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Biomedical subjects

L Guidi

Publications and source records attributed to L Guidi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cerebellar deficit and respiratory impairment: a strong association in multiple sclerosis?

The aim of the study was to analyse pulmonary function and to identify reliable prognostic factors associated with respiratory abnormalities in a consecutive series of patients with multiple sclerosis (MS). Pulmonary function was evaluated by means of a battery of measures, including maximal voluntary ventilation, forced vital capacity, forced expiratory volume, in 71 consecutive patients with primary and secondary progressive MS. Respiratory impairment was common in MS patients, occurring in 63.4% of all patients, ranging from 82.9% in non-ambulatory patients (with EDSS score >6.5) to 35.7% in ambulatory patients (with EDSS score <6). Severity of illness and cerebellar and mental impairment were significantly negatively associated with basal pulmonary function. Coordination plays an important role in determining respiratory abnormalities: respiratory abnormalities were found in 27 out of 32 patients (84.4%) with severe cerebellar impairment. The presence of severe cerebellar signs was associated with a very high risk of occurrence of respiratory impairment (O.R. = 6.24; 95% C.I. 1.71-22.82). Other significant variables were severity of illness (EDSS score > 6.5) (O.R. =4.71; 95% C.I. 1.42-15.66) and long disease duration (> 15 years) (O.R. = 3.39; 95% C.I. 1.01-11.42).

Analysis of Variance↗
PubMed1999

High glucose-6-phosphate dehydrogenase activity contributes to the structural plasticity of periglomerular cells in the olfactory bulb of adult rats.

Glucose-6-phosphate dehydrogenase (G6PD) activity, assayed spectrophotometrically, was found to be higher in the olfactory bulb (OB) than in other brain areas of adult rats [P. Ninfali, G. Aluigi, W. Balduini, A. Pompella, Glucose-6-phosphate dehydrogenase is higher in the olfactory bulb than into other brain areas, Brain Res. 744 (1997) 138-142]. Histochemical demonstration of G6PD activity in cryostat sections of OB, analyzed with optical microscopy, revealed a marked and well defined line of formazan deposition in the internal part of the glomerular layer (Glm), indicating that G6PD was much higher in cells distributed along the glomeruli. Electron microscope analysis showed that G6PD activity was mainly concentrated in cytoplasm and dendrites of periglomerular cells, the interneurons which span glomeruli and connect olfactory nerves with mitral/tufted cells. Since G6PD regulates the flux through the hexose monophosphate shunt (HMS) pathway, which provides NADPH for reductive biosynthesis and pentose phosphates for nucleic acid formation, it can be concluded that high G6PD activity in periglomerular neurons is functional to their differentiating capability. This result is consistent with the occurrence of structural plasticity events in the OB of adult rats.

Animals↗
PubMed1999

Effect of age on DNA binding of the ku protein in irradiated human peripheral blood mononuclear cells (PBMC).

DNA binding of the ku protein was investigated in peripheral blood mononuclear cells (PBMC) from 24 subjects of different ages (20-89 years old) displaying age-related changes in DNA repair, mitotic responsiveness, and cytokine production. Ku is an heterodimeric protein composed of two subunits of 70 and 80 kDa, which is involved in the earliest steps of DNA damage recognition. DNA binding of ku 70/80 was found unchanged in normal PBMC from aging subjects but progressively declined in x-ray-irradiated PBMC from young to adult, and elderly subjects. This finding was concomitant with the age-related fall of DNA repair in the whole population.

Adult↗
PubMed1999

Characteristics of gastric-vein lymphocytes with regard to the immune response to Helicobacter pylori.

