Uneven hepatic copper distribution in Wilson's disease

BACKGROUND/AIMS

Determination of hepatic copper concentration is important in the diagnosis of Wilson's disease. We studied copper distribution in the cirrhotic liver of a patient who died of Wilson's disease.

METHODS

A liver slice extending from the left to the right lobe was divided into 38 samples. Each sample was analyzed for copper content by Induced Coupled Plasma Atomic Emission Spectroscopy.

RESULTS

The mean copper concentration in the liver was 1370 micrograms/g dt. A striking variability, up to 2-3-fold, in copper levels was observed between the samples: the copper concentration ranged from 880 to 2100 micrograms/g dt, with significant differences even between adjacent samples. Lobar differences were also observed, with a tendency of the right lobe to accumulate more copper than the left lobe. Histochemical analyses confirmed the uneven distribution of copper even at the acinar level. Copper was mainly stored in periportal hepatocytes (zone 1) and at the periphery of the regenerating nodules. Moreover, we observed some nodules with the majority of hepatocytes full of copper granules, adjacent to areas of parenchyma negative for copper stains.

CONCLUSIONS

Our data show that: 1) copper is unevenly distributed in Wilson's disease in the cirrhotic stage; 2) a lobar pattern of copper distribution is evident in this case, characterized by a higher copper concentration in the right lobe; 3) the observed lobar pattern is different from that described in the newborn liver, characterized by a higher copper content in the left compartment of the liver; 4) copper content determined in a small liver sample cannot be considered as absolutely representative of the mean hepatic copper concentration. From a practical point of view, our data show that sampling variability deserves more consideration in the diagnosis and in the monitoring of Wilson's disease. The use of hepatic copper concentration in monitoring the efficacy of the copper-chelating therapy may be unreliable, particularly in the cirrhotic stage, because of the patchy distribution of copper, as demonstrated in this study.

Morphological features of different regions in frog crista ampullaris (Rana esculenta)

The cellular organization of different regions of the crista epithelium from the frog posterior semicircular canal was studied by light, transmission and scanning microscopy. The sensory epithelium consists of hair cells surrounded by supporting cells and basal cells located close to the basement membrane. Three types of hair cells, namely club-like, cylindrical and pear-like cells differentially distributed along the crista could be recognized on the basis of their shape. Club-like cells are located only in the peripheral regions, cylindrical cells both in the central and in the peripheral regions, and pear-like cells appear segregated into the intermediate regions. Sensory cells of the central region are characterized by a ciliary apparatus consisting of stereocilia usually shorter--and in some cases less numerous--than those of cells of the other regions. The presence of large evaginations of the apical membrane of hair cells and of several vesicles of microexocytosis demonstrates that receptor cells have a considerable secretory activity. This secretory activity is also proven by the presence in the supranuclear region of hair cells of numerous Golgi complexes. Moreover, the presence of two kinds of Golgi complexes, one constituted by dilated cisternae containing a moderately electron-dense material and the other made up of flattened electron-transparent cisternae, suggests a diversified secretion of material by the hair cells. This heterogeneous material may provide substances important for cupula formation and the composition of the endolymph.

Evaluation of new small barium alginate microcapsules

Microencapsulation of islets of Langerhans has been proposed in order to prevent immune rejection and possible recurrence of autoimmune disease. This study introduces a fast simple one-step microencapsulation procedure which allows the production of small sized barium-alginate beads. The volume of the microcapsules produced was approximately that of the encapsulated islets. Consequently, the insulin kinetics and the oxygen diffusion were favoured, while the transplanted tissue volume was reduced. Electron microscopy and immunoisolating testing were performed to evaluate the molecular cut-off, the physical and chemical characteristics of these microcapsules. Immunohistochemical staining and perifusion experiments of microencapsulated pancreatic islets showed their viability after the encapsulation procedure as well as in vivo experiments. In fact, microencapsulated porcine islets were implanted intraperitoneally into streptozotocin-diabetic rats. The xenografts reversed the hyperglycemic state and functioned for a period ranging from 9 to 385 days. The low mannuronic acid concentration and the purity grade of the alginate, exerted a combined influence on the capsule biocompatibility as in vivo studies showed.

The intracellular structure of secretory and ductal epithelia of human major salivary glands. A scanning electron microscopic study

The secretory and ductal cells of human salivary glands have been studied at Scanning Electron Microscopy (SEM) by our modification of the Aldehyde-Osmium-DMSO-Osmium (A-ODO) maceration method which enables the analytical study of human bioptical specimens. The most interesting results are those concerning the visualization of the cytoplasmic aspect of intercellular canaliculi of serous cells and of mitochondria of ductal cells. The canaliculi appear as elongated cylindrical structures fenestrated by holes correspohding to the bases of microvilli deprived of the cytoskeleton. Mitochondria of principal cells are longer and more complex than previously reported.

An electron microscopic study of apoptosis induced by cycloheximide in rat liver

A histological and ultrastructural study, coupled with transmission and scanning electron microscopy of the early changes in the liver following a single administration of cycloheximide (CHX), was carried out in male Wistar rats. At the histological level, apoptosis was already present in the liver 2 h after treatment. By scanning electron microscopy, the following sequential changes were observed: brightness and progressive detachment of hepatocytes from neighbouring cells, formation of surface infolds with multiple blebs and, finally, release of several membrane-bounded apoptotic bodies (ABs) in the extracellular space and into the sinusoidal lumen. Three hours after CHX administration, the apoptotic cycle was completed, as shown by the presence of phagocytosed ABs inside the cytoplasm of intact liver cells. Light microscopic examination of the liver 6 h after CHX administration showed ABs mainly located in the cytoplasm of intact hepatocytes and inside activated Kupffer cells. By transmission electron microscopy, it was possible to demonstrate that cells undergoing apoptosis were hepatocytes. At 24 h, the livers of treated animals appeared normal, with no evidence of apoptosis.

