Proteolysis of plasminogen activator inhibitor-1 by Yersinia pestis remodulates the host environment to promote virulence.

UNLABELLED: Essentials Effect of plasminogen activator inhibitor (PAI)-1 on plague and its Y. pestis cleavage is unknown. An intranasal mouse model of infection was used to determine the role of PAI-1 in pneumonic plague. PAI-1 is cleaved and inactivated by the Pla protease of Y. pestis in the lung airspace. PAI-1 impacts both bacterial outgrowth and the immune response to respiratory Y. pestis infection. Click to hear Dr Bock discuss pathogen activators of plasminogen. SUMMARY: Background The hemostatic regulator plasminogen activator inhibitor-1 (PAI-1) inactivates endogenous plasminogen activators and aids in the immune response to bacterial infection. Yersinia pestis, the causative agent of plague, produces the Pla protease, a virulence factor that is required during plague. However, the specific hemostatic proteins cleaved by Pla in vivo that contribute to pathogenesis have not yet been fully elucidated. Objectives To determine whether PAI-1 is cleaved by the Pla protease during pneumonic plague, and to define the impact of PAI-1 on Y. pestis respiratory infection in the presence or absence of Pla. Methods An intranasal mouse model of pneumonic plague was used to assess the levels of total and active PAI-1 in the lung airspace, and the impact of PAI-1 deficiency on bacterial pathogenesis, the host immune response and plasmin generation following infection with wild-type or ∆pla Y. pestis. Results We found that Y. pestis cleaves and inactivates PAI-1 in the lungs in a Pla-dependent manner. The loss of PAI-1 enhances Y. pestis outgrowth in the absence of Pla, and is associated with increased conversion of plasminogen to plasmin. Furthermore, we found that PAI-1 regulates immune cell recruitment, cytokine production and tissue permeability during pneumonic plague. Conclusions Our data demonstrate that PAI-1 is an in vivo target of the Pla protease in the lungs, and that PAI-1 is a key regulator of the pulmonary innate immune response. We conclude that the inactivation of PAI-1 by Y. pestis alters the host environment to promote virulence during pneumonic plague.

Histopathologic staging at initial diagnosis of mycosis fungoides and the Sézary syndrome. Definition of three distinctive prognostic groups.

STUDY OBJECTIVE: To determine the optimal staging evaluation at the time of initial diagnosis of mycosis fungoides or the Sézary syndrome. DESIGN: Retrospective review of a uniformly staged inception cohort. SETTING: Single-institution tertiary care center. PATIENTS: 152 consecutive patients who had mycosis fungoides with or without the Sézary syndrome within 6 months of the initial definitive diagnosis. INTERVENTION: A detailed staging evaluation including physical examination, routine laboratory studies, chest roentgenogram, lymphangiogram, peripheral blood smear, lymph node biopsy, bone marrow aspirate or biopsy, and liver biopsy in selected patients. MEASUREMENTS AND MAIN RESULTS: Univariate adverse prognostic features at initial diagnosis in patients with mycosis fungoides included (P less than 0.01) one or more cutaneous tumors or generalized erythroderma, adenopathy, blood smear involvement with Sézary cells, lymph node effacement, eosinophilia, and visceral involvement. Important, independent prognostic factors in a multivariate analysis are the presence of visceral disease and type of skin involvement. CONCLUSIONS: A staging system based on histopathologic evaluation of skin, lymph nodes, blood, and visceral sites provides more comprehensive prognostic information than clinical evaluation of skin disease and adenopathy. Patients may be divided at initial presentation into three prognostic groups: good-risk patients, who have plaque-only skin disease without lymph node, blood, or visceral involvement (median survival, greater than 12 years); intermediate-risk patients, who have cutaneous tumors, erythroderma, or plaque disease with node or blood involvement but no visceral disease or node effacement (median survival, 5 years); and poor-risk patients, who have visceral involvement or node effacement (median survival, 2.5 years).

A trial of combination chemotherapy followed by hormonal therapy for previously untreated metastatic carcinoma of the prostate.

We administered combination chemotherapy with cyclophosphamide, doxorubicin, and cisplatin to 25 previously untreated patients with metastatic prostate cancer in order to assess the efficacy of chemotherapy before any hormonal manipulation. Hormonal therapy was administered only after progression of disease to chemotherapy. All 25 patients were followed until time of death and all were able to receive hormonal therapy. We did not find substantially improved response rates when combination chemotherapy was applied before endocrine treatment since the 33% objective response rate to chemotherapy was only minimally higher than the response in our patients who had failed hormonal therapy and then received identical or similar chemotherapy. Furthermore, the introduction of intensive combination chemotherapy before hormonal therapy in our study did not result in any striking improvement in overall survival compared with patients who received initial hormonal therapy in many other studies. Responses to chemotherapy were not attributable to suppression of serum testosterone since all 12 patients with partial response (PR) or stable disease (SD) and four of seven patients with no response (NR) had normal testosterone levels at the time of response assessment. The initial use of chemotherapy did not adversely affect the expected high percentage of objective responses (68%) to subsequent hormonal manipulation. The frequency, duration, and quality of responses to hormonal therapy exceeded the responses to chemotherapy. The disappointing responses to chemotherapy reflect the very modest efficacy of even aggressively delivered cytotoxic agents.

