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Biomedical subjects

R Arena

Publications and source records attributed to R Arena.

At least 19 recordsLinked to original sources
PubMed2002

Fish immunology. II. Morphologycal and cytochemical characterization and phagocytic activities of head kidney macrophages from rainbow trout (Salmo gairdneri Richardson).

In Salmo gairdneri Richardson trouts, a comparison was made between macrophages (MO) derived from head kidney and peripheral blood monocytes. Morphologically and cytochemically no differences were observed between these two types of mononucleated cells. On the other hand, in parallel studies the ability of trout erythrocytes to engulf Candida albicans (CA) was evaluated and compared to the MO phagocytosis. In erythrocytes, engulfment is preceded by binding to CA and cell membrane invagination, while this was not the case for MO. Finally, MO stimulated with lipopolysaccharides (LPS) did not modify their phagocytic capacities, thus suggesting a lack of LPS receptors or a tolerance to LPS.

Animals↗
PubMed2001

Measurement of oxygen consumption on-kinetics during exercise: implications for patients with heart failure.

Oxygen consumption (VO(2)) on-kinetics describes the rate change in oxygen uptake at the initiation of exercise. Several mathematical and graphical methods are used to assess VO(2) on-kinetics during constant-load or progressive exercise. VO(2) on-kinetics is prolonged in patients with heart failure (HF) compared with individuals who have normal cardiopulmonary function. Cardiac function has been implicated as one of the controlling mechanism for this observation. The contribution that pulmonary, vascular, and skeletal muscle function makes to delayed VO(2) on-kinetics in HF has yet to be determined. VO(2) on-kinetics also appears to have clinical value in HF, although evidence supporting this claim is limited. Questions about the controlling mechanism(s) and practical application of VO(2) on-kinetics in HF therefore remain unanswered. This report provides an overview of VO(2) on-kinetics assessment techniques, reviews research pertaining to the HF population, and provides direction for future investigations.

Carbon Dioxide↗
PubMed1998

Inter-laboratory validation of solid-phase microextraction for the determination of triazine herbicides and their degradation products at ng/l level in water samples.

The accuracy and precision of solid-phase microextraction (SPME) were validated in an inter-laboratory study including ten laboratories for the analysis of triazine herbicides and their metabolites at ng/l level in aqueous samples. The SPME conditions were optimised in order to obtain maximum sensitivity. Especially, salt addition and choice of the SPME fibre coated with Carbowax-divinylbenzene increased the sensitivity. The average detection limits were in the range from 4 to 24 ng/l for the triazine herbicides, and 20 and 40 ng/l for desisopropylatrazine and desethylatrazine, respectively. The average r2 values of the calibration curves were above 0.99 for all of the analytes. The statistical data treatment was performed in accordance with the International Standardisation Organisation (ISO) standard 5725. Relative repeatability standard deviations between 6 and 14% and relative reproducibility standard deviations between 10 and 17% were found. The determined concentrations of the reference sample compared well to the "true" values, thus proving the good accuracy of the method. It is concluded that SPME is a reliable technique for the quantitative analysis of water samples containing triazine herbicides in concentrations around the European limit of 100 ng/l for individual pesticides in drinking water.

Calibration↗
PubMed1992

Further data on the development of SRIF-like immunoreactive nerve cell populations in the chick embryo brain stem. I. Medulla and pons.

Further immunocytochemical analysis of the neuroblasts with SRIF-like immunoreactivity (ir) was carried out on the chick embryo medulla and pons. 5 or 100 microns rombencephalon sections were obtained from 60 White Leghorn chick embryos at stages (E = Embryonic days) ranging from E4 1/2 to E18 and incubated with rabbit polyclonal antibodies against synthetic cyclic Somatostatin-14, according to PAP-DAB technique. In the medulla and pons the ir appeared as from E12. From E12 to E13 1/2-E14 the ir distribution gradually changed. From E14 to E18 numbers and spatial arrangement of the positive neuroblast groups did not show substantial changes; in these respects the ir distributional pattern proved to be markedly different from the one observed by the Authors in adult animals. Moreover, from E13 to E15 the positive neuroblast density appeared to be higher than that of positive neurons in adults. These results are consistent with a possible SRIF local regulative role.

Animals↗
PubMed1992

Further data on the development of SRIF-like immunoreactive nerve cell populations in the chick embryo brain stem. II. Midbrain tegmentum.

Further immunocytochemical analysis of the neuroblasts with SRIF-like immunoreactivity (ir) was carried out on the chick embryo midbrain tegmentum. 5 or 100 microns mesencephalon sections were obtained from 60 White Leghorn chick embryos at stages (E = Embryonic days) ranging from E4 1/2 to E18 and incubated with rabbit polyclonal antibodies against synthetic cyclic Somatostatin-14, according to PAP-DAB technique. In the midbrain tegmentum the ir appeared as from E12. From E12 to E13 1/2-E14 the ir distribution gradually changed. From E14 to E18 numbers and spatial arrangement of the positive neuroblast groups did not show substantial changes; in these respects the ir distributional pattern proved to be similar to the one observed by the Authors in adult animals. From E17 to E18 a decrease in the positive neuroblast density appeared to occur, particularly in a ventrally placed group. These results are consistent with a possible local regulative role of the SRIF.

