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Biomedical subjects

R Palumbo

Publications and source records attributed to R Palumbo.

At least 55 records · Page 3Linked to original sources
PubMed1996

1H-MRS, MRI-based hippocampal volumetry, and 99mTc-HMPAO-SPECT in normal aging, age-associated memory impairment, and probable Alzheimer's disease.

OBJECTIVE: To better understand how to differentiate the "in vivo" normal aging brain from pathological conditions, namely dementia of the Alzheimer type (DAT), by means of magnetic resonance imaging (MRI), single photon emission computerized tomography (SPECT), and proton magnetic resonance spectroscopy (1H-MRS), to show neuroanatomical, perfusional and neurochemical details, respectively. DESIGN: 1H-MRS, MRI-based hippocampal volumetry and 99mTc-HMPAO SPECT were performed in healthy older subjects as well as patients suffering from age-associated memory impairment (AAMI) and dementia of Alzheimer type (DAT). SUBJECTS AND SETTING: Eighteen subjects were selected from those referred to an outpatient clinic for diagnostic evaluation of cognitive impairment entered the study. Six patients fulfilled NINCDS-ADRDA diagnostic criteria for DAT, six subjects were affected by AAMI, and six cognitively healthy subjects, selected from among relatives of the patients, were defined as controls. METHODS: The 1H-MRS and MRI studies were performed on a 1.5 Tesla NMR-imaging system equipped with a spectroscopy research package. SPECT scans were performed on a Gamma 11 computer system. FINDINGS: 1H-MRS showed significantly lower N-acetylasparatate concentration in DAT and AAMI compared with controls. Conversely, mean inositol concentration was significantly higher in DAT than in controls, whereas AAMI subjects registered intermediate values. MRI measurements showed significantly reduced volumes of hippocampal formations in DAT and AAMI groups compared with controls. Finally, 99mTc-HMPAO SPECT showed a significant frontal, temporo-parietal, and occipital hypoperfusion in DAT patients only. CONCLUSIONS: These findings support the hypothesis of a continuum among the three conditions studied, or at least between AAMI and DAT, where AAMI seems to be an early, monosymptomatic stage of Alzheimer disease. Accepting this view, it would be questionable to maintain the term "age-associated memory impairment" as a discrete entity.

Aged↗
PubMed1995

Cyclical clodronate is effective in preventing postmenopausal bone loss: a comparative study with transcutaneous hormone replacement therapy.

An investigative study was carried out for 2 years involving 124 randomly selected early postmenopausal women with spine bone mineral density (BMD) below the mean value of a normal premenopausal subject. After random division into three groups, the first 42 patients were treated with transcutaneous 17-beta-estradiol (50 micrograms daily), the second 42 were treated with cyclical intravenous clodronate (200 mg/month iv infusion), and the third group of 40 (controls) was left untreated. After 2 years, the total drop in BMD within the control group was more than 7% as opposed to the values of -0.14% +/- 0.93 in the estradiol group and 0.67% +/- 0.84 in the clodronate group. A change in BMD of < 1% was considered satisfactory, and this result was obtained in 32% of the controls, in 79% of the estradiol group where the percentage change in BMD moderately correlated with serum estradiol levels (r = 0.399), and in 90% of the clodronate-treated patients, in whom the percentage change in BMD inversely correlated with basal values of markers of bone turnover. Both estrogen and clodronate prevent postmenopausal bone loss. The response to transcutaneous hormone replacement therapy may be influenced by transcutaneous absorption and by a lower sensitivity to estrogen. Response to cyclical clodronate seems to be influenced by the rate of bone turnover. An interdosage interval ranging from 2-4 weeks appears suitable for most patients.

Absorptiometry, Photon↗
PubMed1995

bFGF release is dependent on flow conditions in experimental vein grafts.

