Endothelial function in young subjects with vaso-vagal syncope

BACKGROUND

The aim of this study was to determine whether endothelial function and inappropriate peripheral vasomotion have a significant role in the pathogenesis of neurally mediated syncope.

METHODS

In 16 patients (mean age 28.2+/-5.8 years) with previous vaso-vagal syncope and in matched healthy subjects, endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent response to glyceryl trinitrate (GTN), 25 mug, were measured in the brachial artery from high-resolution ultrasonography. Heart rate variability (HRV) analysis at rest and during tilt test was compared between two groups.

RESULTS

In the subjects with positive tilt test, all HRV parameters were significant higher respect to subjects with negative tilt test (P<0.001). The patients with positive tilt test, showed persistent, marked variability of heart rate (HR), due to increased vagal activity with withdrawal sympathetic tone and consequently reduction of blood pressure (BP) (-30.4+/-4.2 mmHg, P<0.001) accompanied by a decrease in HR (-24.3+/-4.5 beats/min, P<0.001) compared to negative tilt test subjects. These findings prove the real presence of vagal hypertone in patients with syncope. In our study, HR reached values lower than 40 beats/min. FMD in patients with neurally mediated syncope were significantly greater than those in controls (respectively, 9.2+/-2.8% vs. 4.6+/-1.4%, P<0.01) whereas no differences were shown in the response to GTN (18.4+/-4.4% vs. 16.1+/-4.2%, n.s.).

CONCLUSIONS

The augmented endothelial function and the abnormal vasodilation of peripheral arteries in association with bradycardia play an important role in the development of vaso-vagal syncope in young subjects.

Effects of systemic glucocorticoid administration on tenocytes

The effects of systemic administration of glucocorticoids (GC) on Achilles tendons of rats was studied. After the animal euthanasia, Achilles tendons were removed in sterile conditions from Sprague Dawley adult female rats to isolate tenocytes. Animals have been daily treated for 8 weeks with 4 mg/kg methylprednisolone or Sham-treated with saline solution. In vitro, cell proliferation (WST-1), extra-cellular matrix (ECM) synthesis (collagen type I, CICP; proteoglycans, PG; and fibronectin, FBN), and transforming growth factor (TGF-beta1) were evaluated at 3 and 7 days of culture. The effect of glucocorticoids (GC) on tenocytes was evident both at 3 and 7 days of culture, and caused a significant decreases in cell proliferation (P<0.01), CICP (P<0.01) and PG synthesis (P<0.01) as compared to NT tenocytes. In conclusion, GC systemic treatment seems to compromise the normal proliferation rate and synthetic activity of cultured tenocytes. This study was helpful in understanding the fundamental biological processes that occur during corticosteroid systemic administration and tenocyte cultures may be used to further study to improve knowledge of these cell behaviour also in the ambit of tendon tissue-engineered therapies.

Bioabsorbable scaffold for in situ bone regeneration

A non-porous poly-DL-lactide tubular chamber filled by demineralised bone matrix (DBM) and bone marrow stromal cells (BMSC) in combination, was evaluated as a scaffold for guided bone regeneration (GBR) in an experimental model using the rabbit radius. The tubular chamber had an internal diameter of 4.7 mm, a wall thickness of 0.4 mm and a length of 18 mm. Autologous BMSC were obtained, under general anaesthesia from rabbit iliac crest and isolated by centrifugation technique. Allogenic DBM was obtained from cortico-cancellous bone of rabbits. In general anaesthesia, a 10-mm defect was bilaterally created in the radii of 10 rabbits. On the right side (experimental side) the defect was bridged with the chamber filled with both BMSC and DBM. On the left side (control side) the defect was treated by positioning DBM and BMSC between the two stumps. At an experimental time of 4 months histology and histomorphometry demonstrated that the presence of a tubular chamber significantly improved bone regrowth in the defect The mean thickness of newly-formed bone inside the chamber was about 56.7+/-3.74% of the normal radial cortex, in comparison with 46.7+/-10.7% when DBM and BMSC without the chamber were placed in the defect, P<0.05). These results confirmed the effectiveness of the chamber as a container for factors promoting bone regeneration.

Thyroid nodule evaluation: what have we really learned from recent clinical guidelines?

Recent guidelines for the evaluation of thyroid nodules clarify the diagnostic algorithm while also reporting important differences. The performance of fine needle aspiration (FNA) for cytological examination follows serum TSH determination and thyroid ultrasonography. Thyroid scintigraphy is recommended following a low TSH value and/or FNA yielding an indeterminate follicular cytology. The use of thyroid ultrasonography is the source of some controversy: though it is recommended as a principal first test, its real-time use to guide FNA ranges from routine to only following an FNA yielding an inadequate or nondiagnostic cytological result. In clinical practice, the proportion of physicians utilizing ultrasonography, scintigraphy and FNA varies and frequently deviates from recommended guidelines. The development of guidelines is necessary to bring about consistency and optimization to the diagnostic work-up of thyroid nodules. It is likely that novel diagnostic procedures, such as molecular markers, large needle aspiration biopsy and thyroid imaging with tracers beyond conventional radioactive iodine or (99m)Tc pertechnetate, will lead to improved performance and implementation of guidelines.

