The barley Mlo gene: a novel control element of plant pathogen resistance

Mutation-induced recessive alleles (mlo) of the barley Mlo locus confer a leaf lesion phenotype and broad spectrum resistance to the fungal pathogen, Erysiphe graminis f. sp. hordei. The gene has been isolated using a positional cloning approach. Analysis of 11 mutagen-induced mlo alleles revealed mutations leading in each case to alterations of the deduced Mlo wild-type amino acid sequence. Susceptible intragenic recombinants, isolated from mlo heteroallelic crosses, show restored Mlo wild-type sequences. The deduced 60 kDa protein is predicted to be membrane-anchored by at least six membrane-spanning helices. The findings are compatible with a dual negative control function of the Mlo protein in leaf cell death and in the onset of pathogen defense; absence of Mlo primes the responsiveness for the onset of multiple defense functions.

Leg ulcers in Klinefelter's syndrome--further evidence for an involvement of plasminogen activator inhibitor-1

An abnormality in platelet aggregability or fibrinolysis, namely elevated activity of plasminogen activator inhibitor-1 (PAI-1), has been recently documented in patients suffering from Klinefelter's syndrome associated with leg ulceration without underlying venous insufficiency. To determine whether increased PAI-1 activity is a general feature of Klinefelter's syndrome, or more specifically associated with leg ulceration, we investigated PAI-1 influencing parameters and PAI-1 activity in two groups of patients: (i) Klinefelter patients suffering from leg ulceration (n = 7); and (ii) Klinefelter patients without leg ulceration (n = 6). On analysing PAI-1 influencing parameters such as age, body mass index, triglycerides, C-reactive protein, testosterone, smoking behaviour, the presence of diabetes mellitus, and arterial hypertension, respectively, we found no statistically significant differences between the two groups. However, PAI-1 activity in group 1 was highly significantly elevated compared with that in group two patients (P < 0.005). We conclude that (i) PAI-1 activity is not elevated in Klinefelter's syndrome in general; (ii) elevation of PAI-1 activity in patients suffering from Klinefelter's syndrome does not appear to be secondary to PAI-1 influencing parameters; and (iii) elevation of PAI-1 activity may play a crucial role in the pathogenesis of leg ulceration in Klinefelter's syndrome. Therefore, a therapy for leg ulceration in Klinefelter's syndrome that aims to return the elevated PAI-1 activity to normal should be explored.

Immunohistochemical characterization of the 'intimal proliferation' phenomenon in Sneddon's syndrome and essential thrombocythaemia

Cellular changes were immunocytochemically characterized in skin vessels of five patients with idiopathic generalized racemose livedo (Sneddon's syndrome), and one patient with localized racemose livedo associated with essential thrombocythaemia. Antibodies against alpha-smooth muscle-actin, tropomyosin, desmin, vimentin, factor VIII-related antigen, human endothelial cells (CD31), human macrophages (CD68), and HLA-DR positive cells (CR3/43) were used. Conventional light microscopy showed, in all cases, intimal thickening of ascending arteries and arterioles as a result of an accumulation of cells and extracellular hyalinized material. None of the specimens showed infiltration with polymorphonuclear leucocytes or macrophages. The cells in the region of the intimal hyperplasia showed intense positive immunostaining for alpha-smooth muscle actin and tropomyosin. Staining for the intermediate filament desmin was localized to the resident smooth muscle cells of the media, whereas staining for vimentin was found in all types of cells in both the intima and media. Positive immunostaining for factor VIII-related antigen and CD31 was strictly confined to the endothelial cells lining the narrowed lumina of the vessels. No positive staining with either antibody was observed in totally occluded vessels. Cells in the subintimal space did not show reactivity for CD68 in any of the specimens, but two cases showed solitary cells with positive staining for HLA-DR in this region. There were no differences in staining pattern between Sneddon's syndrome and essential thrombocythaemia with any of the antibodies. Our results support the assumption that the 'intimal proliferation' in both diseases is caused by colonization of the subendothelial space with contractile cells of possible smooth muscle origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Juxta-articular fibrotic nodules in Borrelia infection--ultrastructural details of therapy-induced regression

Juxta-articular fibrotic nodules in chronic Borrelia burgdorferi infection commonly regress rapidly under antibiotic therapy. They may therefore serve as a good in vivo model for studying the development and regression of cutaneous fibrotic processes. As shown in a typical case of acrodermatitis chronica atrophicans, this spirochete-induced fibrosis in the upper subcutis of the elbow region is histologically characterized by broad hyalinized collagen tracts interspersed with prominent perivascular lymphocytes and plasma cells. These immune cells vanish completely after 5 days of antibiotic treatment, while fibroblasts discharge matrix vesicles and form elastic fibres.

