A transcriptomics approach to expand therapeutic options and optimize clinical trials in oncology

Background

The current model of clinical drug development in oncology displays major limitations due to a high attrition rate in patient enrollment in early phase trials and a high failure rate of drugs in phase III studies.

Objective

Integrating transcriptomics for selection of patients has the potential to achieve enhanced speed and efficacy of precision oncology trials for any targeted therapies or immunotherapies.

Methods

Relative gene expression level in the metastasis and normal organ-matched tissues from the WINTHER database was used to estimate in silico the potential clinical benefit of specific treatments in a variety of metastatic solid tumors.

Results

As example, high mRNA expression in tumor tissue compared to analogous normal tissue of c-MET and its ligand HGF correlated in silico with shorter overall survival (OS; p < 0.0001) and may constitute an independent prognostic marker for outcome of patients with metastatic solid tumors, suggesting a strategy to identify patients most likely to benefit from MET-targeted treatments. The prognostic value of gene expression of several immune therapy targets (PD-L1, CTLA4, TIM3, TIGIT, LAG3, TLR4) was investigated in non-small-cell lung cancers and colorectal cancers (CRCs) and may be useful to optimize the development of their inhibitors, and opening new avenues such as use of anti-TLR4 in treatment of patients with metastatic CRC.

Conclusion

This in silico approach is expected to dramatically decrease the attrition of patient enrollment and to simultaneously increase the speed and detection of early signs of efficacy. The model may significantly contribute to lower toxicities. Altogether, our model aims to overcome the limits of current approaches.

Comorbidity between lung cancer and COVID-19 pneumonia: role of immunoregulatory gene transcripts in high ACE2-expressing normal lung

BACKGROUND

SARS-CoV-2 (COVID-19) elicits a T-cell antigen-mediated immune response of variable efficacy. To understand this variability, we explored transcriptomic expression of angiotensin-converting enzyme 2 (ACE2, the SARS-CoV-2 receptor) and of immunoregulatory genes in normal lung tissues from patients with non-small cell lung cancer (NSCLC).

METHODS

This study used the transcriptomic and the clinical data for NSCLC patients generated during the CHEMORES study [n = 123 primary resected (early-stage) NSCLC] and the WINTHER clinical trial (n = 32 metastatic NSCLC).

RESULTS

We identified patient subgroups with high and low ACE2 expression (p = 1.55 × 10^-19) in normal lung tissue, presumed to be at higher and lower risk, respectively, of developing severe COVID-19 should they become infected. ACE2 transcript expression in normal lung tissues (but not in tumor tissue) of patients with NSCLC was higher in individuals with more advanced disease. High-ACE2 expressors had significantly higher levels of CD8+ cytotoxic T lymphocytes and natural killer cells but with presumably impaired function by high Thymocyte Selection-Associated High Mobility Group Box Protein TOX (TOX) expression. In addition, immune checkpoint-related molecules - PD-L1, CTLA-4, PD-1, and TIGIT - are more highly expressed in normal (but not tumor) lung tissues; these molecules might dampen immune response to either viruses or cancer. Importantly, however, high inducible T-cell co-stimulator (ICOS), which can amplify immune and cytokine reactivity, significantly correlated with high ACE2 expression in univariable analysis of normal lung (but not lung tumor tissue).

CONCLUSIONS

We report a normal lung immune-tolerant state that may explain a potential comorbidity risk between two diseases - NSCLC and susceptibility to COVID-19 pneumonia. Further, a NSCLC patient subgroup has normal lung tissue expressing high ACE2 and high ICOS transcripts, the latter potentially promoting a hyperimmune response, and possibly leading to severe COVID-19 pulmonary compromise.

Transcriptomics in Tumor and Normal Lung Tissues Identify Patients With Early-Stage Non-Small-Cell Lung Cancer With High Risk of Postsurgery Recurrence Who May Benefit From Adjuvant Therapies

PURPOSE

The prognosis of patients with non-small-cell lung cancer (NSCLC), traditionally determined by anatomic histology and TNM staging, neglects the biological features of the tumor that may be important in determining patient outcome and guiding therapeutic interventions. Identifying patients with NSCLC at increased risk of recurrence after curative-intent surgery remains an important unmet need so that known effective adjuvant treatments can be offered to those at highest risk of recurrence.

