Biomedical subjects

P Borella

Publications and source records attributed to P Borella.

At least 37 records · Page 2Linked to original sources

PubMed1995

The use of non-radioactive chromium as an alternative to 51Cr in NK assay.

A novel method to measure target cell cytolysis based on the use of 'cold', non-radioactive chromium and on the determination of metal release by graphite furnace atomic absorption spectroscopy (FAAS) is proposed. Natural killer (NK) assays were performed by labelling target cells with chromium as Na2CrO4, and results were compared with those obtained by conventional overnight labelling with 51Cr of targets killed by the same effectors. The cytotoxic capacity of peripheral blood lymphocytes from healthy subjects was evaluated, and NK activity measured with both methods showed a good agreement at each of the tested effector to target cell ratios (between 100:1 and 1:1), with a high and significant coefficient of correlation (r = 0.931, p < 0.0001). The selection of the appropriate Cr concentrations for labelling target cells took into account both the sensitivity of our instrumentation and the possible toxic effects of the metal. A study of the effects of Cr on the cell line (K562) which is usually employed as a target in NK tests showed that Cr could have a detrimental effect on cellular function, with significant numbers of cells with depolarised mitochondria and reduced DNA synthesis after 24 h incubation using Cr levels higher than 15 mumol/l (780 micrograms/l). The method proposed here has a number of advantages, including the use of a non-radioactive tracer, limited costs, high sensitivity and reproducibility, and the possibility of storing samples. In addition, the technique uses a fixed Cr concentration which is known to be non toxic.

Adult↗

PubMed1995

Genetic heterogeneity in tubular hypomagnesemia-hypokalemia with hypocalcuria (Gitelman's syndrome).

To better clarify the genetic inheritance of primary tubular hypomagnesemia-hypokalemia with hypocalciuria, or Gitelman's syndrome (GS), we studied eight families (10 patients aged 11 to 22 years; 16 parents; 9 siblings) in which at least one offspring had GS (plasma magnesium < 0.65 mmol/liter; plasma potassium < 3.6 mmol/liter; high magnesium and potassium fractional excretions; molar urinary calcium/creatinine < 0.10). Two families each had two offspring of different sex with GS, who all had tetanic episodes and/or marked weakness during childhood or adolescence, whereas in three other families two mothers and three offspring presented GS and one father and two other offspring had hypomagnesemia and hypocalciuria but normal plasma potassium. The mean plasma magnesium and potassium levels of the patients of the first two families were significantly lower (P < 0.05) than those of the other three families. Intralymphocytic but not intraerythrocytic magnesium and potassium were significantly lower (P < 0.05) in patients compared to controls. We hypothesize that there are two different types of genetic transmission of GS, one autosomal recessive and one autosomal dominant with high phenotype variability. It seems that this genetic heterogeneity is associated with a different clinical expression with frequent tetanic episodes and lower plasma potassium and magnesium levels in the autosomal recessive form.

Adolescent↗

PubMed1995

Response to orthostatic stress predicts office-daytime blood pressure difference, but not nocturnal blood pressure fall in mild essential hypertensives: results of the harvest trial.

1. The aim of the present study was to evaluate whether postural blood pressure (BP) change could predict office-day-time BP disparity and the nocturnal BP fall in young, mild essential hypertensives. We investigated 411 males aged between 18 and 45 years with never treated borderline to mild hypertension. BP was measured three times after a 5 min rest in the supine position and thereafter three times after 2 min of standing. The mean of six BP measurements obtained during two visits in the lying position was defined as office BP. 2. Twenty-four hour ambulatory BP monitoring was performed with either the A&D TM-2420 model 7 or the ICR Spacelabs 90207. BP values were averaged for day- and night-time periods. The nocturnal BP fall was defined as the difference between the average day- and night-time BP. 3. The standing-lying difference was significantly inversely correlated with the office-daytime difference for both systolic blood pressure (SBP) (r = -0.34, P < 0.001) and diastolic blood pressure (DBP) (r = -0.24, P < 0.001). These correlations did not change when the obese subjects (body mass index > 30 kg/m2) were excluded from the analysis. No significant correlation between standing-lying difference and nocturnal BP fall was found. 4. Our results indicate that white coat hypertension assessed as the office-daytime BP disparity is partially related (in a negative fashion) to the BP reaction to standing. The postural BP change does not predict nocturnal BP fall in young, mild essential hypertensives.