Combined modality treatment of cutaneous T cell lymphoma: results of a 6-year follow-up.

Thirty-nine patients with cutaneous T cell lymphoma (CTCL; including mycosis fungoides or the Sezary syndrome) with no previous treatment other than topical therapy or oral corticosteroids, received total skin electron beam irradiation (TSEB) and either sequential or simultaneous systemic chemotherapy. Median follow-up, measured from the time of initiation of therapy to the time of analysis, is in excess of 6 years and extends to 100+ months. Thirteen patients with stage I disease (limited to skin with no adenopathy) received 3,000 rad total skin electron beam irradiation followed by three 2-week courses of daily intravenous (IV) mechlorethamine. Twenty-six patients with advanced disease (stage II-IV) received 2,400 rad of TSEB and simultaneous chemotherapy with two alternating three-drug regimens: vinblastine, doxorubicin, and bleomycin (VAB) alternating with cyclophosphamide, methotrexate, and prednisone (CMP) administered over 54 weeks. The overall response rate was 92% with 16 of 39 patients (41%) achieving a histologically documented complete response (CR). Stage I patients had a significantly increased CR rate (77%) compared with stage II-IV (P less than .01). The overall 6-year survival was 92% for stage I patients and 26% for stage II-IV patients (23%) (P less than .001). Among ten completely responding stage I patients, six remain alive and disease-free in excess of 72 months. The median disease-free survival is 26 months for completely responding stage II-IV patients (P = .04), but none are continuous disease-free survivors after protocol treatment. We conclude that combined modality treatment can be safely administered and produces prolonged disease-free survival in some stage I patients, but not in more advanced stage patients.

Computed tomography of the abdomen and pelvis: documentation of tumor response and progression in disseminated prostate cancer.

Computed tomography of the abdomen and pelvis has been used to stage early prostatic cancer. We investigated its value in monitoring tumor response in more advanced disease. Serial computed tomography of the abdomen and pelvis was obtained along with multiple other staging tests prior to treatment and at 3- to 4-month intervals thereafter in 32 patients with stage D2 tumor treated initially with combination chemotherapy and with hormones at progression. Pretreatment lymphography with follow-up abdominal films was also performed. Initial computed tomography of the abdomen and pelvis showed evidence of node metastases in 35% of patients while lymphography was positive in 54%. Among 19 patients with tumor response and 25 with progression, the results of treatment were objectively documented by improvement or worsening, respectively, in a mean of 5.1 and 5.0 other staging tests, exclusive of computed tomography. Computed tomography of the abdomen and pelvis improved in 85% of responding patients examined. Progression was confirmed by worsening of computed tomography in 32%. Although lymphography was often abnormal prior to treatment, in our hands it was not useful in serial monitoring of tumor status. We conclude that serial computed tomography of the abdomen and pelvis, when initially positive, is a useful test to document objectively tumor response and progression in disseminated prostatic cancer.

Prognostic factors in patients with hepatocellular carcinoma receiving systemic chemotherapy. Identification of two groups of patients with prospects for prolonged survival.

Among 37 patients with hepatocellular carcinoma given systemic chemotherapy, 12 (32 percent) lived 14 to 37 months from initiation of treatment whereas the remainder died within five months. Individual factors associated with improved survival included fully ambulatory performance status, lack of jaundice, response to chemotherapy, the fibrolamellar carcinoma pathologic variant, absence of cirrhosis, and normal serum alpha-fetoprotein levels. Patients living longer than 12 months fell into two groups. Seven patients with fibrolamellar carcinoma lacked evidence of hepatitis B serum markers or cirrhosis and had normal alpha-fetoprotein levels and surprisingly frequent extrahepatic metastases. All but one were Caucasians aged 25 years or less. The other five "long-term" survivors were all fully ambulatory without jaundice, and the majority were older non-Caucasians with tumor confined to the liver at the time of diagnosis and with hepatitis B markers, elevated alpha-fetoprotein levels, or cirrhosis. All patients without fibrolamellar carcinoma who were less than fully ambulatory or who had jaundice died quickly. Patients with fibrolamellar carcinoma have homogeneous clinical features, and their disease follows a relatively indolent course. In other patients with hepatocellular carcinoma, assessment of ambulatory status and serum bilirubin determination can identify those with some prospect of prolonged survival.

