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Biomedical subjects

A Radaelli

Publications and source records attributed to A Radaelli.

53 records · Page 3Linked to original sources
PubMed1991

Angiotensin-converting enzyme inhibition and physical training in heart failure.

A total of 12 patients (mean age +/- SEM 63 +/- 2.6 years) with moderate to severe heart failure (ejection fraction = 23 +/- 3.2%) were included in a placebo-controlled crossover trial. Patients were randomly allocated to 4 periods of 6 weeks each: placebo, placebo and physical training, lisinopril 10 mg daily, and lisinopril and physical training. The exercise time increased from 13.6 +/- 0.9 min with placebo to 15 +/- 1 min with training alone, and to 16.1 +/- 0.7 min with lisinopril and training. With lisinopril alone there was a non-significant increase in exercise time, to 14.5 +/- 0.6 min. Improvements in exercise time were accompanied by a similar increase in peak oxygen consumption. Overall, the most significant improvements in symptoms and indices of cardiorespiratory fitness were achieved with a combination of lisinopril and training. Thus physical training is not only a useful adjunct to the existing medical therapy for heart failure, but it may also provide symptomatic benefits in its own right.

Aged↗
PubMed1991

[The variability of the heart rate, arterial pressure and peripheral circulation as the indices of autonomic control in essential hypertension].

In recent years the influence of autonomic nervous system on cardiac rhythm and blood pressure has been increasingly studied by analysis of cardiovascular fluctuations, particularly in diabetic and normal persons under various physiologic conditions, while still few data exist on essential hypertension. To characterize the autonomic cardiovascular control in essential hypertension we studied 22 untreated hypertensives, diagnosed within 1 year (mean age 43 +/- 2 years, mean +/- SEM) and 16 age-matched normotensives. Recordings of RR interval, breathing activity, noninvasive blood pressure (Finapres) and skin arteriolar flow (infrared photoplethysmogram) were obtained while in supine position and after sympathetic activation induced by passive transition to upright posture (tilting table). Autoregressive power spectral analysis was then carried out, and low- (0.03-0.15 Hz, LF) and high-frequency fluctuations (0.15-0.35 Hz, HF) were measured. LF and HF have been considered as markers of sympathetic and parasympathetic activity on the heart, respectively, and as markers of sympathetic and mechanic chest activity on the circulation, respectively. In supine position both cardiac and vascular variability were similar in both hypertensive and normotensive groups. After tilting however the increase in the sympathetic component of cardiac variability was blunted in hypertensives with respect to normotensives (hypertensives LFnu from 43.6 +/- 4.7 nu to 59.4 +/- 5.1 nu, p less than 0.005; normotensives LFnu from 36.9 +/- 3.3 nu to 83.4 +/- 2.6 nu, p less than 0.001), the increase in LFnu being statistically (p less than 0.001) reduced in the hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Ambulatory blood pressure monitoring: validation of the accuracy and reliability of the TM-2420 according to the AAMI recommendations.

The accuracy of the TM-2420 ambulatory blood pressure monitor (A&D Co, Japan) has been assessed by the indirect method according to the recommendations of the Association for the Advancement of Medical Instrumentation (AAMI). Ninety subjects (43 men and 47 women), aged 19-89 with a range of systolic blood pressures (SBP) of 81-211 mmHg and diastolic blood pressures (DBP) of 32-113 mmHg were studied. The monitor was compared with two observers using the Hawksley random zero sphygomomanometer. The standard deviation of the difference (SDD) between the observers was 3.0 mmHg for SBP and 2.3 mmHg for DBP. The mean differences between observers were -0.31 mmHg for SBP and 0.32 mmHg for DBP (both NS). The average of three readings for each subject recorded by the monitor was compared with the average of the simultaneous readings by the observers. The SDD was 7.2 mmHg for SBP and 5.5 mmHg for DBP (within the recommendations for accuracy). The differences between methods were -0.98 mmHg for SBP and 0.18 mmHg for DBP; these differences were not significant (NS). The monitor was also assessed against direct intra-brachial artery pressure in 12 subjects (36 readings). The mean difference between the monitor and simultaneous individual intra-arterial reading was -9.5 mmHg for SBP (P less than 0.001) and 3.7 mmHg for DBP (P less than 0.001). The SDD's between methods were 12 mmHg for SBP and 5.0 mmHg for DBP. Use of the monitor in general clinical practice in 100 patients was also assessed. The rate of errors was low (6.8%), and the device found to be acceptable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Ambulatory blood pressure in relation to drug treatment and clinical trials.