Adult↗

PubMed1994

Trace elements in saliva and dental caries in young adults.

The results of a study on Zn, Cu, Ca and Mg content in whole saliva and supernatant of young adults in relation to caries prevalence are reported. A total of 225 university students were selected for the study on the basis of voluntary participation. The salivary electrolytes showed a high intersubjective variability and females had significantly lower levels than males. In whole saliva, the trace elements were highly correlated, whereas the correlations were weaker in the supernatant. The ratio supernatant/whole saliva varied between subjects and according to the examined electrolytes. No association could be found between the measured trace elements and DMFT. When we analysed the relation with recent caries experience in the subgroup of subjects undergoing oral examinations for at least 1 year, we found evidence that the Zn/Cu molar ratios in whole saliva were significantly decreased in subjects with more than three decayed teeth compared with those with no caries (1.54 vs. 1.11, P < 0.05). No significant association was found when supernatant was analysed. We conclude that the electrolytes' levels in whole saliva might be more adequate than the levels in supernatant to evaluate the relationship with caries.

Adolescent↗

PubMed1994

Zinc and magnesium in liver cirrhosis.

The Authors determined zinc (Zn) and magnesium (Mg) in the plasma, urine, erythrocytes (RBCs), mono- and polymorphonuclear cells (MNCs and PMNs) of patients with overt alcoholic and non-alcoholic liver cirrhosis. In order to obtain a clearer clinical picture, biochemical and nutritional parameters (retinol, tocopherol, six different carotenoids, creatinine-height index and tricipital skinfold), as well as markers of portal hypertension (spleno-portal size and platelet count) were also evaluated. The plasma levels of Zn and Mg were found to be reduced, as were the urine levels of Mg. Urine Zn, on the other hand, was higher than normal. Plasma Zn correlated inversely, and urine Zn directly, with the severity of the disease, rather than with alcohol consumption or treatment with diuretics. Protein metabolism impairment would appear to affect the plasma transport of Zn rather than its overall availability in the organism; the opposite was found in the case of Mg, the availability of which appeared to be reduced. Determination of the two elements in RBCs, MNCs and PMNs suggested that a true nutritional deficit cannot be demonstrated. MNCs, rather than RBCs or PMNs seem better to reflect tissue status of trace elements.

Erythrocytes↗

PubMed1993

Effects of trace elements on immune system: results in cultured human lymphocytes.

We have studied the effects of lead, cadmium and hexavalent chromium in cultured human lymphocytes. Both the proliferative response and the generation of antibodies were evaluated, and the metal accumulation in the cells was measured. Lead added in the range of human exposure caused a significant enhancement in Ig production, which was related to the Pb concentration in the cells. An inhibitory effect on blastogenesis, was detected at Cd doses found in occupationally exposed subjects. Chromium induced reductions in both blastogenesis and Ig production in relation to its capability to enter the cells.

Analysis of Variance↗

PubMed1993

Is magnesium content in erythrocytes suitable for evaluating cation retention after oral physiological supplementation in marginally magnesium-deficient subjects?

In this study, the effects of oral magnesium supplementation were evaluated on plasma, erythrocyte, and urinary cation levels. The study was carried out with an open, cross-over and randomized design. Healthy subjects received two sachets per day of magnesium (366 mg Mg2+/d) for two 28 d cycles, separated by a 3-week washout interval. Magnesium concentrations were measured before the supplementation and at weekly intervals during the treatment. Urinary excretion of Mg was significantly increased during supplementation, with no differences among the weeks examined. Only small increases in plasma magnesium occurred, and values returned to the prestudy levels before the end of supplementation. The increase in erythrocyte magnesium, however, was statistically significant; this trend suggests the existence of a saturable mechanisms, which prevents any possible magnesium overload during oral supplementation. We conclude that erythrocytes might be considered a suitable index for evaluating the bioavailability of magnesium salts in marginally magnesium-deficient subjects.

Administration, Oral↗

PubMed1992

Oral magnesium supplementation improves fetal circulation.

