Radiographic comparison of diaphyseal grit blasted with smooth surface stems by matched pair analysis

A matched pair comparison of two groups of 42 patients who had a total hip arthroplasty with uncemented fixation of the femoral stem with proximal porous coating and distal grit blasting were compared with a stem of identical design except with diaphyseal smooth surfaces. Radiographic analysis was done to determine differences in fixation and bone remodeling at the 2-year followup, and these results were compared with clinical results. The method used for measuring cortical thickness was semiquantitative, with measurements done at 15 1-cm increments beginning at 3 cm distal to the midlesser trochanter. This study determined whether, with an identical stem design, diaphyseal biologic fixation, rather than mechanical fixation, would provide better fixation without significant stress shielding differences. Seven percent of grit blasted stems had radiolucent lines in Gruen Zones 3 to 5, compared with 79% of smooth stems. The smooth stem was on average one size larger so the stress shielding was not different between matched pairs. There was a distinct pattern of adaptive remodeling that occurred in the femur with both stem surfaces. Bone loss was greatest in the proximal medial and proximal posterior bone and occurred along the entire anterior cortex. Bone thickening occurred in the distal medial and posterior cortices and extended below the tip of the prosthesis.

Radiographic anatomic structure of the arthritic acetabulum and its influence on total hip arthroplasty

Acetabular bone structure is not the same in all patients and can be defined by the radiolucent triangle superior to the acetabulum. Of 132 hips, 81 had an isosceles triangular shape, which was named type A acetabulum. Forty-six hips had an extension of the triangle into the teardrop, which created a thickened medial wall and was named type B. Five hips had a right-angle triangle, which was found only with congenital disease of the hip and was named type C. The density of the superior acetabular bone in the triangle could be normally radiolucent (stage I), have vertical and transverse trabeculae throughout the triangle (stage II), or have the triangle filled with bone and cysts (stage III). The relationship between progressive radiolucent lines and acetabular type showed that type A3 (thin medial wall with dense triangle bone) had the highest incidence of progressive radiolucent lines (P < .05).

The effect of diaphyseal biologic fixation on clinical results and fixation of the APR-II stem

This study evaluated the effect of a grit-blasted diaphyseal surface on noncemented fixation of the Anatomic Porous Replacement II stem (APR-II, Sulzer Medica Orthopaedics, Austin, TX) for improvement of clinical results and fixation. A total of 107 consecutive total hip arthroplasties with the APR-II stem, which has proximal porous coating and a diaphyseal grit-blasted surface, were performed without cement, and 99 were studied at average 4 years. Of these hips, 37 had hydroxyapatite sprayed onto the proximal porous coating, but because there were no statistical differences for performance in any category, all stems were considered as 1 group. Clinical results were measured by the Harris hip score. Radiographic measurements of fixation, osteolysis, and bone remodeling were studied by reference to Gruen zones. Of hips, 99% had a good or excellent result by Harris hip score, with an average pain score of 42.3. Of hips, 98% had >40 points, with no patient reporting thigh pain after 3 years. There were no radiolucent lines in 94% of stems, and 100% had proximal bone ingrowth fixation. Distal cortical hypertrophy associated with tip fixation occurred in 49%, whereas proximal stress shielding was present in 43% of hips. Comparison of these clinical and radiographic results with our previous experience of bone ingrowth implants (smooth stem) suggests that bone ingrowth proximally with ongrowth in the diaphysis of the femoral stem provides better clinical and radiographic results.

Functional comparison of posterior cruciate retention and substitution knee replacement

Thirty-eight matched pairs of osteoarthritic knees from patients who underwent primary total knee replacements with minimum 2 years of followup were studied to compare the functional outcome between a cruciate retention and posterior stabilized design with essentially identical articulation surfaces. Patients were matched for age, weight, gender, diagnosis, activity, deformity of the knee, type of tibial component, and duration of followup. The patients were evaluated functionally by three methods: the Knee Society scoring system; a self-administered questionnaire; and an activity rating based on distance walked. In addition, in vivo fluoroscopic examination was performed in 10 cruciate retention and 10 posterior stabilized knees to determine the functional knee kinematics. Results showed that by patient self-assessment, functional improvement was achieved in 35 (92%) cruciate retention knees and 36 (95%) posterior stabilized knees. There was no statistically significant difference between the two groups in the clinical evaluations. Fluoroscopic kinematics showed that the posterior stabilized knee experienced anteroposterior femorotibial translation more similar to the normal knee during normal gait and deep knee bend. These clinically equivalent results are not in agreement with the predicted better functional results of cruciate retained knees as determined by gait studies.

