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Biomedical subjects

R Giordano

Publications and source records attributed to R Giordano.

At least 109 records · Page 6Linked to original sources
PubMed1992

A successful two-step integrated protocol of anti-HBV vaccination in chronic uremia.

A prospective study was performed in 40 chronic uremics which included: (1) the intramuscular administration to all patients of 40 micrograms of a DNA-recombinant vaccine (Engerix-B) at 0, 1, 2, 6 months; (2) an intramuscular booster dose of 40 micrograms at 18 months in patients having an anti-HBs titer greater than 100 mIU/ml at the 7th month (group A); (3) a further intramuscular supplementary dose of 40 micrograms at 12 months (besides that at 18 months) in patients developing an antibody titer less than 100 mIU/ml at the 7th months (group B); (4) an intradermal course of 5 micrograms of vaccine every 2 weeks until the protective titer (greater than or equal to 10 mIU/ml) was achieved, and then every month for a total of 6 months in patients who did not develop a protective titer even after 19 months (group C). At the end of the study, all patients had developed a protective titer: 77.5% after the 4th intramuscular dose, 12.5% after the 5th and 10% after 3.5 +/- 0.5 (mean +/- SEM) intradermal inoculations. The mean antibody titers were 1,461 +/- 98 mIU/ml in group A, 594 +/- 684 in group B and 131 +/- 133 in group C. In conclusion, our two-step integrated protocol gives an anti-HBs protective titer in all our patients.

Female↗
PubMed1992

Bone mineral and aluminum concentrations in patients undergoing CAPD.

CAPD results in continuous peritoneal transfer of hormones and minerals involved in the pathogenesis of renal osteodystrophy (RO). Moreover, although CAPD patients seem to have better control of serum phosphate concentration than hemodialysis patients, the need for aluminum-containing phosphate binders (ACPB) may still be present. In a prospective study meant to investigate the evolution of RO, we obtained 79 bone biopsies in 29 uremic patients (20 male, 9 female; age 25-59, mean 46). Of these, 22 were obtained at the beginning of treatment, 24 after 24 months, 23 after 36 months and 10 after 60 months. All patients were treated with CAPD (Viaflex, Baxter 2-2.5 L x 4-5 bags/day; Ca(++) + 3.5, Mg(++) 1.5 mEq/L) as the first modality of therapy and received oral calcitriol, aluminum hydroxyde and/or calcium carbonate and magnesium hydroxyde in order to maintain serum calcium (Ca) and phosphorus within the normal range. Qualitative bone histology, bone Ca and magnesium (Mg) (Flame atomic absorption spectroscopy) and aluminum (Al) concentration (Graphite furnace atomic absorption spectrometry) were determined. CAPD achieves a good control of RO as indicated by the tendency toward a decreased incidence of mixed osteodystrophy and predominant hyperparathyroid bone disease and improvement of osteoid lesions. A defective Ca content of bone is persistent in the observed period and positively correlated to bone Mg concentration. An increased level of Al was shown in the serum and bone. The highest bone Al content was found among patients with predominant osteoid bone disease. Also in CAPD, patients consuming ACPB are at risk of bone Al accumulation despite the low Al levels in the dialysate.

Adult↗
PubMed1992

Inorganic element concentrations in cataractous human lenses.

We evaluated the presence of calcium, potassium, zinc, copper, and selenium in human lenses (53 cataractous and 10 clear lenses). The determinations of these elements were done using atomic absorption spectrometry techniques, namely flame and flameless methods, after acidic digestion of the samples. Compared with the results obtained from samples of normal lenses (zinc, 16.5 +/- 2.5 mg/kg dry weight; copper, 0.53 +/- 0.08 mg/kg dry weight; selenium, 0.83 +/- 0.18mg/kg dry weight; potassium, 10,306 +/- 1232mg/kg dry weight, and calcium, 9.9 +/- 2.7mg/kg dry weight), the mean concentration values of the cataractous lenses showed some significant changes. Increases were found for zinc, copper, and calcium; the potassium concentration decreased. No significant changes occurred in selenium values. A positive correlation was found between zinc and copper concentrations (y = 0.030x + 0.007, r = .79). An inverse correlation was evident between calcium and potassium values (y = -0.097x + 1141, r = -.65).

