Deterioration of polyamino acid-coated alginate microcapsules in vivo

The implantation of immuno-isolated recombinant cell lines secreting a therapeutic protein in alginate microcapsules presents an alternative approach to gene therapy. Its clinical efficacy has recently been demonstrated in treating several genetic diseases in murine models. However, its application to humans will depend on the long-term structural stability of the microcapsules. Based on previous implantations in canines, it appears that survival of alginate-poly-L-lysine-alginate microcapsules in such large animals is short-lived. This article reports on the biological factors that may have contributed to the degradation of these microcapsules after implantation in dogs. Alginate microcapsules coated with poly-L-lysine or poly-L-arginine were implanted in subcutaneous or intraperitoneal sites. The retrieved microcapsules showed a loss of mechanical stability, as measured by resistance to osmotic stress. The polyamino acid coats were rendered fragile and easily lost, particularly when poly-L-lysine was used for coating and the intraperitoneal site was used for implantation. Various plasma proteins were associated with the retrieved microcapsules and identified with western blotting to include Factor XI, Factor XII, prekallikrein, HMWK, fibrinogen, plasminogen, ATIII, transferrin, alpha-1-antitrypsin, fibronectin, IgG, alpha-2-macroglobulin, vitronectin, prothrombin, apolipoprotein A1, and particularly albumin, a major Ca-transporting plasma protein. Complement proteins (C3, Factor B, Factor H, Factor I) and C3 activation fragments were detected. Release of the amino acids from the microcapsule polyamino acid coats was observed after incubation with plasma. indicating the occurrence of proteolytic degradation. Hence, the loss of long-term stability of the polyamino acid-coated alginate microcapsules is associated with activation of the complement system, degradation of the polyamino acid coating, and destabilization of the alginate core matrix, probably through loss of calcium-mediated ionic cross-linking of the guluronic acid polymers in the alginate. These destructive forces may be slightly mitigated by using poly-L-arginine instead of poly-L-lysine for coating and by implanting in a subcutaneous instead of an intraperitoneal site. However, the long-term stability of such devices may require significant improvements in the microcapsule polymer chemistry to withstand such biological impediments.

DIFFERENTIAL EXPRESSION OF MAMMALIAN OR VIRAL PROMOTER–DRIVEN GENE IN ADHERENT VERSUS SUSPENSION CELLS

Although expression vectors using viral and mammalian promoters constitutively express genes of interest in adherent cells, few studies have examined whether the function of these vectors in suspended cells, such as in over-agar or soft agar assay (an in vitro cell transformation assay), is as robust as when they are in adherent cells. The selection of appropriate expression vector to optimally express genes in suspended cells would be useful in determining whether these genes play a critical role in maintaining colony formation or cell transformation. To compare promoter-driven expression vector function in adherent versus suspension cells, we performed transient transfection assays using viral (simian virus 40 [SV40] and cytomegalovirus [CMV]) and mammalian (beta-actin) promoters fused to luciferase or beta-galactosidase reporter gene. Over-agar assay was used to suspend cells on top of agar, which allowed cell retrieval and analysis. We found that beta-actin and SV40 promoters exhibited suppressed gene expression of 70 and 56%, respectively, in cells suspended on agar compared with those attached on plates. The suppressed response by the exogenous beta-actin promoter in suspension was consistent with the response of the endogenous beta-actin promoter activity because the steady-state level of beta-actin messenger ribonucleic acid in suspended cells was significantly reduced by 50% relative to that expressed in attached cells. In contrast to SV40 promoter, CMV promoter activity was not decreased in cells suspended in over-agar when compared with adherent cells. These studies show that regardless of mammalian or viral vectors, one cannot assume that all expression vectors behave similarly in both suspension and adherent state.

The differences in health outcomes between Web-based and paper-based implementation of a clinical pathway for radical nephrectomy

OBJECTIVE

To evaluate the effects of a web-based clinical pathway (WCP) for radical nephrectomy on patient care, and to compare the effects with those of a paper-based clinical pathway (PCP).

