Dental vacuum system with skirt technology

A heat-sterilizable vacuum system (Legend) featuring a skirt technology that confines the user's hand to the sterile instruments during initial hose coupling and during patient treatment is described. Because the user does not grasp the non-sterile vacuum hose connector and hose, plastic barriers and mandatory disinfection of the hose connector, hose, and instrument holders after each patient are not necessary. The vacuum system described promotes asepsis by using sterile vacuum instruments, encourages sound asepsis practice, prevents cross-contamination, and is cost-effective.

Expression of the erythrocyte antigen Henshaw (He; MNS6): serological and immunochemical studies

Production of murine monoclonal antibodies to the low prevalence MNS antigen Henshaw (He; MNS6) has enabled more detailed study of this antigen. Using these directly hemagglutinating anti-He, red blood cells (RBCs) from 1695 people of African origin were screened in the USA and England. The prevalence of He+ samples among these donors was 2.1%. In Natal, blood samples from 1218 black donors were screened with rabbit anti-He. The prevalence of He+ donors in this population was 7.0%. Immunoblotting confirmed that the He antigen is carried on an erythrocyte membrane component with a molecular mass that is indistinguishable from glycophorin B. Hemagglutination and immunoblotting demonstrated that ten of 56 He+ samples tested more extensively had a reduced expression of the He antigen. The majority of He+ RBCs were S+; those He+ RBC samples that were S-s+ more frequently had a weakened expression of He.

[Evaluation of segregation ratio and hereditability of esophageal cancer--a comparative epidemiologic study in Huai'an County]

A genetic epidemiologic case-control study including 407 pedigrees (249 cases and 158 controls) was carried out to estimate the segregation ratio and the hereditability (h2) of esophageal cancer by using the method of Li-Mantel-Gart and Falconer, respectively, and to compare the genetic epidemiologic features from the other cancers. The results showed that the segregation ratio of esophageal cancer was 0.1347, significantly less than 0.25 and the genetic model belonged to polygenetics. The h2 of esophageal cancer was 21.41%, 20.23% for female and 13.57% for male. It is concluded that genetic factor is one of the risk factors for esophageal cancer and specially of importance for female, but it is not a main risk factor for esophageal cancer. The results of comparative epidemiologic study among the cancers of lung, stomach, liver and large bowel showed that the segregation ratios of the cancers (except stomach, no data) were all less than 0.25, and the h2 of gastric and liver cancers were higher, which were 52.40% and 51.85%, respectively.

Exon skipping by overexpression of a Drosophila heterogeneous nuclear ribonucleoprotein in vivo

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are abundant RNA-binding proteins that are implicated in splicing regulation. Here we investigate the role of a Drosophila hnRNP in splicing regulation in living animals. We find that overexpression of the Drosophila hnRNP HRB98DE leads to skipping of all internal exons in the Drosophila dopa decarboxylase (Ddc) pre-mRNA in vivo. These results indicate that HRB98DE has a splicing activity that promotes use of terminal splice sites. The effect of excess HRB98DE on Ddc splicing is transient, even though high levels of HRB98DE persist for at least 24 hr. This suggests that Drosophila larvae can induce a compensating mechanism to counteract the effects of excess HRB98DE.

SCN5A mutations associated with an inherited cardiac arrhythmia, long QT syndrome

Long QT syndrome (LQT) is an inherited disorder that causes sudden death from cardiac arrhythmias, specifically torsade de pointes and ventricular fibrillation. We previously mapped three LQT loci: LQT1 on chromosome 11p15.5, LQT2 on 7q35-36, and LQT3 on 3p21-24. Here we report genetic linkage between LQT3 and polymorphisms within SCN5A, the cardiac sodium channel gene. Single strand conformation polymorphism and DNA sequence analyses reveal identical intragenic deletions of SCN5A in affected members of two unrelated LQT families. The deleted sequences reside in a region that is important for channel inactivation. These data suggest that mutations in SCN5A cause chromosome 3-linked LQT and indicate a likely cellular mechanism for this disorder.