METHODS

Relative gene expression level in the primary tumor and normal bronchial tissues was used to retrospectively assess their association with disease-free survival (DFS) in a cohort of 120 patients with NSCLC who underwent curative-intent surgery.

RESULTS

Low versus high Digital Display Precision Predictor (DDPP) score (a measure of relative gene expression) was significantly associated with shorter DFS (highest recurrence risk; P = .006) in all patients and in patients with TNM stages 1-2 (P = .00051; n = 83). For patients with stages 1-2 and low DDPP score (n = 29), adjuvant chemotherapy was associated with improved DFS (P = .0041). High co-overexpression of CTLA-4, PD-L1, and ICOS in normal lung (28 of 120 patients) was also significantly associated with decreased DFS (P = .0013), suggesting an immune tolerance to tumor neoantigens in some patients. Patients with DDPP low and immunotolerant normal tissue had the shortest DFS (P = 2.12E-11).

CONCLUSION

TNM stage, DDPP score, and immune competence status of normal lung are independent prognostic factors in multivariate analysis. Our findings open new avenues for prospective prognostic assessment and treatment assignment on the basis of transcriptomic profiling of tumor and normal lung tissue in patients with NSCLC.

A WIN Consortium phase I study exploring avelumab, palbociclib, and axitinib in advanced non-small cell lung cancer

Background

The Worldwide Innovative Network (WIN) Consortium has developed the Simplified Interventional Mapping System (SIMS) to better define the cancer molecular milieu based on genomics/transcriptomics from tumor and analogous normal tissue biopsies. SPRING is the first trial to assess a SIMS‐based tri‐therapy regimen in advanced non‐small cell lung cancer (NSCLC).

Methods

Patients with advanced NSCLC (no EGFR, ALK, or ROS1 alterations; PD‐L1 unrestricted; ≤2 prior therapy lines) received avelumab, axitinib, and palbociclib (3 + 3 dose escalation design).

Results

Fifteen patients were treated (five centers, four countries): six at each of dose levels 1 (DL1) and DL2; three at DL3. The most common ≥Grade 3 adverse events were neutropenia, hypertension, and fatigue. The recommended Phase II dose (RP2D) was DL1: avelumab 10 mg/kg IV q2weeks, axitinib 3 mg po bid, and palbociclib 75 mg po daily (7 days off/21 days on). Four patients (27%) achieved a partial response (PR) (progression‐free survival [PFS]: 14, 24, 25 and 144+ weeks), including two after progression on pembrolizumab. Four patients attained stable disease (SD) that lasted ≥24 weeks: 24, 27, 29, and 64 weeks. At DL1 (RP2D), four of six patients (66%) achieved stable disease (SD) ≥6 months/PR (2 each). Responders included patients with no detectable PD‐L1 expression and low tumor mutational burden.

Conclusions

Overall, eight of 15 patients (53%) achieved clinical benefit (SD ≥ 24 weeks/PR) on the avelumab, axitinib, and palbociclib combination. This triplet showed antitumor activity in NSCLC, including in tumors post‐pembrolizumab progression, and was active at the RP2D, which was well tolerated.

NCT03386929 clinicaltrial.gov

Digital Display Precision Predictor: the prototype of a global biomarker model to guide treatments with targeted therapy and predict progression-free survival

The expanding targeted therapy landscape requires combinatorial biomarkers for patient stratification and treatment selection. This requires simultaneous exploration of multiple genes of relevant networks to account for the complexity of mechanisms that govern drug sensitivity and predict clinical outcomes. We present the algorithm, Digital Display Precision Predictor (DDPP), aiming to identify transcriptomic predictors of treatment outcome. For example, 17 and 13 key genes were derived from the literature by their association with MTOR and angiogenesis pathways, respectively, and their expression in tumor versus normal tissues was associated with the progression-free survival (PFS) of patients treated with everolimus or axitinib (respectively) using DDPP. A specific eight-gene set best correlated with PFS in six patients treated with everolimus: AKT2, TSC1, FKB-12, TSC2, RPTOR, RHEB, PIK3CA, and PIK3CB (r = 0.99, p = 5.67E-05). A two-gene set best correlated with PFS in five patients treated with axitinib: KIT and KITLG (r = 0.99, p = 4.68E-04). Leave-one-out experiments demonstrated significant concordance between observed and DDPP-predicted PFS (r = 0.9, p = 0.015) for patients treated with everolimus. Notwithstanding the small cohort and pending further prospective validation, the prototype of DDPP offers the potential to transform patients' treatment selection with a tumor- and treatment-agnostic predictor of outcomes (duration of PFS).