BACKGROUND: Between peripheral blood and tissue-infiltrating lymphocytes there is an intermediate compartment, the blood of the organ-draining vessels, which could show unusual features. The aim of the present study was to analyse the characteristics of the lymphocytes from the stomach-draining vessels and the cytokine secretion by these lymphocytes. The CagA-mediated lymphocyte activation in Helicobacter pylori-infected subjects and the humoral response to this antigen were evaluated and correlated with clinical data. METHODS: We studied lymphocyte proliferation either with mitogens or with the CagA antigen and cytokine production and IgG anti-CagA by means of an enzyme-linked immunosorbent assay in peripheral blood and gastric-vein blood obtained during surgical intervention. RESULTS: We showed higher proliferative response and cytokine production in lymphocytes from the gastric vein. The mitogenic response to the CagA antigen was highly specific but poorly sensitive for the H. pylori infection in both the compartments. The overall cytokine profile in our patients affected by non-ulcer disease was of the Th0 type. CONCLUSIONS: Gastric-vein-derived lymphocytes seem to show unusual features, as they behave like peripheral blood lymphocytes but show higher responses to all the tested stimuli. It is possible that the interaction of the lymphocytes with the mucosal environment could activate the synthetic mechanisms, making the cells more 'responsive' to the stimulation. The CagA antigen is able to induce a specific T-lymphocyte response and is therefore a valid candidate antigen for the development of a vaccine.

Adult↗
PubMed1999

Hypotonic saline infusion alters the renal response to amino acids in men.

We investigated the effects of hypotonic saline-induced modifications of extracellular volume and sodium handling on the renal and metabolic response to amino acids (AA). Renal hemodynamics (Inutest, p-aminohippurate clearance), plasma AA, and glucagon levels, as well as urea and sodium excretion, were studied in seven adult volunteers infused for 2 h, on six separate occasions, according to the following protocols: 1) high-AA solution (300 mg. min-1. 1.73 m-2); 2) low-AA solution (150 mg. min-1. 1.73 m-2); 3) low AA + 2,000 ml/1.73 m2 of 0.23% saline solution; 4) high AA + 0. 23% saline; 5) high AA + 0.45% saline; and 6) 0.45% saline alone. The glomerular filtration rate (GFR) rise induced by the high-AA solution was similar to that induced by the low-AA solution (DeltaGFR = +24 +/- 6 and +20.2 +/- 7 ml. min-1. 1.73 m-2, respectively), whereas the plasma AA and glucagon levels and urea excretion rate increases were related to AA dose. The addition of 0. 23% saline to the low-AA solution and of 0.45% saline to the high-AA solution blunted the renal hemodynamic response (DeltaGFR = +6.6 +/- 10.1 and +11.4 +/- 8.3 ml. min-1. 1.73 m-2, respectively) without modifying the pattern of plasma AA and glucagon levels and urea excretion observed with the AA infusion alone. Urinary sodium excretion increased from baseline with each protocol and rose even further when saline was added to AA. A negative correlation (r = -0. 38, P < 0.05) was found between the changes from basal values in GFR and those in sodium excretion rate with high-AA infusion at different levels of sodium concentration. These data suggest that AA-induced hyperfiltration might be blunted by hypotonic saline infusion, possibly through an acute modification of renal sodium handling and extracellular volume.

Adult↗
PubMed1999

Neuropeptide Y plasma levels and immunological changes during academic stress.

Academic stress is a good model of psychological stress in humans for studying psychoneuroimmune correlations. We looked for correlations between psychological scores, immune tests and plasma levels of cortisol and neuropeptide Y (NPY). A group of medical students were evaluated at the beginning of the academic year (Baseline) and the day before an examination (Stress). They underwent evaluation by The Profile of Mood States (POMS), The Malaise Inventory, The Self Efficacy Scale and A Global Assessment of Recent Stress (GARS). The lymphocyte subsets, the lymphocyte proliferative response and the cytokine production were also evaluated. We detected modifications of some psychological test scores between the Baseline and Stress evaluation, a significant reduction of lymphocyte proliferation, IL-2 production and percentage of the lymphocyte CD19, and an increase in plasma cortisol levels during stress. The lymphocyte proliferation negatively correlated with the POMS score as well as the percentage of CD16+ cells with NPY plasma levels. NPY levels were not different from Baseline. The emotional and mood states seem to influence immunity. Copyrightz1999S.KargerAG,Basel

Adaptation, Psychological↗
PubMed1998

Changes in the amount and level of phosphorylation of p56(lck) in PBL from aging humans.