Animals↗
PubMed1991

Double-labelling data on somatostatin-like and tyrosine-hydroxylase-like immunoreactivities in chick embryo brain stem. I. Pons and mesencephalon.

With the aim of investigating some factors and mechanisms of the chicken brain development, the same thick sections of brain stems from twelve E13-to-E21-aged chick embryos were sequentially tested with a rabbit anti-Somatostatin antiserum, using a PAP-DAB technique, and with anti-tyrosine hydroxylase (-TH) monoclonal antibodies, using an indirect immuno-fluorescence technique. As regards the pons and mesencephalon, the following main results were obtained. At E21 almost the same distribution of the TH-like immunoreactivity (ir) as at E13 was observed. Neuroblasts in a central, relatively wide region of mesencephalic tegmentum and in the central portion of the pons showed TH-like ir. A co-localization of the 2 immunoreactivities was detected only at E18, within some neuroblasts of the mesencephalic and pontine regions with TH-like ir. It is possible that this transitory co-localization plays a role in the development of the pons and mesencephalon of this species.

Animals↗
PubMed1990

Gerstmann syndrome: a case report.

A case of Gerstmann syndrome following a trauma is presented. After one month the patient showed the four symptoms of the Gerstmann syndrome associated with slight visual memory and constructional praxis deficits. Eight months later, however, he showed only dyscalculia, dysgraphia, right-left disorientation and finger agnosia, in accordance with selective damage of the left angular gyrus revealed by CT scan. The findings seems to support the existence and the localizing value of Gerstmann syndrome.

Adult↗
PubMed1985

Dream recall after sleep interruption in brain-injured patients.

Nineteen patients with unilateral hemispheric lesions of a vascular or neoplastic nature were studied. Before the onset of disease, these patients had experienced dream recall at least once a week. During hospitalization their dream recall was investigated using a morning diary for 10 consecutive days. During this period, seven patients reported having dreamed, whereas 12 had no dream recall. Subsequently, the patients' sleep was interrupted during both stage 2 NREM and REM sleep. With this method, 11 patients reported having dreamed at least once, whereas eight had no dream recall. Patients with lesions in the temporo-parieto-occipital region had a more frequent loss of dream recall than those with lesions outside this area. The agreement between the results obtained using the diary and those from provoked awakening was significant. The results obtained from compilation of a diary on morning awakening appear sufficiently reliable to reveal the presence or absence of dream recall in patients with focal cerebral lesions in the acute phase of the disease.

Aged↗
PubMed1984

Dream recall in patients with focal cerebral lesions.

Rare case reports have indicated that brain lesions may cause a loss of dream recall. We investigated reports of dream recallers with acute unilateral brain lesions who did not have clinical agnosia and examined 53 patients with such focal lesions clinically and radiologically. Patients with posterior lesions showed a frequent loss of dream recall while those with anterior lesions rarely did so. The cessation of dream recall was associated with defective performance in tests for visuoperceptive functions. We concluded that patients with acute posterior hemispheric lesions frequently lose their ability to recall dreams.

Brain Diseases↗
PubMed1983

Gynecomastia in epileptics treated with phenobarbital, phenytoin and fluoresone: two case reports.

Gynecomastia developed in two epileptic patients some months after the addition of oral fluoresone 750 mg daily to the phenobarbital and phenytoin already being administered. The common systemic diseases that may give rise to gynecomastia were excluded. One of the patients presented hyperprolactinemia and a raised estrogen/androgen ratio but the hormone levels were not raised in the other. The onset of symptoms after fluorescence in both cases is highly suggestive, although the pathogenetic mechanism is not clear.

Adult↗
PubMed1983

Nyctohemeral pattern of serum LH, FSH and PRL in patients with myotonic dystrophy.

The nyctohemeral pattern of serum luteinizing (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) in eight patients with myotonic dystrophy (MD) was studied. Gonadotropin patterns were classified as adult, pubertal or infantile. Six patients showed an adult pattern, whereas two had a pubertal or infantile pattern. A normal pattern of PRL secretion was found in seven patients and a blunted sleep-related hormonal increase was observed in one. Impaired hypothalamic control of pituitary secretion in MD is proposed as the cause for these findings.

Adult↗
PubMed1978

Constructional apraxia and visuoperceptive disabilities in relation to laterality of cerebral lesions.

