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Biomedical subjects

G Forte

Publications and source records attributed to G Forte.

At least 19 recordsLinked to original sources

High-throughput microwave-digestion procedures to monitor neurotoxic elements in body fluids by means of inductively coupled plasma mass spectrometry.

Microwave (MW) digestion procedures with high sample throughput (simultaneous digestion of 36 or 80 samples) and procedural simplicity (disposable plastic tubes, or re-usable liners with screw-cap) were investigated for their efficiency in routine analyses of biological samples. Different digestion vessel materials were tested for metal leaching/adsorption and thermal resistance: quartz, glass, polyethylene (PE) and polystyrene (PS). For the instrumental quantification of Al, Bi, Cd, Co, Cr, Hg, Mn, Mo, Ni, Pb, Sb, and Tl at ultra-trace levels in urine, serum, and whole blood, sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) was used. The different pretreatment conditions and vessels were evaluated in terms of contamination risk, effective power of detection, accuracy, and precision. Results of analyses of serum, urine and whole blood certified reference materials (CRMs) were fully satisfactory for almost all the analytes. In the case of Hg, Mo, and Tl in serum digested in plastic containers the results were just below the lower limit of uncertainty of the certified range. On the basis of the present data the following MW procedures can be suggested: 1. for urine, digestion with nitric acid at atmospheric pressure in plastic vials; 2. for serum, digestion with nitric acid at atmospheric pressure in glass vessels; and 3. for whole blood, digestion under pressure in quartz tubes. Because of the levels of the procedural blanks, Bi was not measurable at the concentrations expected in human fluids, and Al was accurately detectable in whole blood only.

Humans↗

["White-coat hypertension": variation of normality or of hypertension?].

INTRODUCTION: Previous studies have demonstrated a high prevalence of "white coat" hypertension (20%), but it is still controversial if it implies an increase in cardiovascular risk. PATIENTS: Between 1992 and 95 we prospectively studied 175 untreated hypertensive patients aged over 18 years (V Joint National Committee's stage I-II), and 91 controls. DESIGN AND METHODS: The subjects were submitted to clinical evaluation, ambulatory blood pressure monitoring, 24-hour Holter monitoring, signal-averaged ECG, echocardiography/Doppler and ergometry. "White coat" hypertension was defined as mean daytime (6.00-22.00 H) ambulatory blood pressure < 136/87 mm Hg (males) and < 131/86 mm Hg (females). RESULTS: "White coat" hypertension was present in 29 patients (18%). "White coat" hypertension patients had an identical prevalence of smoking, family history of cardiovascular disease, abnormal ECG and retinopathy (> Keith-Wagener II) as patients with daytime hypertension. Ambulatory blood pressure values (24 hour, 6.00-22.00 h, 22.00-6.00 h, sleep, blood pressure load, heart rate) were all significantly different from controls (p < 0.03 to 0.0007). In patients with daytime hypertension, only 24 hour and daytime diastolic ambulatory blood pressure (p < 0.005) were different from "white coat" hypertension patients. Exercise testing blood pressure values (6 min exercise, maximal, 3 min recovery) were significantly different between "white coat" hypertension patients and the control group (n = 70) (p varying from 0.05 to 0.005) but not between "white coat" hypertension and daytime hypertension (n = 33) patients. Diastolic function was studied only in 39 daytime hypertension patients, 10 individuals with "white coat" hypertension and 34 controls (for technical reasons and because we only analyzed individuals younger than 55 years). E velocity and E/A ratio were similar in "white coat" hypertension and daytime hypertension, but only in daytime hypertension patients they reached a significant difference from controls (p = 0.04; p = 0.01), probably due to the small number of patients. CONCLUSIONS: These data (clinical, ambulatory blood pressure, ergometric, diastolic function) suggest that "white coat" hypertension might not be a benign entity.

Blood Pressure↗

Stability of Mercury Dilute Aqueous Solutions: An Open Issue

In the framework of the activities of the European Commission Reference Laboratory (CRL) for residues at the Istituto Superiore di Sanita a number of analytical quality control trials on determination of trace analytes are being carried out. As regards trace elements it soon became apparent that the stability of Hg dilute aqueous solutions is rather unsatisfactory. An investigation was thus undertaken to ascertain the conditions under which the concentration of this metal does not appreciably change. Mercury solutions were prepared in high purity deionized water in the concentration range 1-10 ng g-1 and the effect of various amounts of HNO3 and K2Cr2O7 (alone or in combination) was elucidated by measuring the variations with time in the actual concentration of Hg. Determinations were performed by both inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Results show that solutions added with 5% (w/w) HNO3 and 0.01% (w/w) K2Cr2O7 do not undergo any significant alteration in the nominal content of the analyte for at least 1 month. Similar conclusions are reached in the case of solutions enriched in CaCO3, NaCl, NaNO3, KH2PO4, KNO3, and Mg(NO3)2.6H2O to mimic acid digests of meat samples. The improvement ensuing from the adoption of this approach on the performance of the Hg analytical quality control trials is discussed in detail.