The effects of aging on the activation of the cytoplasmic tyrosine protein kinase p56(lck) have been investigated in PBL from adult and elderly subjects upon activation with mitogens or different co-stimuli. Results show that the amount and phosphorylation of p56(lck) are reduced in PBL from elderly as compared to adult subjects. This finding suggests that alterations in p56(lck) may contribute to the age-associated loss of some T cell functions, such as proliferation and IL-2 production, which are found decreased in PBL from old individuals. However, p56(lck) seems irrelevant to the production of IFN-gamma and IL-4 which were both found increased in the PBL from old subjects, as expected from the relative expansion of memory versus naive T cell subpopulations in aging.

Adult↗
PubMed1998

Cell proliferation and ku protein expression in ageing humans.

Previous studies on DNA repair in ageing have demonstrated increased frequencies of single and double strand breaks in lymphocytes from elderly subjects and, as a consequence, decreased efficiency in DNA replication. We have investigated the relationship between cell proliferation and the nuclear expression of ku protein in a human population of 43 subjects of different ages. Ku is an heterodimeric protein composed of two subunits of 70 and 80 kDa, which is involved in the early steps of DNA damage recognition. In the present study, PBL from subjects of different ages were PHA-activated to evaluate the stimulation index and the production of Th1- and Th2-type cytokines. Moreover, nuclear extracts were obtained from activated lymphocytes to evaluate by a gel retardation assay the presence and the functional activity of the heterodimer ku 70/80. Our results indicate that ageing affects the mitotic responsiveness and cytokine production to a significant extent, but only marginally the expression of ku 70/80. These findings suggest that the age-related impairment in DNA repair mechanisms are only in part related to the reduced expression of ku protein able to recognize DNA damage.

Adult↗
PubMed1998

The effect of zinc and vitamin A supplementation on immune response in an older population.

OBJECTIVE: To determine if either supplemental vitamin A, zinc, or both increases cell-mediated immune response in an older population. DESIGN: A double-blind, randomized, controlled trial of supplementation with vitamin A and zinc. SETTING: Casa Di Riposo Roma III, a public home for older people in Rome, Italy. SUBJECTS: The health and nutritional status of 178 residents were evaluated. One hundred thirty-six residents agreed to participate in the trial and were randomized into four treatment groups, and 118 of these residents completed the trial. INTERVENTION: The four treatments consisted of: (1) Vitamin A (800 micrograms retinol palmitate); (2) Zinc (25 mg as zinc sulfate); (3) Vitamin A and Zinc (800 micrograms retinol palmitate and 25 mg as zinc sulfate); (4) Placebo capsules containing starch. MAIN OUTCOME MEASUREMENTS: Immune tests-counts of leucocytes, lymphocytes, T-cell subsets, and lymphocyte proliferative response to mitogens-were measured before and after supplementation. RESULTS: Zinc increased the number of CD4 + DR + T-cells (P = .016) and cytotoxic T-lymphocytes (P = .005). Subjects treated with vitamin A experienced a reduction in the number of CD3 + T-cells (P = .012) and CD4 + T-cells (P = .012). CONCLUSIONS: These data indicate that zinc supplementation improved cell-mediated immune response, whereas vitamin A had a deleterious effect in this older population. Further research is needed to clarify the clinical significance of these findings.

Aged↗
PubMed1998

Metabolic factors in the renal response to amino acid infusion.