SPRING: A Worldwide Innovative Network (WIN) Consortium phase I study of triple therapy (avelumab, axitinib, and palbociclib) in advanced non-small cell lung cancer (NSCLC) with genomic and transcriptomic correlates

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Background: The Worldwide Innovative Network (WIN) Consortium has developed the Simplified Interventional Mapping System (SIMS) algorithm in order to predict treatment response by comparing tumor and normal tissue biopsies on both genomic and transcriptomic platforms. SPRING is the first trial to assess a SIMS-based tri-therapy regimen in advanced non-small cell lung cancer (NSCLC). Methods: Patients with advanced NSCLC (no EGFR or ALK alterations; no ROS1 alterations if tested; PD-L1 unrestricted; ≤2 prior therapy lines) were treated with avelumab, axitinib, and palbociclib (3+3 dose escalation design). Tumor and normal endobronchial mucosal biopsies were obtained on all patients for retrospective SIMS algorithm validation. Results: Fifteen patients were treated: 6 at dose level 1 (DL1); 6, dose level 2 (DL2); 3, dose level 3 (DL3). Three dose-limiting toxicities (DLTs) at least possibly drug-related occurred: 1 DLT at DL2 (Grade 3 (G3) infusion reaction); 2 patients with DLTs at DL3 (1 with G3 hand/foot syndrome and G3 fatigue and 1 with G5 respiratory failure). Among 14 evaluable patients, the partial response (PR) rate was 28.6% (4/14 patients including 2/6 patients at DL1; two PRs in patients who failed prior pembrolizumab; two PRs in patients with PD-L1 < 1%). The maximum tolerated dose was avelumab 10 mg/kg IV q2weeks, axitinib 5 mg PO BID continuous, palbociclib 75 mg PO daily on days 8-28 of a 28 day cycle (DL2). DL2 was above the recommended phase II dose (RP2D), since 5/6 patients treated at DL2 required later treatment delays and/or dose reductions, mostly due to neutropenia. To further evaluate DL1, 3 patients were added to this cohort (total of 6). Since no DLTs were seen at DL1, and 5 of 6 patients did not require dose reduction, DL1 (avelumab 10 mg/kg IV q2weeks, axitinib 3 mg PO BID continuous, palbociclib 75 mg PO daily on days 8-28 of a 28 day cycle) is the RP2D. Conclusions: The RP2D was determined to be dose level 1. This triplet showed antitumor activity in patients with NSCLC, including those progressing on prior pembrolizumab. SIMS algorithm correlates of response are being assessed. Clinical trial information: NCT03386929 .

Abstract CT223: Survival Prolongation by Rationale INnovative Genomics (SPRING): An international WIN Consortium Phase I/II proof-of-concept study to explore the safety and efficacy of a tri-therapy approach using avelumab, palbociclib and axitinib in advanced/metastatic non-small cell lung cancer (NSCLC) with integrated genomic and transcriptomic correlates

Background: NSCLC is the leading cause of cancer death. Recently, much progress has been made to identify and target specific oncogenic drivers such as EGFR mutations and ALK translocations. Unfortunately, the majority of NSCLCs do not have a single driver, but instead harbor complex systems of molecular alterations. The advent of immunooncology has opened newer avenues for treating these patients, but still, many tumors are resistant. Therefore, selection of precise therapies targeting the appropriate pathways in these tumors is an important area of research. In previously published work, the Worldwide Innovative Network (WIN) Consortium has developed the Simplified Interventional Mapping System (SIMS) algorithm to match patients to a targeted drug triplet. The SIMS algorithm is based on the hypothesis that the use of both genomic as well as transcriptomic data is important in selecting an ideal tri-therapy regimen. Since the transcriptome varies widely between different types of normal tissue, the relative level of transcription of any given gene in a tumor must be normalized against the expected level of transcription of that gene in the analogous normal tissue. The SPRING trial is the first trial assessing a rational, SIMS-based tri-therapy regimen in advanced NSCLC. The drugs utilized for SPRING–avelumab (anti-PDL1), axitinib (VEGFR inhibitor) and palbociclib (CDK4/6 inhibitor)–were chosen because the SIMS genomic/transcriptomic analysis demonstrated that ~10% of NSCLCs have a combination of these targets.

