Clinical predictors and microbiology of ventilator-associated pneumonia in the intensive care unit: a retrospective analysis in six Italian hospitals.

The purpose of this study was to assess the main clinical predictors and microbiological features of ventilator-associated pneumonia (VAP) in the Intensive Care Unit (ICU) environment. This work is a retrospective analysis over one year from September 2010 to September 2011. Patients' risk factors, causes of admission, comorbidities and respiratory specimens collected in six Italian ICUs were reviewed. Incidence and case fatality rate of VAP were evaluated. After stratification for VAP development, univariate and multivariate analyses were performed to assess the impact of patients' conditions on the onset of this infection. A total of 1,647 ICU patients (pts) were considered. Overall, 115 patients (6.9 %) experienced at least one episode of VAP. The incidence rate for VAP was 5.82/1,000 pts-days, with a case fatality rate of 44.3 %. Multivariate analysis showed that admission for neurological disorders (aIRR 4.12, CI 1.24-13.68, p = 0.02) and emergency referral to ICU from other hospitals (aIRR 2.11, CI 1.03-4.31, p = 0.04) were associated with higher risk of VAP, whereas a tendency to a higher risk of infection was detected for admission due to respiratory disease, cardiac disease, trauma and for having obesity or renal failure. A total of 372 microbiological isolates from respiratory specimens were collected in VAP patients. The most common species were Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, showing high resistance rates to carbapenems. Neurological disorders and emergency referral at the admission into the ICU are significantly associated with the onset of VAP. A high incidence of multi-drug resistant Gram- species was detected in the respiratory specimens.

Phase II study of NGR-hTNF in combination with doxorubicin in relapsed ovarian cancer patients.

BACKGROUND: The NGR-hTNF (asparagine-glycine-arginine-human tumour necrosis factor) is able to promote antitumour immune responses and to improve the intratumoural doxorubicin uptake by selectively damaging tumour blood vessels. METHODS: Patients progressing after ≥ 1 platinum/taxane-based regimen received NGR-hTNF 0.8 µg m(-2) and doxorubicin 60 mg m(-2) every 3 weeks. Primary endpoint was a Response Evaluation Criteria in Solid Tumors-defined response rate with a target of more than 6 out of 37 responding patients. RESULTS: A total of 37 patients with platinum-free interval lower than 6 months (PFI<6; n=25), or between 6 and 12 months (PFI=6-12; n=12) were enrolled. Median baseline peripheral blood lymphocyte count (PBLC) was 1.6 per ml (interquartile range, 1.2-2.1). In all, 18 patients (49%) received more than 6 cycles. Febrile neutropaenia was registered in one patient (3%). Among 35 assessable patients, 8 (23%; 95% CI 12-39%) had partial response (2 with PFI<6; 6 with PFI=6-12) and 15 (43%) had stable disease (10 with PFI<6; 5 with PFI=6-12). Median progression-free survival (PFS) was 5.0 months for all patients, 3.8 months for patients with PFI<6, and 7.8 months for patients with PFI=6-12. Median overall survival (OS) was 17.0 months. Patients with baseline PBLC higher than the first quartile had improved PFS (P=0.01) and OS (P=0.001). CONCLUSION: Tolerability and activity of this combination warrant further randomised testing in patients with PFI<6. The role of PBLC as a blood-based biomarker deserves further investigation.

