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Biomedical subjects

A Ferretti

Publications and source records attributed to A Ferretti.

121 records · Page 7Linked to original sources
PubMedDate not supplied

Open capsulorrhaphy with suture anchors for recurrent anterior dislocation of the shoulder.

Forty of 42 consecutive open capsulorrhaphies with suture anchors for treatment of traumatic recurrent anterior dislocation of the shoulder were reviewed after a minimum follow-up of 2 years. Two patients were lost to follow-up. Follow-up was conducted according to the rating systems of Rowe and the Society of American Shoulder and Elbow Surgeons. The surgical outcome was satisfactory in 38 patients (95%). Eighteen of the 22 patients who were involved in competitive overhead or collision sports before surgery returned to their preoperative sports levels. One patient, whose operation was unsuccessful, experienced recurrent dislocation. In one patient a deep infection that occurred as a complication of the surgical technique healed after suture anchor removal. Although a longer follow-up is necessary, this technique appears to have encouraging results as it avoids the risks related to the use of screws and staples.

Adolescent↗
PubMedDate not supplied

Injury of the suprascapular nerve at the spinoglenoid notch. The natural history of infraspinatus atrophy in volleyball players.

From 1985 to 1996, we observed 38 cases of isolated atrophy of the infraspinatus muscle in athletes; all were involved in volleyball at a competitive level. There were 20 men and 18 women with a mean age of 26 years (range, 15 to 27). At the time of the first examination, 35 of these athletes had no pain and were treated with exercises to strengthen the external rotators. The remaining three patients underwent surgery because of pain at the posterior aspect of the shoulder. Sixteen of the 35 players treated nonoperatively were reviewed at a mean follow-up of 5.5 years (range, 3 to 10). Thirteen were still involved in volleyball and three had retired symptom-free at the end of their careers. On physical examination, atrophy of the infraspinatus muscle was unchanged in all cases. The patients treated surgically were reviewed at a mean follow-up of 2 years. All of them were able to play volleyball at their preinjury levels, but one had pain at the anterior aspect of the shoulder after strenuous activity. Physical examination showed a notable reduction of the atrophy in one patient. Entrapment of the suprascapular nerve at the spinoglenoid notch is a usually painless syndrome that is frequently observed in volleyball players. Surgical treatment is indicated in the rare cases of painful neuropathies after careful patient selection.

Adolescent↗
PubMedDate not supplied

Epidemiology of jumper's knee.

Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

Age Factors↗
PubMedDate not supplied

[Health databases to assess the incidence of lymphoid malignancies in Italian population].

We tested the usefulness of the National Health Service Databases for investigating the incidence of lymphoid malignancies in an Italian community. We analyzed hospital discharge data, drug prescription, pathologic records and death certificates to identify the new cases of Hodgkin's disease, non Hodgkin's lymphoma, multiple myeloma, and acute and chronic lymphocytic leukemia diagnosed in the municipal population of Reggio Emilia, northern Italy, 1991 through 1996. The completeness of Hospital discharge data was very high, and several incident cases could be identified only through this source. Completeness of the pathologic registry was satisfactory for Hodgkin's disease and non-Hodgkin's lymphoma, and this source independently yielded a few incident cases of lymphoid neoplasms. Analysis of death certificates and drug prescriptions appears to be of limited value in the epidemiology of lymphoproliferative diseases.

Databases as Topic↗
PubMedDate not supplied

Viscoelastic properties of the semitendinosus and gracilis tendons in reconstruction of the ACL: an in vivo evaluation.

Tensioning of the tendons of the semitendinosus and the gracilis used to reconstruct the anterior cruciate ligament (ACL) of the knee is one of the main factors to take into consideration during surgery that aims at obtaining good postoperative joint stability. Some authors have shown in vitro that the viscoelastic nature of the patellar tendon is responsible for its gradual release (loss of tension). It is the purpose of this study to verify in vivo the biomechanical behavior of the semitendinosus and gracilis tendons. A total of 40 consecutive patients were submitted to reconstruction of the ACL with flexor tendons of the knee using a method that allows for the gradual tensioning of the doubled semitendinosus and gracilis tendons using the Swing Bridge method. Patients were divided into 2 groups: in the first 20 patients (group I), after adequate manual pretensioning and tibial and femoral stabilization, the tendons were twisted using a dynamometer to measure torsion forces until tensioning equal to 2.5 N was achieved. The control group (group II) was made up of the successive 20 patients in whom tensioning of the tendons at 2.5 N was carried out in many phases. Five minutes after initial tensioning at 2.5 N the decrease in tension was recorded that returned to initial values. A similar procedure was carried out after 5 more minutes. The patients in both groups were evaluated using a KT-1000 arthrometer one year after surgery. The patients in group II showed a decrease in torsion equal to 37.2% after the first 5 minutes, and a further 26.8% after 5 more minutes, and measurement by means of KT-1000 revealed mean values for S/S 30 lb. and S/S MM of 1.3 mm and 1.7 mm, respectively, that proved to have a statistically significant difference (p < 0.05) as compared to the patients in group I (S/S 30 lb.: 2.0 mm; S/S MM: 2.4 mm). Although these data do not provide indications on the amount and duration of pretensioning and definitive tensioning to be applied to the transplant, they do clearly show the viscoelastic properties of the tendons. These properties require a more in-depth study to better determine the exact tensioning of the neoligament.

