Subcutaneous nocardial abscesses in a patient with bullous pemphigoid during immunosuppressive therapy: report of a case and review of the Japanese literature

We describe a rare case of multiple, subcutaneous nocardial abscesses. A 67-year-old Japanese male with bullous pemphigoid was admitted to our hospital, and systemic prednisolone and double filtration plasmapheresis were administered. During the combination treatment, he noted a solitary subcutaneous nodule on the right upper arm. The lesions gradually increased in number and disseminated. The microbial diagnosis was thought to be a Nocardia species. Administration of combination chemotherapy with minocycline and diamino-diphenyl sulfone failed to eliminate the nodules completely, so he was treated with daily injection of amikacin sulfate into the nodules. The lesions dramatically responded to this therapy and resolved in four weeks.

Use of bisphosphonates for the treatment of bone metastasis in experimental animal models

Therapeutic effectiveness of bisphosphonates (BP) on bone metastases in patients with cancers including those of the breast and prostate has been well documented. However, there are still many important questions that remain unsolved or controversial. To obtain answers for these questions that are not readily addressed in a well-controlled manner in clinical studies, we have developed two animal models of bone metastasis (orthotopic and experimental). Using these models, we studied the effects of BP alone or in combination with anti-cancer agents on the metastasis of breast cancer to bone and visceral organs. In addition, we also determined the effects of BP on osteosclerotic metastases. We found that BP impaired the progression of bone metastases primarily through enhancing apoptosis in osteoclasts and breast cancer cells colonized in bone. In some situations, however, BP alone increased metastases in visceral organs including liver and adrenal glands. However, combination of BP with anti-cancer agents enhanced the suppression of tumour in both bone and visceral organs, leading to prolonged survival of tumour-bearing animals. Of potential importance, preventative administration of BP inhibited the development of eventual osteosclerotic bone metastases. These results suggest that BP exhibits diverse beneficial effects on osteolytic and osteoblastic bone metastasis and non-bone organ metastasis in breast cancer when administered appropriately. They also suggest that the animal models of bone metastasis described here allow us to produce clinically- relevant information that is useful for the design of optimal regimens of BP for the treatment of breast cancer patients with bone and visceral metastases.

Molecular mechanisms of expression of Lewis b antigen and other type I Lewis antigens in human colorectal cancer

Lewis b (Leb) antigens are gradiently expressed from the proximal to the distal colon, i.e., they are abundantly expressed in the proximal colon, but only faintly in the distal colon. In the distal colon, they begin to increase at the adenoma stage of cancer development and then increase with cancer progression. We aimed to clarify the molecular basis of Leb antigen expression in correlation with the expression of other type I Lewis antigens, such as Lewis a (Lea) and sialylated Lewis a (sLea), in colon cancer cells. Considering the Se genotype and the relative activities of the H and Se enzymes, the amounts of Leb antigens were proved to be determined by both the H and Se enzymes in noncancerous and cancerous colon tissues. But the Se enzyme made a much greater contribution to determining the Lebamounts than the H enzyme. In noncancerous colons, the Se enzyme were gradiently expressed in good correlation with the Leb expression, while the H enzyme was constantly expressed throughout the whole colon. In distal colon cancers, the H and Se enzymes were both significantly upregulated in comparison with in adjacent noncancerous tissues. In proximal colon cancers, expression of the H enzyme alone was highly augmented. The augmented expression of Leb antigens in distal colon cancers is caused mainly by upregulation of the Se enzyme and partly by the H enzymes, while it is caused by upregulation of the H enzyme alone in proximal colon cancers. The Se gene dosage profoundly influences the amounts of the Leb, Lea, and sLea antigens in whole colon tissues, regardless of whether they are noncancerous or cancerous tissues. It suggests that the Se enzyme competes with alpha2,3 sialyltransferase(s) and the Le enzyme for the type I acceptor substrates.

