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Biomedical subjects

M A Kosir

Publications and source records attributed to M A Kosir.

12 recordsLinked to original sources
PubMed1999

Degradation of basement membrane by prostate tumor heparanase.

BACKGROUND: The degradation of basement membrane (BM) by cancer is an important event that characterizes invasive biological behavior. A component of BM is heparan sulfate proteoglycan (HSPG). The glycanase(s) that degrade HSPG in BM are not yet isolated. We recently identified HSPG-degrading activity (PC-3M heparanase) in the conditioned media (CM) of malignant prostate carcinoma cells (PC-3M and LNCaP C4-2). Antibodies (Abs) to a recently isolated heparanase from human platelets (CTAP-III), cross-react with PC-3M heparanase although they differ in size; under reduced conditions PC-3M heparanase is 60 kDa whereas CTAP-III is 10 kDa by polyacrylamide gel electrophoresis. PC-3M heparanase therefore shares homology with CTAP-III. The purpose of this study was to test the inhibition of PC-3M heparanase by Abs specific to the N- and C-terminals of CTAP-III. MATERIALS AND METHODS: CM from PC-3M and LNCaP C4-2 cells were tested for heparanase activity. Each reaction contained substrate as [3H]glucosamine-labeled HSPG (>50 kDa) from the BM of the EHS tumor, CM from PC-3M or LNCaP C4-2 cells, and inhibitor or buffer (negative control). Protease inhibitors were present throughout. After incubation for 3-20 h at 37 degreesC and pH 5.8, the reaction was stopped with 0.2% SDS. Each reaction mixture was centrifuged in an Ultrafree-MC 30,000 NMWL filter unit (Millipore) and radioactivity in the filtrate counted by scintillation counting. Results. For both cell lines, there was a linear relationship between the amount (microgram) of CM and degradation of HSPG. Degradation was inhibited by 54.1% (mean) using carrageenan lambda (10 microgram/ml), a nonspecific glycanase inhibitor (P < 0.05 by ANOVA). Ab to the N-terminus of CTAP-III (anti-Hep A) reduced degradation by 10-50% (mean 31.1%) and to the C-terminus (anti-Hep C) by 38.8-64.3% (mean 51.1%) (P < 0.003 by ANOVA). CONCLUSIONS: The degradation of HSPG by malignant prostate cancer cell lines is inhibited by both a nonspecific glycanase inhibitor, and specific Abs to a homologous platelet heparanase. Based upon molecular weight, PC-3M heparanase is different from platelet heparanase and degrades BM.

Amino Acid Sequence↗
PubMed1998

Prospective double-arm study of fibrinolysis in surgical patients.