Role of 18F-FDG-PET and PET/CT imaging in thyroid cancer

In patients affected by differentiated thyroid cancer (DTC), the lacking of 131Iodine trapping by metastatic tissue does not allow 131Iodine whole body scintigraphy to visualize matastatic spread as well as the use of 131Iodine therapy to cure such metastatic spread. Prognosis of 131Iodine-negative DTC metastasis, so-called non-functioning metastasis, is significantly worst. In these patients an early diagnosis of non-functioning metastasis and their surgical extirpation remains the optimal therapeutic approach. In this view, a high sensitive localizing imaging different form 131Iodine whole body scintigraphy is required. Ultrasonography is characterized by a relatively high sensitivity in these patients but it is highly operator-dependent and, moreover, it can be used to explore neck alone. Computed tomography (CT) scan and magnetic resonance (MR) imaging are characterized by a relatively low sensitivity even if they are useful to provide the surgeon with anatomical information of the operating basin. Various tumor-seeking radiotracers have been proposed, mainly using SPECT as 201Thallium, 99mTc-Sestamibi and 99mTc-Tetrofosmin with good results. Even more favorable results have been reported with some positron radiotracers, mainly the 18F-FDG with PET and more recently with PET/CT tomographs. The typical indication to performing with examination is the DTC patient previously treated by total thyroidectomy and 131Iodine ablative therapy, with increased serum thyroglobulin (Tg) or anti-thyroglobulin (TgAb) antibodies during follow-up but with negative 131Iodine whole body scintigraphy even obtained after high, therapeutic 131Iodine doses. Several studies in literature have reported high sensitivity (up to 85%) and specificity (up to 95%) of FDG-PET in metastatic DTC patients. The integrated PET/CT fusion imaging systems, seem able to provide some additional advantages over PET alone, mainly related to a better anatomical localization of the hypermetabolic metastatic lesions. A change in the management of DTC patients affected by non-functioning metastatic spread not visualized by other imaging techniques has been reported in 30% of patients. Lastly, the role of PET and PET/CT fusion imaging systems seem to be promising also in patients affected by medullary thyroid carcinoma (MTC), especially for the detection of neck and mediastinal lesions, with a sensitivity superior to the other currently available imaging methods, however the data reported on medullary cancer are little and further studies are needed to elucidate the preliminary promising results.

Spectral Analysis of Skin Blood Flowmotion Before and After Exercise in Healthy Trained and in Sedentary Subjects

Cutaneous blood flowmotion (CBF) can contribute to a reduction in the resistance in skin microvascular networks. The increase of CBF during exercise can improve the capacity of skin microvascular networks to transport and eliminate heat. In order to verify if the physical training could increase the skin blood flowmotion during exercise, we performed spectral analysis of cutaneous forearm laser Doppler signal, before and after acute maximal exercise in 15 healthy trained subjects (TS) and in 15 control sedentary subjects (SS). Within the total spectrum of 0.009 - 2.3 Hz, five frequency intervals of CBF were analysed: 0.009 - 0.02 Hz (endothelial activity), 0.02 - 0.06 Hz (sympathetic activity), 0.06 - 0.2 Hz (vascular myogenic activity), 0.2 - 0.6 Hz (respiratory activity), and 0.6 - 2.3 Hz (heart activity). In basal conditions, no difference between TS and SS was observed in the cutaneous blood perfusion (CBP), expressed in conventional perfusion units (PU), and in the mean value of CBF total spectrum power density (PD), measured in PU/Hz, while the absolute PD of the endothelial and myogenic CBF components was significantly higher (p < 0.05) in TS (0.69 +/- 0.62 PU/Hz and 0.47 +/- 0.43 PU/Hz, respectively) than in SS (0.29 +/- 0.16 PU/Hz and 0.23 +/- 0.16 PU/Hz, respectively). In both TS and SS, acute exercise induced a significant increase of CBP mean value (30.91 +/- 20.28 PU, p < 0.0005 and 16.45 +/- 7.02 PU, p < 0.0005; respectively) and of CBF total spectrum PD (6.65 +/- 4.13 Hz/PU, p < 0.001 and 4.17 +/- 1.86 Hz/PU, p < 0.05; respectively), with a significant difference of these two parameters between the two groups (p < 0.05). After exercise, CBF components regarding endothelial and myogenic activities maintained a higher PD mean value in TS in respect to SS (1.69 +/- 1.34 PU/Hz and 1.59 +/- 0.93 versus 0.91 +/- 0.44 and 0.98 +/- 0.48 PU/Hz respectively, p < 0.05). These findings suggest that physical training is associated with the increase of CBF and particularly on its endothelial and myogenic components in response to exercise. This can favour a greater reduction of resistance in skin microvascular networks during exercise and consequently an increase of its capacity to transport and eliminate heat.