Spontaneous differences in blood pressure from one clinic visit to another inevitably lead to the use of unnecessarily high doses of drugs in the treatment of hypertension and to unnecessarily high recommended doses of new antihypertensive drugs. This can be avoided by the use of ambulatory blood pressure monitoring. The improved reproducibility achieved by ambulatory monitoring substantially reduces the number of subjects required to detect small differences in pressure between one treatment and another. Furthermore, 24-h monitoring eliminates time-related fluctuations and makes it possible to use crossover trials to compare the antihypertensive effects of different drugs. Differences of 5 mmHg in diastolic pressure between two treatments can thus be detected in a trial on less than 20 subjects.

Antihypertensive Agents↗
PubMed1990

[Platelet adrenergic alpha receptors in hypertensive subjects undergoing treatment with calcium antagonists].

The effects of two different calcium-channel blocking agents on platelet alpha-2 adrenoceptors were studied in 18 mild to moderate hypertensive patients. The subjects were randomly assigned in a double blind fashion to treatment with either nifedipine 10 mg t.i.d. or tiapamil 300 b.i.d. for six weeks. Platelet alpha-2 receptors were studied before and following 6 weeks of treatment using radioligand binding assay (3H Rauwolscine). Both agents induced a reduction in alpha-2 receptors, which reached statistical significance only for nifedipine. Such a reduction may contribute to the antihypertensive effect of calcium-channel blocking drugs.

Adult↗
PubMed1990

[Blood platelet alpha adrenergic receptors in congestive heart failure. Effects of ACE inhibition].

Platelet alpha-2-adrenergic receptor number and affinity were examined in 12 patients with class IV NYHA congestive heart failure (CHF) and 10 normal volunteers paired for age and sex. Platelet alpha-2-adrenergic receptor number is significantly decreased in CHF patients (178 +/- 18 fmol/mg prot. vs 282 +/- 21 fmol/mg prot. p less than 0.05). After Captopril treatment (6 weeks) alpha-2-receptor number increased but this increase was not statistically significant (236 +/- 28 fmol/mg prot.). This study supports the hypothesis that increased levels of circulating catecholamines in CHF lead to a decrease in platelet alpha-2-adrenoreceptors. Improved cardiac function following administration of Captopril could lead to a withdrawal of sympathetic tone. Captopril may also interact with sympathetic nervous function.

Aged↗
PubMed1988

Biological and molecular analysis of LCV, an endogenous retrovirus with defective env gene.

Retrovirus infectivity is the result of a cooperative interaction of three structural genes, gag, pol, and env. Since the L-cell endogenous retrovirus (LCV) lacks the env gene translation product, our aim was to study the biological and molecular basis of its non-infectiousness. Fusion experiments between LCV and homologous or heterologous cells demonstrated that virus production could be obtained only after LCV artificial penetration in murine cells and that the new progeny was still noninfectious. Northern blot analysis and heteroduplex mapping of the genomic RNA revealed a 0.99 kb deletion including the 3' region of the pol reading frame, the whole xenotropic and part of the ecotropic domain of the env gene. The results suggest that the observed deletion is responsible for the absence of the gp 70 and the gp 15 E molecules in the virion and seems therefore to be the molecular basis for the non-infectiousness of this retrovirus.

Blotting, Northern↗
PubMed1988

Plasma melatonin levels in psoriasis.

