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Biomedical subjects

P Peters

Publications and source records attributed to P Peters.

96 records · Page 6Linked to original sources
PubMedDate not supplied

[Cement-free cup and cemented shaft--concept of a hybrid solution and results of a 3-to-6-year clinical experience].

Report about the Marburg Hybrid THA using a cementless cup and a cemented stem. The acetabular component consists of an hemispheric inner polyethylene cup and an outer five-layer sintered titanium wire mesh fused together. The socket is primarily anchored by one peg as well as 2 self-stabilizing titanium nails. The forged titanium alloy stems are meeting all the requirements of the latest biomechanic research. A total of 292 Hybrid THA were implanted in 273 patients from 1. 8. 1986 to 1. 1. 1989. 6 patients (2.1%) had to undergo THA exchange surgery (1 early, 3 late infections, 1 acetabular fracture after fall, 1 loosened stem). The clinical data of 62 patients (21.2%) had to be disregarded for various reasons. Thus the data of 212 (72.6%) implanted THA in 194 patients were analyzed. 204 of the analyzed THA (96.2%) judged the result of the operation as good or very good. Radiolucency at the bone-titanium-interface of the cementless cups was present in 60 of 212 cases (28.3%), in revision operations twice as often as in primary implantations. There were no signs of progression. Radiolucency at the bone-cement-interface of the cemented stems was present in 27 of 212 cases (12.8%), with radiolucencies > 1 mm only occurring in area 7 of Gruen (1979). The overall results are thus very promising and support the concept of a hybrid solution for THA.

Adult↗
PubMedDate not supplied

The effects of hyperthermia in bone marrow purging of breast cancer.

The number of autologous bone marrow transplants done for solid tumours, particularly breast cancer, has risen steadily over the last ten years. The role of bone marrow or peripheral blood progenitor cell purging in transplantation is incompletely understood. Theoretically, the reinfusion of untreated bone marrow containing tumour cells might result in relapse in some patients treated with high-dose chemotherapy and hematopoietic support. Therefore, safe and effective purging techniques may increase long-term, disease-free survivorship. In this study, hyperthermia was evaluated for its ability to purge CAMA-1 breast cancer cells from normal human bone marrow. Between two and nine trials of a range of temperatures (42-45 degrees C) and durations of treatment (1-4 h) were performed. The effect of hyperthermia on normal bone marrow alone and in mixes with breast cancer cells was also evaluated. Hyperthermia (45 degrees C, 4 h) produced > 5 logs of CAMA-1 cell kill. Exposures of 45 degrees C for 2 h and 44 degrees C for 4 h resulted in approximately three logs of cell kill, corresponding to < 1% survival of clonogenic cells. Normal bone marrow was considerably more vulnerable to heat treatments, however, with approximately 1% of progenitors remaining clonogenic after exposure of 43 degrees C for 2 h and 44 degrees C for 1 h. Therefore, although hyperthermia is able to achieve adequate CAMA-1 breast cancer cell kill, it remains more toxic to normal bone marrow as a purging method. To make hyperthermia useful in purging systems, mechanisms to selectively alter thermal sensitivity must be pursued.

Bone Marrow Purging↗
PubMedDate not supplied

Steal syndrome after kidney transplantation caused by A-V fistula at the thigh.

The cases of two low-weight children are reported, who became dialysis patients at the age of 2.5 and 5.5 years, respectively, and were hemodialyzed by way of a bovine artgraft A-V fistula at the thigh. One year later, both patients were successfully transplanted with a cadaveric kidney. Immunosuppression was carried out in the first 3 weeks with prednisone, azathioprine and ciclosporin, later on with prednisone and ciclosporin. The first patient (A-V fistula at the right thigh) was transplanted on the right fossa iliaca. After an acute rejection episode 11 days after kidney transplantation, successfully treated by prednisolone pulse therapy, there was another episode similar to rejection after 5 weeks. This episode was complicated by a hypertensive crisis with convulsion. Again bolus injections of prednisolone were performed, but kidney function declined rapidly. Diagnostics (perfusion scintigraphy with Tc-DTPA, digital substraction angiography) demonstrated hypoperfusion of the graft, caused by a steal syndrome due to the A-V fistula in the groin. Ligation of the fistula resulted in rapid improvement of renal function and decrease in blood pressure occurred. The second patient was transplanted on the fossa iliaca contralaterally of the A-V fistula in the groin. Twenty-one days after kidney transplantation we saw a rejection episode accompanied by cytomegalovirus (CMV) infection. After bolus injection of prednisolone and CMV-antibody treatment in the beginning, stabilization of kidney function was seen. But the following week we experienced an unexplainable deterioration of graft function followed by progressive acute renal failure. Again, a steal syndrome due to the contralateral A-V fistula could be demonstrated. After ligation of the A-V fistula renal function normalized within 14 days. Currently graft function is satisfactory in both patients.

Arteriovenous Shunt, Surgical↗