Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma

PURPOSE

Diffuse and nodular forms of mantle-cell lymphoma (MCL) are consistently associated with poor prognosis. In an effort to improve the outcome, we adopted a treatment plan that consisted of four courses of fractionated cyclophosphamide (CY) 1,800 mg/m2 administered with doxorubicin (DOX), vincristine (VCR), and dexamethasone (Hyper-CVAD) that alternated with high-dose methotrexate (MTX) and cytarabine (Ara-C). After four courses, patients were consolidated with high-dose CY, total-body irradiation, and autologous or allogeneic blood or marrow stem-cell transplantation.

PATIENTS AND METHODS

Forty-five patients were enrolled; 25 patients were previously untreated, 43 patients had Ann Arbor stage IV disease, and 42 patients had marrow involvement. Forty-one patients had diffuse histology, two patients had nodular, and two patients had blastic variants.

RESULTS

Hyper-CVAD/MTX-Ara-C induced a response rate of 93.5% (complete response [CR], 38%; partial response [PR], 55.5%) after four cycles of pretransplantation induction chemotherapy. All patients who went on to undergo transplantation achieved CRs. For the 25 previously untreated patients, the overall survival (OS) and event-free survival (EFS) rates at 3 years were 92% (95% confidence interval [CI], 80 to 100) and 72% (95% CI, 45 to 98) compared with 25% (95% CI, 12 to 62; P = .005) and 17% (95% CI, 10 to 43; P = .007), respectively, for the previously treated patients. When compared with a historic control group who received a CY, DOX, VCR, and prednisone (CHOP)-like regimen, untreated patients in the study had a 3-year EFS rate of 72% versus 28% (P = .0001) and a better OS rate (92% v 56%; P = .05). Treatment-related death occurred in five patients: all were previously treated and two received allogeneic transplants.

CONCLUSION

The Hyper-CVAD/MTX-Ara-C program followed by stem-cell transplantation is a promising new therapy for previously untreated patients with MCL.

Noninvasive diagnosis of oral neoplasia based on fluorescence spectroscopy and native tissue autofluorescence

OBJECTIVE

To evaluate the clinical potential of fluorescence spectroscopy (a noninvasive technique for assessing the chemical and morphologic composition of tissue) for in vivo detection of oral cavity neoplasia.

DESIGN

A fluorescence spectroscopy system recorded spectra from oral cavity sites in 8 healthy volunteers and in 15 patients with premalignant or malignant oral cavity lesions at 337-, 365-, and 410-nm excitation wavelengths in the emission range of 350 to 700 nm. Fluorescence peak intensities and spectral line shapes were compared and diagnostic algorithms were developed to distinguish normal sites from abnormal sites.

SETTING

The head and neck cancer clinic at a tertiary referral center in Houston, Tex.

RESULTS

Differences were found in spectra from normal, dysplastic, and malignant oral mucosa. The fluorescence intensity of normal mucosa was greater than that of abnormal areas. In addition, the ratio of red region (635-nm) to blue region (455-490-nm) intensities was greater in abnormal areas. Diagnostic discrimination was achieved when test site spectra were compared with spectra from a normal site in the same patient. One diagnostic algorithm based on spectra at 337 nm gave a sensitivity of 88% and a specificity of 100%.

CONCLUSIONS

Consistent differences exist between the fluorescence spectra of abnormal and normal oral mucosa. Therefore, fluorescence spectroscopy has the potential to improve the noninvasive diagnosis of oral cavity neoplasia. Further studies will better define the role of this technique in the detection of premalignant and early oral cancer lesions.

Population pharmacokinetics of ondansetron: a covariate analysis

AIMS

To construct a population model to account for the variability in ondansetron pharmacokinetics and to evaluate methods for the efficient development of population models.

METHODS

Population models were developed using 99 subjects consisting of paediatric patients, young, elderly and aged volunteers. A two compartment pharmacokinetic model with a zero order input was used to describe the pharmacokinetics of ondansetron. Three stepwise methods were proposed and used alongside a three step approach to develop population models with both rich and sparse data sets. The stepwise methods were based on obtaining empirical Bayes posterior estimates of pharmacokinetic parameters within a nonlinear mixed effect modelling (NONMEM) program. The parameters were then regressed against covariates in a stepwise procedure. Variance parameters were obtained by fitting the proposed population model to the data in one further NONMEM run. The population model was validated against a test data set of 54 subjects, including children, young and elderly patients and volunteers.

