Investigative & cell pathology最新文献

Pregnancy proteins can be conveniently divided into three groups, the so-called trophoblast-specific, the pregnancy-associated and the foetal proteins. In this review we have attempted to outline the physicochemical properties and clinical value of the pregnancy-specific and pregnancy-associated proteins in the monitoring of feto-placental function and malignant disease. Where possible, we have tried to indicate areas of future development.

Men and mammals (excluding the indigenous mountain species) who are born at high altitude, or who ascend to live there for a long period, have to undergo acclimatization which affects virtually every system in the body. Since chronic hypoxia is the most important adverse factor in the mountain environment, the lung plays a major part in the process and shows many alterations in structure and function. However, we remain ignorant about many aspects of acclimatization of the lung to hypoxia especially at the ultrastructural level with respect to those cells whose normal function is not yet established. An account of what is known is given in this paper.

There are many factors which are responsible for the high incidence of cachexia in human neoplasia. In this review, those considered to be of major importance are discussed. Nutritional disturbances, such as anorexia and malabsorption, are common and nutritional repletion may be beneficial to certain patients. Raised metabolic rate and energy expenditure are also encountered. Tumour cells may act as a nitrogen trap or energy sink, but the significance of these mechanisms in man is questionable. Ectopic hormone production by tumours is well established and a number of tumour-derived substances have been described which interfere with the intermediary metabolism of the host. The significance of these various substances also remains uncertain. Most experimental studies of cancer cachexia have utilized transplantable animal tumour models which bear a poor resemblance to the clinical condition. Development of more suitable models with human tumour xenografts might allow a quicker and better understanding of the aetiologies of human cancer-induced cachexia.

Electron microscopy confirms the unity of Histiocytosis X (HX) by identifying a common marker organelle in all three forms of the disease (acute disseminated HX or Letterer-Siwe disease; chronic disseminated HX or Hand-Schuller-Christian disease; localized HX or eosinophilic granuloma). The marker organelle of HX is also found in normal Langerhans' cells: these mononuclear cells are distinct from macrophages but are similarly concerned in antigen transport. HX may therefore be considered to represent a pathological proliferation of Langerhans' cells. The natural history and the clinical, radiological and pathological features of primary pulmonary HX (eosinophilic granuloma of the lungs) are described, together with the differential diagnoses which must be considered by the histopathologist.

The process of differentiation in keratinocytes of human buccal mucosa is accompanied by a number of specific membrane and cytoplasmic changes. Using simple tissue culture techniques, it has been possible to establish an in vitro model for keratinocyte differentiation which closely resembles the in vivo situation. A multi-layered structure is formed with maturation towards the surface. The superficial cells are characterized by a thickening of the plasma membrane, an increased concentration of tonofilaments, loss of intercellular adhesions and the presence of membrane-coated granules. It is concluded that this represents a suitable in vitro model for the biological and pathological study of both normal and abnormal oral epithelium.

Elevated blood levels of immunoreactive human chorionic gonadotrophin (HCG) have been reported in many patients with non-trophoblastic tumours, but also in various non-malignant conditions. Even normal tissues other than placenta have been shown to produce HCG, such as gonads, gastrointestinal tract, liver, and pituitary. Since HCG is produced, albeit at a low level, by a variety of normal tissues, there is no need to invoke the gene derepression theory to account for 'ectopic' HCG production. However, tumours associated with excess of biologically active HCG as evidenced by endocrinological abnormalities, such as precocious puberty or gynaecomastia, are very rare. We have reviewed the world literature and found 44 such tumours in the lung, adrenal gland, liver, gastrointestinal tract, and genitourinary tract (excluding the gonads). The analysis of their histological pattern shows that they typically contain syncytial giant cells or frankly choriocarcinomatous elements. In this respect they are like germ-cell tumours associated with excess HCG production. The precursor of the HCG-containing cells in 'somatic' tumours is unknown but their functional and morphological similarity to the trophoblast revives the old concept of pathophysiological correspondence between some malignant tumours and invasive trophoblast.