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Biomedical subjects

P Zamboni

Publications and source records attributed to P Zamboni.

At least 19 recordsLinked to original sources
PubMed2006

Exercise capacity and circulating endothelial progenitor cells in hemodialysis patients.

Mobilization of circulating endothelial progenitor cells (EPCs) is increased after acute exercise and training. This study aims to evaluate whether, in a low performance population, EPC levels may be related to exercise capacity in steady state conditions. Study population consisted of sixteen hemodialysis patients. The distance walked in the 6-minute walking test (6 MWD) and the maximal speed attained in an incremental treadmill test were used to assess the exercise capacity. Physical functioning was measured by the scale on the SF36 questionnaire. Quantification of peripheral blood CD34(+) cells and enumeration of EPCs, assessed as CD34(+) cells coexpressing AC 133 and vascular endothelial growth factor receptor-2, were performed. Hemoglobin concentration, white blood cells, high-sensitivity C-reactive protein, total cholesterol, and triglycerides were measured. Statistical analysis examined the relationship between blood progenitors cells versus performance parameters, laboratory parameters, age, body mass index, hemodialysis duration, and erythropoietin therapy. Univariate analysis revealed a significant association between percentage values of EPC and performance parameters only: 6 MWD (r=0.720; p=0.0017), maximal treadmill speed (r=0.721; p=0.0016), and physical functioning score (r=0.506; p=0.0453). A similar statistical association between EPC absolute values and performance parameters was found. No correlation between CD34 (+) and any parameter under study was observed. Multivariate analysis indicated 6 MWD as the most significant independent factor associated with EPC level. EPC percentage value was significantly lower (p=0.0087) in the worse (6 MWD < 300 m, n=8) than in the better performing group (6 MWD > 300 m, n=8). In a group of renal patients, mobilization of EPCs was related to the degree of exercise capacity, suggesting a possible connection with the cardiovascular risk in low performance populations limited by chronic diseases.

Aged↗
PubMed2006

Acute vascular events and electrolytes variations in elderly patients.

Alterations in electrolyte balance have been claimed to play a role in the pathophysiology of coronary heart disease; however, the relationship between the electrolyte pattern and other clinical variables immediately after an acute vascular event is unclear. The aim of the present study was to test whether electrolyte and microelement changes characterize the acute phase in patients with different degrees of glucose tolerance admitted to the hospital shortly after an acute cardiovascular or cerebrovascular ischemic event. Two hundred consecutive patients with either myocardial infarction or stroke (SP group), stratified by degree of glucose tolerance, were studied within six hours of admission, and compared against 125 patients admitted for conditions other than acute vascular ischemia (CP). Routine laboratory parameters and serum Na, K, Cl, Mg and Ca concentrations were determined in all patients and compared to those recorded within six months before the admission. Relative to CP and independently of confounding factors including glucose tolerance status, the SP group showed significantly higher plasma glucose and insulin concentrations, higher creatinine and a modified serum electrolyte pattern characterized by significantly lower potassium and magnesium levels and by hypercalcemia and hyperphosphatemia. Irrespective of glucose tolerance, the first hours following an acute vascular event are characterized by marked insulin resistance with a consistent shift in the serum electrolyte pattern. This pattern is the physiological consequence of the attendant compensatory hyperinsulinemia. Its significance for the evolution of ischemic damage remains to be established.

Aged↗
PubMed2006

Hemodynamics of the sapheno-femoral complex: an operational diagnosis of proximal femoral valve function.

