Analysis of beta-glucocerebrosidase and ceramidase activities in atopic and aged dry skin

To elucidate the mechanisms that are involved in the decrease of ceramide levels in atopic dry skin and in aged skin, we examined both the activities of beta-glucocerebrosidase, which is a major enzyme in ceramide production, and of ceramidase, which is an essential enzyme in ceramide degradation, in the stratum corneum of atopic dry skin and aged skin. The specimens of the stratum corneum of forearm skin were obtained by tape-stripping from 61 healthy volunteers and 23 patients with atopic uninvolved skin. The beta-glucocerebrosidase activity in the stratum corneum extracts was estimated using fluorescent 4-methylumbelliferyl-beta-D-glucopyranoside as the substrate. Ceramidase activity was determined using 14C-palmitoylsphingosine as the substrate. Among the atopic skin samples, neither beta-glucocerebrosidase nor ceramidase activities were different from those of age-matched healthy controls. Nor was the beta-glucocerebrosidase activity deficient in the aged skin samples as compared to that seen in samples from the young, healthy group. In contrast, there was an age-related upregulation in ceramidase activity. The results indicate that the decrease of ceramides in atopic dry skin may not be accompanied by reduced synthesis or by enhanced degradation, each of which is primarily attributable to the above two enzymes, respectively. The pathogenesis of aged dry skin can be explained, at least partially, in terms of elevated ceramidase activity, which results in a disturbance of the lamellar structure of the stratum corneum lipids.

Regional analysis of ceramides within the stratum corneum in relation to seasonal changes

We studied the regional variations and seasonal changes of ceramide quantities in the stratum corneum of human skin. In summer, the total lipid amounts extracted from the stripped stratum corneum were highest in the forehead, followed by the chest and upper back, with the lowest level in the sole of the foot. In winter, while the total lipid distribution followed the same trend as that in summer, the absolute amounts slightly decreased, especially in the forehead and chest, as compared with those found in summer. Ceramide analysis showed that while a higher level was seen in the cubital fossa in summer, the level was highest in the forehead during winter. A seasonal comparison of ceramide mass revealed a slightly increased level in winter compared with summer, at almost all sites tested, except in the cubital fossa and dorsum pedis, reflecting seemingly enhanced keratinization in winter. These findings indicate that in young adults, the mass of ceramide remains steady at similar levels at various skin sites, providing maintenance of a pertinent water reservoir and the barrier function of the stratum corneum, even under different seasonal conditions.

Pathomorphologic findings of lead poisoning in white-fronted geese (Anser albifrons)

Nineteen lead-poisoned white-fronted geese (Anser albifrons), including nine immature birds, were examined pathologically. Subacute lead poisoning due to ingestion of spent lead shots was diagnosed pathologically and confirmed by demonstrating high lead concentration in the liver. The liver lead concentration ranged from 6.9 to 67.7 mg/kg wet weight. The most suggestive gross lesions were mottled bile-stained liver in eight geese and proventricular impaction and/or the presence of lead pellets in the gizzard. Histologic lesions of the liver consisted of Kupffer cell hemosiderosis, large bile plugs in dilated canaliculi, bile pigmentation in hepatocytes, and bile extravasation and associated hepatic necrosis. Seven geese of the remaining 11 birds also had hepatic necrosis in the liver, the greenish discoloration of which was obscure macroscopically. The liver discoloration was considered a jaundice due to both rapid overproduction of bile from increased breakdown of erythrocytes and intrahepatic impaired excretion of bile. The severity of lesions was not correlated to the liver lead concentrations. All examined geese had hemosiderosis of mononuclear phagocytic system cells in the spleen and hypoplasia or edema of the bone marrow with increased numbers of polychromatic erythroblasts. These prominent changes probably resulted from excess breakdown of erythrocytes, hypercholia followed by intrahepatic cholestasis, and disrupted erythropoiesis in bone marrow caused by lead.

Erythrocyte ALA-d activity in experimentally lead-poisoned ducks and its change during treatment with disodium calcium EDTA

To determine useful procedures for the diagnosis and prognosis of lead poisoning in waterfowl caused by ingestion of lead pellets, erythrocyte delta-aminolevulinic acid dehydratase (ALA-d) was investigated in experimentally lead-poisoned ducks. A highly positive correlation was observed between the concentration of blood lead and the ALA-d activity ratio (the ratio of activated:non-activated enzyme activity) in those birds given seven lead pellets (3 mm diameter). The ALA-d activity ratio rapidly increased after the administration of lead pellets, but began to fall immediately after the initiation of disodium calcium ethylenediamine tetra-acetate (CaEDTA) therapy which resulted in a rapid decrease in the concentration of lead in the blood of these birds. In contrast, the ALA-d activity remained inhibited even after blood lead levels began to decrease following treatment. These results demonstrated that the ALA-d activity ratio is a very useful and sensitive indicator for the diagnosis and evaluation of therapeutic effects after lead poisoning in waterfowl.

A survey of lead poisoning in wild waterfowl in Japan

Ingested shotgun pellets were found in 13 of 56 hunter-killed wild waterfowl between October and December 1991 from two hunting grounds in Japan. Four of 33 other waterfowl found dead in lightly hunted areas between January 1991 and March 1992 were diagnosed as having lead poisoning. We propose that lead poisoning maybe a threat to waterfowl in Japan.

