Immunologic monitoring and immunotherapy in Ewing's sarcoma

Summary Serial immunological monitoring was performed on 31 patients with Ewing's sarcoma who were on a randomized immunotherapy trial with BCG administered by dermal scarification with a Heaf gun. Patients were skin-tested for delayed hypersensitivity reactions (DCHR) to recall antigens and extracts of tumor cells, and with keyhole limpet hemocyanin (KLH). In vitro testing consisted of lymphocyte counts, percentages of cells forming rosettes with sheep erythrocytes at 29° C and at 4° C, and leukocyte migration inhibition to tuberculin (PPD) and to 3 M KCl extracts of tumor cells. At the time of diagnosis, nearly all patients had positive DCHR to mumps and streptococcal antigens and were negative to PPD. Neither the skin tests nor the lymphocyte counts at this time gave useful prognostic information. In tests during and after therapy, the patients who responded and remained free of detectable disease had a higher incidence of DCHR to KLH and of rosette values in the normal range than did the patients who developed recurrent disease. The BCG immunotherapy had no apparent effect on immunologic parameters except for conversion of reactions to PPD.     

Chemical biology: Paper alert

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in chemical biology.     

A critical review on brain and heart axis response in COVID-19 patients: Molecular mechanisms,mediators, biomarkers,and therapeutics

Since the outbreak of highly virulent coronaviruses, significant interest was assessed to the brain and heart axis (BHA) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-affected patients. The majority of clinical reports accounted for unusual symptoms associated with SARS-CoV-2 infections which are of the neurological type, such as headache, nausea, dysgeusia, anosmia, and cerebral infarction. The SARS-CoV-2 enters the cells through the angiotensin-converting enzyme (ACE-2) receptor. Patients with prior cardiovascular disease (CVD) have a higher risk of COVID-19 infection and it has related to various cardiovascular (CV) complications. Infected patients with pre-existing CVDs are also particularly exposed to critical health outcomes. Overall, COVID-19 affected patients admitted to intensive care units (ICU) and exposed to stressful environmental constraints, featured with a cluster of neurological and CV complications. In this review, we summarized the main contributions in the literature on how SARS-CoV-2 could interfere with the BHA and its role in affecting multiorgan disorders. Specifically, the central nervous system involvement, mainly in relation to CV alterations in COVID-19-affected patients, is considered. This review also emphasizes the biomarkers and therapy options for COVID-19 patients presenting with CV problems.     

An oligomeric hydroxyphenylalanine in malignant melanoma: a new type of melanogen

A new compound designated MM2 has been isolated by ion exchange chromatography from tumor extracts and urine of patients with malignant melanoma. This material was purified by G-25 sephadex chromatography and studied by standard spectroscopic techniques including nuclear magnetic resonance, ultraviolet, infrared, and mass spectrometry. These data are consistent with an oligomeric structure of four dihydroxyphenylalanine subunits with subunit bonding made between phenyl rings. The appearance of large quantities of such an oligomer in malignant melanoma suggests the existance of intermediate stages of polymerization of melanin precursors before the final melanin high polymer is formed.