THE CYTOLOGIC DEMONSTRATION OF BETA-GLUCURONIDASE EMPLOYING NAPHTHOL AS-BI GLUCURONIDE AND HEXAZONIUM PARAROSANILIN; A PRELIMINARY REPORT

Immunotoxic effects of exposure to the antifouling copper(I) biocide on target and nontarget bivalve species: a comparative in vitro study between Mytilus galloprovincialis and Ruditapes philippinarum

Edible bivalves constitute an important bioresource from an economic point of view, and studies on their immune responses to environmental pollutants are crucial for both the preservation of biodiversity and economic reasons. The worldwide diffusion of copper(I)-based antifouling paints has increased copper leaching into coastal environments and its potential impact on both target and nontarget organisms. In this study, immunotoxicity assays were carried out with short-term (60 min) cultures of hemocytes from the bivalves Mytilus galloprovincialis-a mussel dominant in the macrofouling community-and Ruditapes philippinarum-a clam dominant in the soft-sediment community-exposed to CuCl to compare the toxic effects on their immune responses. The LC50 values were similar, 40 μM (3.94 mg L-1) for the mussel and 44 μM (4.33 mg L-1) for the clam. In both species, apoptosis occurred after exposure to 1 µM (98.9 μg L-1) CuCl, the concentration able to significantly increase the intracellular Ca2+ content. Biomarkers of cell morphology and motility revealed microfilament disruption, a significant decrease in yeast phagocytosis and lysosome hydrolase (β-glucuronidase) inhibition beginning from 0.5 µM (49.5 μg L-1) CuCl in both the mussel and clam. The same concentration of CuCl affected biomarkers of oxidative stress, as a significant decrease in reduced glutathione content in the cytoplasm and inhibition of mitochondrial cytochrome-c oxidase (COX) were detected in both species. Comparison of the biomarkers showed that clam is more sensitive than the mussel regarding alterations to the lysosomal membrane and reactive oxygen species (ROS) production, which supports the potential harmful effects of antifouling biocides on the survival of nontarget pivotal species in the coastal community.

A first insight into haemocytes of Pinctada imbricata radiata: A morpho-functional characterization

The pearl oyster Pinctada imbricata radiata (Leach, 1814), from the Pacific Ocean, was one of the first species to reach via Suez the Mediterranean, colonizing the eastern basin and recently spreading to the western. The species showed to be able to adapt to a wide range of climatic, hydrological, and ecological conditions. Since 2000 it reached the Strait of Messina, where is now infesting the transitional waters of the oriented natural reserve "Laguna di Capo Peloro." Due to such resistance and adaptation ability, various assays were performed. Haemocyte morpho-functional aspects were evaluated in haemolymph samples fixed with 1% and 2% glutaraldehyde for optical and electron microscopy (TEM). The following assays were carried out: cell characterization using several dyes, detection of intra- and extracellular lipids, the capability of phagocytosis using the yeast Saccharomyces cerevisiae and to produce superoxide anion (O^2- ). Detection of several enzymes, such as acid and alkaline phosphatase, arylsulfatase, chloro-acetylesterase and β-glucuronidase was also assessed. Cell count was demonstrated to be abundant with a mean of 8.263 × 106 mm²  ± 0.935 × 106 (SD). Two main cell populations were noticed: granulocytes and hyalocytes, both competent for phagocytosis, to produce O^2- , and characterized by lipids. Based on the granule analysis, enzymatic activity was also demonstrated. The observations under TEM confirmed all the results obtained. This study supports the hypothesis that P. imbricata radiata can be usefully employed as a model organism in environmental biomonitoring. Moreover, since the species represent potential threats to native species and ecosystems, further insights into its biological adaptations in invaded ecosystems are recommended.

Identification of haemocytes and histological examination of gills of the spiny oyster Spondylus gaederopus (Linnaeus, 1758)

In the framework of investigations aimed to detect new available bioindicators in marine environment, haemolymph cells and ctenidia of the Mediterranean spiny oyster, Spondylus gaederopus, have been investigated. Haemocyte count and characterisation, phagocytosis and superoxide anion production and enzyme activity assays, have been carried out. TEM observations have been performed. After gross anatomy observations, cito-histological determinations have been carried out, especially focused on ctenidia structure and function. Main results concerned the relatively low number of circulating cells, and the rich in granules granulocytes, most of which were lysosomes. Release of lysosomal enzymes was confirmed a shared trait inside bivalves. Glycogen deposits as probable result of conversion of bacteria carbohydrates, have been detected, as well as the occurrence of both acidophilic and basophilic haemocytes. Phagocytosis, both in granulocytes and agranulocytes, has been recorded, together with the production of superoxide anion. Haemocytes were found positive to acid phosphatase, alkaline phosphatase, β-glucuronidase, chloroacetylesterase and arylsulphatase. Ctenidia showed a complex organization, including two demibranch to each ctenidium, two different kinds of lamellae filament and specialized structures as ciliated disks connecting filaments in "eutherorhabdic ctenidia". The occurrence of three different types of mucous cells in the same region of ordinary filaments has been underlined. Such features, suggesting high resistance to environmental stress and disease, allow to consider spiny oysters as promising bioindicators, although deserving of further investigations to evaluate the physiological responses to stress in controlled conditions. Present data, moreover, providing basic information on the biology of S. gaederopus, notably implement the present knowledge on the Mediterranean spiny oysters, whose under-evaluated ecological role should be carefully considered.

First Evidence of In Vitro Effects of C6O4-A Substitute of PFOA-On Haemocytes of the Clam Ruditapes philippinarum

Alternative chemicals to per- and poly-fluoroalkyl substances have recently been introduced in various industrial processes. C6O4 (difluoro{[2,2,4,5-tetrafluoro-5-(trifluoromethoxy)-1,3-dioxolan-4-yl]oxy}acetic acid) is a new surfactant and emulsifier used as a replacement for perfluorooctanoic acid (PFOA). From an ecotoxicological point of view, in vitro assays are useful tools for assessing the negative effects and understanding the mechanisms of action of chemicals at the cellular level. Here, we present the results of an in vitro study in which the effects of C6O4 were evaluated-for the first time-on haemocytes of the clam Ruditapes philippinarum. Cells were exposed to three concentrations of C6O4 (0.05, 0.5, 5 μg/mL) and the effects on haemocyte viability, haemocyte morphology, differential haemocyte count, lysosomal membrane stability, superoxide anion production, acid phosphatase, and β-glucuronidase activities, as well as on the percentage of micronuclei and chromosomal aberrations were evaluated. The results demonstrated that C6O4 significantly affected haemocyte morphology, lysosomal membrane stability, hydrolytic enzyme activity, and superoxide anion production, and promoted chromosomal aberrations. To the best of our knowledge, this is the first study revealing the in vitro effects of C6O4, a substitute for PFOA, on haemocytes from a bivalve species.