Molecular behavior of mutant Lewis enzymes in vivo

The expression of type-1 Lewis antigens on erythrocytes and in digestive organs is determined by a Lewis type alpha(1,3/1, 4)-fucosyltransferase (Lewis enzyme) encoded by the Fuc-TIII gene ( FUT3 gene; Lewis gene). We have classified the Lewis alleles in the Japanese population into four types, the wild-type allele ( Le ) and three mutated alleles, i.e., le1, which has missense mutations T59G and G508A, le2, which has T59G and T1067A, and le3, which has only T59G. Here we carried out an extensive study on the biological properties of the three mutant Lewis enzymes, the le1, le2, and le3 enzymes, using native tissues and obtained the following results. (1) In in vivo and in vitro experiments, the le1 and le2 enzymes were found to be susceptible to protease digestion probably because the one missense mutation in the catalytic domains, i.e., Gly170 to Ser in the le1 enzyme and Ile356 to Lys in the le2 enzyme, makes the three-dimensional structures of the enzymesunstable, while the le3 and wild-type Lewis enzymes wereresistant to protease digestion. (2) The le1 and le2 enzymes cannot synthesize type 1 Lewis antigens on either glycolipids or mucins. The le3 enzyme cannot synthesize Lewis-active glycolipids, which result in the Lewis antigen-negative phenotype of erythrocytes, while it can synthesize Lewis antigens on mucins in normal and cancerous colon tissues. The missense mutation, Leu20 to Arg, in the transmembrane domain reduces retention of the le3 enzyme in the Golgi membrane resulting in an apparent reduction of enzyme activity as revealed by the lack of Lewis antigen synthesis. (3) The Lewis gene dosage actually has effects in vivo on the amount of the Lewis enzyme, its activity, and finally the amounts of Lewis carbohydrate antigens. This is the first article that clearly demonstrates the gene dosage effects on the amount of the glycosyltransferase protein, its activity, and the amounts of carbohydrate products in vivo.

The aberrant expression of Lewis a antigen in intestinal metaplastic cells of gastric mucosa is caused by augmentation of Lewis enzyme expression

Immunohistochemical staining showed an aberrant expression of Le(a) antigen in the intestinal metaplastic glands of the gastric mucosa of secretors, as reported by others. In this study, we have demonstrated for the first time that the Lewis enzyme is well colocalized with Le(a) antigen, indicating that the Lewis enzyme is responsible for Le(a) antigen synthesis in the gastric mucosa. The staining intensity of the Lewis enzyme was much stronger in the cells with intestinal metaplasia than the cells without metaplasia, regardless of the secretor status. The amount of transcript of the Lewis gene was related to the degree of metaplasia; i.e., the more severe the metaplastic change was, the more abundantly the transcripts of the Lewis gene were expressed. This augmentation of the Lewis enzyme in metaplastic tissues was also confirmed by Western blotting analysis using a specific antibody against the Lewis enzyme. We conclude that intestinal metaplastic change of gastric mucosa is usually accompanied by a marked augmentation of the Lewis enzyme expression, which results in the enhanced expression of Le(a) antigens, particularly in secretors.

[Effectiveness of isoniazid inhalation in patients with endobronchial tuberculosis]

The clinical effectiveness of isoniazid (INH) inhalation was studied retrospectively in 34 patients with endobronchial tuberculosis. Diagnoses of endobronchial tuberculosis and assessments of bronchial stenosis were based on bronchoscopic examinations. We divided the patients into 2 groups: 13 who received systemic chemotherapy for lung tuberculosis only, and 21 who received systemic chemotherapy combined with INH inhalation (200 mg/day). No significant differences distinguished the groups with respect to duration of positive sputum culture or ESR normalization. However, a significant alleviation of bronchial stenosis and earlier reduction of respiratory symptoms were observed in the patients who received systemic chemotherapy with INH inhalation. We concluded that INH inhalation in addition to standard therapy for lung tuberculosis is effective in patients with endobronchial tuberculosis.

Morphologic characteristics of physiologically defined neurons in the cat trigeminal nucleus principalis