Spectral analysis of laser Doppler skin blood flow oscillations in human essential arterial hypertension

The aim of this study was to investigate whether human essential arterial hypertension (EHT) is associated with modification of the skin blood flowmotion (SBF), which could be a sign of skin microcirculatory impairment. Forearm skin perfusion was measured by laser Doppler flowmetry (LDF) in conventional perfusion units (PU) before and after ischemia in 20 middle-age newly diagnosed EHT untreated patients, in 20 middle-age long standing EHT treated patients and in 30 age and sex matched healthy normotensive subjects (NS). Power spectral density (PSD) of SBF total spectrum (0.009-1.6 Hz), as well of five different frequency intervals (FI), each of them related to endothelial (0.009-0.02 Hz), sympathetic (0.02-0.06 Hz), myogenic (0.06-0.2 Hz), respiratory (0.2-0.6) or cardiac (0.6-1.6) activity, was also measured in PU(2)/Hz before and after ishemia, using Fourier analysis of LDF signal. The three studied groups did not differ in basal and post-ischemic skin perfusion or in basal SBF parameters considered. However, while a significant post-ischemic increase in PSD of total spectrum SBF (P < 0.001) and of its different FI, with the only exception of respiratory FI, was observed in NS, a significsnt post-ischemic increase in PSD was observed only for total spectrum (P < 0.01) and for endothelial FI (P < 0.001) in newly diagnosed EHT patients and only for myogenic FI (P < 0.05) in long standing EHT patients. These findings suggest that the mechanisms which mediate the post-ischemic increment of SBF are perturbed earlier in human EHT than the mechanisms which mediate the skin post-ischemic hyperaemia. The same findings also suggest that the impairment of the endothelial mechanism involved in SBF control occurs by the time in the course of EHT.

Large needle aspiration biopsy and galectin-3 determination in selected thyroid nodules with indeterminate FNA-cytology

Thyroid fine-needle aspiration biopsy (FNA)-cytology is widely used for the preoperative characterisation of thyroid nodules but this task is difficult for follicular lesions, which often remain undefined. We propose a strategy for improving the preoperative characterisation of selected follicular thyroid proliferations, which is based on large needle aspiration biopsy (LNAB) and galectin-3 expression analysis. Eighty-five thyroid specimens were obtained by LNAB (20-gauge needles) from thyroid nodules with indeterminate follicular FNA-cytology. Aspirated material was processed as a tissue microbiopsy to obtain cell blocks for both cyto/histo-morphological evaluation and galectin-3 expression analysis, by using a purified monoclonal antibody to galectin-3 and a biotin-free immunoperoxidase staining method. Preoperative diagnosis was compared to the final histology. LNAB and cell-block technique allow a preliminary distinction between nodules with a homogeneous microfollicular/trabecular structure, as frequently observed in tumours, and lesions with mixed normo-micro-macrofollicular architecture, as observed in goitre. Furthermore, LNAB provides optimal substrates for galectin-3 expression analysis. Among 85 cases tested, 14 galectin-3-positive cases were discovered preoperatively (11 thyroid cancers and three adenomas confirmed at the final histology), whereas galectin-3-negative cases were 71 (one carcinoma and 70 benign proliferations at the final histology). Sensitivity, specificity and diagnostic accuracy of this integrated morphologic and phenotypic diagnostic approach were 91.6, 97.2 and 95.3%, respectively. In conclusion, LNAB plus galectin-3 expression analysis when applied preoperatively to selected thyroid nodules candidate to surgery can potentially reduce unnecessary thyroid resections.

Large-needle percutaneous aspiration biopsy of the testicle in men with nonobstructive azoospermia

Two hundred thirteen testicular specimens of men with nonobstructive azoospermia were obtained by large-needle percutaneous aspiration biopsy. The mean values of the number of seminiferous tubules per histologic section, dimension, weight, and the fraction of biopsies with spermatogenetic cells (53, 0.2 x 0.3 x 0.62 cm, 385 mg, and 63%, respectively) were similar to those obtained by open or other surgical biopsy techniques that were used for assisted fertilization in the same type of patients.

Safety and effects on the lipid and C-reactive protein plasma concentration of the association of ezetimibe plus atorvastatin in renal transplant patients treated by cyclosporine-A: a pilot study

Ezetimibe (E) is a new cholesterol adsorption inhibitor which prevents the adsorption of dietary and biliary cholesterol by binding to a recently described cholesterol transporter. This pilot study was performed to evaluate the safety and the low-density lipoprotein (LDL)-C and C-reactive protein lowering efficacy of atorvastatin (A) and of the association of A plus E in five renal transplant patients with hypercholesterolemia and mild renal functional impairment receiving cyclosporine-A (CsA). Patients received for three periods, each of 3 weeks, A at a dose of 20 mg/day; A at a dose of 10 mg/day and finally, A 10 mg plus E 10 mg daily. The medications were well-tolerated and no important clinical or laboratory (muscle enzyme, creatinine clearance and CsA concentration) abnormalities were observed throughout the study period. A alone lead to target LDL-C values only in two of five patients and did not significantly reduce the mean CRP values. The combination of E plus A produced the lowest lipid levels and significantly reduced CRP mean values and allowed all patients to attain target levels of LDL-C: total cholesterol decreased from 240 +/- 42 (mean +/- S.D.) to 171 +/- 34 mg/dl, LDL-C from 129 +/- 32 to 87 +/- 21 mg/dl, plasma triglycerides from 330 +/- 54 to 194 +/- 71 mg/dl and CRP from 6.2 +/- 1.9 to 3.9 +/- 2.4 mg/l (P < 0.05 for all). This pilot study suggests that the co-administration of E and A at 10 mg/day in renal transplant patients receiving CsA is well-tolerated and effective in reducing important cardiovascular risk factors.