Methods: Patients with locally advanced or metastatic NSCLC without EGFR or ALK alterations are being enrolled and treated with avelumab, palbociclib, and axitinib after informed consent. During phase I, any prior treatment is allowed. SPRING will assess the safety of the tri-therapy combination and determine the recommended phase II dose (RP2D) (3+3 dose escalation). Once the RP2D is found, the study will proceed directly to the phase II portion, which will permit only previously untreated patients in the metastatic setting. A biopsy of both tumor and normal tissue (by endobronchial mucosal biopsy) is obtained on all patients, both of which are analysed in a central genomics and transcriptomics platform. The SIMS algorithm is being validated retrospectively by determining the degree of genomic and transcriptomic matching and correlating with outcome.

Results: The phase I study is open in USA, Israel, Spain and Luxembourg and has enrolled 12 patients to date and has progressed to cohort 3. The phase II portion is expected to open later in 2019. This research is supported by the EMD Serono/Pfizer alliance and ARC Foundation for cancer research.

Citation Format: Benjamin Solomon, Enriqueta Felip, Jair Bar, Guy Berchem, Lyudmila Bazhenova, Pierre Saintigny, Nicolas Girard, Raed Sulaiman, Catherine Bresson, Fanny Wunder, J Jack Lee, Jacques Raynaud, Eitan Rubin, Brandon Young, Vladimir Lazar, Amir Onn, Brian Leyland Jones, Razelle Kurzrock. Survival Prolongation by Rationale INnovative Genomics (SPRING): An international WIN Consortium Phase I/II proof-of-concept study to explore the safety and efficacy of a tri-therapy approach using avelumab, palbociclib and axitinib in advanced/metastatic non-small cell lung cancer (NSCLC) with integrated genomic and transcriptomic correlates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT223.

Genomic and transcriptomic profiling expands precision cancer medicine: the WINTHER trial

Precision medicine focuses on DNA abnormalities, but not all tumors have tractable genomic alterations. The WINTHER trial ( NCT01856296 ) navigated patients to therapy on the basis of fresh biopsy-derived DNA sequencing (arm A; 236 gene panel) or RNA expression (arm B; comparing tumor to normal). The clinical management committee (investigators from five countries) recommended therapies, prioritizing genomic matches; physicians determined the therapy given. Matching scores were calculated post-hoc for each patient, according to drugs received: for DNA, the number of alterations matched divided by the total alteration number; for RNA, expression-matched drug ranks. Overall, 303 patients consented; 107 (35%; 69 in arm A and 38 in arm B) were evaluable for therapy. The median number of previous therapies was three. The most common diagnoses were colon, head and neck, and lung cancers. Among the 107 patients, the rate of stable disease ≥6 months and partial or complete response was 26.2% (arm A: 23.2%; arm B: 31.6% (P = 0.37)). The patient proportion with WINTHER versus previous therapy progression-free survival ratio of >1.5 was 22.4%, which did not meet the pre-specified primary end point. Fewer previous therapies, better performance status and higher matching score correlated with longer progression-free survival (all P < 0.05, multivariate). Our study shows that genomic and transcriptomic profiling are both useful for improving therapy recommendations and patient outcome, and expands personalized cancer treatment.

Natural and synthetic benzophenones: interaction with the cytosolic binding domain of P-glycoprotein

A benzophenone glycoside has been isolated from Davallia solida. Its structure was elucidated by chemical and spectral means as 4-O-beta-D-glucopyranosyl-2,6,4'-trihydroxybenzophenone. It bound with moderate affinity to the purified C-terminal cytosolic domain of P-glycoprotein, but the binding affinity was 6- to 10-fold increased for its aglycone derivative and other related benzophenones.

