D-T neutron generator development for cancer therapy. 1980 annual progress report

This report summarizes the work completed during the first year of a two-year grant by NCI/HEW to investigate the feasibility of developing a D-T neutron generator for use in cancer therapy. Experiments have continued on the Target Test Facility (TTF) developed during a previous grant to investigate high-temperature metal hydrides for use as target materials. The high voltage reliability of the TTF has been improved so that 200 kV, 200 mA operation is now routine. In recent target tests, the D-D neutron production rate was measured to be > 1 x 10/sup 11//s, a rate that corresponds to a D-T neutron production rate of > 1 x 10/sup 13//s - the desired rate for use in cancer therapy. Deuterium concentration depth profiles in the target, measured during intense ion beam bombardment, show that deuterium is depleted near the surface of the target due to impurities implanted by the ion beam. Recent modifications of the duopigatron ion source to reduce secondary electron damage to the electrodes also improved the ion source efficiency by about 40%. An ultra high vacuum version of the TTF is now being constructed to determine if improved vacuum conditions will reduce ion source impurities to a sufficiently low level that the deuterium near the surface of the target is not depleted. Testing will begin in June 1980

Acesso vascular para hemodiálise com cateter temporário de duplo lúmen em cães com insuficiência renal aguda Hemodialysis vascular access with temporary double-lumen catheter in dogs with acute renal failure

A hemodiálise é uma modalidade terapêutica que pode sustentar a vida do paciente com insuficiência renal aguda (IRA), enquanto este recupera a função renal. Para sua realização, é necessário estabelecer circulação extracorpórea, para que seja realizada a filtração do sangue, impondo a necessidade de um acesso vascular viável e eficiente. O objetivo deste estudo foi avaliar a eficiência e as complicações do acesso vascular para hemodiálise (HD), com cateter temporário de duplo lúmen inserido na veia jugular externa. Foram estudados 10 cães com IRA induzida por gentamicina, submetidos a sessões diárias de HD, com duração de uma hora, até a recuperação da função renal ou óbito. Foram realizadas 104 sessões de HD nos animais estudados, observando-se necessidade de troca do cateter em sete sessões (6,7%), devido à obstrução do lúmen do cateter em seis sessões (5,8%) ou por saída acidental do mesmo em uma sessão (1,0%). Não se observou migração do cateter, infecção, hemorragia ou hematoma no local de entrada do cateter na pele, obtendo-se fluxo sanguíneo patente em 90,4% das sessões. Concluiu-se que o acesso vascular na veia jugular externa com cateter temporário de duplo-lúmen mostrou-se viável, com ocorrência de poucas complicações, sendo, portanto, indicado como forma de acesso para a circulação extracorpórea para HD em cães com IRA.<br>Hemodialysis is a therapeutic procedure that can sustain the patient's life in acute renal failure (ARF), during the renal function recover. To perform hemodialysis (HD), an extracorporeal circulation is established to blood filtration, imposing the need of a viable and efficient vascular access. The aim of this study was to evaluate the effectiveness and complications of the HD vascular access with temporary double-lumen catheter inserted into the external jugular vein. Ten mongrel dogs with ARF, induced by gentamicin administration, were submitted to daily hemodialysis for one hour, until renal function recover or death. A total of 104 HD sessions were performed. Catheter replacement was accomplished in seven sessions (6.7%), due to catheter lumen mechanical obstruction in six sessions (5.8%) or accidental catheter output in one session (1.0%). No catheter migration, infection, bleeding or haematoma around the catheter insertion site was found. Effective blood flow rates were observed in 90.4% HD sessions. In conclusion, the vascular access in jugular external vein with temporary double-lumen catheter was valuable, with few complications, and should be indicated to vascular access in extracorporeal circulation to HD in ARF dogs