Relationship between colonial morphology and adherence of Streptococcus pneumoniae

Phase variants in colonial opacity of pneumococci differ in the ability to colonize the nasopharynx of infant rats. To explain this observation at a cellular level, we compared the ability of opacity variants to adhere to buccal epithelial cells, type II pneumocytes, or vascular endothelial cells and to the glycoconjugates that represent the cognate receptors at each of these sites. The transparent phenotype was associated with enhanced adherence to buccal cells (approximately 100%) and their receptor relative to that of the opaque variants. Only modest differences in adherence (< 45%) were demonstrated to resting lung and vascular cells. In contrast, adherence of transparent variants increased by 90% to lung cells stimulated with interleukin-1 and by 130% to endothelial cells stimulated with tumor necrosis factor. In contrast, cytokine stimulation did not influence the adherence of opaque pneumococci. This difference correlated with the unique ability of transparent variants to adhere to immobilized GlcNAc and to cells bearing transfected platelet-activating factor receptors. These results suggest that the mechanism of enhanced colonization of the nasopharynx in vivo by transparent as compared with opaque phase variants involves a greater ability to adhere to both GlcNAc beta 1-3Gal on buccal epithelial cells and GlcNAc and PAF receptors on cytokine-activated, as opposed to resting, lung and endovascular cells.

Binding of phosphorus-containing inhibitors to thermolysin studied by the Poisson-Boltzmann method

Zinc endopeptidase thermolysin can be inhibited by a series of phosphorus-containing peptide analogues, Cbz-Gly-psi (PO2)-X-Leu-Y-R (ZGp(X)L(y)R), where X = NH, O, or CH2; Y = NH or O; R = Leu, Ala, Gly, Phe, H, or CH3. The affinity correlation as well as an X-ray crystallography study suggest that these inhibitors bind to thermolysin in an identical mode. In this work, we calculate the electrostatic binding free energies for a series of 13 phosphorus-containing inhibitors with modifications at X, Y, and R moieties using finite difference solution to the Poisson-Boltzmann equation. A method has been developed to include the solvation entropy changes due to binding different ligands to a macromolecule. We demonstrate that the electrostatic energy and empirically derived solvation entropy can account for most of the binding energy differences in this series. By analyzing the binding contribution from individual residues, we show that the energy of a hydrogen bond is not confined to the donor and acceptor. In particular, the positive charges on Zn and Arg 203, which are not the acceptors, contribute significantly to the hydrogen bonds between two amides of ZGpLL and the thermolysin.

Conservative and nonconservative mutations in proteins: anomalous mutations in a transport receptor analyzed by free energy and quantum chemical calculations

Experimental studies on a bacterial sulfate receptor have indicated anomalous relative binding affinities for the mutations Ser130-->Cys,Ser130-->Gly, and Ser130-->Ala. The loss of affinity for sulfate in the former mutation was previously attributed to a greater steric effect on the part of the Cys side chain relative to the Ser side chain, whereas the relatively small loss of binding affinity for the latter two mutations was attributed to the loss of a single hydrogen bond. In this report we present quantum chemical and statistical thermodynamic studies of these mutations. Qualitative results from these studies indicate that for the Ser130-->Cys mutation the large decrease in binding affinity is in part caused by steric effects, but also significantly by the differential work required to polarize the Cys thiol group relative to the Ser hydroxyl group. The Gly mutant cobinds a water molecule in the same location as the Ser side chain resulting in a relatively small decrease in binding affinity. Results for the Ala mutant are in disagreement with experimental results but are likely to be limited by insufficient sampling of configuration space due to physical constraints applied during the simulation.

[Patella resurfacing and patellofemoral resurfacing]

Since 1983 isolated polyethylene patellar prosthesis was used for patella resurfacing of 19 patients with patellofemoral osteoarthritis. After an average of 44.9 months follow-up, the treatment was found to be not as satisfactory as earlier trials. The main reason was the wide erosion of femoral condyle caused by the polyethylene patella. To overcome this shortness, a new type of patellofemoral prosthesis was designed by the authors, which was named Y-L-Q. From January, 1991 to November, 1993, this prosthesis was used to treat 16 knees of 13 patients with patellofemoral osteoarthritis. Most of those patients improved both symptomatically and functionally. The good to excellent results rate was 87.5% (14/16 knees) at the time of an average 10 month follow-up. The early results of our experience with patellofemoral resurfacing are encouraging, and extended follow-ups are in progress.