Activity and safety of NGR-hTNF, a selective vascular-targeting agent, in previously treated patients with advanced hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly vascularised and poor-prognosis tumour. NGR-hTNF is a vascular-targeting agent consisting of human tumour necrosis factor-alpha fused to the tumour-homing peptide NGR, which is able to selectively bind an aminopeptidase N overexpressed on tumour blood vessels. METHODS: Twenty-seven patients with advanced-stage disease resistant to either locoregional (59%; range, 1-3), systemic treatments (52%; range, 1-3) or both (33%) received NGR-hTNF 0.8 microg m(-2) once every 3 weeks. The primary aim of the study was progression-free survival (PFS). RESULTS: No grade 3-4 treatment-related toxicities were noted. Common toxicity included mild-to-moderate, short-lived chills (63%). Median PFS was 2.3 months (95% CI: 1.7-2.9). A complete response ongoing after 20 months was observed in a sorafenib-refractory patient and a partial response in a Child-Pugh class-B patient, yielding a response rate of 7%. Six patients (22%) experienced stable disease. The disease control rate (DCR) was 30% and was maintained for a median PFS time of 4.3 months. Median survival was 8.9 months (95% CI: 7.5-10.2). In a subset of 12 sorafenib-resistant patients, the response rate was 8% and the median survival was 9.5 months. CONCLUSION: NGR-hTNF was well tolerated and showed single-agent activity in HCC. Further investigation in HCC is of interest.

Phase Ib study of NGR-hTNF, a selective vascular targeting agent, administered at low doses in combination with doxorubicin to patients with advanced solid tumours.

BACKGROUND: Asparagine-glycine-arginine-human tumour necrosis factor (NGR-hTNF) is a vascular targeting agent exploiting a tumour-homing peptide (NGR) that selectively binds to aminopeptidase N/CD13, overexpressed on tumour blood vessels. Significant preclinical synergy was shown between low doses of NGR-TNF and doxorubicin. METHODS: The primary aim of this phase I trial was to verify the safety of low-dose NGR-hTNF combined with doxorubicin in treating refractory/resistant solid tumours. Secondary objectives included pharmacokinetics (PKs), pharmacodynamics, and clinical activity. In all 15 patients received NGR-hTNF (0.2-0.4-0.8-1.6 microg m(-2)) and doxorubicin (60-75 mg m(-2)), both given intravenously every 3 weeks. RESULTS: No dose-limiting toxicity occurred and the combination was well tolerated. Around two cases of neutropenic fevers, lasting 2 days, and two cases of cardiac ejection-fraction drops, one asymptomatic and the other symptomatic, were registered. Only 11% of the adverse events were related to NGR-hTNF and were short-lasting and mild-to-moderate in severity. There was no apparent PK interaction and the shedding of soluble TNF-receptors did not increase to 0.8 microg m(-2). One partial response (7%), at dose level 0.8 microg m(-2), and 10 stable diseases (66%), lasting for a median duration of 5.6 months, were observed. CONCLUSIONS: NGR-hTNF plus doxorubicin was administered safely and showed promising activity in patients pre-treated with anthracyclines. The dose level of 0.8 microg m(-2) NGR-hTNF plus doxorubicin 75 mg m(-2) was selected for phase II development.

Cytokine secretion associated with the clearance of apoptotic bodies in renal cell carcinoma patients.

The factors determining the outcome of immunotherapy in metastatic renal cell carcinoma (RCC) patients remain elusive. Macrophages from normal donors that phagocytose apoptotic cells secrete the immunosuppressive cytokine IL-10 in vitro. Conversely, IL-10 genetic deletion enhances the immunogenicity of apoptotic tumor cells in vivo. Elevated pre-treatment levels of IL-10 are associated with an unfavorable outcome of RCC. We examined whether the ability to release IL-10 by macrophages from RCC patients that phagocytosed apoptotic cells correlated with the outcome of immunotherapy. To this aim, we derived macrophages from 30 patients with metastatic RCC and from 21 healthy subjects (11 sex- and age-matched healthy controls and 10 younger donors). Patients either had a clinical response after immunotherapy, with a median survival after treatment of more than 18 months (n = 16), or were beginning immunotherapy after diagnosis of metastatic disease (n = 14). Macrophages from responding patients challenged with apoptotic cells released significantly less IL-10 than controls (p = 0.0075) and recently diagnosed patients (p = 0.0198), as ascertained by a 2-sided Student's t-test. This was not because macrophages from responding patients lost the ability to secrete IL-10, because antibody opsonization of apoptotic cells rescued IL-10 secretion. In contrast, macrophages from all groups of donors released similar amounts of TNF-alpha. The failure in IL-10 secretion by engulfing macrophages of responding subjects may exalt the immunogenicity of dying tumor cells, contributing to the success of immunotherapy.

