The spiral arteries at the level of the decidual-myometrial junction in the placental bed were examined histologically in 93 biopsies. Of these, 23 originated from normal uncomplicated pregnancies, 30 from pre-eclamptic and 40 from otherwise complicated pregnancies. The association of the 'physiological changes' of the spiral artery with uncomplicated pregnancy and their absence in pre-eclampsia, as noted by Brosens and others, has been confirmed. In addition, in pregnancies without pre-eclampsia, these changes were significantly more often absent with fetal growth retardation. The hypothesis is put forward that hypertension of pregnancy is a compensatory mechanism to ensure an adequate blood supply to the placenta when the 'physiological changes' fail to occur.

Using polyclonal and monoclonal antihistone antisera, histones were identified in all patients with DPGN and their presence was associated with a decrease of HS staining. Nucleosomes were identified in five of 11 patients with DPGN and in two of six patients with MGN. This is the first demonstration of nucleosomes in glomerular deposits in SLE nephritis.

Lymphoid tissue of 42 patients with Hodgkin's disease was studied with immunohistological techniques on the light microscopic and ultrastructural level. The presence of IgG in some Reed‐Sternberg (R‐S) cells was confirmed, and in addition serial sections and a double staining technique revealed that these cells also contained both kappa and lambda light chains. Furthermore two serum proteins, human serum albumin and alpha‐1‐antitrypsin, were demonstrated in the same positive R‐S cells. The ultrastructural localization of the immunoglobulin and of human serum albumin was not related to any protein synthesizing organelle or to structures related to endocytosis. It is suggested that the presence of immunoglobulin in R‐S cells is the result of a disturbance of the cell wall integrity with subsequent nonspecific diffusion of immunoglobulin and other serum proteins into the cell. The presence of IgG therefore can not be taken as an argument for a B‐cell origin of R‐S cells. Possible mechanisms for the cell wall damage are discussed. Cancer 42:1793–1803, 1978.

Summary. Ninety‐three placental bed biopsies containing a segment of a spiral artery at the level of the decidual–myometrial junction (53 with and 40 without physiological changes) were histologically investigated for depth of trophoblastic penetration of the uterine wall, formation of trophoblastic multinucleated giant cells and the enzyme histochemical characteristics of the interstitial (stromal) and vascular (intramural) trophoblast. The depth of trophoblastic penetration was not related to the presence or absence of the physiological changes. Conversely, in the absence of physiological changes, a significant accumulation of multi‐nucleated giant cells at the decidual–myometrial junction was found before 36 weeks of gestation. The enzyme histochemical characteristics of the placental bed trophoblast suggest a stromal migration of trophoblast to the proximal (decidual–myometrial) part of the spiral artery whereas the distal part might be invaded by intraluminal (upstream) invasion. The hypothesis is put forward that in the absence of physiological changes a disturbed stromal migration is caused by intrinsic (trophoblastic) or extrinsic (interstitial of vascular) factors expressed by the augmentation of the multinucleated cells at the decidual–myometrial junction.

A 62-year-old woman developed subacute renal failure after the repeated administration of ifosfamide (IFX), despite its combination with continuous sodium 2-mercaptoethane sulfonate (mesna) infusion. Biopsy findings, the possible underlying mechanism, and the existing literature are discussed.