Aged↗
PubMed1991

Serum selenium concentration and disease progress in patients with HIV infection.

The selenium concentration in the serum of 67 patients with HIV infection was measured to determine whether selenium deficiency occurred in the different stages of the disease. In the first stage of the study, patients were divided into four groups: symptom-free subjects, PGL (persistent generalized lymphadenopathy), ARC (AIDS related complex), and AIDS (acquired immunodeficiency syndrome). Selenium concentrations were normal in HIV antibody positive symptom-free subjects (1.18 +/- 0.27 mumol/L) and lower than normal in the other three groups (p less than 0.001). There was a significant correlation (p less than 0.001) between selenium levels and values of hemoglobin and erythrocyte sedimentation rate. Selenium deficiency was in no case associated with a lack of zinc in serum (also determined in all patients). In the second stage of the study, 12 patients were treated for a period of two months with low doses of selenium to assess whether such supplementation was able to restore their impaired immunological and hematological functions. The therapy increased serum selenium concentrations (from 0.77 +/- 0.23 to 1.44 +/- 0.41 mumol/L) and symptomatic improvements were noted. However, no changes were observed in the immunological and hematological parameters.

Adult↗
PubMed1991

Congenital muscular dystrophy: brain alterations in an unselected series of Western patients.

The typical form of congenital muscular dystrophy (CMD) described in Western countries is generally considered different from its Japanese variant because of the absence of CNS involvement. Evaluations from both a clinical and a neuroradiological point of view were made of the CNS functions of 12 unselected Western children affected by CMD. In five patients, clinical observation and intelligence tests showed a mild to severe mental retardation. One of these patients suffered also from a severe form of epilepsy. In the same five patients, various degrees of white matter hypodensity, ventricular enlargement and cerebral atrophy were also detected. Similar neuroradiological abnormalities were also found in five of the seven children who did not have clinical symptoms or signs of CNS involvement. In one of these cases, necropsy neuropathological examination showed the gyral anomalies characteristic of the Japanese type of CMD. This study clearly indicates the high frequency of subclinical CNS alterations in typical Western CMD, suggesting that it should be considered a type of myoencephalopathy like its Japanese counterpart.

Adolescent↗
PubMed1990

Antioxidant enzymatic systems in neuronal and glial cell-enriched fractions of rat brain during aging.

The activities of Cu,Zn superoxide dismutase, glutathione peroxidase, catalase and glutathione reductase in neuronal and glial cell-enriched fractions obtained from the cerebral cortex of rat brain during aging (15, 30, 90, 350, 750 days of age) were assayed. Our results showed that glutathione peroxidase, catalase and glutathione reductase activities varied little during the examined periods. Only the Cu,Zn superoxide dismutase activity decreased notably from 15th to 750th day of age in both neuronal and glial cells, moreover the activities of all enzymes studied were always detected at lower levels in neuronal cells with respect to glial cells. In agreement with diminished SOD activity, the lipid peroxidation showed an elevated increase with aging; this fact is more evident in neuronal than in glial cells. In conclusion our data show that Cu,Zn superoxide dismutase is the most affected antioxidant enzymatic system of brain aging and it could be responsible for the increased lipid peroxidation in both cell types examined.

Aging↗
PubMed1990

Silver binding to Pseudomonas aeruginosa azurin.

The interaction between azurin and silver ions was investigated, by means of ultraviolet, fluorescence and atomic absorption spectroscopies, as a function of the redox state of the protein. The Ag(I) ion has a very low affinity for oxidized azurin. Interestingly, the affinity is much higher for reduced azurin; in this case Ag(I) completely displaces the Cu(I) ion from the native binding site. The effect is very specific for silver ions since other ions, such as Hg(II), Ni(II) and Cd(II), do not produce the same effect. Treatment of reduced and oxidized azurin with excess Ag(I) (2-8-fold stoichiometric) shows that there is a second binding site for silver ions on the protein which can also bind Cu(II) and Hg(II) with comparable affinities.

Azurin↗
PubMed1990

Experimental aluminum pathology in rabbits: effects of hydrophilic and lipophilic compounds.