Changes in Activity of Selected Lysosomal Enzymes in Peritoneal Macrophages of Renal Failure Patients on Peritoneal Dialysis

Activity of acid phosphatase (AP), beta-glucuronidase (GR), N-acetyl-beta-D-glucosaminidase (GZ), and peroxidase (P) was assessed using a semiquantitative cytochemical method in peritoneal macro phages of 30 patients with end-stage renal failure treated by intermittent peritoneal dialysis and of 30 control patients with normal renal function.

The dialysed patients showed a significantly higher activity of GR and P at the beginning of the treatment as compared with the respective activities observed in the control group and a further significant rise of these activities after 4 months of dialysis. Activity of AP at the beginning of the treatment was insignificantly lower than in the control group and the difference became significant at the end of the investigated period. There was no significant difference between the dialysed patients and the control group in the activity of GZ assessed at the beginning of the dialytic treatment and after 4 months of dialysis. A significant decrease in that activity was, however, observed in the course of dialysis.

Hairy Cell Leukemia: Enzyme-histochemical and Ultrastructural Investigation of one Case

The investigation was carried out on blood smears, bone marrow aspirates, one lymph node biopsy, and the surgically removed spleen of a 53-year-old man with hairy cell leukemia. In the blood smears stained with May-Grünwald-Giemsa, 60 to 70 % of the hairy cells contained tubular inclusions that corresponded to the ribosome-lamella complexes demonstrated at electron microscopy. In blood smears, imprints and cryostatic sections of the lymph node and of the spleen, hairy cells revealed tartrate-resistant acid phosphatase, beta-glucuronidase and adenosine-triphosphatase activity. In the spleen neutral esterase and alkaline phosphatase demonstrated the numerical increase of the histiocytes, which ultrastructurally displayed phagocytic activity. The presence in the spleen of pseudosinuses lined by hairy cells was confirmed by electron microscopy as well as by cytoenzymology.

Enzyme Histochemistry for Functional Histology in Invertebrates

In invertebrates, enzyme histochemistry has recently found a renaissance regarding its applications in morphology and ecology. Many enzyme activities are useful for the morphofunctional characterization of cells, as biomarkers of biological and pathologic processes, and as markers of the response to environmental stressors. Here, the adjustments to classic techniques, including the most common enzymes used for digestion, absorption, transport, and oxidation, as well as techniques for azo-coupling, metal salt substitution and oxidative coupling polymerization, are presented in detail for various terrestrial and aquatic invertebrates. This chapter also provides strategies to solve the problems regarding anesthesia, small body size, the presence of an exo- or endoskeleton and the search for the best fixative in relation to the internal fluid osmolarity. These techniques have the aim of obtaining good results for both the pre- and post-embedding labeling of specimens, tissue blocks, sections, and hemolymph smears using both light and transmission electron microscopy.

Comparative histochemistry of posterior lingual salivary glands of mouse

Normal posterior deep and superficial salivary glands of tongue were examined in male mice by means of light microscopical histochemistry and neurohistology. Both glands showed acini and simple ducts. Demilunes were present in the superficial gland. Disulphides and neutral mucosubstances occurred in acini and demilunes. Tryptophan staining was seen in acini of the deep gland and demilunes, whereas acid mucosubstances were exclusively localised in the superficial gland. Dehydrogenase activities were widespread. Strong esterase activity occurred throughout the parenchyma of the deep gland and in demilunes; it was variably inhibited by E600, apart from acinar apical regions in the deep gland. Lipase was confined to acini of the deep gland and demilunes. Acid phosphatase staining was similarly localised; it was also seen in periluminal ductal rims of the deep gland, in which ouabain-sensitive Na,K-ATPase was localised basolaterally. Staining for alkaline phosphatase decorated occasional myoepithelial-like arrangements and interstitial capillaries. Acetylcholinesterase was associated with nerve fibres embracing glandular parenchyma. Adrenergic fibres were not seen. The results suggest that the acini of the posterior deep lingual gland secrete neutral glycoproteins, whereas the ducts transport ions and absorb luminal material. The posterior superficial lingual gland mainly secretes acid glycoproteins. Both glands produce lingual lipase, receive cholinergic-type innervation and have inconspicuous myoepithelium.

A first insight into haemocytes of the smooth venus clam Callista chione

The smooth venus clam Callista chione is a commercially exploited bivalve species that lives on the sandy bottom of the Italian coast of the Northern Adriatic Sea. Currently, no information is available in the literature about the haemocytes of this bivalve species. In this study, we performed a morpho-functional characterisation of the haemocytes of C. chione. In freshly collected haemocytes, the total haemocyte count (THC) (measured by a Coulter Counter) varied markedly among individuals, and the mean number of haemocytes was 1.2 (×10(6)) cells mL haemolymph(-1). The mean values for the haemocyte diameter and volume were 4.2 μm and 77.8 fL, respectively. In some cases, higher THC values were related to a smaller haemocyte size, but no correlation was detected between the THC and haemocyte diameter or between THC and cell volume. Conversely, a positive correlation was observed between cell diameter and volume. Two haemocyte types were distinguished by light microscopy: granulocytes (76%), with evident cytoplasmic granules, and hyalinocytes (24%), with a few or no granules. After adhesion to slides and fixation, the cell diameter was approximately 10 μm for granulocytes and 7 μm for hyalinocytes. The granules of the granulocytes were stained in vivo with Neutral Red, indicating that they were lysosomes. The granulocytes and hyalinocytes were further distinguished as basophils and acidophils. Both the granulocytes and the hyalinocytes were able to phagocytise yeast cells. Of 2643 cells that were counted, 2007 (76%) showed phagocytic activity. The granulocytes and hyalinocytes were both positive for some hydrolytic enzymes, whereas they were not positive for peroxidase or phenoloxidase. The two types of haemocytes also produced superoxide anion. Overall, this preliminary study indicates that both the granulocytes and hyalinocytes of C. chione are immune effector cells.

