Image-based biomimetic approach to reconstruction of the temporomandibular joint

This article will present an image-based approach to the designing and manufacturing of biomimetic tissue engineered temporomandibular (TMJ) condylar prosthesis. Our vision of a tissue-engineered TMJ prosthesis utilizes a 3-D designed and manufactured biodegradable scaffold shaped similar to a condylar head and neck, i.e. a condylar-ramus unit (CRU). The fabricated CRU scaffold can be constructed with a specific intra-architectural design such that it will enhance the formation of tissue from implanted cells placed within its interstices. These biologic cues could influence scaffold-implanted mesenchymal stem cells (MSC) or bone marrow stromal cells (BMSC) to form a fibrocartilaginous joint surface, or cap, on top of a bony strut, similar to a costochondral rib graft (CCRG), which could be fixed to the mandibular ramus. This new approach to tissue engineering a TMJ would be advantageous because of its patient site-specific anatomical configuration as well as its potential ability to adapt to the loading forces placed on it during function.

Hydroxyapatite implants with designed internal architecture

Porous hydroxyapatite (HA) has been used as a bone graft material in the clinics for decades. Traditionally, the pores in these HAs are either obtained from the coralline exoskeletal patterns or from the embedded organic particles in the starting HA powder. Both processes offer very limited control on the pore structure. A new method for manufacturing porous HA with designed pore channels has been developed. This method is essentially a lost-mold technique with negative molds made with Stereolithography and a highly loaded curable HA suspension as the ceramic carrier. Implants with designed channels and connection patterns were first generated from a Computer-Aided-Design (CAD) software and Computer Tomography (CT) data. The negative images of the designs were used to build the molds on a stereolithography apparatus with epoxy resins. A 40 vol% HA suspension in propoxylated neopentyl glycol diacrylate (PNPGDA) and iso-bornyl acrylate (IBA) was formulated. HA suspension was cast into the epoxy molds and cured into solid at 85 degrees C. The molds and acrylate binders were removed by pyrolysis, followed by HA green body sintering. With this method, implants with six different channel designs were built successfully and the designed channels were reproduced in the sintered HA implants. The channels created in the sintered HA implants were between 366 microm and 968 microm in diameter with standard deviations of 50 microm or less. The porosity created by the channels were between 26% and 52%. The results show that HA implants with designed connection pattern and well controlled channel size can be built with the technique developed in this study.

An image-based approach for designing and manufacturing craniofacial scaffolds

Bone tissue engineering (BTE), which combines biomaterial scaffolds with biologically active factors, holds tremendous promise for reconstructing craniofacial defects. A significant challenge in craniofacial reconstructive BTE applications is the complex patient-specific geometry that must be reconstructed. In this paper, we present an image-based approach for designing and manufacturing patient-specific craniofacial biomaterial scaffolds directly from CT or MRI data. In this approach, voxel density distribution is used to define scaffold topology. The scaffold design topology is created using image processing techniques. This voxel density distribution is then converted to data that can be used to drive a Solid Free-Form Fabrication machine to either directly build the scaffold or build a mold for the scaffold. Several preliminary applications for craniofacial surgery, including a mandibular condyle scaffold, an orbital floor scaffold, and a general mandibular defect scaffold, are illustrated. Finally, we show applications to in vivo models.

Plasmin, substilisin-like endoproteases, tissue plasminogen activator, and urokinase plasminogen activator are involved in activation of latent TGF-beta 1 in human seminal plasma

We reported previously that TGF-beta 1 is a major immunosuppressive agent in human seminal plasma. TGF-beta 1 in seminal plasma is so abundant that it may represent the highest physiologic concentration of TGF-beta 1 reported for a biological fluid. The in vitro activation of TGF-beta 1 is detected at acidic pH. The acidic environment of the vagina is suggested as an in vivo physiological condition for the activation of seminal plasma latent TGF-beta 1. The present study demonstrates that Pefabloc [4-(2-aminoethyl)-benzenesulfonyl fluoride AEBSF]-inhibitable serine proteases are involved in the activation of latent TGF-beta 1. Pefabloc inhibits latent TGF-beta 1 activation in a dose- and time-dependent manner. The use of other protease inhibitors and specific antibodies reveals that, in addition to plasmin, substilisin-like endoproteases and tissue- and urokinase-type plasminogen activators participate in the activation of latent TGF-beta 1 in human seminal plasma.

CT-generated porous hydroxyapatite orbital floor prosthesis as a prototype bioimplant

Hydroxyapatite bioceramic was used for the manufacture of an orbital floor prosthesis from spiral CT data acquired transaxially at 1-mm beam collimation, pitch of 1, and 0.2-mm reconstruction intervals. CT data were converted to vector file format for subsequent prosthesis manufacture on a stereo-lithography machine. The orbital floor prosthesis was engrafted onto an acrylic model of the orbit as a qualitative indication of its overall accuracy. High anatomic accuracy was achieved, as determined by visual inspection. Cross-hatching of the vector file data allowed a porous internal architecture of the prosthesis. Refinements in chemical structure of the hydroxyapatite bioceramic are expected to enhance mechanical properties.

Molecular diagnosis of pancreas carcinoma

Cellular protooncogenes, tumor suppressor genes (antioncogenes), and DNA mismatch repair mutators are generally the key molecular genetic biomarkers undergoing alterations during carcinogenesis, i.e., activation of oncogenes, inactivation of tumor suppressors, and DNA mismatch repair gene defects are essential events in cancer causation. In pancreas cancer, high incidence of oncogene K-ras point mutations at the codon 12th is associated with premalignant and malignant transformation. Mutation in p53 tumor suppressor is also detected in pancreas adenocarcinoma. Concurrent loss of p53 and K-ras function may contribute to the clinical aggressiveness of pancreas cancer. Microsatellite instability and DNA mismatch repair defects may represent new mutator phenotype for pancreas carcinogenesis. Mutation of cell cycle regulators, such as inhibitor of CDK4 or p16 tumor suppressor gene, is a new molecular event in pancreas cancer. Mutation of cyclin-dependent kinases also may be involved in pancreas carcinogenesis. Loss or mutation of a new candidate tumor suppressor, DPC4 (deleted in pancreas carcinoma locus 4), is reported in pancreas cancer. The protein products of these gene mutations are potential tumor antigens, thus genotype expression can be detected by phenotype. Most of these emerging molecular genetic biomarkers are associated with regulation of cell growth and recognition, as well as gene expression, and may offer new insight into the cellular precursors to and genesis of pancreas cancer.