PATIENTS AND METHODS

Patients with renal cell carcinoma and who underwent radical nephrectomy were enrolled into the study. The results of using the WCP for radical nephrectomy from July 2000 to August 2001 were compared with those using the PCP between May 1999 and June 2000. The mean hospital stay, average admission charges, six quality indicators, and the advantages of the WCP were determined.

RESULTS

Using a WCP for radical nephrectomy reduced the hospital stay and admission charges by as much as the PCP. A similar number of patients had variances from the WCP as with the PCP (P = 0.407), but the number of undetected variances and the variance detection time in the WCP were significantly less (P = 0.0193 and 0.0162). Implementing a WCP also improved the quality of care by as much as a PCP.

CONCLUSIONS

Using a WCP for radical nephrectomy can improve health outcomes by reducing the hospital stay and admission charges, and by improving the quality of care by as much as a PCP. Furthermore, the WCP was more accurate and faster than the PCP in detecting variances.

Promotion of malignant astrocytoma cell migration by osteopontin expressed in the normal brain: differences in integrin signaling during cell adhesion to osteopontin versus vitronectin

The extracellular matrix of the normal adult brain lacks expression of most of the adhesive glycoproteins that are known to promote cell attachment, and it has been thought that the malignant invasion of astrocytoma tumor is mediated primarily by remodeling of the matrix by the tumor cells. It has been reported, however, that normal brain neuropil does contain a protein(s) that promotes cell attachment. Therefore, we explored the possibility that the cell attachment protein, osteopontin, is expressed in the normal human brain. Here, we report that osteopontin is expressed in the cortical gray and white matter of normal adult brain, with the levels of osteopontin expression being equivalent to those in malignant astrocytic tumor biopsies as assessed by Western blot analysis. Immunoblotting identified osteopontin polypeptides with relative molecular weights of 60- and 65-kDa in normal brain white matter and in astrocytic tumors, with an additional 70-kDa polypeptide being identified in normal cortical gray matter and in some astrocytic tumors. Recombinant osteopontin was found to promote attachment of U-251MG human malignant astrocytoma cells in a process that was inhibited by anti-integrin monoclonal antibodies anti-alphavbeta3 (75%), anti-alphavbeta5 (80%), and anti-alpha5 (40%). On attachment, integrins alphavbeta5 and alphavbeta3 localized to focal adhesions, and there was an alteration in cell morphology with the formation of lamellae-like processes. The attachment was associated with activation of Rac in a slow and prolonged fashion and rapid activation of Rho. Similarly, integrins alphavbeta5 and alphavbeta3 localized to focal adhesions on attachment of the U-251MG cells to vitronectin, but on this substrate, the cells assumed a spread and flat morphology, and there was rapid activation of both Rac and Rho. Extracts of normal brain white matter were capable of promoting haptotactic migration, and this response was inhibitable by monoclonal antibodies anti-alphavbeta3 and anti-alpha5. Depletion of the osteopontin in these extracts abrogated the haptotactic response significantly (50%). These data indicate that the cell attachment protein, osteopontin, is expressed in the normal adult brain and that it has the potential to promote malignant astrocytoma cell invasion.

Improvement of practice performance in urological surgery via clinical pathway implementation

The purpose of this study was to compare performance measurements to evaluate the effects of clinical pathway implementation on improving practice performances in urology. Since April 1997, a total of 18 clinical pathways have been created in the urology department. Of these clinical pathways, six were implemented for endoscopic surgery, and four and eight were for minor and major surgery, respectively. Eight prominent performance measurements, which were identified as representative indicators of the practice performances, were selected in endoscopic surgery, five in minor surgery, and 11 in major surgery. Between April 1997 and March 1999, 2,883 consecutive patients, who underwent endoscopic surgery, minor surgery, and major surgery, were evaluated herein. The treatment results for patients in the first and second years of clinical pathway implementation were compared to those from the year preceding the implementation. In endoscopic surgery, five of the eight performance measurements improved significantly in the first year of implementation. Notably, three of the five improved performances continued to improve in the second year. Similarly, in minor surgery, four of the five performance measurements improved significantly following 2 years. Finally, in major urological surgery, six of the 11 performance measurements also improved significantly after 1 year; four of which continued to improve during the second year. Therefore, we conclude that patient care, which is based on the implementation of clinical pathways, can improve practice performances and facilitate medical care.

