Search PubMed⌕ Search

Biomedical subjects

J L Collins

Publications and source records attributed to J L Collins.

At least 91 records · Page 5Linked to original sources
PubMed1991

Inhibition of protein synthesis enhances the lytic effects of tumor necrosis factor alpha and interferon gamma in cell lines derived from gynecological malignancies.

Few clinical responses have occurred in preliminary studies using the cytokines tumor necrosis factor alpha (TNF alpha) or interferon gamma (IFN gamma) in cancer patients. This may be related to the observation that many malignant cell lines are resistant to lysis by these cytokines in vitro. Resistance to lysis by TNF alpha or IFN gamma in many cells is controlled by a protein-synthesis-dependent mechanism, such that when protein synthesis is inhibited cells become sensitive to lysis by these cytokines. Because there is some evidence that TNF alpha and IFN gamma act through different lytic mechanisms and are opposed by different resistance mechanisms, we treated a panel of eight cell lines, five derived from human cervical carcinomas (ME-180, MS751, SiHa, HT-3, and C-33A) and three derived from ovarian carcinomas (Caov-3, SK-OV-3, and NIH: OVCAR-3) with both TNF alpha and IFN gamma to determine whether such combination treatment might maximize in vitro cell lysis. Our results showed that pretreatment with IFN gamma followed by exposure to TNF alpha in the presence of protein synthesis inhibitors increased lysis of seven of the eight cell lines above that seen with either TNF alpha or IFN gamma and inhibitors of protein synthesis. Only the cell line C-33A was resistant to lysis by TNF alpha and IFN gamma, when exposed to these agents both alone and in combination with protein synthesis inhibitors. Clinically, combining the cytokines TNF alpha and IFN gamma with protein synthesis inhibitors may maximize the in vivo lytic effects of these cytokines.

Cell Line↗
PubMed1991

Tumor necrosis factor alpha is elevated in the peritoneal fluid from women with ruptured ectopic pregnancies.

The purpose of this study was to determine whether exposure of the peritoneum to fetal tissue is associated with elevated tumor necrosis factor alpha (TNF alpha) levels in the peritoneal cavity. We measured TNF alpha levels in the peritoneal fluids and serum from women with ruptured ectopic, unruptured ectopic and intrauterine pregnancies, as well as nonpregnant women undergoing tubal ligation. The results showed that patients with ruptured ectopic pregnancies were more likely to have TNF alpha levels in the peritoneal fluid greater than 40 units/ml (68%), compared with women with unruptured ectopic or intrauterine pregnancies (21%) (p less than 0.05, Fisher exact test). No elevation of peritoneal fluid TNF alpha levels was found in nonpregnant patients. Because TNF alpha is primarily a product of activated macrophages, it is likely that elevated TNF alpha levels in the peritoneal fluid of women with ruptured ectopic pregnancies reflects activation of peritoneal macrophages.

Adolescent↗
PubMed1991

Serum CA-125 levels in women with ectopic and intrauterine pregnancies.

In women with ectopic pregnancies the extrauterine compartments are exposed to fetal tissue. Since such tissue is known to express CA-125, we measured serum levels of CA-125 in patients with ectopic pregnancies and compared them to those in patients with intrauterine pregnancies. A total of 44 pregnant women were included in the study; all were in the first trimester. Twenty-seven of them had ectopic pregnancies, and 17 had intrauterine ones. Our results show that women with ectopic pregnancies, ruptured or unruptured, were more likely to have elevated levels of serum CA-125 than were women who had intrauterine pregnancies.

Adult↗
PubMed1991

In vitro study of simultaneous infusion of incompatible drugs in multilumen catheters.