Prostate-specific antigen and early detection of prostate cancer

Prostate-specific antigen (PSA) is biochemically a 33-kDa serine protease and is the prototype of tumor marker most useful in investigating basic science and clinical application of prostate cancer. As an immunohistopathological marker, PSA is especially effective in the identification of distant metastatic prostate carcinoma and in the differential diagnosis of poorly differentiated transitional cell carcinomas of the bladder from prostate carcinoma. As a serologic marker, PSA is most useful in staging, monitoring and in early detection of recurrent disease. The greatest value of PSA is as a screening aid along with digital rectal examination for early detection of prostate cancer. PSA-based screening tests have been performed in various regions of the world and have yielded prostate cancer detection rates proportional to that of incidence rates in the countries. Most significantly, PSA detects early nonpalpable prostate cancer. Approximately 85% of the prostate tumors detected through PSA have the clinical features associated with medically important cancer. Further, a majority of the tumors, 70%, are confined to the organ. Although the issues of cost-benefit and increase in ultimate survival rate are still being evaluated in two large-scale randomized national trials, timely and definitive therapies of these potentially lethal tumors can result in high cure rate and improve the quality of patients' life.

All-trans retinoic acid decreases susceptibility of a gastric cancer cell line to lymphokine-activated killer cytotoxicity

All-trans retinoic acid (RA) was previously shown to regulate the growth of gastric cancer cells derived from the cell line SC-M1. This study was designed to investigate the effect of RA on the sensitivity of SC-M1 cells to lymphokine-activated killer (LAK) activity. RA at the concentration range of 0.001-10 microM was shown to induce SC-M1 cells to exhibit resistance to LAK activity in a dose-dependent manner. A kinetics study indicated that a significantly increased resistance was detected after 2 days of co-culturing SC-M1 cells with RA and reached a maximum after 6 days of culture. Similar results were obtained from two other cancer cell lines: promyelocytic leukaemia HL-60 and hepatic cancer Hep 3B. A binding assay demonstrated that the binding efficacy between target SC-M1 cells and effector LAK cells was not altered by RA. Flow cytometric analyses revealed that RA exhibited no effect on the expression of cell surface molecules, including HLA class I and class II antigens, intercellular adhesion molecule-1 and -2, and lymphocyte function antigen-3. Cell cycle analysis revealed that culture of SC-M1 cells with RA resulted in an increase in G0/G1 phase and a decrease in S phase, accompanied by a decrease in cyclin A and cyclin B1 mRNA as determined by Northern blot analysis. Additionally, RA was shown to enhance the expression of retinoic acid receptor alpha (RAR alpha) in SC-M1 cells, and to have no effect on the expression of RARbeta or RARgamma. Taken together, these results indicate that RA can significantly increase gastric cancer cells SC-M1 to resist LAK cytotoxicity by means of a cytostatic effect through a mechanism relating to cell cycle regulation. The prevailing ideas, such as a decrease in effector to target cell binding, a reduced MHC class I antigen expression or an altered RARbeta expression, are not involved.

Biaxial flexural strength and indentation fracture toughness of three new dental core ceramics

The traditional gold and porcelain fused to metal crowns have been challenged by the esthetic all-ceramic crown materials. Only previous experience with poor mechanical properties, lack of standardized tooth preparation, and processing challenges have prevented universal acceptance of all-ceramic crowns. However, stronger and tougher ceramics and unique processing methods for ceramics have been developed in the past 20 years. In this study, three new ceramic crown core materials were tested to compare their biaxial flexural strength and indentation fracture toughness. Ten specimens of Empress, In-Ceram, and Procera AllCeram ceramics were prepared according to their manufacturers' recommendations. The results revealed significant differences in flexural strength for the three materials (p < or = 0.05). The average flexural strengths of AllCeram, In Ceram, and Empress ceramics were 687 MPa, 352 MPa, and 134 MPa respectively. There was no statistically significant difference between the fracture toughness of Procera (4.48 MPa x m1/2) and In-Ceram ceramics (4.49 MPa x m1/2); however, both ceramics had significantly higher fracture toughness (p < 0.005) than Empress ceramic (1.74 MPa x m1/2).

Localization of seminal plasma transforming growth factor-beta1 on human spermatozoa: an immunocytochemical study

OBJECTIVE

To localize immunocytochemically transforming growth factor beta1 (TGF-beta1) in human spermatozoa.

DESIGN

Incubation of spermatozoa with anti-TGF-beta1 antiserum at various pH.

SETTING

Human volunteers in an academic research institute.

PATIENTS

Young healthy fertile men.

INTERVENTIONS

Semen specimens were collected.

RESULTS

At neutral pH and at physiological pH of seminal plasma, TGF-beta1 immunostaining was detected predominantly at the postacrosomal region of the head, at the neck, and at the middle piece of the tail. Transforming growth factor-beta1 also was found occasionally at the axial filament complex of the connecting piece and the ring. The acrosomal cap section of the head, the principal piece, or the end piece of the tail were immunocytochemically negative for TGF-beta1. The TGF-beta1 immunostaining pattern at acidic pH was similar to that at neutral pH and at physiological pH of seminal plasma, but a greater intensity of immunostaining was found at acidic pH than that at neutral pH.

CONCLUSION

These results suggest that an in vivo activation of seminal plasma latent TGF-beta1 may take place in the acidic environment of vagina, which results in a greater amount of activated TGF-beta1 and, in turn, with an enhanced "coating" of TGF-beta1 to spermatozoa.

Stress distribution in the ankle-foot orthosis used to correct pathological gait

Abnormal motion of the ankle-foot complex presents a major problem in the rehabilitation of stroke patients. These patients often develop drop foot, a problem involving excessive and uncontrolled plantar flexion. An ankle-foot orthosis (AFO) is prescribed to constrain and inhibit this abnormal motion. The purpose of this investigation was to simulate the drop foot problem to determine the stress distribution in the orthosis. A quasi-static 3-D finite element analysis of the AFO complex was conducted using ADINA. Results confirmed the hypotheses that the maximum peak stress occurs in the neck, heel, and side-arc region of the AFO. However, the neck region of the AFO experienced the largest amount of stress. High stress concentration in the neck region observed in the present analysis is consistent with the common clinical observation that AFOs break down in the neck region.

Three-dimensional finite element stress analysis of the polypropylene, ankle-foot orthosis: static analysis

An asymmetric 3-dimensional finite element model (FEM) of the ankle-foot orthosis (AFO) together with the ankle-foot complex was developed using the computer aided design (CAD) program PATRAN. Static analysis of normal and pathological motions of the ankle-foot complex such as the "drop-foot" problem were conducted using the FEM program ADINA. A total of 313 three dimensional solid elements and 10 truss elements were used. Heel strike and toe-off condition were simulated. Results revealed that the peak compressive stress (1.6 MPa) in the AFO model occurred in the heel regions of the AFO and the maximum tensile stress (0.8 MPa) occurred in the neck region of the AFO during toe-off. Parametric analyses revealed that the model was sensitive to the elastic moduli of the AFO and of the soft tissue, but was relatively insensitive to the ligament stiffness. The results confirmed the hypothesis that peak stresses in the orthosis occur in the heal and neck regions of the orthosis.