In vivo administration of GM-CSF promotes the clearance of apoptotic cells: effects on monocytes and polymorphonuclear leukocytes.

The clearance of apoptotic cells is crucial to avoid chronic inflammation and autoimmunity. Little is known about the factors that regulate it in vivo. We show that granulocyte-macrophage colony-stimulating factor (GM-CSF) administration to carcinoma patients confers to their leukocytes a significantly higher ability to phagocytose apoptotic cells than before (P < 0.005). GM-CSF increased the concentration of monocytes and polymorphonuclear leukocytes in the peripheral blood and activated circulating polymorphonuclear leukocytes. Both effects abated early after treatment, whereas phagocytosis of apoptotic cells was still significantly higher after 18 days compared with basal values (P < 0.005 and P < 0.025 for monocytes and polymorphonuclear leukocytes, respectively). On in vitro phagocytosis of apoptotic cells monocytes, but not polymorphonuclear leukocytes, up-regulated MHC class II membrane expression. These findings are consistent with the possibility that GM-CSF endows both scavenger and antigen-presenting leukocytes with the ability to internalize apoptotic tumor cells.

Interleukin-2, interferon-alpha and interleukin-2 plus interferon-alpha in renal cell carcinoma. A randomized phase II trial.

BACKGROUND: The purpose of the present study was to investigate the therapeutic effectiveness of interleukin-2 (IL-2) and interferon (IFN), either alone or in combination, in comparable groups of patients affected by advanced renal cell carcinoma (RCC). PATIENTS AND METHODS: In order to limit selection biases, treatment was allocated on a random basis. Patients randomized to IL-2 alone were scheduled to receive eight rlL-2 24-hour i.v. infusion cycles, days 1 to 4, at a daily dose of 18 x 10(6) lU/m2 for a total of 25 weeks. Patients randomized to IFN alone were scheduled to receive rIFN-alpha at a daily dose of 6 x 10(6) IU/m2, days 1, 3 and 5, every week for a total of 52 weeks. Patients randomized to the combination of IFN and IL-2 were given the same drugs at the same daily doses for a total of 24 weeks. Drug dose was modified according to toxicity. RESULTS: Twenty-three percent (95% CI:+/-17.5) of patients treated with IL-2 alone showed an objective response to treatment (9% CR). The corresponding figures in patients treated with IFN alone or IFN plus IL-2 were 9% (95% CI:+/-11.9) and 9% (95% CI:+/-11.9), respectively. Complete responses were observed only in patients treated with IL-2. The median duration of response in the IL-2 arm was 18 months (range, 9.5-24). The duration of the two responses achieved by IFN alone was seven and nine months, respectively. The corresponding figures in the two patients responding to the combination of IFN with IL-2 were 19 and 27 months, respectively. Total IL-2 dose appeared to be a major predictor of response. Only a minority of patients experienced grade 3-4 toxicity, the incidence being higher in those treated with IL-2 or IL-2 plus IFN. CONCLUSIONS: Neither IFN nor IL-2 or the combination of the two appear to be very active in patients with advanced RCC, even when trial entry was restricted to patients with relatively indolent disease. This stresses the need for the development of new approaches.

Prognostic factors for survival in metastatic renal cell carcinoma: retrospective analysis from 109 consecutive patients.

