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L Monti

Publications and source records attributed to L Monti.

At least 19 recordsLinked to original sources
PubMed1992

Determination of plasma [6,6-2H2]glucose enrichment by a simple and accurate gas chromatographic-mass spectrometric method.

An improved method for the evaluation of glucose turnover rate in humans, using a prime-continuous infusion of [6,6-2H2]glucose, was developed. Deproteinization of plasma and conversion of glucose into the aldononitrile pentaacetate derivative are the only sample manipulations required prior to the gas chromatographic-mass spectrometric analysis. In six normal adults (prime = 5 mg kg-1; continuous infusion = 0.05 mg kg-1 min-1) the hepatic glucose output calculated at steady state by the procedure described here was 2.1 +/- 0.2 mg kg-1 min-1, the isotopic enrichment being determined with a coefficient of variation of ca. 2%. In six additional subjects, with half of the above-mentioned doses of labelled glucose, the mean hepatic glucose output was exactly the same (3.2% coefficient of variation for the isotopic enrichment measurement). The method described allows the hepatic glucose output to be precisely determined with savings both of time and of labelled glucose.

Blood Glucose↗
PubMed1992

Dose-response characteristics of human proinsulin and insulin in non-insulin-dependent diabetic humans.

We compared the actions of human proinsulin and insulin on glucose turnover and on intermediary carbohydrate and lipid metabolism in non-insulin-dependent diabetes mellitus (NIDDM). Six diet-controlled weight-matched (25.4 +/- 1.0 kg/m2) NIDDM subjects underwent six separate isoglycemic clamps. Glucose turnover was measured using a primed continuous infusion of [6',6'-2H2]glucose. Each subject received three low-dose intravenous infusions of both insulin and proinsulin. Blood glucose was maintained at 6.7 +/- 0.3 mM during proinsulin and insulin infusion. Insulin (I) infusions gave steady-state levels of 0.12 +/- 0.001 (I1), 0.18 +/- 0.01 (I2), and 0.33 +/- 0.01 nM (I3). Steady-state proinsulin (P) levels were 2.5 +/- 0.1 (P1), 4.3 +/- 0.2 (P2), and 8.8 +/- 0.9 nM (P3). Hepatic glucose production was suppressed equally by proinsulin and insulin at all doses. The metabolic clearance rate of glucose was significantly increased during the insulin infusion compared with proinsulin. The use of [6',6'-2H2]glucose resulted in a mean underestimation of the glucose infusion rate of 10.0 +/- 4.0 and 6.0 +/- 2.5% during the two highest insulin and proinsulin doses, respectively. Proinsulin had a significantly weaker effect than insulin, at the lowest infusion dose, in percent suppression of plasma nonesterified fatty acids, blood glycerol, and beta-hydroxybutyrate levels (all P less than 0.05). Blood lactate levels were lower during the P1 (628 +/- 43 microM) and P2 (657 +/- 93 microM) infusions compared with I1 (776 +/- 60 microM) and I2 (878 +/- 44 microM; P less than 0.05, P less than 0.02), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus, Type 2↗
PubMed1992

A comparison of four methods for assessing in vivo beta-cell function in normal, obese and non-insulin-dependent diabetic man.

Several methods of varying complexity are available for the measurement of in vivo insulin secretion in man. No study has previously compared these in the same subjects to establish which is the most appropriate for routine use. We have, therefore, compared four methods for measuring insulin secretion in man: Hyperglycaemic clamp (Hy), Minimal model (MIN), shortened intravenous glucose tolerance test (IVGTT) and continuous infusion of glucose with model assessment (C.I.G.M.A.). Seventeen subjects with varying degrees of insulin sensitivity were studied. Seven normal (BMI 22.5 +/- 1.5 kg/m2), five obese (BMI 38 +/- 5 kg/m2) and five NIDDM subjects (BMI 27 +/- 3 kg/m2) were investigated, in a randomised fashion, on separate days. First (PSI) and second phase (PSII) rate constants (MIN); incremental insulin secretion 0-10 mins (Hy delta I) and steady state insulin levels from the last 30 minutes (Hy120-150) from the hyperglycaemic clamp; 3 minute insulin concentration and incremental area under insulin secretion curve 0-10 min (IVGTT) and beta-cell function (%) from C.I.G.M.A. were used as indicators of insulin secretion. Each index of insulin secretion could detect an overall difference between the groups. Insulin secretion in normals and obese was similar but significantly increased compared to NIDDM. In normals PSI correlated with C.I.G.M.A. (Rs = 0.92, p < 0.02) and Hy120-150 (Rs = 0.82, p < 0.05). IVGTT0-10 correlated with PSII (Rs = 0.83, p < 0.05), HY delta I (Rs = 0.84, p < 0.05) and IVGTT3 min (Rs = 1.0, p < 0.001). In obese PSII correlated with C.I.G.M.A. (Rs = 0.91, p < 0.05), Hy delta I (Rs = 1.0, p < 0.02) Hy120-150 (Rs = 0.92, p < 0.05) and IVGTT3 min Rs = 1.0, p < 0.02). In addition Hy delta I also correlated with C.I.G.M.A. (Rs = 0.92, p < 0.05) and IVGTT3 min (Rs = 1.0, p < 0.02). In NIDDM Hy delta I correlated with C.I.G.M.A. (Rs = 0.91, p < 0.005). When all subjects from the three groups were combined, significant positive correlations were obtained between each index of insulin secretion. In conclusion we have demonstrated that: (a) C.I.G.M.A., IVGTT, Minimal model and hyperglycaemic clamp can provide similar overall results for, in vivo, beta-cell function in man. (b) Significant positive correlations were obtained between each index of insulin secretion when all subjects were combined. (c) Using the above methodologies insulin secretion in normal and obese appears similar but significantly increased compared to NIDDM subjects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

[Significance of the combination of small intestine enema and ultrasonography in the follow-up of Crohn's disease. Clinical correlations].

