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L Barba

Publications and source records attributed to L Barba.

At least 19 recordsLinked to original sources
PubMed2003

Recurrent and de novo diabetic nephropathy in renal allografts.

BACKGROUND: Histologic findings of diabetic nephropathy (DN) are observed in allografts of patients with pretransplant (PreTx) diabetes mellitus (DM) and in patients who develop DM posttransplant (PostTx). Patients with allograft biopsies (Bx) were retrospectively studied to determine the incidence of recurrent and de novo DN and to ascertain what, if any, risk factors predispose to histologic DN in either patient population. METHODS: From the renal transplant services at four hospitals from 1992 to 2000, the authors identified all patients with PreTxDM and PostTxDM (n=81). Those with renal biopsies performed >/=18 months PostTx were classified according to the presence or absence of histologic DN (Bx-positive, n=23; Bx-negative, n=35). Patients were then subdivided into four categories-recurrent DN (n=16), de novo DN (n=7), no recurrent DN (n=27), and no de novo DN (n=8)-for analyses. RESULTS: Among these 58 patients, 74.1% had PreTx and 25.9% had PostTx diabetes. Of those with histologic DN, 69.6% were recurrent DN and 30.4% were de novo DN, making de novo DN at least as likely to develop as recurrent DN. After the onset of diabetes in the de novo population, the time to development of histologic DN was similar in the recurrent and the de novo patients (6.68+/-3.86 years vs. 5.90+/-3.13 years, P=0.66) and more rapid than previously reported. Apart from a more frequent family history of hypertension in patients with allograft DN compared with those without allograft DN, known risk factors for the development of native DN did not significantly differ among patients in the four cohorts. Proposed risk factors related to transplantation did not correlate with the development of recurrent or de novo DN. CONCLUSION: Among patients with histologic DN, de novo DN occurred at least as frequently as recurrent DN, and the time to onset of histologically apparent DN was more rapid than previously reported. Neither the usual clinical predictors of DN nor clinical variables related to transplantation clearly distinguished the group with DN from the group without it, potentially implicating novel mechanisms in its pathogenesis.

Adult↗
PubMed2002

Analysis and toxicity of methomyl and ametryn after biodegradation.

The controlled biodegradation of ametryn and methomyl has been performed, in accordance with the OECD Zahn-Wellens/EMPA procedure, by use of an enriched mixture of activated sludge collected from three domestic waste-water-treatment plants (WWTP). During the process concentrations of ametryn and methomyl in the water samples were isolated by solid-phase extraction (SPE); recovery rates were 98.9 and 93.2 for methomyl and ametryn, respectively. Liquid chromatography-mass spectrometry (LC-MS) was used to determine final pesticide concentrations and for metabolite identification. The efficiency of aerobic biodegradation of ametryn and methomyl was evaluated by measuring both the decrease in the concentration of the pesticides and global properties such as the chemical oxygen demand (COD). The acute toxicity of ametryn and methomyl was evaluated by use of the ToxAlert100 biological test, which is based on inhibition of the bioluminescence of Vibrio fischeri. There was significant correlation between results from primary and ultimate biodegradation and those from determination of toxicity. Pesticide concentrations were always reduced to below the limit of detection in less than 17 days. High COD removal (90-96%) was achieved in 28 and 18 days for methomyl and ametryn, respectively.

Biodegradation, Environmental↗
PubMed2001

Glomerular mRNAs in human type 1 diabetes: biochemical evidence for microalbuminuria as a manifestation of diabetic nephropathy.