Modulation of cancer cell multidrug resistance by an extract of Ficus citrifolia

Multidrug resistance due to P-glycoprotein is a serious impediment to successful chemotherapy of cancer. Previous studies have shown that natural compounds such as prenyl flavonoids are able to modulate the multidrug resistance phenotype of P-glycoprotein-positive cancer cells. A fraction from the dichloromethane extract of a common Guadalupe Ficus, Ficus citrifolia was studied for its direct interaction with the purified C-terminal cytosolic domain of P-glycoprotein, and for its induced accumulation and cytotoxicity of vinblastine and daunomycin in two model cell lines overexpressing P-glycoprotein, namely K562/R7 and MESSA/Dx5. The fraction bound with high affinity to P-glycoprotein C-terminal cytosolic domain and was as efficient as cyclosporin A to increase intracellular accumulation of daunomycin in K562/R7 leukemic cells. Moreover, the fraction markedly enhanced the cytotoxic effect of vinblastine on the growth of MESSA/Dx5 cells. These results suggest that Ficus citrifolia possesses important therapeutic potential for improving the efficacy of cancer chemotherapy.

[Heparin-induced thrombopenia during hemodialysis in intensive care: use of a low molecular weight heparinoid, ORG 10172 (Orgaran)]

A 48-yr-old patient was admitted to the ICU for cardiogenic shock and acute renal failure after coronary artery bypass graft surgery. A heparin-induced thrombocytopenia (HIT) occurred during haemodialysis with unfractioned heparin (UFH) as the anticoagulant. The dialysers, the circuits and the catheters were recurrently thrombosing and the platelet count decreased to 9 G.L-1 on postoperative day 7. UFH was discontinued. Attempts to substitute UFH with a low molecular weight heparin (LMWH) failed, due to the presence of a high cross-reactivity rate of LMWH with the heparin-dependent antibody. Intermittent haemodialysis without anticoagulation using a predilution of the dialysers failed also and resulted in recurrent clotting. After informed consent of the patient, a new natural heparinoid Orgaran (Org 10172, Organon, Oss Holland) was administered. This agent is a mixture of several non heparin low molecular weight glycosaminoglycans, with proven anticoagulant efficacy, low cross-reactivity with the HIT antibody, and a half-time prolonged over 18-25 hours. The treatment regimen consisted in a i.v. bolus of 40-45 IU.kg-1 prior to each dialysis procedure, performed every two days. The platelet count increased to 200 G.L-1, seven days after discontinuing heparin injection, and remained stable during the administration of Orgaran. No other thrombosis occurred again. Each procedure of four hours duration was monitored with the plasma anti-Xa activity and APTT test. The mean anti-Xa plasma concentrations (0.44 +/- 0.55 IU.mL-1, 30 min after injection of Orgaran) were well correlated with APTT test (r = 0.73, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Markers of hemostasis and myocardial infarction in persons under 40 years of age]

Coronary disease before the age of 40 has special clinical and pathogenic features. The authors sought evidence of the existence of abnormalities of hemostasis markers in 39 patients aged under 40, several weeks after a myocardial infarction (MI). Blood samples were drawn a mean of 8 months after the MI. These laboratory studies included assay of C and S proteins, fibrinogen, clotting factors VII and VIII and antithrombin III, as well as detection of any possible circulating anticoagulant. Plasma levels of platelet factor 4 (PT4) and of beta-thromboglobulin (BTG) were measured in the same sample, enabling determination of the BTG/PF4 ratio. Only fibrinogen and plasma levels of platelet proteins were abnormal, revealing a significant difference between patients with multi-vessel disease and those with single vessel disease or free of severe angiographic lesions. Platelet activation appeared to persist some time after the MI, chiefly in patients with multi-vessel disease, and showing no relation to either age or treatment. Conclusions require prudence in view of difficulties in interpreting plasma assays of PF4 and of BTG.