RESULTS

The population model adequately described the differences in ondansetron pharmacokinetics between paediatric patients, young, elderly and aged volunteers. Different covariates were identified by the various methods. Weight was found to have a strong positive linear relationship with all four pharmacokinetic parameters. Clearance showed a weak negative relationship with age. Males were found to have a greater clearance than females after weight adjustment.

CONCLUSIONS

The stepwise search procedures potentially are capable of considerably reducing the time required to develop population pharmacokinetic models. The model developed for ondansetron gave accurate predictions of both the concentration-time profile and variability in an independent data set.

Bayesian optimal design in population models for haematologic data

We introduce a population model to design optimal apheresis schedules to collect blood stem cells from cancer patients. Blood stem cells are collected prior to the patient undergoing high-dose chemoradiotherapy and are returned after this treatment to enable reconstitution of the white blood cell components. Maximizing the number of cells collected in as few apheresis as possible is desirable. We use a longitudinal data model with random effects to describe profiles of individual patients. A hierarchical prior model introduces common mean profiles for patients undergoing different treatments. We find the optimal apheresis schedule for a new patient by minimizing an expected loss over the posterior predictive distribution of the patient's predicted CD34 profile. We implement estimation of the model and solution of the optimal design problem by a simulation approach, which allows us to accommodate arbitrary shapes for the profiles and realistic loss functions that include relative penalties for the number of scheduled stem cell collections and for collecting fewer than a specified target quantity of total collected stem cells.

Changes in third carpal bone articular cartilage after synovectomy in normal and inflamed joints

OBJECTIVE

To determine if arthroscopic synovectomy in normal and inflamed joints had temporal or site-related effects on articular cartilage.

STUDY DESIGN

Alterations in equine third carpal bone articular cartilage were studied at two time periods: groups 1 and 2 (6 weeks) and groups 3 and 4 (2 weeks) after synovectomy in normal (groups 2 and 4) and inflamed carpi (groups 1 and 3).

ANIMAL POPULATION

16 carpi from eight horses.

METHODS

Biochemical and biomechanical properties of dorsal and palmar articular cartilage were determined by radioloabeling, proteoglycan (PG) extraction, chromatography, electrophoresis, and indentation testing.

RESULTS

Synovectomy in inflamed joints produced the greatest concentration of newly synthesized PG in articular cartilage by 2 weeks. Synovectomy in normal joints produced significantly greater newly synthesized PG in articular cartilage by 6 weeks. Dorsal sites had greater newly synthesized and endogenous PG in some groups. Chromatographic profiles of newly synthesized PG demonstrated early and late PG peaks. Electrophoresis of late PG peak showed a toluidine blue-positive band that comigrated with human A1D1 PG monomer in the two groups with the most newly synthesized PG> This band was reactive with monoclonal antibody 1C6 specific for the hyaluronic acid-binding region of aggrecan. For the material properties evaluated, only Poisson's ratio was significantly decreased between groups as a function of time (6 weeks < 2 weeks). and this was most pronounced in the thicker dorsal sites.

CONCLUSIONS

Synovectomy in inflamed joints produced site-specific, significantly greater responses in articular cartilage as compared with synovectomy in normal joints.

CLINICAL RELEVANCE

Synovectomy may not be beneficial to the articular cartilage in inflamed joints.

Contrast radiography of the lower urinary tract in the management of obstructive urolithiasis in small ruminants and swine

Contrast radiographic visualization of the small ruminant and porcine lower urinary tract is an infrequently used modality for the evaluation and management of obstructive urolithiasis. The administration of contrast medium through a tube cystostomy catheter used to divert urine flow until the resolution of the obstruction may provide an easy method to evaluate the status of the urethral obstruction. Contrast fluoroscopy is utilized to monitor and visualize therapeutic flushing of the urethra. A review of 26 patients seen at the Veterinary Medical Teaching Hospital suggested that among the radiographic techniques used, positive contrast normograde cystourethrography through the tube cystostomy catheter allowed the best visualization of the lower urinary tract structures and enabled assessment of the resolution of the obstructive lesion.