Although the principalis nucleus (Vp) contains trigeminothalamic and internuclear tract cells, the functional and morphologic differences between the two kinds of neurons have remained unsettled. The present study was aimed to address these problems by using the intracellular horseradish peroxidase injection technique in the cat. Of 20 neurons stained, 7 and 13 were located in the dorsomedial subnucleus (Vpd) and ventrolateral subnucleus (Vpv) of Vp, respectively. The Vpd neurons received input from the intraoral structures only but the Vpv neurons from the intraoral or facial structures. Nineteen neurons could be divided as class I and class II, based on the branching pattern of their stem axons. Class I (eight neurons) had an ascending stem axon without branching. Class II was divided into two subclasses (IIa and IIb). Class IIa (eight neurons) had an ascending stem axon from which branches were given off. Their branches formed a local-circuit restricted to the lower brainstem. Class IIb (three neurons) had a stem axon that formed the local-circuit only. The dendritic morphology was indistinguishable between different classes of neurons and between the subdivisions. Although the dendritic arborization pattern was governed by the location of the somata, it was suggested to be also important elements for determining primary afferent arborizations. In the brainstem nuclei, the jaw-closing motor nucleus received the highest density of projections from class II neurons with the receptive field involving the periodontal ligaments. The present study provides new findings that Vp neurons could be divided into three distinct populations and suggests that each population exerts a distinct function with respect to sensory discrimination, sensorimotor reflexes, or both.

Expression cloning and characterization of a novel murine alpha1, 3-fucosyltransferase, mFuc-TIX, that synthesizes the Lewis x (CD15) epitope in brain and kidney

The 3-fucosyl-N-acetyllactosamine (Lewis x, CD15, SSEA-1) carbohydrate epitope is widely distributed in many tissues and is developmentally expressed in some rodent and human tissues, i.e. brain and lung, and mouse early embryo. In such tissues, the Lewis x epitope is considered to be involved in cell-cell interactions. We isolated a novel mouse alpha1,3-fucosyltransferase gene, named mFuc-TIX, from an adult mouse brain cDNA library using the expression cloning method. On flow cytometric analysis, Namalwa cells transfected stably with the mFuc-TIX gene showed a marked increase in Lewis x epitopes but not sialyl Lewis x epitopes. As seen experiments involving oligosaccharides as acceptor substrates, mFuc-TIX transfers a fucose to lacto-N-neotetraose but not to either alpha2,3-sialyl lacto-N-neotetraose or lacto-N-tetraose. The substrate specificity of mFuc-TIX was similar to that of mouse myeloid-type alpha1,3-fucosyltransferase (mFuc-TIV). The deduced amino acid sequence of mFuc-TIX, consisting of 359 residues, indicated a type II membrane protein and shows low degrees of homology to the previously cloned alpha1,3-fucosyltransferases, i.e. mFuc-TIV (48.4%), mouse Fuc-TVII (39.1%), and human Fuc-TIII (43.0%), at the amino acid sequence level. A phylogenetic tree of the alpha1, 3-fucosyltransferases constructed by the neighbor-joining method showed that mFuc-TIX is quite distant from the other alpha1, 3-fucosyltransferases. Thus, mFuc-TIX does not belong to any subfamilies of known alpha1,3Fuc-Ts. The mFuc-TIX transcript was mainly detected in brain and kidney with the Northern blotting and competitive reverse transcription-polymerase chain reaction methods, whereas the mFuc-TIV transcript was not detected in brain with these methods. On in situ hybridization, the mFuc-TIX transcript was detected in neuronal cells but not in the glial cells including astrocytes. These results strongly indicated that mFuc-TIX participates in the Lewis x synthesis in neurons of the brain and may be developmentally regulated.

Constitutive up-regulation of integrin-mediated adhesion of tumor-infiltrating lymphocytes to osteoblasts and bone marrow-derived stromal cells

Tumor-reactive T cells, known as tumor-infiltrating lymphocyte(TIL)s are known to infiltrate various tumors. Although TILs exert cytotoxic activities against tumor cells, only a small percentage of tumors usually contain TILs that specifically react to tumor antigens. Because the exact role of these lymphocytes is unclear, we investigated the mechanisms of migration and adhesion of TILs to bone metastatic tumors, particularly to osteoblasts and bone marrow-derived stromal cell(BMSC)s. Histopathological examination showed that most TILs in secondary bone metastatic tumors (from primary tumors in the lung or breast) were found in the supporting tissue stroma between the bone and tumor mass. Cultured TILs (obtained from breast tumors) adhered spontaneously to osteoblasts and BMSCs (obtained from patients with osteoarthritis) without exogenous stimulation. Adhesion was further enhanced by chemokines macrophage inflammatory protein (MIP)-1alpha and MIP-1beta. TILs highly expressed activation antigens CD25 and CD69. A spontaneous activation of an integrin, lymphocyte function-associated antigen-1 (LFA-1), was also detected on TILs. TILs produced high concentrations of MIP-1alpha and MIP-1beta and spontaneous polymerization of cytoskeletal F-actin was observed in these cells. Adhesion of TILs to osteoblasts and BMSCs via LFA-1 and very late antigen-4 was associated with the production of osteoclastogen interleukin 6 by the latter cells. Our results indicate that integrins on TILs are activated in an autocrine manner by MIP-1alpha and MIP-1beta, and that treatment with the chemokines increases the binding of TILs on osteoblasts and stromal cells via a mechanism involving intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 as targets for the integrin. Our data also indicated that interactions between TILs and osteoblasts/stromal cells lead to the secretion by the latter of the osteoclastogenic cytokine interleukin 6.