Novel protein kinase C isoforms and mitogen-activated kinase kinase mediate phorbol ester-induced osteopontin expression

BACKGROUND AND AIMS

The expression of osteopontin (OPN), a protein postulated to play a role in tumorigenesis, is induced by the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) in vivo and in the in vitro initiation-promotion skin carcinogenesis model (JB6 cells). Although TPA-induced OPN expression in JB6 cells has been suggested to involve protein kinase C (PKC), the PKC isoforms and the downstream pathway mediating OPN expression have not been extensively studied.

METHODS

Using the JB6 cell model, we determined the involvement of PKC isoforms, mitogen-activated protein kinase kinase (MAPK kinase/MEK) and MAPK in TPA-induced OPN expression using inhibitors specific to PKC isoforms and MEK and performing Northern blot analyses. Western blot analyses of cells treated with specific inhibitors were also performed to determine whether PKC isoforms or MEK were involved in activation of MAPK.

KEY RESULTS

TPA increased the steady-state level of OPN mRNA as early as 2-4h and this expression persisted for at least 4 days. TPA induction of OPN expression in JB6 cells is mediated through PKC epsilon and PKC delta, which also mediated the phosphorylation of MAPK. Additionally, inhibition of MEK activity, which activates MAPK, attenuated TPA-induced OPN expression. These findings suggest that activation of MAPK is important in mediating OPN expression.

CONCLUSION

TPA-induced steady-state OPN mRNA expression in mouse JB6 cells involves the activation of MAPK mediated through PKC epsilon and/or PKC delta.

Treatment of hemophilia B in mice with nonautologous somatic gene therapeutics

The implantation of nonautologous cells encapsulated in immunoprotective microcapsules provides an alternative nonviral method for gene therapy. This strategy was successful in reversing the disease phenotypes of dwarfism and a lysosomal storage disease, mucopolysaccharidosis VII, in murine models. In this article we implanted transgenic hemophilic B mice with microcapsules enclosing factor IX-secreting C2C12 myoblasts to study the clinical potential of this approach in the treatment of hemophilia. Treated mice showed increased plasma factor IX levels as high as 28 ng of human factor IX per milliliter of plasma and decreased activated thromboplastin times (reduced by 20% to 29%). However, the level of factor IX decreased to baseline levels by day 7, coinciding with emergence of anti-human factor IX antibody, the titer of which increased greater than 10-fold by day 28. Monoclonal anti-CD4 antibodies were used to deplete CD4+ T cells to suppress the immune response against the recombinant factor IX. In the treated hemophilic mice, the anti-factor IX antibody response was totally suppressed to beyond day 28 accompanied by a significant decrease in activated thromboplastin time compared with that seen in untreated hemophilic mice. When the microcapsules were recovered from the intraperitoneal cavity after 38 days of implantation, the encapsulated cells continued to secrete factor IX at preimplantation levels, but both cell viability and microcapsule mechanical stability were reduced. Hence although the polymer chemistry of the microcapsules and cell viability may need to be improved for long-term delivery, nonautologous gene therapy with microencapsulated cells has been shown to be effective, at least for the short-term, in alleviating the hemophilic hemostatic anomaly. Coadministration of an immunosuppressant is effective in inhibiting antibody development against the delivered factor IX and should be considered for recipients at risk of inhibitor development.

