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Biomedical subjects

M L Willoughby

Publications and source records attributed to M L Willoughby.

12 recordsLinked to original sources

Two malignant peripheral primitive neuroepithelial tumor cell lines established from consecutive samples of one patient: characterization and cytogenetic analysis.

A 6-year-old girl presented with a tumor of the right shoulder involving bone, adjacent soft tissue, and regional lymph nodes. The conventional histologic diagnosis was ambiguous, initially suggesting lymphoma. After relapse on lymphoma therapy, reevaluation with additional multiple diagnostic techniques performed on the biopsy tissue and on two cell lines derived from the biopsies established the diagnosis of a primitive neuroepithelial tumor of bone and soft tissue. This was strongly supported by 1) focal rosette formation by the tumor cells and positive immunostaining for neuron-specific enolase and synaptophysin, with absent staining for leukocyte common antigen; 2) at the ultrastructural level, formation of cellular processes containing microtubules, a paucity of neurosecretory granules, absence of synaptic junctions, formation of long "intermediate" junctions between cells, and, in culture, widespread development of rosettes; 3) marked surface positivity to W 6/32 and negativity to HSAN 1.2 antibodies; and 4) elevated expression of MYC and lack of overexpression of MYCN oncogenes. Numerical and structural abnormalities were present in the karyotype, but the expected t(11;22)(q24;q12) was not present in the tumor-involved marrow or in either of the established tumor cell lines, although there was an interstitial deletion of 11q involving breakpoints in q21 and q23.

Biomarkers, Tumor

Continuous-flow plasmapheresis in management of severe rhesus disease.

Eight patients with severe rhesus disease and expected fetal loss were treated by intensive plasmapheresis using a continuous-flow cell separator. Plasmapheresis was started at 16-27 weeks' gestation, and continued until planned intrauterine transfusion or until the infant was delivered or the rhesus disease became uncontrolled again. Altogether 24 to 2371 of plasma was exchanged over periods ranging from seven to 16 weeks. In seven of the eight patients the anti-D concentration fell during the period of plasmapheresis. Amniotic fluid spectrophotometry values remained below those recorded in the preceding pregnancy in six out of seven women. In five patients an attempt was made to control the rhesus disease by plasmapheresis alone, and two of these women delivered infants who survived. In the other three cases the infants died, one from the idiopathic respiratory distress syndrome and the other two in utero. These preliminary findings suggest that intensive plasmapheresis with a cell separator may reduce fetal haemolysis is delivered. Nevertheless, plasmapheresis may best be used to reduce haemolysis until intrauterine transfusions may be given more safely after 30 weeks' gestation.

Amniocentesis

Cryopreservation of human granulocytes in liquid nitrogen.

Human granulocytes (PMNL) were successfully cryopreserved for up to 14 months. The PMNL (1-2 X 10(7)/ml) were stored in 2-ml ampoules in the gas phase of liquid nitrogen at a temperature between -160 degrees C and -196 degrees C using dimethylsulphoxide (DMSO 10%) as cryoprotectant. Morphology and phagocytic and bactericidal capacity were best preserved by adding fetal calf serum to the freezing mixture, by using an interrupted cooling process, by washing the thawed PMNL in fresh freeze-dried plasma, and centrifuging at 600 g for no more than two minutes. Careful post-thaw handling of the cells was an important factor in preserving function. These preliminary studies indicate that useful numbers of PMNL can be recovered in a functional state after storage for long periods in liquid nitrogen.

Blood Bactericidal Activity

Treatment of overt meningeal leukaemia in children: results of second MRC meningeal leukaemia trial.

After induction ofmeningeal remission by a course of intrathecal methotrexate patients were randomly allocated to receive either cranial irradiation or craniospinal irradiation. Patients being treated for their first meningeal relapse were randomised separately from those in their second or subsequent relapse. All eight patients in their first relapse who were given cranial irradiation alone developed further meningeal recurrence (median length of remission 15 weeks) compared with only two out of nine given craniospinal irradiation (median length of remission at least 99 weeks). Four of the nine patients given craniospinal irradiation were alive and without further meningeal relapse two and a half to four years after treatment. Craniospinal irradiation produced no such advantage for patients entering the trial in their second or subsequent meningeal relapse.

Brain

Granulocyte transfusion in treatment of infected neutropenic children.

Thirty episodes of infection in severely neutropenic children with acute leukaemia and aplastic anaemia resistant to antibiotics were treated with total of 51 granulocyte transfusions collected from normal donors by means of an Aminco continuous flow cell separator. The mean granulocyte increment in the recipients was 820/mm3 at 1 hour and 307/mm3 at 15 hours post-transfusion and it showed a correlation with the number of cells transfused, the size of the child, and his pretransfusion granulocyte count. Fifteen (50%) episodes responded clinically by 24 hours and 23 (77%) by 5 days post-transfusion. Two more children recovered more slowly and 5 died. Poor response was associated with multiple-site infections and with a prolonged period of infection before granulocyte transfusion, but the primary diagnosis did not influence the outcome. We conclude that granulocyte transfusion significantly reduces the mortality and morbidity from infection in neutropenic children with acute leukaemia.

Adolescent

Immune status of children with and without severe infection during remission of malignant disease.

The immune status of children with malignant disease in remission was assessed usingvarious immune function tests. Children with infections had significantlymore neutropenia, hypogammaglobulinaemia, and impaired cell-mediated immune responses than those without. These two groups combined had much more absolute lymphopenia and impairment of both cell-mediated immunity and antibody-producing capacity thancontrol children with non-malignant conditions. Regular immunological evaluation isrecommended for children with malignant disease when new intensive treatment schedules are under trial and for individual patients particularly prone to develop infections during treatment.

Antibody Formation