BACKGROUND: During surgery, the balance between thrombosis and fibrinolysis is altered. Methods reported to increase fibrinolysis, such as compression devices, may reduce venous thrombosis. However, there are no prospective studies comparing methods and the effect on fibrinolysis. MATERIALS AND METHODS: In a prospective study, general surgical patients were randomized to either sequential compression devices (Group 1) or subcutaneous heparin (Group 2), and fibrinolysis factors were measured in order to determine the effect on the fibrinolysis system. Blood samples were drawn at a similar time of the day with the tourniquet off. Specifically, t-PA antigen, plasminogen activator inhibitor-1 (PAI-1), and D-dimer were measured preoperatively (preop) and on Postoperative Days (POD) 1 and 7 by the ELISA method. Fibrinolysis factors were reported as the mean +/- SD and as percentage change from preoperative values. Noninvasive vascular studies were performed preop, and on POD 1, 7, and 30, by an examination of the infrainguinal venous system and external iliac veins in bilateral lower extremities. Nonambulatory patients were excluded from the study and DVT prophylaxis methods were initiated at surgery and used through POD 2. RESULTS: For the 136 patients in the study, there were no differences in clinical characteristics such as age, surgical time (all > 60 min), anesthesia type (general or spinal), type of surgical procedure, or other risk factors for DVT. Two DVTs occurred at POD 1 and 30 (both Group 2), and one pulmonary embolism in each group (POD 7 for Group 1; POD 1 for Group 2). For subjects without thrombosis, D-dimer changes were parallel for both groups, increasing through POD 7. Similarly, t-PA antigen levels rose from baseline on POD 1 in both groups, with a return toward baseline by POD 7. The PAI-1 levels increased on POD 1 in both groups, but severalfold more in Group 1 (compression devices). The elevation in PAI-1 decreased by 50% in Group 1 by POD 7, while values returned to normal in Group 2. These changes were not significant using the Mann-Whitney test. Only three patients had thrombotic episodes so that data on changes in fibrinolysis factors are difficult to compare with the larger group. CONCLUSIONS: This is the first report of a prospective, randomized comparison of fibrinolysis factors using sequential compression devices in comparison to low dose unfractionated heparin in general surgical patients, and comparing postoperative values to preop. Both groups showed an enhanced fibrinolysis by elevation in t-PA antigen and D-dimer on POD 1, as expected when fibrinolysis occurs. While PAI-1 and t-PA work in parallel, the marked elevation of PAI-1 on POD 1 (although only slightly above reference values) and continuing into POD 7 for subjects using compression devices requires further inquiry. The elevation of PAI-1 in the face of elevated t-PA and D-dimer has been reported, but the comparison between patients using sequential compression devices and mini-dose heparin has not been reported. The reason for the elevation requires additional study into other influences on the synthesis, secretion, and/or function of PAI-1 that do not affect t-PA.

Female↗
PubMed1997

Human prostate carcinoma cells produce extracellular heparanase.

The degradation of heparan sulfate proteoglycan (HSPG) in basement membranes (BM) has been previously suggested to be accomplished by an endoglycosidase activity called heparanase which has not been isolated outside of platelets. HSPG degradation by heparanase has been associated with tumor cell invasion, angiogenesis, and growth factor function. In this study, we identify heparanase activity biochemically and immunologically in malignant human prostate carcinoma cells (PC-3M), linking platelet heparanase probes with the tumor heparanase activity observed. Concentrated conditioned medium from PC-3M cells was analyzed by a heparin-Sepharose affinity column. Three peaks eluted with 0.15, 0.35, and 0.5 M NaCl. Each peak was analyzed by incubation with 3H-labeled heparin as well as [3H]HSPG from EHS tumor BM. The 0.5 M peak material degraded [3H]-heparin by 17.2%, with little additional degradation by the other peaks in comparison to the conditioned medium from which they were obtained. Likewise, the same amount of the 0.5 M peak accounted for the majority of degradation (30.8%) of 3H-labeled HSPG. Interestingly, for the same amount of 0.5 M peak material, significantly more HSPG was degraded than heparin under the same conditions. In addition, carrageenan-lambda, an inhibitor of glycanase, completely inhibited the degradation of heparin and heparan sulfate proteoglycan by the 0.5 M peak. Using antibody to the N-terminus domain of platelet heparanase, a 60-kDa protein was identified by immunoblot in 0.5 M peak material. Additionally, immunohistochemical staining of human prostate carcinoma specimens showed granular staining at or near the cell membrane and near the luminal surface using antibody to the N-terminus and C-terminus domains of platelet heparanase. In summary, human prostate carcinoma cells show heparanase activity in conditioned medium that degrades heparin and BM HSPG and is detected by antibody to platelet heparanase. In addition, the membrane-associated staining in tissue sections of prostate cancer strongly correlates with the biochemical and immunological detection in conditioned medium of human PC-3M cells.

Chromatography, Affinity↗
PubMed1996

Is DVT prophylaxis overemphasized? A randomized prospective study.