[The investigation on the safety and immunogenicity of inactived hepatitis A vaccine AVAXIM]

OBJECTIVES

To investigate the safety and immunogenicity of AVAXIM in children and adults.

METHODS

One hundred and twenty-one children aged 6 - 12 years and 108 adults with negative HAV antibody, were inoculated by 0, 6 month procedure with inactivated HAV vaccine produced by Pasteur Merieux Connaught (AVAXIM 160 antigen unit).

RESULTS

The positive rates of anti-HAV IgG among children group and adult group were 98.15% and 94.17% respectively after one month of first inoculation, and became 100% and 97.22% after one month of second inoculation. The antibody positive rate was higher in children than in adults, but did not show statistical significance (P < 0.05). The side effects of AVAXIM inoculation were mild, mainly local pain with occurrences 1.7% - 2.8% in both groups. No serious systemic and local reactions were noticed.

CONCLUSION

AVAXIM had good safety and immunogenicity, seen not only in adults, but also in children.

Retrieval of geophysical parameters from moderate resolution imaging spectroradiometer thermal infrared data: evaluation of a two-step physical algorithm

A two-step physical algorithm that simultaneously retrieves geophysical parameters from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements was developed. The retrieved geophysical parameters include atmospheric temperature-humidity profile, surface skin temperature, and two surface emissivities within the shortwave (3-5-microm) and the longwave (8-14.5-microm) regions. The physical retrieval is accomplished in two steps: (i) The Tikhonov regularization method is employed to generate a regularization solution along with an optimum regularization parameter; (ii) the nonlinear Newtonian iteration algorithm is carried out with the regularization solution as a first-guess profile to obtain a final maximum probability solution for geophysical parameters. The algorithm was tested with both simulated and real MODIS Airborne Simulator (MAS) data. Sensitivity studies on simulated MAS data demonstrate that simultaneous retrievals of land and atmospheric parameters improve the accuracy of the retrieved geophysical parameters. Finally, analysis and accuracy of retrievals from real MAS data are discussed.

Total synthesis of the ansamycin antibiotic (+)-thiazinotrienomycin E

The first total synthesis of (+)-thiazinotrienomycin E (1), member of a novel class of cytotoxic ansamycin antibiotics, has been achieved. Key features of the synthetic strategy include (a) the efficient construction of sulfone 7 incorporating TBS protection of the aniline, (b) an improved synthesis of allyl chloride (-)-6, the advanced intermediate employed in our trienomycins A and F total syntheses, (c) application of the Kocienski modified Julia protocol to elaborate the E,E,E-triene subunit in a stereo-controlled fashion, (d) an efficient union of sulfone 7 with advanced iodide 62, and (e) Mukaiyama macrolactamization to access the thiazinotrienomycin macrocyclic ring.

Selecting anti-HBsAg fab phage antibodies from the phage antibody library

OBJECTIVE

Selecting Fab phage antibodies to HBsAg from the phage antibody library.

METHODS

The phages displaying antibody fragments were subjected to three rounds of panning with HBsAg coated in solid phase.

RESULTS

The eluted phages were enriched nearly 80-fold, and the percentage of recombinant clones increased from 17% to 100% after the third round of panning. The HBsAg specific monoclonal antibodies were determined by ELISA. These antibodies combined specifically with HBsAg, but not with BSA and HAV antigens.

CONCLUSION

Our work on constructing human immunoglobulin combinatorial library and selecting anti-HBsAg Fab phage antibodies would be beneficial to the further study on the production of soluble Fab antibodies.

