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Biomedical subjects

G Ricci

Publications and source records attributed to G Ricci.

At least 163 records · Page 9Linked to original sources
PubMed1995

Intramuscular ganglia arising from the superior tibiofibular joint: CT and MR evaluation.

OBJECTIVE: To evaluate the role of magnetic resonance imaging (MRI) and computed tomography (CT) in the diagnosis of intramuscular ganglia (IMG) that arise from the superior tibiofibular joint (STFJ). MATERIAL AND METHODS: Our series consisted of three men and three women. Four patients were studied by MRI, one by CT only, and two by both modalities. Contrast was used in one of the two patients studied by CT. MRI was obtained in at least two orthogonal planes to demonstrate the relation of the ganglia to STFJ. RESULTS: The MR and CT appearance of these ganglia was basically that of a well-defined soft tissue mass with low attenuation on CT images consistent with the presence of fluid. On MR studies, they had an isointense signal on T1-weighted images and a homogenous high-intensity signal on T2-weighted images. MRI demonstrated the attachment of these ganglia to the STFJ. CONCLUSION: CT and MRI were effective, noninvasive modalities in the evaluation of IMG. The imaging features on both modalities were consistent with the presence of fluid- containing lesions that had close proximity and were attached to the STFJ. The combination of location and the fluid consistency of these lesions facilitated the diagnosis.

Adult↗
PubMed1995

Comparison of serum total sialic acid, C-reactive protein, alpha 1-acid glycoprotein and beta 2-microglobulin in patients with non-malignant bowel diseases.

Total sialic acid (TSA), C-reactive protein (CRP); alpha 1 acid glycoprotein (alpha 1-AG), and beta 2-microglobulin were determined in 84 patients affected by non-malignant intestinal diseases, Crohn's disease (CD) and ulcerative colitis (UC), active and in remission; non-ulcerative proctosigmoiditis; diverticulosis; diverticulitis (ie, inflammatory complication of diverticulosis). Only in patients with acute phase CD, TSA was statistically higher than those in remission, as well as in controls. In patients with acute CD and in those with diverticulitis, CRP was significantly higher than in the controls. alpha 1-AG was found significantly increased in acute UC and CD patients versus the respective groups in remission, as well as versus controls. Moreover, alpha 1-AG was higher in patients with diverticulitis. beta 2-microglobulin did not differ in any group of patients. In five patients with CD in acute phase, investigated before and during the pharmacological treatment (5-aminosalycilic acid and steroids), CRP values fell into the normal range after the second week of therapy, whereas TSA values reached the higher limit of the normal range after the third week, except for two CD patients with a larger location (ileocolonic) of the disease. The results are briefly discussed.

Adolescent↗
PubMed1995

Study of functionality of cochlear outer hair cells in patients with retinitis pigmentosa.

Hearing functionality was studied in 30 patients affected by retinitis pigmentosa (RP) and 25 of their relatives. These patients were defined as normal-hearing on the basis of pure-tone threshold audiometric and acoustic immittance tests. The evoked otoacoustic emissions (EOEs) were studied in these normal hearing patients. EOEs are an extremely sensitive method to study the functionality of the outer hair cells of the organ of Corti. In RP patients and in their relatives the values of EOE (amplitude, intensity and frequency) were found to be statistically reduced compared to those of control subjects. The EOEs turned out to be clearly pathological in 60% of patients with RP and in 24% of their relatives. During the embryologic development there is one transitory axoneme in the outer hair cells of the organ of Corti. This axoneme is important for the organization of the stereocilia. The axonemes are found inside a few mature hair cells, including the photoreceptors. The alteration of cochlear outer hair cells in a high percentage of patients with RP and in some of their relatives seems to corroborate the hypothesis that, in many cases, retinitis pigmentosa may be due to a structural anomaly of the ciliated cells.

Adolescent↗
PubMed1995

HIV-specific lymphoproliferative responses in asymptomatic HIV-infected individuals.

In vitro lymphoproliferative responses to HIV-1 recombinant antigens (gp160, p24, and Rev protein) were studied in 83 patients with asymptomatic HIV-1 infection (CDC groups II and III) and circulating CD4 lymphocyte numbers > 400/mm3. Significant response to at least one of the three antigens was detected in 52.4% of the subjects, but the responses were weak, and concordance of the response to the three antigens was rare, the frequency of individuals responding to each antigen not exceeding 22.4%. Increasing frequencies of response were observed when recall antigens (tetanus toxoid and Candida albicans glycomannoprotein) (65.5%) and anti-CD3 MoAb (76.6%) were used as stimuli. Although a significant association between lymphocyte response to p24, but not gp160, and steadiness of CD4 lymphocyte numbers before the assay was observed, no predictive value for lack of CD4 cell decrease was confirmed for either antigen, and fluctuation of the responses to HIV antigens was seen during subsequent follow up. The panel of T cell assays used could be regarded as appropriate for monitoring both HIV-specific responses and T lymphocyte function during immunotherapy with soluble HIV antigens.

