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Biomedical subjects

F Micali

Publications and source records attributed to F Micali.

At least 19 recordsLinked to original sources
PubMed1998

Correlation between biochemical composition and magnetic resonance appearance of articular cartilage.

OBJECTIVE: The objective of this study was to find a correlation between magnetic resonance (MR) appearance and biochemical composition of the normal articular cartilage by comparing the laminar aspects with the distribution of the two principal matrix components: proteoglycans and collagen. DESIGN: T2-weighted MR microimages of porcine cartilage-bone plugs, excised from both the habitually loaded and habitually unloaded regions of the proximal end of the humerus, were obtained using a spin-echo sequence. Proteoglycans (PGs) were monitored by histology and by measuring the uronate and the sulfur content of the tissue; a histologic method and the chemical determination of hydroxyproline were used for the evaluation of the collagen content. RESULTS: The 'loaded' cartilage exhibited the expected MR laminar appearance whereas the 'unloaded' tissue appeared to be more homogeneous. The PG content in the 'loaded' cartilage, was found to be 2.4 times higher than in the habitually unloaded tissue, exhibiting an increasing trend from the articular surface to the bone. In the 'unloaded' cartilage the uronate distribution was more uniform with a higher concentration in the intermediate zone. The mean collagen content of both cartilage regions was found to be about 39% of the tissue dry weight. Histology and hydroxyproline distribution pattern showed that collagen was particularly concentrated at the surface and in a central zone of the 'loaded' cartilage whereas in the 'unloaded' tissue collagen was evident only at the surface. In accordance with the collagen distribution, transverse relaxation (T2) times in 'loaded' cartilage showed a minimum value at the articular surface and another minimum in a central region. On the contrary, the average T2 value of the 'unloaded' tissue was high at the surface and decreased rapidly in the deeper zones. CONCLUSION: These results demonstrate that the MR appearance of articular cartilage correlates with the collagen content, but not with that of PGs, of the different zones. Other matrix components might, however, influence the MR appearance by contributing to the macromolecular organization of the tissue.

Animals↗
PubMed1998

Antioxidant systems in rat epididymal spermatozoa.

Mammalian caput and cauda epididymidal spermatozoa exhibit diverse stages of maturation, and their plasma membrane shows diverse composition and stability levels, thus enabling these spermatozoa to undergo the acrosomal reaction after transit through the epididymis. As a result, the study of antiperoxidative mechanisms is quite relevant, since epididymal spermatozoa must be properly protected against agents such as reactive oxygen species, which can impair the complex maturation process. We considered activities of certain enzymes (glutathione peroxidase [GPx], phospholipid hydroperoxide glutathione peroxidase [PHGPx], glutathione reductase [GR], superoxide dismutase [SOD], and catalase [CAT]) and the vitamin E content in isolated rat caput and cauda epididymidal spermatozoa. The results indicate that caput epididymidal sperm have significantly greater PHGPx (3.5x), GPx (2.4x), and SOD (1.7x) activities, as well as a greater amount of vitamin E (3.8x). There were no detectable differences in the GR and CAT activities of caput and cauda epididymidal spermatozoa. The substantial drop in PHGPx activity during epididymal transit is discussed in relation to an additional function of this enzyme: the use of caput sperm protamines as a sulfhydryl substrate. In vitro peroxidation of the two sperm populations by the free radical generator (azo-initiator) 2,2'-azobis(2-amidinopropane) dihydrochloride revealed that only about 13% of the vitamin E content of the caput epididymidal spermatozoa was consumed, which contrasts with the greater consumption (about 70%) of the vitamin in cauda epididymidal spermatozoa. Selective inhibition of PHGPx, SOD, or CAT did not change this picture. The higher susceptibility of cauda epididymidal spermatozoa to radicals is discussed in relation to the diverse enzymatic activities, vitamin E content, and peroxidative response. These factors are correlated with the different stages of sperm cell maturation, which are characterized-from caput to cauda epididymidis-by progressive destabilization of the plasma and acrosomal membranes.

Animals↗
PubMed1998

[Laparoscopic surgery in day surgery].

Since ten years laparoscopic techniques have been employed as alternatives of many established open procedures in gynecologic, abdominal and finally urologic surgery. Laparoscopic techniques show significant advantages compared to open surgery, such as less hospitalization, reduced need of analgesic drugs, quick return to daily activities and far a better cosmetic results. Laparoscopic surgery has been advocated for urologic, uro-gynecologic and andrologic diseases. Since 1983 one-day surgery was proposed for only a few gynecologic and abdominal procedures and only recently for laparoscopic renal biopsy and abdominal testis evaluation. In these preliminary experiences the conditions for a correct management of laparoscopic one-day surgery have been clearly pointed out: 1. correct surgical indication; 2. through knowledge of surgical technique; 3. duration of the procedure less than 90 minutes; 4. correct anesthesia. Technique of anesthesia must be adapted to the surgical procedure required, its duration and the physical features of the patient. General anesthesia is usually preferred for either longer and more complex procedures or when a higher abdominal insufflation pressure is needed. Spinal or local anesthesia are preferred for simpler procedures or when only one trocar is required. At date only few urologic procedures seem to be suitable to one-day laparoscopic surgery. 1) Varicocele: although laparoscopic varicocelectomy in one-day surgery has never been reported previously, it can be performed in a short time, only 3 trocars are needed and insufflation pressure can be maintained within 15 mm Hg. 2) Renal biopsy and marsupialization of renal cysts. These are usually managed percutaneously but in some particular indications procedures under direct vision should be preferable. Both are short-lasting and only superficial general anesthesia is required; as surgical access is retroperitoneal only two trocars are sufficient; at date only renal biopsies have previously been reported. 3) Diagnostic procedures on abdominal testis. The procedure is brief only superficial general anesthesia is needed and only one trocar is required. Conclusions. One-day laparoscopic surgery will require in the future a more and more strict cooperation between urologists and anesthetists in order to tailor the correct anesthesiological and laparoscopic technique to the procedure required and the features of the patient.