AIM: A significant relationship between great saphenous vein (GSV) caliber at the thigh and function of the terminal valve of the sapheno-femoral junction (SFJ) has already been demonstrated. Yet, the function of the proximal common femoral valve (FV), which is missing in 20-24% of cases, might also play a significant role in SFJ reflux. The aim of this paper was to verify whether GSV caliber also predicts the function/presence of FV. METHODS: Using a high-resolution duplex scanner we selected 572 GSVs showing clear-cut SFJ incompetence. Then, by positioning the probe on the inguinal skin fold and orientating the probe upward, we tested FV function. Valve incompetence was diagnosed when a retrograde flow lasting longer than 0.5 s was elicited by both calf squeezing with sudden release and Valsalva maneuver, with the patient standing. Finally, in all patients we measured GSV caliber 15 cm below the groin in the standing position. RESULTS: GSV caliber =7 was not predictive of FV function/presence (51.9% competence vs 48.1% incompetence/absence). In contrast, GSV caliber < or = 6 mm and GSV caliber > or = 8 mm were highly predictive of FV competence and incompetence/absence, respectively (sensibility 98.6%, specificity 80.4%, positive predictive power 88.2%, negative predictive power 97.4%, diagnostic accuracy 91.3%). CONCLUSIONS: Our data strengthen the relationship between GSV caliber at the thigh and hemodynamics of the whole sapheno-femoral complex, including in this definition the FV also.

Adult↗
PubMed2005

Sciatic nerve varices.

OBJECTIVE(S): To describe patients presenting with sciatic nerve varices (SNV), presenting pitfalls in diagnosis and management. DESIGN: Case series. METHODS: Patients were investigated using duplex ultrasonography pre-operatively in three cases. Treatment was undertaken both by surgery and by foam sclerotherapy. RESULTS: Clinically, SNV appeared just below the popliteal skin crease, lateral to the small saphenous vein (SSV). In two cases SNV occurred alone, in two further cases SNV occurred in conjunction with varices from other sources. Symptoms of 'sciatic' pain were present in all. Foam sclerotherapy (1% Polidocanol) was undertaken in one case with a varix. Complete obliteration of the vein and resolution of all symptoms was achieved at the 1-month follow-up examination. Surgical management was used in the other cases. CONCLUSION: The sciatic nerve vein follows the fibular saphenous nerve (lying superficial to the fascia in the leg). This nerve arises from the common peroneal nerve (in the popliteal fossa), and is a major branch of the sciatic nerve. Varices of the associated vein appear to be the result of a dysplasia. This condition may be more common than is currently recognised.

Humans↗
PubMed2004

Speed rather than distance: a novel graded treadmill test to assess claudication.

OBJECTIVE: To evaluate a new treadmill test, determining pain threshold speed (PTS) for use in assessment and measuring rehabilitation of patients with intermittent claudication. METHODS AND DESIGN: Twenty-nine patients with claudication were evaluated, and the ankle-brachial index (ABI) was assessed. PTS was determined with a treadmill protocol based on level walking, low starting speed, and progressive increments at a predetermined distance up to the onset of pain. Repeatability and equivalence with a time-based protocol were verified. PTS was compared to pain-free walking distance, 6-minute walking distance, and ABI. RESULTS: PTS was measured in all patients (3.6+/-1.1 km/h). Repeatability and equivalence between established tests were demonstrated. PTS showed a significant correlation with pain-free walking distance (r=0.833; P=0.0001), with 6-minute walking distance (r=0.724; P=0.005), and with ABI in the more ischemic limb (r=0.641; P=0.0001). CONCLUSIONS: PTS is a reliable parameter that correlates well with other established measures. It is useful for determining the degree of functional handicap and for designing and guiding rehabilitation protocols.

Aged↗
PubMed2004

The "T" vein of the leg.

BACKGROUND: We frequently observe a tributary of the saphenous vein with the origin in the saphenous compartment of the medial aspect of the upper third of the leg. It runs transversally in the interfascial compartment toward the lateral aspect of the leg. Constantly it feeds by reflux varicose veins clinically visible in the paratibial region and/or in the lateral aspect of the leg. For the peculiarity of its anatomical shape as well as duplex appearance, we defined it as the "T" vein. OBJECTIVES: To assess how frequently the "T" vein of the leg is involved in varicose networks. METHODS: A total of 218 consecutive patients affected by primary varicose veins have been evaluated by the means of duplex scanning. We assessed both the presence of the above-mentioned tributary and the frequency of its hemodynamic involvement in the varicose network. RESULTS: In 15 of 218 cases (7%) we demonstrated the above-mentioned tributary with an interfascial length ranging between 5 and 12 cm involved in varicose networks. CONCLUSIONS: The anterior tributary of the saphenous vein of the anterolateral aspect of the leg is a neglected clinical entity, whose existence is important to know for the treatment of varicose veins of the lateral aspect of the leg.