Characterization of latent transforming growth factor-beta from human seminal plasma

PROBLEM

Human seminal plasma is known to exhibit immunosuppressive activity. Transforming growth factor beta (TGF-beta) has been identified as an immunosuppressive factor in human seminal plasma. Biologically active TGF-beta represents a family of 25-kDa homodimeric proteins linked with disulfide bonds. TGF-beta associates with high molecular weight proteins noncovalently to form a type of latency that is biologically inactive. Quantitative distribution of active form of TGF-beta versus inactive latent form of of TGF-beta, and mechanism of the TGF-beta activation in human seminal plasma remain to be elucidated.

PURPOSE

To characterize seminal plasma latent form of TGF-beta, including its concentration, and the mechanism underlying the activation of TGF-beta.

METHOD

Gel filtrations on ACA-34 and Biogel P-60 were used to fractionate seminal plasma. TGF-beta was measured by enzyme immunoassay using antibodies specific for TGF-beta 1 and TGF-beta 2, respectively. Radioreceptor assay with recombinant human [125I]-TGF-beta 1 was applied to qualitatively identify TGF-beta 1. Kinetic experiments with various pH, temperature and time, along with protease inhibitors, were performed to delineate the activation mechanism of latent TGF-beta 1.

RESULTS

Human seminal plasma contained both TGF-beta 1 and TGF-beta 2, predominantly in latent form. The total concentration of TGF-beta 1 averaged 238 ng/ml versus an average of 18 ng/ml for TGF-beta 2. The in vitro activation or release of TGF-beta 1 from latent TGF-beta 1 was achieved only at acidic pH of < 4.0, and was time and temperature dependent. At pH 3.7 and 37 degrees C, a significant activation of latent TGF-beta 1 was achieved after an incubation of only 15 min, reached the maximum at 120 min, and the activated TGF-beta 1 remained relatively stable for at least 24 h. The activation was not inhibitable by a series of protease inhibitors examined, alone or in combination (e.g., phenyl-methylsulfonyl fluoride, E-64, pepstatin, leupeptin, ethylenediamine tetraacetic acid). Competitive radioreceptor assay established the functional identity of TGF-beta 1 in human seminal plasma with recombinant human TGF-beta 1.

CONCLUSION

Human seminal plasma TGF-beta is biologically activated from high molecular weight latent TGF-beta by acid pH. The acidic environment of female lower genital tract could represent an in vivo physiological condition for activation of seminal plasma TGF-beta that may immunologically protect the integrity of sperm.

Effects of indomethacin on lymphokine-activated killer cell activities in cancer patients

Prostaglandin E2 (PGE2) is known to downregulate the generation of lymphokine-activated killer (LAK) cell activity. Indomethacin, an inhibitor of cyclooxygenase catalyzing the biosynthesis of PGE2, has been shown to augment LAK cell activities generated from peripheral blood mononuclear cells of normal healthy individuals. This study was undertaken to examine whether or not this augmentation is also a common phenomenon in cancer patients. LAK cell activities generated in the presence and the absence of indomethacin were examined in 15 normal healthy individuals and in 83 cancer patients. Paired data analysis revealed that indomethacin exhibited a significant augmentation of LAK activity generated from healthy individuals. Indomethacin enhanced LAK activity in patients with no distant metastases (TxNxM0); but depressed LAK activity in patients with distant metastases (TxNxM1). In patients without distant metastases, indomethacin showed an upregulating effect on LAK activity in those with an early T stage (T1-2NxM0), and no such effect was detected in those with a late T stage (T3-4NxM0). Indomethacin also significantly enhanced LAK cell generation in cancer patients with an ECOG performance status of 1, but significantly inhibited LAK cell generation in patients with a performance status of 4. These results indicated that indomethacin inhibited generation of LAK cell activity in cancer patients with a poor performance status or with distant metastatic disease, who normally would be the subjects of adoptive immunotherapy. Further, PGE2 production in cultured LAK cell medium was suppressed by indomethacin in all 20 cancer patients that were examined, suggesting that other yet to be identified factors or mechanisms may be responsible for the paradoxical effects of indomethacin on LAK cell activity.

Detection of soluble P-glycoprotein in culture media and extracellular fluids

Multidrug resistance (MDR) is a unique phenomenon in cancer patients and is commonly associated with an overexpression of the human MDR gene mdr1, which encodes an energy-dependent Mr 180 kDa membrane bound protein, known as P-glycoprotein. P-glycoprotein serves as a membrane efflux to pump the drugs out of the cancer cells. Western blot analysis, using a newly generated monoclonal antibody F4 which recognizes specifically an extracellular epitope of human MDR1 P-glycoprotein, reveals that soluble P-glycoprotein is detected in the cultured media of viable adriamycin-resistant human ovarian carcinoma 2780AD cells, whereas those of the drug-sensitive parent A2780 cells contain no detectable level of soluble P-glycoprotein. Soluble P-glycoprotein also is detected in extracellular fluids of cancer patients, such as malignant ascites and serum, and is not detectable in serum samples of normal healthy individuals. The Mr of soluble P-glycoprotein is the same as that of membrane bound P-glycoprotein. The presence of soluble P-glycoprotein in extracellular fluids may provide the basis for its use as a quantitative parameter of MDR and as a means to lessen or reverse MDR.

Prostate-specific antigen in screening of prostate cancer

Prostate-specific antigen (PSA) is a well-characterized human prostate-specific glycoprotein. PSA has been shown to be the most effective immunohistologic marker for prostate cancer, as well as the most useful serologic test in staging and monitoring prostate cancer and in early detection of recurrent disease. The greatest clinical value of PSA is an aid for early detection of prostate cancer. Recent studies have indicated that PSA-based screening of the older population for organ-confined early-stage prostate cancer is an acceptable, practical, and reliable modality. The accuracy of PSA screening is within the same range as the mammogram. The cost-effectiveness of PSA is comparable to other cancer screening tests. Although the increase in the patient's survival due to PSA-based detection of early prostate cancer remains to be documented, it is generally agreed that the PSA test along with digital rectal examination (DRE) should be included in the annual physical examination for men 50 years of age or older. High-risk men are urged to commence at age 40. Asymptomatic men who have both a negative DRE and normal PSA blood test need only to continue an annual DRE and PSA check-up. Men who have a negative DRE and elevated PSA, and all those who have a suspicious DRE regardless of PSA results, should undergo further diagnostic workup, such as transrectal ultrasonography with biopsy of visible lesions. The cure rate is high with timely treatment, when prostate cancer is detected while still confined to the prostate.

