Biodegradation of 1,4-dioxane in planted and unplanted soil: effect of bioaugmentation with Amycolata sp. CB1190.

1,4-Dioxane is one of the most recalcitrant and toxic contaminants in the subsurface. This study investigated the potential to enhance dioxane biodegradation in both planted and unplanted soil, by adding the dioxane-degrading actinomycete, Amycolata sp. CB1190. Dioxane was not removed within 120 days in sterile controls or in viable microcosms not amended with CB 1190. Poplar root extract (40 mg/L as COD) stimulated dioxane degradation in bioaugmented soil, and 100 mg/L dioxane were removed within 45 days. Other co-substrates that enhanced dioxane degradation by CB1190 include tetrahydrofuran (THF) and 1-butanol, while glucose and soil extract did not affect dioxane degradation. The stimulatory effect of THF was partly due to enhanced enzyme induction, while that of root extract and 1-butanol was attributed to additional growth of CB1190. In another experiment with dioxane added at 10 mg/kg-soil. reactors planted with hybrid poplar trees removed (by evapotranspiration and biodegradation in the root zone) more dioxane within 26 days than unplanted reactors, regardless of whether CB1190 was added. Nevertheless, CB1190 enhanced mineralization of [14C]-dioxane in all experiments. This enhancement was more pronounced in unplanted soil because plant uptake reduced the availability of dioxane for microbial degradation. These results suggest that bioaugmented phytoremediation is an attractive alternative to remove dioxane from shallow contaminated sites.

Blockade of T lymphocyte costimulation with cytotoxic T lymphocyte-associated antigen 4-immunoglobulin (CTLA4Ig) reverses the cellular pathology of psoriatic plaques, including the activation of keratinocytes, dendritic cells, and endothelial cells.

Efficient T cell activation is dependent on the intimate contact between antigen-presenting cells (APCs) and T cells. The engagement of the B7 family of molecules on APCs with CD28 and CD152 (cytotoxic T lymphocyte-associated antigen 4 [CTLA-4]) receptors on T cells delivers costimulatory signal(s) important in T cell activation. We investigated the dependence of pathologic cellular activation in psoriatic plaques on B7-mediated T cell costimulation. Patients with psoriasis vulgaris received four intravenous infusions of the soluble chimeric protein CTLA4Ig (BMS-188667) in a 26-wk, phase I, open label dose escalation study. Clinical improvement was associated with reduced cellular activation of lesional T cells, keratinocytes, dendritic cells (DCs), and vascular endothelium. Expression of CD40, CD54, and major histocompatibility complex (MHC) class II HLA-DR antigens by lesional keratinocytes was markedly reduced in serial biopsy specimens. Concurrent reductions in B7-1 (CD80), B7-2 (CD86), CD40, MHC class II, CD83, DC-lysosomal-associated membrane glycoprotein (DC-LAMP), and CD11c expression were detected on lesional DCs, which also decreased in number within lesional biopsies. Skin explant experiments suggested that these alterations in activated or mature DCs were not the result of direct toxicity of CTLA4Ig for DCs. Decreased lesional vascular ectasia and tortuosity were also observed and were accompanied by reduced presence of E-selectin, P-selectin, and CD54 on vascular endothelium. This study highlights the critical and proximal role of T cell activation through the B7-CD28/CD152 costimulatory pathway in maintaining the pathology of psoriasis, including the newly recognized accumulation of mature DCs in the epidermis.

Procurement of population-based cancer tissue in Iowa.

We describe the first systematic survey of pathology laboratories serving Iowans to assess attitudes concerning assistance with cancer research efforts. Previous reports suggested that pathologists are reluctant to loan slides and/or paraffin tissue blocks for research purposes because of potential loss or damage, medicolegal concerns, or lack of compensation for time and effort spent in retrieving materials. In this study, we obtained survey responses from laboratory directors of 54 of the 56 pathology laboratories serving Iowans. The survey covered issues related to the availability of research materials, reimbursement for the retrieval of materials, and turnaround time for returning borrowed materials. Contrary to previous reports, we found that the laboratory directors surveyed were willing to loan slides and blocks for research purposes, provided that confidentiality is maintained, that the materials are handled properly and returned in a timely manner, and that compensation is provided.

CTLA4Ig-mediated blockade of T-cell costimulation in patients with psoriasis vulgaris.