Hydroxylapatite binds more serum proteins, purified integrins, and osteoblast precursor cells than titanium or steel

The implant material hydroxylapatite (HA) has been shown in numerous studies to be highly biocompatible and to osseointegrate well with existing bone; however, the molecular mechanisms at work behind this osseointegration remain largely unexplored. One possibility is that the implant, exposed to the patient's blood during surgery, adsorbs known cell adhesive proteins such as fibronectin and vitronectin from the serum. Osteoblast precursors could then adhere to these proteins through integrin-mediated mechanisms. In the present study, we have used a quantitative ELISA assay to test the hypothesis that hydroxylapatite will adsorb more fibronectin and vitronectin from serum than two commonly used hard-tissue materials, commercially pure titanium, and 316L stainless steel. We further used the ELISA, as well as a standard cell adhesion assay, to test the hypothesis that increased protein adsorption will lead to better binding of purified integrins alpha5beta1 and alpha(v)beta3 and osteoblast precursor cells to the HA than to the metals. Our results show that fibronectin, vitronectin, alpha5beta1, alpha(v)beta3, and osteoblast precursor cells do indeed bind better to HA than to the metals, suggesting that improved integrin-mediated cell binding may be one of the mechanisms leading to better clinical bone integration with HA-coated implants.

Immuno-isolation in oncology--a mini-review

Immuno-isolation provides a potentially safe and effective method of delivering recombinant therapeutic molecules. Its application as a drug-delivery platform for the treatment of cancer has shown promising developments recently. This review will summarize the principle and current progress of this novel therapy paradigm in oncology. In this approach, a non-autologous cell line is genetically modified to secrete a recombinant product with potential for tumor suppression. Such a cell line may be implanted without graft rejection into all patients with similar neoplastic disease. The immune protection is conferred by enclosure within immuno-isolating devices such as microcapsules whose permeability would allow passage of smaller molecules such as oxygen, nutrients and waste products as well as the desired therapeutic transgene product. However, large immune mediators such as complement, macrophages and lymphocytes responsible for graft rejection would be excluded. In this review, we will consider how this technology may be applied as a novel genetic tool for cancer treatment to deliver antibodies, cytokines, enzymes and growth factors for treatment of various types of cancer. These molecules can be delivered at low constitutive levels, thereby permitting long-term systemic delivery, maintaining biological activity over extended periods, and eliminating the costs of product purification. The current success of this strategy in cancer treatment will be reviewed in in vitro systems, in animal models of cancer, and in human clinical trials.

Analysis of large-volume DNA markers and polymerase chain reaction products by capillary electrophoresis in the presence of electroosmotic flow

We have demonstrated on-line concentration and separation of DNA in the presence of electroosmotic flow (EOF) using poly(ethylene oxide) (PEO) solutions. After injecting large-volumes DNA samples, PEO solutions entered a capillary filled with 400 mM Tris-borate (TB) buffers by EOF and acted as sieving matrices. DNA fragments stacked between the sample zone and PEO solutions. Because sample matrixes affected PEO adsorption on the capillary wall, leading to changes in EOF, migration time, concentration, and resolving power varied with the injection length. When injecting phiX174 RF DNA-HaeIII digest prepared in 5 mM Tris-HCl buffer, pH 7.0, at 250 V/cm, peak height increased linearly as a function of injection volume up to 0.9 microl (injection time 150 s). The sensitivity improvement was 100-fold compare to that injected at 25 V/cm for 10 s (0.006 microl). When injecting 1.54 microl of GeneScan 1000 ROX, the sensitivity improvement was 265-fold. The sensitivity improvement was 40-fold when injecting 0.17 microl DNA sample containing pBR 322/HaeIII, pBR 328/BglI, and pBR 328/HinfI digests prepared in phosphate-buffered saline. This method allows the analysis of polymerase chain reaction (PCR) products amplified after 17 cycles when injecting 0.32 microl (at 30 cm height for 300 s). The total analysis time was shorter (91.6 min) than that (119.6 min) obtained from injecting PCR products after 32 cycles for 10 s.

