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Biomedical subjects

A Bertoli

Publications and source records attributed to A Bertoli.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of drug-resistance mutations in HIV-1 isolates from non-HAART and HAART treated patients in Burkina Faso.

Non-B HIV subtypes have been estimated to account for 88% of HIV infections in the world. These subtypes are particularly relevant in view of the availability of antiretroviral (ARV) drugs, since subtype-specific mutations are associated with drug-resistance in developing countries. Therefore, the pol gene sequences in HIV-1 isolates were examined from the three distinct groups of 39 infected patients from Ouagadougou in Burkina Faso: 17 patients who had not received any antiretroviral therapy (ART); 16 patients received ART, and 6 HIV-infected children, from infected mothers, received a single Nevirapine dose prophylaxis during birth. HIV-1 pol sequencing was successful for 29 samples. As expected, all patients presented the common (non-B subtype) M36I polymorphism and 26/29 (90%) the K20I mutation. Phylogenetic studies showed high predominance of recombinant HIV-1 strains: CRF06_cpx 16/29 (55.17%), CRF02_AG 9/29 (31.03%), A1 2/29 (6.89%), G 1/29 (3.44%), and CRF09_cpx 1/29 (3.44%). Two twins showed, 6 months after birth, a NNRTI-mutation (Y181C/Y). During the same period, the twin mother presented a different NNRTI-mutation (V106I), thus suggesting that the different blood drug concentration may determine a different drug-resistance pathway. Among 17 non-highly active antiretroviral therapy (HAART) patients, 3/17 (17.64%) presented virus with reverse transcriptase (RT) mutations [V118I: 1/17 patients (5.88%), V179E: 2/17 patients (11.76%)]. 10/17 (58.82%) presented virus with minor protease (PR) mutations [L63P: 5/17 patients (29.41%), V77I: 3/17 patients (17.64%), L10I: 2/17 patients (11.76%)]. 4/17 patients did not show any PR and RT mutations (23.52%). Among six HAART-treated patients, 6/6 and 3/6 had M36I and L63LP protease minor subtypes, respectively; and only two (33.33%) presented virus with K103N mutation. The low prevalence of drug-resistant associated mutations in Burkina Faso is encouraging. However, further studies with a larger cohort with a high non-B subtype prevalence are necessary to optimize ART in developing countries.

Adult↗
PubMed2005

Transient increase of plasma ghrelin after laparoscopic adjustable gastric banding in morbid obesity.

Ghrelin is a peptide hormone with orexigenic properties that is produced by the stomach. Ghrelin and leptin are thought to be the main regulators of appetite and body weight. The present study was aimed at evaluating the effect of weight reduction after laparoscopic adjustable gastric banding (LAGB) on metabolic parameters and energy balance regulatory peptides. Patients were evaluated before and 6, 12, 24 or 36 months after the procedure, and a blood sample was obtained. Ghrelin rose 6 and 12 months after LABG, and then returned to near-baseline levels. In our study, the correlation between ghrelin and BMI was weak, but a strong significant correlation was maintained between leptin and BMI. We conclude that ghrelin is mainly stimulated by the negative caloric balance, and hypothesize that ghrelin is involved in maintaining a stable body weight, while leptin signals the body energy store; both hormones together are part of a more complex feedback mechanism.

Adult↗
PubMed2004

Determination of 1-phenylazo-2-naphthol (Sudan I) in chilli powder and in chilli-containing food products by GPC clean-up and HPLC with LC/MS confirmation.

A simple and rapid method is reported for the routine determination 1-phenylazo-2-naphthol (Sudan I) in chilli powder and in chilli-containing food products. The method involved Soxtec extraction from the products followed by high-pressure gel permeation chromatographic clean-up collecting the appropriate fraction. Analysis of this fraction was by HPLC with UV/VIS detection. The limit of detection was 7 microg kg(-1) and the limit of quantification was 13 microg kg(-1). The identity of Sudan I in food products was established by electrospray LC/MS with MS/MS confirmation. From a small survey of 30 retail samples, 11 samples of crushed chilli, Italian pasta, chilli-snack and vegetable sauce contained levels of Sudan I ranging from 24 to 5591 microg kg(-1).