Insight on cellular and humoral components of innate immunity in Squilla mantis (Crustacea, Stomatopoda)

For deeper insights into the function of crustacean haemocytes in immune responses, we studied the morphology and enzyme content of circulating cells of the mantis shrimp Squilla mantis from the North Adriatic Sea, together with their ability to phagocytose foreign cells. We also assayed the enzyme content and the agglutinating and haemolytic activities of cell-free haemolymph. Three haemocyte types, i.e., hyalinocytes, semigranulocytes and granulocytes, can be distinguished, according to cell and nuclear morphology and the presence of cytoplasmic granules. All of them share the same patterns of enzyme activities and are recognised by the same lectins. Spreading cells (hyalinocytes and semigranulocytes) can ingest foreign cells; granules of semigranular and granular cells have similar cytochemical properties. Injection of Micrococcus luteus into the heart sinus results in an increase in the frequency of hyaline cells and a decrease in the frequency of granulocytes. After 24 h from the injection, a decrease in the number of phagocytosing hyalinocytes, and a general decrease in the frequency of acid phosphatase-positive cells was reported. Our data match previous results and suggest the existence of a single differentiation pathway for Squilla haemocytes with the three haemocyte morphs as different stages of cell differentiation. Results also indicate that Squilla haemolymph performs immunosurveillance, through rapid changes in haemocyte distribution, increase of antimicrobial and antioxidant enzymes and secretion of lectins stimulating agglutination, phagocytosis and encapsulation.

The role of haemocytes from the crab Carcinus aestuarii (Crustacea, Decapoda) in immune responses: A first survey

For the first time, a functional study of haemocytes from the crab Carcinus aestuarii was performed in order to evaluate their involvement in immune responses. Total haemocyte count (THC), phagocytosis, haemolymph opsonisation properties, hydrolytic and oxidative enzyme activities, and production of intracellular superoxide anion were evaluated. A great variability in THC was recorded among individuals, and haemocyte mean number was 6.4 (x10(6)) cells/ml haemolymph. Although only hyalinocytes were able to phagocytose yeast cells or Zymosan, phagocytic index was low (3%) and did not increase significantly (4%) after pre-incubation of yeast and Zymosan in cell-free haemolymph, suggesting that haemolymph did not have opsonising properties. All haemocyte types produced superoxide anion, whereas only granulocytes were positive to the hydrolytic enzymes assayed. In addition, only granulocytes were positive to phenoloxidase activity. Both Petri dish and spectrophotometric assays revealed a very low lysozyme-like activity in cell-free haemolymph (CFH) and haemocyte lysate (HL), although enzyme activity was higher in CFH than in HL. Interestingly, normalisation of data as to total protein content in CFH and HL resulted in an opposite situation, lysozyme-like activity being higher in HL than in CFH. This demonstrated that haemolymph of C. aestuarii has a high quantity of total proteins, functional properties of which need to be better investigated in future studies. Overall, the results obtained in the present study indicated that C. aestuarii haemocytes are not very active phagocytic cells, but they are more active in terms of both hydrolytic and oxidative enzyme activities and superoxide anion production.

Haemocytes of the cockle Cerastoderma glaucum: morphological characterisation and involvement in immune responses

For the first time, morpho-functional characterisation of haemocytes from the cockle Cerastoderma glaucum was performed to identify circulating cell types and to study their involvement in immune responses. Haemocyte mean number was 5.5 (x 10(5)) cells/mL haemolymph. Two main haemocyte types were found in haemolymph: granulocytes (85%), about 10 microm in diameter and with evident cytoplasmic granules, and hyalinocytes (15%), 8 to 14 microm in diameter, with a few or no granules. Most of the cytoplasmic granules stained in vivo with Neutral Red, indicating that they were lysosomes. On the basis of haemocyte staining properties, granulocytes and hyalinocytes were further classified as basophils and acidophils. Acidophil hyalinocytes were the largest haemocyte type (about 14 microm in diameter) and had an eccentric nucleus and a large cytoplasmic vacuole. Both granulocytes and hyalinocytes (except acidophils) were able to phagocytise yeast cells, although the basal phagocytic index was very low (about 2%). It increased significantly (up to 26%) after pre-incubation of yeast in cell-free haemolymph, suggesting that haemolymph has opsonising properties. Haemocytes also produced superoxide anion. Moreover, both granulocytes and hyalinocytes (except acidophils) were positive for some important hydrolytic and oxidative enzymes. Lysozyme-like activity was recorded in both cell-free haemolymph and haemocyte lysate, although enzyme activity in cell lysate was significantly higher. Results indicate that haemocytes from C. glaucum are effective cells in immune responses.

Ozone Therapy in Induced Endotoxemic Shock. II. The Effect of Ozone Therapy Upon Selected Histochemical Reactions in Organs of Rats in Endotoxemic Shock

Mitochondria and lysosomes were evaluated by assessment of changes in activity of selected enzymes: lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), adenosinetriphosphatase (ATPase), acid phosphatase (AcPase) and beta-glucuronidase (BG) in rats under profound hypoxia induced by endotoxemic shock. The study was conducted on adult male Wistar rats. The animals formed the following four groups of 15 rats each: control animals (C);-rats receiving intraperitonally O(2)/O(3) (CO), rats receiving of Escherichia coli toxin (LPS) (CL); rats receiving LPS plus oxygen-ozone mixture (OL). Histoenzymatic examinations of liver, kidney, lungs, and heart muscle were performed. Lipopolysaccharide suppressed activities of all the enzymes except for LDH, the activity of which as high as a fourfold increase. The results demonstrated potent, stabilizing and regenerative effects of ozone therapy on body enzymatic processes in course of induced endotoxemic shock in rats, which might prove to be of clinical significance.

