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Biomedical subjects

R Iorio

Publications and source records attributed to R Iorio.

At least 19 recordsLinked to original sources
PubMed2003

Trabecular minimodeling in human iliac bone.

In adult human beings, remodeling creates nearly all of new bone tissue. However, Frost hypothesized that modeling can go on in trabeculae throughout life. As this hypothesis has not been verified, we looked for histologic evidence of trabecular modeling (minimodeling) during bone histomorphometry of transiliac bone biopsy specimens obtained from 34 patients (age range, 38-81 years; mean age, 58.4 years; female, 31/34) at the time of total hip arthroplasty. Before the bone biopsy study, we performed quantitative bone scintigraphy of bilateral hip joints and bilateral iliac crests in 10 other patients with unilateral hip disease and confirmed that the bone biopsy site was not affected by ipsilateral hip joint disease. Patients who had metabolic bone diseases or who had taken medications known to affect bone metabolism were excluded from the study. During modeling where bone formation and bone resorption are not coupled, bone formation can occur on quiescent bone surfaces without preceding bone resorption and create smooth cement lines. Therefore, the combination of fluorochrome labeling and a smooth cement line without interruption of surrounding collagen fibers was regarded as evidence of minimodeling. Histologic evidence of minimodeling was detected in 21 of the entire 34 specimens (62%) and 17 of 27 specimens obtained from postmenopausal patients (63%). Bone volume of minimodeling sites was less than 1% of the trabecular bone volume, and these sites accounted for less than 2% of the entire bone surface on average. However, osteoid volume of minimodeling sites comprised approximately one-tenth of the entire osteoid volume, and their labeled surface constituted one-fourth to half of the entire labeled surface on average. Therefore, when performing bone histomorphometry of adult cancellous bone, minimodeling should be taken into account when dealing with parameters related to osteoid volume and mineralization. A comparison of specimens with and without minimodeling demonstrated that the presence of minimodeling was correlated with smaller physique of patients, accelerated mineralization (as indicated by the higher mean MS/BS and MAR values and the shorter mean Omt), and higher metabolic turn-over of bone (as indicated by the higher mean BFR/BV value). Although the findings still need to be verified in a larger number of normal subjects without hip joint disease, they support Frost's hypothesis that minimodeling can continue throughout human life.

Adult↗
PubMed2003

Mimicry between the hepatitis C virus polyprotein and antigenic targets of nuclear and smooth muscle antibodies in chronic hepatitis C virus infection.

Autoantibodies to smooth muscle (SMA) and nuclear components (ANA) arise in the natural course of chronic infection with hepatitis C virus. In view of the growing evidence for 'molecular mimicry' as a mechanism of autoimmunity we investigated whether cross-reactive immune reactions between host smooth muscle/nuclear components and HCV antigens may contribute to the formation of SMA and ANA in chronic HCV infection. Computer-assisted protein database search methods were used to identify three smooth muscle (smoothelin698-717, myosin1035-1054, vimentin69-88) and three nuclear (matrin722-741, histone H2A11-30, replication protein A133-152) host antigens with the highest local sequence similarity to the HCV polyprotein and 20-mer peptides corresponding to these regions were constructed. Sera from 51 children with chronic HCV infection [median age: 8 (2-16); 27 boys], 26 SMA positive and five ANA positive, were tested for reactivity to the synthesized HCV peptides and their human homologues by enzyme linked immunosorbent assay (ELISA). Sera from patients with HBV infection and chronic liver disease of different aetiologies were used as controls. 'Double reactivity' to HCV peptides and smooth muscle/nuclear homologues was associated strongly with HCV infection (P < 0.001 for both). Humoral cross-reactivity was established as the basis for double recognition by competition ELISA. Double-reactivity to smooth muscle and HCV peptide antigens correlated with SMA positivity by indirect immunofluouresence (P = 0.05). Of 15 patients double-reactive to myosin1035-1054 and its HCV homologue, 13 recognized whole myosin by immunoblot. These results suggest that ANA and SMA in chronic HCV infection may arise, at least in part, as a consequence of cross-reactive immune responses to HCV and host smooth muscle/nuclear antigens.