p53 and RB expression predict progression in T1 bladder cancer

The optimal clinical management of minimally invasive (stage T1) bladder cancer is controversial. T1 bladder cancers share characteristics of both noninvasive (Ta) papillary cancer and high stage, muscle-invasive bladder cancers. Patients with T1 bladder cancer have a higher risk of cancer progression and death than do patients with Ta bladder cancer. However, this risk is much lower than that of patients with high-stage bladder cancers. Methods of identifying T1 bladder cancer patients at greatest risk for progression may significantly improve clinical management. We retrospectively evaluated two tumor suppressor genes, p53 and RB, as potential prognostic markers for progression in a cohort of 45 patients with pT1 bladder cancer. Median follow-up for these individuals was greater than 3.5 years. Of this group, 58% had altered p53 expression based on positive p53 immunostaining. Three patterns for RB nuclear protein staining were observed: absent, heterogeneous (normal), and strongly homogeneous. Progression-free survival was similar for patients with loss of RB protein expression and those with apparent overexpression of RB protein. Therefore, both staining patterns were considered abnormal. Patients with normal expression of both proteins (i.e., p53 negative and RB heterogeneously positive) had an excellent outcome, with no patient showing disease progression, whereas patients with abnormal expression of either or both proteins had a significant increase in progression (P = 0.04 and P = 0.005, respectively). These data support the stratification of T1 bladder cancer patients based on p53 and RB nuclear protein status and suggest that patients with normal protein expression for both genes can be managed conservatively, whereas patients with alterations in one and particularly both genes require more aggressive treatment.

Coincident renal cell carcinoma and nonHodgkin's lymphoma: the M. D. Anderson experience and review of the literature

PURPOSE

We recently observed nonHodgkin's lymphoma and renal cell carcinoma occurring simultaneously in several patients. We determine whether the incidence of co-occurrence of the 2 malignancies is greater than expected based on the incidence of each disease in the general population.

MATERIALS AND METHODS

Patients diagnosed with simultaneous renal cell carcinoma and nonHodgkin's lymphoma were identified through the medical informatics data base at our cancer center. Charts of all patients were reviewed to collect detailed demographic information and confirm both diagnoses. United States population based cancer statistics (Surveillance, Epidemiology and End Results Program data) were used to arrive at the expected age adjusted incidence of co-occurrence of these diagnoses, and statistical analysis was performed to ascertain any differences between expected and observed incidences.

RESULTS

We identified 41 cases with both diagnoses between 1954 and 1995, including 21 diagnosed after 1987. The latter group was used for statistical analysis. The observed rates of renal cell carcinoma developing in the nonHodgkin's lymphoma population (1.86) and nonHodgkin's lymphoma developing in the renal cell carcinoma population (2.67) were greater than expected and both reached statistical significance.

CONCLUSIONS

There is a higher than expected incidence of co-occurrence of renal cell carcinoma and nonHodgkin's lymphoma. The cause remains speculative.

Coincident renal cell carcinoma and nonHodgkin's lymphoma: the M. D. Anderson experience and review of the literature

PURPOSE

We recently observed nonHodgkin's lymphoma and renal cell carcinoma occurring simultaneously in several patients. We determine whether the incidence of co-occurrence of the 2 malignancies is greater than expected based on the incidence of each disease in the general population.

MATERIALS AND METHODS

Patients diagnosed with simultaneous renal cell carcinoma and nonHodgkin's lymphoma were identified through the medical informatics data base at our cancer center. Charts of all patients were reviewed to collect detailed demographic information and confirm both diagnoses. United States population based cancer statistics (Surveillance, Epidemiology and End Results Program data) were used to arrive at the expected age adjusted incidence of co-occurrence of these diagnoses, and statistical analysis was performed to ascertain any differences between expected and observed incidences.

RESULTS

We identified 41 cases with both diagnoses between 1954 and 1995, including 21 diagnosed after 1987. The latter group was used for statistical analysis. The observed rates of renal cell carcinoma developing in the nonHodgkin's lymphoma population (1.86) and nonHodgkin's lymphoma developing in the renal cell carcinoma population (2.67) were greater than expected and both reached statistical significance.

CONCLUSIONS

There is a higher than expected incidence of co-occurrence of renal cell carcinoma and nonHodgkin's lymphoma. The cause remains speculative.