Total hip arthroplasty with use of the Metasul metal-on-metal articulation. Four to seven-year results

BACKGROUND

Total hip replacements with a metal-on-metal articulation were commonly used until the mid-1970s; most were then abandoned in favor of hip replacement with a metal-on-polyethylene articulation. The reason for this change was primarily early cup loosening, which was more prevalent with these metal-on-metal designs than it was with metal-on-polyethylene designs. In the late 1980s, a metal-on-metal design with improved clearance (adequate space between the femoral head and the acetabular articulation surface to allow fluid film lubrication and clearance of any debris from within this joint), metal hardness, and reproducible surfaces was introduced by Sulzer Orthopedics in Switzerland. Orthopaedic surgeons were interested in this Metasul articulation because the contribution of polyethylene wear particles to the failure of total hip replacements had become evident. This study was undertaken to review the clinical performance of this implant and to determine if early acetabular loosening or revision and wear and osteolysis were prevalent.

METHODS

Between 1991 and 1994, seventy patients (seventy hips) had a total hip replacement with the Metasul metal-on-metal articulation and a cemented Weber cup. Nine patients died less than four years after the replacement; none of these deaths were related to the operation. Five patients were not available for radiographic evaluation, but they were contacted and it was known that the hip was not painful and had not been revised. Fifty-six patients (fifty-six hips) had complete clinical and radiographic data four to 6.8 years after the operation, and they made up the study group. The patients were evaluated with use of the Harris hip score, a patient-self-assessment form, and radiographs.

RESULTS

At an average of 5.2 years (range, four to 6.8 years) after the operation, the average total Harris hip score for the fifty-three patients who did not have a revision was 89.6 points (range, 62 to 100 points). The average Harris pain score was 41.0 points (range, 30 to 44 points), and the average Harris limp score was 9.4 points (range, 5 to 11 points). One patient had revision of a loose cup, but there were no other loose acetabular components in the series. Two patients had revision of the acetabular component because of dislocation. No patient had a loose or revised femoral component. Therefore, the mechanical failure rate was one (2 percent) of fifty-six patients. Thirty-six of forty-seven patients who completed the patient-self-assessment form rated their result as excellent; seven, as very good; two, as good; one, as fair; and one, as poor. Wear could not be measured on radiographs because of the metal-on-metal articulation. No hip had radiographic evidence of acetabular osteolysis and two hips had calcar resorption, but there was no other radiographic evidence of focal osteolysis.

CONCLUSIONS

Our four to seven-year experience with this articulation surface indicates that the clinical results are similar to those of total hip replacements with a metal-on-polyethylene articulation. We believe that the Metasul articulation may have a role in reducing the wear that occurs with total hip replacement. The Metasul articulation appears to be particularly indicated for more active patients. A historical comparison with the reports in the literature of which we are aware indicated that the hips in our study had a lower rate of acetabular revision and loosening than did those with previous metal-on-metal designs and that they had no more acetabular loosening or osteolysis than did those with metal-on-polyethylene articulations followed for an average of five years.

Total synthesis of (+)-thiazinotrienomycin E

[formula: see text] The first total synthesis of (+)-thiazinotrienomycin E (1), member of a novel class of cytotoxic ansamycin antibiotics, has been achieved. The synthesis features a highly efficient construction of the aromatic fragment 3 incorporating TBS protection of the aniline, a significantly improved synthesis of (-)-19, an intermediate employed in our trienomycins A and F total syntheses, application of the Kocienski modified Julia protocol to elaborate the E,E,E-triene subunit, an efficient union of 3 and (+)-4, and Mukaiyama macrolactamization to access the thiazinotrienomycin macrolide.

Vicarious calibration of the moderate-resolution imaging spectroradiometer airborne simulator thermal-infrared channels

We made an experimental vicarious calibration of the Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator (MAS) thermal infrared (TIR) channel data acquired in the field campaign near Mono Lake, Calif. on 10 March 1998 to demonstrate the advantage of using high-elevation sites in dry atmospheric conditions for vicarious calibration. With three lake-surface sites and one snow-field site, we estimated the MAS noise-equivalent temperature difference as 0.7-1.0 degrees C for bands 30-32 in the 3.68-4.13-microm region and 0.1-0.5 degrees C for bands 42, 45, 46, and 48 in the 8-13.5-microm region. This study shows that the MAS calibration error is within +/-0.4 degrees C in the split-window channels (at 11 and 12 microm) and larger in other TIR channels based on the MAS data over Mono Lake and in situ measurement data over the snow-field site.

