Enhancement of XPG mRNA expression by human interferon-beta in Cockayne syndrome cells

Using PCR-differential display, we have searched for genes expressed specially in human interferon (HuIFn)-beta-treated Cockayne syndrome (CS) fibroblast cells. Eighteen expressed genes induced by HuIFN-beta were identified, the sequences of seven of which were highly homologous to previously cloned sequences. The cDNAs of six of these seven clones were similar to expression tagged sequences from unknown genes in databases and the remaining one was identical to the cDNA of the xeroderma pigmentosum XPG gene. These results, together with our previous finding of increased resistance to ultraviolet (UV) cell-killing of CS cells pretreated with HuIFN-beta prior to UV irradiation suggest that XPG might be one of the genes possibly involved in the HuIFN-beta-induced UV-resistance.

Limitation of endorectal ultrasonography: what does a low lesion more than 5 mm in size correspond to histologically?

PURPOSE

The accuracy of diagnosis of metastatic lymph nodes for rectal carcinoma has not improved. A low echoic lesion more than 5 mm in size detected by endorectal ultrasonography is preoperatively assessed as a metastatic lymph node. What does a low echoic lesion more than 5 mm in size correspond to histologically?

METHODS

Forty-seven patients with lower rectal carcinoma (Term I, 1986-1990) and 48 patients with lower rectal carcinoma (Term II, 1991-1995) undergoing endorectal ultrasonography were reviewed. Surgically resected rectal specimens from 40 patients with rectal carcinoma underwent ultrasonography. Low echoic lesions more than 5 mm in size were taken from resected specimens and were stained with hematoxylin, followed by histologic examination.

RESULTS

The accuracy of diagnosis of metastatic lymph nodes of Term II was not higher than that of Term I. Twenty-five low echoic lesions were detected by ultrasonography using 40 resected specimens. Seventeen of these 25 lesions (68 percent) were histologically confirmed to be metastatic lymph nodes. One of 25 (4 percent) was found to be lymphadenitis with no metastasis. Among the 25 lesions, 5 (20 percent) were histologically confirmed to be tumor deposits, 2 (8 percent) fatty tissue, and 22 (88 percent) carcinoma.

CONCLUSIONS

Low echoic lesions were histologically confirmed to be tumor deposits (20 percent) and metastatic lymph nodes (68 percent). Although these data show deficiencies and limitations of the accuracy of endorectal ultrasonography, they compare favorably with other series, and no other current technology can show similar accuracy.

Establishment of ameloblastoma cell line, AM-1

Ameloblastomas are slowly growing, locally invasive neoplasms with a potentially destructive behaviour. The molecular mechanisms that regulate the cell growth and invasion of ameloblastoma cells are unknown. Because ameloblastoma cells placed in culture have a very limited lifespan, the establishment of immortalized clones of ameloblastoma cells would aid its study. We produced an immortalized ameloblastoma cell line (AM-1) using human papillomavirus type-16. This cell line maintains epithelial cell morphology and expresses cytokeratins K8, K14, K18, K19. Furthermore, bcl-2 protein, which prevents apoptosis, is expressed. We investigated the behaviour of these cells on a collagen matrix in vitro. These cells grew in a monolayer over foci of collagen degradation and could invade the collagen gel at such sites. Since the behavior of cell line AM-1 mimics the behavior of ameloblastoma in vivo, it may be a valuable model for the study of these neoplasms.

Small spot sign of rectal carcinoma by endorectal ultrasonography: histologic relation and clinical impact on postoperative recurrence

PURPOSE

We observed small spots at the margin of rectal carcinomas on endorectal ultrasonography. Our aim was to study the relationship between ultrasonographic evidence of these spots and histologic characteristics of disease and postoperative recurrence.

PATIENTS AND METHODS

The study group comprised 55 patients, 36 men and 19 women, with rectal carcinoma as confirmed by biopsy. The patients were followed up at three-month intervals for six months to three years and six months after the operation. Endorectal ultrasonography was performed in the usual manner. Surgically resected specimens were stained with hematoxylin and eosin and histologically examined. Vessel invasion was graded from 0 (not invasive) to 3 (most invasive).