Adolescent↗
PubMed2002

Possible role for Ca(2+) calmodulin-dependent protein kinase II as an effector of the fertilization Ca(2+) signal in mouse oocyte activation.

The present study shows that Ca(2+) calmodulin-dependent protein kinase II (CaM kinase II) is physiologically activated in fertilized mouse oocytes and is involved in the Ca(2+) response pathways that link the fertilization Ca(2+) signal to meiosis resumption and cortical granule (CG) exocytosis. After 10 min of insemination, CaM kinase II activity increased transiently, then peaked at 1 h and remained elevated 30 min later when most of the oocytes had completed the emission of the second polar body. In contrast, in ethanol-activated oocytes the early transient activation of CaM kinase II in response to a monotonic Ca(2+) rise was not followed by any subsequent increase. Inhibition of CaM kinase II by 20 micromol/l myristoylated-AIP (autocamtide-2-related inhibitory peptide) negatively affected MPF (maturing promoting factor) inactivation, cell cycle resumption and CG exocytosis in both fertilized and ethanol-activated oocytes. These results indicate that the activation of CaM kinase II in mouse oocytes is differently modulated by a monotonic or repetitive Ca(2+) rise and that it is essential for triggering regular oocyte activation.

Animals↗
PubMed2001

Primary Charnley total hip arthroplasty: a comparison of American and Japanese cohorts followed for 10-20 years.

Primary Charnley total hip arthroplasties (THAs) followed for 10 to 20 years were compared between an American (183 sockets and 178 femoral prostheses) and a Japanese (145 sockets and 148 femoral prostheses) series, each performed by a single surgeon at a single hospital using similar techniques. The primary etiology was developmental dysplasia of the hip (70%) in the Japanese series and primary osteoarthrosis (50%) in the American series. Radiographic socket survival was inferior in the Japanese series at 4- to 11-year follow-up, which was attributed mainly to the etiologic difference. The American patients had higher levels of postoperative activity and developed more accelerated polyethylene wear, which may lead to an increased loosening rate of sockets > or = 10 years after THA. The American series had higher rates of femoral revision at > or = 9 years follow-up, which was attributed mainly to lower canal flare indices in that series.

Arthroplasty, Replacement, Hip↗
PubMed2001

Venous thromboembolic disease management patterns in total hip arthroplasty and total knee arthroplasty patients: a survey of the AAHKS membership.

The American Association of Hip and Knee Surgeons (AAHKS) distributed a survey to its members exploring practice patterns implemented to prevent venous thromboembolic disease (VTED) in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). Of 720 (33%) members, 236 responded. Prophylaxis was prescribed for 100% of patients during the course of hospitalization for THA and TKA. Warfarin was the commonest pharmacologic treatment used for THA (66%) and TKA (59%) patients. Low-molecular-weight heparin was used in 16% of THA patients and 18% of TKA patients. The most commonly employed mechanical modality was pneumatic devices in THA (51%) and TKA (50%). Universal acceptance of the need for prophylaxis administration for patients undergoing THA and TKA is shown. The method and duration remain highly variable; although the survey illustrates such variation, it suggests there is no one best method of prophylaxis.

Anticoagulants↗
PubMed2001

Displaced femoral neck fractures in the elderly: outcomes and cost effectiveness.

The optimal treatment for displaced femoral neck fractures in elderly patients is a matter of controversy. Four surgical options are well supported in the orthopaedic literature: reduction with internal fixation, unipolar hemiarthroplasty, bipolar hemiarthroplasty, and total hip arthroplasty. Based on a review of the outcomes literature regarding treatment of femoral neck fractures and a cost-effectiveness analysis, an algorithm for surgical treatment of displaced femoral neck fractures in elderly patients is presented. Cost-effectiveness analysis of these four surgical treatment options shows that arthroplasty is the most cost-effective treatment when complication rate, mortality, reoperation rate, and function are evaluated during a 2-year postoperative period. These data were strongly supported by a two-way sensitivity analysis that varied the effectiveness of the interventions and the costs. Literature derived outcome studies show that elderly patients with displaced femoral neck fractures achieve the best functional results with a well healed femoral neck without osteonecrosis after reduction and internal fixation. Achieving this result may be difficult, and it is not as cost effective as arthroplasty.

