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Biomedical subjects

G Lombardi

Publications and source records attributed to G Lombardi.

At least 55 records · Page 3Linked to original sources

Comparative evaluation of Sensititre YeastOne vs. the NCCLS M27A protocol and E-test for antifungal susceptibility testing of yeasts.

A recently developed microdilution method (Sensititre) YeastOne) may represent a valid alternative to the National Committee for Clinical Laboratory Standards (NCCLS) method for routine testing. The Medical Mycology Committee of the Associazione Microbiologi Clinici Italiani (AMCLI) decided to evaluate its reproducibility and reliability compared with the NCCLS M27A protocol and the E-test. Nineteen strains each of Candida albicans and Ca. parapsilosis, isolated from systemic infections, were tested against amphotericin B, flucytosine, ketoconazole, itraconazole, and fluconazole. All the participating laboratories tested the YeastOne panels, while the E-test and the NCCLS method were performed by two laboratories each. Interlaboratory reproducibility showed a good correlation (from 95% for amphotericin B to 92.5% for flucytosine). The agreement between NCCLS and YeastOne ranged from 95 (ketoconazole and itraconazole) to 100% (amphotericin B and flucytosine), whereas the agreement between E-test and YeastOne ranged from 72.5 (fluconazole) to 100% (amphotericin B and flucytosine). The Sensititre YeastOne panels appear to be an excellent alternative to both the E-test and the NCCLS protocol for antifungal susceptibility testing.

Amphotericin B↗

Myocardial contractility and total arterial stiffness in patients with overt hyperthyroidism: acute effects of beta1-adrenergic blockade.

OBJECTIVES: To ascertain whether myocardial contractility and total arterial stiffness are significantly altered in human thyrotoxicosis, and to what extent they are affected by acute beta(1)-adrenergic blockade. METHODS: Doppler-echocardiography was used to assess left ventricular (LV) structure and function, hemodynamics and total arterial stiffness in untreated overt hyperthyroid patients before and 2 h after 5 mg bisoprolol given orally compared with age- and sex-matched healthy euthyroid controls. RESULTS: Compared with controls, untreated patients (n=20) had a higher heart rate (HR) and LV stroke index (SI), which were associated with higher pulse pressure (PP), larger LV end-diastolic volume index (EDVI, an index of preload,+11%, P<0.05), marginally increased stress-corrected LV midwall fractional shortening (MWS, an index of myocardial contractility,+5%; P=0.066), and shorter isovolumic relaxation time (IVRT). These changes resulted in a higher cardiac index (CI) and a lower systemic vascular resistance (SVR), which were associated with fairly normal mean blood pressure (BP) but higher PP/stroke volume (an index of total arterial stiffness,+29%; P<0.01). After bisoprolol, compared with controls, the randomly treated patients (n=10) had comparable HR but additionally increased SI; PP remained enhanced, EDVI was further enlarged (+26%, P<0.001), stress-corrected MWS was substantially unchanged, and IVRT remained shorter. Overall, these effects attenuated the high-output state, which was associated with normalization of PP/stroke volume without changes of mean BP. CONCLUSIONS: In human overt hyperthyroidism, myocardial contractility does not play a major role in increasing LV performance, which is instead predominantly sustained by increased preload with enhanced LV diastolic function. In addition, human thyrotoxicosis is associated with increased total arterial stiffness despite fairly normal mean BP. In this scenario, acute beta(1)-adrenergic blockade blunts the cardiovascular hyperkinesia predominantly by slowing HR - a process that is associated with normalization of total arterial stiffness.

Adrenergic beta-1 Receptor Antagonists↗

The heart: an end-organ of GH action.

Several experimental and clinical studies have indicate that the heart is an end-organ of GH action. Patients with either childhood- or adulthood-onset GH deficiency (GHD) have abnormalities of cardiac structure and function, such as reduced cardiac mass, impaired diastolic filling and reduced left ventricular response at peak exercise. These cardiovascular abnormalities can be reversed, at least partially, after GH replacement therapy. On the other hand, the chronic overproduction of GH and IGF-I in acromegaly leads to the development of a specific cardiomyopathy. Concentric cardiac hypertrophy occurs in more than two-thirds of patients at diagnosis and is commonly associated with diastolic dysfunction. In later stages, impaired systolic function ending in heart failure can occur if GH/IGF-I excess is not controlled. Additionally, acromegalic cardiomyopathy is complicated by abnormalities of cardiac rhythm and cardiac valves. Successful control of acromegaly is accompanied by a decrease of the left ventricular mass and improvement of cardiac function. These beneficial effects appear earlier in young patients with short disease duration than in elderly patients. In conclusion, GH and IGF-I play a main role in the regulation of cardiac development and performance.