OBJECTIVES: Basic Fibroblastic Growth Factor (bFGF) is a powerful mitogen for smooth muscle cells and has been implicated in the genesis of Myointimal hyperplasia. The aim of this study was to determine the release of bFGF by veins in different haemodynamic conditions. DESIGN AND SETTING: Laboratory animal study. MATERIALS: In 39 Lewis rats, a 1 cm long segment of inferior vena cava was inserted at the level of the abdominal aorta. The segments of inferior vena cava were obtained from syngenic Lewis rats. Arterial Vein Grafts (AVG) were harvested after 4 weeks (AVG 4) and 12 weeks (AVG 12). In 16 animals the arterial vein grafts were explanted 4 weeks after the initial operation and reimplanted (Reimplanted Vein Grafts: RVG) in syngenic Lewis rats as venous-venous bypass grafts at the level of the left iliac vein and harvested after 2 weeks (RVG 2) and 8 weeks (AVG 8). OUTCOME MEASURES: The tissue was studied in organ culture in a serum-free system for (1) release of bFGF (immunoassay) and (2) mitogenic activity of the conditioned media. Scanning electron and light microscopy studies were also performed. RESULTS: bFGF release by veins increased significantly (p < 0.01) when veins were inserted in the arterial circulation, and decreased significantly (p < 0.01) when grafts were reimplanted in the venous system. bFGF release (ng/cm2): [Formula: see text] CONCLUSION: Vein inserted in the arterial circulation release a higher quantity of bFGF. This could explain in part, the formation of myointimal hyperplasia in arterial vein graft.

Animals↗
PubMed1995

Vasoactive peptide levels in the plasma of young migraine patients with and without aura assessed both interictally and ictally.

We measured, by RIA methods, ictal and interictal levels of substance P (SP), calcitonin-gene related peptide (CGRP) and neurokinin A (NKA) in the plasma of 30 young migraine patients with aura (MPA) and 45 migraine patients without aura (MWA), and compared the results with those of 30 age-matched controls. There were no significant differences between the levels of these vasoactive peptides in the control group and the levels in both migraine groups studied in headache-free periods. An elevation of CGRP levels in plasma was found during attacks in MPA and, to a lesser extent, in MWA (p < 0.03 and p < 0.05, respectively). A significant increase in NKA levels was also demonstrated in the MPA and MWA groups (p < 0.02 and p < 0.04, respectively). These data suggest, although indirectly, that CGRP and NKA could be involved in the pathogenesis of migraine attacks in juvenile migraine patients.

Adolescent↗
PubMed1995

Ambulatory 4-day continuous-infusion schedule of high-dose ifosfamide with mesna uroprotection and granulocyte colony-stimulating factor in advanced solid tumours: a phase I study.

BACKGROUND: There is evidence that continuous infusion allows the delivery of higher doses of a drug while reducing the incidence of neurologic and renal toxicity. To verify prior to phase II testing the feasibility of ambulatory treatment with high-dose ifosfamide/mesna by continuous infusion in adult solid tumours, the maximum tolerated dose (MTD) and the non-haematological dose-limiting toxicities for the achievement of 2 courses of therapy were determined. PATIENTS AND METHODS: Thirty-two patients with advanced solid tumours were given continuous-infusion ifosfamide, from 9 to 16 g/m2, over 4 consecutive days, with equidose mesna uroprotection and granulocyte colony-stimulating-factor support; courses were repeated every 3 weeks. Total dose/course was escalated by 1 g/m2, in cohorts of 3 to 5 patients until the MTD was determined. RESULTS: At 16 g/m2, the dose-limiting toxicity was renal, with 2 of the 5 patients treated developing renal failure. Haematological toxicity was dose-related and significant at higher dosages, but generally surmountable. Ifosfamide at 15 g/m2/course with mesna uroprotection was identified as the MTD. CONCLUSIONS: The present study shows that high-dose continuous-infusion ifosfamide, administered by portable infusion pumps, is feasible in an ambulatory regimen, with acceptable non-haematological toxicity and good patient compliance.

Adult↗
PubMed1995

Effectiveness of beta-carotene in cancer chemoprevention.

