Striate palmoplantar keratoderma arising from desmoplakin and desmoglein 1 mutations is associated with contrasting perturbations of desmosomes and the keratin filament network.

BACKGROUND: Several hereditary human diseases are now known to be caused by distinct mutations in genes encoding various desmosome components. Although the effects of some of these mutant genes have been analysed by targeted disruption experiments in mouse models, little is known about the cell and tissue changes in affected human patients. OBJECTIVES: To investigate the effects of heterozygous nonsense mutations in desmoplakin (Dp) and desmoglein (Dsg) 1 which cause the autosomal dominant disorder striate palmoplantar keratoderma (SPPK), focusing on changes in desmosome structure and composition and the associated keratin intermediate filament (KIF) network in palm skin, and in cultured keratinocytes generated from the same site. METHODS: We analysed palm and nonpalm skin sections from four SPPK patients with Dp mutations and one patient with a Dsg1 mutation with respect to tissue and subcellular morphologies, and correlated the in vivo and in vitro findings. RESULTS: Using electron microscopy, we found abnormalities of desmosomes and cell-cell adhesion in the suprabasal layers in the epidermis from patients with both Dsg1- and Dp-associated SPPK. These changes were more advanced in skin from patients with Dp mutations. Both Dp and Dsg1 mutations were accompanied by significantly reduced numbers of desmosomes in the suprabasal layers, while decreased desmosome size was evident only in Dsg1-associated SPPK. Confocal microscopy analysis showed marked differences in the expression of keratins and of desmosome components, both between the two types of SPPK, and between SPPK and normal skin. The expression of keratins K5, K14 and K10 was reduced in Dsg1-associated SPPK skin, whereas perinuclear aggregation of keratin filaments was more evident in Dp-associated SPPK. In both types of SPPK upregulation of K16 was pronounced and involucrin labelling was abnormal. CONCLUSIONS: Mutations in Dp and Dsg1 genes causing SPPK may be associated with perturbations in epidermal differentiation accompanied by a marked disruption of several components of the epidermal scaffold including desmosomes and the KIF network.

Prognostic importance of DNA flow cytometry in non-Hodgkin's lymphomas.

Eighty one cases of non-Hodgkin's lymphoma were examined by DNA flow cytometry, using fixed embedded histological tissue. The frequency of detection of DNA aneuploidy and the values for S phase fractions depended on the histological subtype and grade of lymphoma. Twenty two of the patients with low grade centroblastic/centrocytic non-Hodgkin's lymphoma had repeat biopsies. Eleven of these patients remained histologically and cytometrically stable, but the remaining eleven transformed into high grade non-Hodgkin's lymphoma. The mean value for the S phase fraction in the initial biopsy specimens from patients which transformed was higher than that for patients whose lymphomas remained stable (p less than 0.001). It is proposed that estimates of S phase fraction prospectively identify patients with low grade non-Hodgkin's lymphoma at risk from transformation.

Reactions of the tumour bed to lethally irradiated tumour cells, and the Révész effect.

Subdermal inoculation of the foot of the rat with lethally irradiated (LI) Walker tumour (W256) cells, mixed with viable (V) W256 cells, decreased the latent period for initiation of allogeneic tumour growth without significantly affecting its rate. This Révész effect decreased with increase in the number of inoculated V cells, and with decrease in age of recipient. LI cells of a different (Y-P388) rat tumour exerted a Révész effect, even in recipients which had been immunized with LI (Y-P388) tumour cells. Local pre-irradiation of the site of inoculation of V cells decreased both the latent period and rate of tumour growth. It acted independently of a Révész effect, and the decrease in tumour growth rate was partly due to emigration of V cells from the inoculum, producing metastases. LI, but not heat-killed cells, induced prolonged swelling of the tumour bed in unimmunized and tumour-immunized rats, which, unlike inflammatory swelling, was inhibited by pre-irradiation of the foot. It is postulated that the Révész effect is due to enhancement of survival of V cells by trophic substances which are principally elaborated by LI (AND V) cells, but also by the tumour bed, due to innate growth and trophic reactions of its tissues to the presence of tumour cells.

The significance of free blood in liquid and solid tumours.