Acromegaly↗

Cardiovascular complications in acromegaly.

Cardiovascular morbidity and mortality are increased in acromegaly. In fact, GH and IGF-I excess induces a specific cardiomyopathy. The early stage of acromegaly is characterized by the hyperkinetic syndrome (high heart rate and increased systolic output). Frequently, concentric biventricular hypertrophy and diastolic dysfunction occur in acromegaly, leading to an impaired systolic function ending in heart failure if the disease is untreated or unsuccessfully untreated. Besides, abnormalities of cardiac rhythm and of valves have been also described in acromegaly. The coexistence of other complications, such as arterial hypertension and diabetes, aggravates the acromegalic cardiomyopathy. The suppression of GH/IGF-I following an efficacious therapy could decrease left ventricular mass and improve cardiac function. In conclusion, a careful evaluation of cardiac function, morphology and activity seems to be mandatory in acromegaly.

Acromegaly↗

Shading Vita YZ substructures: influence on value and chroma, part I.

All-ceramic restorations should reproduce as well as possible the color of the natural teeth to create a restoration in accordance with the esthetic wishes and ideas of the patient. The basic color of zirconium oxide is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of the neighboring teeth. In this study, the influence of differently shaded frameworks made of Y-TZP by Vita and 3M ESPE and by Enrico Steger (without, with 0.5 mm, or with 1.0 mm ceramic veneer with Base Dentin) on the brightness, saturation, and color shade (= value, chroma, and hue) was measured and assessed with the aid of a spectral photometer (EasyShade, Vita) in a clinical case in the mouth and on the model. By adaptation to the basic shade, the shading of substructures made of Y-TZP can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color and should be performed in the future as a matter of routine. In this way, more substance can be conserved when restoring the teeth without having to accept an impairment of the esthetic result.

Color↗

Follow-up of differentiated thyroid carcinoma.

Thyroid cancer is the most common endocrine malignancy. More than 90% of primary thyroid cancers are differentiated papillary or follicular types. The treatment of differentiated thyroid carcinoma (DTC) consists of total thyroidectomy and radioactive iodine ablation therapy, followed by L-thyroxine therapy. The extent of initial surgery, the indication for radioiodine ablation therapy and the degree of TSH-suppression are all issues that are still being debated cancers are in relation to the risk of recurrence. Total thyroidectomy reduces the risk of recurrence and facilitates (131)I ablation of thyroid remnants. The aim of radioiodine ablation is to destroy any normal or neoplastic residuals of thyroid tissue. These procedures also improve the sensitivity of thyroglobulin (Tg) as a marker of disease, and increase the sensitivity of (131)I total body scan (TBS) for the detection of persistent or recurrent disease. The aim of TSH-suppressive therapy is to restore euthyroidism and to decrease serum TSH levels, in order to reduce the growth and progression of thyroid cancer. After initial treatment, the objectives of the follow-up of DTC is to maintain adequate thyroxine therapy and to detect persistent or recurrent disease through the combined use of neck ultrasound (US) and serum Tg and (131)I TBS after TSH stimulation. The follow-up protocol should be adapted to the risk of recurrence. Recent advances in the follow-up of DTC are related to the use of recombinant human TSH (rhTSH) in order to stimulate Tg production and the ultrasensitive methods for Tg measurement. Undetectable serum Tg during TSH suppressive therapy with L-T4 does not exclude persistent disease, therefore serum Tg should be measured after TSH stimulation. The results of rhTSH administration and L-thyroxine therapy withdrawal are equivalent in detecting recurrent thyroid cancer, but the use of rhTSH helps to avoid the onset of hypothyroid symptoms and the negative effects of acute hypothyroidism on cardiovascular, hepatic, renal and neurological function. In low-risk DTC patients serum Tg after TSH stimulation, together with ultrasound of the neck, should be used to monitor persistent disease, avoiding diagnostic TBS which has a poor sensitivity. These recommendations do not apply when Tg antibodies are present in the serum, in patients with persistent or recurrent disease or limited thyroid surgery. Low-risk patients may be considered to be in remission when undetectable Tg after TSH stimulation and negative US evaluation of the neck are present. On the contrary, detectable Tg after TSH stimulation is an indicator in selecting patients who are candidates for further diagnostic procedures.