Minimally invasive radioguided parathyroidectomy

We reported here the data on minimally invasive radio-guided parathyroidectomy (MIRP) in a large group of 253 patients enrolled from the whole series of 355 consecutive patients affected by primary hyperparathyroidism (P-HPT) referred to our center. On the basis of preoperative imaging including Sestamibi scintigraphy and neck ultrasound (US), 263 patients (74% of the whole series) with evidence of a solitary parathyroid adenoma (PA) and a normal thyroid gland were addressed to MIRP and in 253 (96%) of them this minimally invasive neck exploration was successfully performed. The MIRP protocol developed in our center consisted of a very low 1 mCi Sestamibi injection in the operating room a few minutes before the start of intervention, thus minimizing the radiation exposure dose to the patient and personnel. No major intraoperative complication was recorded in patients treated by MIRP and only a transient hypocalcemia in 8.5% of cases. The mean duration time for MIRP was 35 min and the mean hospital stay 1.2 days. Local anesthesia was also performed in 62 patients, 54 of whom were elderly patients with concomitant invalidating diseases contraindicating general anesthesia. No HPT relapse was observed during subsequent follow-up. The gamma probe was used also during bilateral neck exploration in the group of 92 patients excluded from MIRP. The most frequent cause of exclusion from MIRP in our series was the presence of concomitant Sestamibi avid thyroid nodules (68.5% of cases) that can give false positive results at radio-guided surgery. In conclusion, MIRP is an effective treatment in patients with a high likelihood of a solitary PA and a normal thyroid gland at scintigraphy and US so that an accurate preoperative localizing imaging is required for MIRP. A low 1 mCi Sestamibi dose appears sufficient to perform MIRP. Patients with concomitant Sestamibi avid thyroid nodules should be excluded from MIRP.

Acute effects of hemodialysis on left ventricular function evaluated by tissue Doppler imaging

Evidence exists that left ventricular function is impaired in chronic uremic patients. During hemodialysis (HD) treatment, myocardium undergoes electrolyte, hemodynamic and neuro-humoral stress; however, data about the acute changes on ventricular function are controversial. Aim of the present study was to evaluate the effect of a single hemodialysis session on left ventricular (LV) systolic and diastolic function using pulsed tissue Doppler imaging (TDI) sampled by echocardiography. The study group included 20 uremic patients (17 males, aged 51+/-13 yrs) on maintenance HD, free from clinically overt cardiac dysfunction who underwent echocardiography with pulsed TDI 30 min prior and 30 min after a HD session. TDI was performed by placing the sample volume in the center of the basal lateral segment and the basal interventricular septum in the apical four-chamber view. Myocardial systolic wave (S(m)) and early (E(m)) and atrial (A(m)) diastolic waves were measured. On standard sonography examination, no significant changes in LV systolic function parameters were observed after HD, but the indices for LV diastolic function deteriorated significantly (peak E, 75.4+/-11.2 vs. 58.8+/-12.5 cm/s, P<0.01; E/A ratio, 1.0+/-0.3 vs. 0.8+/-0.2, P<0.01). However, regarding TDI measures following HD, the patients exhibited a lower S(m) peak (septum: 7.6+/-1.1 vs. 5.9+/-0.8 cm/s; lateral wall: 7.7+/-1.7 vs. 6.8+/-1.2 cm/s, P<0.001), a lower E(m) peak (septum: 8.3+/-1.6 vs. 6.3+/-1.7 cm/s; lateral wall: 10.2+/-2.4 vs. 7.1+/-1.9 cm/s, P<0.001), and a reduced E(m)/A(m) ratio (septum: 1.0+/-0.4 vs. 0.7+/-0.2; lateral wall: 1.2+/-0.5 vs. 0.7+/-0.2, P<0.001, respectively), as compared to pre-HD parameters. Of interest, peak E(m), and E(m)/A(m) ratio of the lateral wall were negatively related to ultrafiltration rate (r = -0.60, P<0.05 and -0.69, P<0.01, respectively). Our data indicate that a single hemodialysis session is associated with acute deterioration of diastolic and systolic parameters of myocardial function, as assessed by TDI. These reversible changes could be considered as a cardiac stunning that seems to be related to the ultrafiltration rate and then to the interdialysis weight gain. These findings suggest that low ultrafiltration volume and/or limited interdialytic weight gain are cardioprotective measures in hemodialysis patients.