Multilumen catheters are commonly used to simultaneously administer incompatible drugs to critically ill patients. Though there are no known documented reports that this practice has been responsible for harmful events in patients, likewise there are no published data to verify the safety and efficacy of this practice. This study utilized an in vitro model flow system to examine the physicochemical phenomena that occur when two incompatible drugs (phenytoin and total parenteral nutrition) are simultaneously administered through multilumen catheters. Flow conditions and drug infusions in the venous model were designed to mimic the in vivo clinical situation to evaluate two central venous catheter types, a double- and a triple-lumen catheter. Video recordings were made of drug interactions, and assays of phenytoin concentration were performed on samples of the circulating fluid. White clouds of phenytoin precipitation were observed near the tip of the double-lumen catheter but not the triple-lumen catheter. Infusion through the double-lumen catheter resulted in an average of 6% loss of phenytoin to precipitate, which, on microscopic examination, appeared as spindle-shaped crystals 25 to 50 microns in length and 5 to 10 microns wide. In some cases, millimeter-size fragments of phenytoin precipitate were seen to dislodge from the tip of the double-lumen catheter. The adjacent orifices at the tip of the end hole of the double-lumen catheter appeared to permit interaction of the two effusing streams of the incompatible drugs, whereas the staggered orifices of the triple-lumen catheter reduce this interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization, Central Venous↗
PubMed1990

Expression of a resistance mechanism in ovarian and cervical carcinoma cells prevents their lysis by gamma-interferon.

Despite extensive evidence that recombinant human gamma-interferon (IFN-gamma) exerts antiproliferative effects on a variety of cancer cell lines, IFN-gamma has not been shown to lyse cells in vitro. In order to determine whether some cancer cells might actively resist lysis by IFN-gamma, we examined eight arbitrarily selected cell lines derived from gynecological malignancies (ME-180, MS751, HT-3, SiHa, and C-33A human cervical carcinoma lines; Caov-3, SK-OV-3, and NIH:OVCAR-3 human ovarian carcinoma cell lines) for lysis by IFN-gamma. In a 24-h assay involving release of 51Cr from cells, none of these cell lines was lysed by IFN-gamma, either alone or in combination with actinomycin-D or emetine, two inhibitors of protein synthesis. However, pretreatment of cells with 100 units/ml of IFN-gamma for 24 h, followed by inhibition of protein synthesis, led to significantly increased lysis of the cell lines ME-180, MS751, and Caov-3. These results indicate that IFN-gamma induces a lytic mechanism in some cancer cells that is opposed by a protein synthesis-dependent resistance mechanism. This suggests that a combination therapy involving IFN-gamma and inhibitors of protein synthesis may be useful in the treatment of some cancers.

Cell Line↗
PubMed1990

Dexamethasone used as an antiemetic in chemotherapy protocols inhibits natural cytotoxic (NC) cell activity.

Because dexamethasone is often included as an antiemetic in chemotherapy protocols that involve cisplatin and because cisplatin has been shown to increase the in vitro lysis of tumor cells by natural cytotoxic (NC) effector cells, we determined the NC activity of 27 patients who received dexamethasone in conjunction with seven different cisplatin-based chemotherapy protocols. The results of this analysis showed that the NC activity of patients who received cisplatin-based chemotherapy protocols that included dexamethasone was reduced significantly 24 hours after treatment compared with before treatment (P less than 0.001). The addition of dexamethasone (at a concentration equivalent to the plasma level of patients treated with dexamethasone) to the in vitro assay of NC activity caused a significant decrease in NC activity compared with when dexamethasone was not added (P less than 0.001). There was no cumulative effect of dexamethasone in that the reduction of NC activity by dexamethasone was not significantly different in patients who had been treated previously at least four times and in patients who were treated for the first time. When dexamethasone was not included in the chemotherapy protocol the NC activity of 19 patients was not reduced 24 hours after treatment. These results indicate that dexamethasone causes a significant reduction in NC activity. Although the tumor surveillance role of human NC cells in vivo has not been established, the effect of dexamethasone on NC cells suggests that additional research of the effect of dexamethasone in cisplatin-based chemotherapy protocols is warranted.

Adult↗
PubMed1990

Common expression of a tumor necrosis factor resistance mechanism among gynecological malignancies.