Hodgkin's disease: correlation of clinical characteristics with probabilities for negative lymphangiogram vs. negative laparotomy findings in patients with Stage I supradiaphragmatic presentations vs. those in patients with Stage II

PURPOSE

At a time both when late complications and second malignancies have become a growing concern and when staging laparotomy has been largely abandoned and comparative studies for staging Hodgkin's disease by state of the art computed tomography (CT) vs. lymphangiography have revealed minimal differences in results for these procedures, our purpose for undertaking this study was twofold. Our initial reason was to determine and compare probabilities for negative abdominal findings for patients with Stage I presentations with those for patients with Stage II as determined by lymphangiography and subsequently by laparotomy for those patients who had negative lymphangiograms. Our second reason, being an extension of the first, was to create a resource that can be used in conjunction with other information for arriving at appropriate treatment decisions including giving either more or particularly less than standard institutional therapy and especially with respect to the abdomen.

METHODS AND MATERIALS

Data on 714 patients with prelymphangiogram Stage I-II upper torso presentations of Hodgkin's disease were entered prospectively in our database between 1968 and 1987. Twenty-eight with lymphocyte predominant disease, who had both negative lymphangiogram and negative laparotomy findings and 17 with questionable diagnoses of lymphocyte-depleted or unclassified disease were excluded from subsequent analyses of 669 patients with nodular sclerosis (NS) and mixed cellularity (MC) diagnoses.

RESULTS

Stage I: in final logistic models, negative lymphangiogram findings were associated strongly with a combination of no constitutional symptoms and nodular sclerosis histology, whereas negative laparotomy findings correlated strongly with a combination of no constitutional symptoms and female sex. Predicted probabilities depended on the ratios of favorable to unfavorable characteristics. Stage II: in final logistic models, negative lymphangiogram findings were associated strongly with a combination of no constitutional symptoms, nodular sclerosis histology, age <40 years, and <4 involved sites, whereas negative laparotomy findings correlated strongly with a combination of <4 involved sites and mediastinal disease. Predicted probabilities again depended on the ratios of favorable to unfavorable characteristics.

CONCLUSION

This study demonstrated that probabilities for negative abdominal findings for patients with supradiaphragmatic presentations of NS and MC Hodgkin's disease depended on: 1) whether the disease presented as Stage I or as Stage II; 2) whether staging was limited to a lymphangiogram or whether it included a laparotomy; and 3) or whether the clinical features associated with the presenting stage and methods of staging were favorable or unfavorable.

Elevated levels of biologically active soluble CD40 ligand in the serum of patients with chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is an indolent lymphoproliferative disorder manifested by low growth fraction and prolonged survival of the malignant cells. The mechanisms that enable CLL cells to live longer and to resist apoptosis remain unclear. Because the malignant CLL cells express CD40 and Fas receptors, which can transduce cell-survival and cell-death signals, we examined the role of CD40 in the growth regulation of CLL cells and its interaction with Fas-mediated and fludarabine-induced apoptosis in vitro. Primary CLL cells underwent spontaneous apoptosis in culture, which was enhanced by exogenous human Fas ligand (FasL) or fludarabine. Exogenous CD40L rescued CLL cells from spontaneous apoptosis in a dose-dependent manner, and caused CLL cells to resist apoptosis induced by FasL or fludarabine. Patients' autologous plasma rescued CLL cells from spontaneous apoptosis, an effect that could be reversed with anti-CD40 ligand (CD40L) antibodies. The levels of soluble CD40 ligand in the sera of 51 CLL patients and 55 healthy donors were determined by enzyme-linked immunosorbent assay. The mean soluble CD40L level in normal donors was 0.29 ng/ml compared to a mean value of 0.80 ng/ml in CLL patients (P < 0.001). CD40L up-regulated bcl-X(L) mRNA but not bcl-2 in CLL cells within 3-6 h in culture. Our results demonstrated that serum of patients with CLL contained elevated levels of biologically active soluble CD40L, and that CD40L can prolong survival of CLL cells and mediate their resistance to FasL and fludarabine in vitro.

CD30 ligand in lymphoma patients with CD30+ tumors

PURPOSE

CD30 ligand (CD30L), which is expressed on resting B and activated T lymphocytes, can induce cell death in several CD30+ cell lines. Patients with CD30+ tumors (Hodgkin's disease and Ki-1+ non-Hodgkin's lymphoma) frequently have elevated soluble CD30 (sCD30) levels in their serum, which correlates with a poor prognosis. The role of sCD30 in protecting tumor cells from CD30L-mediated cell death and the pattern of CD30L expression on human peripheral-blood lymphocytes (PBLs) of normal donors and patients with CD30+ tumors are investigated.