OBJECTIVE: Metastatic renal cell cancer (RCC) portends a bad prognosis, but survival is quite different among different patients. The objective of this study was to determine prognostic factors for survival with the aim to offer patients proper therapeutic options. METHODS: A consecutive series of 109 metastatic RCC patients admitted to our department since 1988 was reviewed, and survival from the time of diagnosis with metastases recognition was considered. The role of age, sex, disease-free interval (DFI), ECOG performance status (PS), stage at diagnosis, grading, number and type of metastatic sites, nephrectomy, blood levels of hemoglobin, creatinine, albumin, calcium, lactate dehydrogenase (LDH), ferritin, alkaline phosphatase, triglycerides was assessed in univariate and multivariate analysis. RESULTS: In our study, the following variables were found to be statistically significant at the univariate analysis (p < 0.01): DFI, ECOG PS, stage at diagnosis, grading, nephrectomy, sites of metastases, blood hemoglobin, serum albumin, calcium, LDH, alkaline phosphatase. Indeed, only an ECOG PS of 2-3 (relative risk 1.82; p = 0.003) and blood hemoglobin levels < or = 10 g/100 ml (relative risk 1.20; p = 0.017) retained their value as independent risk factors for poor survival at multivariate analysis. According to the number of independent risk factors, three groups of patients were identified, with significantly different median survival (21.7 vs. 8.6 vs. 3.5 months; log-rank test: p = 0.00004, p = 0.04126 and p = 0.00047, respectively). CONCLUSIONS: Poor performance status and anemia at diagnosis of metastatic RCC predict the worst outcome in our series. These factors could be taken into account to stratify patients in clinical trails and to select the proper treatment option in oncological practice.

Plasma nitrate plus nitrite changes during continuous intravenous infusion interleukin 2.

Nitric oxide (NO), a biologically active mediator generated in many cell types by the enzyme NO synthase, may play an important role in cardiovascular toxicity that is frequently observed in cancer patients during intravenous (i.v.) interleukin 2 (IL-2) therapy. The induction of NO synthase and the production of NO seem to be involved in the pathogenesis of the vascular leakage syndrome, as well as in the regulation of myocardial contractility. In the present study, we evaluated the pattern of plasmatic NO changes during multiple cycles of continuous i.v. infusion (CIVI) of IL-2 in ten advanced cancer patients (five males, five females, median age 59 years, range 33-67 years; eight affected by renal cell cancer and two affected by malignant melanoma). The patients received IL-2 at 18 MIU m-2 day-1 (14 cycles) or 9 MIU m-2 day-1 (seven cycles) for 96 h, repeated every 3 weeks. Interferon alpha (IFN alpha) was also administered subcutaneously (s.c) during the 3 week interval between IL-2 cycles. For each cycle, plasma samples were collected before treatment (t0), 24 h (t1), 48 h (t2), 72 h (t3) and 96 h (t4) after the start of IL-2 infusion, and 24 h after the end of the cycle. NO concentration was determined spectrophotometrically by measuring the accumulation of both nitrite and nitrate (after reduction to nitrite). The following observations may be drawn from data analysis: (1) plasma nitrate + nitrite significantly raised during treatment (P = 0.0226 for t0 vs t3), but statistical significance was retained only when cycles administered with IL-2 18 MIU m-2 day-1 are considered (P = 0.0329 for t0 vs t3; P = 0.0354 for t0 vs t2 vs t4) (dose-dependent pattern); (2) during subsequent cycles a significant trend toward a progressive increase of plasma nitrate + nitrite levels, with increasing cumulative dose of IL-2, was observed (linear regression coefficient r = 0.62, P = 0.0141 for t0; r = 0.80, P = 0.0003 for t1; r = 0.62, P = 0.013 for t2; r = 0.69, P = 0.045 for t3); (3) plasma nitrate + nitrite levels peaked earlier in subsequent cycles than in the first cycle; (4) all patients experienced hypotension. The mean of the systolic blood pressure values was significantly lower at the time of plasma nitrate + nitrite peak than at t0 (P = 0.0004); (5) the two cases of grade III hypotension occurred in patients with the higher mean and peak plasma nitrate + nitrite values. We conclude that determination of plasma nitrate + nitrite levels during CIVI IL-2 can usefully estimate, in a dose-dependent pattern, the degree of peripheral vascular relaxation and capillary leakage associated with cytokine action, clinically manifested as hypotension. However, isolated cardiac toxicity that continues to represent a relevant problem during IL-2 therapy, does not appear to correlate with plasma nitrate + nitrite levels; therefore, further studies are required to understand adequately the mechanisms underlying IL-2-induced cardiac toxicity.