This article reviews the current knowledge on the cancer-preventive potential of beta-carotene, a precursor of vitamin A, and plentiful in fruits and vegetables, which has been studied widely as a promising chemopreventive agent in reducing the risk of cancer in humans. Several retrospective and prospective epidemiological investigations have demonstrated that a diet rich in micronutrients such as vitamins, carotenoids and selenium, could prevent the arising, in 'high-risk' patients, of precancerous and neoplastic lesions of specific sites, particularly of the upper aerodigestive tract. Numerous in vitro expressions have been performed in order to verify the true role played by this agent on cell proliferation and differentiation; until now, findings have been very encouraging, uniformly showing the beta-carotene can affect carcinogenesis, particularly in early stages, through an antigenotoxic action. Antioxidant functions, immunomodulatory effects and control of intercellular messages via gap junctions are possible action mechanisms of the ability of beta-carotene to block the carcinogenetic process. In vivo animal studies partially confirm the results obtained in vitro showing that beta-carotene is able to reduce the induce cancer development; moreover, the association of the carotenoid with other microelements, such as vitamins E, C and glutathione often appears to be more effective than each agent used alone. From a clinical point of view, beta-carotene appears an 'ideal' agent to be used in chemoprevention trials in humans, although optimal doses and intake methods need to be better defined; its almost zero toxicity permits the long-term administration of the drug, a vital condition for its anti-cancer activity, with good patient compliance. Human intervention studies performed so far, both randomized and uncontrolled clinical trials, have showed positive findings in specific cancer sites such as oral cavity, head and neck and colon; less consistent or negative are results on skin, lung and oesophagus cancer. The ongoing studies will provide more answer on these issues. A definitive evaluation of the ability of beta-carotene to prevent cancer in human requires further controlled trials; studies on a larger spectrum of cancer sites and different stages of disease must be encouraged. In addition, further investigation on biomarkers related to cancer risk and cancer incidence are necessary, particularly focused on the measurements for genotoxic damage, eg micronuclei, that may provide a valid and 'easy' marker for early stage carcinogenesis.

Animals↗
PubMed1995

Effect of bamiphylline on tracheobronchial mucus clearance in subjects with smokers' simple chronic bronchitis.

A double-blind study versus placebo was performed to assess the effect of bamiphylline, a new xanthylic derivative, on tracheobronchial mucus clearance (TBMC) in smokers with simple chronic bronchitis and impaired mucus clearance as compared to normal controls. Twenty patients were enrolled and divided into two randomized groups. The first group was treated with bamiphylline (600 mg b.d.) for 15 days, while the second group received placebo with the same oral dosage regimen. Complete clinical-functional examinations were made before and after the test period to establish the effects of treatment. At the end of the study, only the group treated with bamiphylline showed a net increase in mucus clearance (mean radioaerosol elimination 28 +/- 7% before treatment and 38 +/- 11% after treatment; p < 0.01) and an improvement in the clinical score and pulmonary function parameters, in particular the residual volume (RV = 3.41 +/- 0.75 liters before treatment and 2.7 +/- 0.6 after treatment; p < 0.01) and the forced expiratory volume at 1 s (FEV1 = 2.37 +/- 0.7 liters before treatment and 2.88 +/- 0.5 after treatment; p < 0.05). No side effects or adverse reactions that could be attributed to the study drug were observed.

Aged↗
PubMed1994

Antiproliferative and synergistic effect of interferon alpha-2a, retinoids and their association in established human cancer cell lines.

The effect of 13-cis-retinoic acid (cRA) and all-trans-retinoic acid (tRA) used alone or in combination with interferon alpha-2a (alpha-IFN 2a) was tested on three established human cell lines: KB (epidermoid carcinoma of the oral cavity), SCC-25 (tongue squamous cell carcinoma) and MCF-7 (mammary carcinoma). Both retinoids significantly decreased cell proliferation (growth curves) and colony forming efficiency (CFE) in all cell lines, in a dose-dependent way (at a concentration ranging from 10(-5) to 10(-9) M) and differing from line to line, following the pattern: MCF-7 > SCC-25 > KB. Retinoids at any concentration (already at 10(-7) M) combined with alpha-IFN 2a (ranging from 100 to 500 IU/ml) were more effective in inhibiting cell proliferation than each of the two compounds alone. This was particularly evident with SCC-25 cells. Concerning MCF-7 cells, on the contrary, the effects produced by the association suggested a possible additive more than synergistic amplification of growth inhibition.