Arthroplasty, Replacement, Hip↗
PubMed2001

An epidemiological survey of hepatitis C virus infection in Italian children in the decade 1990-1999.

BACKGROUND: A retrospective-prospective survey of Italian children with hepatitis C virus (HCV) infection was planned in 1998 to explore the epidemiologic features of infection during the past decade. METHODS: Anti-HCV-positive patients (or HCV RNA-positive infants) aged 1 month to 16 years, consecutively observed in 20 pediatric Institutions, were considered. An anonymous epidemiologic questionnaire based on clinical records was used. RESULTS: From 1990 through March 1999, 606 patients were observed (296 boys, average age 5.8 years). Maternal infection (46% of cases) and blood transfusions (34%) were the most frequent risk factors. Of 279 infected mothers, 61% did not recall a putative source of infection (by history, many could possibly have had exposure through routes such as therapeutic injections with nondisposable material), whereas 94 (34%) admitted drug abuse, including 49 (17%) coinfected with human immunodeficiency virus (HIV). Only 157 (26%) children were born after 1991: 90% of their mothers were infected (11% were HIV coinfected vs. 25% mothers of older children, P < 0.01). CONCLUSIONS: Maternal infection is a prominent source of pediatric HCV infection in Italy. The fact that most mothers had a history of covert exposure to HCV, probably through percutaneous routes that are no longer operating, and that the number of those with HIV coinfection has decreased suggests that the frequency of pediatric infection could decrease in the future.

Adolescent↗
PubMed2000

Predictive value of Epstein-Barr virus genome copy number and BZLF1 expression in blood lymphocytes of transplant recipients at risk for lymphoproliferative disease.

Epstein-Barr virus (EBV) genome numbers and RNA transcripts from the immediate-early EBV gene BZLF1 were monitored by means of polymerase chain reaction in peripheral blood lymphocytes (PBLs) of 44 children who received liver transplants. The 2 tests were compared, using several parameters to assess their value as predictors of posttransplantation lymphoproliferative disease (PTLD). All patients were infected with EBV. BZLF1 mRNA was positive in 70% of patients, with highest expression in those with largest virus load. Four patients developed PTLD that could not be unequivocally diagnosed by any of the parameters considered alone. Sensitivity of EBV genome number (>/=40,000 EBV copies/10(5) PBLs) and BZLF1 mRNA (BZLF1:glyceraldehyde-3-phosphate-dehydrogenase ratio >/=0.5) was 100%. Specificity of each of the 2 tests alone (98% and 58%, respectively) improved (to 100% and 83%, respectively) when measurement of serum IgG level was included. Because decreased virus load, but not BZLF1 mRNA expression, accurately predicted favorable responses of PTLD to therapy, monitoring of EBV genome numbers alone appears sufficient in children with liver transplants.

Adolescent↗
PubMed2000

Poor bone quality or hip structure as risk factors affecting survival of total-hip arthroplasty.

BACKGROUND: The principal long-term complication after total hip arthroplasty (THA) has been aseptic fixation failure. Many hip prostheses and operative techniques have been developed to improve outcomes, but few measures have been taken to cope with poor bone quality or hip structure. We assessed risk factors for aseptic fixation failure after THA. METHODS: We assessed, by multivariate analysis, survival of 405 primary Charnley THAs to identify risk factors for aseptic fixation failures. We also investigated risk factors for development of rapid polyethylene wear (penetration depth of the femoral head into the socket polyethylene > or = 2 mm/year) FINDINGS: In the entire series of 405 THAs, with use of radiographic fixation failure or revision for a loose socket as the endpoint, development of rapid polyethylene wear and the preoperative diagnosis of atrophic osteoarthrosis (defined by scarce osteophyte formation) were identified as risk factors for socket loosening (p < or = 0.02). A medullary canal with an unfavourable geometry (a stovepipe canal, Noble's canal-flare index < 3.0) was the only risk factor for femoral fixation failure (p < or = 6.7x10(3)). The only variable related to development of rapid polyethylene wear was the type of steel used in the femoral prosthesis--Ortron 90 prostheses significantly lowered the rate of development of rapid wear from 12.7% to 0.4%. In the 248 THAs in which these femoral prostheses were used, socket survival was affected only by the preoperative diagnosis of atrophic osteoarthrosis (for radiographic fixation failure and revision, p=4.0x10(-5) and p=0.042, respectively). INTERPRETATION: In THA, the critical risk factors are poor bone quality, which manifests as atrophic osteoarthrosis, for socket survival and poor bone structure for femoral-prosthesis survival. To ensure longer durability of THAs, these factors should be assessed further and efforts, especially biological initiatives, should be made to resolve them.