Increased interleukin-10 serum levels in patients with solid tumours.

In 40 out of 99 patients (40.4%) with solid tumours of different tissue, but the same stage (IV), elevated serum levels of interleukin-10 were observed. The mean levels of the cytokine in patients with malignant melanoma (24.3 ng/ml), pancreatic (6.8 ng/ml) or gastric (6.3 ng/ml) adenocarcinoma were significantly higher than in healthy subjects (3.4 ng/ml) or in patients with uterine fibroma (1.7 ng/ml). Patients with colon (6.8 ng/ml) and renal (5.7 ng/ml) carcinoma had similar values of interleukin-10 but did not significantly differ from controls. Interleukin-10 is known to suppress the functions of both T lymphocytes and macrophages, working as a general dampener of the immune and inflammatory responses. The observation of increased circulating levels of interleukin-10 in cancer patients may have important implications for future investigations, immunological monitoring and therapeutic intervention on neoplastic patients, and suggests a mechanism for tumour cells escaping from immune surveillance.

Isolated left ventricular filling abnormalities may predict interleukin-2-induced cardiovascular toxicity.

Interleukin-2 (IL-2) is a cytokine with proven activity against metastatic renal cell carcinoma (RCC) and malignant melanoma (MM). The intravenous administration of high-dose IL-2 is limited by important cardiovascular side effects such as hypotension, fluid retention, arrhythmias, and myocardial ischemia, which often cause dose reduction and/or treatment withdrawal. The occurrence of these toxic events is not predicted by routine pretreatment examinations. The aim of the present study was to test the reliability of serial echocardiography in predicting subsequent cardiac adverse effects in patients undergoing IL-2 administration. In 19 patients (15 men, 4 women; median age: 51 years, range 27-71 years; 10 affected by metastatic RCC and 9 affected by MM) we performed two-dimensional and Doppler echocardiography before and immediately after 28 continuous intravenous infusions (CIVI) of IL-2 at the dose of 18 MIU/m2/day for 4 days. Left ventricular systolic function and the diastolic transmitral flow pattern were assessed before and after IL-2 administration. Significant changes of two indexes of left ventricular filling were noted: a decrease of the ratio of maximal flow velocity in early diastole to that in late diastole (E/A) (basal: 1.12 +/- 0.46, mean +/- SD; posttreatment: 0.83 +/- 0.27; p < 0.01) and an increase of the percentage of the atrial contribution to left ventricular filling (basal: 37.75 +/- 11.58%; posttreatment: 49.43 +/- 16.48%; p < 0.01). Eight major cardiovascular events causing IL-2 infusion withdrawal were observed (two ischemic electrocardiographic modifications, three grade III-IV hypotension, one atrial fibrillation, one pericardial effusion, one acute heart failure). These major cardiovascular events were observed more often when an abnormal basal E/A ratio < 1.0 (p < 0.05) was found. We conclude that Doppler transmitral flow pattern analysis before and subsequent to IL-2 infusion is a useful and easily available procedure for the monitoring of cardiac modifications during CIVI IL-2 administration. It might also predict a major cardiovascular event during IL-2 administration. Patients with basal E/A ratio < 1.0 should be more carefully monitored during treatment and/or should be treated with lower IL-2 doses to avoid cardiovascular toxicity.

Serum levels of soluble cell adhesion molecules (ICAM-1, VCAM-1, E-selectin) and of cytokine TNF-alpha increase during interleukin-2 therapy.

