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Biomedical subjects

L Guerra

Publications and source records attributed to L Guerra.

At least 181 records · Page 10Linked to original sources
PubMed1986

Ofloxacin: bactericidal effect in an in vitro pharmacokinetic model.

Ofloxacin has been evaluated in an in vitro model where microorganisms were exposed to the varying concentrations met in human serum after the oral administration of a 200 mg dose. The recently isolated strains were selected with minimum inhibitory concentrations (MICs) representative of the MICs 90% of ofloxacin against the species considered. Results showed that ofloxacin sterilized the bacterial cultures of S. aureus, P. morganii and E. coli, with 99.99% of killing still evident for P. aeruginosa after 12 hours of exposure. All the reference compounds (amoxicillin 1 g b.i.d., cefaclor 500 mg t.i.d., rifampicin 450 mg b.i.d.) showed, in the same test, worse results than ofloxacin.

Amoxicillin↗
PubMed1986

Ofloxacin: therapeutic activity in experimental infections.

The therapeutic activity of ofloxacin, a new oral fluoroquinolone antibacterial agent, was tested in experimental infections in rodents. Its activity was compared with that of nalidixic acid, norfloxacin, amoxicillin and cotrimoxazole in Pseudomonas aeruginosa pyelonephritis in the rat, and with that of amikacin and cefotaxime in Proteus morganii thigh infections in mice. Ofloxacin proved to be more effective than reference drugs, even if parenterally administered, in reducing the bacterial count in muscle, kidney and urine.

Administration, Oral↗
PubMed1986

Insulin and C-peptide responses to 75 g oral glucose load in the healthy man.

Plasma insulin and C-peptide levels in the fasting state and after a 2-h 75 g oral glucose tolerance test (OGTT) in a large number of healthy subjects are reported. 247 volunteers (134 males, 113 females), aged 13-69 years, who had a negative history of diabetes, no history of significant disease, normal physical examination, normal body weight, normal glucose tolerance, normal blood tests, and who were taking no drugs were studied. Results, mean +/- SEM (range): fasting glucose concentration = 4.64 +/- 0.03 mmol/l (3.10 - 6.10), 1-h glucose concentration = 5.23 +/- 0.10 mmol/l (2.20 - 9.90), 2-h glucose concentration = 4.11 +/- 0.06 mmol/l (2.00 - 6.80); fasting insulin level = 0.088 +/- 0.002 nmol/l (0.03 - 0.28), 1-h insulin level = 0.45 +/- 0.01 nmol/l (0.06 - 1.63), 2-h insulin level = 0.24 +/- 0.01 nmol/l (0.05 - 1.12); fasting C-peptide concentration = 0.60 +/- 0.01 nmol/l (0.14 - 1.34), 1-h C-peptide concentration = 2.17 +/- 0.05 (0.63 - 8.56), 2-h C-peptide concentration = 1.77 +/- 0.04 nmol/(0.35 - 5.74). Fasting insulin and fasting C-peptide concentrations correlated to post-glucose insulin and C-peptide concentrations, respectively. At each sampling-point insulin concentration correlated to C-peptide concentration. After glucose ingestion, both insulin and C-peptide plasma levels correlated significantly with the corresponding glucose levels. During fasting, C-peptide but no insulin level correlated to glucose level.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Comparative study of scintigraphy, x-ray computed tomography and magnetic resonance imaging in the diagnosis of osteonecrosis of the hip and algodystrophy].

Effectiveness of modern imaging techniques were compared when used for diagnosis of the painful hip in adults, particularly the distinction between aseptic osteonecrosis and decalcifying osteodystrophy. Although a small number of patients were studied (5 cases of osteonecrosis and 5 of decalcification) the series was homogeneous (same investigator for each technique and identical equipment for each patient), and the different methods of investigation (conventional radiology, scintigraphy computed scanography CE 10,000 and 0.15 resistive NMR imaging) could be validly compared. NMR images were recorded in only 5 patients but evaluation involved findings during use of this method of hip investigation over a period of 8 months. Results of comparison of the different imaging methods in osteonecrosis and osteodystrophy of hip showed conventional radiology to be much less effective for diagnosis. Conventional bone scintigraphy appeared to provide a good diagnostic approach, while C.T. images appeared to be as effective or even more specific than scintigraphy for differential diagnosis of the two affections. The only uncertainty is based on the radiologic latency in early stage disease, probably able to be filled by a densitometry. The use of NMR imaging appears to be promising, since it provides data as early as scintigraphy and as specific as scanography, particularly in view of apparent discrimination between osteonecrosis and osteodystrophy of the hip with respect to measurement of relaxation parameters.

