Search PubMed⌕ Search

Biomedical subjects

S Gagliardi

Publications and source records attributed to S Gagliardi.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Computerized tomography false positives in knee medial meniscus injuries. Retrospective study of 400 cases].

PURPOSE: We retrospectively evaluated the diagnostic reliability of high resolution CT (HRCT) in the study of knee joint conditions. MATERIAL AND METHODS: We reviewed the results of 400 HRCT examinations of the knee performed in 1993 and compared them with arthroscopic findings. The patients were affected with knee pain and the physical findings were insufficient for diagnosis but a sufficient indication for further instrumental tests. CT slices were 1 mm, with .5 mm feed; the images were reconstructed on the coronal and sagittal planes (2 mm thickness and 2 mm gap) with a CT Sytec 3000 unit (GE Systems, Milwaukee, WI, USA). RESULTS: The patients positive for meniscal fracture were submitted to arthroscopy and operated on if positive arthroscopically. We had 164 surgical cases even though the meniscus was damaged in 236 cases. CT was negative in 16 of 164 surgical cases. The meniscal injury was demonstrated with both CT and arthroscopy in 236 cases; there were 8 false positives and 32 questionable cases. In the latter, arthroscopy showed 24 cases of meniscal degeneration and 8 horizontal fractures. Diagnostic accuracy was 96%. CT showed the 8 false positives as radial injuries of the free margin, but in fact they were false images caused by a normal fold which increases in knee valgus. DISCUSSION AND CONCLUSIONS: HRCT is more reliable than conventional CT (diagnostic accuracy: 96% vs 85-90%) and MRI (90% reliable). The use of thin slices also permitted to show that a meniscal tissue interruption on the radial margin is not referrable to fracture, as indicated also in the recent literature, but to a normal fold.

Adolescent↗
PubMed1997

Glutamate stimulates 2-deoxyglucose uptake in rat cerebellar granule cells.

Although glutamate is the most widely used excitatory neurotransmitter in mammalian brain a prolonged exposure of neurons to this amino acid causes their degeneration and death, an event also referred to as excitotoxicity. Since one of the earliest events of excitotoxicity is an impairment of energy metabolism, we have assessed whether such damage is due to a concomitant alteration of glucose uptake in rat cerebellar granule cells. We report that glutamate rather than inhibiting actually activates glucose uptake in a time- and temperature-dependent fashion and that this effect is completely blocked by MK-801, a specific inhibitor of glutamate receptors of the NMDA type. Moreover, while the rate of glucose uptake is constant between 2 DIV and 10 DIV, the extent of glutamate-triggered increase above the basal level is undetectable at 2 DIV and becomes progressively higher with days of incubation in cultures, in a fashion overlapping the appearance of functionally active glutamate receptors. The action of this excitatory amino acid is also mimicked, to various extents, by other glutamate agonists such as kainate, NMDA and quisqualate. The glutamate stimulation of glucose uptake occurs in the same range of concentrations as those necessary to cause neuronal death. These findings are discussed in the light of the possible metabolic mechanism responsible of such activation and in connection with previous similar studies performed on glial or mixed glial-neuronal cultures, whereby the stimulating action of glutamate is achieved via alternate pathways not involving glutamate receptors.

Animals↗
PubMed1997

Glutamate neurotoxicity in rat cerebellar granule cells: a major role for xanthine oxidase in oxygen radical formation.

To gain insight into the mechanism through which the neurotransmitter glutamate causally participates in several neurological diseases, in vitro cultured cerebellar granule cells were exposed to glutamate and oxygen radical production was investigated. To this aim, a novel procedure was developed to detect oxygen radicals; the fluorescent dye 2',7'-dichlorofluorescein was used to detect production of peroxides, and a specific search for the possible conversion of the enzyme xanthine dehydrogenase into xanthine oxidase after the excitotoxic glutamate pulse was undertaken. A 100 microM glutamate pulse administered to 7-day-old cerebellar granule cells is accompanied by the onset of neuronal death, the appearance of xanthine oxidase, and production of oxygen radicals. Xanthine oxidase activation and superoxide (O2.-) production are completely inhibited by concomitant incubation of glutamate with MK-801, a specific NMDA receptor antagonist, or by chelation of external calcium with EGTA. Partial inhibition of both cell death and parallel production of reactive oxygen species is achieved with allopurinol, a xanthine oxidase inhibitor, leupeptin, a protease inhibitor, reducing agents such as glutathione or dithiothreitol, antioxidants such as vitamin E and vitamin C, and externally added superoxide dismutase. It is concluded that glutamate-triggered, NMDA-mediated, massive Ca2+ influx induces rapid conversion of xanthine dehydrogenase into xanthine oxidase with subsequent production of reactive oxygen species that most probably have a causal involvement in the initial steps of the series of intracellular events leading to neuronal degeneration and death.

Animals↗
PubMed1997

A novel property of adenine nucleotides: sensitivity to helium-neon laser in mitochondrial reactions.

Consideration is made here of the ability of He-Ne laser light to affect both transport and enzymic reactions by acting on substrates. Adenine nucleotides irradiated with 3 Joules/cm2 fluence (10 mW/cm2 fluence rate) showed altered biochemical behaviour when used as substrates for certain mitochondrial reactions in isolated rat liver mitochondria: ADP/ATP antiport and ATP synthase, which allow for oxidative phosphorylation, and adenylate kinase reaction. In order to determine ATP synthase kinetics a specific method was developed which allows for calculation of ADP phosphorylation rate in intact mitochondria. While no change in ATP synthase kinetics was observed as a result of ADP irradiation, adenine nucleotides proved to be sensitive to He-Ne laser irradiation when their interaction with ADP/ATP carrier and adenylate kinase was considered.

