The aim of the study was to investigate the effects of regularly eating a moderate amount of sucrose (30 g/day) in 12 type 1 (insulin-dependent, IDDM) diabetic outpatients in fair blood glucose and lipid control. Two diets, each lasting two months, were compared in a randomized cross-over study. The former was a high-carbohydrate high-fiber diet for diabetic patients with Italian alimentary habits, the latter had the same composition except that 30 g of sucrose replaced 30 g of complex carbohydrates with high glycemic index (bread). The two diets contained equal amounts of carbohydrates, proteins and lipids; the only difference being the contribution of oligosaccharides to total carbohydrates (22% vs 34%) and cholesterol amount. During the control diet, glycosylated hemoglobin was substantially unchanged in both control and sucrose diet periods (control diet: 6.91 +/- 0.29 (SE) vs 6.80 +/- 0.25%; sucrose diet: 6.75 +/- 0.31 vs 6.91 +/- 0.36%). This was true also for fructosamine (control diet: 3.92 +/- 0.21 vs 3.76 +/- 0.18%; sucrose 3.50 +/- 0.14 vs 3.64 +/- 0.20 mmol/l). Circulating blood lipid levels, body weight and daily insulin dose did not show any significant variations during the study. Moderate amounts of sucrose may be allowed to IDDM patients with Italian alimentary habits without worsening diabetic control.

Adolescent↗

PubMedDate not supplied

Cardiovascular adjustments to exercise: hemodynamics and mechanisms.

The integrated response to severe exercise involves fourfold to fivefold increases in cardiac output, which are due primarily to increases in cardiac rate and to a lesser extent to augmentation of stroke volume. The increase in stroke volume is partly due to an increase in end-diastolic cardiac size (Frank-Starling mechanism) and secondarily due to a reduction in end-systolic cardiac size. The full role of the Frank-Starling mechanism is masked by the concomitant tachycardia. The reduction in end-systolic dimensions can be related to increased contractility, mediated by beta adrenergic stimulation. Beta adrenergic blockade prevents the inotropic response, the decrease in end-systolic dimensions, and approximately 50% of the tachycardia of exercise. The enhanced cardiac output is distributed preferentially to the exercising muscles including the heart. Blood flow to the heart increases fourfold to fivefold as well, mainly reflecting the augmented metabolic requirements of the myocardium due to near maximal increases in cardiac rate and contractility. Blood flow to the inactive viscera (e.g., kidney and gastrointestinal tract) is maintained during severe exercise in the normal dog. It is suggested that local autoregulatory mechanisms are responsible for maintained visceral flow in the face of neural and hormonal autonomic drive, which acts to constrict renal and mesenteric vessels and to reduce blood flow. However, in the presence of circulatory impairment, where oxygen delivery to the exercising muscles is impaired as occurs to complete heart block where normal heart rate increases during exercise are prevented, or in congestive right heart failure, where normal stroke volume increases during exercise are impaired, or in the presence of severe anemia, where oxygen-carrying capacity of the blood is limited, visceral blood flows are reduced drastically and blood is diverted to the exercising musculature. Thus,, visceral flow is normally maintained during severe exercise as long as all other compensatory mechanisms remain intact. However, when any other compensatory mechanism is disrupted (even the elimination of splenic reserve in the dog), reduction and diversion of visceral flow occur.

Adaptation, Physiological↗

PubMedDate not supplied

Adaptational changes in the neural control of cardiorespiratory function in a confined environment: the CNEC#3 experiment.

The goal of the study was to characterize the changes in neurovegetative control of the circulation, attending the presumed physiological and psychological stress originated by the isolation and confinement typical of the living condition of space stations, as simulated in a ground based unit, using time and frequency domain analysis. As a secondary goal we sought to verify the implementation of real time data acquisition, for off line spectral analysis of R-R interval, systolic arterial pressure (by Finapres) and respiration (by PVF2 piezoelectric sensors). We addressed the cardiorespiratory and neurovegetative responses to standardized, simple stressors (active standing, dynamic and static handgrip) on the EXEMSI 92 crew, before, during and after the isolation period. On average the appropriate excitatory responses (to stand, dynamic and static handgrip) were elicited also in isolation and confinement. Active standing and small masses muscular exercises are easy to be performed in a confined and isolated environment and provide a valuable tool for investigating the adaptational changes in neural control mechanisms. The possibility there exists of using this time and frequency domain approach to monitor the level of performance and well being of the space crew in (quasi) real time.

Adaptation, Physiological↗

PubMedDate not supplied

Cardiovascular reflexes mediated by sympathetic afferent fibers.

In this paper the experimental evidence supporting the hypothesis that excitatory sympathetic reflexes may participate in the tonic control of the cardiovascular system is discussed. Positive feedback pressor sympathetic reflexes can be obtained with physiological distensions of the descending thoracic aorta in conscious dogs with all nerves intact in absence of any pain reaction. These excitatory reflexes interact with supraspinal regulatory mechanisms, inhibitory in nature. A massive excitation of cardiac sympathetic afferents, produced by intracoronary injections of bradykinin, also elicits a pressor reflex, without pain reactions. In the absence of anesthesia and recent surgery, the cardiovascular excitatory reflexes, subserved by sympathetic afferent fibers, can easily prevail. We suggest that negative and positive feedback mechanisms interact continuously to achieve the most adequate neural cardiovascular control.

Animals↗

PubMedDate not supplied

A controlled study of the effects of mental relaxation on autonomic excitatory responses in healthy subjects.