Histological and histochemical observations on salivary microliths in ferret

The fortuitous observation of salivary microliths in ferret was pursued in the present investigation. Major salivary glands obtained post-mortem from mature ferrets of either sex were examined with the use of histology and light microscopical histochemistry for calcium, protein, amino acids, mucosubstances and hydrolytic enzymes. Microliths were detected in most parotids, but were absent from submandibular and sublingual glands. The microliths were usually seen in lumens, and occasionally in parenchyma and interstices. They were variably stained for calcium, tryptophan, and neutral and acidic mucosubstances, similarly to acinar or ductal secretory granules. Unlike secretory granules, microliths showed autofluorescence, high levels of tyrosine and a low concentration of -SS- groups. Acid phosphatase and beta-glucuronidase reaction surrounded non-luminal microliths. The present data establish ferret as a new model for the investigation of salivary microliths and do not support the notion of microliths being almost absent from the parotid. Probably there is secretory inactivity in ferret parotid and this fosters the formation and accumulation of microliths containing calcium and disintegrated secretory material.

Organic secretory products, adaptive responses and innervation in the parotid gland of ferret: A histochemical study

To qualify cellular events of possible pathophysiological significance in the parotid of ferret, tissue obtained post-mortem from mature animals of either sex was examined by light microscopical histochemistry for calcium, protein, amino acids, mucosubstances and hydrolases, and by neurohistology. Calcium was localised in acinar cells replete with granules containing protein, disulphides and usually carboxylated mucosubstances. Acid phosphatase activity was basally concentrated in the acinar cells. The granular luminal region of striated ductal cells showed protein, tryptophan, disulphides, neutral mucosubstances, and E600-sensitive esterase and Naphthol AS-D chloroacetate esterase activities, whereas their basal region showed acid phosphatase activity. Strong periluminal activity of acid phosphatase and E600-resistant esterase characterised the collecting ducts. Cholinesterase activity was associated with an extensive network of nerve fibres embracing parenchyma. Catecholamine fluorescence was not seen. beta-glucuronidase reactive macrophages abounded in the interstices. The results suggest that while the acini in the parotid of ferret secrete polyionic glycoproteins, shielded by calcium, the striated ducts secrete tryptophan-rich products comprising neutral glycoproteins and showing proteolytic activity. Innervation is of the cholinergic type and parenchymal lysosomal activity, possibly related to autophagy of stored secretory products and heterophagy of luminal material, is brisk. Macrophages contribute to maintaining the glandular microenvironment, wherein secretory activity appears to be lethargic.

Histologic and Histochemical Changes in Rabbit Cornea Produced by an Orthokeratology Lens

PURPOSE

To report the histologic and histochemical properties of rabbit cornea after insertion of an orthokeratology lens.

METHODS

An orthokeratology lens was placed on the left corneas of rabbits for 8 hours daily, and their eyes were enucleated after 7, 14, 21, and 28 days and examined histologically and histochemically. The right eyes were used as controls.

RESULTS

After 7-14 days, hematoxylin and eosin staining of the cornea revealed that the epithelial layer was slightly thinner in the central area and thicker in the intermediate area, but its thickness gradually became normal toward the limbus. Periodic acid-Schiff staining showed no abnormal distribution of glycogen granules or glycogen producing cells. 5-bromo-2-deoxyuridine staining revealed more mitoses in the central area than in the intermediate area. Histochemical staining showed lactic dehydrogenase activity in the central area of the lens, whereas alkaline phosphatase activity and beta-glucuronidase activity were slightly increased in the intermediate area. There were no other clearly abnormal findings.

CONCLUSIONS

The thickness of the corneal epithelium showed topographical variation consistent with the effect of orthokeratology. The result of histochemical studies suggested that there were no marked alterations in epithelial function.

Mechanical disturbance affects haemocyte functionality in the Venus clam Chamelea gallina

The clam Chamelea gallina is fairly common along the western coastline of the Adriatic Sea, where it is subjected to intense fishing. To evaluate possible causes of stress in clam populations, the effects of acute mechanical disturbance on haemocyte functionality were analysed in both laboratory and field experiments. Among the various sources of stress that clams undergo during commercial fishing by hydraulic dredges, water pressure and mechanical sorting were considered, and three increasing levels of stress were applied. A reduction in immunosurveillance was highlighted, concentrations of circulating haemocytes, phagocytic and acid phosphatase activity indices decreased with increasing mechanical stress. The opposite trend shown by the beta-glucuronidase activity index is discussed. The response of clam haemocytes, detected on seasonal bases in two sites, often exhibited peculiar patterns, mostly depending on the reproductive cycle, and were probably influenced by different features of the sea bottom. Although recovery after stress was observed in laboratory experiments, some considerations are made on detrimental effects experienced in the field by under-sized clams, which are first fished and then thrown back into the sea.

Histochemical phenotypes of von Ebner's gland of ferret and their functional implications

Von Ebner's gland of ferret was examined by means of light microscopy, protein, mucosubstance and enzyme histochemistry, and neurohistology. Acinar cells were replete with granules containing neutral mucosubstances and disulphides, and showed strong diffuse acid phosphatase activity and weak granular staining for peroxidase. Staining for cytochrome oxidase, succinate dehydrogenase, and NADH and NAD(P)H dehydrogenases was also seen. Basolateral plasmalemma of acinar cells showed weak, ouabain-sensitive Na+,K+-ATPase activity. Ductal cells were of a simple appearance, contained thiols and showed variable staining for acid phosphatase, dehydrogenases and cytochrome oxidase. Variable amounts of beta-glucuronidase reaction product were localized in the glandular parenchyma, being marked in atrophic areas. Prominent stellate myoepithelial cells embracing acini and also basal ductal cells were demonstrated by alkaline phosphatase. Thiamine pyrophosphatase reaction product was concentrated in blood vessels around parenchyma, with little Golgi-like staining in acinar cells. Acetylcholinesterase activity was associated with an extensive network of nerve fibres embracing parenchyma, whereas catecholamine fluorescence was not seen. The results suggest that the acini of von Ebner's gland of ferret synthesise neutral secretory glycoproteins and peroxidase. Water mobilization is inconspicuous. Lysosomal activities feature in the parenchyma, possibly a consequence of processing secretory products in acini, absorption in ducts and/or adaptation atrophy. The gland receives a rich cholinergic-type innervation, and has extensive myoepithelial and microvascular networks.

