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Biomedical subjects

L Ambrosone

Publications and source records attributed to L Ambrosone.

At least 19 recordsLinked to original sources
PubMed2001

Elevated bioactive prolactin levels in systemic lupus erythematosus--association with disease activity.

OBJECTIVE: To assess the possibility that prolactin (PRL) is involved in the pathogenesis of systemic lupus erythematosus (SLE). METHODS: We determined serum PRL levels in 122 serum samples from 78 unselected patients with SLE (73 women, 5 men, age range 16-71 yrs). Disease activity was defined according to Lupus Activity Criteria Count (LACC) and scored by Systemic Lupus Disease Activity Index (SLEDAI). Serum PRL concentrations were determined by immunoradiometric assay (IRMA) and by biological assay (BA) that evaluates Nb2 lymphoma cell proliferation. RESULTS: Hyperprolactinemia (> 20 ng/ml) was found in 21 patients (26.9%) by IRMA and in 31 (39.7%) by BA. A significant correlation between IRMA and BA PRL levels was found (rs 0.46, p < 0.001). According to LACC, SLE was active in 29 patients and inactive in 49. In those with active disease median PRL levels were higher both by IRMA (18.5 ng/ml, range 2.2-51.2 vs 10.6 ng/ml, range 3.9-29.6; p < 0.001) and BA (21.0 ng/ml, range 12.4-84 vs 14.9 ng/ml, range 4.2-46.1; p < 0.001). Hyperprolactinemia was associated with active disease in 13/21 patients (61.9%) by IRMA and in 18/31 (58.1%) by BA (p < 0.01). SLEDAI scores correlated with PRL levels both by IRMA (rs 0.5, p < 0.001) and BA (rs 0.41, p < 0.02). A followup analysis on serum samples from 44 patients seen again after 6-8 mo confirmed the above results. There was no difference in the rate of different clinical manifestations in hyperprolactinemic and normoprolactinemic subjects, apart from the increased prevalence of malar rash and central nervous system manifestations in the patients with hyperprolactinemia (p < 0.03 and p < 0.01, respectively). CONCLUSION: Hyperprolactinemia was frequently detected in patients with SLE by IRMA and by BA and was associated with disease activity. Our findings suggest that PRL may play a role in the pathogenesis of SLE.

Adolescent↗
PubMed2000

Electrochemical methods of evaluating the van't Hoff enthalpy in reactions involving biological macromolecules.

We highlight conditions under which coincidence of van't Hoff and calorimetric enthalpies can be experimentally verified for reactions of biochemical interest. First, we clarify that, often, chemical equations in condensed phase do not explicitly contain information on all processes involved. Second, we underline that the accuracy of electrochemical methods is much higher than that of other non-calorimetric techniques. Electrochemical data on the binding of ethidium ion to DNA are re-examined to verify that the entropy evaluated as the temperature derivative of the free energy agrees in full with the calorimetric one. Third, we point out that unfolding or self-association enthalpies of redox proteins can be reliably obtained by electromotive force measurements, taking advantage of their linkage to redox enthalpies. Thermodynamic cycles coupling biochemical transformations to redox systems are briefly discussed.

Biochemical Phenomena↗
PubMed2000

Cognitive impairment in systemic lupus erythematosus: a follow-up study.

We evaluated outcome and the clinical value of cognitive impairment in systemic lupus erythematosus (SLE). Fifty-one consecutive SLE subjects with or without overt nervous system involvement received two comprehensive neuropsychiatric and neuropsychological assessments, including the Mental Deterioration Battery, the Mini Mental State Examination (MMSE), and tests from the Wechsler Adult Intelligence Scale. The two neuropsychological assessments were made when subjects were in stable neurological condition. Twenty-seven patients were found to have neuropsychiatric symptoms (NP-SLE) at the first assessment, and three others developed them during the follow-up. Fifteen patients (10 NP-SLE) had cognitive impairment at the first assessment. At retest the cognitive deficit persisted in all patients but one (non-NP-SLE) and had developed in four others. In the cognitively impaired subjects scores on MMSE approached the cutoff for an overt dementing condition. No progressively decreasing scores were found on any of the tests. No relationships were shown between neuropsychological diagnosis and neuropsychiatric disorder, neuroradiological findings, disease activity, or steroid and nonsteroid immunosuppressive therapy. Cognitive impairment thus seems to be a stable symptom of CNS involvement in SLE. It corresponds to the subjective complaint of intellectual difficulties and marginal performance on the MMSE. Intellectual deterioration may occur in patients without other symptoms of NP-SLE. Standardized neuropsychological testing methods should be used routinely to assess SLE patients.

Adult↗
PubMed2000

Increased serum concentrations of soluble HLA-class I antigens in hepatitis C virus related mixed cryoglobulinaemia.