In order to investigate the renal effects of amino acids (AA) with different metabolic fate, we compared the changes in glomerular and tubular function, nitrogen metabolism and glucoregulatory hormones in 7 volunteers during two infusions, one of a complete solution of amino acids (MIX-AA), which included five AA electively metabolized at the splanchnic level, and the other of a solution containing only essential AA (EAA), which escape splanchnic metabolism. MIX-AA increased GFR and RPF (from 104 +/- 6 to 122 +/- 13 and from 488 +/- 46 to 572 +/- 34 ml/min/1.73 m2), stimulated splanchnic metabolism as demonstrated by rises in urinary urea excretion (from 20.7 +/- 2 to 30.6 +/- 7.5 mg/min/1.73 m2) and the plasma glucagon/insulin ratio (from 21.4 +/- 13 to 26.7 +/- 15), and caused increases in fractional excretion of AA, FeNa and free-water clearance. During MIX-AA infusion significant correlations were observed between the individual values of GFR and the urea excretion rate (r = 0.66), and between GFR modifications (DeltaGFR) and the plasma glucagon/plasma insulin ratio (r = 0.40). No change in renal function, urea excretion and the glucagon/insulin ratio was observed with EAA. An intermediate splanchnic step (increased plasma glucagon/insulin ratio and ureagenesis) seems necessary in the pathway leading to the nonessential AA-induced rise in GFR; this might stimulate an ultimate intrarenal pathway (possibly involving the diluting segment) via a still undefined mechanism.

Adult↗
PubMed1998

Psychoneuroimmunology and aging.

BACKGROUND: The senescence of the immune system is a complex phenomenon, characterized by impairment of several lymphocyte activities and generally considered a state of immune dysregulation. Aging is a condition associated with many social changes likely to induce psychological stress, which is often perceived as uncontrollable and can lead, in some cases, to clinically relevant depression. In the recent years a growing interest has been raised for the study of bidirectional interactions between the central nervous system and the immunological network (psychoneuroimmunology). OBJECTIVE AND METHODS: We analyzed the possibility that chronic psychological distress and depression could worsen some immune functions in the aged. We postulate the neuroendocrine mechanisms of psychoimmune interaction, analyzing both the human and animal studies focused on aging. RESULTS: The data from the literature reviewed suggest a significant impact of affective disorders on immune functions in the elderly subjects. This psychoimmune imbalance appears particularly important when the studies are carried out in otherwise healthy aged people. CONCLUSIONS: Here we reviewed the relationships between psychological stress and depression and immunological functions, with particular regard to those aspects pertinent to the aging process. The clinical relevance of these interactions remains to be elucidated, but the high frequency in the aged of autoimmune, infectious, and neoplastic diseases suggests to focus on the psychoneuroimmune interactions in the old age. We also propose some outlines for future studies concerning psychoneuroimmunology and aging.

Aging↗
PubMed1997

Differential dynamic responses of luteinizing hormone to gonadotropin releasing hormone in patients affected by bulimia nervosa-purging versus non-purging type.

OBJECTIVE: Aim of the study was to investigate the presence of underlying abnormalities affecting the hypothalamus-pituitary-gonadal axis in 13 normal weight eumenhorreic bulimics as expressed by a different gonadotropin response to gonadotropin releasing hormone (GnRH), comparing patients with (n = 6) and without (n = 7) purging behaviours to controls (n = 5). METHOD: Subjects were administered an intravenous GnRH infusion for four hours, with an additional bolus at first and third hour. RESULTS: Non-purging bulimics showed a significantly reduced luteinizing hormone (LH) response to GnRH compared to controls; purging bulimics, following the second bolus, demonstrated a statistically reduced peak, in comparison to both controls and non-purging bulimics. DISCUSSION: even in the absence of overt menstrual disturbances, an altered LH secretion elicited by pulsatile stimulation of endogenous GnRH was found, with a more severe impairment in purging than in non-purging bulimics, possibly related to their greater psychopathological and physical burden.

Adolescent↗
PubMed1997

Airway stenosis after tracheo-bronchial tuberculosis.

Primary endobronchial localization of tuberculosis without change on chest X-ray is a rare clinical entity, and bronchoscopic examination is most appropriate to reveal such an occurrence. A 38-year-old man and a 52-year-old woman underwent fibre-optic bronchoscopy many months after the onset of cough with poor sputum and dyspnoea on exercise, chest X-ray being normal. In both cases, a widespread granulomatous involvement of the tracheo-bronchial tree was found and cultures of bronchial wash grew Mycobacterium tuberculosis. Patients recovered after 6 months of combined anti-tuberculous and steroid therapy; the granulomatous lesions disappeared but stenoses were found in the trachea and/or main bronchi. In one case, CO2 laser therapy was performed with no improvement.