The efficacy of tumor necrosis factor alpha (TNF alpha) as an anticancer agent is limited. This limitation might be related to the expression of a protein-synthesis-dependent resistance mechanism that prevents the lysis of tumor cells by TNF alpha. To test this possibility eight randomly selected human cell lines, three derived from ovarian carcinomas and five derived from cervical carcinomas, were tested for their in vitro sensitivity to TNF alpha-mediated lysis. The results of this analysis showed that all eight cell lines are normally resistant to lysis by TNF alpha. However, in the presence of inhibitors of protein synthesis, seven of them showed a significant increase in TNF alpha-mediated lysis. Measurement of protein synthesis showed that there is a linear correlation between the level of inhibition of protein synthesis and the level of TNF alpha-mediated lysis. The fact that seven of eight randomly selected cell lines are resistant to TNF alpha because they express a protein-synthesis-dependent resistance mechanism suggests that this mechanism of resistance may be common among gynecological cancers. The results also suggest that a therapy involving TNF alpha and inhibitors of protein synthesis might be useful for the treatment of gynecological malignancies.

Antibodies, Neoplasm↗
PubMed1990

Proliferative and antiproliferative effects of interferon-gamma and tumor necrosis factor-alpha on cell lines derived from cervical and ovarian malignancies.

Four human cell lines derived from cervical carcinomas (ME-180, SiHa, HT-3, and MS751) and three human cell lines derived from ovarian carcinomas (SK-OV-3, Caov-3, and NIH:OVCAR-3) were analyzed in vitro to determine the effect of recombinant interferon-gamma and recombinant human tumor necrosis factor-alpha on cell growth and survival. The effects of interferon-gamma, tumor necrosis factor-alpha, and both interferon-gamma and tumor necrosis factor-alpha on cell growth were measured after 24 and 72 hours of incubation by the incorporation of chromium 51. The results of this analysis showed that all seven cell lines were resistant to the antiproliferative action of tumor necrosis factor-alpha, that the growth of most cell lines was inhibited by interferon-gamma by 72 hours of incubation, and that after 72 hours of incubation all cell lines demonstrated a synergistic antiproliferative response to the combination of interferon-gamma and tumor necrosis factor-alpha. However, the effects of these cytokines on cell growth were found to differ among cell lines and varied with the concentration and the duration of incubation. The growth of one cell line (Caov-3) was stimulated by both tumor necrosis factor-alpha and interferon-gamma. These results suggest that the clinical effects of these cytokines on the growth of gynecologic cancers may be more complex than previously supposed.

Cell Division↗
PubMed1990

Reduced natural cytotoxic cell activity in patients receiving cisplatin-based chemotherapy and in mice treated with cisplatin.

In mice natural cytotoxic (NC) cells are known to play a role in the rejection of tumours that are sensitive to NC-mediated lysis. We have recently shown that in vitro human and murine tumour cells become more sensitive to lysis mediated by NC cells in the presence of the anti-cancer drug cisplatin. If NC activity plays a role in tumour surveillance in humans, then the ability of NC cells to eliminate tumours in patients treated with cisplatin would not only be dependent on cisplatin increasing the sensitivity of tumours to NC mediated lysis, but would also depend on the maintenance of high levels of NC activity during chemotherapy. Here we report that patients receiving chemotherapy that included cisplatin showed a time-dependent reduction in NC activity. NC activity was normal 1 day after treatment; however, 15 days after treatment patients had an eight- to 16-fold reduction in NC activity that returned to normal levels by day 21. The reduction in NC activity of patients was coincident with a reduction in circulating monocytes. Mice treated with only cisplatin showed a similar reduction in NC activity. Mice treated with cisplatin had a reduced level of NC activity that was first apparent 8 days after treatment, reached a nadir on day 15, and returned to normal levels on day 22.

Adult↗
PubMed1989

The anticancer drug, cisplatin, increases the naturally occurring cell-mediated lysis of tumor cells.