Adult↗
PubMed2004

Hemodynamics of the sapheno-femoral junction. Patterns of reflux and their clinical implications.

AIM: The detection of reflux elicited by the compression/release test with the PW Doppler sample at the level of the sapheno-femoral arch might not be sufficient by itself to diagnose the incompetence of the whole sapheno-femoral junction (SFJ). The aim of this study was to further refine the diagnosis by positioning the PW Doppler sample at different levels of SFJ and eliciting reflux both by squeezing and with the Valsalva manoeuvre. In addition, the relationship of the findings with the vein diameter was taken into consideration. METHODS: By using a high resolution duplex scanner, 1 294 great saphenous veins (GSV) found to be incompetent by the compression/release test at duplex investigation of the saphenous arch, were also tested at the same level by the Valsalva manoeuvre. Subsequently, the tests were repeated by positioning the PW Doppler sample at the femoral side of the terminal valve, at the saphenous arch tributaries, and at the pre-terminal valve level. Furthermore, the GSV diameter in the standing position was measured at 15 cm from the groin in all patients, and correlated with the hemodynamic patterns found at the junction level. RESULTS: Comparing to compression/release test at the level of the saphenous arch, the Valsalva manoeuvre was negative in 259 (20%) lower limbs and positive in 1 035 (80%). Among the 1 294 GSV found to be incompetent at compression/release test at the level of the saphenous arch, only 710 (55%) lower limbs showed incompetence of the terminal valve. A total of 124 patients (10%), presenting with a competent terminal valve but with a positive Valsalva manoeuvre in the arch, showed a downward flow from a pelvic tributary of the GSV. Finally, a significant statistical correlation between the presence of a competent terminal valve and a GSV diameter <5 mm has been found (p<0.001). CONCLUSION: Our data show that the detection of reflux elicited by compression/release test at the level of the saphenous arch is insufficient to diagnose the incompetence of the terminal valve. Our results, together with the correlation between the saphenous trunk diameter at the thigh and the competence or the incompetence of the terminal valve, present significant clinical implications when sapheno-femoral surgical disconnection is contemplated.

Female↗
PubMed2004

Training guided by pain threshold speed. Effects of a home-based program on claudication.

AIM: To verify the effectiveness of a 120 day home-based program guided by the pain threshold speed (PTS). METHODS: Twenty-nine patients with stable claudication were measured for ankle pressure (AP), ankle-brachial index (ABI), PTS, maximal speed (Smax) on treadmill. Daily walking sessions at a speed 20-30% below PTS were prescribed. Determination of the training speed was supervised and facilitated at home. The program included a daily record of exercise data and symptoms, an intermediate PTS re-evaluation to adjust the training speed, and the reassessment of all the parameters after 120 days. RESULTS: Overall patients showed a reduction of systemic blood pressure (151.3+/-14.3 to 147.6+/-18.3 mmHg; 77.1 +/-9.1 to 72.4+/-8, p=0.008) while AP did not. ABI increased from 0.65+/-0.13 to 0.71+/- 0.18 (p=0.01). PTS and Smax rose from 3.2+/-1.1 to 4.2+/-1.5 km/h (p=0.0001) and from 3.9+/-1.3 to 4.6+/-1.3 km/h (p=0.0001), respectively. According to their compliance, patients were divided into 3 groups: 1) trained (T, n=14): exercise at the prescribed speed, 2) free-walkers (FW, n=7): walking speed markedly below PTS and 3) untrained (U, n=8): incomplete program compliance. T group showed symptom reduction up to pain disappearance. The ABI change (0.72+/-0.09 to 0.82+/- 0.16, p<0.02) was correlated to AP increase (r= 0.879). PTS and Smax rose from 3.6+/-1.1 to 5.4+/-0.8 km/h (p<0.02) and from 4.7+/-1.2 to 5.7+/-0.7 (p<0.02), respectively. FW showed improvement of all parameters, and U a better walking efficiency. CONCLUSIONS: In patients with claudication, a low-cost home-based program driven by PTS allows dramatic improvements of functional parameters.