Adolescent↗
PubMed1995

Evaluation of functionality of cochlear outer hair cells in patients with retinitis pigmentosa and in their relatives.

Hearing functionality was studied in 36 patients with retinitis pigmentosa (R P) and 29 of their relatives. These patients were defined as having bilateral normal hearing on the basis of tonal-threshold audiometric and acoustic-immittance tests. The transiently evoked otoacoustic emissions (T E O A Es) were studied in these normal hearing patients. T E O A Es represent an extremely sensitive method to study the functionality of the outer hair cells of the organ of Corti. When the values of T E O A E amplitude, intensity, and frequency in R P patients and in their relatives were compared with those in control subjects, they were found to be significantly reduced. The T E O A Es were clearly pathological in 52.8% of patients with R P and in 24.1% of their relatives. During embryologic development, there is one transitory axoneme in the outer hair cells of the organ of Corti; this transitory axoneme is important for the organization of the stereocilia. Axonemes are found in mature hair cells, including photoreceptors. The alteration of cochlear outer hair cells in a high percentage of patients with R P and in some of their relatives corroborates the hypothesis that, in some instances, retinitis pigmentosa may be due to a structural anomaly of the ciliated cells.

Adolescent↗
PubMed1995

Sonographic evaluation of lipohemarthrosis: clinical and in vitro study.

The purpose of this study is to evaluate the role of sonography in diagnosing lipohemarthrosis. Sonography was performed on seven patients with intra-articular fractures of the knee, shoulder, and hip. An in vitro mixture of fat and blood was examined as the gold standard. In the patients scanned a few minutes after immobilization, a two-band appearance of joint effusion was present, representing a fat-blood level. One patient scanned 3 hours after immobilization showed a three-band appearance of joint effusion, corresponding to the layers of fat, serum and red blood cells. Results of this study indicate a high reliability of ultrasonography in detecting lipohemarthrosis.

Adipose Tissue↗
PubMed1995

Sonographic examination of muscle herniation.

Muscle herniation is defined as a protrusion of a portion of a muscle through a defect of the muscle fascia. Although muscle herniation usually is only a cosmetic problem, the condition can lead to spontaneous pain, cramp, or local tenderness. We report eight patients in whom sonographic examination was used to diagnose a muscle herniation. The sonographic technique demonstrates the muscle bulging and the fascial defect. Dynamic examination permits the demonstration of reduction of the herniated muscle substance when pressure is applied through the probe. Although the diagnosis of muscle herniation can be suspected at physical examination, nevertheless sonography can be useful in confirmation.

Adipose Tissue↗
PubMed1995

Expansile subchondral degenerative bone cyst secondary to osteoarthritis.

A 53-year-old man known to have osteoarthritis of the left knee was examined because of a soft-tissue swelling overlying the pes anserinus tendon. Plain radiography and computed tomography revealed an expansile subchondral cyst of the proximal tibia. The cyst was multiloculated, had a sclerotic margin and an extraosseous soft-tissue component, and interrupted the cortex. Proof of a degenerative cyst was obtained by open biopsy. Such presentation in the knee is rare. Awareness of the possible aggressive behaviour of such degenerative cysts should help avoid confusion with neoplasm.

Bone Cysts↗
PubMed1995

[Rhinocerebral mucormycosis: a case report].

The Authors report a case history of rhinocerebral mucormycosis in a patient with chronic lymphatic leukaemia and recommend that therapy be based on three different approaches: treatment for the underlying disease, systematic antifungal treatment with Amphotericine B, and surgical asportation of diseased tissue. They affirm that results may be surprisingly successful, even in cases with signs of orbital-cerebral involvement which are indicative of a poor prognosis and the concomitant presence of a serous disease such as leukaemia.

Aged↗
PubMed1995

[Otoacoustic distortion products in adults with normal hearing].

Distortion Product Otoacoustic Emissions (DPOEs) are otoacoustic emissions evoked by two pure equilevel tones (f1, f2) called primaries and are believed to provide frequency-specific information regarding cochlear function. We recorded DPOEs at 2f1-f2 frequency with a constant frequency ration (f2/f1 = 1.22) in 8 normal hearing subjects (16 ears, mean age 28 +/- 1.5) to establish the characteristics of these emissions in the adult population. DPOEs were measured at the following F2 frequencies and respective fp geometric mean frequencies: 696/632, 1001/904, 1501/1360, 2002/1809, 3003/2714, 4004/3626, 5005/4531 e 6006/5435 Hz. Detailed testing included the recording of DPOE "audiograms" and input-output functions depicting the relationship of the amplitudes of DPOE to primary-tone levels ranging from 25 to 70 dB SPL in 5 dB steps. The present findings are in good agreement with investigations based on evoked otoacoustic emissions published by other researchers. The average DPOE "audiograms" demonstrated a low-frequency maximum at 1501 Hz (f2)/1360 (fp) and a high-frequency peak at 5005 Hz (f2)/4531 (fp). The two maximum regions were separated by a minimum around 3003 Hz (f2)/2714 (fp). This study confirms the feasibility of DPOE measurements among adults and provide a normal baseline for this age group. DPOEs could be useful, in association with evoked otoacoustic emissions and with auditory brainstem responses, in obtaining a precise evaluation of the peripheral auditory system.

