Intravenous catecholamine administration affects mouse intestinal lymphocyte number and apoptosis

The purposes of this study were to determine plasma and intestinal epinephrine (E) and norepinephrine (NE) concentrations in mice after exercise stress and, the effect of intravenous injection of E and NE (at concentrations during exercise) on viability of intestinal lymphocytes (IL). Exhaustive exercise significantly elevated plasma E and NE, and intestinal E, compared with sedentary animals. Twenty-four hours after intravenous NE administration, IL counts were higher (p<0.001) and % apoptotic IL were lower (p<0.001) than saline conditions. E resulted in fewer apoptotic IL at 24 h compared to saline controls. E and NE differentially influence IL numbers at 24 h after injection although both result in fewer % apoptotic IL relative to mice given saline only.

β-adrenergic receptor blockade during exercise decreases intestinal lymphocyte apoptosis but not cell loss in mice

Catecholamines induce apoptosis in various lymphoid populations. This process can occur with both α- and β-adrenoreceptors. Heavy exercise increases plasma catecholamine concentrations, and is also a cause of lymphocyte apoptosis, a possible explanation for postexercise lymphocytopenia. The purpose of this study was to examine the effects of adrenoreceptor antagonism on exercise-induced decreases and apoptosis of intestinal lymphocytes. Mice received an intraperitoneal injection of phentolamine (a nonselective α-blocker), nadolol (a nonselective β-blocker), or saline (vehicle) prior to an exhaustive bout of exercise. Total intestinal lymphocyte numbers, percent and number of CD3+ lymphocytes, and cell viability were assessed. Neither α- nor β-antagonism prevented exercise-induced cell loss in the intestine; however, pretreatment with nadolol significantly reduced the number of apoptotic and necrotic cells. Phentolamine administration appeared to increase the incidence of cell death among intestinal lymphocytes. Both drugs decreased the percentage of CD3+ intestinal lymphocytes. Our study suggests that catecholamines are not responsible for postexercise lymphocytopenia, but β-adrenoceptor blockade may confer protection against exercise-induced apoptosis of intestinal lymphocytes.Key words: catecholamines, exhaustive exercise, apoptosis, intestinal lymphocytes, rodents.

Age-adjusted outcomes in traumatic flail chest injuries in the elderly

Severe chest trauma does not independently predict poor outcome in elderly patients. We chose a specific injury, flail chest, to determine whether age factored into outcome of these patients. A retrospective chart review of all trauma admissions to our Level I trauma center between January 1994 and January 1998 sustaining flail chest was undertaken. Sixty-eight patients were identified, but ten patients were excluded because of death on arrival. Fifty-eight patients were included in the study and separated into groups. The first group comprised those under the age of 55 (n = 32) and the second comprised those over age 55 (n = 26). Parameters evaluated were age, Injury Severity Score (ISS), neurologic injury, the need for mechanical ventilation, need for tracheostomy, length of stay, and death. Statistical analysis was performed with Wilcoxon t test, chi2, and logistic regression where appropriate. A 95 per cent confidence interval was sought as determinant of significance. Of the 58 surviving patients analyzed there was no significant difference between the groups regarding ISS, length of stay, days on the ventilator, head injury, tracheostomy, or development of pneumonia or adult respiratory distress syndrome. The likelihood of death was shown to increase by 132 per cent for every 10 years starting at the second decade and continuing to the eighth decade of life. The likelihood of death also increased by 30 per cent for each unit increase in ISS. The likelihood of death decreased by 23 per cent for every day survived in the hospital. Blunt chest trauma directly impacts respiratory mechanics. Elderly patients are more likely to have comorbid conditions and less likely to tolerate traumatic respiratory compromise. Age (and its effects on the body) is the strongest predictor of outcome with flail chest and is associated with an increased mortality (P < or = 0.05).

Transmyocardial laser revascularization: current status

Transmyocardial laser revascularization (TMLR) has been widely evaluated for treatment of the ischemic myocardium either in conjunction with coronary artery bypass grafting or as sole therapy. Clinically, it has shown significant improvement for angina symptoms, but the mechanism by which this modality works is unknown at this time. The original premise on which transmyocardial revascularization was established depended on its ability to essentially generate channels that would directly carry blood from the ventricle into the ischemic myocardium. This theory, however, has not been substantiated, so other mechanisms have been postulated. This article gives a historical perspective on the advent of transmyocardial revascularization and the many animal and human studies that have paved the way for its clinical use. Current controversies are examined, along with the new advances in laser technology and where the future of TMLR is headed.

Effect of tumor bulk on local control and survival of patients with T1 glottic cancer

PURPOSE

To evaluate the effect of tumor bulk in relation to various tumor-related prognostic factors and treatment-related variables on local control and survival of patients with T1 N0 M0 squamous cell carcinoma of the glottis.

