Eosinophilic Droplets Research Articles

Sodium dichloroisocyanurate toxicity in rats during a 90-day inhalation toxicity study

Sodium dichloroisocyanurate-96% (NaDCC) is commonly used to treat drinking water, industrial water, and wastewater. However, exposure to NaDCC by inhalation can have toxic pulmonary effects in humans. In the present study, we evaluated the potential toxicity of NaDCC following a 90-day inhalation toxicity study in Sprague-Dawley/Crl:CD (SD) rats. The animals were exposed to 0.4, 2.0, or 10.0 mg/m3 NaDCC for 90 days. In addition, male and female rats from the 10.0 mg/m3 group were set up as the recovery group for 14 days. The bronchoalveolar lavage fluid showed a concentration-dependent increase in the total cell count, with a significant increase in neutrophils in both the sexes in the 10.0 mg/m3 group compared to the negative control group. In the 10.0 mg/m3 group, lung organ weight was significantly increased among the female rats. Histopathological examination showed eosinophilic droplets in the olfactory/respiratory epithelium, mucous cell hyperplasia, atrophy/degeneration of the tracheal branches, and wall thickening of the alveolar ducts in the nasal cavity of both sexes in the 10.0 mg/m3 group. The adverse effects of NaDCC exposure were observed to decrease during the 14-day recovery period in both sexes. Based on pathological observations, the “no observed adverse effect concentration (NOAEC)” of inhaled NaDCC was 2.0 mg/m3 for both sexes. These results are expected to provide a scientific basis for inhalation toxicity data of NaDCC.

La néphropathie induite par le lysozyme : une cause rare d’insuffisance rénale dans la leucémie myélomonocytaire chronique

Lysozyme-induced nephropathy is a rare and unknown complication of chronic myelomonocytic leukemia with overproduction of lysozyme by tumoral cells leading to proximal tubular cells injuries. The present case reports a lysozyme nephropathy secondary to chronic myelomonocytic leukemia. We reported a case of a 82-years-old woman who presented an acute renal failure in a context of diarrhea and vomiting. Her background was characterized by untreated chronic myelomonocytic leukemia and high blood pressure. Despite rehydration, renal function deteriorated. Renal biopsy revealed a tubulo-interstitial lysozyme-induced nephropathy with a vacuolization of the tubular epithelium by eosinophilic droplets stained by anti-lysozyme antibody, without tumoral infiltration of the renal parenchyma. Lysozyme-induced nephropathy is a rare disease which can be suspected biologically and needs histologic confirmation. Other causes of renal failure secondary to chronic myelomonocytic leukemia have to be eliminated first in these patients. The treatment is symptomatic and is associated with treatments of the underlying hematologic pathology.

The impacts of individual and combined exposure to cadmium and lead on intraocular pressure, electroretinography, and residual changes in the rabbit eyes.

The human eye is very vulnerable to various environmental pollutants. Cadmium (Cd) and lead (Pb) are widely spread heavy metals. The goal of the existing study is to explore the impact of single or joint exposure to Cd and Pb on the eye indicators. In this study, male New Zealand white rabbits were treated orally for 30 days with Cd (5 mg Cd Cl2/kg bw) associated or not with Pb (12.5 mg lead acetate/kg bw). Fundus and slit lamp examinations, electroretinography (ERG), intraocular pressure (IOP), Cd and Pb residues, and the histopathological picture of the eye were studied. The results revealed that the oral dosing of Cd or Pb evoked a significant (p < 0.05) decline in a- and b-wave amplitudes, under scotopic conditions, and IOP values. Single Pb or Cd treatment showed a significant (p < 0.001) increase in their residues in the whole eye tissue of the Pb- or Cd-treated group. Eye structures of Cd- or Pb-intoxicated rabbit showed mild degenerated changes of cornea and sclera tissues with the presence of irregular variably sized eosinophilic droplets in the lens. Notably, the simultaneous exposure to Cd and Pb leads to an antagonistic outcome in all of the estimated parameters. These findings concluded that oral exposure to Cd or Pb could significantly disturb the vision but their joint exposure caused an opposing effect on nearly all of these disturbances.

Morphological, biochemical, and histopathological postmortem ocular indices following subchronic exposure to cadmium and/or lead in a rabbit model.