Phase I and pharmacokinetic study of tiazofurin (TCAR, NSC 286193) administered by continuous infusion.

Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, TCAR) is a synthetic C-nucleoside that demonstrated significant in vivo activity against a variety of animal tumors as well as in vitro activity against human tumor-derived cell lines. Thirteen patients were treated with TCAR administered as a 5-day continuous infusion in this Phase I trial. Seventeen complete cycles were administered in three dose levels ranging from 550 to 1450 mg/M2. Dose-limiting toxicities were myelosuppression and neurotoxicity including severe lethargy. Other toxicities including superficial skin peeling, myalgias, and tearing were seen at all doses. One patient had chest pain on day 4 resulting in stopping the drug, however, there was no evidence of cardiac or pericardial disease. Uric acid levels rose within one day in the absence of allopurinol treatment. There were no treatment related deaths. HPLC measurement of drug levels demonstrated steady-state plasma levels during the infusion, and a half-life following the infusion of 7.7 +/- 0.6 hours. Minor abnormalities in renal function were associated with dramatic changes in pharmacokinetics and toxicity. No clinical responses were observed in this trial.

Therapy for multiple myeloma with alternating non-cross-resistant chemotherapy combinations: heterogeneity of tumor responsiveness.

Thirty-five previously untreated patients with multiple myeloma were treated with a 60-week course of alternating, potentially non-cross-resistant chemotherapy combinations (melphalan and prednisone; vincristine, cyclophosphamide, doxorubicin, and prednisone; and carmustine, melphalan, and prednisone), alternating every 15 weeks in an attempt to prevent the development of drug resistance. The overall objective response rate (greater than 50% decrease in M protein) was 60% and six patients (17%) had a complete disappearance of the M protein. After 60 weeks, chemotherapy was discontinued in 17 responding or stable patients until relapse occurred from 4 to 39 months later (median, 12 months). Patients relapsing late (greater than 12 months after discontinuation of therapy) responded more frequently than those relapsing earlier to the reinstitution of the same chemotherapy program. The overall response rate and the actuarial median survival of 26 months in the 35 patients do not differ from the results reported recently with nonalternating combinations given until clinical tumor progression. The failure of this study to prolong survival by using alternating regimens may be due to (a) the likely possibility that the initial two regimens are not actually non-cross-resistant in most myeloma patients, and (b) the long interval between the alternating regimens, particularly in the face of the low response rate to the initial regimen of melphalan and prednisone.

Combination chemotherapy of hepatocellular carcinoma with doxorubicin and streptozotocin.

Twenty-three patients with unresectable hepatocellular carcinoma were given doxorubicin 60 mg/m2 I.V. day 1 and streptozotocin 0.5 g/m2 I.V. days 1-5 every 3 weeks. This regimen was chosen because of the activity of doxorubicin and nitrosoureas in hepatocellular carcinoma and the ability to administer both drugs in full doses. Twelve patients were fully ambulatory, 14 had normal serum bilirubin, 11 had pathologic proof of cirrhosis, and 11 had no known extrahepatic tumor dissemination. Partial responses lasting 10 and 14 months occurred in two patients (9%), one had stable disease for 15 months, 12 had documented tumor progression within 4 months, and eight died within 6 weeks of the start of chemotherapy. Median survival of all patients was only 3 months (range 0.3-27), but eight (35%) lived more than 1 year. Of these eight, two responded to doxorubicin and streptozotocin, another two to subsequent chemotherapy, and four had no tumor response whatever. More than 90% of the intended doses of doxorubicin and streptozotocin was administered, with severe leukopenia in three patients, moderate thrombocytopenia in one, and moderate proteinuria in nine. There were no drug-related deaths. Various physical, radiologic, and biochemical parameters were employed in detecting tumor response and progression. Initially abnormal physical examination of the liver, hepatic radionuclide and computed tomographic (CT) scans, and serum alpha-fetoprotein levels improved in both responding patients. Tumor progression was detected by physical examination (7/12), radionuclide (10/12) and CT liver scan (3/7), rising alpha-fetoprotein (5/12), and rising carcinoembryonic antigen (3/8). Physical examination and radionuclide liver scan together documented all tumor response and progression. The combination of doxorubicin and streptozotocin has only modest activity in hepatocellular carcinoma and appears no more active than doxorubicin alone.

Comparative value of bone scintigraphy and radiography in monitoring tumor response in systemically treated prostatic carcinoma.