Posthumous reproduction in a human immunodeficiency virus-discordant couple

A human immunodeficiency virus-discordant couple failed to conceive through in vitro fertilization and intracytoplasmic sperm injection of cryopreserved semen banked by the human immunodeficiency virus-positive partner. The husband subsequently had acquired immunodeficiency syndrome and died. The subsequent transfer of cryopreserved embryos resulted in pregnancy. Both mother and child are human immunodeficiency virus negative.

Omega-3 fatty acids decrease protein kinase expression in human breast cancer cells

We report that 5-day exposure to physiological concentrations of eicosapentaenoic and docosahexaenoic acids resulted in a strong decrease in expression of the RIalpha regulatory subunit of protein kinase A and the PKC-alpha isozyme of protein kinase C in the human breast cancer cell line MDA-MB-231.

Glutamine utilization in activated lymphocytes from rats receiving endotoxin

BACKGROUND

A beneficial effect of supplemental glutamine for lymphocyte function in patients under metabolic stress has been suggested. Nevertheless, it is not clear how glutamine is used by lymphocytes when under stress. This time course study investigated the effect of endotoxin-induced stress on in vitro glutamine utilization and glutamine-dependent proliferation of activated lymphocytes.

METHODS

Metabolic stress was modeled by intraperitoneal (ip) administration of endotoxin (5 mg/kg body wt) to rats. Control animals were injected with sterile saline. Cervical lymph node lymphocytes collected from animals 6, 12, 24, and 48 h following injection were activated with concanavalin A. Proliferation of these activated lymphocytes in the presence of 0.1-2 mM glutamine was determined. The glutamine utilization rate and glutaminase activity in the activated lymphocytes were also determined.

RESULTS

The proliferation rate of lymphocytes was not affected by ip administration of endotoxin 6 h following the insult, however, 12, 24, and 48 h following the insult, the maximal response was suppressed (P < 0.05). In addition, at 12, 24, and 48 h, the concentration of glutamine for the maximal response of lymphocytes was lower than that for the control group (P < 0.05). Throughout the investigation period, both the glutamine utilization rate and glutaminase activity in the activated lymphocytes were decreased time-dependently.

CONCLUSION

The present study demonstrates that glutamine utilization by lymphocytes under a mitogenic challenge in vitro is significantly decreased in the late period after endotoxin injection. This is at least partly due to decreased glutaminase activity and is associated with decreased proliferation rate of mitogen-activated lymphocytes.

Osmotic pressure test: a simple, quantitative method to assess the mechanical stability of alginate microcapsules

Implantation of microencapsulated, nonautologous cells and tissues is an effective method to deliver therapeutic proteins in vivo. Its success depends on the maintenance of the immunoisolating barrier provided by the microcapsule. Thus, one goal in the development of this technology is to create mechanically stable microcapsules. We have developed an osmotic pressure test to quantify the strength of microcapsules by exposing alginate microcapsules to a graded series of hypotonic solutions and quantifying the percentage of broken microcapsules. The test was validated by confirming the relative strengths of different types of alginate capsules, previously known from implantation in dogs to have differing mechanical stability in vivo. Thus, solid alginate microcapsules crosslinked with Ba(2+) were shown to be stronger than those crosslinked with Ca(2+), which in turn were shown to be stronger than the corresponding hollow alginate microcapsules. The incorporation of cells was demonstrated to reduce the mechanical stability of the microcapsules significantly. Hence, this test provides a simple and quantitative method for rapidly determining the strength of a large number of microcapsules. Thus, it is suitable for monitoring the mechanical stability of various types of microcapsules, predicting the performance of microcapsules in vivo, and for quality control of microcapsules during scale-up productions.