MATERIALS AND METHODS

In 114 patients with T1 squamous cell carcinoma of the glottic larynx who were irradiated with curative intent, we determined the effect of tumor bulk in relation to mucosal extent (stage and anterior commissure involvement), histologic differentiation and various radiation factors, especially overall treatment time on local control and survival. Tumors were classified retrospectively as small surface lesions or bulky tumors. Seventy-seven patients had small lesions and 37 had bulky tumors. The anterior commissure was involved with cancer in 43 patients. The overall duration of irradiation ranged from 39 to 64 days. The median follow-up time was 6 years (range 5-24 years).

RESULTS

The 5-year actuarial local control rate for all patients was 82% after radiotherapy and 92% after salvage laryngectomy. On univariate analysis, bulky tumors and tumors involving the anterior commissure showed an adverse effect on local control, whereas the overall duration of irradiation had a borderline significance. The actuarial local control rate was 91% for small tumors and 58% for bulky tumors (P = 0.0002), 88% when the anterior commissure was not involved and 67% when the anterior commissure was involved (P = 0.01) and 89% when radiation was given in less than 50 days and 73% when irradiation exceeded 50 days (P = 0.06). On multivariate analysis. tumor bulk was the only significant factor that affected local control (P = 0.02). The 5-year actuarial survival for all patients was 73% and the disease-free survival was 92%.

CONCLUSION

This study shows that tumor bulk has a highly significant effect on the radiation control of T1 glottic cancer. Patients who had bulky tumors had lower local control and disease-free survival rates than those patients who had small tumors.

Pathologic changes in a long-term heterotopic heart transplant survivor

This report concerns the pathologic findings observed at autopsy in a 10-year-old heterotopic heart transplant under cyclosporine treatment. The allograft showed a diffuse multivessel atherosclerotic disease whereas in the recipient heart coronary arteries and aorta were focally affected by atherosclerosis. The proliferating cell nuclear antigen had significantly increased expression in the allograft vessels in comparison with the recipient.

Effect of magnetic resonance imaging on implantable eyelid weights

Implanted upper eyelid gold weights are used to prevent corneal injury in patients with facial nerve paralysis. Some of these individuals require postoperative radiographic surveillance for recurrent lateral skull base disease. Magnetic resonance imaging (MRI) provides the most accurate radiologic assessment; however, there is concern about the safety of performing MRI in patients with any metallic implant. Potential risks include local tissue heating and implant migration. Gold weights of 0.8 and 1.4 g were placed in an open chamber and were exposed to a magnetic field of 1.5 T. There was no measurable motion or displacement of the weights. The results were similar in 6 rats in which gold weights were subcutaneously implanted. Additionally, histologic examination of the implant sites revealed no adverse tissue effects attributable to MRI-generated heating of the implants. When carbon steel implants in the rat model were subjected to the magnetic field, there was no displacement of the implants and no adverse tissue effects were noted, despite the fact that a carbon steel implant in an open chamber demonstrated significant migration. The absence of motion of the gold weight implants combined with the lack of adverse tissue effects suggests the relative safety of performing MRI in patients with previously placed gold weights as upper eyelid implants.

[Is coronary angioplasty less costly than aortocoronary bypass?]

We retrospectively compared the cost-benefit ratio of coronary bypass grafting (CABG) and percutaneous coronary angioplasty (PTCA). Data were obtained on 40 CABG's and 40 PTCA's patients treated from 15/2/86 to 15/9/86. All patients had at last 1-year follow-up. PTCA and CABG groups had similar baseline clinical and angiographic criteria. We analyzed the following cost components: real estate, biomedical products, drugs, hospital charges, medical fees, cardiac and non-cardiac tests. Total cost of CABG exceeds that of PTCA by a factor of 1.64: 15,095,000 vs 9,201,346 Italian liras (ILit). Taking into account early and late medical and surgical complications, the factor decreases to 1.39: 15,746,500 vs 11,323,000 ILit. After 1 year of follow-up the factor decreases to 1.18: 16,613,500 vs 14,027,500 ILit. Our data show that the initial savings were reduced when complications and follow-up are considered, but PTCA's patients had shorter hospitalization, earlier return to work, lower psychosocial stress.