Aged↗
PubMed2003

Minimally invasive surgical management of primary venous ulcers vs. compression treatment: a randomized clinical trial.

OBJECTIVES: to compare minimally invasive surgical haemodynamic correction of reflux (CHIVA) with compression in the treatment of venous ulceration. DESIGN: prospective randomised study. MATERIALS AND METHODS: from a cohort of 80 patients with 87 venous leg ulcers, 47 were randomised to either surgery or compression. RESULTS: at a mean follow-up of 3 years, healing was 100% (31 days) in the surgical and 96% (63 days), in the compression group (p<0.02). The recurrence rate was 9% in the surgical and 38% in the compression group (p<0.05). In the surgical group, all plethysmographic parameters except ejection fraction, had improved significantly at 6 months in the surgical group, and at 3 years residual volume fraction remained in the normal range. Finally, quality of life significantly improved in the operated group. CONCLUSIONS: this study supports the effectiveness of surgical therapy for leg ulceration secondary to superficial venous reflux.

Aged↗
PubMed2001

Comparison of prazosin, terazosin and tamsulosin: functional and binding studies in isolated prostatic and vascular human tissues.

BACKGROUND: Terazosin and tamsulosin are drugs currently used in the treatment of benign prostatic hypertrophy (BPH). The potency of these two alpha(1) receptor antagonists and that of prazosin to inhibit contractions induced by noradrenaline and the binding of [(3)H]-prazosin in human prostate and four different human arterial and venous vessels (saphenous and umbilical veins, renal and mesenteric arteries) was studied. METHODS: By bioassay and binding studies, we examined the receptor affinities of different alpha(1) receptor antagonists in different human tissues. RESULTS: pKb of terazosin, tamsulosin, and prazosin obtained in the prostatic tissues (8.15, 9.64, and 8.59, respectively) were not different from those obtained in the umbilical veins (8.07, 9.56, and 8.30, respectively), in the mesenteric artery (8.27, 10.29, and 9.01, respectively), renal artery (8.35, 10.13, and 8.76, respectively) and saphenous vein (7.8, 10.3, and 9.32, respectively). IC(50) (nM) of prazosin, terazosin, and tamsulosin obtained from binding studies in membrane preparations from prostate tissue were similar to those from umbilical veins, saphenous vein, and renal artery. CONCLUSIONS: All of the evaluated drugs showed similar selectivity for prostatic vs. vascular tissues. Thus, different clinical profiles of the present drugs should not result from their differential affinity for prostatic versus vascular alpha(1)-adrenoceptors.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed2001

Reflux elimination without any ablation or disconnection of the saphenous vein. A haemodynamic model for venous surgery.

OBJECTIVES: to investigate the possibility of the haemodynamic suppression of reflux in the greater saphenous vein (GSV) without any high ligation and/or stripping procedure. DESIGN: prospective study; single group of patients. MATERIALS: forty patients affected by primary chronic venous insufficiency of all clinical classes, with demonstrated duplex incompetence both of the sapheno-femoral junction (SFJ) and the GSV trunk, with the re-entry perforator located on a GSV tributary. The re-entry point was defined as the perforator, whose finger compression of the superficial vein above its opening eliminates reflux in the GSV. METHODS: air-plethysmographic parameters as well as duplex scanning were performed both preoperatively, and 1 and 6 months later, respectively. Operation consisted in flush ligation and division from the GSV of the tributary containing the re-entry perforating vein. RESULTS: duplex investigation demonstrated both a forward flow and reflux disappearance in the GSV in 100% and 85% of the cases after 1 and 6 months, respectively. All air-plethysmographic parameters, with the exception of Ejection Fraction, improved significantly: Venous Volume changed from 150+/-9 ml to 114+/-7 ml (p <0.0001), Venous Filling Index from 4.9+/-0.5 ml/s to 2.3+/-0.2 ml/s ( p <0.0001), and Residual Volume Fraction from 42+/-3 ml to 30+/-2 ml ( p <0.0001). CONCLUSIONS: this study demonstrates that reflux in the GSV system is supported by a gradient of pressure between the anatomical point of reflux and the point of re-entry in the deep veins. Disconnection of the flow to the re-entry perforator without high ligation of the sapheno-femoral junction suppresses GSV reflux.

