Search PubMed⌕ Search

Biomedical subjects

S Marra

Publications and source records attributed to S Marra.

At least 19 recordsLinked to original sources
PubMed2005

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.

Animals↗
PubMed2005

Polyethylene glycol but not mifepristone prevents intestinal lymphocyte loss following treadmill exercise in mice.

UNLABELLED: Circulating lymphocyte numbers decrease following intense physical activity, possibly due to exercise-induced apoptosis. Increased reactive oxygen species (ROS) and glucocorticoids (GC) following exercise contribute to lymphocyte apoptosis. Intestinal lymphocyte (IL) numbers also decrease following exercise. AIM: The purpose of this study was to determine the contribution of GC to exercise-induced IL loss. METHODS: Female C57BL/6 mice (n = 178) were randomized to five drug conditions: (1) single injection of the glucocorticoid receptor antagonist mifepristone (MIF) solubilized in polyethylene glycol (PEG); (2) three injections of MIF (repeated MIF) PEG; (3) single injection of PEG (PEG); (4) three injections of PEG (repeated PEG); or (5) repeated injections of saline (SAL). Within each drug group mice were further randomized to exercise conditions: (1) control condition (non-exercised); (2) treadmill running with sacrifice immediately following the exercise; or (3) treadmill running with sacrifice 24 h after completion of the exercise. RESULTS: There was a significant exercise effect, across all T lymphocyte subsets, in SAL (P < 0.01), PEG (P < 0.01) and MIF (P < 0.01) treated mice but not in mice given repeated PEG or repeated MIF exposure. The exercise effect was due to reduced IL numbers 24 h post-exercise compared with non-exercised controls. CONCLUSION: These results suggest that GC are not directly responsible for IL cell loss following exercise. Repeated exposure to PEG may confer protection in the gastrointestinal tract from exercise-induced lymphocyte depletion. Because PEG inhibits ROS generation in experimental cell injury, the mechanisms for IL loss after exercise may involve oxidative stress.

Animals↗
PubMed2004

Beta-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 alpha- and beta-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 alpha-blocker), nadolol (a nonselective beta-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 alpha- nor beta-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 beta-adrenoceptor blockade may confer protection against exercise-induced apoptosis of intestinal lymphocytes.

Adrenergic Antagonists↗
PubMed2000

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).

Adolescent↗
PubMed1998

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.

Adult↗
PubMed1995

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.

Animals↗
PubMed1995

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.

Coronary Disease↗
PubMed1991

[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.

Angioplasty, Balloon, Coronary↗
PubMed1989

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.

Animals↗
PubMed1989

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.

3,4-Methylenedioxyamphetamine↗
PubMed1987

[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.

Adult↗
PubMed1985

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.

Adolescent↗