It has been proposed that a component of the antitumor potential of the chemotherapeutic agent, cisplatin, resides in the host's ability to respond to cisplatin-treated tumor cells. Here we report that tumor cells that are normally resistant to lysis mediated by naturally occurring cytotoxic cells showed an increased sensitivity to lysis mediated by murine spleen cells or human peripheral blood monocytes and lymphocytes when cisplatin was added at the beginning of the lytic assay. This was shown for the lysis of both murine and human tumor cells. The pretreatment of tumor cells, but not effector cells with cisplatin caused an increase in lysis in the presence of murine spleen cells or human peripheral blood leukocytes, indicating that the effect of cisplatin is to reduce resistance to lysis by these effector cells. The lysis of tumor cells by naturally occurring cytotoxic cells was blocked by antibodies specific for tumor necrosis factor. In addition, the ability of cisplatin to increase lysis was seen with cells that are sensitive to natural cytotoxic cells, but not with cells that are sensitive to natural killer cells. These results suggest that the effector cells that mediate the lysis of these tumor cells in the presence of cisplatin are likely to be natural cytotoxic cells. The ability of cisplatin to increase the lysis of tumor cells by naturally occurring cytotoxic cells indicates that these cells may be a host defense mechanism that contributes to the anticancer potential of cisplatin.

Adjuvants, Immunologic↗
PubMed1989

Daunorubicin conjugated to a monoclonal anti-CA125 antibody selectively kills human ovarian cancer cells.

The present study was designed to test the in vitro efficacy for human ovarian cancer cells of daunorubicin (DNR) conjugated to a monoclonal antibody (OC125). The OC125 antibody specifically binds to the antigenic protein CA125 from human ovarian carcinoma. New analogs of DNR containing various linker groups were conjugated to mouse monoclonal anti-CA125 antibody (DNR-OC125); nonspecific murine IgG1 (DNR-IgG1); or bovine serum albumin (DNR-BSA). The DNR-protein conjugates were all stable for several days in neutral solutions at room temperature. The DNR-OC125 conjugates selectively killed dividing cell populations but not nondividing cell populations of two human ovarian cancer cell lines (SK-OV-3 or OVCAR-3) that express the CA125 antigen. Equivalent concentrations of DNR-IgG1 or DNR-BSA conjugates were neither toxic to the dividing nor the nondividing populations of SK-OV-3 or OVCAR-3 cells. Only those DNR-protein conjugates linked to OC125 were cytotoxic to dividing cell populations of both cell lines. This indicates that cytotoxicity is dependent on OC125 antibody-CA125 antigen binding which concentrates DNR on the ovarian cancer cells. We advance the hypothesis that following antibody-antigen binding, DNR is released from the conjugate and it intercalates in DNA by a mechanism similar to that of the unmodified DNR. The new DNR-OC125 conjugate may be useful for delivering DNR to ovarian tumors that express the CA125 antigen because the drug-antibody conjugates (1) retain the cytotoxic characteristics of the unmodified drug: (2) specifically kill the human ovarian cancer cells that express the CA125 antigen; and (3) are completely stable for days in neutral solutions at room temperature.

Adenocarcinoma↗
PubMed1989

In vitro analysis of the anticancer potential of tumor necrosis factor in combination with cisplatin.

We have recently shown that cisplatin increases the natural cytotoxic (NC) cell-mediated lysis of a variety of human adenocarcinoma cell lines that are resistant to cisplatin or NC activity alone. Because NC lysis is mediated by tumor necrosis factor alpha (TNF) bound to the surface of NC effector cells, we analyzed the ability of TNF in combination with cisplatin to increase the lysis of tumor cells. The in vitro anticancer potential of the combination of TNF and cisplatin was determined for both dividing and nondividing populations of two human ovarian carcinoma cell lines, SK-OV-3 and OVCAR-3. Nondividing SK-OV-3 and OVCAR-3 cells are resistant to cisplatin and TNF when used as single agents. Dividing OVCAR-3 cells are approximately two times more sensitive to TNF than dividing SK-OV-3 cells, whereas dividing SK-OV-3 cells are approximately ten times more sensitive to cisplatin than dividing OVCAR-3 cells. TNF at 1000 units/ml in the presence of clinically low concentrations of cisplatin (0.6-0.25 micrograms/ml) increased the lysis of dividing OVCAR-3 cells above the value expected for the sum lysis mediated by cisplatin alone and lysis mediated by TNF alone. Similar results were obtained with dividing populations of the SK-OV-3 cell line. The combination of cisplatin and TNF did not increase the lysis of the nondividing populations of either cell line. The increased lysis of tumor cells combined with the maintenance of specificity for only dividing cells indicates that the combination of cisplatin and TNF may be useful for the treatment of tumors that are resistant to either cisplatin or TNF.

