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Biomedical subjects

F Greco

Publications and source records attributed to F Greco.

At least 55 records · Page 3Linked to original sources
PubMed1996

Fetal chondral homografts in the repair of articular cartilage defects.

Lesions of the articular cartilage were bilaterally induced in the patella and the femoral condyle of adult NZW rabbits. A fresh fetal chondral homograft was implanted in one side, the untreated side serving as control. Fetal chondral tissue appeared to survive when implanted at the site of articular injury in adult animals, with no histological evidence of cell-mediated immune response. Fetal chondroblasts showed some signs of maturation and induced endochondral ossification at the base of the graft, with sound anchoring of the graft to the host tissue. In most cases, the homograft fused directly with the adjacent articular cartilage restoring the continuing of the articular surface. However, at implantation the graft could not be easily kept in place, and therefore some grafts had poor mechanical stability. Condylar grafts were incorporated better than patellar grafts. The healing process seemed to be related to the mechanical stability of the graft and to the anatomical site of injury.

Animals↗
PubMed1995

Hydroxyapatite-coated hip prostheses. Early results from an international study.

A hydroxyapatite-coated hip prosthesis designed to stimulate proximal femoral stress transfer was studied in 222 patients undergoing primary total hip arthroplasty with a minimum followup of 2 years. The femoral component was a roughened titanium alloy with a 50-mu coating of hydroxyapatite applied to the proximal third. A proximal press-fit technique was applied with distal femoral over-reaming as standard procedure. The hydroxyapatite-coated acetabulum was of hemispherical design. Analysis of the clinical results showed a mean Merle D'Aubigné score of 16.7 points at 6 months and 17.4 points at 2 years. Mild residual thigh pain of unknown origin was reported in 3.6% of patients at 2 years. Radiographic evaluation showed complete acetabular and proximal femoral osseointegration without any loosening. No radiolucency or reactive line formation was observed around the hydroxyapatite-coated areas of the prostheses. Femoral bone densification occurred at the coated-uncoated transition zone (54%); 4% to 6% of cases showed cortical hypertrophy at the uncoated area of the stem. Reactive lines were seen around the distal stem in 52% of patients after 2 years. The clinical outcome was excellent, and the radiographic data pointed mainly to proximal femoral stress transfer.

Adult↗
PubMed1994

Hepatitis C virus infection in patients with non-Hodgkin's lymphoma.

Hepatitis C virus (HCV), which is both a hepatotropic and a lymphotropic virus, has been proposed as a possible causative agent of mixed cryoglobulinaemia. This 'benign' lymphoproliferative disorder can switch over to a malignant B-cell non-Hodgkin's lymphoma (NHL). Therefore HCV infection has been investigated in a series of 50 unselected Italian patients with B-cell NHL. Antibodies against HCV were found in 30% of NHL and HCV viraemia in 32% of cases. HCV-related markers were detected in 34% (17/50) of our NHL patients; this prevalence is particularly significant when compared with HCV seropositivity in Hodgkin's lymphoma (3%) and healthy controls (1.3%).

Adult↗
PubMed1994

Hepatitis C virus chronic infection as a common cause of mixed cryoglobulinaemia and autoimmune liver disease.

OBJECTIVES: Mixed cryoglobulinaemia (MC) and autoimmune chronic hepatitis (AI-CH) are frequently associated with hepatitis C virus (HCV) chronic infection. Because HCV represents a possible common aetiological factor, the aim of the present study is to investigate the clinico-serological alterations of both MC and AI-CH and to verify a possible overlap between these disorders. SETTING: Patients from three tertiary referral centres. SUBJECTS: Two Italian series of 88 MC patients and 30 AI-CH type 1 were studied. RESULTS: MC and AI-CH share several clinico-serological features. The patients' mean age (MC vs. AI-CH: 60 +/- 9 vs. 57 +/- 13 years), disease duration (10.5 +/- 5 vs. 9.6 +/- 6 years), and female/male ratio (3.4 vs. 3.3) were very similar in the two series. Typical hallmarks of MC, i.e. purpura, arthralgias, and weakness, circulating mixed cryoglobulins with rheumatoid factor activity, and hypocomplementemia were also recorded in a significant number of AI-CH patients. Similarly, chronic active hepatitis was found in 68% of MC patients and its histological and serological alterations were comparable with those of AI-CH; moreover, amongst various autoantibodies, antinuclear antibodies and/or anti-smooth-muscle antibodies were detected in half of the cases of MC. Anti-HCV antibodies, detected by second-generation Chiron ELISA and RIBA, were present in a high percentage of both MC and AI-CH (94 vs. 80%), and frequently associated with HCV viraemia (86 vs. 77%). Finally, anti-GOR, the HCV-related autoantibodies, were found in half cases of MC and AI-CH. CONCLUSIONS: On the whole, these data suggest that HCV in combination with other infectious and environmental and genetic factors can trigger a complex immunological disorder with different clinical patterns.

