Large scale replication analysis of loci associated with lipid concentrations in a Japanese population

BACKGROUND

Recent genome wide association studies discovered seven novel loci that influence plasma concentrations of triglycerides, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in Europeans. To date, large scale replication studies using populations with known differences in genome-wide linkage disequilibrium (LD) pattern have not been undertaken.

METHODS

To address this issue, we tested associations between single nucleotide polymorphisms (SNPs) within the seven novel loci and plasma lipid profiles in 21 010 Japanese individuals.

RESULTS

Multiple linear regression analyses showed that the rs3812316 in MLXIPL was strongly associated with triglyceride concentrations (p approximately 3.0x10(-11), 7.1 mg/dl decrease per minor C allele) and that rs599839 in CELSR2/PSRC1/SORT1 was strongly associated with LDL cholesterol concentrations (p approximately 3.1x10(-11), 4.7 mg/dl decrease per minor G allele) in the Japanese population. SNPs near ANGPTL3, TRIB1 and GALNT2 showed evidence for associations with triglyceride concentrations (3.6x10(-6)<p<5.1x10(-5)). SNP near TRIB1 showed association with LDL cholesterol concentrations (p approximately 1.2x10(-5)). On the other hand, SNPs in NCAN/CILP2/PBX4 and MVK/MMAB were not associated with any plasma lipid profiles in the Japanese population. Ethnic differences in LD pattern would explain the lack of association between these two loci and plasma lipid concentrations in the Japanese population.

CONCLUSION

Associations between the novel loci and plasma lipid concentrations were generally conserved in the Japanese population, with the exception of NCAN/CILP2/PBX4 and MVK/MMAB.

Ovarian carcinoid exhibiting double function

A case of a 58-year-old woman with ovarian carcinoid exhibiting double function is reported. She had suffered from constipation and hirsutism before surgery. Pathological examination revealed that many carcinoid tumor cells were immunohistochemically positive for peptide YY, which inhibits intestinal motility and many peripheral steroid cells. After surgery the patient recovered from constipation immediately. Although the serum level of testosterone also immediately decreased, hirsutism remained for about 2 years. These clinical manifestations are considered to be due to peptide hormone-producing tumor parenchymal cells and testosterone-producing functioning stromal cells. This is the first report of clinically manifested double-functioning ovarian carcinoid; one function is due to tumor cells themselves and another function is due to stromal cells.

Gene expression profiles in Ciona intestinalis tailbud embryos

A set of 3423 expressed sequence tags derived from the Ciona intestinalis tailbud embryos was categorized into 1213 independent clusters. When compared with DNA Data Bank of Japan database, 502 clusters of them showed significant matches to reported proteins with distinct function, whereas 184 lacked sufficient information to be categorized (including reported proteins with undefined function) and 527 had no significant similarities to known proteins. Sequence similarity analyses of the 502 clusters in relation to the biosynthetic function, as well as the structure of the message population at this stage, demonstrated that 390 of them were associated with functions that many kinds of cells use, 85 with cell-cell communication and 27 with transcription factors and other gene regulatory proteins. All of the 1213 clusters were subjected to whole-mount in situ hybridization to analyze the gene expression profiles at this stage. A total of 387 clusters showed expression specific to a certain tissue or organ; 149 showed epidermis-specific expression; 34 were specific to the nervous system; 29 to endoderm; 112 to mesenchyme; 32 to notochord; and 31 to muscle. Many genes were also specifically expressed in multiple tissues. The study also highlighted characteristic gene expression profiles dependent on the tissues. In addition, several genes showed intriguing expression patterns that have not been reported previously; for example, four genes were expressed specifically in the nerve cord cells and one gene was expressed only in the posterior part of muscle cells.

This study provides molecular markers for each of the tissues and/or organs that constitutes the Ciona tailbud embryo. The sequence information will also be used for further genome scientific approach to explore molecular mechanisms involved in the formation of one of the most primitive chordate body plans.