Haemocytes of the clam Tapes philippinarum (Adams & Reeve, 1850): morphofunctional characterisation

Tapes philippinarum is a bivalve mollusc of the Pacific Ocean, successfully imported for human consumption into the northern Adriatic Sea (Europe). For better knowledge of its considerable adaptive ability in comparison with similar autochthonous species, a morpho-functional characterisation of its haemocytes was carried out with the establishment of short-term cell cultures (60 min at 25 degrees C). Various methods of cytochemical staining identified four cell types in the haemolymph: granulocytes (48.05% +/- 1.43), hyalinocytes (32.18% +/- 0.99), haemoblasts (18.97% +/- 0.63) and serous cells (0.8% +/- 0.19). The granulocytes, possessing cytoplasmic granules with differing dye affinity, included basophils, neutrophils and acidophils. Such granules stained vitally with Neutral Red, and correspond to lysosomes. Hydrolytic and oxidative enzymes were mainly detectable after stimulation in the presence of yeast cells. Both granulocytes and hyalinocytes were positive for alkaline phosphatase, non-specific esterase, peroxidase, and cytochrome C oxidase, whereas only granulocytes were positive for beta-glucuronidase, acid esterase, and arylsulphatase. Both cell types were competent phagocytes towards yeast and plasma had an opsonising effect. Moreover, the respiratory burst accompanied phagocytosis with superoxide anion production, recognisable through cytoplasmic deposits of formazan after treatment with nitro blue tetrazolium. Haemoblasts were small undifferentiated cells which, due to their morphology and positivity to the anti-CD34 antibody, show the typical features of stem cells. Serous cells, probably arising from Keber's gland and belonging to another differentiation pathway, contained non-sulphate acid mucopolysaccharides and play an important role in early defence mechanisms, taking part in the formation of clots.

Reversal of pathology in the entire brain of mucopolysaccharidosis type VII mice after lentivirus-mediated gene transfer

Gene transfer vectors derived from human immunodeficiency virus (HIV-1) efficiently transduce nondividing cells and remain stably integrated in their genome. Long-term expression of reporter genes has been documented after intracerebral injection of these vectors. Using a HIV-based vector, we looked for a reversal of brain damage in the beta-glucuronidase-deficient mucopolysaccharidosis type VII mouse, an animal model of human lysosomal storage diseases. The vector suspension was injected stereotactically in the brain of 10-week-old animals, an age at which storage lesions are patent in glia, perivascular cells, and neurons. Either a single intrastriatal injection or multiple injections in both cerebral hemispheres and in the cerebellum were performed. Local tolerance, enzyme delivery, and correction of storage lesions were investigated by comprehensive analysis of serial sections of the entire brain of mice killed 6 or 16 weeks postinjection. Histochemical staining detected enzyme activity in widely distributed areas, the size of which increased with time. Clearance of lysosomal storage extended far beyond enzyme-positive areas. In mice receiving multiple injections of the vector, complete correction or significant reduction of the pathology was observed in every section, suggesting disease regression in the entire brain. These results may have implications for the treatment of neurological symptoms in lysosomal storage diseases.

Long-term and significant correction of brain lesions in adult mucopolysaccharidosis type VII mice using recombinant AAV vectors

Most lysosomal storage diseases, including mucopolysaccharidosis, affect the central nervous system (CNS). They often induce severe and progressive mental retardation. Replacement therapy by purified enzyme infusions is a promising approach for the treatment of peripheral organs but without effect on CNS pathology because the enzyme cannot cross the blood-brain barrier. Intracranial injection of recombinant adeno-associated virus (AAV) vectors offers an alternative for sustained local enzyme delivery from genetically engineered cells. We stereotactically injected an AAV vector containing the human beta-glucuronidase cDNA into the striatum of adult mice severely affected by mucopolysaccharidosis type VII at the time of treatment. Six weeks later, beta-glucuronidase activity in the injected hemisphere was comparable to that of heterozygous mice, which have a normal phenotype. Areas staining positive for enzyme activity enlarged with time, representing more than 10% of the hemisphere volume by 16 weeks. A complete reversion of lysosomal storage lesions was evident in these areas, as well as in most neurons located in surrounding negative areas and in the noninjected hemisphere. Thus, a single intracerebral injection of AAV vectors could achieve a broad and sustained lysosomal enzyme delivery, allowing for stable reversion of storage lesions in a significant fraction of the adult brain.

Morphological phenotypes and functional capabilities of submandibular parenchymal cells of the ferret investigated by protein, mucosubstance and enzyme histochemistry

Submandibular glands obtained post-mortem from mature ferrets of both sexes were examined with the use of light microscopical histochemical methods for proteins, mucosubstances and enzymes associated with cell functions or organelles. Demilunar cells showed carboxylated mucosubstances that were mainly non-sulphated, and diffuse activity for peroxidase, E600-sensitive esterase and acid phosphatase. Thiol groups were also detected in these cells. Central acinar cells showed sulphated mucosubstances, disulphides and reticular staining for thiamine pyrophosphatase. Intercalary ducts showed diffuse activity for NADH and NAD(P)H dehydrogenases. Striated ducts contained protein, tryptophan, disulphides, neutral mucosubstances and E600-sensitive esterase periluminally. Basally, the striated ductal cells showed variable activity for peroxidase, cytochrome oxidase, succinate dehydrogenase and acid phosphatase. Basolateral plasma membranes of these cells exhibited ouabain-sensitive Na,K-ATPase activity. The collecting ducts were characterized by variable periluminal staining for acid phosphatase, beta-glucuronidase, acid beta-galactosidase and E600-resistant esterase. The results suggest that the histological appearances of the acini of the submandibular gland of the ferret are dependent on the synthesis of secretory acid glycoproteins, that the striated ducts are involved with the secretion of tryptophan-rich product comprising neutral glycoproteins and showing esterase activity and with marked transport of ions and that the collecting ducts are involved with absorption.