Biomarkers, Tumor↗

Shading Vita In-ceram YZ substructures: influence on value and chroma, part II.

In this study, the influence of differently shaded substructures made of Y-TZP from different manufacturers (without, with 0.5 mm or 1.0 mm ceramic veneer with Vita VM9 Base Dentin) on the lightness, the saturation, and the color shade (= value, chroma, and hue) was measured and assessed with a spectral photometer (Easy Shade, Vita) on a clinical case in the mouth and on models of different color. Shading substructures made of Y-TZP facilitated adaptation to the basic shade and reduced the layer thickness of the veneer ceramic required to achieve the desired color. This should be done in the future as a matter of routine. In this way, tooth substance can be better conserved when preparing the teeth, and the esthetic result is not diminished. The material used for the production of the working models (plaster or plastic) should be tooth colored and in terms of lightness--analogous to the shading of the substructure--in order to facilitate clinical color measurement and quality control in the laboratory.

Aluminum Oxide↗

Beneficial treatment with risedronate in long-term survivors after allogeneic stem cell transplantation for hematological malignancies.

In this prospective randomized study we evaluated the effect of risedronate, an aminobisphosphonate, on bone mass and turnover in patients who had undergone allogeneic stem cell transplant (SCT) for hematological malignancies. Thirty-four patients (18 females, 16 males, age 32+/-10 years) with bone mineral density (BMD) </=-1.5 SD as a T-score at least 6 months after SCT were treated with calcium 1 g/day and vitamin D 800 IU/day and randomized to receive ( n=17, group 1) or not receive ( n=17, group 2) oral risedronate 5 mg/day. The duration of treatment was 12 months. After 6 months, lumbar BMD increased by 4.4+/-1.6% in patients of group 1 and decreased by 4.3+/-1.5% in those of group 2 ( P<0.05); at the femoral neck, BMD did not change significantly in patients of group 1 (+1.2+/-1.2%), while it decreased in those of group 2 (-4.3+/-2.1%; P<0.05). After 12 months, lumbar BMD further increased (+5.9+/-1.7%, P<0.05), compared to baseline in group 1 and slightly increased (+1.1+/-1.4%) in group 2. No further changes were observed at femoral neck in both groups. In conclusion, treatment with risedronate for 12 months increased BMD significantly at the lumbar spine and prevented further bone loss at the femoral neck in long-term survivors after allo-SCT.

Administration, Oral↗

GH release after GHRH plus arginine administration in obese and overweight women with polycystic ovary syndrome.

Few and unclear data are available in the literature about the relationship between impairment of GH/IGF-I axis and polycystic ovary syndrome (PCOS). This study was aimed to evaluate the basal GH and IGF- levels, and GH release after challenge test in obese and overweight women with PCOS. Thirty patients with PCOS and other 30 healthy women matched for age, body mass index (BMI) and waist-hip ratio (WHR) were studied. Serum follicle-stimulating hormone (FSH), LH, PRL, E2, P, 17OH-progesterone (17OH-P), total T, delta4, DHEA-S, SHBG, GH and IGF-I levels were evaluated in each subject. A GHRH plus arginine challenge test was performed in all subjects. After provocative test, in PCOS and control women the GH levels were significantly (p<0.05) higher in comparison to basal values from 30 min to 120 min. At the same times, a significant (p<0.05) difference was observed between women with PCOS in comparison to healthy women. The mean peak value of GH resulted significantly (p<0.05) lower in PCOS women in comparison to healthy women. The total GH response (area under curve, AUC) to GHRH plus arginine test resulted significantly (p<0.05) lower in PCOS than in healthy women. These findings were statistically significant (p<0.05) also considering the distinction in obese and overweight women. The AUC for GH secretion was significantly lower (p<0.05) in obese in comparison to overweight subjects in the control group, whereas no significant difference was detected between obese and overweight women in the PCOS group. In conclusion, in PCOS women there is a BMI-independent alteration of the GH levels. Further investigations will be necessary to establish the real cause of these data.