Adult↗
PubMed1997

Pulmonary alveolar microlithiasis: review of Italian reports.

Pulmonary alveolar microlithiasis (PAM) is a rare disease of unknown etiology, characterized by the presence of calcific concretions in the alveolar spaces. A familial occurrence is frequently found so that an inherited trait is thought to be involved. The chest X-ray is characterized by a 'sandstrom' picture while the clinical state undergoes to a slow and progressive impairment resulting in respiratory failure at the end stage. We have reviewed the Italian literature of the past 50 years detecting 48 case-reports of PAM (19 males and 29 females). Only 20 out of them were documented in international journals. A familial occurrence of 43.7% was found and 18 patients were under age fifteen. There was a prevalence in the female sex (60.4%) and in the second decade of life. Chest X-ray was the most important tool to diagnose PAM revealing the characteristic picture in all patient. Bronchoalveolar lavage (BAL) and open lung biopsy respectively show the characteristic calcospherites in the recovered fluid (BALF) and in the alveolar spaces. About 300 cases of PAM are reported in the international literature. We believe these data are probably underestimated because many case-reports are not published in international literature.

Adolescent↗
PubMed1997

Pulmonary microlithiasis. Report of two cases.

Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by widespread localization of calcispherites in the alveolar spaces. The patients are symptomless for a long time. Nevertheless, this disease slowly develops into pulmonary fibrosis and cardiac failure. The chest X-rays and high-resolution computed tomography strongly point towards a diagnosis of PAM. As for therapeutic approaches, repeated broncho-alveolar lavages (BAL) have been performed with improvement of symptoms but without recovery, and a new oral drug treatment is still under way. We report 2 familial cases of PAM. Both patients underwent chest X-ray examination showing diffuse bilateral micronodular opacities of calcific density. After 5 years, in May 1993, one of them developed exertional dyspnoea, cyanosis, dry cough and was admitted to our Division. Cardiokinetic and diuretic drugs as well as oxygen were administered with satisfactory results. Then repeated BAL were performed. The chest X-ray after 6 months of sodium etidronate (300 mg t.i.d.) administration was unchanged.

Adult↗
PubMed1997

Adverse drug reaction to rifampin: a case with long lasting antiplatelet antibodies.

Rifampin is a drug able to induce adverse reactions involving both the kidney and the hematological system. We observed a case, throughly studied and we deemed worth-while to report it, for some important features that were evident. Transient hemolytic anemia, recoverable acute renal failure, persistent increased titer of anti-platelet antibody lasting also after 3 weeks from the withdrawal of the drug and in spite of corticosteroid therapy, could be explained by the immune mechanisms that are, therefore, postulated.

Aged↗
PubMed1996

Non-fibrous inorganic particles in bronchoalveolar lavage fluid of pottery workers.

AIM: To study the actual exposure of pottery workers to silica particles, as their risk of silicosis is potentially high because of the presence of inhalable crystalline silica particles in the workplace. METHODS: Nine pottery workers underwent bronchoalveolar lavage. The recovered fluid was analysed for cytological and mineralogical content by analytical transmission electron microscopy. The data were compared with those obtained from a control group composed of seven patients with sarcoidosis and six patients with haemoptysis. RESULTS: Cytological results showed a similar profile in exposed workers and controls, whereas in patients with sarcoidosis a lymphocytic alveolitis was found. Microanalysis of the particulate identified the presence of silicates, CRSs, and metals. Pottery workers had higher numbers of total particles and CRSs, and had a higher silicate/metal ratio. In five workers, the presence of zirconium silicate was also detected. Patients with sarcoidosis had the lowest number of particles, and an inverted silicate/metal ratio. CONCLUSION: Microanalysis by transmission electron microscope can provide useful information to assess occupational exposure to dusts.

Adult↗