3,4-Methylenedioxymethamphetamine ("ecstasy") selectively destroys brain serotonin terminals in rhesus monkeys

3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy"), an amphetamine analog, is a "designer drug" which is being increasingly abused. The potential neurotoxic hazard of MDMA in humans was assessed by examining the effects of repeated systemic administration of MDMA on selected neurochemical and behavioral measures in rhesus monkeys. In the first study, MDMA (2.5 or 10 mg/kg twice daily for 4 days) produced selective and significant neurochemical decreases in cerebrospinal fluid (CSF) concentrations of 5-hydroxyindoleacetic acid (5-HIAA) and brain concentrations of serotonin and 5-HIAA. At the high dose of MDMA, a selective decrease in serotonin uptake sites (reflecting destruction of brain serotonin terminals) was observed. To determine if these changes after high dose MDMA were pharmacologic or truly neurotoxic, in a subsequent study monkeys were treated with MDMA (10 mg/kg twice daily for 4 days) and then monitored for 14 weeks. Throughout this period, CSF 5-HIAA was decreased in MDMA-treated animals but not in saline-injected controls. At the end of this period, significant decreases in the concentration of serotonin, 5-HIAA and serotonin uptake sites were observed in cerebral cortex and striatum but not in hypothalamus or spinal cord. In contrast to these widespread alterations in serotonin markers, comparable noradrenergic and dopaminergic measures in CSF and brain appeared generally unaffected. These data demonstrating potent and selective effects of MDMA on various brain serotonin parameters in rhesus monkeys suggest that the drug may produce similar effects in humans.

Changes in mu opiate receptors following inescapable shock

Rats exposed to inescapable shock exhibit profound hypoalgesia. Pharmacological evidence has suggested that changes in endogenous opiate activity may be responsible for the hypoalgesic response. We measured the binding of [3H]DAGO, a selective mu-opiate receptor agonist, in brains of rats exposed to no shock, inescapable shock, or escapable shock. Binding of [3H]DAGO in the midbrains of rats in the inescapable shock group was decreased relative to the other two groups. The decrease in binding appeared to result from a decrease in number of mu-receptors and not a change in affinity. These results support the hypothesis that inescapable shock produces long-term changes in endogenous opiate systems.

[Myocardial scintigraphy with thallium-201 in the evaluation of aortocoronary bypass patients]

We have compared the results of 201-Thallium scintigraphy (201 TI Sc) and those of coronary angiography in 48 patients (Pts) at a mean time of 13 months after a coronary artery by-pass grafting operation (CABG). Forty-six pts were males and 2 females, with a mean age of 52 years (range 37-66). Eighteen pts (37%) had had a myocardial infarction (MI) before the operation, 4 (8%) had a perioperative and 3 (6%) a postoperative MI. Nineteen pts (40%) had angina, 9 (19%) atypical chest pain, 6 (12%) shortness of breath or easy fatigability and 14 (29%) had no symptoms. The overall CABG patency was 74% (left anterior descending: 73%, left circumflex: 71%, right coronary artery: 80%). The 201 TI was injected at peak exercise and its myocardial uptake was recorded immediately and after four hours at rest. The 201 TI Sc has shown a sensibility (SN), specificity (SP), positive predictive (PV-pos) and negative predictive value (PV-neg) of 86, 82, 64 and 94% respectively, compared to coronary angiography. In the single patient evaluation the 201 TI Sc has shown a SN, SP, PV-pos, PV-neg of 95, 85, 82 and 96% respectively versus 90, 82, 78 and 92% of the standard exercise test associated with a positive history for 1) residual angina and 2) peri or postoperative MI. The 201 TI Sc has not shown to be significantly superior to standard exercise testing and history in the evaluation of graft patency. However it allows a topographic localization of the disease which is not feasible with the latter techniques. The 201 TI Sc can better predict the patency rather than the occlusion of the grafts because there is a high number of false positives due to residual ungrafted native disease in the territory of a good functioning graft. The 201 TI scintigraphy can give a functional evaluation of borderline grafts stenoses beside the pure anatomic definition of angiography thanks to its capability to qualitatively assess the regional myocardial blood flow during stress.

Long-term follow-up after a controlled randomized post-myocardial infarction rehabilitation programme: effects on morbidity and mortality

Prognosis during 4.5 years of follow-up after myocardial infarction (MI) in 2 groups of patients 25 to 65 years of age was related to physical rehabilitation and usual risk factors. We randomized 167 patients to a rehabilitation (R) group and a control (C) group (84 and 83 patients respectively). At the end of the training period, the R group had a significantly higher work capacity, a higher double product reached during the stress test and lower triglycerides. During the 55 months of follow-up after the physical training or the equivalent spontaneous activity, we observed the prevalence of risk factors and of cardiac events such as angina, new MI, unstable angina, coronary bypass grafting and cardiac death. Survival rate was 92.6% in the R group and 93.7% in the C group. There was no relationship between serum cholesterol levels, tobacco smoking, and blood pressure and mortality and morbidity after the infarction. R patients were more symptom-free (44% against 30%), and had almost the same number of episodes of unstable angina and of cardiac death. 6.1% of the R group and 11.2% of the C group developed a new myocardial infarction. As in previous randomized studies we did not reach statistical significance for long-term benefit, perhaps because of the low sample size. However, our study confirmed a favorable tendency in terms of symptoms and the self confidence of the R patients.