Cadmium (Cd) and lead (Pb) are ubiquitous environmental pollutants. There is a dearth of information on the mutual interaction between the antemortem metal intoxication and the postmortem changes of the eye. Thus, this study aimed to follow the morphological, biochemical, histopathological ocular perturbations and the retinal DNA damage up to 8h postmortem (PM) in Cd and/or Pb intoxicated rabbits. The animals orally received 5mg Cd Cl2/kg bw and/or 12.5mg lead acetate/kg bw for 30 consecutive days. At time of death, eye pupil of different groups had a normal diameter except Pb-intoxicated group had marked myosis. After 8h of death, different rabbit's eye corneas appeared wrinkled and covered with thin white cloud while the pupils were in the mydriatic stage. Up to 8h PM, the individual exposure to Cd or Pb resulted in a significant elevation in GGT, urea, K, DNA damage and obvious retinal lesions. However, their co-exposure evoked an antagonistic outcome. The eye of Cd and/or Pb intoxicated rabbit showed mildly degenerated tissue of cornea and sclera and the presence of irregular eosinophilic droplets of variably size in the lens with a gradual degeneration and vacuolization in the different cell layers of retina especially ganglion up to 8h PM. Also, by increasing post mortem interval (PMI), retinal DNA damage in Cd and/or Pb intoxicated group significantly decreased. It is concluded that Cd and/or Pb intoxication induced ocular alterations which retain the same trend in correlation with PMI as natural deaths except for the retinal DNA damage. Also, the simultaneous exposure to Cd and Pb evoked an antagonistic outcome in the eye. The findings of the current study should be taken into consideration when estimating PMI in areas with high Cd and/or Pb contamination.

Effects of exposure to three environmental chemicals on the selected biochemical parameters of the blood plasma of rainbow trout, Oncorhynchus mykiss (Walbaum)

Abstract Rainbow trout Oncorhynchus mykiss at a weight of 115 ± 24 g (mean ± SD) were experimentally injected with di(2-ethylhexyl)phthalate (DEHP), 2,3,7,8-tetrachlorodibenzo-p-dioxine (TCDD) and gamma isomer of hexachlorocyclohexane (γ-HCH ) to evaluate nitrogen metabolism (total protein [TP], blood urea nitrogen, uric acid [UA], creatinine), carbohydrate metabolism (glucose), mineral metabolism (inorganic phosphate[P], total calcium [Cat]), and catalytic activity of enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], lactate dehydrogenase [LD]). After 21 days, the tested xenobiotics, administered by the intraperitoneally route, caused the following effect: in comparison with negative controls, fish injected with DEHP at concentrations of 200 or 50 mg kg-1 of body weight were found to have a higher level of P and lower level of Cat and decreased catalytic concentrations of ALT, AST, ALP and LD in the plasma of the peripheral blood. A higher level of TP and P and a decreased catalytic concentration of ALT were found when TCDD was administered at a dose of 2 μg kg-1. A decrease in the catalytic concentrations of ALT and ALP occurred in fish injected with γ-HCH in a dose of 50 mg kg-1. UA and P levels were decreased in fish injected with γ-HCH in a dose of 5 mg kg-1. DEHP and TCDD caused neutrophilic leucocytosis with a marked left shift. Both concentrations of γ-HCH led to an increase in polychromatophilic erythrocytes. The frequency of micronuclei varied in all experimental groups, including the controls, ranging between 0.8 and 2.1 ‰. Histological examination in fish injected with DEHP at a concentration of 200 mg kg-1 revealed eosinophilic droplets in the epithelium of renal tubules and histological examination in fish injected with γ-HCH at a higher concentration revealed an increased activation of sinusoidal cells in the liver, a fibrous thickening of bile duct walls, bile duct hyperplasia and a periductal inflammatory.

Central odontogenic fibroma: new findings and report of a multicentric collaborative study

The aim of this study was to describe the clinicopathologic and immunohistochemical characteristics of 14 cases of central odontogenic fibroma (COF), and the ultrastructural features of 2 of them. Collaborative retrospective study based on the records of 4 oral pathology diagnostic services in Latin America based on the current World Health Organization classification. There were 7 male and 7 female patients (mean age 31.8 years). Eight tumors occurred in the maxilla and 6 in the mandible. Thirteen cases were epithelium-rich and 1 epithelium-poor COF. Three were classified as hybrid COF with giant cell lesion. Mean size of the hybrid lesions were larger than pure COF (3.8 vs. 2.4 cm). Odontogenic epithelial islands were immunoreactive for cytokeratin (CK) AE1/AE3, CK5, CK14, CK19, and 34BE12 and negative for CK1 and CK18. Langerhans cells positive for S-100 and CD1a were found within the epithelial islands in 6/6 tested cases. CD68 was expressed in the giant cells of the hybrid lesions and in a few mononuclear cells of 2 cases of COF. Ki-67 index was <1% in all cases. In 6 tumors (42.8%), there were small globular eosinophilic droplets within the epithelial islands, which were positive for collagen type IV, and 9/13 cases (69.2%) were focally positive for smooth muscle actin. In addition to fibroblasts, myofibroblastic differentiation was found in the 2 cases studied ultrastructurally. Immunohistochemistry was useful to confirm the presence of epithelium and to exclude other central fibrous tumors. COF also contains a variable number of mast cells, Langerhans cells, and myofibroblasts, and further studies are needed to better understand the participation of these cells in COF histogenesis.