Iron concentration and distribution in the newborn liver

Recent observations on a correlation between fetal serum ferritin and gestational age, consistent with an increase in fetal iron stores during pregnancy, led us to study liver iron content in 22 human stillborns, newborns and infants of different gestational and postnatal age. At autopsy, a longitudinal liver slice was subdivided into ten blocks. Each sample was analyzed for iron content by atomic absorption spectroscopy. The mean iron concentration in the studied livers was 21.6 microM/g dry tissue (d.t.). A striking interindividual variability in iron content was observed: the hepatic concentration of the metal ranged from 3.3 to 64.4 microM/g d.t. No correlation was found between the hepatic iron concentration and gestational age or other clinical parameters of the patients studied. Moreover, the total storage iron of the liver did not appear to be correlated with the gestational age. The analysis of iron concentration in ten blocks in each liver revealed an irregular distribution of the metal. Lobar differences were observed, with a tendency of the left lobe to accumulate more iron than the right one. Furthermore, striking differences in iron content were found between adjacent liver samples, ranging in one instance from 4.5 up to 109.0 microM/g of dry tissue. Perls' stain for iron was positive in 7 out of the 22 livers examined, showing an irregular acinar distribution, with preferential periportal localization. Our data show that the newborn liver can be considered an interesting model for the study of iron storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Scanning electron microscopy of chronic hepatitis C. An OsO4 maceration study on human biopsies

A study at the scanning electron microscope (SEM) on the liver changes in chronic hepatitis C was carried out in human needle biopsies from four patients. Intracellular structures were visualized by a novel modification of the OsO4 maceration method that allows to investigate human pathological specimens. At low magnification we observed both sinusoidal and hepatic cells alterations: sinusoids appeared occluded by lymphocytes, hypertrophic Kupffer cells, activated perisinusoidal cells, necrotic material and apoptotic bodies. Some hepatocytes showed ballooning, arrangement in rosettes, and structural changes related to apoptosis: cell rounding, detachment from neighbouring cells, clustering of cytoplasmic organelles and cell fragmentation. We also found periterminal, sinusoidal, and pericellular severe fibrosis, and bile duct damage of moderate degree. At higher magnification, after removing the intracellular matrix, all the intracellular structures appeared normal, except for focal dilatation of smooth endoplasmic reticulum. Our findings clearly demonstrate the usefulness of the OsO4 maceration method for the study of chronic hepatitis and of liver disease in general. Thank to this technique, in fact, SEM becomes a diagnostic tool complementary to light microscopy and transmission electron microscopy (TEM), for its unique ability to give both low magnification panoramic views and detailed high magnification 3D images of cell organelles.

Familial cardiomyopathy, mental retardation and myopathy associated with desmin-type intermediate filaments

The clinical and morphological findings of a familial case affected by mental retardation, severe biventricular hypertrophic cardiomyopathy and vacuolar myopathy are reported. The phenotype of this patient is similar to that described by other authors, in which a lysosomal glycogen storage disease with normal acid maltase levels was suspected. However, in our case the vacuoles were stained by several antibodies directed against various sarcolemmal proteins, such as dystrophin and spectrin, and therefore, were not of lysosomal origin. Some of these vacuoles were clearly derived from the splitting of the fibres and invagination of the extracellular space; autophagic vacuoles were not observed. The accumulation of desmin-type, intermediate filaments was demonstrated on immunocytochemistry both in the skeletal and cardiac muscles. A brother of the propositus was also affected by mental retardation, severe cardiomyopathy and died suddenly at the age of 24 yr. A cardiomyopathy and mental subnormality were also present in other male cousins of the proband, while sudden death occurred in several females relatives, whose intelligence was normal. None of these latter individuals was available for further investigation. This report expands the spectrum of desmin associated myopathy and cardiomyopathy to include a familial condition with associated mental retardation.

Early ultrastructural changes during thioacetamide-induced apoptosis in rat liver

An histological and ultrastructural study of the early changes in the liver following a single administration of thioacetamide (TH), was carried out in male Wistar rats. One hour after treatment, apoptosis was already present in the liver. By electron microscopy, the following sequential changes were observed: progressive detachment of hepatocytes from neighboring cells, formation of surface infolds with multiple blebs and, finally, release of several membrane-bounded apoptotic bodies in the extracellular space and into the sinusoidal lumen. Three hours after TH administration, the apoptotic cycle was almost entirely completed, as shown by the presence of phagocytosed apoptotic bodies inside the cytoplasm of intact liver cells. Our study evidences that TH induces apoptosis of liver cell as early as one hour after its administration. Moreover, our data show that the apoptotic cycle may be completed in 3-4 h. From the morphological point of view, apoptosis induced by TH appears indistinguishable from programmed cell death, occurring during embryogenesis or metamorphosis, and from apoptotic cell death seen during regression of mitogen-induced rat liver hyperplasia.