The life and scientific work of William R. Evitt (1923-2009)

Occasionally (and fortunately), circumstances and timing combine to allow an individual, almost singlehandedly, to generate a paradigm shift in his or her chosen field of inquiry. William R. (‘Bill’) Evitt (1923-2009) was such a person. During his career as a palaeontologist, Bill Evitt made lasting and profound contributions to the study of both dinoflagellates and trilobites. He had a distinguished, long and varied career, researching first trilobites and techniques in palaeontology before moving on to marine palynomorphs. Bill is undoubtedly best known for his work on dinoflagellates, especially their resting cysts. He worked at three major US universities and spent a highly significant period in the oil industry. Bill's early profound interest in the natural sciences was actively encouraged both by his parents and at school. His alma mater was Johns Hopkins University where, commencing in 1940, he studied chemistry and geology as an undergraduate. He quickly developed a strong vocation in the earth sciences, and became fascinated by the fossiliferous Lower Palaeozoic strata of the northwestern United States. Bill commenced a PhD project on silicified Middle Ordovician trilobites from Virginia in 1943. His doctoral research was interrupted by military service during World War II; Bill served as an aerial photograph interpreter in China in 1944 and 1945, and received the Bronze Star for his excellent work. Upon demobilisation from the US Army Air Force, he resumed work on his PhD and was given significant teaching duties at Johns Hopkins, which he thoroughly enjoyed. He accepted his first professional position, as an instructor in sedimentary geology, at the University of Rochester in late 1948. Here Bill supervised his first two graduate students, and shared a great cameraderie with a highly motivated student body which largely comprised World War II veterans. At Rochester, Bill continued his trilobite research, and was the editor of the Journal of Paleontology between 1953 and 1956. Seeking a new challenge, he joined the Carter Oil Company in Tulsa, Oklahoma, during 1956. This brought about an irrevocable realignment of his research interests from trilobites to marine palynology. He undertook basic research on aquatic palynomorphs in a very well-resourced laboratory under the direction of one of his most influential mentors, William S. ‘Bill’ Hoffmeister. Bill Evitt visited the influential European palynologists Georges Deflandre and Alfred Eisenack during late 1959 and, while in Tulsa, first developed several groundbreaking hypotheses. He soon realised that the distinctive morphology of certain fossil dinoflagellates, notably the archaeopyle, meant that they represent the resting cyst stage of the life cycle. The archaeopyle clearly allows the excystment of the cell contents, and comprises one or more plate areas. Bill also concluded that spine-bearing palynomorphs, then called hystrichospheres, could be divided into two groups. The largely Palaeozoic spine-bearing palynomorphs are of uncertain biological affinity, and these were termed acritarchs. Moreover, he determined that unequivocal dinoflagellate cysts are all Mesozoic or younger, and that the fossil record of dinoflagellates is highly selective. Bill was always an academic at heart and he joined Stanford University in 1962, where he remained until retiring in 1988. Bill enjoyed getting back into teaching after his six years in industry. During his 26-year tenure at Stanford, Bill continued to revolutionise our understanding of dinoflagellate cysts. He produced many highly influential papers and two major textbooks. The highlights include defining the acritarchs and comprehensively documenting the archaeopyle, together with highly detailed work on the morphology of Nannoceratopsis and Palaeoperidinium pyrophorum using the scanning electron microscope. Bill supervised 11 graduate students while at Stanford University. He organised the Penrose Conference on Modern and Fossil Dinoflagellates in 1978, which was so successful that similar meetings have been held about every four years since that inaugural symposium. Bill also taught many short courses on dinoflagellate cysts aimed at the professional community. Unlike many eminent geologists, Bill actually retired from actively working in the earth sciences. His full retirement was in 1988; after this he worked on only a small number of dinoflagellate cyst projects, including an extensive paper on the genus Palaeoperidinium

Defective polymorphonuclear leukocyte metabolism and function in canine cyclic neutropenia

