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Biomedical subjects

S Meyer

Publications and source records attributed to S Meyer.

349 records · Page 20Linked to original sources

Sterile versus non-sterile dialysis fluid in chronic hemodialysis treatment.

As the quality of water in the dialysis fluid varies considerably, and in view of the fact that endotoxin or active derivatives can cause acute side effects in patients, the dialysis fluid must be sterile. Therefore, we introduced ultrafiltration of dialysis fluid before entering the dialyzer. Fifteen patients, (ten women, five men) were treated for 4 weeks with nonsterile, and then with sterile dialysis fluid. The bacterial loading in the dialysis fluid before hemodialysis was 1.34 X 10(5)/ml, and after hemodialysis 2.9 X 10(3)/ml; the endotoxin concentration was high and varied between less than 1 EU/ml and greater than 10 EU/ml before and after hemodialysis. After ultrafiltration of the dialysis fluid by a polyamide hollow fiber membrane, all samples were free of bacteria and the concentration of endotoxin was lower than the detectable limit (less than 0.03 and less than 0.5 EU/ml). With ultrafiltration of dialysis fluid we can obtain sterile dialysate, which is endotoxin free. Interleukin-1 and tumor necrosis factor in the patients with ultrafiltration was significantly lower than without ultrafiltration.

Adult↗

Influence of helix formation on cis/trans isomerism of Xaa-Pro bonds flanking the helical segment.

The trifluoroethanol (TFE)-induced formation of alpha-helical structures in the peptide hormone calcitonin (salmon) was studied using limited proteolysis combined with capillary zone electrophoresis. A low TFE content in TFE/buffer mixtures was insufficient to introduce secondary structure, but two Lys-Leu bonds were found to have become inaccessible to proteolysis with clostripain. The influence of increasing helical degree of the Thr6-Lys18 (or Thr6-Tyr22 in the trans conformation) segment on the cis/trans isomerization of the adjacent Tyr22-Pro23 peptide bond was examined by means of isomer specific proteolysis. Results indicate that the helix dipole does not influence the cis/trans equilibrium distribution of the flanking Tyr22-Pro23 bond but considerably increases its isomerization rate Ko-->t.

Amino Acid Sequence↗

Ectopic prolactinoma in the clivus.

BACKGROUND: Ectopic pituitary adenomas are rare. Only 29 cases are reported in the literature. The clivus was involved in some cases but sella turcica was occasionally involved. CLINICAL PRESENTATION: Headache was the first symptom of a 47-year-old woman. Radiological examination diagnosed a clivus tumour. No connection with the pituitary gland was observed. Pre-operative diagnosis was metastasis of an unknown cancer. INTERVENTION: By a transphenoidal approach, we removed a haemorrhagic tumour. No connection between the normal pituitary gland and the tumour was observed. Neuropathological analysis showed a prolactinoma. CONCLUSION: We report a rare case of an ectopic prolactinoma in the clivus unrelated to the pituitary gland. Only one other case has been reported in the literature.

Choristoma↗