It is well known that pregnancy is a condition in which plasma magnesium falls because of accumulation of the ion in the placenta and fetus. Magnesium (Mg) is therefore widely given as a supplement during pregnancy, particularly in cases of preterm labour. In our experience, the combination of oral Mg (magnesium pyrrolidone carboxylic acid) at a dose of 360 mg/day with conventional ritodrine treatment allows a reduction in ritodrine dosage, accompanied by a significant reduction in side effects. We therefore evaluated changes in fetal blood flow, using pulsed Doppler, in women submitted to combined magnesium and ritodrine treatment compared to those treated with ritodrine plus placebo. The Mg-treated group showed a decrease in vessel resistance both in the umbilical artery and in the fetal middle cerebral artery, indicating that fetal vasculature is sensitive to exogenous Mg. Measurement of plasma and mononuclear cell Mg showed an intracellular increase in the cation of about 10 per cent. We conclude that oral magnesium supplementation in pregnancy is safe and that it has a positive effect on the fetal circulation.

Cerebral Arteries↗

PubMed1991

Lead and cadmium at very low doses affect in vitro immune response of human lymphocytes.

The effect of lead chloride and cadmium chloride on in vitro immunoglobulin (Ig) production by human lymphocytes was investigated. After 7 days in culture, lead added in the range of human exposure (207-1035 micrograms/liter) significantly enhanced Ig production either when cells were activated by pokeweed mitogen (PWM) or not. The effect was dose-dependent and was related to the Pb we measured in the extracellular medium and in the cells. Independently of the mitogen addition, about 2% of the Pb added was accumulated in the cells, most being associated with the nuclear fraction. Those findings suggest that the Pb effects could depend on its uptake and distribution in the cells. Cadmium added in the 50-500 nM range exhibited a dose-independent mitogenic activity in unstimulated cells, whereas the Ig secretion was not significantly affected by Cd when cells were PWM-activated. A considerable intraindividual variability, however, was observed when blood donors were separately examined, with both an increase, a decrease, or no variation on Ig production. Furthermore, higher percentages of Cd were accumulated in the nuclear fraction, and lower in the cytosol and precipitate, in PWM-activated compared to resting lymphocytes. Genetic factors could be of importance for the observed variability of the immune response to cadmium, and we support the hypothesis that differences in the metallothionein (MT) inducibility could play a role.

Adolescent↗

PubMed1991

Magnesium prophylaxis of menstrual migraine: effects on intracellular magnesium.

The effects of oral Magnesium (Mg) pyrrolidone carboxylic acid were evaluated in 20 patients affected by menstrual migraine, in a double-blind, placebo controlled study. After a two cycles run-in period, the treatment (360 mg/day of Mg or placebo) started on the 15th day of the cycle and continued till the next menses, for two months. Oral Mg was then supplemented in an open design for the next two months. At the 2nd month, the Pain Total Index was decreased by both Placebo and Mg, with patients receiving active drug showing the lowest values (P less than 0.03). The number of days with headache was reduced only in the patients on active drug. Mg treatment also improved premenstrual complaints, as demonstrated by the significant reduction of Menstrual Distress Questionnaire (MDQ) scores. The reduction of PTI and MDQ scores was observed also at the 4th month of treatment, when Mg was supplemented in all the patients. Intracellular Mg++ levels in patients with menstrual migraine were reduced compared to controls. During oral Mg treatment, the Mg++ content of Lymphocytes (LC) and Polymorphonucleated cells (PMN) significantly increased, while no changes in plasma or Red Blood Cells were found. An inverse correlation between PTI and Mg++ content in PMN was demonstrated. These data point to magnesium supplementation as a further means for menstrual migraine prophylaxis, and support the possibility that a lower migraine threshold could be related to magnesium deficiency.

Administration, Oral↗

PubMed1991

Oral magnesium successfully relieves premenstrual mood changes.