The aberrant expression of Lewis a antigen in intestinal metaplastic cells of gastric mucosa is caused by augmentation of Lewis enzyme expression

Immunohistochemical staining showed an aberrant expression of Le(a) antigen in the intestinal metaplastic glands of the gastric mucosa of secretors, as reported by others. In this study, we have demonstrated for the first time that the Lewis enzyme is well colocalized with Le(a) antigen, indicating that the Lewis enzyme is responsible for Le(a) antigen synthesis in the gastric mucosa. The staining intensity of the Lewis enzyme was much stronger in the cells with intestinal metaplasia than the cells without metaplasia, regardless of the secretor status. The amount of transcript of the Lewis gene was related to the degree of metaplasia; i.e., the more severe the metaplastic change was, the more abundantly the transcripts of the Lewis gene were expressed. This augmentation of the Lewis enzyme in metaplastic tissues was also confirmed by Western blotting analysis using a specific antibody against the Lewis enzyme. We conclude that intestinal metaplastic change of gastric mucosa is usually accompanied by a marked augmentation of the Lewis enzyme expression, which results in the enhanced expression of Le(a) antigens, particularly in secretors.

Comparison of the effect of bezafibrate on improvement of atherogenic lipoproteins in Japanese familial combined hyperlipidemic patients with or without impaired glucose tolerance

The effect of bezafibrate on plasma lipoproteins was investigated in Japanese familial combined hyperlipidemic patients with or without an impaired glucose tolerance accompanied by a low-density lipoprotein subclass, with the major gradient gel peak at a particle diameter of less than 25.5 nm. Bezafibrate treatment at a dose of 400 mg/d for 12 weeks produced an antiatherogenic effect on lipoprotein profiles, as reflected by a decrease in plasma triglyceride levels, an increase in plasma high-density lipoprotein-cholesterol levels, induction of the large-size subclass of low-density lipoprotein, and disappearance of intermediate-density lipoproteins. The plasma total and low-density lipoprotein-cholesterol-lowering effect of bezafibrate was significant in patients without impaired glucose tolerance but was not significant in patients with impaired glucose tolerance. Bezafibrate increased lipoprotein lipase activity and decreased the activity of cholesteryl ester transfer protein, both in patients with or without impaired glucose tolerance. There was no difference in the distribution of signal peptide insertion/deletion or Xbal polymorphisms of the apolipoprotein B gene in patients with or without impaired glucose tolerance. Mechanisms other than lipoprotein lipase, cholesteryl ester transfer protein activities, and an apolipoprotein B gene polymorphism may be responsible for the resistance to lowering of plasma total and low-density lipoprotein cholesterol levels with bezafibrate treatment in familial combined hyperlipidemic patients with impaired glucose tolerance.

Recovery of pancreatic beta-cell function in hemochromatosis: combined treatment with recombinant human erythropoietin and phlebotomy

A patient with diabetes mellitus caused by secondary hemochromatosis was treated using recombinant human erythropoietin and phlebotomy. A total of 12 g of iron had been infused in the patient because of iron deficiency anemia. Blood glucose level was 17.3 mmol/L, and hemoglobin A1c level was 9.0% at admission. He was treated using phlebotomy (400 mL per week), along with subcutaneous injection of 3,000 U of recombinant human erythropoietin three times a week. After approximately 100 days, a total of 5,500 mL of blood (2.75 g iron) could be removed. Serum ferritin level decreased from 10,000 micrograms/L to 4,807 micrograms/L. Fasting and maximum serum C-peptide immunoreactivity values during 100-g oral glucose tolerance tests were improved from 0.14 nmol/L to 0.42 nmol/L and from 1.84 nmol/L to 2.61 nmol/L, respectively. This case suggests that pancreatic beta-cell recovers in diabetes caused by hemochromatosis by reducing iron overload during a short period.