Role of hydrogen peroxide in antitumor activity induction by sodium 5,6-benzylidene-L-ascorbate

Role of hydrogen peroxide (H2O2) in the induction of antitumor activity against chemically-induced rat hepatocellular carcinoma by sodium 5,6-benzylidene-L-ascorbate (SBA) was investigated. ESR spectroscopy demonstrated that rat liver homogenate of cancerous tissue significantly enhanced the radical intensity of SBA more potently than that of precancerous or normal tissue. The peroxyoxalate chemiluminescence method demonstrated that SBA significantly enhanced the production of H2O2-derived chemiluminescence intensity in the liver homogenates, and the effect of SBA was greater in cancerous tissue than in precancerous or normal tissue. Addition of ascorbic acid, a degradation product of SBA, showed similar but slightly weaker stimulation effects. These data suggest that antitumor activity of SBA in vivo might, at least in part, be due to H2O2 production.

Ameloblastic fibrosarcoma arising de novo in the maxilla

An ameloblastic fibrosarcoma (AFS) arising in the maxilla of a 14-year-old male is described. The tumor originated from the alveolar bone of the right maxilla with no apparent history of pre-existing lesion. Histologically, the lesion was composed of benign-appearing epithelial islands and strands scattered within an exceedingly cellular mass of mesenchymal tissue comprising a large number of stellate-and spindle-shaped fibroblast-like cells with marked pleomorphism. Occasional cementum-like calcification was also noted. Immunohistochemically, the neoplastic mesenchymal cells were positive only for vimentin, whereas the ameloblast-like epithelial component showed a distinctly positive reaction for wide-spectrum keratin and squamous cytokeratin. Clinicopathological features of the current case, as well as previously reported examples of AFS originating from the maxilla, are briefly discussed.

DNA-based diagnostics in the study of heritable and acquired disorders

Recent advances in molecular biology techniques have made DNA diagnostics a reality. A major advance was the development of the polymerase chain reaction, which allows the direct analysis of a region of a known gene from minute quantities of template DNA. The DNA can even be isolated from such sources as saliva, hair roots, microscope slides, paraffin-embedded tissue, and clinical swabs, in addition to blood and biopsy material. Another major improvement is the development of automated procedures suitable for robotic stations. Together these improvements make DNA analysis an important part of diagnostic procedures in studying the etiology of diseases.

Immunohistochemical analysis of EGF in epiphyseal growth plate from normal, hypophysectomized, and growth hormone-treated hypophysectomized rats

Epiphyseal growth plate cartilages from the proximal tibia of normal, hypophysectomized, and growth hormone (GH)-treated hypophysectomized rats were subjected to immunohistochemistry for detection of epidermal growth factor (EGF). In the normal growth plate, EGF was distributed mainly in the proliferative zone. Hypophysectomy resulted in considerable atrophy of the chondrocytes and the cartilage matrix (a decreased number of mature-type chondrocytes and a decreased ratio of proliferating to hypertrophic chondrocytes) and a significant diminution of EGF immunoreactivity. Treatment with GH reversed these effects of hypophysectomy, causing an increased thickness of the growth plate and EGF-reactive sites in all chondrocyte layers. The most intense immunostaining for EGF, however, was frequently seen in the nuclei of chondrocytes with flattened appearance. It appears that EGF could be incorporated or synthesized in chondrocytes having marked mitogenic activity. The present results, taken with previous data on EGF involvement in growth of cartilaginous tissue in vivo and in vitro, strongly suggest that EGF-immunoreactive chondrocytes are involved in cartilage proliferation and growth under the specific influence of GH.