Improvement of health outcomes after continued implementation of a clinical pathway for radical nephrectomy

The clinical pathway is an important tool for outcome management. We evaluated the overall effects of the continued implementation of a clinical pathway for radical nephrectomy on the length of hospital stay, admission charges, and the quality of medical care. The data obtained from the second-year implementation (group 3) of the clinical pathway were compared with the data from the first-year implementation (group 2) and the year preceding implementation (group 1). Thirty-seven consecutive patients with renal cell carcinoma underwent radical nephrectomy in group 1, 47 in group 2, and 55 in group 3; all were enrolled in this study. The length of hospital stay, average admission charges, and 8 quality indicators were measured in these patients. We also evaluated the variances in the implementation of the clinical pathway. The mean length of stay decreased by 14.0% (P = 0.0048) in group 2, and by 15.8% (P= 0.0014) in group 3, when compared to group 1. The total admission charges significantly decreased by 19.0% (P = 0.001) in group 2, and by 27.9% (P < 0.0001) in group 3, compared to the charges for group 1. A continued decrease in charges for operation and anesthesia, laboratory, pharmacy, and others were found 2 years after implementation of the clinical pathway. Among the 8 quality indicators, 2 were continuously improved in the second-year implementation of the clinical pathway, 2 were improved significantly in the second-year implementation only, and 4 showed no significant change at all. Variances from the clinical pathway decreased significantly after continued implementation. Continued implementation of the clinical pathway for radical nephrectomy can improve a physician's practice continuously by decreasing the length of hospital stay, admission charges, and variances, and by improving quality. However, the improved results after implementation of the clinical pathway should be maintained carefully to assure good health care.

Somatic gene therapy for a neurodegenerative disease using microencapsulated recombinant cells

Neurodegenerative diseases caused by lysosomal enzyme deficiencies are catastrophic illnesses with both peripheral organ and central nervous system abnormalities. The mucopolysaccharidosis type VII mouse with beta-glucuronidase deficiency was used to develop an alternate approach to gene therapy, in which a "universal" cell line engineered to secrete the missing enzyme is implanted directly into all recipients requiring the same enzyme replacement. The cells, though nonautologous, were rendered immunologically tolerable by protection in immunoisolating microcapsules. Since the blood-brain barrier impedes the passage of large molecules such as beta-glucuronidase, encapsulated cells producing beta-glucuronidase were introduced directly into the lateral ventricles of the brain. Based on this strategy, beta-glucuronidase was delivered throughout most of the central nervous system, reversing the histological pathology and reducing the previously elevated levels of lysosomal enzymes beta-hexosaminidase and alpha-galactosidase. The effectiveness of this approach was further demonstrated with improvements in the mutant circadian rhythm behavioral abnormalities. Compared to wild-type and heterozygous mice, the mutant mice had an unstable periodicity, fragmented activity, and a sixfold reduction in wheel running activity. After treatment, the mutant behavioral abnormalities were significantly improved with a more stable periodicity and a less fragmented pattern of activity. While the overall total activity level did not increase in the treated mutants, it did not show the deterioration observed in the sham-treated as well as in the untreated mutant mice. Hence, this alternative cell-based gene therapy demonstrates biochemical, histological, and behavioral efficacy and provides a potentially cost-effective and nonviral treatment applicable to all lysosomal storage diseases with neurological deficits.

Treatment of a lysosomal storage disease, mucopolysaccharidosis VII, with microencapsulated recombinant cells