OBJECTIVE: To investigate whether quantitative alterations of both beta(2)microglobulin (beta(2)micro) associated HLA class I heavy chains (sHLA-I) and beta(2) micro free class I heavy chains (sHLA-FHC) in sera of patients with hepatitis C virus (HCV) infection occur and whether they distinguish patients with mixed cryoglobulinaemia (MC). METHODS: 83 HCV infected patients were studied and divided into three groups: (A) without cryoglobulinaemia (n=21), (B) with polyclonal MC (n=20), (C) with monoclonal MC (n=42). Serum sHLA-I and sHLA-FHC were measured by double determinant radioimmunoassay using monoclonal antibodies: TP25.99 as catching antibody, and NAMB-1 and HC-10 as revealing antibodies. Western blot identified HLA-I isoforms. RESULTS: The serum concentrations of sHLA-I and of sHLA-FHC in HCV infected patients versus controls were respectively 1.3(0.5) microg/ml (mean (SD)) versus 0.8 (0.3) (p<0. 001) and 13.9 (7.1) ng/ml versus 9.2 (5) (p<0.001). sHLA-I were 1.01 (0.4) microg/ml in group A, 1.04 (0.4) microg/ml in group B, and 1. 47 (0.4) microg/ml in group C (p=0.001). Statistical analysis showed a significant difference versus controls for groups B (p<0.02) and C (p<0.001). sHLA-FHC were 12.8 (8.3) ng/ml in group A, 17.2 (7.1) ng/ml in group B, and 12.9 (6.2) ng/ml in group C (p<0.02). A significant difference versus controls for each group was found (p<0. 02, p<0.001, and p<0.02, respectively). Different patterns of sHLA-I isoforms were observed. CONCLUSIONS: Increased serum concentrations of sHLA-I and sHLA-FHC characterise HCV infected patients. The highest sHLA-I concentrations seem to distinguish patients with monoclonal MC. In this last condition sHLA could play a part in the HCV escape and in B cell proliferation. The significance of sHLA-FHC is still undefined.

Adult↗
PubMed1998

The Interaction of Micelles with Added Species and Its Similarity to the Denaturant Binding Model of Proteins.

The effect of additives on micellar aggregation is treated using the same framework developed for macromolecular binding. This procedure, hinging on the pseudo-phase transition model, allows us to evaluate the binding constant of any added substance to a micellar aggregate as well as the number of particles bound per amphiphilic unit. The analysis of published literature data confirms that the model provides a general description of micellar aggregation in the presence of added ingredients, regardless of their ionic or non-ionic nature. Original data from our laboratory are well described by the suggested macromolecular binding approach. The dependence of experimental trends on micellization modifiers is also briefly discussed. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Infective endocarditis presenting as polyarthritis.

We report the case of a patient who complained of arthralgias and arthritis 1 month before the onset of fever or other signs of infective endocarditis. In 2 months she developed an additive, asymmetrical polyarthritis with fever (febrile polyarthritis). Splenomegaly was present. Two-dimensional echocardiography showed no vegetations or other findings suggesting endocardial involvement. Initially, four blood cultures showed no microorganisms, then six of nine subsequent blood cultures grew highly gentamicin-resistant Enterococcus faecalis.

Adult↗
PubMed1998

Increased level of serum HLA class I antigens in patients with systemic lupus in patients with systemic lupus erythematosus. Correlation with disease activity.

The level of soluble beta2-mu-associated HLA Class I heavy chains (sHLA-I) and of soluble beta2-mu-free HLA Class I heavy chains (sHLA-FHC) was found to be significantly higher in sera from 58 patients with systemic lupus erythematosus (SLE) than in those from 82 age and sex-matched controls. The level of serum sHLA-I in patients with SLE was significantly correlated to disease activity. Western blotting analysis showed that the 44-kDa isoform represents the major component in the antigens immunoprecipitated by anti-beta2-mu mAb NAMB-1 and by anti-beta2-mu-free HLA Class I heavy chain mAb HC-10 from sera of patients with SLE. These results suggest that the increased serum levels of sHLA-I and of sHLA-FHC in patients with SLE reflect their increased shedding from cell membrane. In view of the ability of sHLA-I and of sHLA-FHC to induce apoptosis of activated T cells, it is suggested that their increased serum levels in patients with SLE is triggered by dysregulation of the immune system leading to T-cell activation. The increased serum levels of sHLA-I and of sHLA-FHC may be used by the immune system to control the pool of activated T cells by inducing apoptosis. If this possibility is proven to be correct, modulation of the serum level of sHLA-I and of sHLA-FHC may be utilized to develop strategies to treat SLE.

Adolescent↗
PubMed1998

An unusual case of primary systemic amyloidosis.

Here we report an unusual case of primary systemic amyloidosis. The cutaneous lesions were polymorphic and included involvement of both external auditory canals. The visceral involvement was covert. Mapping of amyloid deposits was performed using scintigraphy with technetium-99m (V) dimercaptosuccinic acid ([99mTc (V)] DMSA). Therapy with melphalan, prednisone and colchicine resulted in considerable improvement.