Long-term delivery of a lysosomal enzyme by genetically modified fibroblasts in dogs

We have evaluated the feasibility and efficacy of intraperitoneal implants (neo-organs) for protein delivery in large animals. Skin biopsies were taken from four healthy dogs. Primary fibroblast cultures were transduced with a retroviral vector coding for the human beta-glucuronidase. One to six lattices each containing 10(9) skin fibroblasts were implanted into the omentum of the donor animal. Laparotomies performed at regular intervals showed vascularized neo-organs without local inflammation. Human beta-glucuronidase levels equivalent to 0.8 to 3.1% of the endogenous canine activity were detected for up to 340 days on liver biopsy samples. These results indicate that neo-organs can be considered for the long-term delivery of therapeutic proteins or enzymes in humans.

Organ culture of benign, aging, and hyperplastic human prostate

Organ culture of the human prostate began in the 1970s and was modeled after the work of Lasnitzki and her collaborators in the mouse two decades earlier. In organ culture of human prostates, one sees a rapid increase in epithelial cells and decrease in stromal cells during the first 3-5 days of culture. While modulation of many phenotypic properties occurs, these cultures provide a simple and rapid way to achieve large numbers of human prostatic epithelial cells in cultured tissues that are markedly depleted of stromal cells. There is some evidence that organ cultures are maintained in slightly better functional states in the presence of androgens; however, most of this evidence is less than quantitative. Most organ culture of prostates has been accomplished with tissues from unspecified locations within the prostate; interpretation of cultures carried out in this fashion has been less complete than would have been possible if they had been carried out from specific anatomic locations within the prostate. Careful pathological characterization of locations contiguous to the cultured tissue is mandatory if cultures are to be interpreted meaningfully.

Reticulo-endothelial stroma of the head-kidney from the seawater teleost gilthead seabream (Sparus aurata L.): an ultrastructural and cytochemical study

BACKGROUND

Head-kidney, considered the major fish lympho-haemopoietic tissue, consists of cells of the different haemopoietic series supported by a network of stromal cells whose morphofunctional properties have not been established. We report the ultrastructure and cytochemical features of the reticulo-endothelial stroma of the head-kidney from the seawater teleost gilthead seabream (Sparus aurata L.).

METHODS

Samples of head-kidney were processed for electron microscopic study. Some of the samples were incubated for acid and alkaline phosphatase, peroxidase, glucose-6-phosphatase, or ATPase.

RESULTS

The reticulo-endothelial stroma of gilthead seabream head-kidney consists of sinusoidal cells (endothelial and adventitial cells) and reticular cells (macrophage-type reticulum and fibroblast-like reticular cells). Transcytosis vesicles and rounded medium electron-dense granules were observed in the cytoplasm of the endothelial cells. The adventitial cells partially covered the outside surface of the endothelial cells and were joined by desmosomes. The macrophage-type reticulum cells were characterized by their cytoplasmic processes and acid phosphatase positive lysosomes. The fibroblast-like reticular cells were joined by desmosomes and formed an extensive network between the haemopoietic parenchyma. They were peroxidase negative and acid and alkaline phosphatase, glucose-6-phosphatase, beta-glucuronidase, and ATPase positive.

CONCLUSIONS

The ultrastructural and cytochemical features of the reticulo-endothelial stroma of the gilthead seabream head-kidney are similar to those of mammalian bone marrow, suggesting phylogenetic analogies between both tissues.

Mixed tumours of the skin: a histopathological, enzyme-histochemical and immunohistochemical study

Twenty-eight cases of mixed tumour of the skin were studied and subclassified into three types: eccrine (1 case), indeterminate (7), and apocrine type (20). The indeterminate type was defined as mixed tumours having tubuloalveolar patterns with two layers of epithelium, ut without apocrine secretion or pilosebaceous differentiation. Enzyme-histochemical studies were performed on four cases (one indeterminate, three apocrine): in the indeterminate type the tubular epithelial cells showed eccrine differentiation while in the apocrine type tubules were found showing the direction of differentiation to be toward the apocrine gland, but tubules with eccrine differentiation were intermingled in all three. Immunohistochemically, no differences were observed between the indeterminate and the apocrine type: hints of eccrine features were observed in both groups. Thus, the indeterminate type could be an eccrine tumour and the apocrine type showed direction of differentiation toward both eccrine and apocrine glands. It is concluded that mixed tumours of the skin are fundamentally eccrine neoplasmas, and that the apocrine features may represent apocrine metaplasia.

Correction of lysosomal storage in the liver and spleen of MPS VII mice by implantation of genetically modified skin fibroblasts

Genetic defects of lysosomal hydrolases result in severe storage diseases and treatments based on enzyme replacement have been proposed. In mice lacking beta-glucuronidase, which develop a disease homologous to human mucopolysaccharidosis type VII (Sly syndrome), we have used autologous implants of genetically-modified skin fibroblasts for the continuous in vivo production of the enzyme. The human beta-glucuronidase cDNA was introduced with a retroviral vector into mutant mice skin fibroblasts grown in primary culture. Fourteen mutant mice were implanted intraperitoneally with these modified cells embedded into collagen lattices. All animals expressed beta-glucuronidase from the vascularized neo-organs that developed after implantation and accumulated the enzyme in their tissues. A complete disappearance of the lysosomal storage lesions was observed in their liver and spleen.

Cytoplasmic inclusions in spinal neurons of the motor neuron degeneration (Mnd) mouse. I. Light microscopic analysis

The motor neuron degeneration (Mnd) mutation in the mouse is a late onset, autosomal dominant, neurodegenerative disease in which ventral horn neurons have been shown to contain numerous, large cytoplasmic inclusions. Histochemical and immunocytochemical studies performed on spinal cord from Mnd/Mnd mice in late stages of the disease showed the inclusions to contain protein, lipid and carbohydrate moieties. Spinal neurons, especially those in spinal lamina IX, contained increased beta-glucuronidase activity in the form of large cytoplasmic inclusions. Such inclusions also contained increased acid phosphatase and trimetaphosphatase activity. When immunostained with antiubiquitin antibodies, intracellular ubiquitin deposits were present as accumulations of varying size; some were amorphous while others contained small granules. Extraneuronal ubiquitin deposits were detected in the neuropil. Immunostaining with monoclonal antibody ML30, used here to assay for the presence of a mitochondrial epitope in the inclusions, was widespread and punctate in white and grey matter from Mnd/Mnd and age-matched control spinal cords. The overall pattern of staining was similar for both tissue sources and did not correspond to any of the other probes which reacted with the inclusions in Mnd neurons. The presence of increased levels of lysosomal hydrolases and ubiquitinated molecules suggests that the two general systems for intracellular digestion are activated in Mnd/Mnd spinal neurons.