Ambulatory Surgical Procedures↗
PubMed1997

Electromotive delivery of mitomycin C into human bladder wall.

The aim of this investigation was to establish an appropriate tissue pharmacokinetic model to compare concentrations of mitomycin C (MMC) in the human bladder wall after either passive delivery or electromotive administration (EMDA) and to evaluate the effects of EMDA on tissue morphology and MMC structure. Tissue sections of human bladder were inserted into two chamber cells with urothelium exposed to donor compartments containing MMC (10 mg in 100 ml of 0.24% NaCl solution) and an anode and with serosa exposed to receptor compartments containing 100 ml of 0.9% NaCl solution and a cathode. Fourteen paired experiments ("current 5 mA/no current") were conducted over 15 min; MMC tissue content was assessed by high-pressure liquid chromatography. Tissue viability and morphology and MMC stability were assessed by trypan blue exclusion test, tissue pH, histological analysis, and mass spectrometry analysis. MMC concentrations were increased, and variability in drug delivery rate was reduced in all tissue in samples exposed to electric current. Tissues were viable and undamaged histologically, and no MMC structural modification was observed. In conclusion, EMDA enhances administration of MMC into viable bladder wall tissue and reduces the variability in drug delivery rates.

Administration, Intravesical↗
PubMed1997

Distribution and possible novel role of phospholipid hydroperoxide glutathione peroxidase in rat epididymal spermatozoa.

The selenoenzyme phospholipid hydroperoxide glutathione peroxidase (PHGPx, EC 1.11.1.12) is present, in both free and membrane-bound form, in several mammalian tissues. It utilizes thiols such as glutathione to specifically scavenge phospholipid hydroperoxides. The testis exhibits the highest PHGPx-specific activity so far measured, and interest in the presence and function of the enzyme in this tissue has recently grown. Here we report the localization of PHGPx in rat epididymal spermatozoa and its distribution in subfractions obtained by sucrose density gradient centrifugation. Immunochemical evidence and enzymatic activity revealed for the first time that PHGPx is present in sperm heads and tail midpiece mitochondria. The binding of the enzyme to spermatozoa, head, and mitochondria was barely affected by ionic strength or thiols or detergents, as compared to the detachment of PHGPx obtained from testis nuclei. Moreover, we demonstrated that pure PHGPx exhibits a higher thiol-oxidase activity toward isolated epididymal caput protamines than toward protamines from epididymal cauda. These results suggest a role for the enzyme in the maturation of spermatozoa through the metabolism of hydroperoxides and sperm thiol oxidation, in addition to its serving as an antioxidant protector.

Animals↗
PubMed1997

Electromotive administration of oxybutynin into the human bladder wall.

PURPOSE: To compare concentrations of oxybutynin in the human bladder wall after either passive delivery (PD) or electromotive administration (EMDA). MATERIALS AND METHODS: Tissue sections of human bladder were inserted into a diffusion cell with urothelium exposed to the donor compartment containing oxybutynin (4.5 mg. in 100 ml. NaCl 0.45%) and an anode. Twelve paired experiments, "current 5 mA/no current", were conducted over 15 minutes. Oxybutynin tissue contents were measured and tissue viability, morphology and oxybutynin stability were assessed. RESULTS: Mean oxybutynin tissue concentrations were 3.84 micrograms./gm. in samples exposed to EMDA and 0.87 microgram./gm. in samples exposed to PD (p = 0.0006). The mean coefficients of variation were 57.85% in EMDA experiments and 89.78% in PD experiments. Tissues were viable and undamaged histologically and no oxybutynin structural modification was observed. CONCLUSIONS: EMDA enhances oxybutynin administration into viable bladder wall and reduces the variability in drug delivery rate.

Cholinergic Antagonists↗
PubMed1997

Benign schwannoma surrounding and obstructing the ureteropelvic junction. First case report.