Aged↗
PubMed1997

Thermodynamic and Dynamic Properties of Micellar Aggregates of Nonionic Surfactants with Short Hydrophobic Tails

The densities and viscosities of binary aqueous mixtures of poly(ethylenoxide)hexanols [C6 H13 (OCH2 CH2 )m OH, C6 Em ] (m = 3, 4, and 5) have been studied in the micellar composition range. For the same surfactants the self-diffusion coefficients in mixtures with heavy water have been determined by the spin-echo pulsed field gradient method. The volumetric data are interpreted by means of the phase separation model, and values of the CMC, volume change, and standard free energy change of micellization are obtained. From the viscosity data the hydration numbers of the surfactant hydrophilic head in the micellar state are computed; they are in agreement with those obtained from HDO self-diffusion data. The surfactant self-diffusion data are used to calculate the apparent micelle radius and the aggregation number. The micellization parameters obtained for the different surfactants are compared and discussed.

Journal Article↗
PubMed1996

Immunoscintigraphy as an adjunct to diagnostic imaging in septic sacroiliitis. Report of a case.

Septic sacroiliitis in childhood is a relatively rare condition. We describe a case of septic sacroiliitis occurring in an 11-year-old girl in whom the diagnosis was suspected on clinical findings and bone scan. Immunoscintigraphy with 99mTc-labelled antigranulocyte antibodies further supported the hypothesis for a septic origin of the disease. The clinical evolution clinched the diagnosis.

Anti-Bacterial Agents↗
PubMed1996

Prevalence of alcohol problems in general practice: an experience from southern Italy.

The Michigan Alcoholism Screening Test (MAST) and the response to a question about heavy alcohol consumption were used to assess the prevalence of alcohol problems in consecutive patients (77 males and 46 females) consulting a general practitioner in an urban area in the South of Italy (Castellammare di Stabia). Alcohol problems, which were defined by a cut-off score of 5 on the MAST and/or by heavy alcohol consumption (corresponding to at least 60 g of ethanol daily for males and 36 g of ethanol daily for females for at least 2 years), were identified in 54 patients [43.9%; 95% confidence interval (CI) 35.0-53.1%], 45 males (58.4%; 95% CI 46.6-69.6%) and nine females (19.6%; 95% CI 9.4-33.9%). The prevalence of MAST positive patients was 32.5% (95% CI 24.4-41.6%) in the total patient sample, 45.5% (95% CI 34.1-57.2%) among males and 10.9% (95% CI 3.6-23.6%) among females. The question about heavy alcohol consumption had a predictive negative value of 97.2% (95% CI 90.2-99.7%) and a predictive positive value of 73.1% (95% CI 59.0-84.4%) in relation to MAST positive patients. It is suggested that general practitioners should incorporate this question about heavy alcohol consumption as a screening question in order to detect alcohol problems and give advice regarding reduction of alcohol consumption.

Adolescent↗
PubMed1994

Avascular osteonecrosis in patients with SLE: relation to corticosteroid therapy and anticardiolipin antibodies.

Sixty-nine unselected SLE patients were studied to evaluate the prevalence of avascular osteonecrosis (AVN) and its relationship with steroid therapy and with anticardiolipin antibodies (aCL). All the patients were under treatment with corticosteroids. AVN occurred in seven occurred in seven of the 69 patients (10.14%) and was not related to corticosteroid intake. Seventeen of the 69 patients were also treated with methylprednisolone pulse therapy (MPPT) and cumulated the highest corticosteroid doses but none of them suffered from AVN. Excluding the 17 MPPT-treated SLE patients, corticosteroid intake was significantly higher in the AVN-SLE patients. Abnormal IgG and/or IgM aCL serum levels were found in two of the seven AVN-SLE patients and in 24 of the 62 non-AVN SLE, without a statistically significant difference. None of the seven AVN-SLE patients showed features of antiphospholipid syndrome. We conclude that in SLE patients a continuous high-dose steroid treatment may be considered a risk factor for AVN. On the contrary, MPPT regimen may reduce this risk. Anticardiolipin antibodies might represent an added factor which could play a role in some patients but not in all.

Adolescent↗
PubMed1991

A case of portal thrombosis arisen after treatment with dihydroergotamine.

We describe the case of a 42 year old woman with abdominal pain, ascites, and splenomegaly after having taken dihydroergotamine continuously for three months due to frequent hemicranic episodes. The celiac-mesenteric angiography demonstrated diffuse thrombosis of splenic, superior mesenteric and portal veins. No surgical intervention was possible. We believe that it is possible that dihydroerogotamine, a hydrogenated derivative of ergotamine, inasmuch as it is capable of causing peripheral vasoconstriction, intimal lesions, arterial and venous thrombi, was also the cause of our patient's portal thrombosis. We therefore suggest the minimum effective amount of the drug be utilized to achieve the relief of cephalalgia.

Adult↗
PubMed1989

Detection of microorganisms in clinical specimens using slides prestained with acridine orange (AOS).

Slides prestained with acridine orange (AOS) were used for direct examination of microorganisms in clinical specimens. The method is simpler than a commonly used acridine orange stain (AO) and has the advantage of being a supravital stain. Results indicate that the AOS method is sensitive, and allows rapid detection of microorganisms, even in the specimens containing few microorganisms, e.g. cerebrospinal fluid. Moreover AOS may be the choice method for detection of Trichomonas vaginalis.

Acridine Orange↗