Electron microscopic observations and X-ray microanalysis of a multinucleated giant cell.

Giant cells and macrophages play important roles in defence and in reparative functions of the body. This paper describes a giant cell and macrophage present in an inflammatory mass in the temporal bone. X-ray microanalysis performed at the ultrastructural level revealed the presence of a very high iron content in the electron dense precipitates observed in both types of cells. The high iron content is probably due to phagocytosed haemosiderin, a breakdown product of free haemoglobin since there was evidence of haemorrhage present in the biological sections. As the tissue was chemically fixed, it also demonstrates that there is still a place for electron probe microanalysis in tissues (including archived specimens) which have undergone chemical fixation.

Validation of an oscillometric electronic sphygmomanometer in an obstetric population.

Use of an automated electronic sphygmomanometer will allow us to minimize the errors inherent in mercury sphygmomanometry. We conducted this validation according to the 1990 protocol of the British Hypertensive Society. We recruited 87 subjects from the antenatal population of Kandang Kerbau Hospital and took three sequential readings using simultaneously both manual and electronic sphygmomanometry. A total of 261 readings from either method were thus collected and the results analyzed to compare the accuracy of electronically read blood pressure with that assessed manually. We found that 89.9% of the electronically read pressures differed from the manually read pressures by 5 mm Hg or less and 98.9% of the electronic readings differed from manual readings by 10 mm Hg or less; only 0.4% of readings had a difference of more than 15 mm Hg. The accuracy of the device was not affected either by the blood pressure or the arm circumference.

Hydroxyl free radicals generated by vanadyl[IV] induce cell blebbing in mitotic human Chang liver cells.

Vanadium has recently been reported to induce interphase and M-phase (mitotic) programmed cell death via the generation of hydroxyl free radicals (OH*). In this paper, the effects of antioxidants on: (a) vanadyl[IV]-generated OH* free radical levels; and (b) cellular glutathione in vanadyl [IV]-treated Chang liver cells were evaluated. The surface morphology of vanadyl-treated mitotic cells was studied by confocal and scanning microscopy. The free radical scavengers zinc chloride, glucose and thiourea reduced the levels of vanadyl-induced OH* free radicals and partially prevented the depletion of cellular glutathione. Concurrent with OH* free radical production, vanadyl-treated telophase cells exhibited excessive cell blebbing and cell shrinkage. The morphological features demonstrated in vanadyl-induced mitotic programmed cell death as a consequence of oxidative stress is novel.

Abdominal hysterectomy: indications and complications.

This retrospective study was conducted to evaluate the indications and complications for non-radical abdominal hysterectomy. Between 1 July 1990 and 30 June 1991, 176 women underwent abdominal hysterectomy in our Department. The indications for hysterectomy, the conservation of ovaries, type of concurrent procedures, choice of incision, choice of fascial closure in midline incisions, use of prophylactic antibiotics and complications of abdominal hysterectomy were analysed. The most common indication was uterine leiomyomata followed by pelvic endometriosis and premalignant disease. Haemorrhage requiring transfusion was the commonest intra-operative complication. Unintended surgical procedures occurred in almost 3% of patients.

Ultrastructural and immunocytochemical studies of macrophages in an excitotoxin induced lesion in the rat brain.

An epidural application of kainic acid (KA) over the cerebral cortex in rat resulted in an extensive lesion in the ipsilateral cerebral cortex. This procedure elicited an accumulation of a large number of macrophages at the site of lesion covering a period of 4 weeks beginning 4 days after the KA application. The macrophages in the centre of lesion were characterized by abundant cytoplasm containing a variable number of lysosomes and phagosomes. Neurons at the same site were depleted during the period examined. They underwent degeneration following the KA treatment. With the monoclonal antibodies OX-42, OX-18 and OX-6, intense immunoreactivity was observed in these cells at the light and electron microscopic levels. Besides these antibodies, the cells were stained positively with the isolectin Griffonia simplicifolia (GSAI-B4). At the periphery of the lesion, many cells bearing the external morphology of microglia were also intensely stained with the GSAI-B4 and the monoclonal antibodies. It was concluded from this study that neuronal degeneration, caused by the excitotoxin KA, induced the accumulation of macrophages which exhibited CR3 receptors (marked by OX-42), MHC I antigen (marked by OX-18) and MHC Ia (marked by OX-6). The expression of these surface antigens may be related to their active phagocytic activity. The reaction with GSAI-B4 indicates the presence of specific lectin receptors on the macrophages which would serve a similar function. The present lectin histochemistry and immunohistochemical studies suggest that macrophages in the centre of the KA-induced lesion were derived from infiltrated monocytes while those at the periphery originated from the activation of local microglial cells.

Degenerative changes of neurons in the superior cervical ganglion following an injection of Ricinus communis agglutinin-60 into the vagus nerve in hamsters.

The present study describes neuronal changes in the superior cervical ganglion of hamsters following injection of Ricinus communis agglutinin-60 (RCA-60) into the ipsilateral vagus nerve in the cervical region. There were no noticeable structural changes in the ganglion 1 day after injection. Between 3 and 15 days after injection, a small number of neurons located in the caudal part of the ganglion underwent degenerative changes including disappearance of rough endoplasmic reticulum and cytoplasmic vacuolation. The structural alterations were most acute 7 days after the injection when some neurons showed signs of total vacuolation and lysis. A second phase of neuronal change occurred after longer survival periods extending from 60 to 120 days after injection. The most striking feature of such neurons was darkening of their dendrites associated with abnormally high density cytoplasm that contained mitochondria with disrupted cristae. As distinct from the early phase in which cell necrosis was observed, there was no evidence of cell death of neurons bearing darkened dendrites. Since examples of exfoliation of the affected dendrites and their phagocytosis by satellite cells were extremely rare, it is postulated that these structural alterations are probably reversible but over an extended period. The significance of the two phases of degenerative change is discussed in connection with the acute and possible chronic effects of the toxic lectin. The present study also confirms the presence of postganglionic sympathetic axons in the cervical vagus nerve.