Morphological study of bovine pregnant corpus luteum cells

The bovine pregnant corpus luteum was examined morphologically, to clarify the appearance and properties of the intramitochondrial bodies (IMB) in mitochondria of the large luteum cell (LLC). The incidence and diameter of the IMB (200-900 nm) showed a tendency to increase with the advance of pregnancy. Histochemically, the IMB reacted positively with protein, and immunohistochemically, they reacted IMB with 11 alpha-hydroxyprogesterone-1-11 succinyl-bovine serum albumin (P-BSA). The IMB seemed to combine with protein, and these granules did not undergo exocytosis. The cytoplasm of LLC contained another type of small electron-dense granules that were 150-200 nm in diameter, had an orifice for secretion, and reacted with relaxin. Small luteum cells (SLC) revealed crystalline-like inclusions. It is suggested that these inclusion cells participate in the synthesis of steroids.

Inhibitory effects of caffeine on Ca2+ influx and histamine secretion independent of cAMP in rat peritoneal mast cells

1. Caffeine did not evoke Ca2+ mobilization and histamine secretion. 2. Caffeine, as well as other methylxanthines but not forskolin or 8 bromo-cAMP, inhibited Ca2+ responses from compound 48/80. 3. Evoked histamine secretion was severely reduced by caffeine but not by cAMP analogs. 4. In beta-escin-permeabilized cells, caffeine did not affect resting and IP3-stimulated 45Ca2+ release, but it inhibited Ca(2+)-induced histamine secretion. 5. These results indicate that caffeine inhibits Ca2+ influx and Ca2+ efficacy in the secretory apparatus independent of cAMP, resulting in the inhibition of secretagogs-evoked histamine secretion from rat mast cells.

Inositol 1,4,5-trisphosphate- and caffeine-sensitive Ca(2+)-storing organelle in bovine adrenal chromaffin cells

The uptake and release properties of Ca2+ by several subcellular fractions of the bovine adrenal medulla were investigated. Investigation by the 45Ca2+ tracer method showed that permeabilized cells and the fractions of mitochondria (MT) and microsomes (MC) caused ATP-dependent Ca2+ uptake in a Ca2+ concentration-dependent manner (pCa 8-4), whereas permeabilized cells and the fractions of secretory granules (SG) were able to accumulate a significant amount of Ca2+ even in the absence of ATP, which was completed by the addition of hexokinase and glucose. In these organelle fractions, Ca2+ uptake in the presence of ATP at pCa 7 and pCa 5.8 was well-correlated with the activity of the NADPH cytochrome c reductase (marker enzyme for the endoplasmic reticulum) and cytochrome c oxidase (marker enzyme for mitochondria), respectively. As detected by Fura-2 ratiometry, both inositol 1,4,5-trisphosphate (IP3) and caffeine caused concentration-dependent Ca2+ releases from permeabilized cells and MC, but not from MT and SG. In an ATP-depleted condition, homogenates still took up a significant amount of Ca2+ but was not able to respond to IP3 and caffeine. These results suggest that the endoplasmic reticulum is a major Ca(2+)-storing organelle, which releases Ca2+ in response to IP3 and caffeine in bovine adrenal chromaffin cells.

Hypertriglyceridemia, but not hypercholesterolemia, is associated with the alterations of fibrinolytic system

Derangements of the blood coagulation-fibrinolytic system are thought to be associated with the development of cardiovascular disease. Previous studies have identified the alterations in patients with advanced atherosclerosis, however, studies on subjects without apparent cardiovascular complications are scarce. To evaluate the potential risk of thrombosis, we examined the serum lipid levels and fibrinolytic parameters in 54 subjects of different types of primary hyperlipoproteinemia (HL) and 18 normolipidemic controls. Plasma tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) antigen levels were significantly higher in type IV HL than in the controls. Serum triglyceride concentrations were correlated with t-PA (r = 0.537, p < 0.01) and PAI-1 (r = 0.249, p < 0.05) antigen levels, while serum cholesterol levels did not. The current study demonstrated that hypertriglyceridemia, but not hypercholesterolemia, is associated with the alterations of fibrinolytic system.