RESULTS

Among the 55 patients studied, 3 had Stage T2,N0,M0 rectal carcinomas and 35 had Stage T3,N0,M0 carcinomas, 5 (14.3 percent) of whom had echographic evidence of small spots. Thirteen patients had Stage T3,N1/2,M0 carcinomas, comprising 12 (92.3 percent) with small spots, and four patients had T3,N1/2,M1 carcinomas, all with small spots. Vessel invasion of Grade 2 or higher was observed around the carcinomas in 20 of 21 patients who had small spots. Ten of 13 patients with many spots at the margin of the carcinoma (a spot grade of ++) histologically had marked venous or lymphatic invasion (an invasion Grade 3). The presence of small spots was closely associated with massive venous or lymphatic invasion (a vessel invasion grade of 2 or more). Four patients had synchronous liver metastases, and small spots were found in all four. Distant metastases and local recurrence were found in 11 of 21 patients with small spots. We found no recurrence in any patient without small spots on endorectal ultrasonography.

CONCLUSIONS

Small spots indicate the presence of massive venous or lymphatic invasion and a high risk of postoperative recurrence.

Steroid complications and surgery in intractable ulcerative colitis

The major operative indication for ulcerative colitis is intractability. Although steroid side effects appear to be closely associated with surgical indications for intractable ulcerative colitis, this relationship has yet to be analyzed in detail. To elucidate this relationship, we investigated 39 surgical patients with intractable ulcerative colitis, as defined by the Research Committee for Intractable Diseases of the Ministry of Health and welfare of Japan, and 66 conservatively treated patients with ulcerative colitis, of whom 6 had intractable disease. All patients with major steroid side effects and 17/24 (71%) patients with minor side effects underwent surgery. The median number of admissions was higher in patients with major side effects than in those with less severe or no side effects in the operative series, while this value was lower in the non-operative series than in the operative series. This tendency was similar for the total duration of hospitalization and the number of relapses. In the operative series, markedly higher steroid doses were administered to patients with side effects than to those without, and lower doses were given in the non-operative series. On multivariate regression analysis, the presence of steroid side effects, disease extent, and disease duration were significantly associated with surgery. Patients without side effects had a higher postoperative complication rate than those with minor side effects. We conclude that major side effects are a surgical indication for patients with intractable ulcerative colitis, and that even minor side effects should be taken as a surgical indication in view of the patient's quality of life.

Functional magnetic resonance imaging during recognition of written words: Chinese characters for concrete objects versus abstract concepts

An attempt was made to apply functional magnetic resonance imaging (fMRI) to reveal cortical areas activated upon presentation of two groups of Chinese characters in six normal right-handed, male, Japanese subjects. Presentation of the characters representing 'abstract concepts' activated the bilateral occipital region without a significant difference between the bilateral occipital and temporal regions. Presentation of the characters representing 'concrete objects' resulted in significantly stronger activation in the left occipital and temporal regions. These results suggest that recognition of concrete characters involves a stronger initial process in the left occipital temporal cortices than recognition of abstract characters.

Living-related liver transplantation and neurological outcome in children with fulminant hepatic failure

BACKGROUND

Fulminant hepatic failure (FHF) in children is associated with high mortality under medical management. Living-related liver transplantation (LRLT) is an accepted measure to treat the children with end-stage liver disease. Reversibility of hepatic encephalopathy is crucial for the quality of life among the survivors after transplantation.

METHODS

A retrospective review was made of the records of children undergoing LRLT at this hospital between May 1992 and November 1996.

RESULTS

Eleven children with FHF underwent emergency LRLT. The mean age was 5 years (range, 2 months to 15 years). The indication for transplantation was persistent or worsening hepatic encephalopathy and severe coagulopathy, despite repeated plasma exchanges or exchange transfusions. The cause of FHF was non-A, non-B hepatitis in seven children, hepatitis B in two children, herpes simplex virus hepatitis in one child, and fulminant Wilson's disease with intravascular hemolysis in one child. The grade of hepatic encephalopathy was II in four children, III in two, and IV in five. The actuarial survival rate was 73% after a mean follow-up of 28 months (range, 13-67 months). Short-term neurological morbidity was present in two children with grade IV encephalopathy who also showed brain edema on cranial computed tomography. Eight survivors exhibited no long-term neurological deficit; the mean intelligence or developmental quotient was 97 (range, 86-110) at the end of the follow-up period.

CONCLUSIONS

LRLT is an effective option for the treatment of FHF in children. The long-term neurological status is satisfactory among survivors.