Neuronal toxicity by macrophages in mixed brain cell culture is augmented by antineuronal IgG and dependent upon nitric oxide synthesis

We used mixed brain cell cultures derived from dissociated neonatal rat cerebella to study interactions between mononuclear phagocytes and brain cells under various conditions. We found that activated macrophages were capable of selectively killing neurons, leaving other cells undisturbed. Moreover, this activity was dependent upon nitric oxide production and, to a weaker extent, upon the NMDA receptor but not upon tumor necrosis factor. Macrophage-mediated neuronolysis was augmented by one of two anti-neuronal antibodies studied.

Genetically defined lysosomal acetylesterase EC 3.1.1.6 in the cauda epididymidis of mouse, rat, and man

After inhibition by bis-p-nitrophenyl phosphate and subsequent staining for esterase using naphthol AS-D acetate as the substrate, a strong lysosomal esterase was demonstrated in the cauda epididymidis of mouse, rat, and man. Owing to its behaviour towards the classifying inhibitors eserine, diisopropyl fluorophosphate, bis-p-nitrophenyl phosphate, and p-chloromercuriphenylsulphonate, this lysosomal esterase was shown to be an acetylesterase (EC 3.1.1.6). Control experiments involving isoelectric focusing revealed that this acetylesterase was identical with the genetically defined homologues ES-17, ES-6, and ES-A4 in mouse, rat, and man, respectively.

Cell mixing in the spinal cords of mouse chimeras

With the aim of determining whether there is significant cell mixing during development of the spinal cord, experimental chimeric mice containing two genetically distinct cell populations were produced by aggregating BALB/c or BALB/c x LPT hybrid embryos with C3H/HeN embryos. The BALB/c and LPT hybrid spinal cord cells were distinguished histochemically from the C3H/HeN spinal cord cells by using beta-glucuronidase as an independent cell genotype marker. BALB/c and LPT hybrid cells have high levels of beta-glucuronidase activity, while the C3H/HeN cells have low levels. The spinal cords of the chimeras were dissected out regionally (i.e., cervical, thoracic, and lumbar areas) and were sectioned serially. Each region was then analyzed by scoring large- and medium-sized neuronal cell bodies (greater than or equal to 10 microns) whose genotypes were distinguished by their beta-glucuronidase levels. Observations of seven chimeric mice, with coat colors that varied from one extreme (5% albino) to the other (90% albino), suggest that each chimeric spinal cord is a relatively homogeneous population throughout its length. On average only 4 to 5 percentage point differences were observed when comparing left-right, cranial-caudal, and dorsal-ventral regions within a given chimera. The cell mixing, however, is not total, and regional variations were noted. Maximum left-right differences between different spinal cord levels never exceeded 18 percentage points, while in the entire cord the maximum left-right difference was 11 percentage points. When considering dorsal-ventral differences, 18 and 15 percentage points were observed within the spinal cord levels and the entire cord, respectively. However, when comparisons were made between smaller subregions (e.g., right-dorsal-cervical vs left-ventral-lumbar), larger differences of up to 30 percentage points were observed. In addition, the genotype proportions in the spinal cord were closely correlated with the visually estimated proportions of coat color genotypes.

Osteosarcoma with features mimicking malignant fibrous histiocytoma

Three osteosarcomas (OS) with features resembling malignant fibrous histiocytoma (MFH) were selected and investigated to identify any clinico-pathological similarities. In all cases there was no significant difference from conventional OS on the radiography and laboratory data. The appearance of MFH-like features within the whole tumour tissue varied from 7% to 55%. It was composed of spindle-shaped cells arranged in short irregular fascicles and a storiform pattern admixed with osteoclast-like giant cells, but devoid of neoplastic osteoid. Such spindle-shaped cells had a poorly developed rough endoplasmic reticulum and expressed a strong alkaline phosphatase activity as well as vimentin. A series of allografts to athymic mice using the MFH-like tissues also showed histologically a proliferation of plump spindle-shaped cells with a storiform pattern lacking osteoclast-like giant cells, and intensely positive for alkaline phosphatase. These findings indicate that the MFH-like features are identified as modulated OS. The constituting cells are most likely to be poorly developed with possible phenotypic alteration in the maturation stage of osteoblastic cell lineage, but different from conventional MFH of bone as regards their distinct histochemical pattern.

Indomethacin inhibits the chemical carcinogen benzo(a)pyrene but not dimethylbenz(a)anthracene from altering Langerhans cell distribution and morphology

Treatment of murine skin with the polyaromatic hydrocarbon carcinogens benzo(a)pyrene (BP) or dimethylbenz(a)anthracene (DMBA) for 3 weeks resulted in an increase and a decrease in epidermal Langerhans cell (LC) numbers, respectively, compared with solvent-treated skin. Implantation of subcutaneous indomethacin pellets prior to carcinogen treatment prevented the changes in LC numbers and morphology in BP, but not DMBA-treated skin. Indomethacin treatment was also found to reduce elevated prostaglandin E2 (PGE)2 levels in the skin of BP-treated mice, whereas PGE2 levels were not significantly raised in DMBA-treated mice. There thus appears to be a link between altered prostaglandin levels and LC numbers in murine skin treated with BP, but not DMBA. In the latter, LC numbers were reduced by mechanisms not reversed by indomethacin. It is concluded that increased prostaglandin levels may contribute to the impairment of cutaneous immunity previously observed in BP-treated mice by altering LC density and morphology within the epidermis.