The augmentation of lymphokine-activated killer cell activity by indomethacin in vitro is not mediated by prostaglandin E2 suppression

The effects of three nonsteroidal antiinflammatory drugs (NSAIDs), namely, indomethacin, aspirin, and mefenamate (ponstan), on the lymphokine-activated killer (LAK) cell activities generated from coculturing recombinant interleukin-2 (rIL-2) and normal human peripheral blood mononuclear cells (PBMCs) for 3 to 4 days were investigated. The LAK cell activities were measured by a 4 hour 51Cr release microcytotoxicity assay using HL-60 and K-562 as target cells. Indomethacin was found to have significant augmenting effect on LAK cell activity at the concentration of 5 x 10(-5) M, whereas aspirin and ponstan did not show the same effect at the same concentration. Additional experiments, however, demonstrated that all of these 3 agents could effectively suppress the production of prostaglandin E2 (PGE2) in the culture medium. These results indicated that PGE2 suppression may not be the only mechanism of indomethacin for upregulation of LAK cell activity, and even immune functions.

Transforming growth factor beta as an immunosuppressive protein in human seminal plasma

PROBLEM

Human seminal plasma is known to exhibit immunosuppressive activity in seminal plasma.

PURPOSE

The purpose was to characterize immunosuppressive proteins in seminal plasma.

METHOD

Gel filtration fractions of 100 to > 440 kDa were identified that inhibited DNA synthesis and killing activity of interleukin-2 stimulated lymphocytes.

RESULTS

The fractions exhibiting immunosuppression also inhibited DNA synthesis in a mink lung cell bioassay commonly used to measure the activity for transforming growth factor beta (TGF-beta). The negative growth activity was diminished by a TGF-beta neutralizing monoclonal antibody. TGF-beta was further detected in the active fractions by Western immunoblot.

CONCLUSIONS

These results identified TGF-beta as an immunosuppressive protein in human seminal plasma and may provide insight into the role of immunosuppression played by seminal plasma, such as in reproduction and neoplasia.

Characterization of a new monoclonal antibody F4 detecting cell surface epitope and P-glycoprotein in drug-resistant human tumor cell lines

Using viable adriamycin resistant human ovarian carcinoma cells 2780AD and colchicine resistant human oral epidermoid carcinoma cells KB-24 as the immunogen in primary and subsequent i.p. immunizations, followed by i.v. boostings with crude plasma membranes of 2780AD, KB-24, Chinese hamster lung cells resistant to vincristine DC-3F/VCRd-5L, and resistant to daunorubicin DC-3F/DMXX, we have generated a new murine monoclonal antibody (McAb), designated F4, of IgG1 isotype. McAb F4 reacted strongly with a cell surface epitope of drug resistant cells and insignificantly with their drug sensitive counterparts. Cell surface localization of F4 epitope was determined by immunofluorescence and laser scanning confocal imaging system. Results obtained from immunoprecipitation and immunoblot analyses using F4 and mdr1 P-glycoprotein specific McAb JSB-1 demonstrated the reactivity of P-glycoprotein with F4. These results along with those obtained from competitive binding-inhibition, chemical modification, and enzyme hydrolysis, revealed that McAb F4 detects an extracellular epitope of P-glycoprotein, and is different from other major McAbs directed against P-glycoprotein, e.g. C219, MRK16, JSB-1, HYB-241 and C494. Deduced from the putative structure of mdr1 protein and its orientation in cell membrane, it is proposed that F4 epitope is localized in or near the 3rd, and/or 6th extracellular transmembrane loops of P-glycoprotein.

Enhancement of perforin by retinoic acid is mediated by protein kinase C

We previously demonstrated that interleukin-2 induced murine lymphokine-activated killer cell activity is augmented by retinoic acid. The enhanced cytotoxicity is significantly correlated with the increase in PKC. In the present study, we have shown that retinoic acid increases the expression of perforin, a potent cytolytic mediator, at both protein and mRNA levels. This enhancement can be induced by a direct stimulation of PKC signaling pathway, as manipulated by a short term incubation of lymphokine-activated killer cells with 12-O-tetradecanoyl-phorbol-13-acetate and ionomycin, and suppressed by PKC inhibitors. These results suggest that PKC plays a regulatory role in the enhancement of the expression of cytolytic mediators in retinoic acid-augmented lymphokine-activated killer cells.

Responsiveness of murine lymphokine-activated killer activity to prostaglandin E2 at late phase of interleukin-2 induction

To elucidate the inhibitory effect of prostaglandin E2 (PGE2) on the generation of recombinant interleukin-2 (IL-2)-induced lymphokine-activated killer (LAK) activity, we have examined the association between cellular 3',5'-cyclic adenosine monophosphate (cAMP) and cytolytic activity of 3-day IL-2-cultured murine LAK cells, i.e. at late phase of IL-2 induction, in the presence and absence of PGE2. The results indicate that, at the late phase of IL-2 induction, LAK cells retain their responsiveness to PGE2 inhibition, and the inhibition can be partially suppressed by additional IL-2 in proportion to the decrease in the ratios of stimulated to basal cellular cAMP levels.

A lumped parameter mathematical model of the splanchnic circulation

A lumped parameter mathematical model to describe the propulsion of blood in the splanchnic circulation was developed by integrating the principles of mechanics and physiology. A set of governing equations by derived by specifically considering the contractility of the portal vein, hepatic vein, liver sinusoids, and of the draining lymphatics. These equations were then simulated on a computer. The present simulation results substantiate previous experimental observations that hepatic venous pressure leads to portal hypertension and increased liver interstitial fluid volume.

Enhanced cell-mediated cytotoxicity by interferon-gamma and interleukin-2 against syngeneic murine mammary adenocarcinoma

The effect of murine recombinant interferon-gamma (IFN-gamma) on cell-mediated cytotoxicity against tumor cells in vitro and in vivo was investigated using a spontaneously developed, weakly immunogenic, syngeneic murine mammary adenocarcinoma, designated JC, as the target. Preincubation of JC tumor cells with IFN-gamma increased the susceptibility of lysis by both cytotoxic T lymphocytes and interleukin-2 (IL-2)-induced lymphokine-activated killer cells in an IFN-gamma dose-dependent manner. A direct injection of IFN-gamma (10,0000 U/d) daily for 5 consecutive days into the JC tumor nodule on the backs of BALB/c mice reduced the tumor growth in comparison with that of the control group. This antitumor activity was further enhanced by combination with a simultaneous intraperitoneal injection of IL-2 (300,000 IU/d) daily for 5 consecutive days. Phenotypic examination of tumor-infiltrating lymphocytes after injection of IFN-gamma plus IL-1 revealed an increased percentage of the cells expressing asialo GM1, L3T4, and IL-2 receptors. Additionally, an enhanced expression of major histocompatibility complex class I molecules on the JC tumor cells was detected. These results indicated that a direct injection of IFN-gamma into the tumor accompanied with the administration of IL-2, by enhancing cell-mediated immunity of the hosts and expression of major histocompatibility complex class I antigens on target cells, will be of potential clinical value.