Computer-aided image analysis applied to immunogold-silver staining: evaluation of proliferating cell nuclear antigen (PCNA)-reactive sites in paraffin sections

Feasibility of the combination of the immunogold-silver staining method (IGSS) and computer-aided image analysis was assessed for the detection of antigen in an immunostained, paraffin-embedded section. Using low-temperature IGSS, we stained a specimen of human oral squamous cell carcinoma with a monoclonal antibody, PC 10, against a proliferating cell nuclear antigen (PCNA/cyclin), and the section was analyzed by ACAS 570 interactive laser cytometry. The PCNA-positive cells, exhibiting a heteromorphic texture, were contrasted by the dark staining of their nuclei, but showed heterogeneity in staining intensity from cell to cell. Using a conventional microscope light source rather than a laser, and by employing the COMPLEMENT DATA program (which permits inversion of the data values) installed in the ACAS 570 software system, we were able to obtain a 'complemental image' which replicated the real immunohisto-morphology. Approximately 30-35 cells from three different areas in the same section were selected by DEFINE CELL and MARK AREA programs, and quantitative image analysis was performed in terms of cell integrated value, area, perimeter, and shape factor indicated in histogram form. The combined utilization of IGSS with computer-aided image analysis was demonstrated to offer a crucial advantage for the quantitative assessment of immunostained sections.

Increased expression of type VI collagen genes in drug-induced gingival enlargement

Fibrotic gingival enlargements induced by phenytoin or nifedipine were examined with special reference to type VI collagen expression. Immunolocalization studies showed abnormal accumulation of type VI collagen around the collagen fiber bundles in the fibrotic gingival enlargements. Examination of total RNA extracted from fibroblasts and tissues of enlarged gingivae demonstrated increased type VI collagen steady-state mRNA levels. These results suggest that excessive deposition of type VI collagen in drug-induced gingival enlargement is attributed to increased expression of the collagen genes.

Epidermoid carcinoma originating from the gingival sulcus

This paper describes a case of epidermoid carcinoma originating from the gingival sulcular epithelium with proper plane of histopathology. Relevant articles on carcinoma of gingiva are briefly reviewed, and the necessity for early diagnosis of this lesion is emphasised.

Immunohistochemical detection of sialyl Le(x) antigen on mucosal Langerhans cells of human oral mucosa following neuraminidase pretreatment

Histochemical assessment of selected carbohydrate sequences on Langerhans cells of human oral mucosa was made by combined use of enzyme digestion and immunostaining with monoclonal antibodies against specific carbohydrate structures. In both frozen sections and epithelial sheets without the enzyme pretreatment, mucosal Langerhans cells, identified by positive staining with anti-CD1a and HLA-DR antibodies, did not express any carbohydrate antigens on their surface. In contrast, following neuraminidase pretreatment of both types of material, the fucosylated type 2 chain (Le(x)) became detectable on Langerhans cells, indicating that sialic acid is the terminal residue of this sequence. Other enzymes were ineffective in this apparent unmasking, and the staining patterns of the other related carbohydrate sequences (Le(y)+, Le(a), Le(b)) remained unaffected by pretreatment with any of the enzymes used. These findings suggest that the mucosal Langerhans cells possess a unique carbohydrate chain, the sialyl fucosylated type 2 sequence (sialyl Le(x) antigen).

Immunohistochemical demonstration of epidermal growth factor in chondrocytes of mouse femur epiphyseal plate

The distribution of epidermal growth factor (EGF) has been studied immunohistochemically in chondrocytes of femur epiphyseal plate cartilage from adult mice. The chondrocytes of the resting and proliferating zones reacted positively, while those of maturing and calcifying zones showed a relatively weak reaction. The immunoreaction was observed over both the cytoplasm and nuclei of resting and proliferating chondrocytes and was prominent in the proliferating chondrocytes. These findings, taken together with the suggested synergistic action of EGF with other growth factors, raise the possibility that chondrocytes, particularly in the proliferating zone, participate in a regulatory mechanism by EGF on cell division and growth in the epiphyseal plate cartilage.

Ameloblastoma arising in calcifying odontogenic cyst. Report of a case

An unusual case of an ameloblastoma with adenoid-cribriform features arising in calcifying odontogenic cyst is reported. A possible relationship between this peculiar variant of calcifying odontogenic cyst and a conventional ameloblastoma is discussed.