Analysis of Variance↗
PubMed2001

Laparoscopic approach for esophageal achalasia with epiphrenic diverticulum.

We report the case of a 65-year-old woman with a 10-year history of dysphagia, regurgitation, cough, and 10-kg weight loss caused by an epiphrenic diverticulum associated with esophageal achalasia managed with a laparoscopic approach. A preoperative barium swallow showed a dilated sigmoid esophagus with a 6-cm epiphrenic diverticulum. Esophageal manometry confirmed the absence of peristalsis in the esophageal body. We performed a laparoscopic diverticulectomy and a 7-cm distal esophageal myotomy with a Dor fundoplication. The postoperative course was uneventful. On the third postoperative day a barium swallow showed no leak, and the patient started oral intake. She was discharged home 5 days after the operation free of symptoms and tolerating a soft diet. Sixteen months after surgery, she was asymptomatic and had gained 8 kg. A barium swallow showed a normal-size esophagus with regular emptying. We reaffirm the feasibility, safety, and efficacy of the laparoscopic diverticulectomy and distal myotomy with Dor fundoplication to manage epiphrenic diverticula resulting from esophageal achalasia.

Aged↗
PubMed2000

Identification of a CD11b(+)/Gr-1(+)/CD31(+) myeloid progenitor capable of activating or suppressing CD8(+) T cells.

Apoptotic death of CD8(+) T cells can be induced by a population of inhibitory myeloid cells that are double positive for the CD11b and Gr-1 markers. These cells are responsible for the immunosuppression observed in pathologies as dissimilar as tumor growth and overwhelming infections, or after immunization with viruses. The appearance of a CD11b(+)/Gr-1(+) population of inhibitory macrophages (iMacs) could be attributed to high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in vivo. Deletion of iMacs in vitro or in vivo reversed the depression of CD8(+) T-cell function. We isolated iMacs from the spleens of immunocompromised mice and found that these cells were positive for CD31, ER-MP20 (Ly-6C), and ER-MP58, markers characteristic of granulocyte/monocyte precursors. Importantly, although iMacs retained their inhibitory properties when cultured in vitro in standard medium, suppressive functions could be modulated by cytokine exposure. Whereas culture with the cytokine interleukin 4 (IL-4) increased iMac inhibitory activity, these cells could be differentiated into a nonadherent population of fully mature and highly activated dendritic cells when cultured in the presence of IL-4 and GM-CSF. A common CD31(+)/CD11b(+)/Gr-1(+) progenitor can thus give rise to cells capable of either activating or inhibiting the function of CD8(+) T lymphocytes, depending on the cytokine milieu that prevails during antigen-presenting cell maturation. (Blood. 2000;96:3838-3846)

Animals↗
PubMed2000

Genetic vaccination with "self" tyrosinase-related protein 2 causes melanoma eradication but not vitiligo.

"Self" melanocyte differentiation antigens are potential targets for specific melanoma immunotherapy. Vaccination against murine tyrosinase-related protein (TRP)-1/gp75 was shown recently to cause melanoma rejection, which was accompanied by autoimmune skin depigmentation (vitiligo). To further explore the linkage between immunotherapy and autoimmunity, we studied the response to vaccination with a related antigen, TRP-2. i.m. inoculation of plasmid DNA encoding murine trp-2 elicited antigen-specific CTLs that recognized the B16 mouse melanoma and protected the mice from challenge with tumor cells. Furthermore, mice bearing established s.c. B16 melanomas rejected the tumor upon vaccination with a recombinant vaccinia virus encoding trp-2. Depletion experiments showed that CD8+ lymphocytes and natural killer cells were crucial for the antitumor activity of the trp-2-encoding vaccines. Mice that rejected the tumor did not develop generalized vitiligo, indicating that protective immunity can be achieved in the absence of widespread autoimmune aggression.

Animals↗