Radionuclide bone scans and skeletal radiographs were obtained before and during combination chemotherapy or initial hormonal treatment in 46 patients with disseminated adenocarcinoma of the prostate. The purpose of the study was to determine the usefulness of these two modalities in evaluating tumor response to therapy. Prior to treatment, bone scans were positive in 44 patients (96%). In all but one patient either bone radiographs or bone marrow biopsy revealed evidence of osseous metastases. In 22 patients partial response to therapy was documented by a variety of other staging tests. Eleven of these patients showed concurrent or later improvement on bone scans; one showed improvement on a radiograph. "Flare phenomena" were observed relatively frequently since 23% of the scans and 50% of the radiographs showed worsening at the time of response. Bone scans revealed worsening in 79% of 33 patients with disease progression of extraosseous tumor; radiographs were equally sensitive (82% worsening). It is concluded that bone scans in particular are useful for monitoring tumor status in systemically treated patients with prostate cancer. However, because of the lack of sensitivity for response and paradoxical worsening with tumor regression in some patients, scans are not accurate enough to be employed as the sole test in following these patients.

Evaluation of weekly escalating doses of dichloromethotrexate in patients with hepatocellular carcinoma and other solid tumors.

Twenty-one patients with solid tumors were treated with weekly 6-h intravenous infusions of dichloromethotrexate (DCM), with escalating doses every other week. Frequently observed toxicities included leukopenia, thrombocytopenia, and mucositis. Nausea, vomiting, diarrhea, and elevation of hepatic enzymes and bilirubin occurred less often. The toxicity of DCM was dose-dependent; the maximum tolerated dosage excalation plan was 400 mg/m2 x 2 weeks, 800 mg/m2 x 2 weeks, and then 1,200 mg/m2 weekly. Plasma concentrations of DCM were measured during 61 infusions and apparent half-lives determined. The plasma elimination of DCM appears to be similar to that of methotrexate. Three objective tumor responses seen in the seven hepatocellular carcinoma patients treated warrant further investigation.

Septicemic complications of the cutaneous T-cell lymphomas.

The records of 60 consecutive patients with cutaneous T-cell lymphomas were reviewed to determine the incidence, etiology, predisposing factors, therapy, complications and outcome of septicemia. Fourteen (23 percent) patients had 26 septicemias: due to gram-positive cocci in 21 and to gram-negative bacilli in five. The presence of stage IV lymphomatous disease (p 0.032), generalized erythroderma (p less than 0.001), palpable lymph nodes (p 0.014), and histologic involvement of lymph nodes (p 0.023) and peripheral blood (p less than 0.001) identified a subset of patients at high risk for sepsis. Sepsis was correlated with locally infected sites in 77 percent of the episodes. Single antimicrobial therapy was successful in all septicemias due to gram-positive cocci but was accompanied by five secondary gram-negative bacillary superinfections (80 percent fatal). The subsequent mortality in all patients who survived infection (50 percent) indicated their poor over-all prognosis.

Effective treatment of hormonally-unresponsive metastatic carcinoma of the prostate with adriamycin and cyclophosphamide: methods of documenting tumor response and progression.

Combination chemotherapy with Adriamycin and cyclophosphamide was administered to 22 men with progressive tumor following hormonal treatment for metastatic carcinoma of the prostate. Objective partial response was documented in 7 patients (32%); an additional four (18%) had stable disease for a minimum of four months, and 11 (50%) were non-responders. Patients with partial response had a median survival of 14 months and lived significantly longer than those with no response (median five months); survival of men with stable disease approximated that of partial responders. Serial utilization of multiple staging procedures during chemotherapy demonstrated that although no single test allowed identification of all patients with objective tumor response or progression, improvement in median of five parameters could be documented in responding patients. In patients adequately studied at the time of disease progression, deterioration in a median of six tests was found. Serum acid phosphatase radionuclide bone scan, and plasma carcinoembryonic antigen were the most sensitive procedures which detected both objective tumor response and progression. Toxicity of chemotherapy was acceptable except in patients with prior radiation therapy. Administration of Adriamycin and cyclophosphamide was associated with clinical benefit in half of our patients with hormone-resistant prostatic cancer. Tumor response and progression can best be objectively assessed if several staging procedures are serially employed during treatment.

5-fluorouracil, methyl-CCNU, adriamycin, and mitomycin C in the treatment of advanced gastric cancer.

Eighteen previously untreated patients with advanced nonresectable adenocarcinoma of the stomach were treated with a four-drug regimen consisting of 5-fluorouracil, methyl-CCNU, adriamycin, and mitomycin C. Objective responses occurred in only two patients (11%); the majority of patients had stable disease for greater than or equal to 8 weeks (61%). The median survival of 27 weeks was similar to that reported in other combination chemotherapy trials. Numerous staging and restaging procedures and strict response criteria were utilized and each was evaluated for its effectiveness in following responses. None of these parameters was useful for evaluating response of intra-abdominal tumor. We conclude that this four-drug combination is no better than previously described two-drug regimens.