Capsicum↗
PubMed2004

Temporal change in the use of genotypic resistance testing over the years 1999--2003.

The evaluation of resistance test perception by clinicians over the years 1999--2003 was assessed in an Italian cohort. The results on 2233 samples from 1416 HIV-1 infected patients show an increase in HIV-1 drug resistance test requests over time, with a plateau reached in the last three years. CD4-cell count at the time of genotype request progressively increased. In particular, the median CD4 cell count of drug-treated patients increased from 221x10(6) cells/l [interquartile range (IQR): 109-368] in 1999 to 296x10(6) cells/l (IQR: 166-478) in 2003 (p<0.0001). At the same time, plasma HIV-RNA level progressively decreased from a median of 103,500 copies/ml (IQR: 37,250-260,000) in 1999 to 9,444 copies/ml (IQR: 2,086-41,281) in 2003 (p<0.0001). Overall, data suggest that the genotype test is increasingly considered, and requested also for patients at earlier stages of drug history and/or at less severe disease stage.

Anti-HIV Agents↗
PubMed2003

The effect of physical activities of various intensities on the energy expenditure of type 2 diabetic men.

Interventions that focus on changing lifestyles through the combined use of dietary management, weight reduction, and increased physical activity are essential for managing type 2 diabetes mellitus (T2DM). The objective of the present study was to examine mildly obese T2DM patients [ n=10; mean age (+/-SD), 51.29+/-6.80 years; body mass index (BMI), 30.26+/-6.19 kg/m(2); and glycosylated haemoglobin (HbA(1c)), 8.16+/-1.16%)] and to compare them with normoglycaemic persons ( n=10; age, 53.00+/-9.48 years; BMI, 27.63+/-3.33 kg/m(2), and HbA(1c), 5.85+/-0.56%) in terms of energy expenditure while performing physical activities of various intensities (i. e. light, moderate, and heavy). The resting metabolic rate for T2DM patients was significantly higher than that for healthy controls (2200+/-354 kcal/day vs. 1628+/-176 kcal/day, respectively; p<0.0001). The values of energy expenditure at all three levels of physical activity were comparable between the two groups. Physical activity seems to have various beneficial effects on mildly obese T2DM patients because it increases the plasma glucose consumption, resulting in similar energy expenditure in comparison with normoglycaemic individuals.

Adult↗
PubMed2003

Lipid profile, BMI, body fat distribution, and aerobic fitness in men with metabolic syndrome.

Obesity, impaired glucose tolerance, type 2 diabetes, hyperlipidemia, hypertension, and insulin resistance are wellknown components of metabolic syndrome and are associated to increased cardiovascular morbidity. The present study aimed to evaluate the relationships between cardiorespiratory fitness, body fat distribution, and selected coronary heart disease risk factors. A total of 22 untrained subjects affected by one or more features of metabolic syndrome and without clinical history of cardiovascular disease were studied. Nondiabetic subjects underwent an oral glucose tolerance test for glucose and insulin measurement; fasting glucose and insulin were measured in diabetic patients. Complete lipid profile, thyroid hormones, and thyroid-stimulating hormone were measured in all subjects. Basal energy expenditure and cardiorespiratory fitness were measured using a K4 analyzer. Cardiorespiratory fitness ( VO(2max)/kg) was assessed using a treadmill graded exercise test. Peak aerobic capacity ( VO(2max)/kg) was predicted by body fat distribution, insulin sensitivity index, and high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol ( p<0.001). A significant relationship was found between cardiorespiratory fitness ( VO(2max)/kg) and body mass index (BMI), insulin sensitivity index, and LDL cholesterol ( r=0.60, p<0.05; r=0.66, p<0.01 and r=0.54, p<0.05, respectively). Data demonstrated that aerobic fitness is related to metabolic parameters and to body fat distribution, and suggest that its modification may improve well-known predictors of coronary artery disease.