Enhancement of protein kinase C in murine lymphokine-activated killer cells by retinoic acid

We previously reported that retinoic acid (RA) augmented mouse (BALB/c) lymphokine (interleukin-2)-activated killer (LAK) cell activity in a dose and time dependent manner. As evidence available has suggested the role of protein kinase C (PKC) in the regulation of cell mediated cytotoxicity, the present work was to investigate whether or not PKC may mediate the enhancement of LAK cell activity by RA. Accompanied with an augmented LAK cell activity, RA increased total PKC enzyme activity, [3H]phorbol 12,13-dibutyrate binding activity, and the amount of immunoreactive PKC. A prolonged treatment (18 h) of LAK cells with 12-O-tetradecanoylphorbol-13-acetate resulted in the loss of both PKC and LAK cell activity. PKC inhibitors, 1-(5-isoquinolinesulfonyl)-2-methyl-piperazine dihydrochloride and staurosporine, also drastically reduced LAK cell activity. Although most of the total PKC activity (97%) was detected in the cytosol fraction, the increase in PKC activity was attributed to an increased enzyme activity in both cytosol and membrane fractions, and shown to be RA dose-dependent. Kinetics study revealed that the increase in PKC was a time-dependent process and the enhancement was detectable as early as 8 h after the addition of RA to LAK cell culture. By immunoblotting, the cytosol PKC of LAK cells was shown to contain alpha and beta isoforms, but not gamma. RA further increased the expression of PKC alpha. The enhanced expression of alpha isozyme of PKC by RA was also in a dose and time dependent manner. Taken together, these results indicate that the mechanism of the augmentation of LAK cell activity by RA may in part result from the increase in PKC, especially PKC alpha isozyme.

Effects of high-energy shock waves on murine renal cell carcinoma

The effects of high-energy shock waves (HESW) on a murine renal cell carcinoma (RenCa) was investigated. In vitro exposure of tumor cells to HESW resulted in a dose-dependent reduction in cell viability as determined by trypan blue dye exclusion, plating efficiency, growth curve, and soft agar clonogenic assays. Activity of lactic dehydrogenase (LDH) was detected in the supernatant after the HESW treatment due to cellular destruction, and a dose-dependent increase in cytocidal effect was demonstrated. Ultrastructural changes with swelling and distorted cristae of mitochondria, vacuolation, ribosomal lysis, and chromatinolysis were observed in HESW-treated RenCa cells. Flow cytometric (FCM) study revealed that DNA content of RenCa cells diminished after 200 HESW treatment, and RNA content of tumor cells decreased markedly after 400 HESW treatments. Partial or complete inhibition of tumor growth was shown in both animal modalities of subcutaneous inoculation and intravenous injection with sequential lung metastases. This study stressed again that HESW may play a role in combinational protocol for the treatment of human renal cell carcinoma in certain circumstances.

Differential hydration of dA.dT base pairing and dA and dT bulges in deoxyoligonucleotides

The role of water in the formation of stable duplexes of nucleic acids is being studied by determining the concurrent volume change, heats, and counterion uptake that accompany the duplexation process. The variability of the volume contraction that we have observed in the formation of a variety of homoduplexes suggests that sequence and conformation acutely affect the degree of hydration. We have used a combination of densimetric and calorimetric techniques to measure the change in volume and enthalpy resulting from the mixing of two complementary strands to form (a) fully paired duplexes with 10 or 11 base pairs and (b) bulged decameric duplexes with an extra dA or dT unmatched residue. We also monitored absorbance vs temperature profiles as a function of strand and salt concentration for all four duplexes. Relative to the decamer duplex, insertion of an extra dA.dT base pair to form an undecamer duplex results in a favorable enthalpy of -5.6 kcal/mol that is nearly compensated by an unfavorable entropy term of -5.1 kcal/mol. This enthalpy difference correlates with a differential uptake of water molecules, corresponding to an additional hydration of 16 mol of water molecules/mol of base pair. Relative to the fully paired duplexes, both bulged duplexes are 12-16 degrees C less stable and exhibit marginally larger counterion uptake on forming the duplex. The enthalpy change is slightly lower for the T-bulge duplex and less still for the A-bulge duplex. The volume change results indicate that an unmatched residue increases the amount of coulombic and/or structural hydration. The combined results strongly suggest that the destabilizing forces in bulged duplexes are partially compensated by an increase in hydration levels.

Homodimer and heterodimer subunits of human prostate acid phosphatase

Human prostatic acid phosphatase (PAP) isoenzymes, designated PAP-A and PAP-B, were isolated from human seminal plasma by sequential affinity chromatography on concanavalin A and L(+)-tartrate, a classic inhibitor of PAP. Both the major PAP-A and the minor PAP-B isoenzymes exhibited a similar molecular mass (100 and 105 kDa respectively), multiple pI values (5.05-5.35 and 5.05-5.12), and substrate and inhibitor specificity. Immunological characterization revealed that PAP-B possesses distinct antigenic determinants, in addition to the common sites shared with PAP-A. SDS/PAGE indicated that both isoenzymes are composed of two subunits of 50 kDa each. At high salt concentration, PAP-B dissociated completely into single subunits of 50 kDa, whereas PAP-A remained intact at 100 kDa. PAP-B was resolved by reverse-phase h.p.l.c. into three components, designated alpha, beta and gamma, each of 50 kDa, at a molar ratio of approx. 2:1:1. PAP-A contained a single component of molecular mass 50 kDa. The single component of PAP-A and the alpha component of PAP-B possessed identical amino acid compositions and N-terminal sequences, which were different from those of the beta and gamma components. These results indicate that human PAP contains three isoforms, alpha 2, alpha beta and alpha gamma. PAP-A, the major isoenzyme, is a homodimer consisting of two identical subunits (alpha 2), and PAP-B, the minor isoenzyme, is a mixture of two heterodimers, consisting of non-identical subunits (alpha beta and alpha gamma).