Effects of bisphosphonate (pamidronate) on bone resorption resulting from metastasis of a squamous cell carcinoma: report of an autopsy case and evaluation of bone resorbing activity in an experimental animal model

PURPOSE

This study evaluated the ability of bisphosphonate to prevent bone resorption induced by metastatic tumor cells.

MATERIALS AND METHODS

Autopsy specimens of a bone metastasis from a woman with a primary squamous cell carcinoma of the tongue who developed multiple osteolytic lesions and hypercalcemia and was treated with pamidronate were studied histologically, histochemically, and ultrastructurally. In an animal experiment, cultured tumor cells (1 x 10(5)) obtained from a metastatic submandibular lymph node in the same patient were injected in the left ventricle of nude mice, and a resulting metastatic bone lesion was studied histologically and histochemically.

RESULTS

In the autopsy specimens, despite the presence of many resorption lacunae on bone surface, only a few small tartrate-resistant acid phosphatase (TRAPase)-positive cells were observed, and most of them were stained weakly and detached from the bone surface. In the animal experiment, 1 of 10 animals (10%) formed osteolytic bone metastasis, and many TRAPase-positive cells were observed histochemically.

CONCLUSIONS

Biphosphonate inhibits bone resorption induced by tumor, possibly by decreasing the number of osteoclasts and inhibiting their function.

An experimental model of bone metastasis by human lung cancer cells: the role of parathyroid hormone-related protein in bone metastasis

In the formation of bone metastasis, osteoclastic bone resorption is necessary before the expansion of tumor cells from bone marrow to bone, and several cytokines, which possess osteoclast-stimulating activity, could be involved in this step. In this paper, we describe a bone metastasis model in nude mice using human lung squamous cell carcinoma-derived cells (HARA), in which the parathyroid hormone-related protein (PTHrP) gene, one of the most potent osteoclast-activating factors, is strongly expressed. The injection of HARA cells (1 x 10(5)) into the left cardiac ventricle resulted in tumor colonies exclusively in the skeletal system at 4 and/or 8 weeks after inoculation. An anti-PTHrP antibody injected via a tail vein reduced the incidence of bone metastases, number of tumor colonies, and tumor volume after the inoculation of HARA cells. The injection of another line of human lung squamous cell carcinoma-derived cells (QG-56), in which the PTHrP gene is not expressed, resulted in no bone metastasis. These findings suggest that PTHrP plays an important role in the formation of bone metastasis.

Lipoprotein(a) is an independent risk factor for multiple cerebral infarctions

In an attempt to ascertain whether Lp(a) is a risk factor for multiple cerebral infarctions (MCI), we have studied 83 patients with proven MCI and 39 subjects without MCI by computed tomography (CT). Seventy-one patients with non-insulin-dependent diabetes mellitus (NIDDM) were included: 52 with and 19 without MCI. Serum Lp(a) levels were significantly higher in patients with MCI than in subjects without MCI. There were no differences in serum Lp(a) levels between NIDDM and non-diabetic patients with MCI. The logistic regression analysis revealed that Lp(a) and hypertension were independent risk factors for the cerebral event. The current study demonstrated that Lp(a) and hypertension are significant risk factors for multiple cerebral infarctions.

Immunohistochemical analysis of the endocrine cells in the pancreatic islets of cattle

The distribution of endocrine cells and the areas of islets in the bovine pancreas were investigated by immunohistochemical methods. The islets in the A-region, which consisted of the left lobe, the ventral portion of the body, and the ventral and distal portions of the right lobe, contained a central core of insulin-containing (B-) cells surrounded by glucagon containing (A-) cells, a few somatostatin-containing (D-) cells and sporadic pancreatic polypeptide-containing (PP-) cells. The islets in the B-region, which consisted of the uncinate process, and the dorsal and proximal portions of the body and the right lobe, contained a central mass of B-cells, and peripheral cells which were predominantly PP-cells with a few D-cells but no A-cells. The areas of islets in the B-region were small as compared with those in the A-region. From these findings it is suggested that A- and PP-cells have a complementary relationship to one another. In view of this hypothesis, two types of islet, A-cell-rich and PP-cell-rich islets, were identified. The A-region contained A-cell-rich islets derived from the dorsal pancreatic primordium, while the B-region contained PP-cell-rich islets that originated from the ventral primordium. In the bovine pancreas, the areas containing PP-cell-rich islets are greater than those in previously examined species.