Aluminum lactate [Al(lact)3] (hydrophilic, hydrolytically unstable) and aluminum acetylacetonate [Al(acae)3] (lipophilic, hydrolytically stable) were tested as potential toxicants to rabbits upon IV administration both as aqueous solutions and as liposome suspensions. Both chemicals behaved as cardiotoxic agents when administered as aqueous solutions, but Al(acae)3 was at least two orders of magnitude more active than Al(lact)3. Al(acae)3, but not Al(lact)3, caused myocardial infarcts resembling those in humans (with contraction bands) at doses as low as 0.24 mg/kg body weight, as well as a prominent acanthocytosis. Al(lact)3, when administered as a liposome suspension, was about 300 times more toxic than in aqueous solution, although cardiac damage was not infarctual in character. Both chemical and physical speciation of aluminum(III) thus play an essential role in determining the toxicity of the metal.

Aluminum↗
PubMed1989

Paraneoplastic syndrome in the course of Hodgkin disease. Case report.

A woman with Hodgkin disease presented a neoplastic syndrome of unusual magnitude affecting both the CNS and PNS. The severity of the clinical pattern contrasted strongly with the paucity of neuropathological findings. The report is followed by a brief discussion of the etiological and clinical problems of paraneoplastic syndromes affecting the nervous system.

Aged↗
PubMed1989

Gallium distribution in several human brain areas.

Gallium is an element of increasing biological interest: It is involved in problems related to environmental pollution (Ga compounds are used in electronics industry) and to clinical treatments (Ga radionuclides are employed to detect neoplastic lesions). Moreover, since its chemical behavior is similar to that of aluminum, gallium could play a role in the health effects attributed to this element. Data on naturally occurring Ga levels in human samples from healthy subjects are scanty; regarding the brain, the only reliable values available in the literature were published by Hamilton in 1972/73. In this work, the gallium distribution in several human brain areas, evaluated by radiochemical neutron activation analysis (RNAA), was found to be dishomogeneous. The element concentration determined in dry samples was, in any case, lower than the ppb level.

Brain Chemistry↗
PubMed1989

Distribution of aluminium following intraperitoneal injection of aluminium lactate in the rat.

An animal experiment was performed to evaluate the absorption and distribution of aluminium in serum and tissues of normal rats. The animals were intraperitoneally injected with an aluminium lactate solution at a pH adjusted to 7.0. Before starting, a short preliminary study was carried out in order to verify the validity of the treatment with aluminium lactate instead of aluminium chloride at endogenous pH 3.4. Thirty-one rats were used in the main experiment, divided in four groups. In treated animals, the total Al-administered dose was 75.6 mg during 78 days of treatment. Furthermore, to evaluate the influence of the parathyroid hormone on Al absorption and/or distribution, 200 USP/rat of parathyroid hormone extract (PTH) were also administered during the last 5 days of the experiment. Aluminium content in serum, tibia, rib, brain, liver, muscle, kidney and spleen was determined. Calcium analysis in serum and bone was also performed. The highest concentrations of aluminium were found in liver and spleen, whereas the lowest level was found in the brain. The PTH effect on Al absorption was evident in brain and bone.

Aluminum↗
PubMed1989

Predictive value of serum aluminium levels for bone accumulation in haemodialyzed patients.

Uremic patients undergoing long-term dialysis risk accumulating tissue aluminium burdens and developing aluminium-related syndromes, such as dialysis encephalopathy and osteomalacia. A statistical retrospective study on 253 uremic subjects was carried out to verify the predictive value of serum aluminium levels on bone aluminium accumulation. Serum and bone samples collected at the same time were analyzed for aluminium content. Analyses were performed by graphite furnace atomic absorption technique. The results verified bone aluminium concentrations of less than or equal to 60 mg/kg d.w. (dry weight) in 144 patients and greater concentrations in 109 patients. The statistical discriminant analysis showed that serum levels can be predictive in aluminium bone accumulation (lower or greater than 60 mg/kg) with about a 7% margin of error. This value may be further reduced to about 2% if two threshold limits are used (53-81 micrograms/l). The specificity and sensitivity of the test were 89.6% and 83.5%, respectively.

Aluminum↗
PubMed1989

Mercury, cadmium and lead levels in marine organisms (Mytilus galloprovincialis Lmk.) collected along the Italian coasts.