Adenocarcinoma↗
PubMed1989

Enzyme immune assay determination of CA-125 in serum, peritoneal fluid, and follicular fluid from women with minimal endometriosis after ovarian hyperstimulation.

We conclude that the acutely preovulatory expression of CA-125 in serum and FF as determined by EIA is low and not significantly enhanced by OH. Although the PF concentrations were elevated in women with minimal endometriosis when compared with women without endometriosis, the still unresolved problem associated with measurements of CA-125 in PF for both RIA and EIA and the considerable overlap in individual values between both patient groups preclude its use as a reliable screening or monitoring parameter, at least for the present.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

A rapid in vitro screening system for the identification and evaluation of anticancer drugs.

We report the development of an in vitro screening system that can be used to identify new anticancer drugs that are specifically cytotoxic for dividing cells. The screening system takes advantage of the potential of many cell lines, including tumor cells, to stop dividing when they are plated at high cell density. The cytotoxic effects of anticancer drugs on dividing (i.e., cells plated at low cell density) and nondividing cells (i.e., cells plated at high cell density) is measured by the incorporation of 51Cr. This in vitro system was evaluated by measuring the cytotoxic effects of the anticancer drugs cisplatin, thiotepa, doxorubicin, methotrexate, and vinblastine on the cell lines B/C-N, ME-180, and MCF-7. In this in vitro system the concentrations of the anticancer drugs that produced significant cytotoxicity on only dividing cells are similar to the concentrations that are used clinically. The fact that this in vitro system is rapid, simple, applicable to many cell types, and able to predict effective concentrations of anticancer drugs should make it useful for the screening of new anticancer drugs and for the design of preclinical studies.

Animals↗
PubMed1988

Anti-tumor surveillance of non-contact-inhibited transformed cell lines.

In order to determine if the correlated expression of transformation and tumorigenicity is affected by the agents used to induce transformants or by the immune status of the host used to test the tumorigenicity of transformants, we derived a series of cloned cell lines from foci of transformed cells induced by treatment of the contact-inhibited mouse cell line B/C-N7.ICI with the DNA demethylating agent 5-azacytidine (5-AZC) or the DNA demethylating and mutating agent benzo(a)pyrene dihydrodiol epoxide (BPDE). The transformed cell lines were injected into syngeneic nude and normal mice to determine their tumorigenicity. The results of this analysis showed that 93% of the transformants induced by 5-AZC treatment grew as tumors when injected into nude mice. Of those lines capable of growing as tumors in nude mice, 86% were also tumorigenic when injected into normal mice. In contrast, only 64% of BPDE-induced transformants grew as tumors in nude mice, and of those, only 44% were also tumorigenic in normal mice. The existence of non-contact-inhibited transformants that are tumorigenic only in nude mice indicates that host anti-tumor immune surveillance mechanisms are operative in normal mice. Further, the difference in both the percentage of transformed cell lines that are tumorigenic and the percentage of tumorigenic transformants that are susceptible to immune surveillance when transformants are induced by BPDE as compared to 5-AZC indicates that the transforming agent can affect both the correlation between the expression of transformation and tumorigenicity, and the interaction between the immune system and tumorigenic transformants.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1988

Tumor necrosis factor in peritoneal fluid of women undergoing laparoscopic surgery.

The level of tumor necrosis factor (TNF) in peritoneal fluid (PF-TNF) of 74 women undergoing laparoscopy was determined. The difference between the mean concentration of PF-TNF of women with normal pelvic anatomy and women with moderate or severe endometriosis was significant (P less than 0.01). The proportion of PF-TNF-positive women with PID and those with moderate or severe endometriosis was also significantly higher when compared to women with normal pelvic anatomy (P less than 0.05; P less than 0.02). The proportion of PF-TNF positive women among nulligravid and nulliparous women was significantly higher than that of women with two or more pregnancies (P less than 0.01) and two or more deliveries (P less than 0.005). These results indicate that the presence of PF-TNF is associated with primary infertility and endometriosis.

Adolescent↗