Endogenous protein substrates for prostatic acid phosphatase in human prostate

In order to identify the endogenous phosphoprotein substrates for human prostatic acid phosphatase (PAP), cellular proteins of human normal, benign, and malignant prostatic tissues as well as carcinoma cell lines were phosphorylated by the cellular kinases in the presence of (gamma-32P)-ATP and then were subjected to dephosphorylation reaction by PAP. Of several endogenous phosphoproteins, PAP preferentially dephosphorylated a cytosolic protein of Mr 83 kDa. The dephosphorylation of the 83 kDa phosphoprotein (designated pp83) by PAP was uniformly observed in all cells/tissues of prostate origin, and was completely inhibited by L(+)-tartrate, the classic inhibitor of PAP. Phosphoamino acid analysis revealed that pp83 was a tyrosine-poor phosphoprotein and was mostly dephosphorylated by PAP at serine/threonine residues rather than tyrosine residues. Further comparison of dephosphorylation rate with that of an endogenous phosphotyrosine-containing phosphoprotein (pp53) revealed that PAP possessed both phosphoserine/threonine protein phosphatase and phosphotyrosine protein phosphatase activity. These results demonstrate that pp83 apparently is an endogenous substrate of PAP in human prostate, and that, instead of a phosphotyrosine protein specific phosphatase, PAP is a universal protein phosphatase hydrolyzing equally well the phosphotyrosine, serine, and threonine residues.

Synergistic antitumor activity of interleukin-2 and cimetidine against syngeneic murine tumor

Cimetidine, an H2 histamine receptor antagonist, is a potent immunomodulating agent, which acts by inhibiting suppressor T lymphocyte function. The present work investigated the effect, if any, of cimetidine on interleukin-2 (IL-2)-induced natural killer (NK) and lymphokine-activated killer (LAK) cell activities, and on in vivo antitumor activity using syngeneic colon 26 adenocarcinoma as the model. Mimicking the clinical conditions, all in vitro experiments were evaluated with the splenocytes prepared from tumor-bearing BALB/c mice. Ten days after subcutaneous inoculation of tumor cells (5 x 10(5)), animals were treated intraperitoneally daily with phosphate-buffered saline (PBS), cimetidine (2 mg kg-1 day-1), IL-2 (300,000 IU/day), or cimetidine plus IL-2 for 7 consecutive days. The treatment of IL-2 plus cimetidine increased NK and LAK cell activities significantly and synergistically at the end of the treatment (i.e. on day 18) as well as 1 week after the treatment (i.e. on day 25), in comparison with those of the control groups (PBS, cimetidine alone, IL-2 alone). Also, in vivo antitumor activity, as analyzed by a Kaplan-Meier life table with the log-rank test, revealed a significantly prolonged survival in the group treated with IL-2 plus cimetidine compared to the control groups. Phenotyping performed on the murine splenocytes on day 18 indicated a significant reduction in Lyt2-positive cells in the cimetidine-treated group in comparison with the PBS group. A significant increase in asialo GM1-positive cells and IL-2-receptor-positive cells was detected in the group treated with IL-2 plus cimetidine in comparison with the PBS and IL-2 control groups. Therefore, this study indicates a synergistic enhancement of IL-2-induced NK and LAK cell activities in tumor-bearing hosts by cimetidine, a noncytotoxic inhibitor of suppressor T function, and a significantly prolonged survival of tumor-bearing animals treated by IL-2 plus cimetidine. It also suggests the clinical potential of combination therapy of IL-2 with cimetidine.

Prostaglandin E2 from macrophages of murine splenocyte cultures inhibits the generation of lymphokine-activated killer cell activity

The present work investigated the association between prostaglandin E2 (PGE2) from macrophages and its inhibition of murine lymphokine-activated killer (LAK) cell generation. The coculture of indomethacin with interleukin-2 (IL-2) augmented LAK cell activity in an indomethacin dose-response manner, and diminished PGE2 content in the corresponding culture supernatant in a reverse dose-response manner. The correlation between the increase in LAK cell activity and the decrease in PGE2 content was highly significant. Identical results were obtained with diclofenac. A profound inhibition of LAK cell activity by exogenous PGE2 in a dose-response manner was detected. Polyclonal anti-PGE2 antiserum augmented in a dose-dependent manner the LAK cell activity, by neutralizing PGE2 in the medium. A reduction of PGE2 content in the culture supernatant was also detected when the macrophage subpopulations were cultured and was indomethacin dose-dependent. In comparison with that of normal mouse splenocytes, the incubation of whole splenocytes of tumor-bearing mice, which contained a greater subpopulation of macrophages (24% vs. 12%), produced a greater PGE2 content and a correspondingly depressed LAK cell activity. Additionally, PGE2 reduced protein kinase C (PKC) activity along with LAK cell activity generated from macrophage-depleted T cells and natural-killer-like cells. These results overall indicate that PGE2 from macrophages in murine splenocyte cultures inhibits the LAK cell generation, and PKC may be involved in the inhibition mechanism.

The in vivo distribution of murine lymphokine activated killer cells in splenectomized host

The in vivo distribution of intravenously injected lymphokine activated killer (LAK) cells, generated in vitro with rIL-2 from normal murine splenocytes, was studied in BALB/c mice and compared with that of normal splenocytes. Both normal splenocytes and LAK cells were labeled with 51Cr, and the results were analyzed at 6, 24, and 48 hours after injection by localization index as the parameter. After injection through tail veins of mice, LAK cells were found to migrate to the spleen, lungs, liver, lymph nodes, bones and the kidneys. The apparent increased distribution pattern of LAK cells to the lung at 6 and 24 hours after injection was not detected when normal splenocytes were injected. Since almost one third of the injected LAK cells were found to localize in the spleen, it was postulated that splenectomy would affect the in vivo organ distribution of LAK cells. Accordingly, the in vivo distribution of LAK cells in splenectomized mice was further investigated. Results indicated that splenectomy enhanced the convergence of LAK cells to the lungs, liver, lymph nodes and bones. Therefore, splenectomy may augment the therapeutic effect of the adoptive transfer of LAK cells in pulmonary, hepatic, lymph node and bony metastases.

Prostaglandin E2-mediated suppression of murine lymphokine-activated killer cell activity generated from tumor-bearing hosts by interferon-gamma

The effect of mouse recombinant interferon-gamma (IFN-gamma) on murine lymphokine-activated killer (LAK) cell activity was investigated using a natural killer-resistant, LAK-sensitive, spontaneously developed, weakly immunogenic, syngeneic murine mammary adenocarcinoma, a tumor model mimicking that of human disease. When all of the splenocytes prepared from tumor-bearing mice were cultured with recombinant interleukin-2 (IL-2) and IFN-gamma, LAK cell activity was suppressed in an IFN-gamma dose-dependent manner. An increase in the prostaglandin E2 (PGE2) content in the corresponding culture media was detected, as was IFN-gamma dose dependent. The suppression of generation of LAK cell activity by IFN-gamma was abrogated, accompanied by the elimination of the increase in PGE2 content, when plastic dish and nylon wool-treated nonadherent macrophage-depleted splenocytes were used. These results indicated that IL-2-induced LAK cell activity generated from the splenocytes of tumor-bearing mice was suppressed by IFN-gamma, and that PGE2 secreted from the macrophages of the splenocyte cultures served as the mediator in this IFN-gamma dose-dependent suppression of IL-2-induced LAK cell activity.