Most lysosomal enzyme deficiencies are catastrophic illnesses with no generally available treatments. We have used the beta-glucuronidase-deficient mouse model of mucopolysaccharidosis type VII (MPS VII) to develop an alternative approach to therapy. A "universal" cell line engineered to secrete the missing enzyme is implanted in all recipients requiring the same enzyme replacement. The cells, although nonautologous, are rendered immunologically tolerant by encapsulation in microcapsules that provide protection from immune mediators. Using this strategy, we injected beta-glucuronidase-secreting fibroblasts enclosed in alginate microcapsules into mutant MPS VII mice. After 24 hr, beta-glucuronidase activity was detected in the plasma, reaching 66% of physiological levels by 2 weeks postimplantation. Significant beta-glucuronidase activity was detected in liver and spleen for the duration of the 8-week experiment. Concomitantly, the intralysosomal accumulation of undegraded glycosaminoglycans was dramatically reduced in liver and spleen tissue sections and urinary glycosaminoglycan content was reduced to normal levels. Elevated secondary lysosomal enzymes beta-hexosaminidase and alpha-galactosidase were also reduced. However, implanted mutant MPS VII mice developed antibodies against the murine beta-glucuronidase, demonstrating a potential obstacle in patients with a null mutation who react against the replaced enzyme as a foreign antigen. The antibody response was transiently circumvented with a single treatment of purified anti-CD4 antibody coadministered with the microcapsules. This resulted in increased levels and duration of beta-glucuronidase delivery. Similarly, treated heterozygous mice maintained elevated levels of beta-glucuronidase and did not develop antibodies. This novel cell-based therapy demonstrates a potentially cost-effective and nonviral treatment applicable to all lysosomal storage diseases.

Improvement of medical care quality after implementation of a clinical path monitoring program for transurethral prostatectomy patients

OBJECTIVES

The purpose of this study was to determine the effect on quality of care through the implementation of a clinical path for patients receiving transurethral prostatectomy.

METHODS

We selected ten quality indicators with important clinical relevance as representative elements of the clinical path. These quality indicators were monitored during the entire hospitalization period of 100 consecutive patients who received transurethral prostatectomy. Monitoring data obtained from these patients were compared to data from 100 patients who received transurethral prostatectomy prior to implementation of the clinical path. Data was assessed to determine the relationship between quality indicators and management processes.

RESULTS

Implementation of the clinical path for transurethral prostatectomy significantly decreased the percent of patients with incomplete preoperative tests on admission day, the duration of intravenous antibiotics administration, the percent of patients who required acute pain management postoperatively, the percent of patients who received postoperative bladder irrigation with normal saline and the percent of patients who had their Foley catheter removed after postoperative day 2. Three of the quality indicators had a significant relationship with management processes and may have directly affected the total admission charges.

CONCLUSIONS

To evaluate the effect of the transurethral prostatectomy clinical path implementation on the quality of medical care, we compared ten quality indicators before and after implementation of this path. We concluded that implementation of the clinical path resulted in a statistically significant improvement in the quality of medical care.

Adrenal ganglioneuroma: report of five cases

Adrenal ganglioneuromas are rare tumors originating from the neural crest tissue of the sympathetic nervous system. The clinical presentation of most patients is asymptomatic, and most of these tumors are hormone silent. Usually the tumor is detected incidentally by abdominal imaging studies for unrelated reasons. Herein, we review our cases of adrenal ganglioneuroma over the past 20 years. All patients diagnosed with primary adrenal ganglioneuroma between 1979 and 1999 were reviewed. There were 5 cases of pathologically confirmed adrenal ganglioneuroma. All patients underwent surgical excision of the adrenal tumors. The mean age of the 5 patients (3 women and 2 men) was 27 years (range, 11 to 45 years). The average diameter of the tumor was 8.2 cm (range, 6 to 10 cm). The mean follow-up period was 33.6 months (range, 3 to 92 months). One case involved mesenteric lymph nodes. This patient had persistent hypertension following the operation, but no evidence of tumor recurrence was noted over the 7-year follow-up period. The prognosis was excellent after surgical excision in our series. Awareness of this rare entity may add to the differential diagnoses of adrenal masses preoperatively.

Canine models for human genetic neurodegenerative diseases

1. Canine models of human neurodegenerative disorders are uncommon. However, the similarity between canines and humans in body sizes and physiology provides an exceptional opportunity to use these models to study human diseases. 2. The authors will present a review on the neurological deficits that have been observed in canine models of genetic neurodegenerative diseases, and summarize the current gene therapy treatments being developed for some of these conditions.