BACKGROUND: In patients with type 1 diabetes, some consider microalbuminuria to be a predictor of diabetic nephropathy while others believe it is an early feature of diabetic nephropathy. METHODS: Levels of mRNAs that are of pathogenetic relevance in diabetic nephropathy were compared in glomeruli isolated from microalbuminuric and overtly proteinuric subjects and in control normoalbuminuric diabetic subjects and living renal transplant donors. RESULTS: In subjects with microalbuminuria and overt proteinuria, glomerular mRNAs were virtually identical and approximately twofold higher for connective tissue growth factor (CTGF; P < 0.01) and collagen alpha2(IV) (P < 0.03) compared to living renal donors and normoalbuminuric patients. Glomerular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) levels were not significantly different among the groups (P = 0.4). Weak but statistically significant correlations were noted between CTGF mRNA and albuminuria (assessed by rank), fractional mesangial surface area, and a composite renal biopsy index. Glomerular CTGF mRNA correlated inversely with creatinine clearance. Glomerular collagen alpha2(IV) mRNA levels correlated with albuminuria (by rank) and less strongly with fractional mesangial area. CONCLUSION: To our knowledge, these data provide the first biochemical evidence demonstrating that the glomeruli of microalbuminuric patients and those with overt proteinuria do not differ significantly. The data support the concept that microalbuminuria is not "predictive" of diabetic nephropathy, but rather is an earlier point in the spectrum of diabetic nephropathy.

Adult↗
PubMed2001

[Single-compartment knee arthroplasty prosthesis and idiopathic necrosis of the medial tibia surface].

PURPOSE OF THE STUDY: Idiopathic necrosis of the medial articular surface of the tibia is exceptional. Diagnosis is quite difficult and often made late. Among the different treatments proposed, we preferred single-compartment arthroplasty. MATERIAL AND METHODS: We report 8 cases in women with a mean age of 71.1 years. Diagnosis was suspected due to drug-resistant knee pain, particularly frequent at night, initially with radiographically normal knees. The first radiographic signs, seen 3 months after the onset of pain, were pathognomonic for osteonecrosis evidencing subchondral defects of the tibial surface with a dense peripheral rim and apparently "sequestered" in a notch. Bone scintigraphy evidenced intense uptake in the medial compartment. MRI confirmed the diagnosis evidencing a band of low intensity signals completely surrounding a sequestered zone reaching the cortical. This band was stable and irreversible. In 5 cases CT scan and in 3 cases tomography identified the width and height of the necrotic area that was limited to the medial compartment in all cases. All patients were treated with a single compartment implant. The diagnosis of necrosis was confirmed at pathology. RESULTS: At 4,6 years of mean follow up all patients had an excellent outcome, "forgetting" their knee. No lucent lines developed along the femoral or tibial implants. DISCUSSION: Necrosis of the medial articular surface of the tibia is exceptional and often diagnosed late by bone scintigraphy or MRI. Surgical treatment is usually based on tibial osteotomy for valgisation or a single or three-compartment prosthesis. In our 8 cases, the necrosis was limited to the medial compartment, warranting our therapeutic option.

Aged↗
PubMed2000

Glomerular type IV collagen in patients with diabetic nephropathy with and without additional glomerular disease.

BACKGROUND: Type IV collagen is a constituent of mesangial matrix and is increased in amount in many forms of glomerular injury. METHODS: We performed renal biopsies in patients who (1) were donating a kidney to a relative (LRD, N = 6), (2) had diabetic glomerulopathy with or without nephrosclerosis (DM, N = 6), or (3) had diabetic glomerulopathy with a superimposed glomerular lesion (DM+, N = 5). Glomerular collagen alpha2(IV) and control glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNAs were measured, and the former correlated with clinical and morphological data to assess its usefulness in reflecting glomerular injury. RESULTS: Collagen alpha2(IV) mRNA levels were lowest in LRD (2.9 +/- 0.6 attomol/glomerulus), higher in DM (5.9 +/- 1.6, P = 0.05), and highest in DM+ (12.7 +/- 2.8 attm/glomerulus, P < 0.05 vs. LRD and vs. DM). Control GAPDH mRNA levels were not significantly different (P > 0.05). Levels of proteinuria, serum creatinine, and glomerular size did not correlate with collagen alpha2(IV) mRNA levels. The fractional mesangial area and the fractional mesangial area occupied by type IV collagen were higher in both diabetic groups than in LRD (P < 10-6), but the intensity of type IV collagen staining in the diabetic patients was significantly less than that seen in the LRD (P < 0.01). In DM+ patients, extramesangial type IV collagen was present. Fractional mesangial area and glomerular collagen alpha2(IV) mRNA levels correlated (r = 0.45, P < 0.05). CONCLUSION: These data are consistent with a view of diabetic nephropathy as a lesion of increased alpha2 type IV collagen transcription, increased total amount of collagen present, but decreased mesangial density relative to other matrix molecules. These data further demonstrate that glomerular injury superimposed on diabetic nephropathy contributes to additional structural damage by inducing increased synthesis of type IV collagen at extramesangial sites.