Adherence status regulates the primary cellular activation responses to the flavivirus West Nile

Increases in cell-surface intercellular adhesion molecule-1 (ICAM-1; CD54) and major histocompatibility complex antigen class I (MHC-I) and class II (MHC-II) expression during flavivirus infection of murine macrophages was strongly dependent on adherence status. CD54 and MHC expression was significantly increased during infection with the flavivirus West Nile (WNV) on adherent, but not on non-adherent, macrophages. In contrast, increased CD54 and MHC-I expression was induced by interferon-gamma (IFN-gamma) in both cultures but was significantly greater on adherent cells than non-adherent cells. Adherent status was also important in human embryonic fibroblasts (HEF), adherent cells of non-immune origin. Similar to macrophages, WNV induced increased CD54 or MHC-I expression on adherent but not non-adherent HEF. Again, induction of these antigens by IFN-gamma occurred in both cultures but was significantly greater on adherent cells than non-adherent cells. Macrophages or HEF that aggregated when cultured at high density under non-adherent conditions, responded to WNV and IFN-gamma in a manner similar to adherent cells. Unresponsive non-adherent cells infected with WNV or treated with IFN-gamma under non-adherent conditions for 24 or 48 hr recovered if transferred to adherent culture conditions for 24 or 48 hr. Moreover, these cells expressed significantly higher cell-surface CD54 and MHC-I concentrations, compared to similarly treated HEF cultured under adherent conditions during the entire culture period. WNV infection also induced significant nitric oxide production in macrophages, and adherence status was similarly important in this response, with adherent cells producing higher amounts of nitrite/nitrate than non-adherent cells. These results suggest that adherent status may be critical for effective antiviral immune responses involving macrophages.

Hypercapnic acidosis and dimethyl amiloride reduce reperfusion induced cell death in ischaemic ventricular myocardium

OBJECTIVE

The aim was to investigate the effects of slowing the recovery of ischaemia induced intracellular acidosis with hypercapnic acidosis or dimethyl amiloride (DMA) on the extent of reperfusion induced cell death.

METHODS

Isolated arterially perfused rabbit papillary muscles and septa were suspended in a controlled atmosphere and perfused with a modified Tyrode solution containing erythrocytes and trypan blue (500 microM). Ischaemia was produced by arrest of perfusion and withdrawal of atmospheric O2. Extracellular pH of the muscle during reperfusion was controlled by adjusting the pH of the perfusate (pH 6.6 or pH 7.6 with and without DMA 20 microM) and changing the PCO2 of the chamber atmosphere. After 30 min of reperfusion following 30 min (group A) or 60 min (group B) of ischaemia, papillary muscles were fixed with paraformaldehyde. Cell death was assessed by trypan blue staining of nuclei in histological sections of the papillary muscles.

RESULTS

The magnitude of cell death was greatest after reperfusion with pH 7.6 as measured by the percentage of nuclei staining with trypan blue (15.1% in group A; 41.8% in group B). By contrast, reperfusion at pH 6.6 reduced cell killing (group A, 3.6%; group B, 7.2%). Reperfusion at pH 7.6 with DMA (20 microM) also reduced trypan blue uptake (group A, 2.8%; group B, 3.8%). Despite the attenuation of cell death afforded by acidosis or Na+/H+ exchange inhibition, significant swelling of the extracellular space and microvascular injury was noted.

CONCLUSIONS

Hypercapnic acidosis and Na+/H+ exchange inhibition during reperfusion attenuate lethal reperfusion injury to ventricular myocardium and extend to the intact myocardium the concept of the "pH paradox" in which recovery of intracellular pH after reperfusion is a precipitating factor in lethal cell injury.

Immunolocalization of cellular fibronectins in the normal liver, cirrhosis, and hepatocellular carcinoma