17-alpha-Hydroxyprogesterone↗

Early carotid atherosclerosis in normotensive severe obese premenopausal women with low DHEA(S).

The aim of this study was to investigate the direct involvement of hyperinsulinaemia, DHEA and DHEA-S [DHEA(S)] in severe obesity in early carotid atherosclerosis, measured as intima-media thickness (IMT). Seventeen normotensive premenopausal women with very high BMI (43.5 +/- 1.6 kg/m2) were recruited for the study. Six women were also evaluated 12 months after laparoscopic adjustable silicone gastric banding (LASGB). Dietary intake, fasting plasma lipid profile, glycemic and insulinemic response to the OGTT, adrenal secretion, at baseline and after ACTH stimulation test, were measured. IMT, common carotid diameter (CD) and left ventricular mass index (LVMi) were measured by B-mode echotomography. All obese subjects showed higher fasting and stimulated insulin levels, but lower DHEA(S) levels than controls, showing a negative correlation between both fasting and stimulated insulin and DHEA(S), either at baseline or after ACTH testing. IMT was higher (p < 0.05) than controls, with a positive correlation with stimulated insulin (p < 0.05) and a strong negative correlation with DHEA(S) (p < 0.001). In a multiple linear regression analysis, insulin response to OGTT maintained an association with DHEA(S) independent of fasting insulin, while DHEA maintained the association with IMT independent of stimulated insulin (p < 0.0001). In the six patients evaluated 12 months after LASGB, fasting insulin levels decreased, while DHEA(S) levels increased (p < 0.05). In conclusion, an early cardiovascular involvement was detected in this group of severe obese with hyperinsulinaemia and low DHEA(S), even in the absence of other well known CVD risk factors.

Adult↗

Diagnosis and treatment of acromegaly complications.

The Pituitary Society in conjunction with the European Neuroendocrine Association held a consensus workshop to develop guidelines for diagnosis and treatment of the co-morbid complications of acromegaly. Fifty nine pituitary specialists (endocrinologists, neurosurgeons and cardiologists) assessed the current published literature on acromegaly complications in light of recent advances in maintaining tight therapeutic control of GH hypersecretion. The impact of elevated GH levels on cardiovascular disease, hypertension, diabetes, sleep apnea, colon polyps, bone disease, reproductive disorders, and neuropsychologic complications were considered. Guidelines are proposed for effective management of these complications in the context of overall acromegaly control. When appropriate, requirements for prospective evidence-based studies and surveillance database development are enunciated. Effective management of co-morbid acromegaly complications will lead to improved morbidity and mortality in acromegaly.

Acromegaly↗

Experimental infection of calves with bovine viral diarrhoea virus type-2 (BVDV-2) isolated from a contaminated vaccine.

A non-cytopathic strain of BVDV-2 was isolated from a batch of live infectious bovine rhinotracheitis (IBR) vaccine, and inoculated intranasally into four 3-month-old calves. Severe signs of disease developed by days 4 and 6 in three of the calves, free of BVDV and antibodies to BVDV, that had been exposed to the virus. These calves survived the acute phase of the infection and progressively recovered. BVDV was consistently isolated, or the respective viral RNA was detected, in the buffy coats from blood samples collected starting from days 2 or 4 up to days 11 or 14 after the experimental infection. Viral RNA was also detected in sera from these infected calves until the presence in the serum of virus neutralizing antibodies was demonstrated. By contrast, the only calf having pre-existing neutralizing antibodies to BVDV at the start of the study was protected from the disease. No virus was detected at any time after experimental inoculation of this calf. Genomic characterization of the BVDV-2 isolated in cell cultures, or detected in sera from the experimentally infected animals, revealed 100%, homology in the nucleotide sequence with the BVDV-2 detected as a contaminant of the live IBR virus vaccine. These findings provided evidence of the infective nature of the contaminant BVDV-2 and of its potential to generate disease outbreaks when inoculated into susceptible animals.

Animals↗

Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time.