Phenotypic differences between T-->C and T-->G mutations at nt 8993 of mitochondrial DNA in Leigh syndrome

This study reports on a patient with Leigh syndrome with a T-to-C mutation at nucleotide 8993 of mitochondrial deoxyribonucleic acid (T8993C). The authors reviewed 10 Leigh syndrome patients, including ours, with T8993C. Compared with 18 reported patients with Leigh syndrome caused by a T-to-G mutation at nucleotide 8993 (T8993G), Leigh syndrome with T8993C was characterized by a significantly higher frequency of ataxia (P < 0.01). None of the reviewed T8993C-associated Leigh syndrome patients had retinitis pigmentosa, which is one of the characteristic findings in Leigh syndrome with T8993G. The milder symptoms of T8993C-Leigh syndrome can be explained by the milder complex V dysfunction; however, the higher frequency of ataxia in T8993C-Leigh syndrome requires more study.

Active oxygen-mediated chromosomal 1-2 Mbp giant DNA fragmentation into internucleosomal DNA fragmentation in apoptosis of glioma cells induced by glutamate

C6 glioma cells treated with 10 mM glutamate reduced intracellular GSH to one-seventh of the initial level, and induced cytolysis accompanied by apoptosis. The treated cells produced extracellular H2O2. The cytolysis of the C6 cells induced by glutamate was prevented by antioxidants such as N-acetylcysteine (NAC), ascorbic acid (ASC), catalase, and NaN3, iron chelators such as deferoxamine and 1,10-phenanthroline, and oxygen radical scavengers such as 5,5'-dimethyl-1-pyrroline-N-oxide (DMPO) and alpha-phenyl-tert-butyl nitrone (PBN). The effect of these antioxidants, iron chelators, and oxygen radical scavengers on the cytolysis of C6 cells was dependent on the dose and the intracellular GSH level. Furthermore, 1-2 Mbp chromosomal DNA (giant DNA) fragments were observed during cytolysis. The giant DNA fragments were further cleaved into smaller DNA fragments of 200-800 kbp, and then to fragments of less than 300 kbp in size including chromosomal ladder DNA fragments. Such serial chromosomal DNA degradations induced by glutamate were also inhibited by addition of these antioxidants, iron chelators, and oxygen radical scavengers. These findings suggest that glutamate induces GSH depletion, and consequently, apoptosis through endogenously produced active oxygen species in C6 glioma cells and that the apoptosis is accompanied by 1-2 Mbp giant DNA fragmentation prior to the internucleosomal DNA fragmentation.

Bone morphogenetic protein signaling is required for maintenance of differentiated phenotype, control of proliferation, and hypertrophy in chondrocytes

To examine the role of bone morphogenetic protein (BMP) signaling in chondrocytes during endochondral ossification, the dominant negative (DN) forms of BMP receptors were introduced into immature and mature chondrocytes isolated from lower and upper portions of chick embryo sternum, respectively. We found that control sternal chondrocyte populations expressed type IA, IB, and II BMP receptors as well as BMP-4 and -7. Expression of a DN-type II BMP receptor (termed DN-BMPR-II) in immature lower sternal (LS) chondrocytes led to a loss of differentiated functions; compared with control cells, the DN-BMPR- II-expressing LS chondrocytes proliferated more rapidly, acquired a fibroblastic morphology, showed little expression of type II collagen and aggrecan genes, and upregulated type I collagen gene expression. Expression of DN-BMPR-II in mature hypertrophic upper sternal (US) chondrocytes caused similar effects. In addition, the DN-BMPR-II-expressing US cells exhibited little alkaline phosphatase activity and type X collagen gene expression, while the control US cells produced both alkaline phosphatase and type X collagen. Both DN-BMPR-II-expressing US and LS chondrocytes failed to respond to treatment with BMP-2 . When we examined the effects of DN forms of types IA and IB BMP receptors, we found that DN-BMPR-IA had little effect, while DN-BMPR-IB had similar but weaker effects compared with those of DN-BMPR-II. We conclude that BMP signaling, particularly that mediated by the type II BMP receptor, is required for maintenance of the differentiated phenotype, control of cell proliferation, and expression of hypertrophic phenotype.

Increase in nitric oxide in the hypoxic-ischemic neonatal rat brain and suppression by 7-nitroindazole and aminoguanidine

We measured the changes in nitric oxide (NO) metabolites in the brains of neonatal rats with hypoxic-ischemic damage. There were two peaks of NO metabolites in the lesioned side of the cortex without treatment: one during hypoxia and the other during the re-oxygenation period. Prehypoxic treatment with 7-nitroindazole, a selective neuronal NO synthase inhibitor, suppressed both peaks of NO metabolites, whereas prehypoxic treatment with aminoguanidine, a selective inducible NO synthase inhibitor, partially suppressed only the peak in the re-oxygenation period. These data suggest different roles of neuronal and inducible NO synthases in the pathogenesis of hypoxic-ischemic encephalopathy.