Breast Neoplasms↗
PubMed1994

Efficacy of recombinant alpha-interferon 2a and 13-cis-retinoic acid in the treatment of squamous cell carcinoma.

BACKGROUND: Recent in vitro and in vivo studies hypothesize a synergistic effect of 13-cis-Retinoic Acid (13cRA) and recombinant alpha-IFN 2a (alpha-IFN) in the treatment of squamous cell carcinoma (SqCC). PATIENTS AND METHODS: 35 patients with SqCC in several sites were treated with 13cRA (0.6-1 mg/kg/day) combined with alpha-IFN (6 x 10(6) I.U./day), continuously for 3 months. RESULTS: We observed an objective response in 41% of cases (13/32 evaluable patients) with 5 complete and 8 partial responses. Toxicity was mild and always rapidly reversible, with no haematological side effects. CONCLUSIONS: These preliminary data confirm the feasibility and effectiveness of the combination of 13cRA and alpha-IFN in the therapy of SqCC, also in pre-treated patients, with acceptable toxicity and good compliance.

Adult↗
PubMed1994

Results, toxicity and compliance in chemoprevention trials of head and neck cancer.

Several clinical trials have demonstrated the efficacy as chemopreventive agents on upper aerodigestive tract (UADT) cancer of vitamin A or its natural precursor, beta-carotene, or its synthetic analogues, retinoids. Particularly, 13-cis-retinoic acid (cRA) has been shown to reverse oral leukoplakia and to reduce the frequency of second primary tumours in patients treated for head and neck cancer. Since chemopreventive treatments must be of very long-term duration (even years), and because of apparent 'good health' of treated patients, the toxicity of used drugs and the compliance with treatment need to be carefully considered. Current clinical research has evaluated the efficacy of low doses of cRA in larger numbers of patients, and the increased effectiveness of cRA when used in combination with recombinant alpha-interferon 2a (r-alpha-IFN 2a) has also produced high objective response rate in patients affected with squamous cell carcinoma of the head and neck. In vitro and in vivo studies to verify the validity of several biomarkers (in particular micronuclei) as intermediate end-points in chemoprevention studies are continuing, to allow the short-term screening of promising chemopreventive drugs to be used in clinical trials. The published literature on this matter is reviewed, with special attention to retinoid treatment and toxicity/compliance-related problems, and compared with our own experience.

Carcinoma, Squamous Cell↗
PubMed1994

Neuropeptide Y in juvenile migraine and tension-type headache.

Neuropeptide Y (NPY) is widely distributed throughout sympathetic nerve endings where it is co-stored and co-secreted with noradrenaline. It is considered a marker of noradrenergic function. To determine the role of NPY in the pathogenesis of juvenile headache, we determined its plasma levels in two groups of young migraine patients (with and without aura), in a group of episodic tension-type headache patients and in a group of age and sex-matched healthy subjects. Significantly lower plasma levels of NPY were evident in the migraine patients with aura (P < 0.001) and, to a lesser extent, in the migraine patients without aura (P < 0.02), both assessed in the interictal period, with respect to the control group. Plasma NPY levels tended to significantly increase during attacks in migraine patients with aura (P < 0.0009). A less evident, though significant increase was also present during attacks in migraine patients without aura (P < 0.02). No significant variations were observed between headache-free periods and attacks in tension-type headache patients. Reduced NPY levels in the interictal period can be considered further evidence of the derangement of the sympathetic function in the course of migraine, particularly that with aura. The increase in NPY levels during migraine attacks could be an expression of sympathetic activation, even though the functional status of this system is less efficient.

Adolescent↗
PubMed1994

Endothelin 1 in migraine and tension-type headache.