Sleep apneas in high altitude residents (3,800 m)

The question is: to what extent periodic breathing usually observed in translocated subjects at high altitude affects normal and polycythemic residents of high altitude? Standard sleep parameters, chest wall movements, temperature of ventilated gas and arterial O2 saturation (SaO2) were continuously recorded in 7 normal highlanders (mean hematocrit: 51%) and 14 polycythemic highlanders (mean hematocrit: 68%) during one night in La Paz, 3,850 m, Bolivia. The patterns of breathing instability were analysed by two ways: measuring duration of apneas and counting all the oscillations of SaO2 greater than 1%. Normal and polycythemic highlanders displayed a wide intersubject variability with regard to breathing instability, hence no significant difference in the total number of apneas and oscillations of SaO2 could be evidenced between the 2 groups. However, the longest apneas and the highest number of oscillations of SaO2 were found in the polycythemic highlanders.

Periodic breathing and O2 saturation in relation to sleep stages at high altitude

This study was designed to compare sleep organization at high altitude (HA) and sea level (SL) and to estimate the extent periodic breathing (PB) negatively influences arterial O2 saturation (SaO2). Six lowlanders were studied at SL and after 3 weeks spent at 3,800 m (La Paz, Bolivia). Three EEG leads, EOG, submental EMG, chest and abdominal motion, temperature of ventilated gas, and SaO2 were polygraphically recorded. Comparison of HA and SL data disclosed that: 1) Sleep organization was identical, with the same percentage of REM and stage 4. 2) PB (cycle length: 20 s; central apnea: 9 s) occurred in three subjects during all stages of sleep except REM (43-60% of total sleep). A periodic lowering in heart rate occurred during ventilatory oscillation. 3) During PB, SaO2 oscillated very regularly from 78-90%, which resulted in a mean SaO2 value calculated during oscillations similar to that of the non-periodic breathers. We conclude that lung O2 uptake during PB is preserved.

Does arterial PCO2 interfere with hypoxia in muscular metabolism in man?

To answer the question whether PCO2 affects the muscular metabolism, PO2, PCO2, pH, lactic acid concentration and hemoglobin were measured in the efferent muscular venous blood from common flexor digitorum, during forearm rhythmic exercise corresponding to VO2max. Exercise was carried out either in hypocapnic hypoxia i.e. in permanent high altitude residents and translocated lowlanders, or in hypercapnic hypoxia i.e. in chronic obstructive lung disease (COLD) patients. The results show that, during exercise: i) PO2 in muscular venous blood remains around 20 Torr in normoxia and hypocapnic hypoxia and even higher (25 torr) in COLD patients, despite low arterial PaO2, and ii) arterial and/or local PCO2 play a role in the control of the muscular blood flow. But we cannot conclude that a change in PaCO2 affects muscular metabolism itself, because lactic acid in the muscular venous blood, that we used to check this effect, is likely dependent on mechanisms other than anaerobic glycolysis, such as a change in lactic acid efflux from the myocytes. The increase in muscular venous PCO2 may enhance the myocyte permeability to lactic acid during exercise.

Muscular venous blood metabolites during rhythmic forearm exercise while breathing air or normoxic helium and argon gas mixtures

The effects of breathing normoxic helium or argon gas mixture on the local muscular metabolism during exercise were compared to those of room air in four healthy subjects. For this purpose, PO2, PCO2, pH, the concentrations of lactate (LA), glucose (Gl) haemoglobin (Hb) and K+ and osmolarity were repeatedly measured in efferent muscular venous blood during 12 min of rhythmic forearm exercise and 16 min of recovery. The time courses and magnitude of the changes in PCO2, pH, [Gl], [Hb], [K+] and osmolarity during exercise and recovery were similar for breathing both the helium and argon gas mixtures. The main finding was that during exercise, the [LA] curve reached a peak value significantly higher by 25% under normoxic helium than under room air or normoxic argon breathing. This rise in [LA] was accompanied by a slight reduction in muscular venous PO2, too small to signify muscular hypoxia. The possibility that this decline in PO2 might be due to a shift in muscular metabolism towards lipid oxidation was confirmed by the lower muscular respiratory quotient observed during helium breathing. However, such a shift did not explain why [LA] rose during this breathing. The probable explanation is that helium facilitates LA diffusion out of the myocytes.

