Ultrastructural changes of the placenta in cases of preeclampsia

The placenta plays vital roles during fetal development and growth. The ultrastructure of the placenta together with remodeling of the uterine spiral arteries are very important to maintain the utero-placental blood flow. Preeclampsia (PE) is a multifactorial disorder with abnormal placentation affecting the mother and fetus. The aim of this study was to study the ultrastructural abnormalities of the placenta in cases of PE. The placentas of 10 PE women and 10 controls were studied. Women of PE group were delivered by caesarian section while seven control women were delivered vaginally, and three by caesarian section. Placental samples were studied both morphologically and histologically by light and transmission electron microscopy. Light microscopic study of control placentas showed numerous microvilli, few syncytial knots, thin-walled blood vessels. PE placentas showed reduced number of microvilli with numerous syncytial knots, thick-walled vessels, edematous spaces, fibrotic areas and fibrinoid degeneration. Electron microscopic study of the control placentas showed a thick layer of syncytiotrophoblast (Sy), numerous microvilli and a thin layer of cytotrophoblast (Cy). PE placenta showed hypertrophy of Cy with atrophy of Sy and scarce microvilli. The trophoblast showed edematous vacuoles and glycogen storage areas. The villous core had congested capillaries, edematous spaces, glycogen storage areas and widespread areas of fibrosis. All the changes in PE placentas were attributed to hypoxia and oxidative stress and reduced utero-placental flow due to abnormal remodeling of the uterine spiral arteries that was aggravated by the thick placental barrier and the presence of edema, fibrosis and glycogen storage areas.

Download Full-text

Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158650 ◽

1990 ◽

Vol 48 (3) ◽

pp. 222-223

Author(s):

T. Shimizu ◽

Y. Muranaka ◽

I. Ohta ◽

N. Honda

Keyword(s):

Clinical Manifestations ◽

Quadriceps Muscle ◽

Honeycomb Structure ◽

Periodic Paralysis ◽

Ultrastructural Changes ◽

Hypokalemic Periodic Paralysis ◽

Electron Microscopic ◽

Tubular Aggregates ◽

Hypokalemic Myopathy ◽

Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

Download Full-text