Bone Diseases, Developmental↗
PubMed1984

Peripheral hyperinsulinemia of simple obesity: pancreatic hypersecretion or impaired insulin metabolism?

Insulin and C-peptide levels in peripheral blood in the fasting state and after an oral glucose load were measured in 65 nondiabetic, obese subjects and 65 age- and sex-matched nondiabetic normal weight subjects. Fasting insulin and C-peptide levels were significantly higher in obese than in nonobese subjects, whereas 1 and 2 h after the oral glucose load only insulin concentrations were significantly higher in the obese subjects. C-peptide to insulin molar ratios, as well as the relation between the incremental areas of the two peptides, were used as relative measures of hepatic insulin extraction. In the fasting state the ratios between C-peptide and insulin were similar in obese and nonobese subjects, whereas after glucose they were significantly lower in the obese individuals. Similarly, the relations between C-peptide and insulin incremental areas were significantly lower in obese than in nonobese subjects. The comparison of the corresponding plasma levels and areas of C-peptide and insulin after glucose showed that for the same C-peptide value, the insulin value was higher in the obese group. Last, in obese subjects the parameter used as an estimate of hepatic removal of insulin after oral glucose inversely correlated with the fasting insulin concentration and the insulin incremental area after glucose. These results suggest that in obesity peripheral hyperinsulinemia depends on pancreatic hypersecretion of insulin in the fasting state and impaired hepatic insulin metabolism after oral glucose loading.

Adult↗
PubMed1983

Extracapillary glomerulonephritis with necrotizing vasculitis in D-penicillamine-treated rheumatoid arthritis.

Rapidly progressive glomerulonephritis occurred in a woman with rheumatoid arthritis (RA) who had been treated with D-penicillamine for 3 months. Light microscopy study of the kidney showed severe glomerulonephritis with crescent formation in 50% of glomeruli and necrotizing vasculitis. Immunoflurescence revealed IgA and C3 granular deposits diffusely distributed along the capillary walls. The patient was treated with steroid 'pulse', antiplatelet agents and heparin and a partial recovery of renal function was observed after 2 months of anuria. This renal picture is unlike that reported in RA and a causative role for D-penicillamine is suggested.

Arthritis, Rheumatoid↗
PubMed1983

ARDS due to ingestion of denatured rapeseed oil.

Among the different etiologies of noncardiogenic acute pulmonary edema is found the administration or ingestion of various substances. We have studied two patients with ARDS secondary to the ingestion of toxic oil. Both patients presented similar roentgenographic findings characterized by interstitial and alveolar infiltration in "butterfly" distribution, pleural effusion, and a normal cardiac silhouette. The two cases also showed a pulmonary compliance either normal or slightly diminished. With the aid of artificial ventilation, they evolved favorably, gaseous exchange and chest x-ray films returning to normal 16 and 22 days after admission.

Adult↗
PubMed1981

Factor VIII/von Willebrand factor in glomerular nephropathies.

Levels of factor VIII/von Willebrand factor were measured in 105 patients affected by glomerulonephritis either of primary origin or associated with systemic diseases. The median plasma concentration of factor VIII-related antigen was significantly higher in the patients than in healthy controls. Amongst patients with primary glomerulonephritis, higher levels were observed in minimal change nephropathy than in other types. In patients with secondary glomerulonephritis, plasma factor VIII-related antigen was particularly elevated in lupus nephritis and in renal amyloidosis. Altogether, patients with the nephrotic syndrome showed higher levels than patients with lesser degrees of proteinuria. A negative correlation was found between the plasma concentration of factor VIII-related antigen and that of serum albumin but no correlation was observed with the extent of proteinuria. In 48 patients, plasma factor-VIII procoagulant activity was also measured and found to be elevated to the same extent as factor VIII-related antigen in the majority of cases. The urinary excretion of factor VIII-related antigen, evaluated in 72 patients, was found in variable amounts in 31 cases without any correlation with proteinuria. Glomerular deposits of factor VIII-related antigen were an uncommon finding. After 24 months, there was no clear evidence of an unfavourable association between increased plasma levels of factor VIII-related antigen and the course of the disease. Our findings suggest that the measurement of levels of factor VIII/von Willebrand factor in plasma or urine must be interpreted with caution in predicting the clinical course of patients affected by glomerular disease.