Highly Metastatic Ovarian Yolk Sac Carcinoma in a Rat

We investigated a highly metastatic ovarian yolk sac carcinoma in a 52-week-old female Crl:CD(SD) rat. Macroscopically, the present case had severe ascites, bilateral ovarian masses and numerous nodules in the abdominal and thoracic cavities. Histopathologically, these masses and nodules were generally composed of two types of cells mimicking a parietal and visceral yolk sac. The parietal cells were round to polygonal, contained eosinophilic droplets and were arranged in nests and cords in the eosinophilic matrix. Both the intracytoplasmic droplets and the matrix were stained positively with PAS. The visceral cells were cylindriform, and proliferated in papillary and tubular patterns and occasionally formed Shiller-Duval body-like structures. In the dissemination sites, the neoplastic cells proliferated on the surface of the various tissues and often infiltrated into deeper parts of the tissues. Immunohistochemically, both neoplastic cells were positive for α-fetoprotein and keratin, and the eosinophilic matrix was positive for laminin. Ultrastructurally, the parietal cells had dilated rough endoplasmic reticulums, which were filled with electron-lucent laminated structures. The visceral cells had poorly to moderately developed intracytoplasmic organelles and were interconnected with desmosomes. Taken together, the present tumor was diagnosed as yolk sac carcinoma arising from the ovary and was characterized by not only high metastasis but also invasive infiltration with biphasic proliferation of the parietal and visceral cells.

Oxidative stress is related to the formation of Antoni B patterns and eosinophilic hyaline droplets in schwannomas

Schwannomas, particularly of vestibular origin, often accompany degenerative hypocellular areas known as Antoni B patterns; however, the detailed mechanism is uncertain. Eosinophilic hyaline droplets (EHD), the substantial nature of which are autophagic vacuoles, preferentially appear in acoustic schwannomas and distribute around areas of Antoni B. We investigated their common background using schwannomas with (15 cases) or without (10 cases) EHD, and demonstrated that EHD showed selective immunoreactivity with an anti-nitrotyrosine antibody, suggesting the overproduction of nitric oxide in this condition. The expression of inducible nitric oxide synthase was emphasized in infiltrating macrophages around hyalinized vessels. Protein-bound 4-hydroxy 2-nonenal, another oxidative stress marker, was detected in Antoni B tissue, but not in EHD. Antibodies to cleaved caspase-3 and single strand DNA, indicators of apoptosis, did not label tumors cells in Antoni B areas as well as EHD-bearing cells. The morphology and the mitotically static state of EHD-laden cells are phenotypically similar to autophagic cell death; however, autophagy in normal cells is a cell survival strategy against starvation, so the possibility remains that EHD are formed in that context. In either case, schwannomas may show a characteristic autophagic change by an endogenous mechanism. Tumor growth in a narrow intracranial space and resultant ischemia by self-oppression were postulated to be an initial event, because ischemia-reperfusion injury is a major source of reactive oxygen species and ischemia is also a potent trigger of autophagy as well as of tissue degeneration. Moreover, potential roles of chemokines and hemosiderosis are discussed.