Selection of human anti-HAV McAb from a phage antibody library

The phage displaying antibody fragments were subjected to three rounds of panning with hepatitis A virus (HAV) antigen in solid phase. The eluted phage was enriched nearly 100 fold, and the percentage of recombinant clones increased from 25% to 100% after three rounds of panning. The HAV antigen-specific monoclonal antibody (McAb) was screened by sandwich ELISA, and the specificity of these antibodies was further confirmed by competitive inhibition ELISA.

[Construction of human combinatorial immunoglobulin library containing HBsAb on the surface of phage]

OBJECTIVE

To construct a human recombinant immunoglobulin library containing HBsAb.

METHODS

The mRNA isolated from peripheral blood lymphocytes of two blood donors with HBsAb were reversely transcribed to the first strand cDNA with oligo-(dT) primer. Human immunoglobulin kappa light chains and heavy chains Fd genes were amplified respectively by PCR with designed oligo nucleotide primers and the first strand cDNA templates. The kappa light chain genes were first cloned into PComb3Hss vector to construct a human recombinant light chain library. The heavy chain genes were subsequently inserted into the corresponding sites of kappa-PComb3Hss plasmid to generate a combinatorial kappa-Fd-PComb3Hss plasmid. The plasmid transformed into E.Coli.XLI-Blue and the E.Coli.XLI-Blue infected by help phage.

RESULTS

The constructed light chains library size was 1.5 x 10(5), and the recombinant frequency of kappa chain genes was 57% and the human combinatorial Fab immunoglobulin library was 5 x 10(5) members and the recombinant frequency of Fab genes was 50%. Finally, the titer of phages in the phage antibody library containing HBsAb was 5 x 10(14) CFU/ml.

CONCLUSION

Our work in constructing human immunoglobulin combinatorial library containing HBsAb will be beneficial to further study on selecting Fab phage antibodies of HBsAg from the library.

Resistant mechanisms of Candida albicans to fluconazole

OBJECTIVE

To detect the resistant mechanisms of Candida albicans to fluconazole (FCZ) at molecular biology level, since the resistance mechanisms of azole antifungal agents have been the focus of attention these years.

METHODS

Thirty-two FCZ-resistant C. albicans were selected as our test strains (MICs > or = 64 micrograms/ml). With 14-alpha-demethylase gene (ERG16 gene, target enzyme encoding gene of azoles) as our object, we chose six sets of primers from the ERG16 gene to amplify the interested fragments, and conducted Southern blot hybridization, restriction fragment length polymorphism (RFLP), and single strand conformation polymorphism (SSCP) analysis for the fragments which were amplified by the six sets of primers, and pre-resistant sensitive strains were used as controls. Three representative fragments, A66, D66 and E78, were selected to be cloned and sequenced.

RESULTS

The polymerase chain reaction (PCR) amplification showed that several tested strains were negative for some primers. However, our Southern blot analysis reminded that their resistance did not result from the lack of target enzyme coding gene. SSCP analysis showed that differences were noted between the resistant and sensitive strains and inter-resistant strains. Statistical analysis showed that the most variable sequence lied in the amplifier of the sixth pair of primer, and all the tested 32 strains showed positive results. In the 11 mutation points we found, five resulted in amino acid alterations. It is likely that one or more mutational alterations (alone or in combination) might lead to the expression of an enzyme highly resistant to the inhibitory action of FCZ which in turn is responsible for the FCZ resistant trait in these strains.

CONCLUSION

One or more mutational alterations might lead to the azole resistant trait in this strains.