MATERIALS AND METHODS

CD30L surface protein expression was determined by two-color flow cytometry on PBLs of patients with CD30+ tumors and normal individuals. CD30L levels were determined on subsets of PBLs before and after stimulation with phytohemagglutinin (PHA), anti-CD3 antibody, or CD40L. sCD30 was measured by enzyme-linked immunosorbent assay (ELISA). The apoptotic activity of membrane-bound CD30L was tested in a CD30+ cell line by the annexin V-binding method.

RESULTS

Unstimulated T lymphocytes of normal donors and patients with lymphoma rarely expressed CD30L surface protein, but were able to express it after stimulation with PHA or anti-CD3 antibody. Resting B cells of patients with CD30+ tumors had lower levels of detectable surface CD30L compared with normal donors (mean, 55% and 80.6%, respectively; P = .0008). Patients with high levels of serum sCD30 had lower detectable levels of CD30L on their PBLs (R2 = .72, P = .0008) and exogenous sCD30 blocked membrane-bound CD30L-mediated apoptosis in a CD30+ cell line.

CONCLUSION

In patients with CD30+ tumors, sCD30 can decrease the availability of CD30L on PBLs. Blocking the apoptosis-inducing activity of CD30L by its soluble receptor may explain how CD30+ tumors escape immunosurveillance and may be related to the reported poor prognosis of patients who have elevated sCD30 levels.

Cytogenetic and molecular genetic analysis of a pediatric pleomorphic sarcoma reveals similarities to adult malignant fibrous histiocytoma

Cytogenetic and molecular genetic studies were performed on a pleomorphic sarcoma removed from the left atrium of a 15-year-old girl. Histologic analysis was consistent with a storiform-pleomorphic malignant fibrous histiocytoma (MFH). Although MFH is the most common soft-tissue sarcoma of late adulthood. It is extremely rare in childhood and its existence in the pediatric population remains controversial. Cytogenetic analysis revealed several alterations previously associated with adult MFH, including abnormalities of chromosomal bands 11p11 and 19p13. Moreover, the tumor demonstrated homogeneously staining regions (HSR) and double minute chromosomes (dmin) suggestive of gene amplification. We therefore screened the case for amplification of genes localized to chromosomal bands 12q13-14, including the putative protooncogenes MDM2, CDK4, SAS, CHOP, and CLI, which are frequently amplified and overexpressed in adult MFH. Southern and Northern blot analysis confirmed the coamplification of MDM2, CDK4, SAS, and CHOP. To our knowledge, such coamplification studies of the 12q13-14 amplicon have not been previously detected in pediatric MFH. Our results provide cytogenetic and molecular genetic evidence that pediatric and adult MFH are histogenetically related entities.

Allogeneic blood or marrow transplantation for chronic lymphocytic leukaemia: timing of transplantation and potential effect of fludarabine on acute graft-versus-host disease

The outcome of allogeneic haemopoietic transplants including the rate of immune complications for patients with chronic lymphocytic leukaemia (CLL) refractory to or relapsing after chemotherapy with fludarabine was analysed. Fifteen patients with advanced CLL who received allogeneic transplantation were prospectively analysed. All patients had previously received chemotherapy with fludarabine for 3-15 courses; 12 were refractory. The median number of circulating CD4+ and CD8+ lymphocytes at the time of transplant was 0.49 x 10(9)/l and 0.23 x 10(9)/l, respectively. One patient was transplanted from a one HLA-antigen mismatched unrelated donor. Three others received a one or two antigen mismatched graft and 11 had HLA-identical sibling donors. Patients received cyclosporine or tacrolimus in addition to methotrexate or methylprednisolone for prophylaxis of acute graft-versus-host disease (aGVHD). Fourteen patients engrafted; one patient had graft failure, but recovered after therapy with intravenous immunoglobulin. 13 (87%) achieved complete remission (CR). Nine (53%) remain alive and in CR with a median follow-up of 36 (range 3-60) months. None developed visceral graft-versus-host disease. These data compared favourably to published reports in other leukaemia patients and for patients with CLL who received a comparable immunosuppressive therapy but without prior fludarabine exposure. This data indicates that allogeneic haemopoietic transplantation can induce durable remission in patients with CLL refractory to fludarabine and that it is reasonable to delay transplantation until failure of fludarabine therapy. It also suggests that prior exposure to fludarabine may decrease the incidence of severe aGVHD, possibly through its immunosuppressive effects. Further studies are warranted to evaluate this observation.