Adult↗
PubMed2000

[Osteolysis after total knee prosthesis].

PURPOSE OF THE STUDY: The aim of our work was to study X-rays showing osteolysis after 5 years and more in 122 prosthesis and to try and assess such complication, often described in the United States but seldom in Europ. MATERIAL: We are dealing here with 122 retaining posterior cruciate ligament, mostly cementless prothesis implanted between 1985 and 1992 84 chromium-cobalt prosthesis (PCA and Themis) implanted in 34 males and 88 females with an average age of 67 (45-81), 87,7 p. 100 had femoral cementless components and 70 p. 100 tibial cementless components. METHODS: All patients were examined and had X-rays at an average of 6,9 years. Specially considered were X-rays showing a possible osteolysis. We looked for possible complication (external laxity, anterior femoral dislocation and polyethylene wear), assessment of the mechanical axis and for clinical results (Hungerford score) RESULTS: Revisions: 19 arthroplasties were revised for PE wear tibial loosening metallosis or patella problems The postoperative score according to Hungerford was 84,5 p. 100 for PCA prosthese and 87 p.100 for the Themis. On the X-rays were only few osteolysis to be found: 9 cases (7,3 p. 100). For the PCA series: 3 femoral osteolysis, 1 tibial at 12 years, and one patellar osteolysis. For the Themis series: no femoral osteolysis, 3 tibial and one patellar osteolysis. Osteolysis are apparent on X-rays in profile for the femur and the patella, and in both profile and frontal X-rays for the tibia. Clinicaly 4 osteolysis really asymptomatic were not re-operated. 5 were revised: one 11 years later for femoral and tibial loosening, two for a patellar loosening, the other two patients had to be reoperated on for metallism (titanium's femoral component) and for those two instances osteolysis were discovered during the complication. DISCUSSION: Osteolysis after TKA appears unusual in our experience without bearing on frequency finded by american authors with a lesser follow-up (Engh 11,1 p. 100 after 4,5y, Peters 16 p. 100 after 2,9 y, Robinson 9,18 p. 100 after 4,6 y). American litteratur analysis shows that the important number of osteolysis is due to: - either to dual-metal using (Co-Cr component with Titanium screws for exemple), - or bad quality of polyethylene (compressed), - or a bad design of former prosthesis. CONCLUSION: Interface illness, linked to the production of wear debris, osteolysis after total knee arthroplasty is rarer than after a hip one, probably because size of debris is different, larger in knee than in hip. It is likely that the improvement of PE quality, design of prosthesis, as well as a better knowledge of osteolysis mechanism will allow to delay this complication wich is in a long term ineluctable.

Aged↗
PubMed1999

Determination of the site of incorporation of cobalt in CoZnPO-CZP by multiple-wavelength anomalous-dispersion crystallography.

Data were collected from a crystal of CoZnPO-CZP {sodium cobalt-zinc phosphate hydrate, Na(6)[Co(0.2)Zn(0.8)PO(4)](6).6H(2)O} using synchrotron radiation at ELETTRA at the inflection point and 'white line' for both the cobalt and zinc K edges, and at 1.45 Å, a wavelength remote from the K edges of both metals. The data were processed using the programs DENZO and SCALEPACK. The CCP4 program suite was used for the scaling of data sets and the subsequent calculation of dispersive difference Fourier maps. Optimal scaling was achieved by using a subset of reflections with little or no contribution from the metal atoms (i.e. which were essentially wavelength independent in their intensities) and using weights based on the sigma's to obtain an overall scale factor in each case. Phases were calculated with SHELXL97 based on the refined structure using a much higher resolution and complete Cu Kalpha data set. An occupancy of 100% by zinc at the two metal-atom sites was assumed. The dispersive difference Fourier map calculated for zinc gave two peaks above the background of similar heights at the expected metal-atom sites. The peak height at the Zn1 site was a little higher than at the Zn2 site. The dispersive difference Fourier map calculated for cobalt gave just one peak above the background, at the Zn1 site, and only a small peak at the Zn2 site, thus indicating that incorporation of cobalt takes place mainly at one site. Refinement of the zinc occupancies using MLPHARE reinforces this conclusion. The chemical environment of each site is discussed.