Acoustic Stimulation↗
PubMed1995

Surgical reinstatement of aesthetics in the maxillary anterior region: a case report.

The maxillary anterior region is frequently treated for aesthetic enhancement. This article presents the case of a patient who had undergone surgery for treatment of a tumor of the hypophysis involving intraoral access to the sella turcica. The treatment had caused the formation of severe gingival recession on the buccal surface of the maxillary anterior teeth. A variety of surgical techniques were considered for covering the exposed root surfaces. The surgical site was analyzed, and the response of the periodontal tissue to the treatment was anticipated. The bilaminar method, utilizing a subpedicle connective tissue graft (SCTG), was selected. The learning objective of this case presentation is to demonstrate that when the appropriate treatment procedure is selected, restoration of function and aesthetics can be achieved even in the most advanced cases.

Adult↗
PubMed1994

A kinetic study on pantetheinase inhibition by disulfides.

The mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Duprè, S. & Cavallini, D. (1986) Biochim. Biophys. Acta 870, 82-91]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site.

Amidohydrolases↗
PubMed1994

Are the steady state kinetics of glutathione transferase always dependent on the deprotonation of the bound glutathione? New insights in the kinetic mechanism of GST P 1-1.

Steady state kinetics measurements performed on human placenta glutathione transferase (GST P 1-1), utilizing 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) as co-substrate, show that the kcat value (approximately equal to 1.2 s-1) is pH-independent between pH 4.0 and 7.0 and is scarcely affected by the nature of the leaving group. The pH profile of kcat/KmNBD-Cl suggests a pKa > or = 6.0 for GSH bound to the enzyme. Pre-steady state experiments demonstrate the presence of a burst-phase in which the conjugation product (or the sigma-complex intermediate) accumulates in an amount stoichiometric to the GST active site concentration. These results indicate that the steady state kinetics of GST P 1-1 with NBD-Cl are independent of the deprotonation of the bound GSH between pH 4.0 and 7.0 because the rate-limiting step is the product release. The occurrence of a fast enzymatic conjugation of GSH with a number of poor substrates or even electrophilic inhibitors of GST, mainly performed in a single turnover reaction, may reveal a further detoxicating role of GST.

4-Chloro-7-nitrobenzofurazan↗
PubMed1994

Accumulation of human apolipoprotein-E in rat plasma after in vivo intramuscular injection of naked DNA.

Naked DNA was found to be incorporated and consistently expressed after in vivo direct injection into striated muscle. In addition to the local expression of muscle-related or exogenous proteins, intramuscular direct gene transfer may be a useful tool to deliver recombinant proteins into the blood stream. However, no direct demonstration of recombinant protein secretion from muscle to the circulation has been reported thus far. We have injected a naked plasmid DNA containing the human receptor-binding defective apo-E2 cDNA, under the control of CMV promoter, into the quadriceps of Yoshida rats, affected by hereditary hypercholesterolemia and altered LDL-receptor activity. Plasma accumulation of human apo-E2 was demonstrated for at least 45 days after injection. On the contrary, the expression of the normal human apo-E3, injected into the muscle of normal Wistar rats, was demonstrated only in the area of muscular injection and not in the blood plasma. Endogenous rat apo-E expression was not affected by the exogenous human apo-E2 production. Our results demonstrate the availability of intramuscular direct gene transfer as a safe and simple method for the chronic systemic delivery of recombinant proteins to the circulation, although further improvements are needed in order to enhance the efficiency and stability of expression.

Animals↗
PubMed1994

Evoked otoacoustic emissions behaviour in retinitis pigmentosa.

The hearing function was studied in 26 patients affected by retinitis pigmentosa (RP) and in their relatives. Sixteen patients showed bilateral normal hearing when examined with traditional audiometric methods. In these normoacusic patients evoked otoacoustic emissions (EOE) have been studied. The EOE offer a unique opportunity to measure objectively the function of outer hair cells: they record the amplitude of the energy produced by the outer hair cells of the coclea following an acoustic stimulation. The data have been statistically compared, using the Student's t-test, with those obtained in a homogeneous control-group of normal subjects. In normoacusic subjects with RP the average values of EOE intensity are statistically lower than those of normal subjects in 64 of the 127 frequency bands examined. Moreover, the distribution of the EOE in patients with retinitis pigmentosa proved to be more discontinous than that observed in the normal subjects. The EOE recorded in 14 normoacusic relatives show in some cases small anomalies but the data, on account of the limited sample group, cannot be statistically evaluated. Therefore a subclinical alteration of the Organ of Corti is found in 100% of the patients affected by RP, although they appear to be normoacusic to usual audiometric tests.

Acoustic Stimulation↗