Journal Article↗

Monoethylglycinexylidide production as a measure in predicting hepatic histology.

To clarify whether monoethylglycinexylidide (MEGX) production can be useful in predicting the severity of chronic liver disease, 51 subjects were enrolled in this study: 13 mild-moderate CAH (group A), 9 severe CAH (group B), 29 cirrhosis, 18 compensated and 11 decompensated disease (group C). The patients were injected with a 1 mg/Kg lidocaine bolus i.v. and serum-sampled for MEGX values (time 15, 30 and 60 minutes), determined by TDX-immunoassay. MEGX formation was significantly different (Mann-Whitney U test) in the three groups at each time interval, especially at 30 min: group A = 70.5 +/- 9.9 ng/ml (mean +/- SD); group B = 49.7 +/- 7.2; group C = 37.2 +/- 19.5 (in A vs B, p = 0.0003; in A vs C, p < 0.0001; in B vs C, p = 0.0237). The difference between compensated and decompensated cirrhosis was always significant (p = 0.0099, 0.0005, 0.0113 respectively) but between severe CAH and compensated cirrhosis it was marginal only at 15min (p = 0.0763) and absent at 30 and 60min. At 30min MEGX values > 60 suggest mild-moderate CAH, < 40 cirrhosis, < 30 decompensated cirrhosis, between 40 and 60 severe CAH or compensated cirrhosis. We are of the opinion that the MEGX test could be utilized to predict hepatic histology.

Adult↗

Humanitarian assistance: technical assessment and public health support for coordinated relief in the former Yugoslavia.

Since July 1992, the WHO Regional Office for Europe has been using epidemiological and public health assessment techniques to guide its interventions in the crisis in the former Yugoslavia. WHO field operations have evolved into the largest emergency relief operation ever undertaken in the European Region. The WHO programme of humanitarian assistance focuses on five major areas: public health, equipment, supplies and logistic support, support to war victims, primary health care for refugees and rehabilitation of the health care system. The main thrust of the programme is to implement the public health measures required for survival. The first step is to provide health intelligence for international humanitarian assistance programmes through health and nutrition monitoring. This leads to targeted intervention. While involved in all aspects of relief, WHO clearly justifies its presence by its technical focus, bringing its network of expertise and experience to bear on the assessment of need and the coordination of intervention. Three examples of this approach are given: the nutrition programme, which includes emergency food aid and health and nutrition monitoring, the winter protection programme in Bosnia and Herzegovina, and the medical kit programme, involving the design and use of special kits to cover basic emergency needs for medical supplies to the maximum number of people. In the former Yugoslavia, the WHO Regional Office for Europe has concentrated on technical situation analysis and sound public health grounding to guide and direct intervention.

Humans↗

Immunochemical determination of porcine pancreatic colipase: differentiation between procolipase and its trypsin-activated form.

A noncompetitive enzyme-linked immunosorbent assay (ELISA) has been developed for the quantitative determination of porcine pancreatic colipase. Calibration curves were established by coating polystyrene immunoplates with pure procolipase or its trypsin-activated derivative. Bound antigen was detected with antiporcine procolipase polyclonal antibodies. Under optimizing conditions, the minimal detectable amount of porcine colipase was 0.1 ng, which is about 1,000 times less than the minimal amount that can be assayed titrimetrically. The useful range of the immunoassay was between 0.1 to 1 ng (2-20 micrograms/L). Under standard assay conditions, no distinction can be made between the precursor and activated forms of the cofactor. Results of immunochemical determinations of colipase in porcine pancreatic juice and tissue extract were in good agreement with those obtained with the potentiometric method. The specific determination of activated colipase in pancreatic juice was performed by coating the immunoplates with antigen in solution in PBS with 0.5 g/L of Tween 20. The detergent selectively impaired the binding of procolipase to the plate. Determination of colipase in human pancreatic juice carried out under the same experimental conditions showed that the minimal amount of human cofactor detectable with ELISA was 1 ng due to partial immunological crossreactivity of the human and porcine proteins. Immunoassay performed with antiporcine procolipase monoclonal antibodies (Mab) showed lower sensitivity than that performed with polyclonal antibodies. However, Mab 72.11, a monoclonal antibody that reacted only with porcine procolipase, allowed specific detection and differential determination of the precursor form of porcine colipase in pancreatic juice. ELISA performed with pure human colipase indicated that no antiporcine procolipase monoclonal antibodies cross-reacted with the human cofactor.