Enhancement of murine lymphokine-activated killer cell activity by retinoic acid

Since retinoids have been suggested to be capable of potentiating immunity, the present study was undertaken to determine the effect, if any, on lymphokine-activated killer (LAK) cell activity by retinoic acid, an active metabolite of vitamin A and a differentiation enhancer. Retinoic acid alone was shown to induce no cytotoxicity generated from nylon wool-treated nonadherent murine (BALB/c) splenocytes against natural killer-resistant, LAK-sensitive syngeneic target tumor cells. When combined with human recombinant interleukin-2 (IL-2), retinoic acid augmented LAK cell activity in both a dose- and time-dependent manner. The augmentation was detected at 10(-10) M retinoic acid and reached the maximum at 10(-7) M, a greater than 200% increase in lytic activity. Kinetic study revealed that retinoic acid augmented significantly LAK cell activity when incubated in IL-2-containing culture as short as for 6 h before cytotoxicity was measured. The removal of retinoic acid from culture resulted in the loss of the augmentation. Retinoic acid was found to augment LAK cell activity in a wide range of IL-2 concentrations (750-12,000 IU/ml), even at 6,000 IU/ml where the maximal induction of LAK cell activity had been reached. No phenotype or proliferation of LAK cells was altered by the addition of retinoic acid to IL-2-containing culture. However, cellular serine protease activity, measured as N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl-esterase, in LAK cells was increased by retinoic acid also in a dose- and time-dependent manner. The increase in LAK cellular serine protease activity was significantly correlated with that of augmented LAK cell activity. Overall these results demonstrated that IL-2-induced LAK cell activity was enhanced by retinoic acid and that the augmentation may be mediated by means of enhanced expression of cellular serine protease activity. This study also suggests that, in addition to its use in chemoprevention of cancer, retinoic acid is of potential in adoptive immunotherapy.

Indirect inhibition of generation of murine lymphokine-activated killer cell activity in splenocyte cultures by interferon-gamma

The effect of mouse recombinant interferon-gamma (rIFN-gamma) on murine lymphokine-activated killer (LAK) cell activity was investigated using natural killer (NK)-resistant, spontaneously developed, weakly immunogenic and highly tumourigenic, syngeneic murine mammary adenocarcinoma, JC, mimicking that of human disease, as the target. Murine YAC-1 also was used as a target cell line. rIFN-gamma, when used in combination with recombinant interleukin-2 (rIL-2), was shown to exhibit a suppressed effect on LAK cell activity generated from BALB/c mouse splenocytes, compared to that with rIL-2 alone. The decrease in LAK cell activity was rIFN-gamma dose-dependent. Kinetic study revealed that this inhibitory effect was demonstrated only when rIFN-gamma was added to the medium at the early phase of rIL-2 culture. The inhibitory effect on LAK cell generation by rIFN-gamma was completely abrogated when the nylon-wool-treated non-adherent 'macrophage-free' splenocytes were incubated with rIL-2 and rIFN-gamma. These results indicated that the LAK cell activity generated from murine splenocytes cultured with rIL-2 could be depressed by rIFN-gamma, and that the macrophages may be involved as mediators.

Prolongation of serum half-life of interleukin 2 and augmentation of lymphokine-activated killer cell activity by pepstatin in mice

We reported previously using a murine model that the kidney is the organ involved in catabolism of exogenous human recombinant interleukin 2 (IL-2) and that cathepsin D, a major renal acid protease, is responsible for the degradation of IL-2. In the present report also using BALB/c mice we have investigated the effect of in vivo pepstatin, an acid protease inhibitor, treatment on serum half-life of IL-2, and generation of lymphokine-activated killer (LAK) cell activity. The in vivo pepstatin treatment by i.p. injection resulted in a significant reduction in the accumulation of 125I-IL-2 by the kidney in a reverse dose-response manner. Pepstatin treatment prolonged the serum half-life of 125I-IL-2, and the increase in serum half-life of 125I-IL-2 was pepstatin dose dependent. A significant reduction in renal cathepsin D activity, as monitored by the degradation of 125I-IL-2, was detected. In vivo pepstatin (0.6 mg/kg) treatment along with IL-2 (300,000 IU/mouse) daily for 3 or 6 days resulted in an augmentation of natural killer activity exhibited by freshly prepared and uncultured splenocytes against YAC-1 cells. An additional culturing of the splenocytes with IL-2 (3,000 IU/ml) in vitro for 1 day significantly enhanced the effect of in vivo pepstatin treatment; i.e., LAK cell activity generated from the splenocytes of animals treated with IL-2 plus pepstatin was greatly augmented in comparison with that treated with IL-2 alone. Phenotypic assessment by cell surface markers (Thy-1.2, Lyt-2, L3T4, and asialo-GM1) on the fresh splenocytes prepared from animals treated in vivo with pepstatin plus IL-2 revealed a decrease in the percentage of cells expressing Thy-1.2 and Lyt-2 and an increase in those carrying asialo-GM1. These results demonstrated that, as a result of in vivo pepstatin treatment, renal cathepsin D activity was greatly inhibited, which in turn reduced the degradation of circulating IL-2, then prolonged serum half-life of IL-2, and subsequently augmented natural killer and LAK cell activity. The in vivo pepstatin and IL-2 treatment decreased the T-cells and increased the natural killer-like LAK precursor cells, possibly also with an increase in its activity, which were further induced by in vitro IL-2 culture to generate an augmented LAK cell activity. This study also suggests the clinical potential of pepstatin in IL-2-related immunotherapy.

Prostate-specific antigen: questions often asked

In conclusion, an effective new marker for prostatic tissue has been identified and is commonly known as PSA. A review of the literature indicates that although PSA is not tumor specific, its organ-site and cell-type specificity provide the basis for making PSA the marker of choice for use in patients with prostate cancer. The clinical utility of PSA includes monitoring therapeutic efficacy, screening and early diagnosis in high-risk patients, prognosis, staging, and tumor volume evaluation, prediction of disease progression, detection of recurrent disease after radical prostatectomy, and the differential diagnosis and confirmation of tissue for prostatic origin. PSA is not a "magic bullet" for patients with prostate cancer. Many questions must still be answered. For example, with an increase in sensitivity for screening of high-risk populations, how does the urologist/oncologist determine which patients with latent curable early cancer will develop into clinically significant metastasis? Is PSA a more reliable method for detection of early prostate cancer than rectal examination? What procedure should be followed for an asymptomatic patient who presents a 35 ng/ml level of PSA during a routine physical examination? Clearly, further studies are required to answer these questions as well as to assess the malignant potential of the prostatic tumor cell. For now, the combination of PSA, rectal examination, and transrectal ultrasonography guided needle biopsy would appear to be the method of choice to decrease the yearly fatalities due to cancer of the prostate.