Circulating levels of soluble intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin were measured in 20 advanced cancer patients at different times during recombinant interleukin-2 immunotherapy. The concentration of all three molecules progressively increased as did the levels of circulating tumor necrosis factor-alpha (TNF-alpha), which is known to induce endothelial cell activation. A fair direct relationship (but not statistically significant) between the raised concentration of soluble cell adhesion molecules and TNF-alpha was observed. We suggest that elevated levels of soluble adhesion molecules and TNF-alpha in the blood of IL-2-treated patients may arise from a systemic inflammatory reaction producing endothelial cell activation.

The feasibility of repetitive courses of high-dose continuous intravenous infusion interleukin-2 and subcutaneous alpha-interferon with polychemotherapy in advanced malignant melanoma.

AIMS AND BACKGROUND: A Phase I study of repetitive courses of chemotherapy (carmustine, cis-platinum, dacarbazine) and immunotherapy (continuous intravenous infusion recombinant interleukin-2 (rIL-2) and subcutaneous (sc) alpha-interferon 2b) plus tamoxifen was performed in order to establish a more efficacious way to sequence this kind of treatment for advanced malignant melanoma. STUDY DESIGN: Patients who had measurable metastatic melanoma, a Karnofsky performance status > or = 80, and no clinically significant hematologic or cardiac disfunction were considered eligible. Treatment consisted of BCNU, 150 mg/m2 i.v. day 1 in alternating cycles; DTIC, 220 mg/m2 i.v. days 1, 2 and 3; CDDP, 25 mg/m2 i.v. days 1, 2 and 3; tamoxifen 10 mg twice/day per os continuously; rIL-2, 18 x 10(6) IU/m2/day continuous i.v. infusion days 5-8 (96 h) and days 19-22 (96 h); alpha-interferon (IFN) s.c. 3 x 10(6) U day 12, 6 x 10(6) U day 14, 9 x 10(6) U days 16, 19, 21, 23, 26, and 28 (from cycle 2, 9 x 10(6) U days 2, 5, 7, 9, 12, 14, 16, 19, 21, 23, 26, and 28). Two consecutive cycles were planned until response evaluation. RESULTS: Three patients were treated according with the protocol; none of them was able to respect the planned dose-intensity schedule. The given dose intensity/planned dose intensity ratios were as follows: DTIC, 0.74 (range, 0.70-0.80); CDDP, 0.77 (0.72-0.80); BCNU, 0.77 (0.72-0.80); rIL-2, 0.65 (0.36-0.80); alpha-IFN, 0.01 (0-0.03); tamoxifen, 1.0. Systemic side effects of rIL-2 and myelotoxicity were the main reasons for treatment delay and/or dose-reduction, and for the long period of hospital care. CONCLUSIONS: We conclude that the treatment schedule is not feasible. However, since we believe that combined chemo-immunotherapy is a potentially active treatment in metastatic malignant melanoma, we have modified it in order to make it more feasible and consequently efficacious.

Reversible anergy in circulating lymphocytes of cancer patients during interleukin-2 therapy.

Interleukin-2 plays a crucial role in enhancing the antitumor immune response. Clinical trials, mainly in renal cell carcinoma and melanoma patients, have been carried out with encouraging results. Recent reports demonstrated that interleukin-2 therapy may depress the immune response either in vitro or in vivo. We decided to monitor, in nine renal cancer patients, the proliferative responses and the parallel variations in Ca2+ homeostasis of peripheral blood lymphocytes collected before, during and after the first cycle of a 3-day interleukin-2 systemic administration. The proliferative response to phytohemagglutinin or concanavalin A significantly dropped early during interleukin-2 infusion. Consistently, an impairment in mobilizing Ca2+, either from internal stores or via influx from outside, was observed. Results obtained with a mAb-alpha CD3 molecular complex strongly suggested that the TCR/CD3 signal transduction pathway was defective. In contrast, no major variations were observed in the general machinery controlling Ca2+ homeostasis nor in the total Ca(2+)-releasable pool. Patients' lymphocytes, cultured in vitro for 3 days in medium alone, showed an almost complete recovery in their ability to respond to mitogens. In conclusion, we show that interleukin-2 administration in cancer patients induces a reversible state of anergy in circulating lymphocytes, assessed both by the reduction in the proliferative response and the block of the mitogen-activated intracellular Ca2+ signalling.