Reduced magnesium (Mg) levels have been reported in women affected by premenstrual syndrome (PMS). To evaluate the effects of an oral Mg preparation on premenstrual symptoms, we studied, by a double-blind, randomized design, 32 women (24-39 years old) with PMS confirmed by the Moos Menstrual Distress Questionnaire. After 2 months of baseline recording, the subjects were randomly assigned to placebo or Mg for two cycles. In the next two cycles, both groups received Mg. Magnesium pyrrolidone carboxylic acid (360 mg Mg) or placebo was administered three times a day, from the 15th day of the menstrual cycle to the onset of menstrual flow. Blood samples for Mg measurement were drawn premenstrually, during the baseline period, and in the second and fourth months of treatment. The Menstrual Distress Questionnaire score of the cluster "pain" was significantly reduced during the second month in both groups, whereas Mg treatment significantly affected both the total Menstrual Distress Questionnaire score and the cluster "negative affect." In the second month, the women assigned to treatment showed a significant increase in Mg in lymphocytes and polymorphonuclear cells, whereas no changes were observed in plasma and erythrocytes. These data indicate that Mg supplementation could represent an effective treatment of premenstrual symptoms related to mood changes.

Administration, Oral↗

PubMed1990

Maternal plasma concentrations of magnesium, calcium, zinc and copper in normal and pathological pregnancies.

In this study, plasma levels of magnesium, calcium, zinc and copper were simultaneously determined in pregnancies complicated by either abortion, intrauterine growth retardation (IUGR), diabetes or EPH (edema, proteinuria, hypertension) gestosis. The levels of the four cations in non-pregnant women and in healthy, pregnant women were also determined. Compared with controls, a significant decrease in magnesium, with increase of the Ca/Mg ratio, was found in spontaneous abortions, but not when patients had a successful continuation of pregnancy. In EPH gestosis, total calcium was reduced, with a significant decrease of the plasma Ca/Mg ratio. A slight, but significant, increase in plasma zinc was observed in women affected by either diabetes or IUGR, probably as a result of reduced zinc uptake by the fetus. In addition, higher copper levels were found in the pathologies studied, with the exception of missed abortions. The possible role of an altered Ca/Mg ratio homeostasis in relation to gestational pathologies is discussed.

Abortion, Spontaneous↗

PubMed1990

Magnesium and potassium status in elderly subjects with and without dementia of the Alzheimer type.

Magnesium status was evaluated in healthy elderly people, and in patients affected from dementia of the Alzheimer type. Magnesium levels were determined in plasma, erythrocytes (RBC), lymphocytes (MNC), and granulocytes (PMN), and were compared with measurements in young healthy adults. Significantly lower plasma Mg concentrations were found in elderly people compared to controls, with no difference between cognitively normal and demented subjects. Mg levels in healthy elderly people were higher in MNC and lower in PMN, compared to the younger group. No difference was observed between demented patients and young controls in Mg content of white blood cells, but the patients had higher Mg/K ratios. In addition, significant correlations were found between cognitive impairment and the Mg/K ratio in MNC. When we assessed the philothermal response of granulocytes, a significant correlation was observed in demented subjects between the migration rate of PMNs and the PMN Mg/K ratio.

Aged↗

PubMed1990

Cadmium, nickel, chromium and lead accumulate in human lymphocytes and interfere with PHA-induced proliferation.

The in vitro effect of five toxic metals (cadmium, lead, nickel, barium, chromium III and VI) on PHA-induced blastogenesis in human lymphocytes was investigated by [3H]-thymidine incorporation. With the exception of hexavalent chromium, the metals tested were in the chloride forms. The levels of metals associated with lymphocytes were measured under our experimental procedure. An inhibitory effect was found when cadmium was added at doses which closely approximate those of occupationally exposed subjects. Hexavalent chromium and nickel showed a biphasic pattern, with a stimulatory effect at the lowest concentrations tested (10(-8)-10(-6) mol/L) and an inhibitory effect on thymidine incorporation at concentrations higher than 10(-6) and 10(-4) mol/L, respectively. No effect was observed when lead, barium, and trivalent chromium were added to the culture medium. All metals showed the ability to enter the lymphocytes or to adhere to their surface, and the interaction appeared to be quite stable, with the exception of barium. The relationship between metal accumulation and [3H]-thymidine incorporation in the cells is discussed.

Adult↗

PubMed1989

Intra-uterine growth retardation is associated with increased levels of magnesium in amniotic fluid.