Disseminated eruptive clear cell acanthoma--a case report with review of the literature

Clear cell acanthoma (CCA) is a benign epidermal tumour with distinctive and uniform clinical and histological features. Although solitary lesions are the rule, some cases of multiple CCA, rarely with more than 10 lesions, have been previously reported. Only 22 cases of multiple CCA have been described in the English literature to date. A healthy 32-year-old woman is reported, with approximately 400 asymptomatic rounded papules, on the upper and lower extremities. Multiple skin biopsies showed the typical histological pictures of CCA. This case appears unusual because of the presence of numerous lesions scattered on the upper and lower extremities. For this reason it could be classified as disseminated eruptive CCA.

UV-induced colloid milium

A 39-year-old woman is reported who developed numerous confluent yellowish semitranslucent papules of the face over 8 months. The patient habitually exposed herself to UVA-radiation twice a week for 7 years for aesthetic reasons. Histological, histochemical and immunohistochemical examinations were consistent with the diagnosis of adult colloid milium. A review of the literature is discussed. This case emphasizes the close relationship between long-term sun exposure, solar elastosis and adult colloid milium.

Cutaneous fibroses induced by Borrelia burgdorferi

Three cases of chronic infection with Borrelia burgdorferi are described. The patients presented with nodular or discoid fibrosis, partly in conjunction with acrodermatitis chronica atrophicans (ACA). Juxta-articular fibrotic nodules may develop within a few months of the onset of ACA. Nodular, discoid morphoea-like, and widespread cutaneous fibroses in chronic Borrelia infection may be provoked by trauma, surgery or electromagnetic radiation. They respond well to antibiotic therapy. These lesions offer an in vivo model for studying the evolution of immunologically induced fibrosis.

The mlo resistance alleles to powdery mildew infection in barley trigger a developmentally controlled defence mimic phenotype

Recessive mlo resistance alleles of the Mlo locus in barley control a non race-specific resistance response to infection by the obligate biotrophic fungus Erysiphe graminis f.sp. hordei. All the mlo alleles analysed stop fungal growth at the same developmental stage within a subcellularly restricted, highly localized cell wall apposition directly beneath the site of abortive fungal penetration. We report that near-isogenic lines carrying the alleles mlo1, mlo3 or mlo5 undergo dramatic spontaneous formation of cell wall appositions, not only in the absence of the fungal pathogen but also in sterile grown plants. A comparative study of spontaneous and infection-triggered cell wall appositions reveals a high degree of similarity with respect to structure, chemical composition and distinct localization within plant tissue. We show that the rate of spontaneous apposition formation is dependent on the genetic background of the plant and that its onset is under developmental control. Furthermore, spontaneous formation of wall appositions is specifically triggered by mlo alleles, since it is unaffected in the presence of the race-specific resistance allele Mlg. We propose a model for the function of the Mlo locus that suggests that both Mlo and mlo alleles control qualitatively the same apposition-based resistance mechanism, which, in the presence of the wild-type Mlo allele, is merely less efficient to provide protection against the currently common races of E. graminis f.sp. hordei.

[Congenital poikiloderma syndrome with early childhood blister formation (Brain syndrome) and unusual associated neurologic symptoms]

We report on an 8-year-old girl with manifestations of congenital poikiloderma during her first year of life. Macroscopically, there was reticular teleangiectasia on cheeks and thighs, generalized de- and hyperpigmentation, dry skin with pityriasiform scaling and milia as a result of former blister formation. Histologically and ultrastructurally cytoid bodies, probably of keratinocyte origin, were observed. Associated findings were leucocytopenia, hyperlipoproteinaemia, spastic ataxia and lack of teeth. There is consanguinity in the family, but 3 sisters, the parents and the ancestors were completely healthy. Because of transient blister formation on the face, upper arms and elbows we would like to classify our case as Brain syndrome.

[HTLV-I infection: ungual T-cell lymphoma as a primary manifestation]

A 34-year-old woman presented with leathery thickening and haemorrhagic lesions of several finger- and toe-nails as first symptoms of an HTLV-I infection. Histology resembled that found in mycosis fungoides. Later signs of T cell deficiency (e.g. Pneumocystis carinii pneumonia) developed. An erythemato-papular exanthema representing T cell lymphoma with Pautrier's abscesses preceded her death 1 year later. The detection of HTLV-I antibodies helped to establish the diagnosis following initial confusion owing to elevation of the T-helper cells and the CD4/CD8 ratio.