OBJECTIVE: Circumstantial evidence indicates that, in the presence of a suitable substratum, sudden, behaviorally induced increases in sympathetic drive to the cardiovascular system might play an important physiopathological role in various conditions, ranging from arterial hypertension to sudden coronary death. Accordingly, it might be useful to study the effects of behavioral interventions, such as mental relaxation, that might be capable of blunting excitatory autonomic responses. It would also be preferable to study healthy subjects in whom autonomic control is not modified by the presence of disease, and to use noninvasive approaches to minimize the possible emotional impact produced by invasive recordings. METHODS: We examined healthy subjects who were either subjected to relaxation training (N = 13) or sham relaxation (N = 12). An additional group, treated with beta-adrenergic blockade (N = 12), was also examined. Spectral and cross-spectral analysis of RR interval and systolic arterial pressure (SAP) variabilities provided quantitative markers of sympathovagal balance modulating the sinoatrial (SA) node, of sympathetic vasomotor modulation, and of the gain of the arterial pressure/heart period baroreflex (index alpha). Subjects were studied at rest, during standing, and during mental arithmetic. RESULTS: Data indicate that both beta-adrenergic blockade and relaxation training significantly blunted the excitatory autonomic responses to standing and to mental arithmetic. Indices of sympathetic modulation also seemed reduced by beta blockade at rest. No changes were observed with sham training. CONCLUSIONS: Frequency domain analysis of cardiovascular variabilities, using a totally noninvasive approach, indicates that relaxation training significantly blunts the excitatory autonomic changes produced by standardized behavioral laboratory stimuli.

Adrenergic beta-Antagonists↗

PubMedDate not supplied

Mapping pathological (99m)Tc-d,l-hexamethylpropylene amine oxime uptake in Alzheimer's disease and frontal lobe dementia with SPECT.

Seventeen patients with probable Alzheimer's disease (AD), 7 patients with frontal lobe dementia (FLD) and 19 control subjects (NOR) were examined by (99m)Tc-d,l- hexamethylpropylene amine oxime ((99m)Tc-HMPAO) SPECT. Images were standardised in the same 3D space and averaged within each group. After normalisation, the three sets of images were analysed in all cerebral lobes, hippocampus, thalamus and basal ganglia. In AD, the (99m)Tc-HMPAO uptake values were significantly reduced, as compared to NOR, in the parietal, temporal and insular lobes. In patients with FLD, the uptake was altered in all lobes with the exception of the parietal lobe. The uptake in the nucleus caudatus decreased significantly in both AD and FLD as compared to NOR. The uptake in the anterior cingulate cortex was significantly reduced in FLD. Subtraction images highlighted all significantly decreased areas. In conclusion, standardising SPECT in a common space and subtracting data from a control group improves the visual interpretation of images. In this study, the typical temporo-parietal and fronto-parietal (99m)Tc-HMPAO uptake reductions were found in AD and FLD, respectively. The uptake in the nucleus caudatus was found to decrease significantly in AD and FLD and the one in the anterior cingulate cortex was reduced in FLD.

Aged↗

PubMedDate not supplied

Epirubicin, cisplatin and continuous infusion 5-fluorouracil (ECF) in locally advanced or metastatic gastric cancer: a single institution experience.

AIMS AND BACKGROUND: The role of chemotherapy in locally advanced or metastatic gastric cancer has been controversial, but chemotherapy has recently been shown to relieve tumor-related symptoms, improve quality of life and prolong survival when compared with best supportive care. Furthermore, palliative chemotherapy is also cost-effective. "Second-generation" combination chemotherapy regimens were developed in the 1980s with high activity in advanced or metastatic gastric cancer (EAP, FAMTX, PELF, ECF). In randomized studies, EAP demonstrated no difference in activity but a significantly higher overall toxicity and toxic death rate than FAMTX, and the ECF (epirubicin, cisplatin, 5-fluorouracil) regimen gave a survival and response advantage, tolerable toxicity, better quality of life and was more cost-effective than FAMTX. METHODS: Sixty patients with locally advanced or metastatic gastric cancer were treated with the ECF regimen (21 weeks of 5-fluorouracil given by continuous infusion through a central line at 200 mg/m2 for 24-hr combined with cisplatin at 60 mg/M2 iv and epirubicin at 50 mg/M2 iv beginning on day 1 and repeated every 3 weeks for 8 courses). There were 42 males and 18 females, with a median age of 64 years (range, 40-74). The median performance status was 1. The histologic type was adenocarcinoma in 44 patients and undifferentiated carcinoma in 16 (27%). Three patients had locally advanced disease (5%) and 57 had metastatic disease (95%). Seven patients (12%) had received prior chemotherapy for advanced disease. RESULTS: All patients were assessable for toxicity and 55 for response (5 had insufficient treatment). Toxicity was mild or moderate, and there was no toxic death. Incidence of WHO toxicity > or = 2 was nausea and vomiting in 3%, mucositis in 3%, leukopenia in 7%, anemia in 3%, and thrombocytopenia in 2%. Port-a-Cath toxicity was thrombosis in 4, dislocation in 2 and infection in 3 patients. Seven complete responses and 13 partial responses (overall response rate, 36%) were achieved, with a response rate of 39% in untreated and 17% in pretreated patients. Nine patients (16%) had stable disease and 26 (47%) progressive disease. Most patients felt symptomatically improved on ECF. CONCLUSIONS: Our study confirms that the ECF regimen has a favorable pattern of toxicity and is feasible on an outpatient basis. However, it did not confirm the high response rate reported in other phase II trials.

Adult↗