Animals↗

[Cardiac arrhythmias in hypertensive subjects with and without left ventricular hypertrophy compared to the circadian profile of the blood pressure].

To evaluate possible correlations between cardiac arrhythmias and circadian pattern of blood pressure (BP) and of heart rate (HR), we studied 2 groups of 20 males with stable arterial hypertension of mild to moderate entity, with (Group I) or without (Group II) left ventricular hypertrophy (LVH). In patients with LVH the mean age (56 vs 46 years), the duration of the hypertensive state (48.1 vs 15.7 months), the thickening of interventricular septum (IVS; 13.7 vs 9.6 mm) and of the posterior wall of the left ventricle (13.2 vs 9.2 mm) and the mass of LV (149.8 vs 99.7 g/m2) were significantly greater (p less than 0.01). On the contrary, the 2 groups did not show significant differences concerning casual BP determined in the morning (178.3/108.4 vs 171.5/106.2 mmHg). After a pharmacological washout of 2 weeks, patients underwent a noninvasive, intermittent, monitoring of BP (every 15 min during daytime and every 30 min from 11 pm to 7 am), using a pressure meter II Del Mar Avionics, and a continuous monitoring of ECG for 24 hours, employing an instrument 445/B Del Mar Avionics. Mean 24-hour BP was not different in the 2 groups of patients (161.7/99.0 vs 158.2/98.3 mmHg); however, patients with LVH showed a significantly greater variability of BP in the morning (7 am-3 pm), while mean 24-hour HR was significantly less (71.6 vs 78.2 b/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The effect of a community hypertension control program.

A hypertension detection and control program sponsored by the Pan-American Health Organization and the World Health Organization (PAHO/WHO) was carried out in an urban health district of Havana City, Cuba. A baseline (initial) survey was conducted on a random sample of the population (greater than or equal to 15 years of age) to assess the problem of hypertension in that community. Subsequently, we extended the program in the same area by taking the blood pressure of as many people as we could, and a health education program on hypertension was developed and implemented. All hypertensive persons were treated. We surveyed about 90% of the adult population (29,640) over a 5-year period. We then conducted a final survey on a second random sample of the population to assess the effect of the program. The response rate to the letter of invitation to visit the hypertension clinic was 50%; 30% of the recall appointments were missed, and the dropout rate was 18.6%. Seventy percent of the hypertensive persons had Stage I disease (PAHO/WHO) with normal electrocardiograms. Before the program, 15.7% of the total number of hypertensive persons surveyed in the area had the disease under good control, and this increased to 31% after the program. Mortality due to cerebrovascular disease was reduced from 11/10,000/yr to 7/10,000/yr, whereas mortality caused by myocardial infarction did not change.

Adult↗

Changes of angiotensin converting enzyme (ACE) levels during activation of the renin-angiotensin-aldosterone system (RAAs).

The aim of this study was to evaluate the changes of ACE levels during RAAs activation induced by: 1) a continuous graded bicycle ergometer test performed in a group of 15 males health youths aged between 21 and 30 years, with average age of 25.8 +/- 2.85 years; 2) i.m. injection of 20 mg of frusemide in 11 health youths (10 males and 1 female), aged between 20 and 30 years, with average age of 24.09 +/- 2.77 years; 3) dialytic treatment in 25 patients (12 males and 13 females), suffering from chronic renal failure, aged between 26 and 68 years, with average age of 54 +/- 15.42 years. Plasmatic renin activity (PRA), aldosterone (ALD) and ACE levels were determined by RIA in basal conditions and at peak of exercise in group 1, 15 minutes after i.m. injection of frusemide in group 2 and after a session of dialysis in group 3. In all the experimental conditions studied there was an activation of the renin-angiotensin system with significant increase of the PRA, ALD and ACE levels.

Adult↗

Prophylactic sclerotherapy of high-risk esophageal varices: results of a multicentric prospective controlled trial.

