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Biomedical subjects

M Giglio

Publications and source records attributed to M Giglio.

At least 19 recordsLinked to original sources

Transient oscillations in Soret-driven convection in a colloidal suspension.

We present measurements of the transient stage of Soret-driven convective instability. The sample is a diluted colloidal suspension of silica spheres in water with an unusually large negative Soret coefficient S(T). A large temperature gradient (heating from above) is rapidly applied over the sample, while a shadowgraph imaging technique provides images of the convective flow. From the processing of the variance of the intensity of the images we are able to recover the time evolution of the overall intensity of the convective flow. A typical evolution of such signal exhibits, after a latency time, a peak followed by some damped oscillations leading to a steady-state value. Both the onset time tau(p) (the temporal position of the first peak), and the oscillation period tau(osc) show a power law dependence as a function of the solutal Rayleigh number R(s). The exponents found are compared with predictions from existing models.

Journal Article↗

Heterodyne near-field scattering: a technique for complex fluids.

We implemented the heterodyne near-field scattering (HNFS) technique [Appl. Phys. Lett. 81, 4109 (2002)]], showing that it is a fairly valid alternative to traditional elastic low-angle light scattering and quite suitable for studying complex fluids such as colloidal systems. With respect to the original work, we adopted a different data reduction scheme, which allowed us to improve significantly the performance of the technique, at levels of sensitivity and accuracy much higher than those achievable with classical low-angle light scattering instrumentation. This method also relaxes the requirements on the optical/mechanical stability of the experimental setup and allows for a real time analysis. The HNFS technique has been tested by using calibrated colloidal particles and its capability of performing accurate particle sizing was ascertained on both monodisperse and bimodal particle distributions. Nonstationary samples, such as aggregating colloidal solutions, were profitably studied, and their kinetics quantitatively characterized.

Journal Article↗

Combined oral therapy with sildenafil and doxazosin for the treatment of non-organic erectile dysfunction refractory to sildenafil monotherapy.

The purpose of this work was to investigate the efficacy and safety of sildenafil in combination with doxazosin for the treatment of non-organic erectile dysfunction in patients who did not respond to sildenafil. We enrolled 28 patients with non-organic erectile dysfunction, for whom 3 months of sildenafil monotherapy had failed. They were divided in two random and homogeneous groups: 14 were treated with doxazosin (4 mg daily) and sildenafil (100 mg 1 h before sexual intercourse); the other 14 patients received sildenafil and placebo. The results were assessed by means of the IIEF questionnaire before the beginning of the study, after 30 days of therapy and after 60 days. Of the 14 patients treated with doxazosin and sildenafil, 11 (78.6%) showed a statistically significant increase of IIEF; in the placebo group, only one patient (7.1%) recorded a significant IIEF increase. The differences observed in the two groups were statistically very significant (P=0.0016). Blood pressure did not show significant alterations. Side effects were minimal and even present during sildenafil monotherapy. The combination therapy with sildenafil and doxazosin resulted in the safe and effective treatment of men with non-organic erectile dysfunction for whom sildenafil alone had failed.

Adult↗

Histological changes following two-step flap gastrocystoplasty in rats.

INTRODUCTION: A gastric segment used to increase bladder capacity can undergo considerable changes over time, as can all intestinal segments implanted in the urinary tract and in contact with urine. This experimental study reports the differences between the histological alterations observed in the gastric patch transposed in the bladder both with its own pedicle and after deafferentation from the stomach. MATERIALS AND METHODS: A group of 30 young male Sprague-Dawley rats underwent gastrocystoplasty. Survivors were divided into 3 groups: gastrocystoplasty alone (8 rats); gastrocystoplasty with vascular deafferentation at 15 days (7 rats), and at 2 months (8 rats). 5 rats were used as controls. Urinary pH was evaluated during a 6-month follow-up. RESULTS: Histology showed that early devascularization hindered the fusion of the two mucosae in the junctional area but reduced papillary hyperplasia (p = 0.013) of the gastric mucosa. No changes were observed in urinary pH after patch devascularization. CONCLUSIONS: Vascular deafferentation creates a gastric flap on the bladder which, even if it does not prevent urinary acidification, reduces the frequency of histologically detected changes susceptible for transformation into neoplasms.