Magnesium (Mg) and zinc (Zn) levels were measured in amniotic fluid of 30 normal pregnancies between the 16th and the 42nd week of amenorrhea and in 15 cases of intra-uterine growth retardation (IUGR) at 30-38th week of pregnancy. While Zn levels were stable throughout physiological pregnancy, the Mg concentration decreased progressively from 1.09 +/- 0.31 mg/100 ml (mean +/- SD) at the end of the second trimester to 0.75 +/- 0.20 (p less than 0.02) at term. In the case of IUGR, Mg levels (1.22 +/- 0.28) were higher than in controls (0.89 +/- 0.27, p less than 0.01) matched for gestational age. No differences in Zn levels were found between the two groups. Although the mechanisms leading to Mg accumulation in the amniotic fluid of growth-retarded fetuses remain unknown, these data support the role played by Mg in fetal growth.

Amniotic Fluid↗

PubMed1989

Relationship between lead exposure indicators and neuropsychological performance in children.

This study surveyed 237 schoolchildren in a lead-polluted industrial area in northern Italy to assess the relationship between various biological indicators (lead in blood, hair and teeth, and delta-aminolevulinic dehydratase [ALA-D] activity) and some neuropsychological functions, assessed by a battery of five psychometric tests. The geometric means of lead measured in blood, hair and teeth were 10.99 micrograms/dl, 6.79 micrograms/g and 6.05 micrograms/g, respectively. Mean ALA-D activity was 51 mU/ml RBC. By analysis of covariance, after regressing out the variance accountable to confounding variables (age, sex, occupation/education of parents), Total and Verbal WISC-R IQ and Toulouse Pieron test results were significantly affected by the levels of lead in teeth. ALA-D values also appeared to be related to WISC-R IQ results (Total, Verbal and Performance).

Child↗

PubMed1989

Cadmium in blood, urine and hair related to human hypertension.

A case-control study was performed to assess whether cadmium is related to hypertension in a non-occupationally exposed population. 63 male subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 63 male normotensive controls individually matched for sex, age, body mass index, smoking habits and work activities. Cadmium in blood, zinc and copper in serum, the three elements in urine and hair, together with some biological parameters involved in pathogenesis of hypertension, were investigated. The mean Cd blood value in hypertensives (H) was 0.58 micrograms/L vs 0.44 micrograms/L in normotensives (N) (t = 2.03; p less than 0.05) with a greater difference in non-smokers (0.41 micrograms/L vs 0.25 micrograms/L) (t = 2.69, p less than 0.01). Furthermore, both systolic and diastolic blood pressure were significantly related to cadmium blood levels (r = 0.20 and 0.19 respectively, p less than 0.05). Smoking habit affected cadmium levels only in the blood, not in the other biological matrices examined. No significant difference of cadmium content in urine and hair was found between normotensives and hypertensives but Cd/Cu ratio in urine was significantly lowered in the second group.

Adult↗

PubMed1988

Premenstrual increase of intracellular magnesium levels in women with ovulatory, asymptomatic menstrual cycles.

Intracellular magnesium (Mg) levels regulate several enzymatic reactions and the hypoactivity of Mg has been involved in different pathological states. In addition to other factors, gonadal hormones, too, have been found to interfere in Mg balance. This study evaluates the changes in Mg in women throughout the normal menstrual cycle and those measured at weekly intervals in males. Magnesium and potassium (K) levels were measured in the plasma, red blood cells (RBC), lymphocytes (LC) and polymorphonucleated cells (PMN) of 11 normal menstruating women, in different periods of their menstrual cycle. Blood samples were collected every 4th day. According to the time and LH, progesterone and estradiol levels, they were classed as follicular (Foll), periovulatory (OV), luteal (Lut) or premenstrual (PM). The Menstrual Distress Questionnaire completed by the subjects revealed that no significant symptomatology was present. Four blood samples were also collected from 4 normal males, at weekly intervals. Mg and K were determined by atomic absorption spectrophotometry. LC and PMN were purified by centrifugation on a Ficoll discontinuous gradient. No differences were found in males versus females in the Mg or K contents in the different compartments. In the 4 periods tested, the K levels were constant, in both females and males. The same applies for Mg contents in males. In females, Mg contents, as well as the Mg/K ratio in LC and PMN, showed a significant increase in the premenstrual period compared with the other periods of the cycle. On the contrary, plasma and RBC Mg levels were constant throughout the cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