[Biochemical study of pollens of the genus Artemisia]

Pollens of three Artemisia: Artemisia vulgaris, Artemisia absinthium, Artemisia annua were separated by ion exchange chromatography and amino acids concentrations were measured. In any cases, the most important amino acid was proline, then asparagine + glutamine group, then gamma aminobutyric acid and alanine. An important level of histidine (8.1%) and hydroxyproline (6.2%) was found in Artemisia annua relative to the two other Artemisia species. The high histidine level, the precursor of histamine, found in the three kinds of Artemisia might be correlated with allergenic power of these weeds.

Bioenergetic and cardiovascular responses to exercise in residents at 2.850 m, with asymptomatic Chagas' disease

Cardiovascular and energetic responses at rest, during 30 min of exercise (mechanical output: 125 watts) and for a subsequent recovery period of 5 min were compared in two groups, each comprising 21 residents at an altitude of 2.850 m. One group was in the asymptomatic phase of Chagas' disease with positive serological tests for T. cruzi, whereas the other was without Chagas' disease (negative serological tests). The two groups were similar as regards age, weight-for-height, blood parameters, nutritional status and heart and lung functions, including heart rate and frontal plane QRS axis determinations. At rest, they differed in that maximal and minimal arterial blood pressures were slightly but significantly lower in the group with Chagas' positive serological tests than in the controls. During exercise and recovery, the only differences between them and the controls were that their minimal diastolic arterial blood pressure was significantly lower. In absolute values, the rises in arterial pressure due to exercise were exactly the same in the two groups. Maximal O2 uptake was identical in both groups, as was exercise steady state VO2. These findings indicate that the asymptomatic subjects with Chagas' disease had a normal work capacity and were not affected by high altitude.

Time course of muscular blood metabolites during forearm rhythmic exercise in hypoxia

O2 concentration, PO2, PCO2, pH, osmolarity, lactate (LA), and hemoglobin (Hb) concentrations in deep forearm venous blood were repeatedly measured during submaximal exercise of forearm muscles. Concentrations of arterial blood gases were determined at rest and during exercise. Experiments were conducted under normoxia and hypobaric hypoxia (PB = 465 Torr). In arterial blood, data obtained during exercise were the same as those obtained during rest under either normoxia or hypoxia. In venous muscular blood, PO2 and O2 concentration were lower at rest and during exercise in hypoxia. The muscular arteriovenous O2 difference during exercise in hypoxia was increased by no more than 10% compared with normoxia, which implied that muscular blood flow during exercise also increased by the same percentage, if we assume that exercise O2 consumption was not affected by hypoxia. Despite increased [LA], the magnitude of changes in PCO2 and pH in hypoxia were smaller than in normoxia during exercise and recovery; this finding is probably due to the increased blood buffer value induced by the greater amount of reduced Hb in hypoxia. Hence all the changes occurring in hypoxia showed that local metabolism was less affected than we expected from the decrease in arterial PO2. The rise in [Hb] that occurred during exercise was lower in hypoxia. Possible underlying mechanisms of the [Hb] rise during exercise are discussed.

Changes in rectal and mean skin temperature in response to suggested heat during hypnosis in man

Rectal temperature, mean skin temperature and heart rate were recorded in 7 subjects during hypnosis, induced either alone or while sensations of heat were suggested. During hypnosis alone, a fall in the heart rate of about 10 beat X min-1 was the only autonomic response observed; body temperatures were unaltered. In contrast, during hypnosis with suggestion of heat, the following changes occurred: (1) Mean rectal temperature decreased 0.20 degrees C (p less than 0.05) within 50 min. Its mean time course differed significantly from that for hypnosis alone (p less than 0.001). (2) Comparison of individual rectal temperature time sequences showed that in fact this temperature only declined in 4 subjects out of 7, and tended to form a plateau located 0.35 degrees C below the value of the preceding waking state. Despite reinforcement of heat suggestion, the plateau continued until the end of the hypnotic trance. (3) Mean skin temperature tended to rise. (4) When hypnosis with suggestion ceased, both rectal and skin temperatures very slowly returned to their levels during the preceding waking state.