Cellular (c) fibronectins (Fn) differ biochemically, immunologically, and functionally from plasma fibronectins (pFn). Most existing data on Fn distribution in the normal and diseased liver require revision because those studies were based on reagents that did not distinguish pFn from cFn and predated the development of specific cFn monoclonal antibodies (Mabs). We immunostained cryosections of normal adult livers (n = 5), cirrhotic livers (n = 20), and livers with hepatocellular carcinoma (HCC) (n = 10) by the avidin-biotin-complex method with specific Mabs to the extradomains A and B (EDA, EDB) and oncofetal (Onc) isoforms of cFn. Selected samples were stained with an antiserum to pFn; fetal livers served as controls. Normal and cirrhotic livers showed EDA-cFn staining in the portal, septal, and perisinusoidal matrix; its distribution was more restricted than that of pFn. In cirrhosis, EDA-cFn reactions were strongest at sites of piecemeal necrosis and around proliferating ductules in biliary cirrhosis. EDA-cFn reactions were consistently most intense in the matrix of HCC. Distinct from adult normal and cirrhotic livers, reactions for EDB- and Onc-cFn were noted exclusively in most cases of HCC. We conclude that the only cFn isoform indigenous to the normal adult liver matrix is EDA-cFn. Enhanced EDA-cFn in cirrhotic livers may serve as indicator of active stromal remodeling. The restriction of EDB- and Onc-cFn to a large subset of HCC and the putative role of cFn in modulating cell-matrix adhesive interactions would suggest that the emergence of these molecules may be related to the variably invasive and metastatic properties of these tumors.

Prognosis of patients > or = 70 years of age with non-Q-wave acute myocardial infarction compared with younger patients with similar infarcts and with patients > or = 70 years of age with Q-wave acute myocardial infarction

In this study, 70 patients > or = 70 years of age admitted to the coronary care unit with non-Q-wave acute myocardial infarction (AMI) were followed prospectively for 1 year, and the clinical course in these patients was compared with that in 61 patients < 70 years with non-Q-wave AMI and 56 patients > or = 70 years with Q-wave AMI. Compared with the younger patients with non-Q-wave AMI, older patients were more likely to develop atrial fibrillation (23% vs 8%; p < 0.05) and congestive heart failure (53% vs 30%; p < 0.01), and less likely to receive thrombolytic therapy (9% vs 28%; p < 0.01), cardiac catheterization (41% vs 72%; p < 0.01), and coronary angioplasty (20% vs 39%; p < 0.05). Hospital mortality did not differ significantly between older and younger non-Q-wave AMI patients (10% vs 3%), but 1-year mortality was higher in the elderly (36% vs 16%; p = 0.02). Elderly patients with Q-wave AMI had more in-hospital complications, including death (25% vs 10%; p < 0.05), than elderly patients with non-Q-wave AMI. In contrast, postdischarge mortality was higher in elderly patients with non-Q-wave AMI, so that total mortality at 1 year was similar in the 2 groups. Overall, elderly patients with non-Q-wave AMI accounted for 62% of all deaths occurring during the first year after discharge (relative risk 2.6 compared with other groups; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Rural development and rural to urban migration in China 1978-1990

"Economic reforms since the late 1970s have brought about significant changes in rural China. A large number of surplus rural labourers have been released from the agricultural sector and there has been a massive transition of rural residents from agricultural to non-agricultural employment. These changes will be analyzed by examining the changes in the employment structure of rural residents.... It is found that town and country populations tended to move to towns at the intra-provincial level, but to cities at the interprovincial level. Out-migrants from cities tended to move to cities at both the intra- and inter-provincial levels."

Cell dissociation with papain reduces the density of cGMP-activated channels of the retinal rod

A proteolytic enzyme, papain, is the enzyme commonly used for dissociation of retinal neurons. To ask whether papain modifies the activity of ion channels, cGMP-activated channels were recorded in inside-out membrane patches excised from the bullfrog rod outer segment, and the activity was compared between cells dissociated using papain and cells dissociated mechanically. While the affinity to cGMP, I-V relation, channel kinetics, and single-channel current amplitude were almost the same in both papain-treated and the control preparations, the total current flowing through the patch membrane of the papain-treated cells was reduced to about 20% of the control, suggesting that papain reduced the density of cGMP-activated channels.

In vitro synergism of concentrated Allium sativum extract and amphotericin B against Cryptococcus neoformans

Allium sativum (garlic) derived preparations are used alone or with amphotericin B in Asia to treat human systemic fungal infections and cryptococcal meningitis. To evaluate the scientific merit of using allicin-derived compounds as an anti-fungal drug, we prepared a concentrated A. sativum extract that contained 34% allicin, 44% total thiosulfinates, and 20% vinyldithiins. We found that the concentrated extract possessed potent in vitro fungistatic and fungicidal activity against 3 different isolates of Cryptococcus neoformans. The minimum inhibitory concentration of the concentrated garlic extract against 1 x 10(5) organisms of C. neoformans ranged from 6 to 12 micrograms/ml. In addition, in vitro synergistic fungistatic activity with amphotericin B was demonstrated against all isolates of C. neoformans. This study lends laboratory support for the treatment of cryptococcal infections with concentrated garlic extracts.