[Pampiniform livedo--an acute cardinal symptom of a cutaneous cholesterol embolism]

Acute, painful, persisting, pampiniform and asymmetrical skin discolorations over the legs occurred after retrograde femoral artery catheterization in three patients suspected of having renal artery stenosis. The cause was found histologically to be embolization of cholesterol crystals to the arterioles of the corium-subcutis. Under treatment with acetylsalicylic acid the painful cutaneous changes gradually regressed. The possibility of cholesterol crystal emboli from atheromatous plaques in the aorta should be considered if the described skin changes occur, especially in the legs and with normal arterial pulsations. Proof lies in the histological picture of slit-like spaces in the arteriolar vessels at the corium-subcutis juncture, previously occupied by cholesterol crystals dissolved during fixation, and surrounding inflammatory changes with vessel wall thickening.

[The Kyrle disease entity and its therapeutic modification by acitretin (etretin)]

We report on a 50-year-old woman having suffered from atypically located Kyrle's disease for 2 years. Especially the palmoplantar areas were affected by keratotic erythematous papules showing the typical histologic picture of Kyrle's disease. Treatment with acitretin (initial dose 30 mg/day) resulted in almost complete remission after 6 months. A concomitant lichen nitidus remained unchanged.

Tumor necrosis factor is a terminal mediator in galactosamine/endotoxin-induced hepatitis in mice

Intravenous injection of murine recombinant tumor necrosis factor alpha(TNF-alpha) to male NMRI albino mice in doses greater than 4 micrograms/kg (specific activity 4 x 10(7) U/mg) resulted in a fulminant hepatitis when animals had been sensitized 1 hr before by intraperitoneal administration of 700 mg/kg galactosamine. Liver injury was assessed by measurement of serum transaminases as well as sorbitol dehydrogenase activity 8 hr after administration of TNF-alpha. Pretreatment with either galactosamine or 40 micrograms/kg TNF-alpha alone did not cause hepatitis. Pretreatment of galactosamine/TNF-alpha-injured mice with 800 mg/kg uridine or with 6 mg/kg calmidazolium fully protected the animals, while administration of either verapamil or nifedipine (100 mg/kg, respectively) had no significant effect. The following inhibitors of generation or action of leukotriene D4, which were previously shown to block galactosamine/endotoxin-induced hepatitis in mice, failed to protect against galactosamine/TNF-alpha-induced intoxication: 200 micrograms/kg dexamethasone, 174 mg/kg BW 755 C or 13 x 10 mg/kg FPL 55712. In addition, unlike in the galactosamine/endotoxin model no prevention was achieved by pretreatment of galactosamine/TNF-alpha-injured animals with the following substances blocking the development of an ischemia/reperfusion syndrome: 2 x 100 mg/kg allopurinol, 3.3 x 10(4) U/kg superoxide dismutase, 10(6) U/kg catalase or 10 micrograms/kg iloprost. We conclude from our results that tumor necrosis factor alpha is likely to act as a final mediator of endotoxin action in a sequence of events which includes formation of leukotriene D4 and reactive oxygen species.

[Arachnoid cyst of the 3d ventricle: report of 2 cases]

In 1985 and 1986 the Department of Neurosurgery of the University of Berlin treated two cases of arachnoid cysts of third ventricle, both of which were successfully dealt with surgically. They are reported in this paper. Arachnoid cysts from ventricular system and cisterns are rare. Up to now 46 cases have been reported in the specialized literature. The computerized tomography and magnetic resonance make diagnosis easier, as shown through the cases reported.

[Symptomatic livedo racemosa in cholesterol embolism with occlusion of the arterioles in the area of the corium-subcutis]

We report on a 70-year-old woman suffering from diabetes mellitus dependent on insulin and associated with malignant hypertension. Following heart catheter examination for the dilatation of the renal arteries, she developed acute, painful, persistent livedo racemosa of the buttocks and the lower extremities. Histological investigation revealed embolism of cholesterol crystals in arterioles of the corium-subcutis region. On the basis of the cases described in the literature so far, we discuss the clinical spectrum of cutaneous cholesterol embolism.