Physiology of chemotherapy-induced emesis and antiemetic therapy. Predictive models for evaluation of new compounds

The physiology of emesis has been studied for several hundred years, focusing on the different centres involved and the mechanics of expulsion. The vomiting centre receives inputs from various emetic detectors such as the gut, the vestibular labyrinths and the chemoreceptor trigger zone. Emesis is a common disabling effect in motion sickness, postoperative conditions and in radio- and chemotherapy. Our current understanding of the mechanisms has been provided mainly by the recent introduction of serotonin 5-HT3 receptor antagonists into therapeutic use. Nevertheless, despite the considerable advances made in the understanding of the different pathways involved in emesis, there are number of areas that still require experimental investigation. Different animal and human models are available to study the physiology of emesis and to evaluate the antiemetic activity of new compounds, but they need to be predictors of clinical situations.

The effect of ondansetron on the pharmacokinetics and pharmacodynamics of temazepam

The objective of this study was to determine the effects of ondansetron on the pharmacokinetics of temazepam and on pharmacodynamics relevant to its use as oral premedication. Twenty-four healthy volunteers (12 of each sex) were administered the following oral treatments in a randomised, double-blind crossover design: temazepam 20 mg plus placebo; or temazepam 20 mg plus ondansetron 8 mg. Blood samples were taken for plasma temazepam assay at intervals up to 32 h after administration. In addition, a brief battery of psychomotor tests was administered 1 h prior to dosing and 1 and 4 h after dosing. Analysis of the derived pharmacokinetic parameters showed no differences between the treatments described above. Analysis of data from the dynamic measures likewise showed no difference between the treatments. It was concluded that the co-administration of ondansetron did not influence the pharmacokinetics or pharmacodynamic actions of temazepam.

Trisomy 7 by dual-color fluorescence in situ hybridization: a potential biological marker for prostate cancer progression

Smear preparations from fine-needle aspirates of 30 prostatic carcinomas obtained from radical prostatectomy specimens were examined by a dual-color fluorescence in situ hybridization (FISH) method for the presence of chromosome 7 trisomy (chromosome 9 was used as a control). The frequency of cells with trisomy 7 was determined in tumor cells and normal prostatic epithelial cells in each specimen. Comparison between the tumor and normal cells from the same patients showed that within all stages, the frequency of trisomy 7/disomy 9 cells in the tumor cells was significantly higher than that observed in the normal cells (P < 0.0001). Furthermore, the mean frequency of cells with trisomy 7/disomy 9 in advanced stages was significantly elevated over the mean frequency observed in organ-confined tumors (P = 0.02). These results are consistent with our previous data on paraffin-embedded prostate tissue sections using single-color FISH procedures. However, the method used in the present study enhances the accuracy of distinguishing trisomic 7 cells from potentially triploid (trisomy 7/trisomy 9) cells. Furthermore, the use of fine-needle aspirates rather than paraffin sections provides an easy method to examine whole nuclei. Our study also suggests that FISH provides a better measure of genetic instability (e.g., aneuploidy) in prostate tumors than flow cytometry.

Biochemical and biomechanical alterations in equine articular cartilage following an experimentally-induced synovitis

The effects of inflammation on the biochemical and biomechanical properties of articular cartilage at two sites (dorsal and palmar) from the radial facet of the equine third carpal bone were examined in response to a synovitis induced with Escherichia coli lipopolysaccharide (LPS). Four groups were studied. In group 1 synovitis was induced at time zero and evaluated at week 6. Group 2 was the sham-treated control for group 1. In group 3 synovitis was induced at time zero and evaluated at week 2. Group 4 was the sham-treated control for group 3. There was a significant increase (P < 0.05) in newly synthesized proteoglycan PG from both sites in group 3 as compared to the sham-treated groups and group 1. No significant difference in the endogenous PG concentration between groups or sites was detected. Sepharose CL-2B revealed two peaks of newly synthesized PG in all groups; an early peak (Kav 0.11-0.13) and a late peak (Kav 0.48-0.64). Newly synthesized PG profiles from sham-treated groups and group 3 were similar, but the group 3 PG profile exhibited a more pronounced early peak. Conversely, the PG profile from group 1 demonstrated a more prominent late peak. Electrophoresis and Western blot analysis of the pooled late PG peak fractions from the sham-treated and group 1 showed a single toluidine blue stained band from both sites which reacted with monoclonal antibody (MAb) 1C6. By contrast, the late peak from the palmar site in group 3 showed an additional faster moving component on composite gels which did not react with MAb 1C6. There was a significant decrease in Poisson's ratio and a significant increase in cartilage thickness in groups 1 and 3 which had received synovitis. The increase in cartilage thickness of groups 1 and 3 was also significantly affected by site (dorsal > palmar). There was no significant difference in aggregate modulus or permeability constant among groups. Primary joint inflammation induced by LPS alters the biochemical and biomechanical properties of the articular cartilage as a function of time and site. An increase in chondrocyte PG synthesis in the early period following synovitis may be a reparative response to the inflammatory insult. Continued alterations in the qualitative PG composition in the later period following synovitis may represent a shift in chondrocyte metabolism to repopulate the existing cartilage matrix.