Melatonin is synthesized and secreted by the pineal gland. A daily rhythm of melatonin secretion, with high plasma values during the dark period, has been found in all vertebrates studied so far. In psoriatics, several hormones, including GH and prolactin, have altered chronobiology, and some studies in humans suggest that melatonin affects the levels of GH and prolactin. We investigated circadian melatonin rhythm in 13 male psoriatics and 13 healthy males with an RIA specific for measuring the hormone in plasma. Samples were taken at 6 a.m., 8 a.m., 12.00, 4 p.m., 8 p.m. and 2 a.m. Differences in (mean +/- SD) plasma melatonin levels were analysed by Student's t-test. Our results show that psoriatic patients had lost the nocturnal peak and usual circadian rhythm of melatonin secretion. Levels of melatonin were significantly lower than in controls at 2 a.m., and higher at 6 and 8 a.m. and at 12 noon. Further investigations of this disorder of melatonin secretion in psoriasis are needed to understand its significance.

Adult↗
PubMed1987

Increase in plasma HDL-cholesterol in hypertensive patients treated with enalapril.

The effects of enalapril on plasma lipoproteins were evaluated in an open study of 12 normolipidemic outpatients with mild-to-moderate essential hypertension (World Health Organization stages I and II). After a two-week washout period, during which placebo was given, the patients received 20 to 40 mg/day of enalapril for 16 weeks. Treatment with enalapril was associated with significant increases in levels of HDL cholesterol (mean, 23%; P less than 0.001) and apoprotein A (mean, 11%; P less than 0.01), largely because of the increase in the subfraction HDL2 (mean, 43%; P less than 0.001), although the subfraction HDL3 also rose (mean, 14%; P less than 0.005). Total cholesterol and LDL cholesterol levels did not change, whereas triglycerides decreased significantly (mean, 26%; P less than 0.001). Apoprotein B was unchanged. Unlike diuretics and most beta-blockers, enalapril favorably affects plasma lipoprotein levels, thus improving the overall cardiovascular risk in hypertensive patients.

Adult↗
PubMed1985

Circadian rhythm of the in vivo migration of neutrophils in psoriatic patients.

Neutrophil chemotaxis in ten subjects with psoriasis was evaluated in vivo by the quantitative skin-window technique using autologous serum and in vitro using a modified Boyden technique. The in vitro chemotaxis values of the psoriatics were significantly lower (P less than 0.01) than those of healthy controls. When measured in vivo, however, we found that, after 9, 12, and 24 h, the values of the migrating polymorphonuclear leukocytes (PMNL) of psoriasis patients were only slightly and non-significantly lower than normal values. Analysing the in vivo chemotaxis data by a chronobiological method, we demonstrated statistically significant circadian rhythms in nine of the ten psoriasis patients. In seven of the patients, we found that the population had a significant rhythm, with the acrophase at -328 degrees. Our in vitro and in vivo values are in agreement with previously published values. However, there was a definite circadian rhythm of migration that we could not demonstrate in normal controls. We consider that our data reveal a significant and important difference between neutrophil chemotaxis in vivo in normal subjects and that in patients with psoriasis.

Adult↗
PubMed1985

Differential expression of surface proteins, virus receptors and histocompatibility antigens in SV40-transformed human choroid cells and their clones.

Human choroid (HC) cells transformed by Simian virus 40 (HC/SV40) and some of their soft agar-derived clones were utilized to study the influence of SV40 transformation on the expression of some differentiation parameters. The presence of receptors for DNA and RNA viruses, known to induce cytopathic effects in target cells, always occurred in normal HF and HC/SV40 cells as well as in their derived clones, whereas differences were observed in the expression of influenza A and Sindbis virus receptors. Immunofluorescence assays showed an increase in the expression of class I (HLA-A/B/C) and class II (DR) histocompatibility antigens in hyperdiploid clones compared with both the hypodiploid clones and the normal human cell counterpart. The two surface glycoproteins, fibronectin and laminin, appear only partially correlated with the transformed phenotype of the cells both at optical (immunofluorescence) and supraoptical (immunoelectron microscopy) level. This study confirms the SV40 transformation induces in human choroid cells a modulation of the considered differentiation parameters and that this may be due to a different insertion mode of the SV40 genome in HC cells.

Amnion↗
PubMed1984

Ultrastructural and biochemical evidence that the L929 cell retrovirus lacks the env gene translation product.