Patella and patellofemoral resurfacing (37 cases report)

Chondromalacia and patellofemoral osteoarthritis are common diseases that cause pain and disablement of the knee. Conservative therapy is not always effective. Since 1983 we have used isolated polyethylene patellar prosthesis for patella resurfacing of 19 patients with patellofemoral osteoarthritis. After an average of 44.9 months follow-up, we found the treatment was not as satisfactory as earlier trials. The main reason is the wide erosion of femoral condyle caused by the polyethylene patella. To overcome this shortness, we designed a new type of patellofemoral prosthesis which is named Y-L-Q. From January, 1991 to November, 1993, we used this prosthesis to treat 16 knees of 13 patients with patellofemoral osteoarthritis. Most of those patients improved both symptomatically and functionally. The good to excellent results rate was 87.5% (14/16 knees) at the time of an average 16 months follow-up. The early results of our experience with patellofemoral resurfacing are encouraging, and extended follow-ups are in progress.

Marked activation delay caused by ischemia initiated after regional K+ elevation in in situ pig hearts

BACKGROUND

Conduction mediated by the slow inward (Ca2+) current occurs in vitro under specific experimental conditions but has not been documented in ventricular muscle in vivo during regional myocardial ischemia, perhaps because certain constituents of ischemia (including hypoxia and acidosis) may inhibit the Ca2+ current in this setting. We hypothesized that slow conduction mediated by the Ca2+ current could occur during acute ischemia in situations in which the extracellular K+ rise was more marked relative to the degree of acidosis, as may occur at ischemic boundaries.

METHODS AND RESULTS

In open-chest, anesthetized swine, an arterial shunt from the carotid artery to the mid-left anterior descending coronary artery was created through which a solution of KCl was infused to raise extracellular K+ ([K+]e) to approximately 9.4 mmol/L before the initiation of ischemia, which we termed "K(+)-modified ischemia." Ischemia initiated at a normal [K+]e ("unmodified ischemia") resulted in a mean activation delay in the center of the ischemic zone of 55 +/- 26 milliseconds after 5 minutes of ischemia and a decrease in epicardial longitudinal conduction velocity from 53 to 21 cm/s before the onset of conduction block. K(+)-modified ischemia resulted in a mean activation delay in the center of the ischemic zone of 181 +/- 8 milliseconds and a decrease in epicardial longitudinal conduction to less than 10 cm/s. K(+)-modified ischemia was associated with ventricular fibrillation in 85% of episodes compared with 28% of episodes of unmodified ischemia (P < .01). Verapamil prevented the occurrence of marked activation delay during K(+)-modified ischemia, producing local activation block following a maximum activation delay of 74 +/- 25 milliseconds. In two experiments, responses mediated by the slow inward current were produced by regional K+ elevation to 15 to 16 mmol/L, followed by concomitant regional administration of epinephrine (10(-7) mol/L). Regional [K+]e elevation alone to this level resulted in local activation block following a maximum activity delay of 70 to 80 milliseconds, whereas administration of epinephrine in combination with high [K+]e resulted in return of local activation with an activation delay of 160 to 180 milliseconds (ie, similar to that during K(+)-modified ischemia).

CONCLUSIONS

Compared with unmodified ischemia, K(+)-modified ischemia resulted in marked activation delay and a high incidence of ventricular fibrillation. Based on measurements of longitudinal conduction velocity, the inhibitory effect of verapamil, and the results of experiments with high [K+]e plus epinephrine, we conclude that the marked activation delay during K(+)-modified ischemia represents conduction mediated by the slow inward current. Because the conditions produced by K(+)-modified ischemia (high [K+]e with minimal acidosis) are similar to conditions in and near ischemic border regions, we hypothesize that responses mediated by the slow inward current may occur in such regions during unmodified ischemia and may participate in the development of reentrant arrhythmias.