Fatal outcome in a metatypical, giant, "horrifying" basal cell carcinoma

Mutilating, horrifying, aggressive basal cell carcinoma (BCC) is a rare cutaneous neoplasm. We report a case of mutilating BCC of the face and its peculiar histologic features. The primary lesion, before therapy, demonstrated typical BCC in association with lobules of metatypical cells. The recurrent BCC, after radiation therapy, had a metatypical pattern. We believe that the metatypical BCC is a potentially aggressive lesion. It is essential for this tumor to be recognized early and treated surgically.

[Simultaneous study of ocular vascular reactions of the anterior and posterior segments following clonidine and propranolol in normotensive and hypertensive experimental animals]

The influence of clonidine and propranolol on the vessels of the anterior segment and of the fundus, as well as on mean arterial pressure and heart rate, was investigated in normal rabbits, minipigs, and minipigs with experimentally induced hypertension. The vessel reactions were monitored by photography or fluorescein angiography. Following injection of clonidine, constrictions of episcleral and conjunctival vessels occurred in all the animals, but the fundus vessels of the rabbits were not affected. Difficulties were encountered in assessing the condition of the iris vessels. In minipigs, after administering 6-20 micrograms/kg, an average delay of 2 seconds in the inflow into the retinal vessels was recorded, due possibly to a (transitory?) vessel constriction upstream. Mean arterial pressure increased initially in all animals, but to a different extent in the two species. There was less uniformity as regards heart rate. The vessel reactions of the two species to propranolol were different: in rabbits, a reaction was only observed after administering 2.46 mg/kg bodyweight in episcleral and conjunctival vessels, though not in fundus vessels. Minipigs were given doses of 0.16, 0.5, and 0.8 mg/kg; after 0.5 mg/kg a vessel constriction took place in the episclera and the conjunctiva, becoming manifest after 20 minutes and attaining a maximum after 60 minutes. However, there appeared to be no reaction in the fundus vessels. After an abrupt decrease in mean arterial pressure, both this and the heart rate showed an almost identically slow decrease until the 50th minute, followed by a slight increase up to the 60th minute. The comparison of the circulation parameters reveals some interesting parallels, though also some contrasts. The mechanisms of action and characteristics of these two substances are discussed.

Prognostic indicators in multiple sclerosis

The influence of sex, age at onset, course of the disease and initial symptomatology on the mortality of patients with multiple sclerosis is analysed. A sample of 1926 patients was followed up prospectively over 4.9 years. Both, the mortality ratio (number of observed to expected deaths) and the excess death rate are calculated. Whereas the mortality ratio as a parameter of overall mortality is influenced by a variety of factors, such as age and sex; the excess death rate represents the number of extra deaths per 1000 exposed to risk in an indicated year and is, therefore, a parameter of the mortality which is attributed to MS. The excess death rate was comparable for the sexes, it was slightly higher for patients with a higher age at onset and it was clearly higher for the progressive course. Patients with initial diplopia and sensory signs and symptoms had the lowest excess death rate, whereas patients with pareses, cerebral and sphincter disturbances at onset showed the highest excess death rate.

[Simultaneous photography or angiography of anterior and posterior eye segments in experimental animals]

Simultaneous photographic or angiographic studies of the anterior and posterior segments requires a considerable reduction in the respective parts of the negatives; this can be avoided by simultaneous study of the one segment ipsilaterally and the other contralaterally (this can also be performed vice versa). Differences and common properties of the eyes of rabbits and miniature pigs and the human eye are described. Apart from the monkey eye, the pig eye is most readily comparable with the human eye as regards vasotopographic and vasomorphologic conditions. In addition, the courses of angiographies in the eyes of experimental animals were observed; measurements of fluorescein inflow and circulation times in the anterior and posterior segments in miniature pigs are presented. These were subjected to significance tests: only the difference in the inflow and outflow of the dye in retinal vessels was found to be statistically highly significant. The difference in inflow between choroidal and retinal vessels was not significant, though this may have been due to an error of measurement. The techniques and measurements described represent the basis of observation in miniature pigs with experimentally induced hypertension.

[Neuromyotonia syndrome (author's transl)]

In addition to the 19 cases of neuromytonia syndrome previously published, one further observation by the author is presented. The symptoms for neuromyotonia are an involuntary tensing of the musculature with impairment of movement, fasciculation and myokymia as well as specific electromyographic criteria. These symptoms are causes by a functional disturbance in the peripheral nervous system. They can be considerably improved by administering phenytoin and carbamazepine.