Journal Article↗
PubMed1998

Structure of sulfur-substituted rhodanese at 1.36 A resolution.

1.36 A resolution X-ray diffraction data have been recorded at 100 K for bovine liver sulfur-substituted rhodanese, using synchrotron radiation. The crystal structure has been refined anisotropically to a final R factor of 0.159 (Rfree = 0.229) for 53034 unique reflections. The model contains 2327 protein atoms and 407 solvent molecules, with a good geometry. The high resolution allows full details for helices, beta-sheets, tight turns and of all inter- and intramolecular interactions stabilizing the enzyme molecule to be given. The situation at the active site is described, particularly in regard to the network of hydrogen bonds made by Sgamma and Sdelta of the sulfur-substituted catalytic Cys247 and surrounding groups and solvent molecules. The replacement of the precipitant ammonium sulfate with cryoprotectants in the crystal-suspending medium led to the removal of the sulfate ion from the enzyme active site. Only limited changes of the enzyme structure have been found as a result of the drastic change in the crystal medium.

Animals↗
PubMed1997

Improved survival of en bloc renal allografts from pediatric donors.

PURPOSE: We developed a technical and immunological protocol to increase survival of renal transplants from pediatric donors. MATERIALS AND METHODS: En bloc kidneys (22) were procured from donors weighing 2 to 14 kg. (1 to 60 months old) and transplanted into adult recipients. In group 1 (12 patients) sequential therapy was used for kidneys with more than 35 hours of cold storage and immediate triple therapy (cyclosporine, azathioprine and prednisone) was used for those with less than 35 hours of cold storage. In group 2 (10 patients) OKT3 induction therapy was used. Mean followup was 4.7 years. RESULTS: Mean blood pressure at 1 and 4 years was not significantly different between the groups. Mean serum creatinine was not significantly different between the groups at 1 year but it was significantly less in group 2 at 4 years (1.9 +/- 1.0 versus 1.2 +/- 0.24 mg./dl., p <0.05). At 1 year of followup the complication rate was 75% in 9 of 12 patients in group 1, including 4 infections or leaks (2 lost), 6 rejections (3 lost) and 3 cases of thrombosis or hemorrhage, and 20% (p <0.01) in group 2 (1 patient had the hemolytic uremic syndrome leading to graft loss). Graft survival was significantly greater in group 2 at all 4 years of followup (p = 0.05). CONCLUSIONS: The success of pediatric en bloc renal transplantation can be enhanced by induction therapy in healthy recipients.

Child, Preschool↗
PubMed1997

Patient death or renal graft loss within 3 yr of transplantation in a county hospital: importance of poor initial graft function.

Our purpose was to study the factors predictive of graft loss or patient death within 3 yr of renal transplant in a county population. 363 renal transplants performed between 1984 and 1991 at the Harbor-UCLA Medical Center were reviewed. There were 16 recipients (4%) who died and 76 (21%) who lost their grafts within 3 yr. Known causes of death were cardiac (44%), infection (38%) and malignancy (6%). There was a higher proportion of diabetics (44%), hypertensives (69%) and those with a past cardiac history (38%). There was also a high delayed graft function rate (56%). Of the 76 grafts that failed in the first 3 yr, 14% were due to noncompliance, 20% to grafts that never functioned, 9% to technical problems, 21% to acute rejection, 9% to recurrent disease and 26% to chronic rejection. The noncompliance group were younger (mean 34 yr), and more likely to be a first transplant (90%) and be non-white (82%). The rejection group was significant for high delayed graft function rate (84%) and frequent and early rejection (76% at least one rejection). We conclude that fair organ allocation requires a balance between equity and utility, but patient death or graft loss within 3 yr benefits neither the patient or society. Patient survival may be improved with diligent cardiac evaluation, particularly in older patients and diabetics. Patient education and monitoring for noncompliance is essential, particularly in young first-time recipients. Maneuvers to decrease delayed graft function are essential to improve long-term results.