Engagement of the B7 family of molecules on antigen-presenting cells with their T cell-associated ligands, CD28 and CD152 (cytotoxic T lymphocyte-associated antigen-4 [CTLA-4]), provides a pivotal costimulatory signal in T-cell activation. We investigated the role of the CD28/CD152 pathway in psoriasis in a 26-week, phase I, open-label dose-escalation study. The importance of this pathway in the generation of humoral immune responses to T cell-dependent neoantigens, bacteriophage phiX174 and keyhole limpet hemocyanin, was also evaluated. Forty-three patients with stable psoriasis vulgaris received 4 infusions of the soluble chimeric protein CTLA4Ig (BMS-188667). Forty-six percent of all study patients achieved a 50% or greater sustained improvement in clinical disease activity, with progressively greater effects observed in the highest-dosing cohorts. Improvement in these patients was associated with quantitative reduction in epidermal hyperplasia, which correlated with quantitative reduction in skin-infiltrating T cells. No markedly increased rate of intralesional T-cell apoptosis was identified, suggesting that the decreased number of lesional T cells was probably likely attributable to an inhibition of T-cell proliferation, T-cell recruitment, and/or apoptosis of antigen-specific T cells at extralesional sites. Altered antibody responses to T cell-dependent neoantigens were observed, but immunologic tolerance to these antigens was not demonstrated. This study illustrates the importance of the CD28/CD152 pathway in the pathogenesis of psoriasis and suggests a potential therapeutic use for this novel immunomodulatory approach in an array of T cell-mediated diseases.

Pilot evaluation of 15-deoxyspergualin for refractory acute renal transplant rejection.

15-deoxyspergualin (DSG) is a novel immunosuppressant which has been shown to be effective in preventing and treating rejection in animal allo- and xenotransplant models. Preliminary clinical studies suggest that DSG is an effective antirejection agent. In our study, 4 patients with biopsy-proven rejection episodes that were resistant to steroid and antibody therapy were then treated with DSG. All 4 rejection episodes responded to DSG therapy and all 4 kidneys continue to function (follow-up 7-15 months). However, 2 patients had additional rejection episodes after DSG therapy. Side effects during DSG treatment were minimal; 1 patient, who had also had multiple courses of antibody, developed a lymphoproliferative tumor 2 months after DSG administration. We conclude that DSG is effective in treating refractory renal transplant rejection episodes. Additional studies are necessary to determine the ideal place for DSG in treating renal transplants recipients with rejection.

Insulin independence in type I diabetes after transplantation of unpurified islets from single donor with 15-deoxyspergualin.

Islet transplantation has been slow to develop as a therapy for type I diabetes mellitus. Conventional immunosuppression does not protect islet allografts from early failure and by current techniques the yield of purified islets from a single pancreas is inadequate or only marginally in excess of the number needed to sustain normoglycaemia. We transplanted unpurified islets from a single pancreas concomitantly with a kidney to two uraemic diabetic patients. The novel agent 15-deoxyspergualin, along with antilymphocyte globulin, was used for induction immunosuppression, and azathioprine, prednisone, and cyclosporin for maintenance. Islet function has been sustained in both, and the second patient is insulin-independent and euglycaemic more than 6 months after transplantation.

Teniposide in adult solid tumors: a historical perspective.

Teniposide and etoposide are third-generation semi-synthetic derivatives of epipodophyllotoxin. Following the initial clinical introduction of teniposide in the 1970s, investigations focused almost exclusively on its analogue, etoposide, because of its formulation, which was felt to have advantages in addition to oral administration. Despite consistently inadequate dosing and scheduling, early phase I and II trial results with teniposide were promising, and current trends encourage a second look. The substantial antitumor activity of teniposide is comparable with that of etoposide, and clinical interest was rekindled when it was shown to have considerable activity against small cell lung cancer (SCLC). In view of the inadequacy of early trials and the premature cessation of clinical study, it is recommended that teniposide be reevaluated for its activity against malignant lymphomas, Hodgkin's disease, leukemias, and SCLC, against all of which its early results were encouraging. In addition, consideration should be given to its activity against brain tumors, neuroblastomas and other childhood solid tumors, and ovarian cancer; its potential value against gastric, hepatocellular, breast, and bladder cancers also should be investigated. Other areas that warrant further study include elucidation of the exact mechanism of action of teniposide, its role in both single- and multiple-agent chemotherapeutic regimens, and resolution of its optimal dose and schedule. Finally, it is suggested that with new routes of administration and improved formulations, teniposide may be expected to play a significant role in the treatment of malignant lymphomas, SCLC, and pediatric lymphocytic leukemia and neuroblastoma.

Treatment of AIDS and AIDS-related complex with 2',3'-dideoxyinosine given once daily.