Effect of stem stiffness and bone stiffness on bone remodeling in cemented total hip replacement

The hypothesis in this study is that the stem stiffness-to-bone stiffness ratio influences the incidence and type of bone remodeling and fixation with cemented total hip arthroplasty. Ninety-one patients with 99 hips had cemented stems using 3 different anatomic porous replacement designs. The APR I and APR II titanium stems with proximal porous coating on the proximal one fourth of the stem were cemented into 49 and 35 patients. The APR II-C stem, which is a cobalt-chrome stem only for cemented fixation, was cemented into 15 patients. These 3 different stem designs were used to study different metals as well as different stem shapes. The average follow-up was 4.3 years (range, 2-10 years) with all hips having 2 years' follow-up and 42 hips at least 5 years' follow-up. Bone remodeling was measured as stress shielding, calcar resorption, and distal hypertrophy on anteroposterior and lateral radiographs of the hip. Stress shielding was measured by the 4 grades described by Engh. A stem stiffness-to-femoral bone stiffness ratio was calculated from the plain radiographs with the stem stiffness known from the manufacturer and the bone stiffness calculated using measurements of the outer and inner diameters of the femur. There was no statistical difference for bone remodeling and fixation between the 3 stem shapes or 2 metal types used in these hips. No stem was loose, and only 10 had radiolucent lines. Stress shielding was statistically related to stem stiffness but was more strongly related to the axial stiffness ratio, mediolateral bending stiffness ratio, anteroposterior stiffness ratio, and torsional stiffness ratio. Stress shielding grade 3 and 4 was present in 20% of hips with a torsional stiffness ratio < 0.33, in 38% of hips with a torsional stiffness ratio of 0.34 to 0.5, and in 70% of hips with a torsional stiffness ratio > 0.5. Five-year results showed no statistical change in stress shielding, calcar resorption, and distal hypertrophy from the 2-year observations. The stem stiffness-to-bone stiffness ratio influenced bone remodeling but not fixation of these cemented stems.

Medial protrusio technique for placement of a porous-coated, hemispherical acetabular component without cement in a total hip arthroplasty in patients who have acetabular dysplasia

Twenty-four hip replacements were performed with use of a medial protrusio technique to stabilize the fit of a hemispherical metal shell in the acetabulum in nineteen patients who had dysplasia of the hip. All of the hips were followed for a minimum of five years (average, seven years; range, five to thirteen years). Six of the hips were type I, seven were type II, eight were type III, and three were type IV according to the criteria of Crowe et al. The acetabular cup was implanted with the medial aspect of its dome beyond the Kohler line (drawn from the ischium along the ilioischial line) in all hips. An autogenous graft sculpted from the femoral head was used to cover 15 to 30 percent of the superolateral portion of the cup in one type-I hip, four type-III hips, and one type-IV hip. The need for these six bone grafts could have been avoided by reaming two to three millimeters more medially or by allowing 20 percent of the superolateral portion of the cup to be uncovered. Sixty to 84 percent of each bone graft was resorbed, effectively leaving the superolateral portion of the cup uncovered. The amount of the surface of the cup that was beyond the Kohler line averaged 41 percent for the six type-I hips, 43 percent for the seven type-II hips, 41 percent for six of the type-III hips, and 44 percent for one of the type-IV hips. Crossing of the ilioischial and iliopubic lines was noted on the radiographs of two type-III and two type-IV hips. Radiographs of two type-I hips and one type-II hip showed 7 to 17 percent of the surface of the dome of the cup through the internal pelvic wall (beyond the iliopubic line). None of the twenty-four metal shells were revised. A reoperation was performed on two hips to exchange a worn polyethylene insert, and three femoral components that had been fixed without cement were revised because of mechanical loosening. Wear averaged 0.26 millimeter per year in the fourteen hips that had a titanium femoral head and 0.09 millimeter per year in the nine hips that had a cobalt-chromium femoral head. The remaining hip had a ceramic femoral head, and the wear rate was 0.09 millimeter per year. The medial protrusio technique is a predictable, reproducible method for obtaining fixation of a porous-coated, hemispherical acetabular component in a dysplastic acetabulum. The technique permits the use of a porous-coated (bone-ingrowth) component; avoids the use of support bone graft and thereby reduces the operative time; facilitates rehabilitation by permitting earlier weight-bearing of the hip; and permits the use of a modular bearing surface, which may allow future exchange of only this surface rather than revision of the entire acetabular component because of excessive wear.