Adolescent↗
PubMed1995

Interleukin-12 mRNA levels in renal allograft fine-needle aspirates do not correlate with acute transplant rejection.

TH1 cytokines, including gamma-interferon (IFN), are critical in the initiation and progression of allograft rejection. As interleukin (IL)-12 up-regulates gamma-IFN, we assessed the role of IL-12 in human transplant rejection. Twenty renal allograft fine-needle aspirates from 19 patients were obtained, evaluated in the standard fashion, and assessed for gamma-IFN and IL-12p40 subunit mRNA levels using nested reverse transcriptase polymerase chain reaction. Ten aspirates demonstrated acute rejection by clinical criteria, and 9 of the 10 aspirates contained gamma-IFN while only 3 demonstrated IL-12; there were no distinguishing characteristics for these 3 patients with regard to therapy, or time of onset and severity of rejection. Seven patients without clinical or morphologic rejection failed to demonstrate gamma-IFN or IL-12. Three patients had discrepant findings; there was no morphologic rejection, yet all 3 patients contained gamma-IFN and 1 patient demonstrated rejection on subsequent biopsy. However, only 1 aspirate exhibited IL-12 and this patient had no documented subsequent rejection. This study confirms the association of gamma-IFN mRNA with acute rejection. In contrast, IL-12 mRNA does not appear to play a key role early in the rejection process.

Acute Disease↗
PubMed1995

Intrarenal extramedullary erythropoiesis in renal allograft fine-needle aspirates.

Recombinant human erythropoietin (rhEPO) is widely used in patients with end-stage renal disease and occasionally in renal allograft recipients to correct anemia. Red blood cell production is markedly increased by rhEPO; however, no extramedullary erythropoiesis (EME) has been associated with this hormone. We observed intrarenal EME in five allograft fine-needle aspirates performed for reduced graft function in four patients between 3.7 and 7 weeks following transplantation. These four patients received rhEPO during dialysis and three resumed rhEPO therapy after transplantation; all four remained anemic. Donors were between 13 months and 13 years of age, with one pediatric and three adult recipients. Aspirates with apparently incidental EME contained all stages of red blood cell precursors, but these cells were not observed in corresponding peripheral blood samples. The hematopoietic cells could be readily distinguished from cells of lymphoid origin. There were no correlations between intragraft EME and aspirate or clinical diagnosis referable to renal dysfunction. Aspirates performed prior to 3.7 weeks or after 7 weeks did not demonstrate EME. These data suggest that endogenous EPO and rhEPO in anemic patients receiving pediatric renal allografts may activate red blood cell precursors in the young graft, inducing intrarenal EME. Recognition of this entity is important to distinguish it from immune activation or malignancy within the donor organ.

Adult↗
PubMed1995

Monitoring changes in cyclosporine dosage by trough level testing.

The concept of a narrow therapeutic window has guided the management of transplant recipients on cyclosporine immunosuppression since its inception more than a decade ago. The need to maintain immunosuppression and avoid toxicity imposed the requirement of monitoring cyclosporine levels within a limited range. The use of circulating trough levels to aid in the adjustment of dosage, however, has also led to controversies. Trough levels did not immediately reflect the dose, and circulating drug levels varied even in the absence of dose changes, indicating the role of factors other than the dose. By introducing a time factor or delay between the dose and trough levels, the sequential delay analysis allows a clearer demonstration of the relationship between doses and trough levels. Using dose adjustments as markers, corresponding changes in the trough levels were observed for most markers after a short delay. The existence of a time factor imposes some restrictions on the scheduling of dose changes and trough level tests. Adjustments in dose need to be separated to avoid interference from each other and the frequency of testing after a change increased to assure its detection. Consideration of the delay should aid in the adjustment of doses and provide an initial step in the understanding of other factors in the relationship between the dose and circulating trough levels.