Adolescent↗
PubMedDate not supplied

Reconstruction of the anterior cruciate ligament with the tendons of the semitendinosus and gracilis doubled: a comparison with reconstruction using the patellar tendon.

A total of sixty consecutive cases of anterior chronic laxity of the knee the pre- and intraoperative features of which corresponded to the criteria of inclusion considered, hospitalized in our institute between September and December 1998 and submitted to reconstruction of the ACL were reviewed at a follow-up of 74 months. The series was made up of two groups that were homogeneous in terms of sex, age, degree of preoperative laxity and number and type of associated meniscal lesions; in the first group (20 cases) reconstruction was carried out using the patellar tendon (BPTB) and in the other (40 cases) the doubled semitendinosus and gracilis tendons (DGST) were used with the association in cases with greater rotatory laxity (20 cases) of peripheral reinforcement reconstruction. An accelerated rehabilitation protocol was used in the first group, a more prudent one with immobilization in extension for two weeks was used in the second group. The results, evaluated based on the IKDC form, appeared to be better in the DGST group, with a statistically significant difference; joint stability, evaluated at follow-up with a KT1000 arthrometer also proved to be better in the DGST group, with a difference that was not statistically significant. The present study seems to show that reconstruction of the ACL with DGST, a prudent rehabilitation protocol and peripheral reinforcement reconstruction in selected cases is capable of providing better long-term results as compared to standard reconstruction with the patellar tendon and accelerated rehabilitation protocol. Among methods used to reconstruct the anterior cruciate ligament (ACL), those that utilize the central third of the patellar tendon (BPTB) or the semitendinosus and gracilis tendons (DGST) continue to be those used most frequently. Although the debate between orthopedics is still going on as to which of the two methods is to be preferred, studies that compare the two methods do not seem to report essential differences in medium-term results. In a recent meta-analysis of the most important international literature, to this regard Freedman et al. concluded that despite a significant major presence of anterior pain reconstruction with BPTB is capable of guaranteeing better joint stability and patient satisfaction, with a minor incidence of transplant failure. Nonetheless, if methods of reconstruction with BPTB seem to be rather standardized in terms of the method used to obtain the specimen and that used for stabilization (with very few differences between interference screws and transverse stabilization), and in postoperative rehabilitation (so-called accelerated), when DGST is used there are many technical variables capable of influencing the final results (choice of methods of stabilization, postoperative rehabilitation in particular). For this reason we still cannot obtain an absolute comparison of the two methods, but can only compare reconstruction with BPTB and a particular method used with DGST. It is the purpose of this study to present the medium-term results not so much of ACL reconstruction with the semitendinosus and gracilis doubled, but as a more articulate approach to the pathology of the ACL, so that DGST is only one phase, even if it is the most important one. Because we wished to verify whether it is possible, even in terms of joint stability and patient satisfaction, to improve the results of the so-called gold standard for reconstruction of the ACL, reconstruction by BPTB with transverse femoral reconstruction and accelerated postoperative rehabilitation protocol was chosen as a term of paragon.

Adult↗
PubMedDate not supplied

Pentose phosphate pathway alterations in multi-drug resistant leukemic T-cells: 31P NMR and enzymatic studies.

31P NMR studies were carried out on the parental drug-sensitive human T-lymphoblastoid cell line CCRI-CEM (CEM) and its multi-drug-resistant (MDR) CEM-VBL100 variants, to assess the role of the pentose phosphate (PP) in MDR expression. CEM and CEM-VBL100 were incubated in the presence of 2-deoxyglucose, as recently proposed by our group (Clin. Chim. Acta 208: 39, 1992). Accumulation of 2-deoxyglucose 6-phosphate was much lower in the drug-resistant than in sensitive cells, indicating PP shunt activation in the MDR variants. This result was confirmed by enzymatic analyses, which demonstrated that, with respect to the parental line, the MDR variant was characterized by a) unaltered hexokinase activity; b) higher glucose 6-phosphate dehydrogenase activity; c) increased levels of reduced glutathione and marked increase of glutathione peroxidase activity after cell exposure to an oxidizing agent (tert-butylhydroperoxide). These results support the view that cell detoxification mechanisms mediated by the pentose phosphate pathway may contribute to the expression of MDR in tumours.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Detection of neutral active phosphatidylcholine-specific phospholipase C in Friend leukemia cells before and after erythroid differentiation.