LCV, a murine retrovirus released by L929 mouse cell fibroblasts, is non-infectious when inoculated into SC-1, mink, D-17 or Vero cells. Ultrastructural examination by thin sectioning, freeze-etching or negative staining revealed the absence, on the viral envelope, of the radially disposed spikes. Polyacrylamide gel electrophoresis of radiolabelled viral components showed the absence of the glycosylated protein gp70 as well as of the p15E cleavage product of the polyprotein precursor gPr90env. The premature loss of the gp70 molecule from LCV to the culture medium was ruled out since no peak of D-[14C]glucosamine-labelled glycoprotein was detected by affinity chromatography or immunoprecipitation of concentrated medium. The ultrastructural and biochemical results all supported the hypothesis that the absence of infectivity was due to the lack of gp70 glycoprotein in the envelope of LCV. A possible block at a translational or post-translational level was also investigated by immunofluorescence studies with antisera directed against ecotropic or xenotropic gp70; Moloney murine leukaemia virus-infected or NZB cells were used as positive controls for eco- or xenotropic viruses respectively. The absence of fluorescent stain in L929 cells further supported these results and suggested that LCV and the L929 parental cell line lack the uncleaved precursor and the final product of the env gene translation process.

Animals↗
PubMed1984

Transformation of human choroid cells in vitro by SV40. Ultrastructural and cytogenetic analysis of cloned cell lines.

Several clones were isolated from a Simian Virus 40-transformed human choroid cell line (HC/SV40) by the soft agar plating technique. Five of them which showed different morphology, growth capacity and cell density, were plated in monolayer and subjected to ultrastructural, immunological and cytogenetic analyses. The morphological features at both TEM and SEM were distinct for every examined clone but uniform in the cells of the same clone. In particular clone 3 (HC/SV40-C13) showed a greater increase of intracytoplasmic granules, a marker of all cells of choroid origin, while clone 2 (HC/SV40-C12) was totally devoid of them. No virus production was observed at the electron microscope. Immunofluorescence experiments revealed 100% positivity for nuclear T-antigen in all the clones, thus demonstrating the persistence of SV40 genome in these cells. Cytogenetic analysis showed a hyperdiploid number of chromosomes in clones 1 and 3, while clones 2 and 4 were clearly hypodiploid. All clones showed a general tendency to cytogenetic stabilization as compared to the karyotypes found in HC/SV40 parental cell line.

Cell Division↗
PubMed1983

Identification by monoclonal antibodies of a new epitope in the glycoprotein complex of Sindbis virus.

Monoclonal antibodies against a deletion mutant of Sindbis virus were produced and characterized in order to determine the fine mapping and functional activities of single viral epitopes. All monoclonal antibodies so far tested showed a certain degree of reciprocal competition and were directed against an antigenic determinant which was present only on the undissociated complex of the E1 and E2 glycoproteins. A biological assay measuring viral haemagglutination showed no decrease in the titre of viral samples preincubated with monoclonal antibodies. Conversely, a reduction in viral infectivity was demonstrated, particularly with two of these antibodies. The results suggest that the antibodies which we characterized seem to recognize a new epitope which is represented on both glycoproteins on the surface of this mutant of Sindbis virus.

Animals↗
PubMedDate not supplied

Circadian temporal structure in psoriasis.

The unknown etiopathogenesis of psoriasis and its often unpredictable course, in spite of actual treatment, suggest the search of parameters correlated with the disease that could help to better define and treat these patients. The altered cell turnover of the psoriatic epidermis leads to hypothesize a disturbance or at least a modification of the cellular rhythm of the skin. In order to prove alterations of the circadian temporal structure in psoriasis, we have studied some easily detectable variables, registered at 3-h intervals, in both psoriatic and in healthy control subjects. The control subjects presented statistically significant circadian rhythms of oral temperature, arterial blood pressure, pulse, electrolytes, 17KS, 17-OHCS and uricemia. In the psoriatic group, only a few of these variables present a clearly reproducible circadian rhythm. Moreover these rhythms, when they are demonstrable in the patients, do not show the same circadian acrophases of the control subjects and they are also desynchronized inside the group itself. The alteration in these circadian urinary and haematic rhythms implies that in psoriasis not only the skin is involved: all the circadian structure seems to be perturbed and the cause of the disease should mot be searched only in the epidermis.

17-Hydroxycorticosteroids↗