Distribution of acid phosphatase and beta-glucuronidase in the hypoplastic cerebellum of jaundiced Gunn rats. An enzyme histochemical study

Activities of acid phosphatase and beta-glucuronidase in the cerebella of young jaundiced (j/j) and non-jaundiced (j/+; control) Gunn rats were studied with the enzyme histochemical method. The cerebellum of j/+ rats showed high acid phosphatase activities in Purkinje cells and neurons in the cerebellar nuclei. In j/j rats, a number of neurons were lost and numerous microglialike cells with a high acid phosphatase activity appeared in the hypoplastic cerebellum. Although beta-glucuronidase activity was rarely detected in the control cerebellum, a high enzyme activity was observed associated with microglialike cells in j/j rats. The present results provide a cytological basis for the reported differential increase in the activities of these lysosomal enzymes in the j/j rat cerebellum.

beta-Glucuronidase is transported slowly to lysosomes in BW5147 mouse lymphoma cells: evidence that the prelysosomal enzyme is not restricted to the endoplasmic reticulum

The post-translational processing of beta-glucuronidase in BW5147 mouse lymphoma cells is slow relative to other newly synthesized lysosomal enzymes. To characterize this slow maturation the acid hydrolase was immunoprecipitated from cells pulse-labeled with [2-3H]mannose. Radiolabeled beta-glucuronidase migrated as the precursor form of the enzyme for up to 4 h of chase, whereas another acid hydrolase, beta-galactosidase, was processed completely to its mature form within this same time period. Both beta-glucuronidase and beta-galactosidase obtained high levels of mannose 6-phosphate (Man 6-P) within 60 min of their biosynthesis. The Man 6-P content of beta-galactosidase declined rapidly during a subsequent chase while that of beta-glucuronidase remained high during the first 4 h of chase and then slowly declined. 3H-Labeled phosphorylated high mannose-type oligosaccharides isolated from beta-glucuronidase after 1 h of chase were composed primarily of species with one or two phosphodiester groups, but oligosaccharides with one and two phosphomonoesters became the predominant phosphorylated species with longer chase times. The phosphorylated oligosaccharides attached to other newly synthesized acid hydrolases, on the other hand, contained primarily phosphodiester species at all chase times. When BW5147 cells were pulsed with [3H]mannose and chased in the presence of monensin to disrupt transport, the number of phosphorylated oligosaccharides recovered from beta-glucuronidase was comparable to the quantity recovered from the enzyme produced by non-drug-treated cells. The number of phosphorylated units recovered from all other newly synthesized acid hydrolases, however, was greater in the presence of the ionophore than in its absence. Nondenaturing gel electrophoresis studies indicated that beta-glucuronidase existed in two forms at steady state within BW5147 cells and, as such, was similar to liver beta-glucuronidase in which a large percentage of the enzyme was present as a complex bound to egasyn. These data suggest that newly synthesized beta-glucuronidase produced by BW5147 cells complexes with an egasyn-like protein within the endoplasmic reticulum. This interaction retards the enzyme's migration through the secretory apparatus but does not prevent its access to Golgi-associated processing enzymes.

Antiproliferative effect of dietary glucarate on the Sprague-Dawley rat mammary gland

Dietary glucarate has previously been shown to inhibit chemical carcinogen-induced rat mammary tumorigenesis. It is demonstrated in this paper that in the mammary gland of the female Sprague-Dawley rat, feeding glucarate at a dose of 70 mmol/kg AIN76A diet for 2 weeks beginning at 35 days of age, markedly reduces [3H]thymidine labeling. Specific histochemical staining for beta-glucuronidase is used to show that the glucarate diet fed to rats for 2-4 weeks inhibits beta-glucuronidase activity in the mammary gland and has a marked antiproliferative effect on mammary epithelium. Glucarate may inhibit rat mammary carcinogenesis, in part, by changing the proliferative status of the target organ.

Malignant hidroacanthoma simplex

A case of malignant hidroacanthoma simplex is described. Histological examination revealed that the malignant cells had arisen from a tumor cell nest of benign hidroacanthoma simplex and invaded the dermis. Two years and 7 months after the excision of the original thigh lesion, a groin lymph node metastasis was discovered. The metastatic tumor cells in the lymph node were histologically similar to the carcinoma cells in the original thigh lesion and had enzymatic and ultrastructural features resembling eccrine sweat duct.

DNA synthesis in Langerhans' cells of mouse ear epithelium revealed by tritiated thymidine autoradiography and histochemical staining for non-specific esterase and beta-glucuronidase activity

The proportion of Langerhans' cells in DNA synthesis in normal mouse skin was assessed by combining tritiated thymidine [3H]TdR autoradiography with enzyme histochemistry. After injection of [3H]TdR, ear skin was treated in two ways. Epithelial sheet preparations were stained for the presence of non-specific esterase and cytospin preparations of epithelial cell suspensions were stained for beta-glucuronidase activity. The labelling index (+/- SE mean) for cytospins, 40 min after injecting [3H]TdR, was 1.6 +/- 0.15%, doubling to 3-4% from 7-17 days after injection. The sheet preparations showed the proportion of label attributable to paired Langerhans' cells rising from 18% at 40 min after injection, to approximately 45%, on days 1-4 after injection. These results suggest that the proliferation of Langerhans' cells in normal mouse skin might be higher than was previously thought to be the case.

Enzyme cytochemistry of unfixed leukocytes and bone marrow cells using polyvinyl alcohol for the diagnosis of leukemia

Cytochemical methods for the demonstration of enzyme activities in blood and bone marrow cells were systematically improved by the addition of an inert polymer, polyvinyl alcohol (PVA), to the incubation medium and by using optimized reaction media. The methods investigated were tetrazolium salt methods for lactate, glucose-6-phosphate, succinate and glutamate dehydrogenase, the indoxyl-tetrazolium salt method for alkaline phosphatase, the diaminobenzidine method for peroxidase, and diazonium salt methods for chloroacetate esterase, beta-glucosaminidase, beta-glucuronidase, acid phosphatase, and dipeptidylpeptidase II and IV. PVA in the media preserved the morphology of cells very well and prevented leakage of large molecules such as enzymes from the cells. Therefore, fixation or long periods of air-drying prior to incubation leading to substantial loss of enzyme activity could be avoided. A brief period of drying (2 min at 37 degrees C) of the cell preparations just before the incubation was sufficient for making the cells permeable. Localization of enzyme activities was very precise and precipitation of the final reaction product was confined to sites which are known to contain the enzyme under study (granules, mitochondria, lysosomes). These advantages advocate the use of PVA in haematological enzyme cytochemistry and especially for diagnosis of leukemia.