Animals↗

Traumatic rupture of the corpora cavernosa: new physiopathologic acquisitions.

OBJECTIVES: To investigate the physiopathologic mechanisms of the rupture of the corpora cavernosa by means of a histologic study of the tunica albuginea. METHODS: In 6 patients (age range 28 to 49 years, mean 38) with traumatic penile rupture, samples of the tunica albuginea were taken during corrective surgery far from the site of the lesion. These specimens were analyzed with light microscopy by the same pathologist and compared with other samples of tunica albuginea taken from 7 patients who underwent penile surgery for other reasons. RESULTS: Five of the 6 patients with traumatic penile rupture had histologic anomalies of the tunica albuginea (fibrosclerosis in all 5 patients [83%] and phlogistic cellular infiltrations composed of lymphocytes or histiocytes in 3 patients [50%]). Only 1 patient (17%) with traumatic rupture of the corpus cavernosum had a completely healthy tunica albuginea. None of the control specimens revealed any histologic alterations. CONCLUSIONS: Structural anomalies could alter the mechanical properties of the tunica albuginea, representing a weakening factor of the corpora cavernosa and thus a predisposing factor for traumatic rupture of the penis. Therefore, patients with anomalous albuginea could undergo penile rupture even at intracavernous pressures inferior to pressures usually necessary to cause rupture in patients with healthy albuginea.

Adult↗

Arterial priapism and cycling: a new worrisome reality?

Arterial priapism is a rare condition caused by the traumatic formation of an arteriolacunar fistula. We report 2 cases of arterial priapism after cycling injuries. Both patients sustained a violent perineal trauma against the top tube on the bicycle. In both cases, penile detumescence was obtained by superselective arteriographic embolization of the fistula with gelatin sponge or microcoil. The fistula was monolateral in the first case and bilateral in the second. Cycling should be considered a possible risk factor for arterial priapism as it is for urethritis, prostatitis, hematuria, testicular torsion, scrotal and penile numbness, and erectile dysfunction.

Adult↗

Adult testicular pure yolk sac tumor.

Here we describe the clinical, ultrasonographic and histological features of a rare pure adult yolk sac tumor detected in the right testis of a 44-year-old male. Due to the rarity of this neoplasm (less than 10 cases have been reported), there is no unanimous consensus for therapy following inguinal orchiectomy. We believe that nerve-sparing retroperitoneal lymph node dissection could be potentially curative and useful for future interpretations of this tumor's potential evolution.

Adult↗

Scrotal extraperitoneal hernia of the ureter: case report and literature review.

Ureteral herniation is a rare, often misdiagnosed event and serious surgical complications are possible. Until 1992, 128 cases of ureteral herniation were reported and in 54 (42%) the inguino-scrotal region was involved. From an anatomical and pathogenic standpoint, two types of uretero-inguinal hernias can be identified: paraperitoneal (more frequent, acquired, always presenting a peritoneal hernia sac, frequently associated with other herniated abdominal structures) and extraperitoneal (very uncommon, congenital, never associated with a true peritoneal sac, always composed only of the ureter). We describe a new case of scrotal extraperitoneal ureteral hernia and review the current urological, surgical and radiological literature to analyze the main clinical characteristics of this pathology and its ideal treatment.

Aged↗

Patients' perceptions of medical students in a longitudinal family medicine clerkship.

BACKGROUND: Although educational characteristics of ambulatory clinical environments are becoming clearer, less is known concerning patient opinions about participating in medical student instruction in ambulatory settings. Such perceptions may have an important influence on recruitment and retention of community faculty. METHODS: Surveys were administered to 121 patients seen by medical students during a longitudinal family medicine clerkship. The survey explored patients' opinions regarding the extent of direct student involvement in their care, students'competence, and patient feelings about participating in medical student instruction. RESULTS: Patients felt that students were highly involved in providing care and that they performed competently and professionally. Patients found participation in medical education enjoyable, not excessively time-consuming or disruptive, and believed that students' participation improved the quality of care they received. CONCLUSIONS: Patients in our family medicine clerkship do not have negative perceptions about their participation in medical student education. In fact, this study suggests that such participation may actually enhance patient satisfaction.

