for both sexes. There is considerable variability in GH assays among different laboratories, which makes it difficult to compare hormone levels. The reproducibility of provocative tests can also be variable. An advantage of the hypoglycaemia and glucagon tests is that they allow simultaneous assessment of the adrenocorticotropic hormone reserve.
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PMID:Diagnosis of growth hormone deficiency in adults. 895 Jun 17

Nested case-control sampling is designed to reduce the costs of large cohort studies. It is important to estimate the parameters of interest as efficiently as possible. We present a new maximum likelihood estimator (MLE) for nested case-control sampling in the context of Cox's proportional hazards model. The MLE is computed by the EM-algorithm, which is easy to implement in the proportional hazards setting. Standard errors are estimated by a numerical profile likelihood approach based on EM aided differentiation. The work was motivated by a nested case-control study that hypothesized that insulin-like growth factor I was associated with ischemic heart disease. The study was based on a population of 3784 Danes and 231 cases of ischemic heart disease where controls were matched on age and gender. We illustrate the use of the MLE for these data and show how the maximum likelihood framework can be used to obtain information additional to the relative risk estimates of covariates.
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PMID:Maximum likelihood estimation for Cox's regression model under nested case-control sampling. 1505 25

The adult growth hormone deficiency syndrome (AGHD) is a well-defined clinical entity characterized by decreased lean body mass and bone mineral density, increased visceral adiposity, abnormal lipid profile, decreased muscle strength and exercise endurance, and diminished quality of life. Recent studies have emphasized the increased morbidity and mortality of hypopituitary patients, and there are now data implicating growth hormone (GH) deficiency as a cause of this increase. GH replacement therapy has been shown to reverse many of these abnormalities and to be well tolerated. Meta-analyses have demonstrated that GH treatment positively affects cardiovascular risk factors, and controlled trials have shown that visceral adiposity decreases in treated patients. Improvements in bone mineral density and decreases in fracture rates have also been reported, and new studies using disease-specific questionnaires provide convincing evidence that GH greatly enhances quality of life. Epidemiologic studies indicate that higher insulin-like growth factor I (IGF-I) levels may predict risk for certain cancers, but other studies suggest that lower IGF-I levels increase risk for ischemic heart disease. However, much of the community of endocrine caregivers remains skeptical of GH treatment and, therefore, a large fraction of patients with AGHD are not treated. The accumulation of long-term treatment data will be required to provide reassurance that GH treatment is a safe and necessary form of hormone replacement therapy for patients with AGHD.
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PMID:Treatment of the adult growth hormone deficiency syndrome: directions for future research. 1603 88

Background. Elevated serum total cholesterol (TC) and triglycerides (TG) are risk factors for atherosclerosis and ischemic heart disease. Adult growth hormone deficiency (AGHD) is associated with elevated TC and TG. Many treatment protocols for AGHD use relatively high doses of growth hormone (GH) given at low frequency, which is associated with increased incidences of edema, joint pains, and carpal tunnel syndrome. We have treated > 2200 patients using a low-dose high frequency (LDHF) dosing regimen of GH which results in similar beneficial subjective responses, and fewer of the side-effects associated with the higher-dosage treatment at a substantial cost savings. Clinically, in addition to increased insulin-like growth factor I (IGF-I), we observed lower TG and TC levels and no elevation of prostate specific antigen levels in treated patients. Methods. A retrospective analysis of IGF-I, TG, TC, and PSA data from our patient population was performed to test our hypothesis that positive objective responses of IGF-I, TG, and TC occur and that elevation of PSA does not occur in response to LDHF dosing regimen of GH. The mean duration of treatment of the analyzed data ranged from 181 to 259 days. Results. The mean plasma IGF-I level rose significantly (p<.00001) to a level 37% greater than baseline with treatment. TC and TG decreased significantly (p<.001) in those patients with elevated baseline values, and did not change significantly in those with normal baseline values. PSA concentrations decreased non-significantly during treatment, and few cases of edema, joint pain, or carpal tunnel were reported. Conclusions. Treatment of AGHD using the LDHF dosing regimen of GH resulted in significant increases in IGF-I, significant reductions in TC and TG levels in patients with elevated baseline values, no increase in PSA concentrations, and fewer side effects than other dosing regimens.
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PMID:Retrospective analysis of the effects of low-dose, high frequency human growth hormone on serum lipids and prostate specific antigen. 2360 76

Clinical and experimental data in animals and patients with endstage heart failure due to dilated cardiomyopathy or ischemic heart disease suggest a beneficial role of growth factors like human recombinant growth hormone or insulin-like growth factor I. Their cardiac effects are an increase in myocardial mass and a decrease in systolic wall stress. Based on the results of animal studies and of preliminary studies in patients with dilated cardiomyopathy, double-blind and placebo-controlled studies have proven the increase in myocardial mass and a significant reduction of left ventricular wall stress, as demonstrated by magnetic resonance imaging.The risk of the additional therapy with human growth factors in this high-risk group of patients with a high mortality is justified, if this new approach becomes a possible alternative to cardiac transplantation or a bridge toward transplantation.If future randomized studies in larger patient groups with an individualized substitution therapy with growth hormone and/or IGF-I can demonstrate a beneficial effect on mortality and morbidity, this new therapeutic approach could become an attractive alternative in these high-risk patients.
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PMID:Growth hormone therapy in heart failure. 2732 Mar 10