Cylindrical cell papilloma of the nasal cavity and paranasal sinuses. A histochemical and cytochemical study

A cylindrical cell papilloma occurring in the sino-nasal mucosa of a 61-year-old woman was studied histochemically at both light and electron microscopic levels. The cylindrical cells demonstrated distended intracytoplasmic microcysts with numerous microvillous projections on the apical cell membrane. The retained mucosubstance in the cystic spaces stained intensely with HID-TCH-SP sequence and showed no apparent communication with the extracellular space. These findings indicate that the cylindrical cells may be of mucous-secreting cell derivation, being derived from cells possessing abnormal and/or failed secretory function. The property of sulfated mucin in the 'cylindric' intracytoplasmic cysts is suggested to be the result of endodermal displacement or metaplasia of the Schneiderian epithelium.

Increased gene expression of matrix metalloproteinase-3 (stromelysin) in skin fibroblasts from patients with severe recessive dystrophic epidermolysis bullosa

Gene expression of matrix metalloproteinase 3 (MMP-3 = stromelysin) was examined in the skin fibroblasts obtained from patients with severe recessive dystrophic epidermolysis bullosa (RDEB). Steady-state mRNA level of MMP-3 was selectively increased in the unstimulated RDEB cells by a post-transcriptional mechanism. A parallel study on the susceptibility of type VII collagen to MMPs revealed that this type of collagen is degraded by MMP-3, but not by MMP-1 (collagenase). These data suggest that MMP-3 may play an important role in the blister formation fo the skin in RDEB patients by the degradation of anchoring fibrils consisting of type VII collagen.

Light and electron microscopic demonstration of wheat germ agglutinin binding in the pericellular matrix of rat mandibular condylar cartilage

Binding of wheat germ agglutinin to rat mandibular condylar cartilage was investigated with the avidin-biotin peroxidase complex. Binding sites were observed in the pericellular matrix of the hypertrophic cell zone. Two distinct patterns were identified: one showed binding to the pericellular matrix without apparent contour; in the other binding was confined to the matrix but with conspicuous condensation forming a pericellular rim. The first binding pattern was seen particularly in the upper part of the hypertrophic cell zone adjoining the mature cell zone; the second was localized in the lower part of this zone adjacent to the site of endochondral calcification. The binding sites in the pericellular matrix are assumed to be NANA and/or GlcNAc in view of the sugar specificity of this lectin. The presence of these binding sites in this region may be due to a structural alteration or modification of proteoglycans in the course of preparation for endochondral calcification.

Immunocytochemical detection of S-100 protein in rat mandibular condylar cartilage

Light and electron microscopic immunocytochemistry was used to localize S-100 protein. It was demonstrated in chondrocytes of the proliferative and hypertrophic zones but none could be found in the fibrous articular layer. The staining intensity for S-100 protein was stronger in the hypertrophic cells than in chondrocytes from the proliferative zone. Ultrastructurally, immunoreactive gold particles were detected in the cytosolic region, closely apposed to the profiles of endoplasmic reticulum with occasional dense aggregations. A few gold particles were seen on the nuclear chromatin and on condensing vacuoles of Golgi complexes. Because of the calcium-binding and possibly fatty acid-binding properties of the protein molecule, the immunocytochemical expression of S-100 protein in the chondrocytes may be involved in cartilage cell differentiation, metabolism and mineralization.

An ameloblastoma-like neoplasm of the buccal mucosa. Report of a case

A case of an unusual neoplasm of the buccal mucosa nearly identical to an ameloblastoma is reported. The tumor probably arose from the overlying squamous epithelium in the vicinity of the parotid duct.

[Comparative WGA-lectin histochemical study on the mandibular condylar cartilage from normal and low phosphate-vitamin D deficient rats]

Mandibular condylar cartilage from normal and low phosphate-vitamin D deficient rats were investigated by lectin histochemistry utilizing wheat germ agglutinin (WGA). We obtained the following results: 1) The cartilage from low phosphate-vitamin D deficient animals consisted predominantly of hypertrophic chondrocytes with abundant extracellular matrix. 2) The territorial matrix of the hypertrophic cell zone of normal cartilage was intensely labelled with WGA, whereas the binding affinity of this region in low phosphate-vitamin D deficient animals was significantly diminished. 3) Compared to normal cartilage, WGA binding sites were demonstrated in the inter-territorial matrix of low phosphate-vitamin D deficient animals to a moderate degree. 4) Abolishment of the territorial WGA binding affinity in low phosphate-vitamin D deficient animals was presumed to indicate the accumulation of chondroitin sulfate which is believed to be a strong chelator of calcium ion.