California↗

[Endourologic treatment of benign uretero-intestinal stenosis in patients with definitive urinary diversion: 10-year experience].

OBJECTIVE: Ureterointestinal (U-I) anastomotic stricture is one of the most important complications after radical cystectomy, occurring in 4% to 8% of patients. We report our ten years experience in the endourological treatment of this condition. MATERIALS AND METHODS: 32 patients with U-I strictures were endourologically treated at our Institution. The endoscopic procedure provides for a percutaneous nephrostomy, the passage of the stenosis with a guide-wire, the incision and balloon dilation of the stricture and, finally, a ureteral double J stenting. Of the 28 successfully treated patients, 10 underwent balloon dilation alone and 18 both ureteral incision (with cold knife in 11 and hot knife in 7) and dilation. RESULTS: The endourological approach failed in 4/32 (12.5%) patients: 3 failures were due to the inability to pass a guide-wire across the stricture, whilst in the remaining patient a serious intraoperative hemorrhage occurred. In 28/32 (87.5%) patients the endoscopic treatment was successful (a ureteral stent was positioned across the stenosis). However, long term results are less promising: at 6-90 month follow up, only 16 patients (57.1%) are free of strictures without ureteral stent, 10 (35.7%) need a permanent ureteral stent, 2 (7.2%) a percutaneous nephrostomy. CONCLUSION: Due to the low morbidity of endoscopic procedures and to the high risks associated with open surgery, we believe that endourology should represent the first choice in the treatment of U-I strictures, reserving open surgery for endoscopic failures or complications. Moreover, endourological treatment with both incision and dilation is more effective than dilation alone (which should be performed only in very short and recent strictures).

Aged↗

[Evaluation of the association between benign prostatic hyperplasia and sexual disorders].

OBJECTIVE: The aim of this study was to determine the incidence of sexual dysfunction in patients with benign prostatic hyperplasia (BPH). METHODS: During the last 6 months 88 patients (mean age 65 years, range 55-78) suffering from BPH, without other chronic disease, were studied. RESULTS: Andrological evaluation enabled us to find erectile dysfunction in 52% of patients, ejaculation problems in 41% and decrease of libido in 54%. CONCLUSION: Due to the great impact of these disturbances in patients' quality of life, we believe that clinical and therapeutic approach in BPH patients should be global, with both urological and andrological assessment.

Aged↗

Space intensity correlations in the near field of the scattered light: A direct measurement of the density correlation function g(r)

We show that the two point intensity correlation in the near field of the scattered light is directly related to the two point density correlation g(r). Preliminary measurements on two sets of calibrated random pinholes of 140 and 300 &mgr;m diameters, and on aqueous solutions of latex spheres of 5, 10, and 40 &mgr;m are reported. A discussion on the desirability of the technique as a simple and powerful alternative to low angle scattering will be presented.

Journal Article↗

Assessing the acquisition of core clinical skills through the use of serial standardized patient assessments.

PURPOSE: Students in many medical schools now undergo multiple standardized-patient-based assessments. In this study, the authors examine the ability of such serial assessments to detect interval learning. METHOD: Twenty-one students from the University of California, Irvine, College of Medicine, class of 1999, underwent a clinical skills appraisal after three months of their third-year instruction. After nine months, all 89 members of that class completed an OSCE. Subsequently, all 87 students in the class of 2000 also completed clinical skills assessments after their third and ninth months of third-year instruction. All of these exercises included identical or similar stations measuring history, physical examination, and communication skills. Communication skills were measured somewhat differently during some of the exercises, using checklists that were either "content-" or "process-"oriented. The authors compared the performances for all groups. RESULTS: Both classes demonstrated significant improvement in physical examination performance, while their history performances remained unchanged. According to the assessments, their communication skills deteriorated over the course of their third-year instruction. Repeated exposures to similar or identical cases on the serial assessments did not impact the students' performances. Both content- and process-oriented measures of communication skills yielded highly similar results. CONCLUSIONS: Serial assessments using standardized patients can detect interval changes in performance that are independent of repeated exposures to similar or identical cases. Changes detected using this approach may have important curricular implications.