Arthroplasty, Replacement, Hip↗
PubMed2000

The association of excessive warfarin anticoagulation and postoperative ileus after total joint replacement surgery.

Patients undergoing joint replacement who show signs of ileus in the postoperative period that require insertion of a nasogastric tube (NGT) must be monitored closely to avoid bleeding complications. The diagnosis of postoperative ileus was documented in 40 of 2,526 (1.6%) consecutive joint replacement operations between January 1, 1990, and March 1, 1998, at 1 hospital. Of the 40 patients with postoperative ileus, 34 received warfarin postoperatively. Of these 34 patients, 19 required a NGT for >48 hours, and 15 patients required a NGT for <48 hours or did not require a NGT. Of the 19 patients who required a NGT for >48 hours and who received warfarin anticoagulation, 17 had a prothrombin time of >20 seconds or an international normalized ratio (INR) of >2.0. None of the 15 patients who required a NGT for <48 hours and who received warfarin anticoagulation had a prothrombin time of >20 seconds or an INR of >2.0. This difference was highly statistically significant (P < .001).

Anticoagulants↗
PubMed2000

Athletic activity after total knee arthroplasty.

Americans are aging, elderly Americans are more active, and the prevalence of total knee arthroplasty is increasing. Indications for knee replacement include pain, deformity, and a desire to improve function. When patients have knee replacement operations, frequently they increase their activities. It is important for patients with knee replacements to understand the impact of athletic activity on the outcome of knee replacements. Orthopaedic surgeons should educate patients regarding athletic activity after total knee arthroplasty. Considerations and risk factors for athletic activity after knee replacements include athletic activity before surgery, preoperative rehabilitation, surgical reconstruction, implant failure or fracture, implant fixation or loosening, and joint bearing surface wear. Anatomic reconstruction and compulsive postoperative rehabilitation with restoration of muscular control are important for optimum function after total knee arthroplasty. In general, patients with knee replacements are encouraged to participate in low-impact, low-demand sports, and to avoid high-impact, high-demand sports.

Arthroplasty, Replacement, Knee↗
PubMed2000

The role of bladder catheterization in total knee arthroplasty.

The use of a urinary bladder catheter in the perioperative period for patients undergoing total knee arthroplasty is controversial. In the current study, two bladder management protocols were studied. One group of patients had an indwelling catheter inserted into the bladder before total knee arthroplasty. The other group of patients was observed and treated for urinary retention as necessary. From 1993 to 1998, 652 patients undergoing primary, unilateral total knee arthroplasty were randomized by surgeon into two groups: one group underwent preoperative insertion of an indwelling bladder catheter (306 patients), and one group (346 patients) had a catheter inserted postoperatively as necessary. Sixty-six percent (229 of 346) of these patients required catheterization (203 had indwelling catheters and 26 had intermittent straight catheters). A urinary tract infection developed in five patients (1.6%) in whom a catheter was inserted preoperatively. A urinary tract infection developed in six patients (1.7%) in whom a catheter was inserted if necessary. Five of these urinary tract infections developed in patients with delayed indwelling bladder catheters. A urinary tract infection did not develop in any patient in whom a straight catheter was inserted. There was no significant difference in the length of stay in the hospital between the two groups. The group in whom a catheter always was inserted generated $491 greater cost for total knee arthroplasty than patients in whom a catheter was inserted if necessary.

Adult↗