Calcifying odontogenic cyst immunohistochemical detection of keratin and involucrin in cyst wall

Calcifying odontogenic cysts (COC) were immunohistochemically described using different keratin proteins and involucrin as well as histopathology. The cystic lining epithelium was composed of calcifying, keratinizing, squamous, and columnar epithelial cells, and included calcified masses of irregular shape and various size as well as ghost cells. Calcifying epithelium gave negative or only trace staining for keratins detected with low molecular keratin (PKK1), but were regularly positive with high molecular keratin (KL1) and polyclonal antibody for keratin (TK). They were occasionally positive for involucrin. The cells located in the periphery of the calcified masses had a particular abundance of high molecular weight and total keratins (KL1 and TK). Calcified bodies and ghost cells were devoid of any immunoreactivity. Squamous epithelium was relatively similar to that of normal squamous cell epithelium in the oral mucosa. It were most commonly found in columnar cystic epithelial cells which displayed intense staining with all immunoreagents. It is postulated that such epithelial cells may have a strong potentiality to transform into ghost cells or to undergo metaplasia. They may develop altered synthesis of homogenous acellular materials and finally become transformed into calcifying epithelium containing dystrophic calcified masses.

Binding of wheat germ agglutinin in the matrix of rat tracheal cartilage

The binding of wheat germ agglutinin (WGA) to the extracellular matrix of rat tracheal cartilage was studied at both the light and electron microscopic levels. The detection of binding sites was accomplished by a postembedment method using the direct fluorescence technique for light microscopy and the avidin-biotin bridging system for electron microscopy. Distinct fluorescence was observed in the pericellular region of chondrocytes, and this fluorescence was completely removed after treatment with 4 M guanidine hydrochloride. By electron microscopy, the reaction products as found in the pericellular region were not observed in the interterritorial collagenous matrix, confirming a similar distribution as found by fluorescence microscopy. These results show that WGA-binding sites are present in pericellular matrical substances, which are known to be rich in proteoglycan and glycosaminoglycan complexes and which exhibit similar staining with antibodies to proteoglycans or with cationic dyes. As WGA binds to N-acetyl-glucosamine and N-acetyl-neuraminic acid residues, the pericellular matrix of rat tracheal cartilage appears to consist of proteoglycan having a high concentration of these saccharides.

Comparison between the effects of dexamethasone and indomethacin on bone wound healing

The area of wound holes made in the parietal bone of 4-week-old rats was measured at 1, 2 and 4 weeks after the operation using Alizarin red S staining without the use of histological sections. Dexamethasone and indomethacin were administered s.c. after the operation every day except Sunday. The inhibitory action of dexamethasone on bone wound healing was stronger than that of indomethacin, as was its inhibitory action on skin wound healing. Inhibition of the age-related decrease in radiolucency of femurs and some changes in serum calcium level were also observed by dexamethasone administration, but not by indomethacin. These results suggest that dexamethasone inhibits bone wound healing through its effects on calcium metabolism in addition to its general inhibitory action on wound healing which is shared with indomethacin. Dexamethasone also strongly inhibited the decrease in Alcian blue stainability which occurs with an increase in age, both in the normal portion and in the wound hole portion of the calvaria, whereas indomethacin showed a weak inhibitory effect only in the wound hole portion. This result suggests that one of the mechanisms by which dexamethasone inhibits bone wound healing may be based on the retardation of mineralization caused by the inhibition of removal of acid mucopolysaccharide.