Causes of and treatment protocol for instability of total hip replacement

Dislocation of the total hip replacement is a devastating complication, physically and mentally. It was determined whether there are radiographic or operative findings predictive of repeat dislocation and whether there are causes of dislocation that require immediate reoperation. A previously published classification of dislocations was used which evaluates (1) positional (no radiographic abnormality); (2) component malposition (femur or acetabulum), which is inadequate version or position of the acetabular or femoral component; (3) soft tissue imbalance (change in the length or displacement of the hip), which is a change in the muscle functional length of the hip; and (4) component malposition and soft tissue imbalance. Categories of treatment of dislocations were established that could be correlated to the cause of the dislocation: (1) Category I is a successful closed reduction; (2) Category II is a successful reoperation; (3) Category III is a reoperation with subsequent repeat dislocations successfully treated with closed reduction; and (4) Category IV is comprised of hips that require multiple reoperations for treatment of dislocations. The results are that any dislocation of any origin may be treated successfully with closed reduction so that this should be the first choice of treatment. To avoid multiple treatments, immediate reoperation should be performed if the hip is unstable when the patient is examined under anesthesia after the closed reduction. Hips with soft tissue imbalance and weakness of the abductor musculature, with or without component malposition, are most at risk for multiple operations. These hips may be considered for mechanical stability (constraint in the acetabular replacement) at reoperation.

Bilateral total hip arthroplasty comparing hydroxyapatite coating to porous-coated fixation

Fifteen patients had bilateral hip replacement with a porous-coated hip replacement in one hip and in the contralateral hip the same design, which had adjunctive hydroxyapatite coating on the porous coating. These patients were followed for an average of 6.5 years (range, 5-7.9 years). There was no difference in the clinical Harris Hip Scores between the two hips in these patients. The radiographic measurements did show improved bone remodeling in hips with adjunctive hydroxyapatite coating as measured by proximal cancellous hypertrophy and evidence of a buttress sign. The fixation of stems with hydroxyapatite coating showed fewer radiolucent lines (P = .013). The improved bone remodeling, which we had previously reported, has been maintained in these hips at intermediate-term follow-up and the fixation of the hydroxyapatite-coated stems is also now better. The results in these patients with bilateral hips, which allows complete control of the bone type, immunology, weight, activity, and age of the patient, suggests that the use of hydroxyapatite coating does provide improved fixation and the possibility of improved durability.

Hemispheric titanium porous coated acetabular component without screw fixation

One hundred fifteen hips in 108 patients with primary total hip arthroplasty using the anatomic porous replacement hemispheric acetabular component implanted without adjunctive screw fixation had a mean postoperative followup time of 6 years (range, 5-7.4 years). Clinical evaluation was performed using the Harris hip score and patient self assessment using a modified Short Form-36 questionnaire. Radiographs were measured for radiolucent lines, polyethylene wear, osteolysis, migration, and fractures. No acetabular metal shell had been revised for loosening or was radiographically loose with or without migration (more than 3 mm) at final followup. Reoperation was done in nine (8%) hips because of polyethylene insert wear or disassembly. No fracture of the acetabular bone occurred at the time of surgery or was observed on radiograph. Fixation of the metal shell was stable, with progressive radiolucent lines observed at final followup in 2% of the hips. Osteolysis was recorded in one patient with two acetabular components. The fixation of noncemented hemispheric porous coated acetabular components is more related to the technique of acetabular bone preparation and press fit implantation than to whether additional screws or peg fixation are used. Fixation of this acetabular component without screws at an average of 6 years after surgery is reproducible and predictable in primary hip arthroplasty. The design of modular polyethylene inserts has been improved and should reduce the wear rate of reoperations of the polyethylene insert.