Intrapleural administration of interleukin-2 and LAK cells in locally advanced non-small-cell lung cancer. A case report.

AIMS AND BACKGROUND: The systemic administration of recombinant interleukin-2 (rIL-2) and lymphokine-activated killer (LAK) cells is ineffective in non-small-cell lung cancer (NSCLC). However, there is some evidence that their intrapleural administration could be effective, since it increases the concentrations of the cytokine and the effector cells in the tumor area, thereby obtaining greater antitumor activity. STUDY DESIGN: We report the case of a patient affected by a locally advanced lung adenocarcinoma with pleural effusion (T4 N0 M0-stage IIIb) treated with repetitive courses consisting of a priming continuous i.v. infusion (48 h) of rIL-2 (18 MIU/m2/day) intraplural administration of LAK cells (3-9 x 10(9)/day), in a single daily bolus, for 3 consecutive days and concomitant administration of rIL-2 (1.8-7.2 x 10(6) IU/day), for 5 days. RESULTS: We observed early disappearance of neoplastic cells in the pleural effusion, progressive decrease until disappearance of the pleural effusion, cavitation of the primary lesion during the treatment, and its stabilization for 9 months until progression. Radiologic changes were accompanied by a marked eosinophilia (up to 50 x 10(9)/L), and the intrapleural route of administration of rIL-2 induced a relevant increase in eosinophil count in peripheral blood. Immunologic changes in lymphocyte subpopulation phenotypes were also observed. The performance status of the patient improved, and she was still alive and eupnoic 25 months from the diagnosis and 23 months from the start of treatment. CONCLUSIONS: This case suggests a therapeutic role for intrapleural rIL-2, and we believe that the relationship among intrapleural administration of rIL-2 and LAK cells, the development of peripheral eosinophilia, and clinical response should be further investigated.

Treatment of advanced renal cell cancer with sequential intravenous recombinant interleukin-2 and subcutaneous alpha-interferon.

Starting from in vitro studies suggesting synergistic antitumour activity against renal cell cancer (RCC) of recombinant interleukin-2 (rIL-2) and alpha-interferon (IFN), a phase II trial was initiated to test the clinical activity of this combination. The two cytokines were administered sequentially, with the aim of reducing the risk of additive toxicity and enhancing the immunological reaction against the tumour. The original treatment schedule consisted of rIL-2 18 x 10(6) U/m2/day by continuous intravenous infusion for 120 h days 1-5, and alpha-IFN 2b, at a flat dose of 9 x 10(6) U by subcutaneous or intramuscular injection thrice in a week, from day 8 to 28. Treatment was planned to be continued for six or more 28-day cycles, depending on clinical response. 12 patients were treated according to this schedule; as some cardiovascular toxicity was experienced in this set of patients, 11 further patients were treated with half-dose rIL-2 (i.e. 9 x 10(6) U/m2/day). 17 out of 23 enrolled patients completed at least one cycle of treatment and were evaluated for response. We observed six major responses [one complete response (CR) + five partial responses (PR)] for an objective response rate of 35% [95% confidence interval (CI) 17-59%]. 5 additional patients achieved stabilisation of disease; one of them reached CR after surgical extirpation of a lung mass. Sites of response included lung, nodes and bone. Duration of response is 12+ months for CR; 17, 16, 12+, 9 and 9 months for PRs. Median survival is 16 months. Response was not significantly different between full-dose and half-dose rIL-2. Considering stable disease (SD) as responses, there seemed to be a higher chance of response for patients with smaller tumour burden (P = 0.032). The toxicity of rIL-2 treatment, mainly cardiovascular, was substantial; 9 patients experienced severe cardiotoxicity, consisting of major arrhythmias, myocardial ischaemia, reduction of ejection fraction measured with heart radionuclide scan, and were excluded from continuing treatment. Other rIL-2-related toxicities forcing exclusion from the study were severe thrombocytopenia (1 case), and generalised exfoliative dermatitis requiring steroids (1 case). Otherwise, treatment was well tolerated; rIL-2-related toxicities promptly recovered after rIL-2 discontinuation in the majority of cases, and no treatment-related deaths were reported. The half-dose rIL-2 regimen was significantly less toxic in terms of hypotension (P = 0.014), fever (P = 0.014), oliguria (P = 0.042), serum creatinine elevation (P = 0.009) and prothrombin time elongation (P = 0.038).(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of stretch receptors of bronchi or trachea on genioglossus muscle activity.