C-reactive protein in patients on chronic hemodialysis with different techniques and different membranes

In hemodialysis patients, C-reactive protein (CRP), an acute-phase reactant, is a sensitive and independent marker of malnutrition, anemia, and cardiovascular mortality. The aim of the present study was to evaluate CRP levels in plasma samples from long-term hemodialysis patients on different extracorporeal modalities and dialyzed with different membranes, at baseline and after 6 months. Two hundred and forty-seven patients were recruited in eight hospital-based centers. All patients had been on their dialytic modality for at least 3 months and were prospectively followed in their initial dialytic modality for 6 months. Patients were treated with conventional bicarbonate dialysis (N = 127) or hemodiafiltration (N = 120). Patients treated with conventional bicarbonate dialysis were dialyzed with different membranes: Cuprophane (N = 51), low-flux cellulose modified membrane (N = 37) and synthetic membranes (N = 39). Hemodiafiltration was performed in post-dilution mode with polysulfone (N = 66) and polyacrylonitrile (N = 54) membranes. Analysis of baseline CRP values in the clinically stable patients showed that an unexpectedly high proportion (47%) of the patients had CRP values higher than 5 mg/l (upper limit in normal subjects). The mean +/- S.D. CRP values were significantly higher (P < 0.05) in hemodiafiltration with infusion volumes < 10 l per session (14.6+/-3.1 mg/l) than in standard hemodialysis (5.1 +/- 2.1 mg/l) and hemodiafiltration with infusion volumes > 20 l per session (4.9 +/- 2.1 mg/l). These values did not significantly change after 6 months of follow-up. Concerning the membranes, the highest levels of CRP were observed in patients dialyzed with Cuprophane with a significant increase from 15.1 +/- 3.6 to 21.2 +/- 3.1 mg/l after 6 months (P < 0.05); a significant reduction of CRP levels was observed in patients dialyzed with polysulfone in the same follow-up period (from 13.5 +/- 2.9 to 8.1 +/- 2.4 mg/l; P < 0.05). The CRP increase following low volume HDF can be related to back-filtration of bacterial derived contaminants.; moreover, an important effect on CRP of the hemodialysis membrane is observed and new synthetic membranes can be used to decrease these levels.

Biomolecular markers of breast cancer

Here, the structure, function, biological and pathological significance and clinical utility of the principal biomolecular markers of breast cancer is reviewed. Each marker was scored for clinical utility using a recently developed tumor marker utility grading system (TMUGS). Among the tissue markers, ERs and PRs are important prognostic/predictive factors and the only tissue markers routinely determined. ER cross-talks with other growth factors while co-regulatory factors enhance (co-activators) or decrease (co-repressors) its transcriptional activity. C-erbB-2 and Ki67/MIB-1 select for adjuvant chemotherapy a subgroup of lymph-node negative patients at a high risk of relapse. Monoclonal antibodies (trastuzumab, gefitinib, erlotinib and bevacizumab) targeting tissue markers and involved in tumor growth and metastasization (EGFR, C-erbB-2, VEGF) have been developed; they showed therapeutical single agent activity as well as potent synergy with chemotherapy agents in metastatic cancer. Among circulating markers, some are potentially useful in the early detection and monitoring of metastatic disease; nevertheless, none is routinely recommended. To suspect distant metastases, CEA-TPA-CA15.3 panel attained accuracy of about 90%. ECD HER2-neu, p53 and nucleophosmin antibodies seem suitable candidates for different associations. Preliminary observations suggest that an early detection with tumor markers and successive treatment of relapses significantly prolongs disease-free and overall survival in selected patients. In conclusion, biomolecular markers are improving understanding of biology and management of breast cancer.

Protective effect of L-propionylcarnitine in chronic cyclosporine-a induced nephrotoxicity

Cyclosporine (CyA) is an immunosuppressive agent used after solid organ transplantation, but its clinical use is limited by side effects, the most important of which is nephrotoxicity. In a previous work we demonstrated that L-propionylcarnitine (L-PC), a propionyl ester of L-carnitine, is able to prevent CyA-induced acute nephrotoxicity reducing lipid peroxidation in the isolated and perfused rat kidney. CyA administration was associated with a dose dependent increase in renovascular resistance prevented by a pretreatment with L-PC. The aim of the present study was to confirm L-PC protective effect, previously described in vitro, in an in vivo rat model. Chronic nephrotoxicity study was carried out for 28 days. L-PC was administered (i.p. 25 mg/kg b.w.) since the first day, while CyA treatment was performed for the last 21 days (by oral administration 25 mg/kg b.w.). We demonstrate that L-PC was able to significantly lower blood pressure in CyA treated animals and to prevent CyA induced decrease in creatinine clearance. Moreover renal tissue analysis revealed that L-PC was able to reduce lipid hydroperoxide content and morphological abnormalities associated to chronic CyA administration. In conclusion our study demonstrated for the first time in vivo that L-PC protects against functional and tissue damage associated to chronic CyA administration.

Effect of chronic aerobic exercise on cutaneous microcirculatory flow response to insulin iontophoresis and to ischemia in elderly males