The dentinogenic ghost cell tumor

An unusual case and they of dentinogenic ghost cell tumor, a peculiar variant of calcifying odontogenic cyst, is reported. The tumor consisted predominantly of ghost cells with occasional areas of "dentinoid" in close proximity to masses of ghost cells. The presence of ameloblastoma-like nests of epithelium was characteristic of the present case and they were interpreted as a degenerative phenomenon exhibiting an inductive effect with formation of abundant ghost cells, occurring within a pre-existing ameloblastoma. The term of "dentinogenic ghost cell tumor" is employed for this unique lesion presented in this report. The literature describing the neoplastic potential of the calcifying odontogenic cyst is briefly reviewed.

Immunoperoxidase investigation of Regan isoenzyme of alkaline phosphatase in maxillary sinus carcinomas

The Regan isoenzyme of alkaline phosphatase is known to be produced ectopically by various malignant tumors. To assess whether this isoenzyme is expressed in maxillary sinus carcinomas, immunostaining for Regan isoenzyme was carried out on 35 maxillary sinus carcinomas comprising 27 squamous cell carcinomas, 6 adenocarcinomas, and 2 adenoid cystic carcinomas. The enzyme was shown to be present in 11 of 27 cases of squamous cell carcinoma, 2 of 6 cases of adenocarcinoma, and 1 of 2 cases of adenoid cystic carcinoma. Regan isoenzyme was identified in the cytoplasm and/or cell membrane of squamous cell carcinoma cells, whereas it was demonstrated mainly on the luminal membrane and in the secretions of both adenocarcinoma and adenoid cystic carcinoma cells. These findings show that Regan isoenzyme does, indeed, occur in maxillary sinus carcinomas.

Effect of calcium deficiency on the content of nonreducible crosslinks in rat mandibular bone

The effect of calcium deficiency on the content of the nonreducible cross-linking amino acid, pyridinoline, in rat mandibular bone was studied. An apparent decrease in serum and bone calcium levels was observed beginning at four weeks after initiation of a calcium-deficient diet. The pyridinoline content in the bone of calcium-deficient animals began to increase at four weeks and thereafter increased markedly as compared to that of controls. Collagen content increased significantly six weeks after calcium deficiency. These results suggest that calcium deficiency inhibits mineralization and promotes the formation of pyridinoline in rat mandibular bone.

Reduced collagen biosynthesis in oral mucosa of beige (Chediak-Higashi) mice

Oral mucosa of beige (Chediak-Higashi) mice had decreased levels of collagen synthesis and prolyl hydroxylase activity compared with normal animals. No significant difference was observed in non-collagen protein synthesis between the two groups. These results suggest that decreased collagen biosynthesis in oral tissues may be partially involved in the increased incidence of periodontal disease in the Chediak-Higashi syndrome.

Localization of hepatitis B surface antigen in the human parotid gland

Localization of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the human parotid gland and liver was studied by an immunohistochemical method in four cases with seropositive HBsAg. Neither HBsAg nor HBcAg could be detected in the parenchymal cells of the parotid gland in any of the cases. However, one of four cases, which had the highest titer of serum HBsAg, showed HBsAg immunoreactivity in the vascular wall and luminal fluid of the parotid gland. In liver, HBsAg was detected in three and HBcAg in two of the four cases, respectively. HBsAg was localized in the cytoplasm of hepatocytes, while HBcAg was localized mainly in their nuclei. The detection of HBsAg in the parotid gland and liver was correlated with the serum titer of the antigen. The results indicate that the HB virus does not have an affinity for or a replicate in the parotid gland. Also, it is suggested that the HBsAg found in saliva is derived from HBsAg circulating through the oral mucosa by capillary leakage and not from secretion into the mouth by the salivary gland.

Age-related changes in the content of non-reducible crosslinks in rat mandibular bone

Age-related changes in the content of non-reducible crosslink amino acids, pyridinoline and histidinoalanine, in rat mandibular bone were studied. The pyridinoline content markedly increased up to 12 months of age and thereafter slightly increased. The histidinoalanine content was low until 3 months of age, but thereafter increased significantly up to 24 months. Total collagen content remained constant throughout the experiment. From these results, pyridinoline and histidinoalanine may serve as markers for the maturation and senescence, respectively, of mandibular bone.