Adipose Tissue↗
PubMed2003

Morbid obesity: evaluation of metabolic indexes after adjustable silicone gastric banding.

Morbid obesity is frequently associated with other characteristics of metabolic syndrome and is related to an increased risk of cardiovascular disease. This study aimed at evaluating time-course changes in body weight, body mass index (BMI), insulin sensitivity indexes and lipid profile in severely obese patients who underwent adjustable silicone gastric banding. We studied 19 obese subjects before and 6-36 months after surgery. An oral glucose tolerance test was performed in all non-diabetic patients. All subjects were evaluated using insulin sensitivity indexes (ISI-HOMA and QUICKI), lipid profile, and anthropometric parameters (WHR, WC, BMI), and body composition was assessed with bioelectrical impedance analysis (BIA). Most of the weight reduction occurred within the first 6-12 months, followed by near stabilisation or even weight regain. We found a significant decrease in fasting insulin, improvement in waist-hip ratio, reduction in BMI and fat mass percent. We observed an improvement in insulin sensitivity evaluated by means of ISI-HOMA and QUICKI. Bariatric surgery was an effective therapeutic approach for these obese patients because it reduced both weight and insulin resistance, along with improving metabolic parameters. Improvement in metabolic parameters appears to precede body weight reduction.

Adolescent↗
PubMed2002

Effect of subclinical hypothyroidism and obesity on whole-body and regional bone mineral content.

OBJECTIVE: The present investigation was aimed to evaluate the effect of subclinical hypothyroidism and obesity on bone mineral content (BMC) in different body segments. METHODS: Thirty-two premenopausal women (age: 37 +/- 9.9 years), with a wide range in body mass index (BMI), were studied. Subclinical hypothyroidism was defined by a basal TSH > or = 4 microU/l and/or a TRH-stimulated peak > or = 30 microU/l. For each subject, weight, height, BMI (weight/height(2)) and the waist/hip ratio were measured. Total BMC, total bone mineral density (BMD), leg BMC, leg BMD, trunk BMC, trunk BMD, arm BMC and arm BMD were determined using dual-energy X-ray absorptiometry. Thyroid function (basal and TRH-stimulated TSH, free T(3) and free T(4)) were determined from fasting blood samples for all subjects. RESULTS: Anova was conducted within all the groups to observe the effect of thyroid status and/or obesity on BMC and BMD. There was no statistical difference for age. Total BMC was affected by obesity (p < 0.05) but not by thyroid status, BMD of the legs was significantly influenced both by thyroid function and obesity (p < 0.01); total BMD was affected by hypothyroid status (p < 0.05). A direct relationship between leg BMD and TSH was demonstrated. CONCLUSION: Subclinical thyroid hypofunction and obesity seem to affect BMD differently in the body segments. An influence of gravitational force seems necessary in order to make evident the effect of subclinical hypothyroidism on bone. A condition of subclinical hypothyroidism should be considered when evaluating subjects for osteoporosis, since a BMD measured at the femoral neck may induce underestimation of initial osteoporosis.

Absorptiometry, Photon↗
PubMed2001

Secondary mutations in the protease region of human immunodeficiency virus and virologic failure in drug-naive patients treated with protease inhibitor-based therapy.

The role of mutations in protease (PR) and reverse-transcriptase (RT) of human immunodeficiency virus (HIV) in predicting virologic failure was assessed in 248 antiretroviral-naive HIV-positive patients who began a PR inhibitor-containing antiretroviral regimen. Genotypic testing was performed on plasma samples stored before the start of therapy. Twenty-seven patients (10.9%) had mutations in the RT, 5 (2%) carried primary mutations in the PR, and 131 (52.8%) showed only secondary PR mutations. Virologic failure at week 24 occurred in 62 (25.0%) of 248 patients. There was a statistically significant correlation between virologic failure and the number of PR mutations (P= .04, chi(2) test). Mutations at codons 10 and 36 of PR (present in 39.3% and 40.0% of patients in whom treatment failed, respectively) were identified by stepwise logistic regression as the strongest predictors of virologic failure (odds ratio, 2.20; 95% confidence interval, 1.30-3.75; P= .004). If confirmed in independent studies, this result may justify the increased use of HIV genotyping in drug-naive patients requiring antiretroviral therapy.