With a varied presentation and a difficult preoperative diagnosis, schwannoma accounts for only a small percentage of retroperitoneal tumors. Moreover, malignant schwannoma of the adrenal gland, kidney and renal pelvis has previously been described. We report the first case of benign schwannoma causing obstruction by external compression of the ureteropelvic junction. A case report of a male patient who complained of a 3-month history of dull lumbar pain on the right side is reported. Using intravenous pyelogram, sonography and computed tomography a benign tumor of the retroperitoneum was suspected. Upon exploration, the suspected diagnosis of the tumor's retroperitoneal origin was confirmed. After the histological and immunohistochemical studies the diagnosis was verified. The diagnosis, treatment and histological features of benign schwannoma are discussed. A brief review of the literature is also included.

Humans↗
PubMed1996

Autologous adrenal medullary transplant in Parkinson's disease: critical review of our results in 13 patients.

Autotransplantation of the adrenal medullary to the caudate nucleus has been proposed for severe Parkinson's disease (PD). We describe our experience in 13 patients using a transperitoneal approach to the medullary and craniotomy for the implant: the neurosurgical equipe's decision to opt for craniotomy made quick removal of the medullary with minimal morbidity more difficult. The surgical technique are discussed. We evaluated also the impact of the procedure on urinary symptoms and sexual disturbances associated with PD. Results were disappointing. Four patients died post-operatively. The neurological pattern improved in three men and one woman. No significant improvement was observed in the urological and sexual dysfunctions.

Adrenal Medulla↗
PubMed1996

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) in rat testis nuclei is bound to chromatin.

In rat testis nuclei the activity of the selenoenzyme phospholipid hydroperoxide glutathione peroxidase (PHGPx, EC 1.11.1.12) is much higher than in other tissues and subcellular compartments, with the sole exception of mitochondria. In nuclei, the bound enzyme is solubilized by DNase I treatment, thus suggesting a binding to chromatin. Treatment with ionic strength releases about 70% of bound PHGPx, suggesting that electrostatic bonds are involved. Immunogold electron microscopy indicates the association of PHGPx with chromatin structures in isolated nuclei. A possible interpretation of these data is a PHGPx protective role against DNA peroxidative damage. Furthermore, in agreement with kinetic and structural information, PHGPx-chromatin binding could suggest an hypothetical thiol oxidase activity toward specific thiol bearing proteins which could substitute for GSH as alternative donor substrates. Such activity could give to the enzyme a new important function which is not only protective but also has a specific regulatory function in chromatin condensation.

Animals↗
PubMed1996

Endoscopic ballistic lithotripsy in the treatment of bladder calculi in patients with neurogenic voiding dysfunction.

Bladder stones represent a troublesome complication in patients suffering from neurogenic voiding dysfunction, in whom prompt and effective therapy is required. A variety of endoscopic lithotripsy methods are available; however, current devices can be tedious to use. We have treated 17 patients affected by bladder calculi and spinal cord injury or multiple sclerosis by means of the ballistic lithotripter EMS Swiss Lithoclast. The mean diameter of the stones was 2.7 cm. The mean operative time was 27 minutes. There were five intraoperative complications, including crises of autonomic dysreflexia (three patients) and light hematuria (two patients). There was no malfunction of the lithotripter and no long-term complications. All the patients were stone free at 6 months postoperatively. In conclusion, endoscopic lithotripsy with the ballistic lithotripter proved to be a very effective, rapid, and safe method for treating bladder calculi in patients with neurogenic bladders.

Adult↗
PubMed1993

Intralesional alpha interferon therapy in papillary superficial transitional cell carcinoma of the bladder. A pilot study.

The tolerability, toxicity and therapeutic efficacy of recombinant interferon alpha-2a (rIFN alpha-2a), administered by intralesional injection, were evaluated in 15 patients with papillary superficial transitional cell carcinoma of the bladder, rIFN alpha-2a was delivered endoscopically in a single weekly dose of 3 x 10(6) IU for 4 weeks (total 12 x 10(6) IU). Transurethral resection of residual tumours was then performed. The response to treatment was assessed according to ultrasonographic, endoscopic and pathological findings. One patient achieved complete remission, 6 partial remission, 6 minor remission and 2 stabilisation of disease. All patients completed the course of treatment. A mild, transient, flu-like syndrome was documented after every injection. Immunological findings suggest that the antitumour effects of rIFN alpha 2a are not mediated through the immune system.

Aged↗
PubMed1991

[Color Doppler in the diagnosis of malignant prostatic neoplasia. Preliminary results].

In the field ultrasonic diagnosis the application of color code to the duplex Doppler signal is without doubt the most up-to-date method. The common knowledge according to which all heteroplastic structures need a large quantity of O2 and provoke the formation of new vessels with the angiogenesis factor, with particularly rapid, and tumultuous fluxes due to the presence of shunt, is the basis for the use of color doppler in research on neoplasia in the initial phase. The authors submitted 11 patients considered at risk, to an echocolor Doppler study of the prostate, with a transrectal biplane probe of MHz. The exclusive application of ultrasonography grey scale, permitted the diagnosis of malignant neoplasia in 5 of these subjects. The following "color" exploration led to a cancer diagnosis in 10 patients. A bioptic check carried out through transperineal way color guided allowed the diagnosis of 8 'adenocarcinomas' and 1 undifferentiated CA.

Adenocarcinoma↗