This study was designed to prospectively evaluate a previously published prognostic index for predicting deep venous thrombosis (DVT) in general surgical patients with conventional prophylaxis. Patients undergoing procedures of at least 1 hr duration (abdominal, thoracic, head and neck, inguinal) requiring general or spinal anesthetic were prospectively randomized into the following groups: Group 1, sequential pneumatic compression devices during surgery and 2 days postoperatively; Group 2, subcutaneous heparin (5000 U q 12 hr) starting 1 hr before surgery and for 7 days postop; Group 3, control group. All patients underwent duplex evaluation of bilateral lower extremity deep venous systems preoperatively and on postoperative Days 1, 3, and 30. In addition, a previously developed predictive DVT incidence indicator, the prognostic index (PI), was calculated for each patient. A total of 137 patients were entered into the study with 29 removed for patient/staff reasons. There were no differences in PI among the three groups at the 0.05 level (ANOVA). The distribution of risk factors for DVT including increased age, body size, hemoglobin (Hb), and colorectal procedures were distributed evenly among the groups. Additional factors such as diabetes, COPD, PVD, immobilization, and cancer were also evenly distributed among the groups. The PI predicted a 20% incidence of DVT. For Groups 1 (n = 25), 2 (n = 38), and 3 (n = 45) no DVTs were detected over the 30 days of study. During the study period, 8 DVTs were detected by duplex evaluation in general surgical patients not in the study (1.5%). In conclusion, in a prospective randomized study using sequential pneumatic compression devices, subcutaneous heparin or no prophylaxis in matched general surgical patients at moderate to high risk for thromboembolism, no DVTs occurred for up to 30 days. Furthermore, neither a PI nor other factors associated with DVT accurately predicted the incidence of DVT in this patient population.

Adult↗
PubMed1995

Sorting of heparan sulfate proteoglycan into matrix compartments of prostate adenocarcinoma cells.

There is increasing evidence that the association of prostate carcinoma cells with the surrounding extracellular matrix is important for their growth. Proteoglycans (PGs) are components of matrix that form important associations with other molecules. Heparan sulfate proteoglycan (HSPG), for example, associates with several matrix components such as fibronectin, laminin, and basic fibroblast growth factor. The purpose of this study was to determine if human prostate carcinoma cells (PC-3) synthesized HSPG in tissue culture. Three areas of sulfate-labeled matrix were collected from PC-3 cells and analyzed: attachment sites, nonattachment cell surfaces, and media. Charged groups were separated by ion-exchange columns, and PGs identified by gel filtration chromatography after chemical and enzymatic treatment. The media fraction contained the greatest proportion of sulfated PGs (79.3%), of which 45.5% were HSPG. The greatest concentration of HSPG was in the attachment site fraction where 88.6% of PGs were HSPG, although only 11.7% of sulfated molecules were PGs. In nonattachment surfaces, only 19.6% were PGs, of which 19.4% were HSPG. When PGs were assessed for hydrophobic binding to octyl-Sepharose beads, only a proportion of HSPG in the media fraction contained hydrophobic domains (18.8%). In summary, PC-3 cells synthesize at least two types of HSPG, sorting them into different matrix compartments. The major PG in attachment sites is HSPG without a hydrophobic domain, while an HSPG in the media fraction has a hydrophobic domain. The localization of different types of HSPG may be functionally important and may be altered during the metastatic process for prostate carcinoma when in association with specific stroma.

Adenocarcinoma↗
PubMed1995

Splanchnic metabolism associated with liver metastasis.

Metastatic liver disease can modify the metabolic response to critical illness. Systemic lactic acidosis may arise from an increased production due to inadequate peripheral tissue oxygen transport, altered metabolic function such as depressed pyruvate oxidation or insufficient hepatic clearing capacity due to tumor replacement of functional liver mass. Hepatic venous catheterization in a patient with extensive metastatic melanoma to the liver and adult respiratory distress syndrome indicated a marked disparity between whole body and liver oxygenation which may arise due to a markedly stepped up splanchnic oxygen utilization unmatched by a proportionate rise in regional oxygen delivery. Since some neoplasms may exhibit increased metabolic activity, it is suspected that these metastatic lesions may have contributed to the observed regional hypermetabolism thereby worsening hepatic hypoxia and exacerbating lactic acidosis. This case also illustrates the difficulties in interpreting global indicators of metabolic function and oxygenation in critically ill patients.