Impregnation of the vasculature with ink was used to study microvascular changes induced in rats by liquid (ascites) and solid growth of W256 and Y-P388 tumour cells. Ascites fluid produced by both tumours was heavily blood-stained; the deep red colour of solid tumour deposits was similarly due to the presence of free blood. In both types of tumour growth this free blood was due to diapedesis of erythrocytes through tips of capillary sprouts which grow when neovascularization (angiogenesis) occurs in response to any suitable (non-neoplastic or neoplastic) stimulus. Ascites growth of these tumours induced profuse sprouting from the peritoneal capillaries; this sprouting, together with the "bleeding" it caused, were inhibited by local pre-irradiation of the peritoneal vasculature with X-rays before intraperitoneal inoculation of rats with the tumours. Similar angiogenesis with bleeding did not occur following inoculation with an allogeneic tumour in rats which had been previously immunized against the tumour. LI tumour cells (tumour cells lethally irradiated in vitro to destroy their proliferative integrity, but which remain metabolically active) also induced sprouts to grow in close proximity to the implanted LI cells, but heat-killed tumour cells caused no sprouting. The nature and significance of neovascularization of tumours and their so-called "haemorrhagic" growth are discussed.

Rapid and accurate measurement of growth of solid tumours and changes in the tumour bed in the rat by the technique of volumetric displacement.

An apparatus which has been widely used in rats for measuring swelling of the foot induced locally by inflammatory agents has been adapted to measure rapidly, accurately and objectively, the growth of tumour cells transplanted to the foot, and the reactions of the normal tissues (tumour bed) to tumour growth. General features on the apparatus and the techniques used are described. Examples are provided of preliminary measurements made of normal growth of the foot, reactions of the foot to two injurious agents (histamine and Corynebacterium parvum) and of growth of allogeneic (W256) tumour cells.

Innate and drug-induced resistance to acute lung damage caused in rats by alpha-naphthyl thiourea (ANTU) and related compounds.

During the 3rd and 4th weeks of life rats were highly resistant to the toxic effects of alpha-naphthyl thiourea (ANTU) and of thiourea and its derivatives but toxicity developed rapidly during the following 2 weeks. Marked resistance to lung damage by toxic thioureas could be induced in older, mature rats by pretreatment with the toxic agent itself (tachyphylaxis), with other toxic and non-toxic antithyroid drugs or with iodine or iodide--even if the rats were pretreated at an early age before susceptibility to the agent developed. ANTU-tachyphylaxis was dose-dependent. Total thyroidectomy did not affect either lung damage induced by ANTU or the resistance due to tachyphylaxis or to pretreatment with iodide or the antithyroid drugs thiourea, 1-ethyl-1-phenyl thiourea or propyl thiouracil. Neither total nor medullary adrenalectomy affected ANTU toxicity. Marked resistance to ANTU-induced lung damage was induced in rats by pretreatment with either an activator (3-4 benzypyrene) or an inhibitor (SKF 525-A) of drug-metabolizine mixed-function microsomal enzyme systems; the inhibitor, sodium phenobarbitone, had no significant effect on toxicity. The sulphydryl compound, AET, induced marked resistance to ANTU; cysteine was less effective. Neither autonomic blockade with nicotine and atropine nor actinomycin D had significant effects on toxicity to ANTU. The acute pulmonary oedema induced in rats by high pressure oxygen, chemical convulsants, pressor agents and ammonium sulphate differed in many respects from that induced by toxic thioureas; it was typically haemorrhagic in nature, did not result in significant pleural effusion, did not exhibit tachyphylaxis, and was not influenced by pretreatment with iodide or derivatives of thiourea.

Lowering of innate resistance of the lungs to the growth of blood-borne cancer cells in states of topical and systemic stress.

The survival and clonogenic growth (measured in terms of colony forming efficiency (CFE) of intravenously injected (i.v.) Walker (W256) tumour cells in the lungs of rats was greatly enhanced by states of topical and systemic stress induced by the intraperitoneal (i.p.) injection of rats with a single dose of 10(-5)-10(-3) mmol g-1 body weight of adrenaline and other beta-adrenergic agonists, inflammatory agents (including local x-irradiation), convulsive seizures, "tumbling" or physical restraint. Lowering of innate resistance of the host to growth of seeded tumour cells induced by states of topical and systemic stress, and by the addition of an excess of lethally irradiated (LI) tumour cells to i.v. injected intact tumour cells, were all potentiated by treatment of rats with aminophylline, an inhibitor of cyclic AMP phosphodiesterase. Enhancement of tumour growth by systemic stress was inhibited by bilateral total or medullary adrenalectomy and is attributed to the release and actions of endogenous adreno-medullary hormones. Alpha-adrenergic and most non-adrenergic agents administered in maximum tolerated doses did not significantly affect host resistance to tumour growth in the lungs. These findings, correlated with measurements of cyclic AMP in the lungs of normal and stressed rats, suggest that changes in the resistance of the host to tumour growth involve changes in cyclic nucleotide metabolism in the target tissues (tumour bed); possible mechanisms of action of cyclic nucleotides in this respect are discussed.