Activity of genioglossus muscle (GG) was recorded in anesthetized rabbits at control and under SO2 block of slowly adapting stretch receptors in thoracic airways (T) or in bronchi alone (B). At control peak activity occurred at 10% of inspiratory time, followed by a slight and a marked decrease. T and, particularly, B delayed onset and slowed rise of GG activity; then, this increased slightly under T and more under B, becoming greater than at control. During inspiratory efforts at end-expiratory volume GG activity at control was equal to that during open inspirations up to its peak, then progressively greater; during inspiratory efforts GG activity under T and B was equally smaller than at control. These findings indicate that bronchial input facilitates GG activity at end-expiratory volume and inhibits it at larger volumes: these effects are greater than those previously detected on diaphragm. Moreover, tracheal input inhibits onset and development of GG activity. Under all conditions end of inspiratory activity was simultaneous in GG and in diaphragm. Time to peak inspiratory flow correlated with time to early peak in GG activity.

Mechanical transients initiated by ramp stretch and release to Po in frog muscle fibers.

Single fibers from the tibialis muscle of Rana temporaria were subjected to ramp stretches during tetanic stimulation at a sarcomere length of approximately 2 microns. Immediately after the stretch, or after different time delays, the active fiber was released against a constant force equal to the isometric force (Po) exerted immediately before the stretch. Four phases were detected after release: an elastic recoil of the fiber's undamped elements, a transient rapid shortening, a marked reduction in the velocity of shortening (often to 0), and an apparently steady shortening (sometimes absent). Increasing the amplitude of the stretch from approximately 2 to 10% of the fiber rest length led to an increase in phase 2 shortening from approximately 5 to 10 nm per half-sarcomere. Phase 2 shortening increased further (up to 14 nm per half-sarcomere) if a time interval of 5-10 ms was left between the end of large ramp stretches and release to Po. After 50- to 100-ms time intervals, shortening occurred in two steps of approximately 5 nm per half-sarcomere each. These findings suggest that phase 2 is due to charging, during and after the stretch, of a damped element, which can then shorten against Po in at least two steps of approximately 5 nm/half sarcomere each.

Discontinuity between inspiratory and postinspiratory diaphragm activity in man and rabbit.

Diaphragm activity (Edi, 20 Hz low cutoff) was recorded with great time resolution to ascertain whether there is a discontinuity between its inspiratory and postinspiratory periods in humans. We first determined in anesthetized rabbits that gaps or notches in Edi occurred within 80 msec before and after the end of mechanical inspiration in 70% of the analysable breaths in the esophageal lead and in 77% in direct leads. We then determined from the esophageal lead of 4 conscious subjects that gaps or notches in Edi occurred during the above-defined period in 45% of 682 analysable breaths. In each subject mean of moving average Edi (12 msec averaging interval) was computed out of 14-24 breaths, free of ECG artifacts within 200-250 msec before and after end inspiration. A deep indentation occurred near end-inspiration despite the lack of gaps or notches in 1/2 to 4/5 of these breaths. These results suggest that also in humans postinspiratory diaphragm activity does not represent the decay of inspiratory ramp.