Adenine Nucleotides↗
PubMed1996

Rapid uncoupling of oxidative phosphorylation accompanies glutamate toxicity in rat cerebellar granule cells.

A 100 microM glutamate pulse administered to rat cerebellar granule cells causes a very rapid and progressive decrease in both cell and mitochondrial oxygen consumption caused by glucose and succinate addition, respectively. The respiratory control ratio, which reflects the ability of mitochondria to produce ATP, is reduced by 50% within the first 30 min after glutamate addition. Subsequent to glutamate exposure, a progressive decrease of respiratory control ratio to almost 1 was found within the following 3-5 h. The addition of extra calcium had no effect per se on oxygen consumption by cell homogenate.

Animals↗
PubMed1992

Comparison of cemented ceramic and metal-polyethylene coupling hip prostheses in ankylosing spondylitis.

Two groups of patients suffering from ankylosing spondylitis were treated by total hip arthroplasty. Twenty-one patients (37 hips) were treated with cemented metal-polyethylene prosthesis, whereas 18 patients (36 hips) had cemented ceramic coupling implants. The two groups had similar preoperative clinical data. The average follow-up period was seven to eight years for both. Each patient was graded clinically (pain, function, range of motion, deformities) and roentgenographically (radiolucent lines, etc.). Patients with metal-polyethylene implants showed important modifications of the bone around the implant. Clinical and roentgenographic results were relatively good in patients with ceramic implants. The results underline the importance of the friction coupling of the implant.

Adult↗
PubMed1991

Synthesis and antihypertensive activity of pyran oxygen and amide nitrogen replacement analogues of the potassium channel activator cromakalim.

The synthesis and oral antihypertensive activity in conscious spontaneously hypertensive rats of two new series of compounds related to the prototype potassium channel activator cromakalim (1) are described. In the first series, replacement of the benzopyran oxygen atom by nitrogen or methylene led to the 1,2,3,4-tetrahydroquinoline 12 and 1,2,3,4-tetrahydronaphthalene 13, which were both less active than 1. However, in contrast to the equivalent activity found previously for 1 and its dehydrated analogue 28, the dihydronaphthalene 27 was found to be more active than 13. In the second series, replacement of the C(4) amide nitrogen atom in acyclic amides related to cromakalim by methylene gave ketone 16 that was less active than the corresponding amide 15. However, replacement of the 4-acetonyl substituent in 16 by N,N-dimethylacetamido as in compound 22 resulted in a marked enhancement in activity. The compounds described in this paper thus illustrate the importance of the benzopyran oxygen and C(4) substituent on antihypertensive activity in the cromakalim series of potassium channel activators.

Administration, Oral↗
PubMed1990

Arthroprosthetic reimplantation with bioceramics.

The study analyzes the results obtained in 50 cases of arthroprosthetic substitution surgery performed as a result of "aseptic detachment of the implant"; it involves a consecutive series of operations performed between 1979 and 1983. In all of the cases ceramic-ceramic cemented prostheses were implanted. The results, which were generally satisfactory, confirmed the excellent properties of alumina (low wear, elevated tolerance).

Adult↗
PubMed1990

Arthroscopic lateral meniscectomy in adults with stable knees. A medium term evaluation of the results and a comparison with similar lesions of the medial meniscus.

The results obtained in 37 cases of arthroscopic meniscectomy in isolated lesions of the lateral meniscus in adult patients are analysed. Isolated lesions were chosen as it is our belief that the results may be considerably influenced by the presence of ligamentous lesions. After an average follow-up of 33 months the results were: excellent, 32; good, 2; fair, 2; poor, 1. The lowest percentage of improvement was observed in subtotal meniscectomies. The presence of changes in the joint cartilage is not always responsible for mediocre results.

Adolescent↗
PubMed1989

[Expression of the interleukin-2 receptor in T lymphocytes of the rheumatoid synovial membrane].

Indirect immunofluorescence was used to stain DR antigen and interleukin-2 receptor (Tac) of T-lymphocytes (Leu 4+). Tissue samples of synovial membrane were cut from arthroscopic biopsies of inflamed knees in four patients with active rheumatoid arthritis (RA). Consecutive cryostatic sections of rheumatoid sinovium were analysed using monoclonal antibodies. It was found that a high percentage of T-lymphocytes express DR antigen. In contrast the proportion of T cells expressing Tac was small. We conclude that T cell activation in synovial membrane is incomplete, and this disfunction may contribute to the chronic inflammation of RA.

Arthritis, Rheumatoid↗
PubMed1986

The treatment of acetabular fractures.

The results are reported of 52 acetabular fractures treated surgically and followed up for 6 to 16 years. The cases were sufficiently comparable for statistically significant analysis. Satisfactory results were obtained in 34 cases (65%), and poor in 18 (35%). The poor results were due to: epiphyseal necrosis (8%), secondary arthritis (17%), periarticular ossification (9%). The treatment of these poor results is discussed, including the indications for intertrochanteric osteotomy and, in particular, total hip replacement.

Acetabulum↗
PubMed1980

Carpal ankylosis in juvenile rheumatoid arthritis.

Forty-seven of 100 consecutive juvenile rheumatoid arthritis patients with wrist arthritis were found to have ankylosis at the carpal joints. this finding was significantly more frequent in juvenile than in adult rheumatoid arthritis patients. The carpometacarpal wrist segment was the most frequently ankylosed. Ankylosis was not related to any particular feature of the disease, but disease duration was longer in patients with ankylosis. A significant association was found between carpal ankylosis and cervical apophyseal joint fusion.

Adolescent↗