Thermodynamic Constraints on Reflectance Reciprocity and Kirchhoff's Law

Contrary to common belief, neither reciprocity of the bidirectional reflectance distribution function (BRDF) nor the directional form of Kirchhoff's electromagnetic radiation law can be demonstrated on the basis of energy conservation. The BRDF is generally considered reciprocal as an extension of Helmholtz reciprocity, but Helmholtz reciprocity does not always hold. We describe the flaw in a thermodynamic demonstration of reciprocity that uses an enclosure calculation. Some conclusions can be drawn from the enclosure calculation, but reciprocity requires more restrictive conditions. We conclude that, although they can be violated, reciprocity and the directional form of Kirchhoff's law generally hold because of the quantum-mechanical principle of time-reversal invariance, which applies to most materials.

[Early diagnosis of nasopharyngeal carcinoma using recombinant antigens expressed in bacteria]

An enzyme-linked immunosorbent assay(ELISA) was developed by using recombinant purified early antigens, EA-D and EA-R to detect IgA antibodies in sera from nasopharyngeal carcinoma(NPC) patients. 30 sera from NPC patients and 49 sera from normal persons were detected by the developed ELISA. The serum positive rate and antibody titer were compared with immunoenzymatic method(IE) on slide with Raji cells mears. ELISA is more sensitive and specific. The serum positive rate of NPC patients was increased from 70% by IE to 100% by ELISA and 77% of the serum antibody titer reached > or = 1:200. The results show that the expressed recombinant p138 and p54 antigens are effective for detection of EA/IgA antibody in sera from NPC patients and ELISA will be a sensitive, specific and convenient method for early diagnosis of NPC.

Synthetic strategies for the preparation of precursor polymers and of microcapsules suitable for cellular entrapment by polyelectrolyte complexation of those polymers

The production of microcapsules suitable for the entrapment of mammalian cell by means of polyelectrolyte complexation has, of a necessity, led to the development of novel strategies for the preparation of relatively bioinert polymers which complex efficiently under unique conditions to produce a mechanically resilient membrane with efficient transport properties. In this communication we relate a brief overview of capsule-membrane forming systems for the immunoisolation (or potential immunoisolation) of mammalian cells, which are based upon the complexation of polyelectrolyte (PE) polymers; with emphasis on precursor synthesis and relationships between precursor polymer structure and capsule membrane stability.

Molecular replacement studies on crystal structure of DesB1-B2 Despentapeptide (B26-B30) insulin

Using the crystal structure of Despentapeptide (B26-B30) insulin (DPI as the search model, the crystal structure of DesB1-B2 Despentapeptide (B26-B30) insulin (DesB1-2 DPI) has been studied by the molecular replacement method. There is one DesB1-2 DPI molecule in each crystallographic asymmetric unit. The cross rotation function search and the translation function search show apparent peaks and thus determine the orientation and position of DesB1-2 DPI molecule in the cell respectively. The subsequent three-dimensional structural rebuilding and refinement of DesB1-2 DPI molecule confirm the results by molecular replacement method.

Cementless revision of total hip arthroplasty using the anatomic porous replacement revision prosthesis

This study reports the results of revision total hip arthroplasty with the Anatomic Porous Replacement Revision Hip System (Intermedics Orthopedics, Austin, TX) to investigate the value of cementless fixation. Sixty-six hips in 65 patients were followed for a mean of 4.7 years in patients with a mean age of 56 years. Thirty-six patients were categorized as Charnley class A, 16 as class B, and 13 as class C. Forty (61%) of the femurs were classified before surgery as having loss of bone distal to the intertrochanteric line. Thirty-two (48%) of the femurs required augmentation with demineralized strut cortical allografts, 5 (8%) required bulk femoral allografts, and 12 hips (18%) required acetabular allografts. Overall, 4 stems (6%) and 2 acetabular components (4%) required further revision surgery. The reason for further revision in 1 stem and both acetabular components was allograft failure. Fifty-six (85%) hips had excellent or good Harris hip scores. Ninety percent of hips had no or slight pain, and 90% allowed patients to walk with no or slight limp. Those hips that had hydroxyapatite coating added to the porous coating had statistically improved Harris hip scores for both pain and limp. Stable fixation was present in 95% of stems. Demineralized strut grafts healed in 30 of 32 hips. Thirty-nine of 44 noncemented revision sockets had no radiolucent lines and there were no loose components. Cementless fixation was effective for these hips.