The aim of this study was to assess whether chronic aerobic exercise can favourably influence the vascular activity of insulin in elderly subjects. We measured in arbitrary units (A. U.) the cutaneous blood flow basally and in response to iontophoresis of insulin, by the means of a Laser Doppler flowmeter, on the right arm of 10 elderly athletes (10 males, aged 65 +/- 6 years) and of 10 sex- and age-matched sedentary subjects. The cutaneous blood flow response to ischemia was also explored in the right leg of the same subjects by means of the same instrument. No significant differences in cutaneous arm and leg blood flow were observed basally between athletes and sedentary subjects (7.25 +/- 2.65 A. U. versus 6.35 +/- 4.04 A. U. and 9.74 +/- 5.11 A. U. versus 9.41 +/- 6.40 A. U., respectively). Cathodal iontophoresis (six poulses of 0.1 mA each for 20 s, with 40-s interval between stimulations) of regular insulin (0.1 ml Humulin R 100 IU/ml diluted 1/10 with 0.9 % saline) induced a significant increase of cutaneous blood flow in both groups (p < 0.01 in athletes, p < 0.01 in sedentary subjects). However the maximal cutaneous blood flow response to insulin was higher in athletes than in sedentary subjects (24.69 +/- 13.34 A. U. versus 14.33 +/- 7.73 A. U., respectively, p < 0.05) as well as the curve of the net blood flux response to insulin iontophoresis (% change from baseline in response to insulin minus % change from baseline in response to saline iontophoresis) (p < 0.001 ANOVA for repeated measures). After ischemia there was a significant increase of leg cutaneous blood flow in both groups (p < 0.001 in athletes and in sedentary subjects) with higher blood flow response in athletes than in sedentary subjects (38.18 +/- 17.08 A. U. versus 26.01 +/- 6.39 A. U., respectively, p < 0.05). The time reached from the release of ischemia to peak-flow was significantly longer in sedentary subjects than in athletes (43.5 +/- 28.5 s versus 20.0 +/- 9.3 s, p < 0.05, respectively). These results suggest that chronic aerobic exercise increases insulin vasodilatory activity and improves endothelial function in elderly subjects.

Effect of epirubicin-based chemotherapy and dexrazoxane supplementation on QT dispersion in non-Hodgkin lymphoma patients

BACKGROUND AND OBJECTIVE

Aim of the present study was to assess the effect of epirubicin-based chemotherapy on QT interval dispersion in patients with aggressive non-Hodgkin lymphoma (NHL), and the effect of dexrazoxane supplementation. Prolongation of QT dispersion may not only represent a sensitive tool in identifying the first sign of anthracycline-induced cardiotoxicity, but it may serve also in identifying patients who are at risk of arrhythmic events.

METHODS

Twenty untreated patients, <or=60 years of age with newly-diagnosed aggressive NHL, eligible for a treatment with epirubicin-based chemotherapy were selected for the study. The patients were randomly allocated in two subgroups (N=10) to receive or not dexrazoxane hydrochloride (400 mg/m(2)) after epirubicin infusion. The patients underwent 12-lead electrocardiogram (ECG) before and after epirubicin infusion and after dexrazoxane supplementation. QT dispersion was defined as the difference between the maximum and the minimum QT interval occurring in any of the 12 ECG leads, corrected (QTc) for heart rate.

RESULTS

All the 20 patients showed increased QT dispersion (44.3 +/- 8.4 vs. 68.4+/-11.4 ms, P<0.001) and QTc dispersion (46.2 +/- 6.2 vs. 72.2 +/- 8.4, P<0.001) after chemotherapy infusion. The 10 patients who underwent supplementation with dexrazoxane exhibited a significant reduction of QT dispersion (67.4 +/- 8.1 vs. 49.5 +/- 4.2 ms, P<0.001) and QTc dispersion (71.2 +/- .7 vs. 51.4 +/- 4.3 ms, P<0.001), while the 10 patients not supplemented with dexrazoxane did not (QT dispersion: 69.3 +/- 7.6 vs. 64.2 +/- 6.9 ms; QTc dispersion: 72.8 +/- 8.1 vs. 67.3 +/- 7.2 ms, ns).

CONCLUSIONS

Epirubicin-based chemotherapy causes an early increase of the QT and QTc dispersion, which is attenuated by dexrazoxane supplementation. Therefore, dexrazoxane can reduce the arrhythmic risk in patients treated with epirubicin.

Effects of pulsed electromagnetic fields on articular hyaline cartilage: review of experimental and clinical studies

Osteoarthritis (OA) is the most common disorder of the musculoskeletal system and is a consequence of mechanical and biological events that destabilize tissue homeostasis in articular joints. Controlling chondrocyte death and apoptosis, function, response to anabolic and catabolic stimuli, matrix synthesis or degradation and inflammation is the most important target of potential chondroprotective treatment, aimed to retard or stabilize the progression of OA. Although many drugs or substances have been recently introduced for the treatment of OA, the majority of them relieve pain and increase function, but do not modify the complex pathological processes that occur in these tissues. Pulsed electromagnetic fields (PEMFs) have a number of well-documented physiological effects on cells and tissues including the upregulation of gene expression of members of the transforming growth factor beta super family, the increase in glycosaminoglycan levels, and an anti-inflammatory action. Therefore, there is a strong rationale supporting the in vivo use of biophysical stimulation with PEMFs for the treatment of OA. In the present paper some recent experimental in vitro and in vivo data on the effect of PEMFs on articular cartilage were reviewed. These data strongly support the clinical use of PEMFs in OA patients.