Clinical Competence↗

Universal behavior of nonequilibrium fluctuations in free diffusion processes

We show that giant nonequilibrium fluctuations are present during the free diffusive remixing occurring in ordinary liquid mixtures and in macromolecular solutions. The static structure factor of the fluctuations is measured by using a quantitative shadowgraph technique. We show that structure factors at different times and from different samples can be rescaled onto a single master curve without any adjustable parameter, thus giving strong evidence that nonequilibrium fluctuations are a universal feature of free diffusion processes.

Journal Article↗

Equilibrium and nonequilibrium fluctuations at the interface between two fluid phases

We have performed small-angle light-scattering measurements of the static structure factor of a critical binary mixture undergoing diffusive partial remixing. An uncommon scattering geometry integrates the structure factor over the sample thickness, allowing different regions of the concentration profile to be probed simultaneously. Our experiment shows the existence of interface capillary waves throughout the macroscopic evolution to an equilibrium interface, and allows us to derive the time evolution of surface tension. Interfacial properties are shown to attain their equilibrium values quickly compared to the system's macroscopic equilibration time.

Journal Article↗

[Experimental microsurgical gastrocystoplasty] .

BACKGROUND: Stomach tract used for bladder augmentation decreases urinary pH and produces the syndrome of dysuria and hematuria; gastric mucosa in contact with urine may develop prominent histopathological changes including proliferative lesions. The aim of this study was to investigate in an experimental model the possibility of detecting the factors involved in the mucosal damage. METHODS: Thirty-five Sprague Dawley rats randomly underwent microsurgical gastrocystoplasty or sham operation (5 controls). During operation elliptical gastric patch was isolated with its gastroepiploic vascular pedicle, bladder was opened with midline incision and anastomosis performed. Urine was aspirated from the bladder for culture, pH and electrolytes evaluation; venous blood was samples for electrolytes, BUN and creatinine. Mean follow-up time was 6 months. RESULTS: Of the 30 rats subjected to gastrocystoplasty 23 survived (77%). All of cultures were negative, the urinary pH decreased after operation and increased gradually two months later. Urinary sodium and potassium ions concentrations increased significantly in gastrocystoplasty (p < 0.05). There were no significant changes in serum electrolytes or renal function. CONCLUSIONS: This experimental model was useful to investigate the effects related to the presence of gastric mucosa in the urinary tract.

Animals↗

[Functional heart murmur and echocardiography: a solved problem?].

BACKGROUND: Is it really vanished the need for echocardiography in the differential diagnosis of functional pediatric murmurs? METHODS: To this aim 260 children (132 males, 128 females; age range 1-84 months) were examined with auscultatory cardiac murmur. All children underwent a clinical and instrumental evaluation (ECG and echocardiography) from two pediatric cardiologists with independent assessment. RESULTS: Two hundred and ten patients (Group A) were evaluated clinically with functional murmur, 45 patients (Group B) with pathological murmur, 5 patients (Group C) with uncertain pathology. ECG showed changes in 1 Group B patient. Echocardiography showed pathology in 15 Group A patients (6 patients with patent foramen ovale, 5 patients with interatrial defect, 2 patients with bicuspid aortic valve, 1 patient with mitral insufficiency, 1 patient with restrictive cardiomyopathy). Pathology was excluded in 3 Group B patients, and in 2 Group C patients. In our clinical analysis echocardiography showed sensitivity 75%, specificity 97%, positive predictive value 90%, and negative predictive value 92%. CONCLUSIONS: In our experience we suggest to perform echocardiographic examination in children with functional murmur for complete assessment.

Child↗