Gonadal steroids deficiency and prolactin response to a met-enkephalin analog in man

The aim of this study was to ascertain whether there is a correlation between gonadal steroids and opioid control of prolactin (PRL) secretion. Four castrated men, aged 18 to 24 years were submitted to intravenous injection of 250 ug of a met-enkephalin analog (D-Ala2-Mephe4-Met-(o)-ol-Enkephalin, FK 33824) (DAMME). In normal men DAMME injection was also performed on the 6th day after treatment with clomiphene citrate (CC) (200 mg/day for 5 days), a specific nonsteroidal estrogen receptor blocker. In castrated men and in normal men after CC treatment, there was a lower PRL response to DAMME than in controls (P less than 0.0005). These results suggest that gonadal steroid deficiency seems to cause a change in the opioid system and/or dopaminergic control of prolactin secretion.

The prognostic significance of clinical history, exercise testing and ambulatory electrocardiography in patients with uncomplicated myocardial infarction

The prognostic value of early clinical history, exercise testing and ambulatory electrocardiography was assessed in 263 men (mean age 50 years) recovering from an uncomplicated myocardial infarction (MI). During a mean follow-up period of 31 months, 11 patients died of cardiac causes, 22 developed a non fatal recurrent MI, 16 unstable angina (UA) and 16 underwent coronary artery bypass surgery. The appearance at the exercise stress test of an ischemic S-T segment depression of 0.2 mV or greater (P less than 0.001) as well as the achievement of a work load of 360 Kg-m/m' or less (P less than 0.01) and of a rate-pressure product of 200 Units or less (P less than 0.01), were found to be predictive of the future development of UA, but neither of cardiac death nor of non fatal recurrent MI. The ischemic response was also seen to be predictive of cardiac death (P less than 0.05). S-T segment depression of 0.1 mV or greater, angina and ventricular ectopic activity during the stress test and clinical history were not of predictive value. Complex ventricular ectopic activity (multiform extrasystoles, couplets and ventricular tachycardia) recorded during 24 hour ambulatory electrocardiogram was seen to be predictive of death and non fatal MI. Whereas some parameters such as the ejection fraction and the extension of coronary artery disease are generally accepted as good predictors for cardiac events, others, such as those derived from exercise testing, history and ambulatory electrocardiography may change their predictive value from one survey to another. These discrepancies are due to differences in patient characteristics, in methodology and in medical management.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of gonadal steroids on the dopamine inhibitory effect on gonadotropin release in men

The aim of this study was to ascertain whether an interrelationship exists between gonadal steroids and the inhibition of gonadotropin secretion by dopamine. The effect of dopamine infusion (4 micrograms/kg/minute intravenously) on gonadotropin plasma levels in four castrated men (18 to 23 years of age) and in four age-matched normal men was studied. Normal subjects were studied before and after treatment with a specific nonsteroidal estrogen receptor antagonist, CC. LH plasma levels in normal subjects receiving CC had a maximum decrease percentage and a net decrease significantly greater (P less than 0.005 and P less than 0.012, respectively) than those before CC treatment. In castrated subjects the maximum decrease percentage was significantly greater (P less than 0.005) than in control subjects, but it did not show any difference from that of normal subjects receiving CC. In none of the group were significant changes in FSH concentration observed. The findings suggest that whenever there is a gonadal steroid deficiency, dopamine infusion causes an increased sensitivity to LH inhibition. This may be due to a lower endogenous dopaminergic influence on LH secretion.

Gonadal steroids and opioid control of gonadotropin secretion in man

The aim of this study was to ascertain whether there was an interrelationship between gonadal steroids and endogenous opioid peptides. The effects of naloxone (20 mg, intravenously) and of a met-enkephalin analog (DAMME) (250 micrograms, intravenously) on gonadotropin secretion in three castrated men (18 to 23 years of age) and in five age-matched normal men were studied. Normal subjects were studied before and after treatment with a specific nonsteroidal estrogen receptor antagonist, clomiphene. Naloxone caused a significant increase in luteinizing hormone (LH) (P less than 0.05); in these subjects, clomiphene treatment significantly increased LH and follicle-stimulating hormone plasma levels but totally suppressed the naloxone-induced rise in LH. In castrated men, naloxone failed to increase plasma LH levels. However, DAMME significantly reduced plasma LH levels in normal, in castrated, and in clomiphene-treated normal subjects. The results demonstrate that in castrated subjects who lack gonadal steroids and in normal subjects with blocked estrogen receptors there is a reduced opioid inhibitory tone on gonadotropin secretion. The effect of DAMME on gonadotropin secretion, however, is not influenced by the gonadal steroid environment.