Acute Disease↗
PubMed2001

Increasing prevalence of non-clade B HIV-1 strains in heterosexual men and women, as monitored by analysis of reverse transcriptase and protease sequences.

OBJECTIVE: We evaluated the prevalence of HIV-1 non-clade B over time in a formerly clade B-restricted area. Protease and reverse transcriptase regions of the pol gene were used for phylogenetic and recombination analysis and for clade assignment to HIV-1 A-D, F-H, J, and K strains of the M group. METHODS: The pol gene of 349 HIV-1 patients belonging to the Italian Cohort Naive for Antiretrovirals (ICONA) were genotypically analyzed to study the prevalence of antiretroviral-associated resistance mutations. All HIV-1 pol sequences and 32 HIV reference strains were analyzed, including the reference strains for the major HIV-1 subtypes. The non-clade B sequences according to the HIV-1 Subtyping Tool program were further studied by a bootscan analysis (SimPlot) to investigate the likelihood of recombination between subtypes. RESULTS: Phylogenetic analysis detected 19 of 349 (5.4%) non-clade B subtypes. The proportions of patients carrying non-clade B virus before and after 1997 were 1.9% and 8.4%, respectively (p =.008). Among whites, heterosexual infection and female gender were significantly associated with the presence of non-clade B subtypes (p =.001 and.005, respectively). Non-clade B HIV-1 was harbored by 14.5% of the heterosexuals who were found to be HIV-1 positive after 1997, 60% of whom were women. Bootscan analysis identified four strains as F, two as A, one as C, one as G, and 11 (57.9 %) as non-clade B recombinant subtypes. CONCLUSION: Detection of HIV-1 subtypes and intersubtype recombinants in a previously clade B-homogeneous area indicates that the HIV-1 epidemic is evolving in Italy and that heterosexuals and women are at increased risk of infection with non-clade B HIV-1 subtypes. Sequences inferred from the pol gene yield to establish the subtype of circulating HIV-1 strains. As a consequence, genotyping of pol gene for testing resistance to antiretrovirals warrants concomitant surveillance of non-clade B subtypes.

Adult↗
PubMed2001

Quinolizidine alkaloids from Genista ephedroides.

Alkaloids retamine, anagyrine, lupanine, 17-oxoretamine, 12-alpha-hydroxylupanine were detected, along with four others unidentified compounds in the aerial parts of Genista ephedroides D.C.

Journal Article↗
PubMed2001

The metabolism and imaging in live cells of the bovine prion protein in its native form or carrying single amino acid substitutions.

Prion diseases are probably caused by an abnormal form of a cellular glycoprotein, the prion protein. Recent evidence suggests that the prion strain causing BSE has been transmitted to humans, thereby provoking a variant form of Creutzfeldt-Jacob disease. In this work, we analyzed the behavior of normal and malformed isoforms of the bovine PrP in transfected mammalian cell lines. Biochemical and immunocytochemical assays were complimented with imaging of live cells expressing fusion constructs between PrP and GFP. Bovine homologues of human E200K and D178N (129M) mutations were used as models of pathogenic isoforms. We show that the GFP does not impair the metabolism of native and mutant bPrPs and is thus a valid marker of PrP cellular distribution. We also show that each amino acid replacement provokes alterations in the cell sorting and processing of bPrP. These are different from those ascribed to both murine mutant homologues. However, human and bovine PrPs carrying the D178N genotype had similar cellular behavior.

Amino Acid Substitution↗
PubMed2000

Bovine prion protein as a modulator of protein kinase CK2.