We determined the plasma levels of ET1, both interictally and ictally, in 50 migraine patients, 20 with aura (MPA) and 30 without aura (MPWA), comparing them with the levels of 40 age-matched tension-type headache patients (20 episodic and 20 chronic) (ETTHP and CTTHP) and the levels of a group of 20 healthy control subjects (CS). No statistically significant difference was evident between the mean ET1 plasma levels of MPA and those of MPWA, assessed in headache-free periods. The mean ET1 plasma levels of MPA and MPWA, assessed interictally, were significantly higher than those of CS. However, the values of plasma ET1 in ETTP and in CTTHP did not differ statistically from those of CS. MPA and MPWA ET1 plasma levels increased significantly within 2 h from the onset of attacks (p < 0.0001) and remained significantly higher between 4 and 6 h from the onset. The ET1 plasma levels of ETTHP and CTTHP assessed during attacks did not differ statistically from those of the same patients assessed in the headache-free periods. The increase in ET1 levels in MPA and MPWA patients when assessed ictally, suggests that this peptide is involved in the haemodynamic changes and vascular tone modifications observed during migraine attacks, particularly in the first phase of the ictal period.

Adult↗
PubMed1994

Cultures of human embryonic osteoblasts. A new in vitro model for biocompatibility studies.

Cell populations derived from human embryonic bone were isolated according to the ability of osteoblasts to migrate from bone onto glass fragments. Morphologic and biochemical assays showed (1) osteoblast-like appearance; (2) elevated alkaline phosphatase 1,25(OH)2D3 responsive activity associated with plasma membranes and matrix vesicles; (3) production of a thick extracellular matrix, mainly composed of Type I collagen, which mineralized in the presence of 10 mM beta-glycerophosphate; and (4) higher growth rate and viability when compared with their mature counterpart. Cultures of embryonic cells were challenged with particles of several biomaterials, and their effects on morphology, vitality, and osteogenic capacity of the cultured cells were tested. Stainless steel, titanium alloy, Co-Cr-Mo alloy (vitallium), carbon fiber-reinforced polybutylene terephtalate, ultra-high molecular weight polyethylene, ceramic, calcium phosphate, and hydroxyapatite did not exert any significant deleterious effects on the cultured human osteoblasts.

Alkaline Phosphatase↗
PubMed1994

Neuropeptide Y plasma levels and serum dopamine-beta-hydroxylase activity in MS patients with and without abnormal cardiovascular reflexes.

An impairment in the autonomic function has been demonstrated in patients with multiple sclerosis (MS) using electrophysiological, pupillary and biochemical tests. Particularly evident were alterations in the cardiovascular reflexes, cutaneous sympathetic response and lymphomonocyte adrenergic binding. Electrophysiological and biochemical findings in MS patients have only occasionally been compared. Among the peripheral markers of the autonomic system, Neuropeptide Y (NPY) and dopamine-beta-hydroxylase (DBH) have been singled out as reliable indices of sympathetic function. The former is a peptide with a strong vasoconstrictive action, which is released from adrenergic endings together with noradrenaline following sympathetic activation. The latter is the enzyme which catalyses the conversion of dopamine to norepinephrine. It is located both in sympathetic endings and the chromaffin granules of adrenal medulla. To verify a failure in autonomic function in the course of MS, a battery of cardiovascular tests (assessing sympathetic and parasympathetic functions) was performed on 25 MS patients. The results were compared with a group of 20 age- and sex-matched control individuals. The plasma levels of NPY and the serum DBH activity were also determined in both groups. 52% of patients showed an impairment in sympathetic function in one or more tests (sustained handgrip, postural hypotension, cold face test). 48% of the patients had abnormal values in deep breathing test, indicating a failure of the parasympathetic function. 44% of patients showed also a paroxysmal tachycardia after cold face test, indicating an abnormal function of the vagal-cardiac and sympathetic-vascular smooth muscle pathways of the trigeminal nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effect of retinoic acid on osteocalcin gene expression in human osteoblasts.

It is well known that the expression of osteocalcin, the only recognized osteoblast-specific protein, is regulated by 1 alpha-25-dihydroxyvitamin D3 through a distinct vitamin D3 receptor and a cis-acting DNA response element. In addition, recent data obtained with plasmid constructs have shown a positive interaction between retinoic acid activated receptor(s) and the osteocalcin gene promoter. Our studies, carried out on primary cultures of human osteoblasts, have demonstrated for the first time the activation of the osteocalcin gene expression by retinoic acid. Moreover, a remarkable synergistic effect between the hormonal forms of vitamin A and D3 on the synthesis of this bone-specific protein was observed.

Calcitriol↗