Generalised wavelet analysis of cutaneous flowmotion during post-occlusive reactive hyperaemia in patients with peripheral arterial obstructive disease

The purpose of the present study was to assess whether the generalised wavelet analysis (GWA) of the leg cutaneous laser Doppler (LD) flowmotion waves recorded during baseline (Bsl) and after skin post-occlusive hyperaemia (POH) can provide information on the leg cutaneous microcirculatory adaptation to stage II peripheral arterial obstructive disease (PAOD). With this aim the flowmotion was characterised in 20 healthy subjects (HS) and 20 stage II PAOD patients by GWA of LDF tracings during Bsl and POH test. The vascular endothelial and smooth muscle function was also evaluated exploring the arm skin vasodilatory response to iontophoretically delivered acetylcholine (Ach) and sodium nitroprusside (SNP) using LD. During Bsl there was no significant difference in leg skin perfusion between HS and PAOD patients (7.3+/-5.6 vs. 5.8+/-2.9 AU, respectively). PAOD patients revealed higher peak powers in the frequency interval of 0.007-0.02 Hz (120+/-82 vs. 85+/-62 AU(2)/Hz; P < 0.05), 0.02-0.06 Hz (116+/-128 vs. 63+/-48 AU(2)/Hz, respectively; P < 0.05) and 0.06-0.2 Hz (39+/-49 vs. 14+/-10 AU(2)/Hz; P < 0.05). These flowmotion frequencies are related to vascular endothelium activity, sympathetic activity and vessel wall myogenic activity, respectively. During POH the mean peak power of the flowmotion waves increased significantly (P < 0.05) in HS respect to Bsl with the only exception of the 0.02-0.06 Hz band. In the PAOD patients, compared to Bsl the amplitude of the flowmotion waves did not significantly change during POH. In addition, the PAOD patients presented an increased time from release to peak-flux (18.25+/-15.5 vs. 2.16+/-1.28 s, respectively; P < 0.05), an increased time from release to recovery of the basal perfusion (90.26+/-39.14 vs. 26.55+/-14.05 s, respectively; P < 0.05) and a lower slope of the POH curve (10+/-15 vs. 54+/-17 degrees , respectively; P < 0.05), compared with HS. The cutaneous arm vasodilatory response to Ach and to SNP was reduced in PAOD patients in comparison with HS (P < 0.001). In conclusion, our findings showed an increased amplitude of the frequency interval 0.007-0.02, 0.02-0.06 and 0.06-0.2 Hz during Bsl in PAOD patients which did not change during the POH test. All data suggest that in stage II PAOD patients the leg skin perfusion is not impaired during Bsl because of a compensatory mechanism related to increased endothelial, myogenic and sympathetic activities. However during reactive hyperaemia these mechanisms appear to be exhausted in accordance with the reduced vasoreactivity to Ach and SNP.

Controversies in diagnostic approaches to the indeterminate follicular thyroid nodule

In this paper we review the controversies in diagnostic approaches to follicular thyroid nodules with indeterminate cytology. The authors consider some of the controversies surrounding the indeterminate follicular thyroid nodule, including the definition and the postoperative outcome. Among the techniques that may improve preoperative diagnostic accuracy are large needle aspiration biopsy and immunohistochemistry for galectin-3.

Secondary hyperparathyroidism is associated with vitamin D receptor polymorphism and bone density after renal transplantation

Immunosuppresive treatment and secondary hyperparathyroidism (SHPT) are considered among the most important pathogenetic factors for post-renal transplant bone disease. The aim of this study was to investigate the relationships among vitamin D receptor (VDR) gene polymorphism, parathyroid hormone (PTH) levels and bone density in renal transplant recipients. We enrolled 75 patients (50 male and 25 female, mean age 47+/-11 years) who had undergone kidney transplantation 53+/-4 months before. All patients underwent an evaluation of the main biochemical parameters of bone metabolism as well bone densitometry. VDR alleles were typed by a PCR assay based on a polymorphic BsmI restriction site. When patients were categorized according to the VDR genotype (BB, Bb, bb), serum creatinine and the cumulative doses of immunosuppressive drugs were similar across the groups. PTH levels higher than 80 pg/ml were found in 53.6% of the patients, with the highest values being detected in the bb VDR genotype (P<0.05). PTH was significantly correlated to urinary NTx values. Bone density was low in the whole population; however, spinal bone density was lower in the bb subgroup (P<0.02). In the whole population, only PTH (P<0.05) and body mass index (P<0.01) were independent predictors of spinal bone density. Grouping patients by the VDR gene polymorphism, only PTH continued to be an independent predictor of spinal bone density in the bb allele subgroup (R(2) Adj.=0.17). We can conclude that the VDR genotype polymorphism affects bone density of renal transplant recipients via its effects on the severity of SHPT.