Thirteen-Week Oral Toxicity Study of l,4-Dichloro-2-Nitrobenzene in Rats and Mice

Subchronic toxicity of 1,4-dichloro-2-nitrobenzene (DCNB) was examined by feeding F344 rats and BDF mice of both sexes a diet containing 1,481, 2,222, 3,333, 5,000 or 7,500 ppm DCNB (w/w) for 13 wk. Oral administration of DCNB in feed to rats and mice retarded growth rates and induced subchronic toxicity affecting the liver, kidney, testes and blood. Liver and kidney were most responsive to DCNB. BMDL10 values for relative liver weight were 12.0 and 22.6 mg/kg/d for male and female rats, respectively, and 88.7 and 94.4 mg/kg/d for male and female mice, respectively. Increased liver weights and centrilobular hypertrophy of hepatocytes were observed in the DCNB-fed rats and mice of both sexes. Both increased serum activities of AST and ALT and liver necrosis occurred in the DCNB-fed mice. Increased incidences of hyaline droplets and granular casts in the proximal renal tubules were observed only in the DCNB-fed male rats, indicating alpha2v-globulin nephropathy. Eosinophilic droplets in the renal tubular cells and increased BUN concentrations occurred in the DCNB-fed female rats. DCNB-induced testicular and hematologic changes were noted in rats and mice. On the basis of these results, the highest dose level for the 2-yr bioassay study of rodent carcinogenicity was determined to be 2,000 ppm.

Safety of Oxytetracycline (Terramycin TM‐100F) Administered in Feed to Hybrid Striped Bass, Walleyes, and Yellow Perch

AbstractOxytetracycline (Terramycin TM‐100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55–82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg · kg−1 · d−1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis × white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg · kg−1 · d−1 were significantly smaller than untreated controls. Oxytetracycline‐related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic–lymphopoietic (H&amp;L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&amp;L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg · kg−1 · d−1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline‐related changes observed in this study may be outweighed by disease control benefits.

Distribution and secretory pathways of prostate specific antigen, alpha1-antichymotrypsin and prostate secretory granules in prostate cancers.

Using 19 radical prostatectomy specimens, we studied the histological distribution of free prostate specific antigen (PSA), total PSA, alpha1-antichymotrypsin (ACT) and prostate secretory granules (PSG) in both normal and cancerous cells of the prostate. After glutaraldehyde fixation, numerous fine eosinophilic droplets of PSG could be found mainly in the apical portions of normal acinous epithelial cells, but was markedly decreased in cancer cells. With antibodies against free PSA, normal acinous cells were granularly positive in the apical portion of the epithelium, which corresponded to the PSG, whereas cancer cells were diffusely positive. With antibodies against ACT, normal duct cells and cancer cells were often positive, but few normal acinous cells were positive. Presumably, these findings indicate that free PSA is secreted into the lumen as PSG in normal glands, but not by the same pathway in cancers where free PSA appears to accumulate due to a decrease of PSG, then leak into the blood producing complexed PSA to some extent in the cytoplasm. One factor analysis of variance (ANOVA) on the correlation of tumor differentiation or Gleason score with serum values of total PSA, free PSA and a free/total PSA ratio demonstrated no significant links. Elucidation of secretory mechanisms should provide better comprehension of various PSA indices for prostate cancer screening.

Immunohistochemical demonstration of an enamel sheath protein, sheathlin, in odontogenic tumors.

Enamel proteins can be useful markers for assessment of the functional differentiation of neoplastic epithelium and the nature of extracellular matrices in odontogenic tumors. In the present study, we examined immunohistochemical localization of sheathlin, a recently cloned enamel sheath protein, in various odontogenic tumors to evaluate functional differentiation of tumor cells and the nature of hyalinous or calcified matrices in odontogenic neoplasms. Distinct immunolocalization of sheathlin was observed in the immature enamel of the tooth germ at the late bell stage. Secretory ameloblasts facing the enamel matrix also showed positive staining in their cytoplasm. Definite localization of sheathlin was demonstrated in the enamel matrix in odontogenic tumors with inductive dental hard tissue formation such as ameloblastic fibroodontomas and odontomas. Immunoexpression of sheathlin was, furthermore, demonstrated in eosinophilic droplets in solid nests of adenomatoid odontogenic tumor (AOT) and ghost cells in the epithelial lining of calcifying odontogenic cyst (COC). In AOT, cells facing the eosinophilic droplets also expressed the protein in their cytoplasm. There was neither intracellular staining for sheathlin in the tumor cells nor extracellular staining in the matrix of ameloblastomas and calcifying epithelial odontogenic tumors. Dentin, dysplastic dentin-like hyaline material and cementum in the tumors examined were negative for sheathlin. These results show that immunodetection of sheathlin is a useful marker for functional differentiation of secretory ameloblasts and enamel matrix, which is often hard to differentiate from other hard tissues in odontogenic tumors. Our findings from the view point of sheathlin expression support that the tumor cells of ameloblastomas do not attain full differentiation into functional ameloblasts. It is very interesting that epithelial cells in odontogenic tumors can differentiate into functional ameloblasts without induction by odontogenic mesenchyme, as shown by immunoexpression of sheathlin in eosinophilic droplets within solid epithelial sheets in AOT and ghost cells in the epithelial lining of COC where inductive participation of mesenchymal cells was most unlikely.