Sildenafil is one of two oral drugs approved for first-line treatment of erectile dysfunction (ED). Anecdotally, some young healthy men who wish to enhance their sexual performance are requesting or abusing sildenafil. In this randomized double-blind, placebo-controlled clinical study, we investigated the effect of sildenafil in young men without ED. A total of 60 young healthy men age 20-40 y with no reported ED were enrolled for this single-dose home-use study. Subjects had used no medication in the 6 months prior to the study. All had been engaged in a stable relationship for at least 3 months. After completing the IIEF-5 questionnaire, patients were randomized in a double-blind fashion to receive either one 25 mg tablet of sildenafil (group 1) taken prior to intercourse, or an identical placebo tablet (group 2). All subjects completed a questionnaire relating to their erectile quality. There were no differences between the two groups in the reported improvement of erection quality, 12/30 sildenafil vs 10/30 placebo (Fisher's test, P=0.79). Sildenafil caused a significant reduction of the postejaculatory refractory time (12/30 vs 4/30) (chi(2) test, P=0.04). Sildenafil does not improve erections in young healthy men. Sildenafil should not be given to young healthy men to improve their erections and patients should be advised against recreational abuse of the drug. In this limited single-dose home study, sildenafil appears to reduce the postorgasmic refractory time. Although controlled studies are needed to evaluate the efficacy of erection-enhancing drugs in premature ejaculation, it is possible that sildenafil might be useful for this indication.

Adult↗

Both maturation and survival of human dendritic cells are impaired in the presence of anergic/suppressor T cells.

T cell suppression is a well established phenomenon, but the mechanisms involved are still a matter of debate. Mouse anergic T cells were shown to suppress responder T cell activation by inhibiting the antigen presenting function of DC. In the present work we studied the effects of co-culturing human anergic CD4+ T cells with autologous dendritic cells (DC) at different stages of maturation. Either DC maturation or survival, depending on whether immature or mature DC where used as APC, was impaired in the presence of anergic cells. Indeed, MHC and costimulatory molecule up-regulation was inhibited in immature DC, whereas apoptotic phenomena were favored in mature DC and consequently in responder T cells. Defective ligation of CD40 by CD40L (CD154) was responsible for CD95-mediated and spontaneous apoptosis of DC as well as for a failure of their maturation process. These findings indicate that lack of activation of CD40 on DC by CD40L-defective anergic cells might be the primary event involved in T cell suppression and support the role of CD40 signaling in regulating both activation and survival of DC.

Apoptosis↗

Standardization of an inactivated H17N1 avian influenza vaccine and efficacy against A/Chicken/Italy/13474/99 high-pathogenicity virus infection.

The minimum requirements for assessing the immunogenicity of an experimental avian influenza (AI) vaccine prepared from inactivated A/Turkey/Italy/2676/99 (H7N1) low-pathogenicity (LP) AI (LPAI) virus were determined in chickens of different ages. A correlation between the amount of hemagglutinin (HA) per dose of vaccine and the protection against clinical signs of disease and infection by A/Chicken/Italy/13474/99 highly pathogenic (HP) AI (HPAI) virus was established. Depending on the vaccination schedule, one or two administrations of 0.5 microg of hemagglutinin protected chickens against clinical signs and death and completely prevented virus shedding from birds challenged at different times after vaccination.

Animals↗

An evaluation of patients with hyperprolactinemia: have dynamic tests had their day?

Except for a few particular conditions, the diagnostic evaluation of hyperprolactinemia is easy since the routine use of magnetic resonance imaging (MRI) scan has permitted to identify even small microadenomas. Other conditions include the identification of large PRL molecular complex, dimers, trimers or polymers of PRL, called "big or big-big PRL", and of PRL autoantibodies and the biochemical finding of "high dose PRL hook effect". Finding elevated serum PRL levels should be considered as the beginning and not the conclusion of a diagnostic evaluation: first, a careful anamnesis should exclude possible physiologic, pharmacologic and organic causes of hyperprolactinemia; second, possibly one laboratory only, undergoing regularly quality controls, should analyze blood samples; serial serum PRL measurements at 0, 30, 60 min is a valuable and simple measure to identify stress-related hyperprolactinemia. In the past two decades several pharmacological tests were used in order to distinguish between small microprolactinomas and "non-tumoral hyperprolactinemia": the controversial results of these tests together with the availability of MRI has excluded all pharmacological tests in the work-up of hyperprolactinemia. MRI is preferred to computed tomography (CT) due to its better definition of very small lesions in the pituitary sella and better anatomical definition prior to surgery. Finally, once the diagnosis of prolactinoma is suspected, patients should be referred to a specialist centre for further assessment and treatment.

Decision Trees↗