The growing importance assumed in the last ten years by contamination of the marine environment caused by heavy metals has evidenced the necessity to constantly deepen the knowledge of pollutant concentration that can reach man through the food chain. Particularly interesting is the determination of potentially toxic elements in marine organisms which through accumulation and concentration processes can provide a direct correlation with the ecosystem's degree of contamination. The present study takes into account the determination of mercury, cadmium and lead in samples of Mytilus galloprovincialis Lmk. collected in 41 sites along the Italian coast, between August 1986-April 1987. Analyses were performed using both the electrothermal (cadmium and lead) and the cold vapour (mercury) atomic absorption spectrometry techniques. Results showed that, in general, the degree of contamination is low, with a few exceptions where the concentration values were greater than the mean values.

Animals↗
PubMed1989

Experimental aluminum intoxication and parathormone: effects on the mineralization process.

In order to study the effect of aluminum intoxication on bone and bone cells in normal animals and its relationship with hyperparathyroidism, and so to obtain further data on a pathogenetic role of this condition in inducing osteomalacia in uremic patients, 31 rats divided in four groups were injected intraperitoneally for 11 weeks with: Al (75.6 mg); Al-PTH (Al = 75.6 mg + PTH = 200 USP during the last week); C (saline solution), and C-PTH (saline solution + PTH = 200 USP during the last week). Al injection induced a consistent increase in the element in serum and tibia. PTH administration further enhanced Al content in tibia. The trabecular bone surfaces of Al-administered rats were stained by aluminon; the endosteal borders of their compact bone were always negative. Rib histomorphometry showed absence of osteomalacia in Al group and increase in osteoid in Al-PTH group, with development of mild osteomalacia. In these groups osteoclasts were less numerous than in controls. Dynamic bone parameters showed no separation of double tetracycline labels in trabecular bone of both Al-administered groups. Cortical bone was only slightly affected by treatment. All these data indicate that Al alone, in the quantity administered, does not induce osteomalacia in normal rats and that PTH, although given for a few days, enhances Al content in bone and induces osteoid increment. The reduction of tetracycline labels in all Al-treated animals is due to reduction of calcification and formation rate, which might be an index of osteoblast inhibition. The decrease in the number of osteoclasts suggests that Al might inhibit their formation.

Aluminum↗
PubMed1989

Bone aluminum content in predialysis chronic renal failure and its relation with secondary hyperparathyroidism and 1,25(OH)2D3 treatment.

32 patients with slowly evolving predialysis chronic renal failure, who were not exposed to aluminum-containing antacids, were studied. A low aluminum intake was considered a useful condition to examine the bone deposition of the element as dependent variable, not interfering with PTH secretion and bone metabolism. Iliac bone biopsies for bone aluminum content and histomorphometric and histodynamic evaluations were taken. Serum aluminum, creatinine, calcium, phosphate, iPTH, osteocalcin (BGP), alkaline phosphatase (AP), 25-OHD3 and 1,25(OH)2D3 were also measured. 16 of the patients were on long-term treatment with 1,25(OH)2D3 (0.25 micrograms daily) for prevention and treatment of secondary hyperparathyroidism. Bone aluminum content of all patients showed a strong positive correlation with BGP and iPTH (p less than 0.001) while the correlation with serum creatinine was not significant. Multiregression analysis has singled out BGP as the most predictive variable of bone aluminum content (r2 = 0.419). The patients receiving 1,25(OH)2D3 had lower iPTH (p less than 0.01), lower bone aluminum content (p less than 0.05) and increased mineral apposition rate (p less than 0.05) compared to the untreated group. The results suggest that treatment with 1,25(OH)2D3 for long-term suppression of secondary hyperparathyroidism does not enhance aluminum accumulation in bone. The finding of lower bone aluminum together with increased mineral apposition rate, seems to indicate that 1,25(OH)2D3 is able to induce an osteoid mineralization process more selective against aluminum incorporation in bone than in case of more severe hyperparathyroidism and 1,25(OH)2D3 deficiency. At least in the present condition of low aluminum intake, 1,25(OH)2D3 may be considered to have protective effects on bone from aluminum deposition.

Adult↗