Peroxidase activity in salivary glands and saliva of beige (Chediak-Higashi) mice

Peroxidase activity was lower in the submandibular and parotid glands of beige mice than in controls. A lower level of activity was also observed in the isoproterenol-elicited saliva of beige mice.

Selective inhibition of type I collagen synthesis in osteoblastic cells by epidermal growth factor

We have investigated the effect of epidermal growth factor (EGF) on collagen metabolism in clonal MC3T3-E1 cells, an osteoblastic cell line derived from newborn mouse calvaria. EGF significantly increased DNA synthesis, but decreased collagen production. We analyzed the amount of total collagen synthesis and degradation products of collagen together with the level of the enzyme responsible for extracellular collagen degradation, to investigate whether the decreased collagen production was due to a decrease in total collagen synthesis or to an increase in collagen degradation. Total collagen synthesis, determined by total hydroxyproline synthesized, was significantly decreased in cells cultured in medium containing EGF, but the amount of collagen degradation products and the level of animal collagenase activity were not increased. Analysis of the collagen type produced by the cells in the absence of EGF showed that 95% of the collagen recovered was type I and 3% was type III. The decreased level of collagen accumulated by cells cultured in the presence of EGF was explained only by the decreased rate of type I collagen synthesis. These results indicate that EGF selectively inhibits type I collagen synthesis in the clonal osteoblastic cell line, MC3T3-E1.

Effect of transferrin on alkaline phosphatase activity and collagen synthesis in osteoblastic cells derived from newborn mouse calvaria

The effect of transferrin was tested on osteoblastic cells (clone MC3T3-E1) cultured in serum-free medium containing 1% bovine serum albumin (BSA). Transferrin (Tf) stimulated increases of protein content and protein synthesis, but not of DNA content and cell number, in the cells. This protein also increased alkaline phosphatase activity and collagen synthesis in combination with 1% BSA. Actinomycin D and cycloheximide inhibited alkaline phosphatase activity induced by Tf, suggesting that Tf may enhance de novo synthesis of the enzyme. These results indicate that Tf may be involved in differentiation of osteoblastic cells, but not in their proliferation, in vitro.

Immunohistochemical localization of nerve growth factor and epidermal growth factor in guinea pig prostate gland

Prostate glands of adult guinea pigs were stained for nerve growth factor (NGF) and epidermal growth factor (EGF) by immunohistochemical methods. Both NGF and EGF were localized diffusely in the cytoplasm of the glandular epithelial cells, and also in their secretory products. These findings suggest that NGF and EGF are synthesized, stored, and secreted by the glandular epithelial cells of the prostate.

Prevalence of diabetes mellitus in a rural area of Japan: by 75 g OGTT

Tests for DM using the 75 g OGTT method (NDDG diagnostic criteria) were performed on 3145 persons living in rural areas of 8 different geographical regions of Japan (from Tohoku to Kyushu regions). Considerable regional difference was observed with western Japan tending to have higher DM and IGT rates than eastern Japan. The DM and IGT prevalence rates (for rural areas in Japan) were 3.9% and 6.9% respectively, and the DM detection rate was 2.8%. Comparison between normals and disturbance of glucose tolerance group (DM and IGT) on the basis of risk factors for atherosclerotic angiopathy showed that those with abnormal findings were definitely more numerous in the disturbance of glucose tolerance group.

The effect of streptozotocin-induced diabetes on prolyl hydroxylase activity in rat gingiva

The diabetes resulted in marked decrease in prolyl hydroxylase (EC 1.14.11.2) activity in rat gingiva. Insulin treatment of diabetic rats returned the decreased enzyme activity to the level of normal controls. The results suggest that diabetes decreases the rate of collagen biosynthesis in gingival tissue by inhibiting the hydroxylation of peptidyl proline in collagen precursors.