Aged↗
PubMed1994

[Caloric intake in parenteral nutrition of very low weight infants].

To evaluate the efficacy of a measure able to compare energy intake from parenteral and enteral nutrition we documented growth patterns in a group of VLBW infants treated with parenteral nutrition (PN). To analyze comparative energy intake from the two sources we expressed a percentage of both parenteral and enteral calories: the former (RCP%) related to an optimal value of 85 non protein calories and the latter (RCE%) to an optimal value of 150 total calories. Total energy intake was planned on the RCT% (RCP% + RCE%). We studied 75 VLBW infants with a mean BW of 1040 g and a mean GA of 29.5 weeks. The mean duration of PN was 25.8 +/- 10.4 days. The initial weight loss (10.2 +/- 5.3%), the time to regain BW (5.5 +/- 4 days) and the day of lowest weight (5.2 +/- 1.6 day of life) were in the normal range; the subsequent growth rate resulted 25.9 +/- 9.2 g/kg/die and did not change for different GA or BW. Growth pattern about head circumference and length were above the third percentile. The mean age of RCT% = 100% was 11.4 +/- 4.8 days of PN; this value was higher for the more premature infants. Severe metabolic abnormalities were not detected. Our observations show the efficacy of the RCT% as index of energy from both enteral and parenteral source during PN: the growth pattern seems to be quite satisfactory without any severe metabolic complication.

Energy Intake↗
PubMed1994

Age-related distribution of elastic fibers in the rabbit knee.

The distribution and histochemical properties of elastic fibers in the knee of newborn, young, adult, and old New Zealand White rabbits were studied. In the growing rabbit, elastic fibers, especially oxytalan fibers, are abundant in the perichondrium and the fibrous layer of the periosteum. They are homogeneously distributed in tendons, ligaments, and menisci, and are absent in the epiphyseal cartilage and growth plate and at the enthesis. In mature rabbits, the articular capsule, the synovial membrane, the peritenon, the periosteum, the perimysium, and the perivascular connective tissue are rich with elastic fibers. They are rarer in the tendon and are absent at the enthesis, in bone and articular cartilage. In the meniscus, the fibers are distributed centripetally. The distribution of elastic fibers is probably related to the different functional role and biomechanical behavior of each tissue. Finally, the type of elastic fiber in the various tissues changes with age; younger animals have more oxytalan fibers than adult animals. A gradual process of maturation and specialization of the network of elastic fibers takes place with age.

Aging↗
PubMed1993

Infection of peripheral blood mononuclear cells by hepatitis C virus in mixed cryoglobulinemia.

A striking association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia (MC) has been shown; thus, HCV seems to play an important etiopathogenetic role in this lymphoproliferative disorder. Because HCV is both a hepatotropic and lymphotropic virus, this study aimed to investigate the prevalence of HCV infection of peripheral blood mononuclear cells (PBMCs) in a series of 16 patients with type II (IgMk) MC. Antibodies against HCV were detected by commercially available kits (Second Generation Chiron enzyme-linked immunosorbent assay [ELISA] and recombinant-based immunoblot assay [RIBA]), and the presence of HCV RNA was evaluated in both sera and isolated PBMCs using the polymerase chain reaction technique. A previous exposure to HCV was shown by ELISA and confirmed by RIBA in all cases (100%). Moreover, HCV RNA was present in the sera of 8 of 16 patients (50%), whereas its frequency markedly increased (13 of 16 [81%]) when genomic sequences were detected in peripheral lymphocytes. HCV RNA was never detected in the PBMCs of 20 control subjects. These findings showed that HCV infection, alone or in combination with other factors, may be responsible for the clonal B-cell expansion underlying the systemic manifestations of MC, and may explain the appearance of a malignant non-Hodgkin's lymphoma in some subjects.

Aged↗
PubMed1993

Interferon-alpha in mixed cryoglobulinemia patients: a randomized, crossover-controlled trial.