The eosinophilic material in adenomatoid odontogenic tumor associated with amyloid protein component

Objective: To investigate the relation between eosinophilic materials and amyloid P (AP) component in adenomatoid odontogenic tumor (AOT). Methods: The expression of amyloid proteins and basement membrane proteins, including type IV collagen, laminin and heparin sulfate proteoglycan (HSPG), in AOT were analyzed by immunohistochemical method. Results: Most eosinophilic droplets among tumor cells and some epithelial cells showed positive stain for AP component. The immunoreactions of type IV collagen and laminin were only found in blood vessels of this tumor. The tumor cells and eosinophilic materials in duct-like structures were constantly unstained for both amyloid and basement membrane proteins. Present results suggest that the nature and composition of eosinophilic droplets may differ from the eosinophilic layer in ductlike structures. This study first demonstrated that the amyloid-like deposition in AOT is associated with AP component by immunohistochemical method. It supported that AP component may be epithelial origin since the AP immunolocalization was found in tumor cells.

Intracytoplasmic eosinophilic hyaline globules in cartilaginous neoplasms: A surgical, pathological, ultrastructural, and electron probe x-ray microanalytic study

Hyaline globules (HGs), spherical intracytoplasmic eosinophilic droplets, have been associated with a variety of conditions, including hepatocellular carcinoma, lung adenocarcinoma, and Kaposi's sarcoma, but they have not been described in cartilaginous tumors. In specimens of 60 cartilaginous neoplasms we found that 22 of 33 chondrosarcomas (67%), eight of 16 enchondromas (50%), and three of seven soft tissue chondromas (43%) exhibited HGs. HGs were seen more commonly in low grade chondrosarcoma (70%) and were relatively rare in high grade chondrosarcoma (25%). No HGs were identified in three osteochondromas, one synovial chondromatosis, or 15 normal cartilaginous tissues taken from various sites. Cartilage associated HGs ranged in size from 2 to 20 μm, were diastase resistant and periodic acid-Schiff (PAS) stain positive, demonstrated autofluorescence, and variably stained with Mallory's phosphotungstic acid-hematoxylin stain (PTAH). A panel of immunostains did not show any specific staining reactions with HGs. Ultrastructurally the HGs were spherical, non-membrane-bound bodies having complex architectural features associated with profiles of rough endoplasmic reticulum. Electron probe x-ray microanalytic (EPXMA) study showed significant peaks of sulphur and calcium. We conclude that HGs represent secretory products of probable glycoprotein nature, may accumulate in a variety of cartilaginous neoplasms, and may be seen more frequently in low grade chondrosarcomas.

Cytoplasmic inclusions of astrocytic elements of glial tumors: special reference to round granulated body and eosinophilic hyaline droplets

Cytoplasmic inclusions of astrocytic elements of glial tumors: special reference to round granulated body and eosinophilic hyaline droplets

Comparative Studies on Lipid Peroxidation in the Kidney of Rats, Mice, and Hamsters and on the Effect of Cysteine, Glutathione, and Diethyl Maleate Treatment on Mortality and Nephrotoxicity After Administration of Potassium Bromate

As an index of lipid peroxidation (LPO), levels of thiobarbituric acid (TBA)-reactive substances were examined in the kidneys of male F344 rats, BDF1, CDF1, and B6C3F1 mice, and Syrian golden hamsters after a single intravenous (IV) administration of potassium bromate (KBrO3) at various doses. In the rats, LPO levels were significantly increased in both a dose-dependent and time-dependent manner. However, when the rats were given intraperitoneal (IP) injection of cysteine, the levels of LPO were not significantly different between KBrO3-treated animals and controls. In CDF1 mice, the slight increases in LPO levels observed were much weaker and not statistically significant. On the other hand, treatment of BDF1 and B6C3F1 mice or hamsters with KBrO3 resulted in decreased values as compared to controls. The effect of treatment with cysteine, glutathione (GSH), or diethyl maleate (DEM) on mortality was tested in male F344 rats given IV injection of KBrO3 at various doses. Significant reduction and elevation in the mortality were observed in rats treated with cysteine or GSH and DEM, respectively. Significant dose-dependent and time-dependent increases were observed in the levels of serum non-protein nitrogen (NPN), blood urea nitrogen (BUN), and creatinine, and absolute and relative weight of the kidneys in male F344 rats administered KBrO3 IV. Microscopically, the appearance of numerous eosinophilic droplets in the cytoplasm of proximal tubular epithelium of KBrO3-treated rats was noteworthy. All these changes were reduced and exacerbated by treatment with cysteine or GSH and DEM, respectively. The possibility of LPO formation in the kidney by active oxygen radicals generated by KBrO3 is suggested. A possible relationship between LPO levels in the kidney and species differences in the renal toxicity and carcinogenicity of KBrO3 is implicated.