Acidosis, Lactic↗
PubMed1991

Pediatric abdominal lymphangiomas: a plea for early recognition.

Abdominal lymphangiomas are usually classified together with mesenteric cysts. However, they differ by location, histology, and potential for recurrence, and should be considered a separate clinical entity. Thirteen children, aged 2 weeks to 11 years (mean, 5.8 years), with abdominal lymphangiomas were identified over the past 16 years at this institution. Of these, 12 were symptomatic. Abdominal pain (11), vomiting (8), increased abdominal girth (8), and nausea (6) predominated. Other presentations were less frequent. Symptoms were present for an average of 2 months (7 less than 1 week) before correct diagnosis. An abdominal mass was palpable in 10 cases. Intestinal gangrene secondary to volvulus was present in 2. Although multiple imaging modalities were used ultrasonography (8/8) and computed tomography (CT; 4/4) proved most expedient and reliable. In 2 cases, the lymphangioma could not be completely resected. There was 1 recurrence. Although intraabdominal cystic lesions are described in the literature as relatively symptom-free, our experience suggests otherwise. In this series, abdominal pain and an abdominal mass were common. Catastrophic complications can occur and excision is facilitated by earlier diagnosis and the benefit of smaller size. Ultrasound and CT can accurately diagnose the lesion and should be used liberally in children with intermittent or ill-defined abdominal pain, leading to prompt recognition and definitive treatment.

Abdominal Neoplasms↗
PubMed1990

Adhesion of Kirsten-ras+ tumor-progressing and Kirsten-ras- revertant 3T3 cells on fibronectin proteolytic fragments.

Adhesion has been evaluated for tumor cell populations derived from Kirsten murine sarcoma virus (KiMSV)-transformed BALB/c 3T3 cells responding to substrata coated with intact plasma fibronectin (pFN), a family of related proteolytic fragments from pFN or cellular fibronectins (FNs), and the heparan sulfate-binding platelet factor-4 (PF4). Both early-passage KiMSV cells, harboring the viral Kirsten ras oncogene (v-Ki-ras+), and late-passage KiMSV cells, in which most cells have lost the oncogene (v-Ki-ras-), are compared with primary tumor and lung metastatic tumor cells after three routes of injection into nude mice; nontumorigenic v-Ki-ras- revertant cells have been cloned from the late-passage KiMSV population. Attachment of early-passage KiMSV, primary tumor, and lung metastatic tumor cells was optimal and resistant to soluble RGDS peptide in the medium on intact pFN, on fragment F-155 from pFN containing the RGDS cell-binding domain and the heparinII domain, and on PF4 but decreased for metastatic cells on F110 containing only the RGDS domain (and sensitive to RGDS peptide). Cytoplasmic spreading of early-passage KiMSV and all tumor cells was good to excellent in polygonal patterns on pFN and on F155, while most cells remained round on F110. Responses for KiMSV and tumor cells varied on different heparin-binding proteins; cells remained rounded or detached on F38 derived from pFN or on PF4 but spread effectively with long linear process extension on cellular FN-derived fragments F44 + 47 harboring the extra domaina sequence. That F44 + 47 may contain a new cell-binding site for v-Ki-ras+ cells was also indicated by resistance to bacterial heparitanase in cell responses on F44 + 47 but not on PF4 and extensive catabolism of proteoglycans in the substratum-attached material of these cells. v-Ki-ras- revertant cells, nontumorigenic in nude mice, have reacquired 3T3-like responses to proteolytic fragments, including much more effective spreading on PF4 or on F38 substrata, and have reverted in generating microfilament stress fibers on pFN, a competence lacking in all v-Ki-ras+ cells. These results indicate that (a) v-Ki-ras+ primary and metastatic tumor cells respond similarly to most proteolytic fragments of FNs harboring known binding domains, with a few exceptions; (b) v-Ki-ras gene expression correlates with a new cell surface receptor activity recognized by extra domaina-containing fragments from cellular FNs; and (c) loss of the viral oncogene to generate v-Ki-ras- revertant cells reverts their FN-mediated adhesion responses.