The main purpose of the present study was to determine whether constructional apraxia is due to a visual perceptual disorder in right but not in left brain-damaged patients. In order to resolve this question, 36 normal controls and 73 brain-damaged patients with lesions restricted to the right (N = 30) or to the left (N = 43) cerebral hemisphere were given a graphomotor and a multiple choice version of the Benton Visual Retention Test. The graphomotor version of the V.R.T. was used as a test of constructional praxis, whereas the multiple choice version of the V.R.T. was used as a test of visual form discrimination. No difference was found between right and left brain-damaged patients with respect to incidence and severity of visuo-constructive and of visuo-perceptive disabilities. Contrary to the hypothesis, the relationship between perceptual and praxic tasks was higher in left than in right brain-damaged patients. The high level of correlation found between graphomotor and perceptual scores within the left hemispheric group was due chiefly to the poor performances obtained on both tasks by aphasic patients. These findings are interpreted as suggesting that the basis for visuoconstructive disturbances is a perceptual disorder, independently of the hemispheric side of lesion. The contrasting results of our intercorrelational study and of analogous studies reported in neuropsychological literature are interpreted as being due to sampling differences, in the absence of clearcut qualitative or quantitative differences between visuo-constructive disabilities of right and left brain-damaged patients.

Adult↗
PubMedDate not supplied

Altered exercise pulmonary function after left ventricular assist device implantation.

The use of LVADs as a bridge to heart transplantation is increasing steadily as more surgical centers add this effective strategy for end-stage heart failure patients. Fundamental exercise physiology in the presence of LVADs has been described previously, and data is available that supports the safety and efficacy of exercise in this population. Variants to the expected exercise response that may be secondary to LVAD implantation, such as the pulmonary restrictive pattern that developed in the patient described in this case study, may occur. Clinicians should consider assessment and monitoring of pulmonary function in this patient population, especially in patients with exercise-induced dyspnea and perhaps patients with pre-existing pulmonary limitation.

Exercise↗
PubMedDate not supplied

Safety and efficacy of exercise training in a patient awaiting heart transplantation while on positive intravenous inotropic support.

The safety and efficacy of exercise training in patients with congestive heart failure (CHF) is well established; however, the impact that exercise has on the subgroup of CHF patients awaiting heart transplant while on intravenous positive inotropic support remains largely unreported. This case study describes the safety and efficacy of exercise training in a patient awaiting heart transplant while on intravenous milrinone. Over a 1.2-year period, 246 exercise sessions were conducted with a total of 180.15 hours of aerobic exercise. During that time, the patient experienced only one hypotensive episode during exercise and had no other adverse events. The patient demonstrated a 38% increase in aerobic exercise time and a 34% increase in sustainable exercise workload. Research is needed to demonstrate the positive impact of exercise training on this subgroup of CHF patients.

Aged↗
PubMedDate not supplied

Relationship between ventilatory expired gas and cardiac parameters during symptom-limited exercise testing in patients with heart failure.

PURPOSE: This study investigates the relationship between ventilatory expired gas and cardiac parameters measured during exercise testing in patients with heart failure. METHODS: Twenty-five subjects (12 male, 13 female) diagnosed with compensated heart failure underwent symptom-limited exercise testing with ventilatory expired gas analysis. Metabolic and cardiac measures of interest were collected during testing. RESULTS: Mean peak oxygen consumption (VO2), minute ventilation/carbon dioxide production (VE/VCO2) slope, percentage of age predicted maximal heart rate achieved during exercise testing (%APMHR), and peak respiratory exchange ratio were 14.7 +/- 4.7 mL O2/kg/min-1, 33.8 +/- 9.8, 76% +/- 15%, and 1.1 +/- 0.11, respectively. The VE/VCO2 slope was significantly correlated with the following: %APMHR (r = -0.81, P < 0.001), peak VO2 (r = -0.83, P < 0.001), VO2 at ventilatory threshold (r = -0.70, P < 0.001), and the dead space to tidal volume ratio (VD/Vt) (r = 0.65, P < 0.001). The ability of peak VO2 and %APMHR to predict the VE/VCO2 slope was significant (r = 0.86, r2 = 0.72, P < 0.0001). CONCLUSION: This study demonstrates the importance of analyzing multiple exercise test parameters, including metabolic measures, in patients with heart failure.

Adult↗
PubMedDate not supplied

[Neurorehabilitation of the hemiplegic. Short-term clinical study].

The hemiplegic patients, hospitalized for focal vascular encephalopathy, have been examined and subjected to a neurorehabilitation, in order that we could estimate the possible correlations between their response to the therapy, the presence of the deficits of superior cortical functions and the anatomic lesions which gave rise to the motor deficit. The presence of aphasia, apraxia and disorder of body image give an unfavorable influence on the response to the rehabilitative therapy, similarly as what we have observed in the patients who presented symptoms of a spread neuropsychologic compromission, correlable at CT scan with a positive result of ischemic-atrophia. The younger patients, probably better adduced reasons for the treatment and with less incidence of plurifocal lesions, show a better clinical progress.

Aged↗