Influence of methylprednisolone acetate on osteochondral healing in exercised tarsocrural joints of horses

OBJECTIVE

To evaluate joint function and healing of surgically created full-thickness articular cartilage defects in exercised horses after intra-articular administration of methylprednisolone acetate (MPA; 120 mg) and sterile saline solution in the contralateral limb.

DESIGN

Experimental investigation.

SAMPLE POPULATION

12 healthy, sound, radiographically normal horses with induced full-thickness osteochondral lesions on the medial and lateral trochlear ridges of the tali.

PROCEDURE

Two 8.4-mm-diameter full-thickness articular cartilage lesions were created in each tarsocrural joint (12 horses [24 tarsocrural joints]); 1 was in a weight-bearing (WB) position and the other in a less weight-bearing (LWB) position. Each horse was maintained on a standardized exercise protocol (stall rest, days 0-6; walking, days 7-12; and treadmill, days 13-42) and evaluated throughout the study for changes in joint circumferences, synovial fluid, radiographs, lameness, and scintigraphy. 6 horses were euthanatized on day 42, and 6 on day 180. Gross morphometric assessment was performed, using an image analysis system on a projected color slide of the defect. The type of repair tissue, based on gross appearance, was expressed as a percentage of the total defect for each osteochondral defect. Histochemical assessment was performed, using safranin-O staining for proteoglycans and an image analysis system to express the area of stain uptake. Histomorphometric assessment was performed on H&E-stained sections, using an image analysis system. The repair tissue filling the defect was categorized as to tissue type and expressed as a percentage of the total defect area. Synovial membrane specimens were assessed semiquantitatively on H&E-stained sections for changes in character. Significance was established at P < 0.05.

RESULTS

Joint circumference was significantly increased in the saline, compared with the MPA-treated, limbs on days 7, 12, and 42. Synovial fluid WBC counts were significantly increased in the MPA-treated limbs on day 42. Gross osteochondral defects had a greater percentage of mature repair tissue in saline-treated joints (30.8% LWB, 23% WB), compared with MPA-treated joints (0% LWB, 0% WB) at 42 days Histomorphometric assessment of the repair tissue indicated significant differences with regard to the quality of repair in the saline-treated (34% fibrous tissue LWB, 19.4% fibrous tissue WB) versus MPA-treated (2.5% fibrous tissue in LWB and WB) joints at 42 days. Microscopically, the percentage of fibrocartilage in the LWB (MPA, 23.7%; saline, 24.8%) was significantly greater than that in the WB (MPA, 14.6%; saline, 15.4%) site at day 180. The MPA-treated limbs had greater villous hyperplasia, edema, and extent of inflammation within the synovial membrane than did saline-treated limbs (days 42 and 180).

CONCLUSION

MPA inhibits the development and maturation of repair tissue at 42 days and incites potential long-term (180 days) detrimental synovial membrane inflammation. Furthermore, a single dose of MPA does not cause long-term detrimental effects (180 days) in quality of repair-tissue.

Temperature imaging in a supersonic free jet of combustion gases with two-line OH fluorescence

Temperature measurements were performed in a shock-tunnel-generated free jet of hydrogen/oxygen reaction products diluted in argon with a nonsimultaneous, two-excitation-line planar laser-induced fluorescence technique with the hydroxyl radical (OH) as a tracer. Single-shot images were obtained with broadband excitation of isolated transitions in the A(2)Σ(+) ? X(2)Π(1, 0) band of OH near 282 nm, with broadband, temporally integrated detection of the resulting nonresonant emission. A measurement of the fluorescence lifetime in the free jet showed no variation with excited rotational level, allowing the rotational temperature to be obtained from the ratio of single-shot images with laser excitation of different rovibronic transitions.