Chromatography, High Pressure Liquid↗
PubMed1995

[Uncemented knee prosthesis. Results apropos of 58 cases with a minimum of 5-year follow-up].

PURPOSE OF THE STUDY: The aim of this study was to evaluate, after at least 5 year's follow-up, the results of 64 PCA (TM) cementless total knee prostheses. MATERIAL: From 1984 to 1988, 13 male and 45 female patients (a total of 64 prostheses including 6 bilateral) received PCA Primary prostheses. Both femoral and tibial components were implanted without cement. Mean age of patients was 68.9 years (range: 35-81); mean patient height was 164.41 cm and mean weight 76.74 Kg. The most frequent pathology was gonarthrosis: 43 cases of medial gonarthrosis and 15 of lateral gonarthrosis. There were 4 cases of rheumatoid arthritis and two post-traumatic degenerative arthritis. 52 knees were free of any previous surgical procedure. Of the 64 prostheses and the 58 patients: 6 died and 2 were lost to follow-up; 56 knees were reviewed. The longest follow-up is 9 years for an average of 6.8 years. METHODS: Prosthetic review included clinical evaluation (Hungerford score based on 100 points, ISK rate based on 200 points) and complete radiological evaluation enabling the postoperative position of the implants to be examined. Radiolucencies were examined according to Ewald. X-ray study of polyethylene wear was performed based on the distance between the prosthetic condyle to the height of the metal tibial plateau. All patients were operated on by the same surgeon using the same procedure, and the same postoperative outcome. RESULTS: There were no local postoperative complications or any early reoperations. PHlebitis occurred in 12 per cent of cases. With the exception of 8 patients who were reoperated due to mechanical complications, the Hungerford score raised from 37.5 preoperatively to 88.3 postoperatively. The results of 43 of the 48 patients were rated good or excellent. The 200 point score rating gave 91 per cent of good and excellent results for knee examination, and 69 per cent of good and excellent results for knee function. Mean flexion angle was 107.8 degrees mean pain scored 45/50. Radiologically 75 per cent of operated patients had postoperative varus or valgus in the range 0-5 degrees as against 24 per cent preoperatively. The study of edge defects revealed the absence of any radiological abnormality on the femoral lateral projection in 85 per cent of cases, and the absence of abnormality on the tibial anteroposterior and lateral projections in more than 60 per cent of cases. X-ray study of polyethylene wear was conducted on 49 cases: polyethylene wear was observed radiologically in 1 of 4 cases. There was no correlation between polyethylene wear and polyethylene thickness, postoperative axes, body weight or clinical results. 8 patients had to be reoperated due to mechanical complications: 2 because of a tilting tibial plateau (due to a technical fault), 4 because of polyethylene wear and 2 because of patellar loosening (uncemented metal-back patellar implant). DISCUSSION: The implantation of femoral and tibial components of cementless PCA Primary fitted seems very satisfactory. With longer follow-up, we noted no tibial or femoral osteolysis signs such as those described by Engh, Peters or Berry in the USA. Stability of mid term radiographical results was commonly observed throughout our study. Only 5 very slight lateral displacements were noted: 3 cases of secondary LCP insufficiency with tibial posterior subluxation; in 2 cases the cause was R.A. CONCLUSION: The implantation of uncemented PCA Primary prosthesis caused non complications with respect to the femur. Regarding the tibia, only two reoperations were required because of tibial fixation failure due to a technical fault. The use of a hybrid prosthesis is not required. The microbeads used in PCA are effective but current availability of other materials promoting better bone growth (such as hydroxyapatite, titanium mesh) allows safe implantation of uncemented prostheses. PCA Primary polyethylene wear seems to develop steadily. This is why it should be replaced by the less

Adult↗
PubMed1993

Los Angeles organ sharing: twenty-six-year report.