High-resolution US yields important information for the study of Crohn's disease. A more accurate follow-up is possible by the integration of US with radiological and clinical findings. Sixty-two patients with suspected or known Crohn's disease were examined with double-contrast small bowel enema and high-resolution US. The latter allowed the demonstration of such pathologic findings as mesenteric thickness greater than 15 mm, submucosal thickness (third hyperechoic layer greater than 50% of total bowel wall thickness), lymphadenopathies, and fluid collections. The authors suggest that US grading be performed, and radiological correlations made. The combined use of the two techniques yields better results and allows a better assessment of the patients, which is very useful for both prognosis and therapy.

Adolescent↗
PubMed1991

[Integrated imaging of hepatocarcinoma. Personal experience].

Hepatocellular carcinoma (HCC) is the commonest primary tumor of the liver; of late, its incidence has increased in the Western world. The authors report their experience with 42 patients affected with HCC; 36 cases were confirmed by fine-needle biopsy (FNAB), and 2 by surgery. All patients were studied with US and CT; 25 of them underwent color-Doppler US, and 30 angiography. In 9 patients, Lipiodol-CT was performed after hepatic arterial chemo-embolization. Thirty-six expansive and expansive-infiltrative lesions were observed, 4 infiltrative ones, and 1 neoplastic thrombosis of the portal vein with no evidence of parenchymal mass; 28 cases were multinodular in nature. US showed the primary lesion in all cases, while CT missed 2 lesions of 15 mm in diameter. In 19 of 25 cases studied with color-Doppler US, arterial pathologic signals were observed. Angiography confirmed all the primary lesions diagnosed by US in 30 patients and was found to be the most sensitive method to reveal multinodular lesions 8-15 mm phi, whereas Lipiodol-CT had higher resolution in detecting nodules up to 3 mm phi. The retrospective review of our results pointed out the capabilities of diagnostic imaging techniques in characterizing and staging HCCs--which is the reason why the role of biopsy has not been emphasized. The whole of the morphofunctional data obtained with the different techniques allowed lesion tissue characterization.

Adolescent↗
PubMed1990

Diabetic retinopathy in chronic pancreatitis.

Using fluorescein angiography, we studied the prevalence and characteristics of diabetic retinopathy in 40 patients with chronic pancreatitis complicated by diabetes and in 40 type 1 diabetics with comparable duration of diabetes. Retinopathy was found in 19 pancreatitis patients (47.5%) and in 20 type 1 diabetic patients (50%); it was background, minimal, or mild to moderate, without impairment of visual function, in all 19 pancreatitis patients and in 17 of the 20 type 1 diabetics. In the remaining three idiopathic diabetics, retinopathy was background of severe degree in two and proliferative, with impairment of vision, in one. No differences between patients with and without retinopathy were observed in fasting blood glucose, glycosylated hemoglobin, serum cholesterol, or triglyceride levels. The only significant difference (p less than 0.001) was the greater duration of diabetes in patients with retinopathy when compared with those without it (10.8 +/- 5.7 vs. 5.2 +/- 3.9 yr in pancreatitis patients; 11.2 +/- 5.0 vs. 5.1 +/- 3.5 yr in type 1 diabetics; mean +/- SD). Contrary to what is generally believed, the results indicate that the risk of retinopathy and the characteristics of this complication in patients with chronic pancreatitis and secondary diabetes are similar to those in patients with idiopathic diabetes.

Blood Glucose↗
PubMed1990

[Ultrasonography in the study of synovial disorders and tendon lesions in rheumatoid arthritis].

Conventional radiology is the main diagnostic tool for the visualization of osteoarticular lesions in rheumatoid arthritis. Articular effusions and popliteal cysts were examined with US. This paper is aimed at proving US capabilities in yielding important information about articular and peri-articular soft tissues in the early phases of rheumatoid arthritis. Over the last 30 months, the shoulder, wrist, hand, knee, and hip of 73 rheumatoid patients were studied by means of US and conventional and microfocal radiography. The patients were divided into 2 groups according to the time of onset of the disease. In group A, US demonstrated early synovial exudative inflammation, whereas conventional and microfocal radiography mainly demonstrated soft tissue swelling. In group B (where the first onset dated back to over 1 year), US demonstrated exudative and proliferative changes, together with recurrences. The authors believe US to be able to recognize the early changes of rheumatoid arthritis: as a matter of fact, US shows articular and periarticular soft tissues abnormalities and allows a differential diagnosis to be made between exudative and proliferative forms.

Arthritis, Rheumatoid↗
PubMed1987

Audiologic abnormalities in cases of vitiligo.

The audiologic function in 50 patients affected by vitiligo was studied. Eight patients (16%) had sensorineural hypoacusis when first seen by us. The relationships between melanocytes of the inner ear and auditory function are discussed.

Adolescent↗
PubMed1976

Effect of short- and long-term administrations of some drugs on rat intestinal flora. Short communication.

Two schedules of treatment were adopted for an experimental evaluation of drug induced alterations in mid-small intestinal flora of normal rats. Test substances were given orally twice daily for 3 days at large doses and once daily for 30 days at lower doses. Indometacin, benzydamine, phenylbutazone, pheprazone, picosulfol, magnesium sulfate, tolbutamide, phenformin, dexamethasone acetate and prednisolone acetate were tested. Drug-induced alterations in rat intestinal flora resulted more evidently following multiple short-time treatments.

Administration, Oral↗