Experimental folic acid nephropathy

In rats, single intravenous doses of folic acid induce damage to renal tubular epithelium, deposition of folic acid in tubular lumens, increase in wet kidney weight, oliguria and interstitial connective tissue proliferation. Separation of the nephrotoxic and obstructive effects of folic acid was attempted by pretreatment with NH4Cl or NaHCO3. These effects of folic acid were unaltered by pretreatment with NH4Cl and there was, in addition, accumulation of eosinophilic droplets in papillary collecting duct epithelium. After pretreatment with NaHCO3, folic acid deposition is decreased or absent; there is a smaller increase in wet kidney weight; the rats are polyuric rather than oliguric; interstitial connective tissue proliferation is reduced; and no droplets form in papillary collecting ducts, but lesions are still present in proximal convoluted tubule epithelial cells. These findings indicate that folic acid has direct nephrotoxic effects independent of intraluminal folic acid deposition, and that damage to renal epithelium, unlike that induced by many nephrotoxins, occurs at several levels of the nephron.

Distribution of 54Mn to various tissues of a perry whelk Volutharpa ampullacea perryi in accumulation and excretion phases.

Distributions of 54Mn to various tissues of female and male of perry whelks with ripe gonads were examined in accumulation and excretion phases. The differences in 54Mn distribution be-tween female and male could not be found on any tissues without regard to the phases, and therefore, on the whole bodies or the whole soft bodies as well. These findings differ greatly from the results obtained on Mn and/or 54Mn distributions in bivalves and herbivorous gastropods previously reported elsewhere. The values of i-LI of various tissues were almost equal to each other irrespec-tive of sex, and between accumulation and excretion phases except conchs in which the values of i-LI decreased more rapidly than in other tissues in the latter phase. Concentrations of 54Mn were dependent on weights of most soft tissues, and the correlations were regressed to power functions in accumulation phase. The regression lines were transformed from power functions to linear ones at certain stages in the excretion phase. The excretion curves can finally be super-imposed on the X axis when the nuclide have completely been eliminated from the tissues. Stable-Mn concentration of the ovary was significantly higher than that of the spermary as well as the bivalves and the herbivorous gastropods. A lot of eosinophilic droplets that were identified histochemically to be one of acidic mucopolysaccharides existed in the ripe ovarian tubules. This was not seen for the species whose ova and spermatozoa were discharged directly into the am-bient seawater.

Swine cerebrospinal angiopathy and demyelination and malacia.

In 15 pigs affected with cerebrospinal angiopathy accompanied by demyelination and malacia, the main symptoms were diarrhea and subsequent circling, spasms, sudden forward movements, ataxia, and inability to hold the head straight. Escherichia coli was isolated in a pure culture from the small intestine of pigs with diarrhea. The only gross change was a slight increase in cerebrospinal fluid. Histologic examination showed vascular lesions, demyelination, and malacia, most commonly located in the medulla oblongata, pons, and midbrain. The vascular lesions were degenerative and there were necrotic changes of the vessel walls and formation of periodic acid-Schiff positive perivascular eosinophilic droplets. Ultrastructurally, the swollen astrocytes around the vessels had many osmiophilic bodies in their cytoplasm with no limiting membrane. Demyelination and malacia, as well as vascular lesions, were considered to be the characteristic changes of cerebrospinal angiopathy. Our study suggests that E. coli may be a cause of cerebrospinal angiopathy.

A cerebrospinal angiopathy in pigs.

66 pigs from 52 premises have been found to be affected by a cerebrospinal angiopathy. In 64, symptoms first appeared in the 5 weeks following weaning. The lesions were characterised by thickening of the walls of the small arterioles of the central nervous system, swelling and degeneration of their medial cells, subendothelial hyaline deposits, and perivascular eosinophilic droplets. In a proportion of cases, similar vascular lesions were found in the tongue, pancreas, liver, small intestine and adnexa of the eye.