In a phase I dosage-finding trial, 2',3'-dideoxyinosine (didanosine; ddI) was administered once daily to 36 patients with AIDS or AIDS-related complex for up to 65 weeks (mean, 32.1 weeks) at six dosage levels. Thirteen of 18 patients previously treated with zidovudine had developed hematologic intolerance. The maximal tolerated dosage of ddI was 12 mg/(kg.d); dose-limiting toxicities were pancreatitis and peripheral neuropathy. Other toxicities included elevation in hepatic transaminase levels, rash, cardiac conduction abnormality, and asymptomatic hyperuricemia. Eighty-six percent of patients who completed 6 weeks of treatment showed improvement in constitutional symptoms and significant weight gain. In patients treated with ddI, the mean number of CD4+ lymphocytes increased from 124/mm3 at baseline to 199/mm3 at 24 weeks (P = .0027) and the mean leukocyte count, total lymphocyte count, and hemoglobin level showed increases (all P less than .01) after 12 weeks. Serum levels of viral p24 antigen decreased greater than or equal to 50% in 14 of 19 assessable patients. No differences between the responses of patients previously treated with zidovudine and those of zidovudine-naive patients were observed. These results indicate that ddI has significant antiretroviral activity in vivo and a toxicity profile different from that of zidovudine.

Overexpression of metallothionein confers resistance to anticancer drugs.

Resistance to antineoplastic agents is the major obstacle to curative therapy of cancer. Tumor cell lines with acquired resistance to the antineoplastic agent cis-diamminedichloroplatinum(II) overexpressed metallothionein and demonstrated cross-resistance to alkylating agents such as chlorambucil and melphalan. Human carcinoma cells that maintained high levels of metallothionein because of chronic exposure to heavy metals were resistant to cis-diamminedichloroplatinum(II), melphalan, and chlorambucil. Furthermore, cells transfected with bovine papilloma virus expression vectors containing DNA encoding human metallothionein-IIA were resistant to cis-diamminedichloroplatinum(II), melphalan, and chlorambucil but not to 5-fluorouracil or vincristine. Thus, overexpression of metallothionein represents one mechanism of resistance to a subset of clinically important anticancer drugs.

Identification of an anionic form of glutathione transferase present in many human tumors and human tumor cell lines.

Glutathione transferase (GST) activity and GST isoenzyme composition have been determined for 24 human neoplasms and 6 human tumor cell lines. Substantial activity (40-1010 milliunits/mg protein) was identified in all tumor specimens examined and three of the tumor cell lines. Three tumor cell lines, the human small cell carcinoma line SW2-10S, the Burkitt's lymphoma derived cell line Raji, and the human breast carcinoma cell line MCF-7, contained minimal GST activity. Although the small size of the tumor samples precluded isoenzyme analysis by substrate specificities, analysis of GST activity following sample separation by isoelectric focusing indicated that the predominant (comprising at least 70% of the 1-chloro-2,4-dinitrobenzene-conjugating activity) GST isoenzyme in each of these primary tumor (17 of 17) and tumor cell line (3 of 3) extracts was anionic (isoelectric point, 4.5-4.8). In three tumor samples, adenocarcinomas of the lung, colon, and stomach, analysis by isoelectric focusing identified minor but detectable (10-20% of total) cationic GST. The anionic form of GST has been purified to homogeneity from three primary human tumors: a malignant melanoma; a mesothelioma; and a breast carcinoma. GST from these tumors consists of two subunits each of Mr 25,200. On Western blot analysis, antibodies raised against the anionic GST purified from mesothelioma detect protein of Mr approximately 25,000 in extracts of both normal kidney and tumors containing anionic GST activity but not in extracts of human liver that did not contain detectable anionic activity. The amino acid compositions of these proteins were quite similar to that previously described for GST-pi and the amino-terminal amino acid sequences for these tumor-derived isoenzymes are identical to one another and to that previously described for GST-pi from human placenta. GST is a major enzymatic activity in many human malignancies, comprising as much as 3% of the cytosolic protein of some tumors. Anionic GST is the predominant form of glutathione transferase activity in many human tumors and human tumor cell lines. In selected tumor samples the predominant anionic GST isoenzyme has been identified as a member of the pi class of this enzyme family. In addition, at least 3 of 17 tumor samples contained lesser but detectable amounts of cationic GST, probably of the alpha class. By conjugating glutathione with electrophilic anticancer drugs, the substantial levels of GST in human tumors may have a role in the innate or acquired resistance of these neoplasms to anticancer therapy.

Pharmacokinetics of dibromodulcitol in humans: a phase I study.