In this prospective, multicenter trial, 140 cirrhotic patients with no previous upper gastrointestinal bleeding and with esophageal varices endoscopically judged to be at high risk of hemorrhage were randomized to receive either sclerotherapy or conservative treatment for the prevention of first variceal bleeding. The end-points of the study were bleeding and death. Life table curves showed that prophylactic sclerotherapy significantly diminished the incidence of variceal hemorrhage (p less than 0.001) and overall mortality (p less than 0.01). Two-year cumulative bleeding rate was 18% in the sclerosis group (95% confidence interval = 10 and 31) and 57% (95% confidence interval = 40 and 72) in the control group. Two-year cumulative mortality rate was 30% (95% confidence interval = 19 and 45) in the sclerotherapy group and 56% (95% confidence interval = 39 and 72) in the controls. One patient died after hemorrhage from an ulcer secondary to sclerotherapy. Analysis by the Cox model of the factors potentially confounding or interacting with the effect of sclerotherapy suggested that sclerotherapy was more efficient in preventing first bleeding in patients with decompensated disease (Child B and C) than in those in good condition (Child A). However, the 2-year cumulative bleeding rate of untreated Child A patients was only 19%, showing how in this group the endoscopic findings were unreliable in selecting high-risk varices and explaining why after a 2-year follow-up prophylactic sclerosis did not show any benefit in such patients. We conclude that sclerotherapy can decrease the incidence of first variceal bleeding and death for a period of 2 years in cirrhotic patients with high-risk varices.

Adult↗

Patient compliance and medical audit in orthodontics.

For Giancarla Forte and Andrew Richardson ignorance certainly isn't bliss. They decided to find out just how sharp the teeth of their maloccluded cubs were, by posing them the BDA-Colgate questionnaire, 'We care about what you think'.

Appointments and Schedules↗

Pancreatic oncocytic endocrine tumors. Cytologic features of two cases.

BACKGROUND: Oncocytoma designates a usually benign tumor consisting of oncocytes (cells rich in mitochondria). Rarely do endocrine pancreatic tumors show oncocytic transformation, and consequently their liver metastases may resemble a hepatocellular carcinoma. CASES: Case 1, a 36-year-old male, presented with an 8-cm pancreatic mass with multiple liver metastases. Fine needle aspiration (FNA) biopsy was performed on the liver. The cytologic features were highly cellular material; numerous isolated cells and irregular, loose cellular aggregates; rare mitoses; round or polygonal cell shape; rosette formation; and large, granular, eosinophilic cytoplasm (suggestive of poorly differentiated hepatocellular carcinoma). Case 2, a 57-year-old female with hypoglycemia, had a 13-cm pancreatic mass. FNA material showed the same cytologic features as case 1. In situ hybridization to detect albumin mRNA was negative in both cases, while immunocytologic reactions for glandular epithelial cytokeratin and chromogranin A were positive. Case 2 was also positive for insulin. CONCLUSION: Oncocytic transformation in endocrine tumors of the pancreas is a rare occurrence and must be kept in mind in the diagnostic workup of FNA material from tumors of the hepatopancreatic region.

Adenoma↗

Sentinel node mapping for malignant melanoma.

Sixty-seven patients with malignant melanomas were seen in our institute since 1998. We looked for a sentinel node in 26 (38%) patients with lesions thicker than 1 mm, employing a double technique: staining with methylene blue and gamma probe mapping after injection of 99mTc. Forty-six nodes were retrieved, 25% of them containing tumor cells. This approach enabled us to choose between a wait-and-see policy and radical surgery.

Adult↗

Honey as a candidate reference material for trace elements.

The feasibility of producing and certifying new certified reference materials (CRMs) for trace elements in honey was investigated. Preliminary steps for preparation of candidate materials are performed at the Institute for Reference Materials and Measurements, Joint Research Centre of the European Commission (EC-JRC-IRMM). Two different types of honey, Acacia and Eucalyptus, were tested for determination of 10 trace elements. To each type of honey was added a given amount of high purity deionized water to obtain aqueous solutions with an acceptable degree of homogeneity which would require only minimal manipulation before analysis. Average values obtained for the trace elements by means of inductively coupled plasma-based techniques were as follows (in microg/ kg +/- SD): Acacia honey, As, 1.10+/-0.20; Cd, 0.328+/-0.035; Cr, 1.90+/-0.22; Cu, 67.0+/-5; Fe, 215+/-30; Hg, < 0.75; Mn, 82.1+/-6.2; Ni, 21.0 3.0; Pb, 2.30+/-0.25; Se, 9.10+/-1.2; Zn, 167+/-22; Eucalyptus honey, As, 5.99+/-0.10; Cd, 0.592+/-0.074; Cr, 1.50+/-0.07; Cu, 219 24; Fe, 1008+/-114; Hg, <0.75; Mn, 1009+/-51; Ni, 11.3+/-1.5; Pb, 5.00+/-0.40; Se, 5.60+/-0.91; Zn, 791+/-91. When these 2 pilot materials are ready, the certification project will be launched in full compliance with current rules set by EC-JRC-IRMM. If the project is successful, the new CRMs will be put primarily at the disposal of the National Reference Laboratories for trace elements.

Food Analysis↗