Site-specific proteoglycan characteristics of third carpal articular cartilage in exercised and nonexercised horses

The relevance of site and the influence of exercise on third carpal articular cartilage proteoglycan (PG) were assessed in 16 horses. Six horses were exercised (exercised group) for 30 minutes, 3 times/wk, for 6 weeks. The other 10 horses (nonexercised group) were housed in box stalls for the same 6-week period. At week 6, articular cartilage from the proximal surface of the right third carpal bone was harvested and cultured with radioactive sulfate to label newly synthesized PG. Endogenous PG was measured by use of a uronic acid assay. Newly synthesized and endogenous PG were characterized by use of Sepharose CL-2B chromatography, composite gel electrophoresis, and/or immunoblot analysis with monoclonal antibody 1C6 directed against the hyaluronic acid-binding region on PG. There was a significant (P = 0.0002) effect of exercise, but not site, on newly synthesized PG, which was increased in the exercised horses, compared with the nonexercised horses at the end of the 6-week study period. The increase in newly synthesized PG was not reflected in the existing cartilage matrix as there was no significant difference between groups in endogenous PG. However, there was a significant (P = 0.01) effect of site on endogenous PG, with the nest of sites located in the palmar aspect of the radial facet containing a greater concentration of endogenous PG than the nests of sites located on the dorsal aspect of the radial facet or all sites on the intermediate facet. Most newly synthesized PG in both groups consisted of hydrodynamically small PG monomers. However, there was a change in the profile of newly synthesized PG at some sites in the exercised horses to include an early elution peak on Sepharose CL-2B, which may contain aggregating PG. All sites in both groups contained a diverse population of endogenous large and small PG on toluidine blue-stained composite gels that reacted with monoclonal antibody 1C6, indicating the potential to bind to hyaluronic acid.

Biomechanical properties of third carpal articular cartilage in exercised and nonexercised horses

The relevance of site and exercise on the biomechanical properties of the articular cartilage from the equine third carpal bone were assessed by creep indentation testing. Six horses were exercised for 30 minutes three times weekly. Another six horses were housed in box stalls and were not exercised. At the conclusion of the study, one third carpal bone from each horse was harvested and the KLM biphasic material properties of cartilage were determined at 12 sites. There was a significant (p < 0.01) effect of site but not exercise on the cartilage aggregate modulus, which was significantly lower for sites on the dorsal aspect of the radial facet and for all sites on the intermediate facet as compared with sites on the palmar aspect of the radial facet of the third carpal bone. Exercise significantly increased the permeability constant at all sites when compared with the nonexercised group, but there was no difference between sites within groups. Exercise also significantly increased Poisson's ratio, but only at sites located on the palmar aspect of the radial facet. In general, both site and exercise influence the biomechanical behavior of third carpal articular cartilage. Inherent differences in cartilage biomechanical properties within a joint correlate with the location specificity of cartilaginous lesions in the equine midcarpal joint.

Assessment of glycosaminoglycan concentration in equine synovial fluid as a marker of joint disease

A modification of a colorimetric assay was used to determine synovial fluid total and individual sulphated-glycosaminoglycan concentration in various clinical presentations of joint disease in horses. Concentrations of synovial fluid and serum sulphated-glycosaminoglycan (GAG) were measured by the 1,9-dimethylmethylene blue (DMMB) dye assay in normal horses (n = 49), horses with acute (n = 26) or chronic (n = 27) joint disease (defined by clinical, radiographic, and clinicopathological parameters), and horses with cartilaginous lesions at diagnostic arthroscopy, but with normal radiographs and synovial fluid (n = 9). Horses with acute joint disease were subdivided into moderate acute (n = 21) and severe acute (n = 5) joint disease on the basis of synovial fluid analysis and clinical examination. Horses with chronic joint disease were subdivided into mild chronic (n = 9), moderate chronic (n = 10), and severe chronic (n = 8) joint disease on the basis of synovial fluid analysis, clinical examination, and radiographic findings. The concentrations of chondroitin sulphate (CS) and keratan sulphate (KS) were analyzed in each sample following sequential enzymatic digestion of the sample with chondroitinase or keratanase. In addition, the concentration of hyaluronate (HA) in each sample was determined by a colorimetric assay following digestion of the sample with microbial hyaluronidase.(ABSTRACT TRUNCATED AT 250 WORDS)