A combined clinical and pharmacokinetic phase I study of the substituted hexitol dibromodulcitol (DBD), administered as a single oral monthly dose, has been performed. Twenty-three patients with advanced neoplasms received DBD doses ranging from 600 to 1,800 mg/m2 body surface area (BSA). The dose-limiting toxicity was myelosuppression, with both significant granulocytopenia and thrombocytopenia occurring at dose levels of 1,500 to 1,800 mg/m2. The average pharmacokinetic parameters for DBD, calculated on the basis of a one-compartment model with first-order absorption and elimination, include the elimination constant, .005 +/- .002/min; absorption constant, .012 +/- .009/min; and an apparent volume of distribution, 1.03 +/- .4 L/kg. The area under the drug concentration curve (AUC) and the peak drug level (Cmax) were linearly related to the dose administered (P less than .001). The mean AUC was 18.7 +/- 6.1 mmol/L min, and the mean Cmax was 47.1 +/- 16.8 mumol/L when normalized to a DBD dose of 1 gm/m2. The elimination constant was significantly reduced in patients with abnormal hepatic function (P less than .01). The elimination constant was not correlated with renal function. The half-life of DBD in plasma (158 minutes) was considerably shorter than the four-to eight-hour half-life of total radioactivity in plasma measured by previous investigators following the administration of radiolabeled DBD.

Trial of droperidol as an antiemetic in cisplatin chemotherapy.

A trial of droperidol as an antiemetic was undertaken during 48 courses of cisplatin chemotherapy in 31 patients with cancer. The optimal loading dose was 10 mg iv, with a maintenance dose of 4 mg iv every 2 hours for four additional doses. Beyond this level, cardiovascular side effects became problematic.

Assay for mitolactol and its bifunctional alkylating metabolites in plasma.

A method involving precolumn derivatization and high-performance liquid chromatography is described for the measurement of mitolactol levels in plasma. The basis of the assay is the reaction at pH 7.4 and 50 degrees C of mitolactol with diethyldithiocarbamate to form 1,6-bis(diethyldithiocarbamoyl)-2,3,4,5-tetrahydroxyhexane. This derivative is then extracted into chloroform, resolved by normal-phase chromatography, and detected by UV (254 nm) absorbance. The method quantitates the sum of mitolactol and its active bifunctional metabolites, bromoepoxydulcitol and dianhydrogalactitol, in plasma down to concentrations of 0.5 microM. The pharmacokinetic parameters of the drug in mice have been determined following the intraperitoneal injection of either 20 or 100 mg/kg of body weight. Absorption from the peritoneal cavity was largely complete by 5 min. Parameters obtained include a first-order elimination constant, k = 0.92 X 10(-2) min-1 and an apparent volume of distribution, Vd = 0.78 L/kg. For a 100-mg/kg dose, the area under the concentration-time curve was 49 mM X min, and the mean peak drug concentration was reached at 40 min following intraperitoneal injection. Concentrations of mitolactol in total plasma and in plasma ultrafiltrates were identical, indicating that the drug is not (less than 4%) reversibly bound to plasma proteins.

Relationship in very elderly veterans of nutritional status, self-perceived chewing ability, dental status, and social isolation.

The relationship of nutritional status, self-perceived chewing ability, dental status, and social isolation was examined. Seventy-three ambulatory, elderly (means = 86 years) veterans were studied. Parameters of nutritional status included intakes of protein, carbohydrate, fat, and total calories, and hemoglobin, serum albumin, total lymphocyte count, and height/weight ratio were determined. Dental status was measured, and self-perceived chewing problems and social isolation were assessed by interview. Results showed a significant correlation between perceived chewing problems and diminished protein and total caloric intake and increased carbohydrate intake. No association was found between measured dental status and nutritional status. Social isolation was weakly correlated with greater protein and calorie intake. These results support the contention that the presence of self-perceived chewing problems are more reliable than the quality of the dentition itself as an indicator of altered nutritional status.

Carcinoma of unknown primary site. A prudent approach.

The patient with carcinoma of unknown primary site deserves prompt and efficient evaluation in an effort to locate a primary tumor in a treatable location. Early collaboration between clinician and pathologist is essential. The needs of patient and family must be considered, and the hospital stay should not be extended by unnecessary diagnostic tests that have no purpose other than delineation of extent of disease. Specific chemotherapy regimens should be instituted if evaluation reveals a potentially responsive tumor. All patients should receive palliative therapy directed at relief of symptoms and pain and improved quality of life. Refinement of immunologic and cytochemical techniques for primary tumor site localization, along with advances in the therapy of colonic, pancreatic, lung, and ovarian carcinomas, should make the outlook for the patient with carcinoma with an occult primary site considerably brighter.