Expression of osteopontin messenger RNA and protein in rheumatoid arthritis: effects of osteopontin on the release of collagenase 1 from articular chondrocytes and synovial fibroblasts

OBJECTIVE

Osteopontin (OPN) is an extracellular matrix protein that has been implicated in the interactions between tumor cells and host matrix, including those involved in invasion and spread of tumor cells. Because joint destruction in rheumatoid arthritis (RA) is mediated by the invasive growth of synovial tissue through its attachment to cartilage, we examined the expression of OPN in the synovia of patients with RA and the effect of OPN on the production of collagenase 1 in rheumatoid synovial fibroblasts and articular chondrocytes.

METHODS

The expression of OPN messenger RNA (mRNA) and protein in synovia from 10 RA patients was examined by in situ hybridization and immunohistochemistry. Synovial fibroblasts from RA patients and articular chondrocytes from patients without joint disease were cultured in the presence of various concentrations of OPN, and levels of collagenase 1 in the culture supernatants were measured by enzyme-linked immunosorbent assay.

RESULTS

The expression of OPN mRNA and protein was observed in 9 of 10 specimens obtained from patients with RA. OPN was expressed in the synovial lining and sublining layer and at the interface of cartilage and invading synovium. Double labeling revealed that the majority of OPN-expressing cells were positive for the fibroblast-specific enzyme prolyl 4-hydroxylase and negative for the macrophage marker CD68, while only a few, single OPN-expressing cells were positive for CD68 at sites of synovial invasion into cartilage. OPN staining was not observed in lymphocytic infiltrates or leukocyte common antigen (CD45)-positive cells. Three of 3 cultures of human articular chondrocytes secreted detectable basal amounts of collagenase, with a dose-dependent increase upon OPN stimulation, while synovial fibroblast cultures produced much lower levels of collagenase, with only 2 of 4 fibroblast cultures responding in a dose-dependent manner.

CONCLUSION

These findings suggest that OPN produced by synovial fibroblasts in the synovial lining layer and at sites of cartilage invasion not only mediates attachment of these cells to cartilage, but also contributes to matrix degradation in RA by stimulating the secretion of collagenase 1 in articular chondrocytes.

Delivery of recombinant product from subcutaneous implants of encapsulated recombinant cells in canines

Delivering recombinant therapeutic proteins from a universal microencapsulated cell line is an alternate method for gene therapy. It has proved effective in the treatment of several murine models of human genetic diseases. However, in scaling up to large animal models, intraperitoneal Implantations of these microcapsules in canines were associated with excessive Inflammatory response and rapid degradation. We now show that subcutaneous implantation of microencapsulated cells in canines is effective in delivering recombinant product systemically for extended periods, provides a surgically benign site, leads to less inflammatory response, and permits longer-term survival of microcapsules. Allogeneic MDCK cells engineered to secrete human growth hormone (hGH) were microencapsulated in alginate-poly-L-lysine-alginate and implanted subcutaneously. Systemic delivery of hGH was evident within 4 hours and peaked by day 1 after implantation in all dogs. The gradual decline of hGH in the circulation in the first 2 weeks coincided with the development of anti-hGH antibodies by day 11. The high titer persisted for more than 1 month, demonstrating indirectly the persistent delivery of hGH. Microcapsules retrieved from the subcutaneous implant maintained their structure throughout the experiment and were free of host cellular adhesions. The mechanical integrity of the subcutaneously implanted microcapsules also appeared superior to that of the intraperitoneal implant. Hence the subcutaneously implanted microcapsules required minimal surgical intervention and led to a low level of inflammatory response, and the implant survived for at least 1 month, thus demonstrating the feasibility of systemic delivery of recombinant products via subcutaneous implantation in large animals.