Epidemiological and clinical features of 139 patients with tuberculosis at a teaching hospital in Italy (Pisa, 1996-2000)

In order to describe epidemiologic and clinical features of patients with tuberculosis (TB) identified recently in the hospital of Pisa (Tuscany, Italy), a retrospective study of all cases of TB notified to the Local Public Health Service during January 1996-December 2000 was performed. The diagnosis of TB was made following the criteria of the WHO. A total of 139 patients affected by TB were identified. Diagnosis was microbiologically proved in 81 patients. Mean age was 53.8+/-20.5 S.D. yrs. Thirty-five (25.2%) patients were extra European community citizens (mostly from Africa). The incidence of TB (N/100.000) was 8.4 in 1996 and 6.8 in 2000. Sixty-eight point three per cent of patients had pulmonary TB, 24.5% extrapulmonary and 7.2% mixed TB. The rate of extrapulmonary TB was 15.9% and 39.2% in the 1996-98 and in the 1999-2000 periods, respectively (p = 0.002). Extrapulmonary TB was more frequent in extra European community citizens (42.8%) than in Italian ones (18.3%), p = 0.003. Seven patients were presenting also advanced HIV infection. Microscopic examination for acid fast bacilli in sputum or bronchial secretion resulted negative in 17.4% of proved pulmonary TB (positive culture for Mycobacterium tuberculosis). The chest x-rays showed pleural effusion in 19 patients. Pulmonary cavitation was documented in 15 patients with negative chest x-rays. Fever was not present in 42.4% of the patients at the moment of diagnosis. Three point eight percent of the isolated strains of M. tuberculosis were in vitro multidrug-resistant. The data presented showed an important rate of TB in Pisa. We have yet to understand if the decreased rate observed in 2000 represents a new trend as reported in other North American and European countries. The rate of extrapulmonary TB shows a trend to increase accordingly to recent literature. The isolation rate of multidrug-resistant strains of M. tuberculosis in Pisa seems to be similar to the rates reported in other areas of Europe.

Inflammatory mediators and eosinophilia in atopic and non-atopic patients with nasal polyposis

Nasal polyps are characterized by eosinophilic infiltration and presence of inflammatory mediators, such as total IgE, eosinophil cationic protein (ECP) and cytokines. The role of atopy in nasal polyp pathogenesis is still unclear. Therefore, we evaluated serum IgE levels, nasal mucus concentrations of ECP and cytokines and the number of infiltrating eosinophils in nasal tissue of polyps from atopic and non-atopic patients. Samples were obtained from a randomized population of 31 patients with nasal polyposis having endonasal sinus surgery and of 13 control subjects undergone corrective surgery of the nasal septum. On the basis of medical history of allergy, positive skin-prick tests and total IgE levels, patients with polyposis were divided in atopic (n = 13) and non-atopic (n = 18) patients. We determined levels of IgE in blood, ECP and cytokines (IL-4, IL-6, IL-8, IFN-gamma and IL-2) in nasal mucus, and number of infiltrating eosinophils in nasal tissue. The concentrations of total IgE, ECP, IL-4 and IL-8 and eosinophilia were significantly higher in all patients with nasal polyps compared with controls. Inside, all patients with nasal polyposis showed lower levels of IL-6, IFN-gamma and IL-2 compared with controls. The atopic patients showed significant differences when compared with non-atopic patients for the higher concentrations of total IgE (698.80+/-322.24 vs. 279.63+/-234.11; P < 0.0001) and IL-8 (1437.2 pg/ml+/-1250.7 vs. 605.5 pg/ml+/-481.1; P < 0.015). These findings suggest that inflammation still remains the major factor in the etiology of nasal polyposis and show different levels of inflammatory mediators into atopic and non-atopic patients.

Skin blood flowmotion response to insulin iontophoresis in normal subjects

In order to explore the mechanisms directly involved in the insulin vasodilatory activity, we studied skin blood flowmotion by means of spectral analysis of the skin forearm laser Doppler (LD) signal registered before and after iontophoresis of insulin in saline (I.S.) (0.1 ml Humulin R 100 IU/ml diluted 1/10 in 0.9% saline) or pure saline (P.S.) (0.1 ml of 0.9% saline) in twenty normal subjects. Skin LD blood perfusion was also measured in conventional perfusion unit (PU; 1 PU=10 mV). Using a Fast Fourier transform algorithm, power density (PD) of the total flowmotion spectrum, from 0.009 to 1.6 Hz, was measured in PU/Hz. Power density of five skin flowmotion frequency intervals (F.I.) within 0.009-0.02 Hz, 0.02-0.06 Hz, 0.06-0.2 Hz, 0.2-0.6 Hz and 0.6-1.6 Hz (referred to endothelial, sympathetic, myogenic, respiratory and heart activity, respectively) was also measured in PU/Hz. The mean skin LD perfusion increment (expressed as percent change from baseline) was significantly higher after I.S. than after P.S. (P<0.001, ANOVA for repeated measures). Skin flowmotion total spectrum mean PD value significantly increased following iontophoresis of both P.S. (from 1.06+/-0.62 to 1.86+/-0.94 PU/Hz, P<0.005) and I.S. (from 1.07+/-0.92 to 2.39+/-1.73 PU/Hz P<0.00005), however, the mean PD increment was significantly higher after I.S. than after P.S. (1.27+/-0.98 PU/Hz versus 0.69+/-0.67 PU/Hz, P<0.05). Only the flowmotion component referred to myogenic activity showed a percent PD increase from baseline significantly higher in response to I.S. than to P.S. iontophoresis (114.5+/-21.8% versus 58.8+/-17.9%, respectively, P<0.05). These findings show that insulin has a vasodilatory activity on skin microvascular district. The higher increase of total blood flowmotion PD and particularly of the component related to the myogenic activity in response to insulin iontophoresis suggests that the cutaneous vasodilatory activity of insulin is, in part, related to an important action of this hormone on skin microvascular smooth muscle.