Intersubject viability in growth hormone time course during different types of work

This study addresses the question of variability of immunoreactive human growth hormone (IRHGH) response to the following types of muscular exercise. 1) One hour of submaximal exercise with restarting for 30 min after 20 min of recovery. Three types of responses were observed: a rise of [IRHGH] occurred in response to muscular activity; [IRHGH] was maintained at rest level during the first bout and then rose in the second bout; or [IRHGH] rose during the first bout and was no longer modified by the restarting. 2) Thirty minutes of heavy exercise. In some subjects [IRHGH] change was almost linear with time, reaching very high values and dropping as soon as exercise had stopped, whereas in others peak values were similar to those of submaximal exercise but, in contrast, plateaued during recovery. 3) One hour of exercise performed either continuously or with alternate sequences of 30-s exercise and 30-s pause. In intermittent exercise, some subjects displayed a similar time course of [IRHGH] as in continuous exercise and others displayed markedly high values. 4) One hour of submaximal exercise at three different intensities carried out at ambient temperatures of 24 and 33 degrees C. At 33 degrees C, in some subjects, [IRHGH] time course at the three intensities was unchanged at 33 degrees C compared with that at 24 degrees C, whereas the maximal value increased in another subject up to 150 ng X ml-1. A significant intrasubject consistency to a given type of exercise was evident over several months. The study emphasizes that caution should be used in drawing definite conclusions from averaged results with high variability.

Time course of plasma growth hormone during exercise in humans at altitude

The effects of hypoxia on growth hormone release during submaximal exercise were studied 1) in eight highlanders (HL) at 3,800 m (La Paz, Bolivia); and 2) in five lowlanders (LL) at sea level, after 5 days' sojourn at 2,850 m, and while breathing a hypoxic gas mixture (FIO2 - 0.15 corresponding to PIO2 at 2,850 m) 1 mo after returning to sea level. Concentrations of immunoreactive human growth hormone ([IRHGH]), blood glucose ([G]), free fatty acids ([FFA]), and lactate ([LA]) were determined repeatedly at rest, during 1 h of exercise, and after 1 h of recovery. Compared with LL, in HL, the resting value of [IRHGH] is higher, the rate of increase at the beginning of exercise is faster and earlier, but the mean maximal value reached at the end of exercise is similar. The response pattern in LL during the early stages of exposure to hypoxia resembles that of HL. No correlation was found between peak values of [IRHGH] and maximal values of [LA] and [FFA] or minimal values of [G]. The possible causes of the different time sequence observed in growth hormone dynamics during hypoxia are suggested: an alteration of the clearance of the hormone through a more pronounced reduction of hepatic blood flow or a difference in the state of the pituitary gland before the exercise begins. The study emphasizes the importance of characterizing time sequence of [IRHGH] by parameters other than the maximal value, e.g., by mean concentration computed over exercise period.

Properties of the cytoplasmic progestin-binding protein in the rabbit uterus

An exchange assay for the measurement of total cytoplasmic progestin binding sites has been developed on rabbit uterine cytosol using the highly potent progestin, R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) labelled to a high specific activity. This compound has several advantages over progesterone: it is not bound by plasma corticosteroid binding globulin; it has high affinity for the progestin receptor; it binds virtually as fast as progesterone to the receptor, but the complex formed dissociated 8 times slower; its binding is not displaced by more than 2% by compounds devoid of progestational activity (estrogens, testosterone, dexamethasone, aldosterone). Bound endogenous progesterone was exchanged by tritiated R 5020 in a time compatible with receptor stability. At 0 C, total exchange of filled sites occurred in less than 4 h; at this temperature the R 5020-receptor complex was stable for at least 28 h. The conformation of the R 5020-receptor complex was investigated in sucrose density gradients under various experimental conditions. Unlike progesterone, it was possible to detect a 7S peak in uterine cytosol obtained from rabbits injected with a tracer dose of [3H]R 5020 1 h prior to sacrifice.

[Tumor induction in mice treated with hydrocortisone and innoculated with polyoma transformed hamster cells]

Tumors have been induced in hydrocortisone treated Mice innoculated with wild-type polyoma transformed Hamster cells. The filtrate from these tumors infects Mouse embryo cells and induces the production of polyoma virus. The polyoma virus has been characterised in the infected cells with anti-polyoma capsid serum.