1. The Los Angeles Transplant Society and the Regional Organ Procurement Agency of Southern California (ROPA) was established in November 1967. ROPA was the first such organization in the United States. 2. The use of simple cold storage and shipment of kidneys by commercial airline resulted from pioneering concepts developed in the Los Angeles area from 1968-1969. 3. In the 26-year period of ROPA's operation, it has coordinated 8,446 kidney transplants. 4. All kidneys transplanted in 1993 were allocated according to the UNOS point system. 5. Allocating all kidneys under the point system has not significantly disadvantaged either large or small transplant centers in the greater Los Angeles area. 6. Racial distribution of recipients: 13% Black (compared with Los Angeles population of 12% and 6% donor population). Blacks represent 20% of the recipient waiting list. Hispanic recipients were 31% (compared to Los Angeles population of 40% and donor population of 30%). Hispanics comprised 28% of the waiting list. 7. The average waiting times for centers in the Los Angeles area ranged from 14-19.4 months. Transplanted patients waited an average of 16.3-22.1 months. 8. "Required request" had a significant effect on the number of referrals but did not produce a meaningful increase in the number of kidneys transplanted.

Cryopreservation↗
PubMed1993

[Reoperation after failure of unicompartmental knee prosthesis. Therapeutic strategy and results based on 40 cases].

Forty revisions for failure of unicompartmental knee prostheses were assessed. Twenty-eight women and twelve men (mean age: 67 years) were reoperated. Failure of an medial single-compartment prosthesis was involved in 35 cases, of a lateral prosthesis in 5 cases. The initial prostheses had been cemented in 19 cases and uncemented in 21 cases. Preoperative functional conditions were assessed by Hungerford's functional score and a 200-points score. The radiological study before revision showed 35 cases of varus distortion; in 12 of these, the varus distortion exceeded 10 degrees. Rather than studying the causes for failure of the single-compartment prosthesis, it seemed more useful to try to define the adequate reoperation procedure strategy and analyze its results. Our procedure aimed at solving the following difficulties: surgical approach: the same incision as in the initial operation was performed, the primary prosthesis was removed and a two-stage treatment was justified in cases of infection, metallosis involved complete removal of debris, the problem of bone-recutting and, chiefly, the problem of residual bone defect requiring bone-graft. Bone-recutting was performed with the tibial and femoral elements of the primary prosthesis still in place and using the ancillary equipment of the new prosthesis. Bone defects involved the femur as often (14 cases) as the tibia (12 cases); tibial bone defects occurred more frequently with cemented prostheses (9 cases) than with uncemented prostheses (3 cases). Femoral graft being relatively easier to perform one of the two major difficulties in our strategy was the achievement of a tibial graft.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Kidney allocation under the UNOS point system: an update.

1. The 1,480 patients awaiting cadaveric renal transplants at 14 Southern California transplant centers as of December 3, 1992, were compared with patients transplanted using a point system for one kidney and a hospital-based allocation for the second, or the current system allocating all locally procured kidneys by the point system with regard to several demographic parameters. 2. Of 1,472 waiting patients with sensitization data, 8.5% were broadly sensitized (> 80% PRA). Of the 737 kidneys allocated by the point system, 7% went to broadly sensitized patients, compared with 3% of 438 kidneys allocated by the hospitals (p < 0.001). 3. Of 1,470 waiting patients with information available, 23% were awaiting a repeat transplant. Under the point system, 18% of kidneys were used for repeat transplants compared with 9% of hospital-allocated kidneys (p < 0.001). 4. Of 1,434 waiting patients where the time waiting was available, 26% had waited 1-2 years, 12% 2-3 years, and 6% more than 3 years. Under the point system, patients waiting longer received significantly more kidneys than those recently added to the list: 35% had waited 1-2 years, 21% 2-3 years and 14% more than 3 years (p < 0.001). Kidneys allocated by the hospitals were transplanted to patients in approximately the same proportions as the waiting list: 29% to those waiting 1-2 years, 10% 2-3 years, and 3% more than 3 years. 5. Racial distribution of recipients was not significantly different under either allocation system from that of the waiting list. Whites comprised 39% of waiting patients, the same as the population of Los Angeles County.(ABSTRACT TRUNCATED AT 250 WORDS)

California↗