Inhibitory effects of bisphosphonate (YM175) on bone resorption induced by a metastatic bone tumor

The effects of a third-generation bisphosphonate, YM175 (disodium dihydrogen (cycloheptylamino)-methylene-1,1-bisphosphonate), on bone resorption induced by a metastatic human melanoma cell line (A375) were investigated morphologically using an experimental model of bone metastases in nude mice. An injection of A375 in the left cardiac ventricle produced multiple osteolytic lesions. Then, 4 weeks after the cell injection, we administrated YM175 (1 mg/kg) intravenously once and sacrificed the animals 3 days later. On histochemical observation, there was a layer of stromal cells with numerous mononuclear and multinucleated tartrate-resistant acid phosphatase (TRAPase)-positive cells in the untreated control group. In contrast, this layer was extensively reduced in most areas, and only a few TRAPase-positive cells were seen around tumor nests and on the bone surface in the experimental group. Most of the TRAPase-positive cells were stained only weakly and/or homogeneously, and there was little evidence of cell polarity. Some of them were vacuolated. Ultrastructurally, they were round and devoid of ruffled borders and clear zones. The findings suggest that YM175 decreases the number and activity of osteoclasts. In addition, a few showed the morphology of cell death, which seemed to be one of the reasons leading to the decrease of osteoclasts. There was no substantial change in the morphological relationships or ultrastructure of osteoclast precursor cells, stromal cells, extracellular matrices, and tumor cells between the experimental and the control groups. In the experimental group, the distribution of extracellular matrices (heparan sulfate proteoglycan and fibronectin) was less conspicuous, but the localization of osteotropic cytokines (interleukin-6 and prostaglandin E2) was essentially similar to that of the control group. The cause leading to the decrease of osteoclast precursor cells remains to be clarified. In conclusion, YM175 inhibits bone resorption induced by tumor, by decreasing the activity of mature osteoclasts and possibly affecting the production of osteoclast precursor cells.

Microvascular changes during the development of follicles in bovine ovaries: a study of corrosion casts by scanning electron microscopy

Microvascular changes during the development of follicles in bovine ovaries were studied by scanning electron microscopy of corrosion casts. A clear vascular plexus of ovarian follicles appeared at the stage when secondary follicles were 200-400 microns in diameter. The plexus consisted initially of a thin, roughly structured and single-layered capillary network. During follicular development, the microvascular architecture of antral follicles was arranged as two independent vascular plexuses. The inner plexus, which received a spiral arteriole, consisted of a dense sinusoidal capillary network with an arterial and a venous layer; it functioned as an independent microcirculatory unit. The inner plexus developed from the capillary plexus of the theca interna of the secondary follicles. The outer plexus, which anastomosed with several stromal capillaries, consisted of a thin, coarse and basket-like capillary plexus. The outer plexus was formed from the stromal capillary plexus as a consequence of the rapid enlargement of developing antral follicles.

Malignant schwannoma arising in patients with von Recklinghausen's disease: report of two cases and the comparison of mast cells between benign and malignant portions

We described two cases of malignant schwannoma arising in patients with von Recklinghausen's disease and examined the mast cells infiltrated into histologic sections. One of the two cases histologically revealed apparent mast cell infiltration in some areas of malignant schwannoma as well as in the benign neurofibroma. The malignant lesion demonstrated significantly increased percentages of degranulated mast cells over the benign lesion using FITC-avidin staining. In an electron microscopic study, mast cells in the malignant lesion displayed empty granules, piecemeal degranulation, and canaliculi structures suggesting activation. These findings were not observed in the benign lesion. The other patient histologically showed no mast cells in the malignant lesion, although the benign neurofibroma in the patient disclosed numerous mast cells. The first patient had neither recurrence nor distant metastasis. On the other hand, the second patient without mast cells in the histology had multiple distant metastases.