Comparison of prostate acid phosphatase with acid phosphatase isoenzymes from the lung and spleen

Acid phosphatase was purified to electrophoretic homogeneity from human normal lung and spleen and was characterized biochemically and immunologically in comparison with prostate acid phosphatase (PAP). The apparent MW of lung acid phosphatase (LAP) and spleen acid phosphatase (SAP) was 110,000 and 100,000, respectively, similar to that of PAP (100,000). All three enzymes exhibited similar electrophoretic mobility, optimal pH, substrate, and inhibitor specificity, except that PAP dephosphorylated profoundly the phosphate group from tyrosine phosphate in phosphoangiotensin (19,700 fmol/mg/min), whereas only marginal activities were detected for LAP and SAP (19 and 73 fmol/mg/min, respectively). Amino acid analysis revealed more similarity between SAP and LAP than PAP and LAP or PAP and SAP. An immunological cross-reactivity among these three acid phosphatases was detected by polyclonal and monoclonal antibodies raised against purified PAP, although unique epitopes were detected on the PAP molecule. This study provides data explaining why conventional biochemical methods are not specific for PAP measurement and why immunologic methods still detect other acid phosphatases, as observed in clinical laboratory assays. The data also suggest the possibility of using a new substrate or antibody reagent for a more specific assay for PAP.

Characterization of a new spontaneously developed murine mammary adenocarcinoma in syngeneic BALB/c hosts

A mouse mammary tumor cell line, designated JC, has been established from a spontaneously developed primary adenocarcinoma of an aged virgin female BALB/c mouse. Isoenzyme analyses including glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and peptidase proved that this cell line is of murine origin and devoid of contamination from other species. Karyotyping revealed that the number of chromosome ranged from 26 to 100, with a modal number of 40. Electron microscopic examination detected the presence of tonofilament and desmosomes confirming its epithelial nature. In addition, no type B or C virus particle was detected, although intracysternal A particle was observed occasionally. Tumorigenicity in immunocompetent syngeneic hosts was easily established by s.c., i.p., and i.v. injection of viable JC tumor cells. A very weak immunogenicity of the JC tumor was demonstrated through its immunization-challenging on syngeneic immunocompetent hosts. Although no rejection of JC tumor was noted, a significant prolongation for the incubation period before an obvious and palpable tumor growth was detected between the experimental and the control animals. Development of a concomitant immunity was also detected. The JC tumor represents a valuable murine mammary tumor model which is different from other available models because of its unique origin, absence of virus particles, very weak immunogenicity, and high tumorigenicity in syngeneic hosts. The cell line has been maintained for more than 5 yr and has been used for experimental immunotherapy in our laboratory.

Serum level of cryptic tumor antigens in breast cancer patients as determined by two monoclonal antibodies (M85/F36) and its comparison with CA 15-3

An enzyme immunoassay system that measures cryptic epitopes on breast cancer mucinlike antigens (BCM-EIA) was evaluated in a double-blind manner in sera from 58 normal blood donors, 36 sex- and age-matched controls, 36 patients with benign breast diseases, and 47 patients with breast cancer. Two murine monoclonal antibodies, M85 (IgM) as the solid-phase and F36/22 (IgG3) as the probe, were used in the configuration of the assay kit. The assay additionally utilized neuraminidase to remove terminal sialic acid from carbohydrate side-chains to expose cryptic epitopes that were masked in serum specimens. BCM-EIA monoclonal assay from the normal healthy blood donors resulted in 17.34 +/- 7.04 units/ml (mean +/- 1 S.D.) with an upper normal cutoff of 31.4 units/ml. The distributions of serum BCM in the sex- and age-matched controls (17.77 +/- 11.17) and benign breast diseases (14.34 +/- 11.46) were similar to that of normal blood donors. A mean value of 66.04 units/ml and 27.74 units/ml was obtained from breast cancer patients with active disease and without evidence of disease, respectively, a level much greater than those of normals, controls, and benign breast diseases. Simultaneous analysis of CA 15-3, a putative breast tumor marker, in the normal donors and breast cancer patients revealed correlation regression of (CA 15-3) = 0.876 (BCM) + 1.972, r = 0.856; and (CA 15-3) = 0.66 (BCM) + 16.094, r = 0.730, respectively. These data showed that there is a statistically significant correlation of CA 15-3 and BCM in normal blood donors' specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of the kidney in metabolic change of interleukin-2

The metabolic change of human recombinant interleukin-2 (IL-2) was investigated by the use of 125I-labeled IL-2 (125I-IL-2). After intravenous injection into mice, the distribution of 125I-IL-2 in various organs revealed that the major portion of injected 125I-IL-2 was rapidly accumulated in the kidney. Simultaneous injection of an excess amount of cold IL-2 greatly reduced the distribution of 125I-IL-2 to the kidney, suggesting that the accumulation of 125I-IL-2 by the kidney was a specific reactivity between 125I-IL-2 and the kidney. The gel filtration profile of 125I-IL-2 in the serum specimens remained the same as that of the originally injected sample, and differed completely from that in the urine specimens, suggesting that 125I-IL-2 was metabolized in the kidney. To confirm this notion, 125I-IL-2 was incubated in vitro with kidney homogenate, which degraded 125I-IL-2 in acidic pH. After subcellular fractionation, the cytosol fraction of the kidney was shown to hydrolyze 125I-IL-2 with an optimal pH of 4. The reactivity of the kidney cytosol fraction with 125I-IL-2 was inhibitable by pepstatin, an acid protease inhibitor, but not by TLCK or TPCK. Additional experiments using a heat-treated kidney cytosol fraction plus cathepsin D, and pepstatin inhibition on the degradation of 125I-IL-2 by cathepsin D, a major acid protease in the kidney, resulted in the identification of this enzyme to be responsible for the degradation of 125I-IL-2. Overall, these results demonstrated that the kidney is the organ to metabolize IL-2 and that cathepsin D, a renal acid protease, is involved in the degradation of IL-2.

Prostate-specific antigenic domain of human prostate specific antigen identified with monoclonal antibodies

With the use of five murine monoclonal antibodies (1A5, 2A4, 3F1, F5 and 3A12) and an antigen-affinity purified goat polyclonal IgG antibody, the presence of a prostate-specific antigenic domain in human prostate-specific antigen molecule was identified. The results were based upon a series of quantitative competitive inhibition assays of each 125I-labeled monoclonal antibody and polyclonal antibody binding to prostate-specific antigen by unlabeled monoclonal antibodies as inhibitors, and immunohistochemical examination of an extensive panel of human tissue specimens. A cluster of two epitopes that are spatially related or in close topographical proximity and represent a prostate-specific antigenic domain are defined by the monoclonal antibodies 1A5, 2A4, 3F1, and F5, 3A12, respectively.