The effects of interferon-alpha (IFN-alpha) on clinical and serologic manifestations of mixed cryoglobulinemia (MC) were investigated by randomized, crossover-controlled trial in 26 patients. The trial alternated 6 months with and 6 months without IFN-alpha therapy (2 x 10(6) IU daily for a month, then every other day for 5 months). In 22 patients, pretreatment steroid dosage remained unchanged during the study. Six patients dropped out (three because of side effects), whereas another 20 patients experienced a significant improvement of purpura (P < .02) and serum transaminases (P < .005) during IFN-alpha treatment. The presence of clinical improvement was supported by the outcome measurements of several immunologic parameters. In particular, serum cryoglobulins were significantly reduced (P < .04) during IFN-alpha therapy. A rebound phenomenon of clinical and serologic parameters was observed after IFN-alpha discontinuation. In addition, no variations were recorded during 6 months without therapy. Hepatitis C virus (HCV) RNA was detected in 91% (20/22) of our MC patients; in 2/13 cases HCV RNA was no longer detectable in serum samples after IFN-alpha therapy. Thus, IFN-alpha could be considered as treatment for MC in patients with HCV seropositivity.

Alanine Transaminase↗
PubMed1993

Hepatitis C virus-related autoimmunity in patients with porphyria cutanea tarda.

Hepatitis C virus (HCV) infection is frequently found in autoimmune hepatitis and mixed cryoglobulinaemia. In these conditions HCV could be responsible for immuno-mediated organ alterations. The aim of this study was to evaluate the presence of immunological alterations in PCT patients, in which HCV infection has been frequently found. Twenty-three PCT patients were evaluated for clinical and serological alterations, including: chronic hepatitis, other systemic symptoms, serum cryoglobulins and rheumatoid factor (RF), haemolytic complement, serum immunoglobulins, anti-nuclear (ANA), anti-smooth muscle (ASMA), anti-liver-kidney-microsomal (anti-LKM1), anti-soluble-liver-antigen (SLA), anti-mitochondrial (AMA), anti-GOR antibodies, anti-HCV and HCV RNA. Abnormal serum ALT were present in the majority of cases (20/23, 87%), while liver biopsy revealed a chronic persistent hepatitis or chronic active hepatitis in 15/20 (75%) PCT patients. In a high percentage of subjects (91%) the presence of anti-HCV was detected by ELISA and RIBA II (Chiron, Emeryville CA, USA). In 17/22 (77%) cases the ongoing HCV replication in the serum was demonstrated by the detection of HCV genomes (polymerase chain reaction). The prevalence of both anti-HCV and HCV RNA in PCT was significantly higher if compared to 22 systemic immunological diseases (P < 0.001) and 47 healthy subjects (P < 0.001). A possible HCV-induced autoimmunity in PCT was suggested by the presence of the following immunological parameter alterations: anti-GOR in 13/23 (57%), ANA in 4/23 (17%), ASMA in 18/23 (78%), anti-LKM1 in 1/23 (4%), RF in 23/23 (100%), mixed cryoglobulins in 4/23 (17%), complement consumption in 10/23 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Chronic staphylococcal osteomyelitis: a new experimental rat model.

A rat model of chronic staphylococcal osteomyelitis was developed. Fibrin glue (5 microliters) and Staphylococcus aureus (2 x 10(6) CFU/5 microliters) were inoculated into the proximal metaphysis of the tibia. The rats were killed at intervals of between 1 and 6 months, and the tibias were removed. Induced lesions were evaluated by radiographic, macroscopic, and histological examinations and bacterial counts. Roentgenograms revealed osteomyelitis in more than 90% of the tibias. Gross bone pathology revealed skeletal deformation, new bone formation, abscesses, and draining skin fistulas in more than 80% of cases. Histological examination revealed osteomyelitis in more than 90% of cases, and bacterial counts were positive in 86% of cases. Only fibrin glue (5 microliters) was inoculated into controls. Controls showed no osteomyelitic lesions, and counts were negative in seven of eight control tibias. The main feature of this model is the use of fibrin glue instead of the sclerosing agents and foreign bodies used in other models. The model reproduces lesions similar to those of human posttraumatic osteomyelitis and can be reliably used in pathophysiological and therapeutic studies.

Animals↗
PubMed1993

Interferon alfa-2b in mixed cryoglobulinaemia: a controlled crossover trial.

To confirm the positive results of a preliminary trial, 26 patients with mixed cryoglobulinaemia were enrolled in a controlled, randomised, crossover trial with interferon alfa-2b. A significant improvement was seen in the purpura score and alanine aminotransferase activities during six months' treatment, and was associated with a significant decrease in cryocrit and a returning to normal of the lymphocyte CD4/CD8 ratio (in eight of nine patients). No significant variations were seen during the six month period without interferon. Only six patients withdrew from treatment, three because of side effects and three because of poor compliance.

Cryoglobulinemia↗