Influence of iron deficiency on serum IgG subclass and pneumococcal polysaccharides specific IgG subclass antibodies

The serum IgG subclass concentrations in 47 cases and specific IgG subclass antibodies against pneumococcal polysaccharides (PnPs) were measured in 18 cases with iron deficiency. IgG subclass deficiencies were found in 28 (59.6%) cases with the frequency in order as IgG4 (27.7%, 13/47), IgG1 (21.3%, 10/47), IgG3 (14.9%, 7/47), and IgG2 (2.1%, 1/47). Compared with age-matched healthy children, the mean concentration of serum IgG4 and IgG1, and PnPs specific IgG1, IgG2 antibodies were decreased in children with iron deficiency. Decreased CD4+ cells and CD4+/CD8+ ratio in peripheral blood, low interleukin-6 (IL-6) activity, reduced lymphocyte proliferative responsiveness and increased recurrent respiratory tract infections (RRTI) were found in iron deficiency children. These results suggested that serum IgG subclass and PnPs specific IgG subclass antibody deficiencies caused by dysfunction of the regulation of T lymphocyte on B lymphocyte may be related to the susceptibility to RRTI in children with iron deficiency.

cis-regulatory sequences responsible for alternative splicing of the Drosophila dopa decarboxylase gene

The Drosophila dopa decarboxylase gene, Ddc, is expressed in the hypoderm and in specific sets of cells in the central nervous system (CNS). The unique Ddc primary transcript is alternatively spliced in these two tissues. The Ddc CNS mRNA contains all four exons (A through D), whereas the hypodermal mRNA contains only three exons (A, C, and D). To localize cis-regulatory sequences responsible for Ddc alternative splicing, a Ddc minigene and several fusion genes containing various amounts of Ddc sequences fused to fushi tarazu (ftz) exon 1 were constructed and introduced into flies by P-element-mediated germ line transformation. We find that Ddc intron ab and exon B are sufficient to regulate Ddc alternative splicing, since transcripts of a minimal fusion gene containing most of Ddc intron ab and exon B are spliced to exon B in the CNS but not in the hypoderm. These results indicate that Ddc alternative splicing is regulated by either a negative mechanism preventing splicing to exon B in the hypoderm or a positive mechanism activating splicing to exon B in the CNS. Our previous data suggest that Ddc hypodermal splicing is the actively regulated splicing pathway (J. Shen, C. J. Beall, and J. Hirsh, Mol. Cell. Biol. 13:4549-4555, 1993). Here we show that deletion of Ddc intron ab sequences selectively disrupts hypodermal splicing specificity. These results support a model in which Ddc alternative splicing is negatively regulated by a blockage mechanism preventing splicing to exon B in the hypoderm.

[Modified en bloc resection procedure for malignant tumor of the shoulder girdle]

En bloc resection of the shoulder girdle (Tikhoff-Linberg procedure) is a valuable limb-sparing surgical technique for bony and soft tissue malignant tumor in and around the proximal humerus and shoulder girdle. Significant amount of hand-elbow function is maintained with the procedure, and long time results in the treatment of neoplasms by this technique was found to be the same as by the method of a forequarter amputation or the shoulder disarticulation in the English literature. Four cases with malignant tumor in the shoulder girdle was treated with this modified method in our department. The average follow-up was 8 years. One case died due to another kind of tumor 6 years after operation, and other 3 cases are alive and disease free.

Application of internal fixation in the treatment for tuberculosis of the spine

This is a study of 18 patients who had surgical treatment for spinal tuberculosis. All patients were admitted with the spinal tuberculosis and treated with a combination of anterior debridement and bone graft with posterior internal fixation using the Luque or Dick technique. The patients were able to walk within a few days postoperation. Three to seven years follow-ups show no recurrence, kyphosis and/or solid fusion.

[Long-term follow-up of patients with patella resurfacing]

Patellar resurfacing was performed by the authors. From 1983 to 1988, 19 cases (22 knees) with patello-femoral osteoarthritis were treated with this procedure in our hospital. Excellent and good results were recorded in 13 cases (59.1%) one year after operation, but were zero in the long-term follow-up (average 8.7 years) because of recurrent knee pain due to the wearing of the cortex of the femoral groove. Further operation was necessary for those cases, such as patellectomy or total knee replacement. Since 1991 Y-L-Q's type of patellofemoral replacement has been used in 11 cases in our department to alter the isolated resurfacing of the patella. The femoral groove was replaced with a metallic implant that allows sliding of a polyethylene patella to prevent the wearing of the femoral cortex. Preliminary results are good.