Actins↗
PubMed1989

Heparan sulfate proteoglycans of Ras-transformed 3T3 or neuroblastoma cells. Differing functions in adhesion on fibronectin.

Initial studies described the significance of heparan sulfate proteoglycans of Balb/c 3T3 cells in their adhesion on fibronectin matrices, including their binding to multiple domains in FN, the importance of this binding in microfilament and close contact formation, and the cooperativity of both HS-PG and 140k glycoprotein integrin's binding to FN to achieve tight-focal contacts under cells. These analyses utilized model HS-binding proteins, such as platelet factor 4, and proteolytic fragments of FN with differing binding activities in both cell biological analyses of adhesion responses and in biochemical analyses of the HS-PG in the adhesion sites. In contrast, dermatan sulfate proteoglycans (DS-PG) inhibit 3T3 adhesion on FN but not on collagen; of special note is the discovery that certain integrin-binding fragments of FN also contain a third HS/DS-binding domain that is cryptic and that provides a more effective mechanism for inhibiting integrin: FN binding. Kirsten Ras oncogene-transformed 3T3 cells and their nude-mouse-derived primary or lung metastatic tumors are also being analyzed by similar approaches. HS-PGs in the adhesion sites of these tumor populations undergo extensive catabolism, resulting in alteration of their binding to FN affinity columns (and by implication alteration in adhesion responses of these tumor cells on FN matrices). Functions for HS-PG on the surface of neuronal cell derivatives, e.g., neuroblastoma cells derived from the neural crest of the embryo and potentially related in some ways to peripheral neurons, are also being explored. HS-binding fragments of FN or PF4 facilitate attachment and spreading of neuroblastoma cells but not neurite outgrowth, contrasting with the ability of dorsal root ganglion neurons to extend neurites on HS-binding substrata. The catabolism of HS-PG in neuroblastoma adhesion sites is minimal, indicating that this cannot be the explanation for incompetence in neurite extension. Neurite extension by neuroblastoma cells on FN results from three different and overlapping binding activities of non-PG receptors on the cell surface--RGDS-dependent binding to integrin, an RGDS-independent mechanism (perhaps a cell type-specific domain), and a ganglioside-dependent process. However, these neurite-extending reactions can be modulated either by exogenous addition of proteoglycans acting in a "trans" manner with the cell surface or by endogenous HG-PG acting in a "cis" manner with one or more of these receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Axons↗
PubMedDate not supplied

Laparoscopic/endoscopic repair of rectal stricture.

Although uncommon, anastomotic stricture after low anterior resection may require additional repair beyond dilatation. Two alternate approaches are described wherein laparoscopic and endoscopic techniques were utilized to avoid repeat pelvic surgery in two cases. These can be used whether a stapled or hand-sewn approach was used for the initial anastomosis. Photo documentation demonstrates a widely patent anastomosis after repair. There is early return of bowel function by these methods, and long-term results (3 years) are excellent.

Adenocarcinoma↗
PubMedDate not supplied

The effects of different routes of injection on the biochemistry of adhesion site proteoglycans in metastatic v-Ki-ras-transformed 3T3 cells.

This study compared HSPG and CSPG in adhesion sites of isogenic metastatic lung tumor cells (v-Ki-ras-transformed 3T3 cells) after injection by different routes (IV and footpad) into athymic nude mice. The proportion of HSPG was significantly greater in experimental lung metastatic cell (IV injection) than in spontaneously metastatic cells. The proportion of CSPG in these two groups of metastatic lung cells did not differ significantly. In addition, the proportion of HSPG and CSPG in spontaneously metastatic lung tumor cells was similar, unlike experimental metastatic tumor cells.

Animals↗