Computed tomographic features of calcifying odontogenic cysts

OBJECTIVES

To describe the CT appearances of 4 cases of the calcifying odontogenic cyst (COC) with particular reference to the effect of varying the window settings.

METHODS

Conventional radiographs and CT scans of 4 calcifying odontogenic cysts were analyzed with respect to the presence of an impacted tooth, root resorption and calcification. In addition, increased attenuation by desquamated keratin was examined by varying the window settings on CT.

RESULTS

All lesions were located in the maxilla and on conventional radiographs, had unilocular radiolucency with a well-defined margin. Calcifications and inclusion of an impacted tooth were seen in all cases. Root resorption was observed in two cases, but was not prominent. On CT, calcification was detected at the periphery of the lesion and/or around the impacted tooth in all cases. Varying the window setting revealed an increased attenuation area due to desquamated keratin.

CONCLUSIONS

Varying the window setting on CT is useful as a means of identifying both desquamated keratin and peripheral calcification in COC.

Functional magnetic resonance imaging during recognition of written words: Chinese characters for concrete objects versus abstract concepts

An attempt was made to apply functional magnetic resonance imaging (fMRI) to reveal cortical areas activated upon presentation of two groups of Chinese characters in six normal right-handed, male, Japanese subjects. Presentation of the characters representing 'abstract concepts' activated the bilateral occipital region without a significant difference between the bilateral occipital and temporal regions. Presentation of the characters representing 'concrete objects' resulted in significantly stronger activation in the left occipital and temporal regions. These results suggest that recognition of concrete characters involves a stronger initial process in the left occipital temporal cortices than recognition of abstract characters.

Role of p53 and p21/WAF1 detection in patient selection for preoperative radiotherapy in rectal cancer patients

BACKGROUND

Recent studies showed that p53 and p21 may play major roles in determining tumor radiosensitivity through the apoptosis pathway. The aim of this study was to investigate the predicting value of radiosensitivity in human rectal carcinoma.

METHODS

p53 and p21/WAF1 expressions in formalin fixed, paraffin-embedded, preradiation biopsy samples from 49 patients with primary rectal carcinoma were analyzed immunohistochemically. p53 and p21 expressions and their relationships with histopathologic changes after radiation and other clinical features were evaluated.

RESULTS

Expressions of p53 and p21/WAF1 were 49 and 28.6 percent, respectively. In 36.7 percent of total tumors, significant histopathologic effect can be observed. There was a significant inverse expression of p53 and p21. Most of the p53(+) or p21(-) tumors were radioresistant, and the majority of p53(-) or p21(+) tumors were radiosensitive. Tumors size in the radiosensitive, p53(-), or p21(+) group decreased more significantly than in radioresistant, p53(+), or p21(-) group (P < 0.01), and patients with radioresistant, p53(+), or p21(-) tumors had more local recurrence, more distant metastasis, and a shorter five-year survival rate than those with radiosensitive, p53(-), or p21(+) tumors, but without statistic significance. No statistically significant correlation can be observed between other tumor clinical features and radiosensitivity, p53, or p21 expressions.

CONCLUSION

Immunohistochemistry detection of p53 and p21 expressions may be useful parameters for more radiosensitive patients selected for preoperative radiotherapy.

Unusual ligand structure in Ni-Fe active center and an additional Mg site in hydrogenase revealed by high resolution X-ray structure analysis

BACKGROUND

The hydrogenase of Desulfovibrio sp. catalyzes the reversible oxidoreduction of molecular hydrogen, in conjunction with a specific electron acceptor, cytochrome c3. The Ni-Fe active center of Desulfovibrio hydrogenase has an unusual ligand structure with non-protein ligands. An atomic model at high resolution is required to make concrete assignment of the ligands which coordinate the Ni-Fe center. These in turn will provide insight into the mechanism of electron transfer, during the reaction catalysed by hydrogenase.

RESULTS

The X-ray structure of the hydrogenase from Desulfovibrio vulgaris Miyazaki has been solved at 1.8 A resolution and refined to a crystallographic R factor of 0.229. The overall folding pattern and the spatial arrangement of the metal centers are very similar to those found in Desulfovibrio gigas hydrogenase. This high resolution crystal structure enabled us to assign the non-protein ligands to the Fe atom in the Ni-Fe site and revealed the presence of a Mg center, located approximately 13 A from the Ni-Fe active center.