Humans and grey collie dogs with cyclic neutropenia are known to suffer from an increased rate of bacterial infection. Because of the previously described microanatomic abnormalities of lysosome formation found in the polymorphonuclear leukocytes (PMNs) of dogs with canine cyclic neutropenia, studies of these cells were undertaken. PMNs from grey collie dogs were found to have significant metabolic and functional abnormalities when compared with normal collie PMNs. These included abnormally increased postphagocytic C1-glucose oxidation, decreased iodination of trichloroacetic acid-precipitable protein in the resting and phagocytizing state, decreased levels of intracellular myeloperoxidase,and a bactericidal defect against a variety of bacteria. Phagocytosis was normal. These abnormalities appear to differ from those previously described in the PMNs of patients with chronic granulomatous disease of childhood and the Chediak-Higashi syndrome and more closely resemble those seen in hereditary myeloperoxidase deficiency. Thus, the studies reported here demonstrate defective PMN function in a disease state previously believed to be a model only of periodic hematopoiesis.</jats:p

Defective polymorphonuclear leukocyte metabolism and function in canine cyclic neutropenia

Abstract Humans and grey collie dogs with cyclic neutropenia are known to suffer from an increased rate of bacterial infection. Because of the previously described microanatomic abnormalities of lysosome formation found in the polymorphonuclear leukocytes (PMNs) of dogs with canine cyclic neutropenia, studies of these cells were undertaken. PMNs from grey collie dogs were found to have significant metabolic and functional abnormalities when compared with normal collie PMNs. These included abnormally increased postphagocytic C1-glucose oxidation, decreased iodination of trichloroacetic acid-precipitable protein in the resting and phagocytizing state, decreased levels of intracellular myeloperoxidase,and a bactericidal defect against a variety of bacteria. Phagocytosis was normal. These abnormalities appear to differ from those previously described in the PMNs of patients with chronic granulomatous disease of childhood and the Chediak-Higashi syndrome and more closely resemble those seen in hereditary myeloperoxidase deficiency. Thus, the studies reported here demonstrate defective PMN function in a disease state previously believed to be a model only of periodic hematopoiesis.</jats:p

Long-term remission from acute myelogenous leukemia after bone marrow transplantation and recovery from acute graft-versus-host reaction and prolonged immunoincompetence

Abstract A 19-yr-old boy has been in continuous complete remission from acute myelogenous leukemia for 3 yr after allogeneic bone marrow transplantation prepared with combination chemotherapy. During the first year post-transplant, however, the patient developed near-fatal graft-versus-host reaction followed by 11 severe viral and bacterial infections. Immune evaluation during this period revealed multiple defects which were not present prior to transplantation, nor present in the transplant donor: diminution of lymphoid tissue, decline of all immunoglobulin subtypes, deletion of secretory immunoglobulin, disappearance of isohemagglutinins, loss of antibody to diptheria and tetanus toxoids, cessation of cutaneous hypersensitivity to mumps antigen, and inhibition of serum opsonizing activity. The patient was also unable to develop normal humoral or cellular reactivity to brucella antigen, keyhole limpet hemocyanin, or dinitrochlorobenzene. This patient's course illustrates the severity and chronicity of immunoincompetence associated with allogeneic marrow grafting, the importance of early detection and rigorous treatment of infectious disease in these patients, and the need for improved immunologic reconstitution in human marrow transplantation. It also indicates that complete recovery from the immune defects is possible, and that long- term remission from acute myelogenous leukemia can be achieved with allogeneic marrow transplantation.</jats:p

Long-term remission from acute myelogenous leukemia after bone marrow transplantation and recovery from acute graft-versus-host reaction and prolonged immunoincompetence

A 19-yr-old boy has been in continuous complete remission from acute myelogenous leukemia for 3 yr after allogeneic bone marrow transplantation prepared with combination chemotherapy. During the first year post-transplant, however, the patient developed near-fatal graft-versus-host reaction followed by 11 severe viral and bacterial infections. Immune evaluation during this period revealed multiple defects which were not present prior to transplantation, nor present in the transplant donor: diminution of lymphoid tissue, decline of all immunoglobulin subtypes, deletion of secretory immunoglobulin, disappearance of isohemagglutinins, loss of antibody to diptheria and tetanus toxoids, cessation of cutaneous hypersensitivity to mumps antigen, and inhibition of serum opsonizing activity. The patient was also unable to develop normal humoral or cellular reactivity to brucella antigen, keyhole limpet hemocyanin, or dinitrochlorobenzene. This patient's course illustrates the severity and chronicity of immunoincompetence associated with allogeneic marrow grafting, the importance of early detection and rigorous treatment of infectious disease in these patients, and the need for improved immunologic reconstitution in human marrow transplantation. It also indicates that complete recovery from the immune defects is possible, and that long- term remission from acute myelogenous leukemia can be achieved with allogeneic marrow transplantation.</jats:p