With respect to normal tissues, 31P NMR spectra of tumors usually exhibit elevated phosphomonoester (PME) and phosphodiester (PDE) signals, arising from phospholipid metabolites such as phosphocholine (PCho) and glycerophosphocholine (GroPCho) (and/or ethanolamine analogues). PME and PDE resonances may undergo significant alterations during tumor growth, at early stages of tumor response to treatment or following cell differentiation and maturation. The enzymatic mechanisms which regulate these alterations are scarcely understood. Recent studies on agonist-induced phosphatidylcholine (PC) hydrolysis by PC-specific phospholipase C (PC-plc) in cells stimulated by hormones or growth factors suggest the hypothesis that repeated transient activations of this enzyme may also contribute to the elevation of PCho levels in tumor NMR spectra. This paper reports the first direct evidence on neutral active PC-plc activity in a tumour cell system, Friend leukemia cells, either in the undifferentiated (FLC) or differentiated state (dFLC). Cell homogenates were incubated in the presence of mixed diheptanoylphosphatidylcholine/sphingomyelin unilamellar vesicles (SLUV), which were previously shown to represent a good substrate for bacterial plc. 31P NMR analyses allowed the simultaneous detection and quantification of phosphorylated metabolites produced in tumor cell homogenates by PC-plc activity, as well by enzymes active in the PC deacylation pathway. With respect to FLC, dFLC homogenates exhibited higher PC-plc activity and lower accumulation of a deacylation product, GroPCho, in agreement with the elevation in the [PCho]/[GroPCho] ratio, already reported in 31P NMR spectra of intact differentiated cells. The direct detection of PC-plc in this cell system opens novel biochemical interpretations on a series of oncological observations, such as a) transient increases in the levels of PCho and PC-derived diacylglycerols reported in immature or in transformed cells in response to agonist-receptor interactions and b) accumulation of mobile lipids in tumor cell membranes and tissues.

Animals↗
PubMedDate not supplied

Detection of phosphatidylcholine-specific phospholipase C in NIH-3T3 fibroblasts and their H-ras transformants: NMR and immunochemical studies.

Although evidence supports constitutive activation of phosphatidylcholine specific phospholipase C (PC-plc) in rastransformed fibroblasts, no studies have been devoted to measure the basal activity levels of this enzyme, its molecular characteristics and subcellular localization. This paper reports for the first time measurements of the activity of different enzymes responsible for PC hydrolysis (PC-plc; phospholipases A2 (pla2) and A1 (pla1)) in homogenates of murine NIH-3T3 fibroblasts (3T3) and their transformants obtained by human H-ras transfection (3T3ras). To this end, 31P NMR analyses were carried out on total cell homogenates, incubated in the presence of mixed diheptanoylphosphatidylcholine: sphingomyelin (DHPC:SM) unilamellar vesicles (SLUV), in which DHPC acts as a suitable substrate for water-soluble lipolytic enzymes. The basal PC-plc activity levels (0.66 +/- 0.14 and 0.38 +/- 0.10 nmol/10(6) cells.hour in 3T3 and 3T3ras fibroblasts, respectively),were substantially higher (over 30-50x) than those reported in the literature for normal mammalian cells (dog heart myocytes). Moreover the PC-plc activity was about 15-30 times lower than the overall PC deacylation activity in both clones. The use of high titer polyclonal antibodies, raised in a rabbit against bacterial PC-plc, allowed identification of one cross-reactive mammalian PC-plc component (M(r) 66 kD) in cell lysates of both 3T3 and 3T3ras fibroblasts, and detection, by indirect immunofluorescence, of its subcellular localization. In control 3T3 fibroblasts (in the late log-phase of growth) the enzyme was exclusively located in the cytosol, while in H-ras transformed cells it was massively exposed on the external side of the membrane. This new finding strongly suggests that the oncogenic product p2Iras is able to induce (or mediate) translocation of PC-plc across the plasma membrane of ras transformed cells, with possible implications not only on cell biochemistry (enhancement of PC-plc activity, and consequent production of intra- and extracellular PCho and accumulation of neutral lipids) but also on cell-cell interaction mechanisms which facilitate tumour invasion and metastasis of oncogene-transformed cells.

3T3 Cells↗