On the basis of far-Western blot and plasmon resonance (BIAcore) experiments, we show here that recombinant bovine prion protein (bPrP) (25-242) strongly interacts with the catalytic alpha/alpha' subunits of protein kinase CK2 (also termed 'casein kinase 2'). This association leads to increased phosphotransferase activity of CK2alpha, tested on calmodulin or specific peptides as substrate. We also show that bPrP counteracts the inhibition of calmodulin phosphorylation promoted by the regulatory beta subunits of CK2. A truncated form of bPrP encompassing the C-terminal domain (residues 105-242) interacts with CK2 but does not affect its catalytic activity. The opposite is found with the N-terminal fragment of bPrP (residues 25-116), although the stimulation of catalysis is less efficient than with full-size bPrP. These results disclose the potential of the PrP to modulate the activity of CK2, a pleiotropic protein kinase that is particularly abundant in the brain.

Animals↗
PubMed2000

Susceptibility of the prion protein to enzymic phosphorylation.

Ten protein kinases have been assayed for their ability to phosphorylate in vitro the recombinant bovine PrP (25-242) (rbPrP). Substantial phosphorylation was observed with PKC, CK2, and two tyrosine kinases, Lyn and c-Fgr. With regard to CK2, phosphorylation occurs at Ser 154 with a stoichiometry of about 0.1 mol phosphate/mol rbPrP, which is doubled by mild heat treatment of rbPrP. Heat also reduces the overall protein ellipticity, suggesting that reversibly unfolded conformers are more susceptible to phosphorylation. Our data disclose the possibility that phosphorylation might modulate PrP biological activity.

Animals↗
PubMed2000

Antimicrobial activity of crude extracts and pure compounds of Hypericum hircinum.

The antimicrobial activity of the n-hexane (H) and chloroform (C) extracts, the methanol extract (M) and its ethyl acetate (E) and n-butanol (B) fractions, and six isolated constituents of the aerial parts of Hypericum hircinum was investigated using an agar diffusion method. The maximum activity was exhibited by the methanolic extract against Staphylococcus aureus, while all pure constituents showed no antimicrobial activity against the tested microorganisms.

Anti-Bacterial Agents↗
PubMed2000

Effect of subclinical hypothyroidism on body fluid compartments.

OBJECTIVE: The present study was aimed to assess the effects of subclinical hypothyroidism on body composition (BC). SUBJECTS: Thirty-one women (age: 37 +/- 9.9 years) with a wide range of body mass index (BMI) were studied. Subclinical hypothyroidism was defined by a basal TSH > or = 4 mU/L and/or TRH stimulated peak > or = 30 mU/L. MEASUREMENTS: For each subject, weight, height, BMI, multifrequency bioelectrical impedance spectroscopy (BIS) and D2O and NaBr dilution tests were performed to assessed total body water (TBW) and extracellular water (ECW). Thyroid function (basal and TRH stimulated TSH, free T3, and free T4) were determined from fasting blood samples for all subjects. Total body dual energy X-ray absorptiometry (DXA) were used to measure fat mass (FM) and lean mass (Lean). RESULTS: The results of BIS were compared with the TBW and ECW estimated by the dilution techniques on the same individuals. The correlation was R2 = 0.65 for impedance at 5 kHz and ECW by NaBr and R2 = 0.72 for impedance at 100 kHz and TBW by D2O. Intracellular water (ICW) was calculated as differences between TBW and ECW measured by dilution methods. Percent of ECW and ICW were related to BMI (ANOVA, p < 0.001). No difference in TBW, body water distribution and body composition related to thyroid function was demonstrated. CONCLUSIONS: In our patients affected with subclinical hypothyroidism, with or without obesity, only obesity appeared related to TBW, ECW and ICW; the subclinical hypothyroidism, on the contrary, had no effect on compartments of body fluids. Bioimpedance is a valid tool to assess body fluid distribution in subclinical hypothyroidism.

Absorptiometry, Photon↗