Treatment of lead poisoning in wild geese

Twenty-seven wild geese (Anser albifrons) suffering from lead poisoning caused by ingestion of lead shot were treated with disodium calcium ethylenediaminetetraacetate. The concentration of lead in blood ranged from 0.4 to 23.0 micrograms/ml, with a mean concentration of 5.6 micrograms/ml. In 22 of the birds, 1 to 48 lead pellets (mean, 10.5 pellets/bird) were seen on radiographs of their gizzards. Eleven of 27 birds recovered 3 to 8 weeks after the initiation of treatment. In the birds that recovered, the lead pellets were rapidly eroded as the birds recovered their appetites in response to treatment, and disappeared radiographically between treatment days 17 and 52. The birds that did not survive died within 4 weeks, despite decreased concentrations of lead in blood. Of these 16 birds, 15 had radiographic evidence of impaction of the proventriculus at the first examination and no evidence of resolution of the impaction at the time of death. In contrast, only 2 of the 11 geese that recovered had impaction of the proventriculus at the time of admission. Thus, the condition of the proventriculus seems to be the first consideration to evaluate in the prognosis of lead poisoning in geese.

Pathological study of lead poisoning in whooper swans (Cygnus cygnus) in Japan

During spring 1989, thirty-three whooper swans (Cygnus cygnus) died at Lake Miyajima in Hokkaido, Japan; 15 were examined. The birds were diagnosed as having subacute lead poisoning due to ingestion of spent lead shot. The main gross findings were bile-stained liver, edematous or gelatinous bone marrow, bile-stained lining with hyperkeratosis and lead pellets in the gizzard, and proventricular impaction. Histopathologically, there was lead-hemolytic jaundice of the liver, hemosiderosis in the liver and spleen, and hypoplasia of the bone marrow with increased numbers of polychromatic erythroblasts. Acid-fast intranuclear inclusion bodies were seen in kidneys of seven swans. Under electron microscopy, inclusion bodies had frayed contours and consisted of high-electron-dense fine granules. The lead concentration of the liver ranged from 5.5 to 44.3 mg/kg wet weight. It was suggested that these changes resulted from excess breakdown of erythrocytes, inhibition of heme synthesis, and impaired erythropoiesis caused by lead shot.

Decreased level of ceramides in stratum corneum of atopic dermatitis: an etiologic factor in atopic dry skin?

Stratum corneum lipids are an important determinant for both water-retention function and permeability-barrier function in the stratum corneum. However, their major constituent, ceramides, have not been analyzed in detail in skin diseases such as atopic dermatitis that show defective water-retention and permeability-barrier function. In an attempt to assess the quantity of ceramides per unit mass of the stratum corneum in atopic dermatitis, stratum corneum sheet was removed from the forearm skin by stripping with cyanoacrylate resin and placed in hexane/ethanol extraction to yield stratum corneum lipids. The stratum corneum was dispersed by solubilization of cyanoacrylate resin with dimethylformamide, and after membrane filtration, the weight of the stratum corneum mass was measured. The ceramides were quantified by thin-layer chromatography and evaluated as microgram/mg stratum corneum. In the forearm skin of healthy individuals (n = 65), the total ceramide content significantly declined with increasing age. In atopic dermatitis (n = 32-35), there was a marked reduction in the amount of ceramides in the lesional forearm skin compared with those of healthy individuals of the same age. Interestingly, the non-lesional skin also exhibited a similar and significant decrease of ceramides. Among six ceramide fractions, ceramide 1 was most significantly reduced in both lesional and non-lesional skin. These findings suggest that an insufficiency of ceramides in the stratum corneum is an etiologic factor in atopic dry skin.

Recovery of the contact site A glycoprotein of Dictyostelium discoideum from sodium dodecyl sulfate-polyacrylamide gel and characteristics of monoclonal antibodies against the recovered protein

Monoclonal antibodies were produced against a cell-cell adhesion (contact site A) glycoprotein of Dictyostelium discoideum, isolated by preparative gel electrophoresis. The glycoprotein was recovered by electroelution from a polyacrylamide gel strip and used for the production of monoclonal antibodies. Four of the five antibodies obtained bound specifically to the protein moiety of the contact site A glycoprotein. The specificities of the antibodies were in striking contrast to those of antibodies raised against the contact site A glycoprotein purified by Triton X-114 phase separation and DEAE chromatography. The majority of the latter antibodies recognized the carbohydrate moiety of the contact site A glycoprotein and cross-reacted heavily with other membrane glycoproteins.

Cockayne syndrome: report of two siblings and review of literature in Japan

Typical Cockayne syndrome was seen in a boy and his younger sister and these two cases are reported here, and reported cases of the syndrome in Japan are summarized. Both cases (an 11-year-old boy and a 7-year-old girl) had dwarfism, a senile face, retinitis pigmentosa, photosensitivity, and mental retardation. Calcium deposition in the basal ganglia was seen by CT scan. In both cases nerve conduction velocities were reduced suggesting peripheral neuropathy, but segmental demyelination on sural nerve biopsy was not demonstrated. Twenty seven cases of the syndrome has now been reported in Japan in 21 families (including the above two cases), consisting of 14 males and 12 females (the sex of one case was unknown): consanguineous marriage was confirmed in 14 families. Eleven cases in five families were siblings. The estimated ages of onset were from 1 month to 3 years, and in most cases photosensitivity was the initial symptom. Clinical manifestations were mental retardation in 25 cases (93%), dwarfism in 24 cases (89%), photosensitivity in 23 cases (85%), articular contracture in 22 cases (81%), sunken eyes in 20 cases (74%), retinitis pigmentosa in 17 cases (63%), deafness in 16 cases (59%), and intracranial calcification in 14 cases (51%). Intracranial calcification will be more often detected in future following the development of CT scanning.