Antigens↗
PubMed1981

Renal lesions in essential mixed IgG-IgM cryoglobulinemia. Study of 48 cases.

56 renal biopsies in 48 patients affected by essential mixed IgG-IgM cryoglobulinemia have been examined by light microscopy and immunofluorescence. Patients were classified in four groups: 1) minimal lesions (4 patients); 2) pure proliferative mesangial lesions (9 patients); 3) membranoproliferative glomerulonephritis (23 patients); 4)proliferative glomerulonephritis with prominent intraluminal thrombi (12 patients). In this last group large intraluminal thrombi intensely fixing anti-IgG and IgM antisera were present; unlike the preceding groups, few deposits on capillary walls were seen. These four groups differed in renal clinical syndrome at presentation: in particular, proteinuria or nephrotic syndrome was the predominant manifestation in group 3, acute nephritic syndrome in group 4. In the latter, reversal of renal failure and regression of lesions could be observed. Various morphological aspects tend to show that in this disease more than one mechanism is operating in producing renal damage, including local trapping of abnormal circulating proteins.

Cryoglobulinemia↗
PubMed1977

The prognostic value of some clinical and histological parameters in membranoproliferative glomerulonephritis (MPGN): report of 112 cases.

112 cases of MPGN, whose diagnosis was made on light microscopy, were reviewed. Histological examination showed 66 cases of 'classical' MPGN, 33 of MPGN with a lobular pattern and 13 of MPGN with epithelial crescents. In 11 patients dense intramembranous deposits were observed. On immunofluorescence (95 cases) 62 patients showed deposits of C3 together with immunoglobulins, 20 had a predominant deposition of C3 and in 13 C3 alone was present. At the moment of biopsy 57 patients had nephrotic syndrome, 43 hypertension, 43 impaired renal function and 65 hypocomplementaemia. In 23 cases, one or more episodes of macroscopic haematuria occurred. The actuarial survival was 70% after 10 years and 50% after 20 years from onset. At last observation 25 patients were dead or on haemodialysis, 22 had impaired renal function, 62 had normal renal function and 2 were in complete remission. The histological variety with epithelial crescents had a significantly worse outcome. The presence of dense deposits or of any specific immunofluorescence pattern had no prognostic significance. Nephrotic syndrome, renal function impairment and hypertension indicated a poor prognosis: however, macroscopic hamaturia or hypocomplementaemia did not influence the outcome.

Adolescent↗
PubMed1976

Immunofluorescence patterns in chronic membranoproliferative glomerulonephritis (MPGN).

90 patients, whose renal biopsies showed on light microscopy a pattern of MPGN, have been studied by immunofluorescence. 10 cases showed dense intramembranous deposits. Fluoresceinated antisera against IgG, IgA, IgM, C3, fibrinogen, IgD, IgE, C4, C1q, properdin and C3A were employed. Granular depostis of C3 were observed in all cases; IgG, IgM, properdin, C1q and C4 were found in 2/3 cases; IgA, IgE and C3A were rarely found. The localization of these deposits was parietal and often also mesangial. On the basis of glomerular deposition of C3 with or without immunoglobulins (Ig), we separated the cases into three groups: 1) C3 + Ig (59 cases), 2) predominant C3 (19 cases), 3) isolated C3 (12 cases). Most patients with dense deposits disease were classified in the third group. Deposits of C1q and C4 were found only in the first two groups. The localization of C3 deposits showed a more frequent mesangial extension in the second and third groups. Patients in these 3 groups also had different serum complement profiles. No significant differences in the major clinical features could be found in the 3 groups. Variable immunofluorescence patterns, in agreement with other serological parameters, confirm the heterogeneity of pathogenetic mechanisms in patients with MPGN.

Complement C1↗
PubMed1975

Complement deposition in glomerular diseases.

Biopsies from 400 patients affected by glomerular diseases, both "primary" and secondary to systemic diseases, have been studied by immunofluorescence. Staining was performed for immunoglobulins fibrogen and C1q, C4, C3 and C3A. C1q, C4 and C3 were positive in a high percentage of cases in focal glomerulosclerosis, membranoproliferative glomerulonephritis, lupus nephritis and essential cryoglobulinaemia glomerulonephritis. C1q and C4 were very rarely present in focal proliferative glomerulonephritis and rheumatoid purpura glomerulonephritis. C3A was found frequently only in acute glomerulonephritis. Results are discussed with reference to their diagnostic value and to information about mechanisms of complement activation.

Complement C1↗