CONCLUSIONS

From the nature of the electron-density map, stereochemical geometry and atomic parameters of the refined structure, the most probable candidates for the four ligands, coordinating the Ni-Fe center, have been proposed to be diatomic S=O, C triple bond O and C triple bond N molecules and one sulfur atom. The assignment was supported by pyrolysis mass spectrometry measurements. These ligands may have a role as an electron sink during the electron transfer reaction between the hydrogenase and its biological counterparts, and they could stabilize the redox state of Fe(II), which may not change during the catalytic cycle and is independent of the redox transition of the Ni. The hydrogen-bonding system between the Ni-Fe and the Mg centers suggests the possible.

Cyst-like lesion of a developing tooth induced by mandibular fracture

A dentigerous cyst-like formation in the lower canine region caused by mandibular fracture in a 10-year-old boy is reported. His medical history revealed that he had been unconscious for about 2 weeks after traumatic head injuries sustained in a traffic accident, and a complicated mandibular fracture had been left untreated until his dentist diagnosed the lesion. Eleven months after trauma, a dentigerous cyst measuring 20 mm in diameter was found in the fracture area. The lesion was enucleated and the boy's postoperative recovery was uneventful. The mass completely enveloped the developing canine, and epithelial cells proliferated into the connective tissue. However, there was no distinct epithelial lining. Small round cell infiltrations and several vessels with thrombosis were noted in the cyst wall. The cause of cyst formation was considered to be infection of the canine tooth bud and the surrounding soft tissue.

Structure of Cytochromec' fromRhodobacter capsulatusStrain St Louis: An Unusual Molecular Association Induced by Bridging Zn Ions

Rhodobacter capsulatus strain St Louis cytochrome c' (RCCP-SL) has been crystallized and the structure solved by molecular replacement. It was refined at 2.1 A resolution to an R value of 18.4%, and compared with Rhodobacter capsulatus strain M110 cytochrome c' (RCCP-M110). Although these two proteins are very similar in sequence and structure, the intermolecular interaction is largely different. In RCCP-M110, the molecules dimerize through interaction of helix B to form an antiparallel arrangement. When crystallized in the presence of Zn ions, molecules of RCCP-SL were found to be arranged as linear polymers connected by the bridging Zn ions. The changes in conformation of the side chains induced by binding of the Zn ions, by the substitution of Glu90 for Asp90, and by the different arrangement of the molecules, are discussed in detail.

Crystal structure of DNA photolyase from Anacystis nidulans

The crystal structure at 1.8 A resolution of 8-HDF type photolyase from A. nidulans shows a backbone structure similar to that of MTHF type E. coli photolyase but reveals a completely different binding site for the light-harvesting cofactor.

Ultrasonographic texture characterization of salivary and neck masses using two-dimensional gray-scale clustering

OBJECTIVES

To evaluate the clinical usefulness of texture analysis in ultrasonography (US) of head and neck masses.

METHODS

Sixty-one cases with salivary or neck masses were examined by US with a linear 7.5MHz array. Images were digitized and quantitatively evaluated by two-dimensional gray-scale clustering using two texture indices, M and SD, as measures of coarseness and homogeneity respectively.

RESULTS

Coarseness of Warthin's tumors was significantly higher than that of the other salivary tumors. Malignant lymphomas had finer texture values than other lymph node lesions.

CONCLUSIONS

Quantitative texture analysis appears to be a useful complement in diagnostic US.

Synthetic studies of vitamin D analogs. XXIV. Synthesis of active vitamin D3 analogs substituted at the 2 beta-position and their preventive effects on bone mineral loss in ovariectomized rats

Analogs related to 1 alpha,25-dihydroxy-2 beta-(3-hydroxypropoxy)vitamin D3 (ED-71) (4), oxa-type and carba-type analogs of vitamin D3 bearing substituents at the 2 beta-position of 1 alpha,25-dihydroxyvitamin D3 (1), were synthesized from the alpha-epoxides (6 and 13). Three analogs, ED-71 (4) and two carba-type analogs (16 and 26), showed potent preventive effects on bone mineral loss in pre-osteoporosis model rats. ED-71 (4) was concluded to be an optimized analog and a promising candidate for the treatment of osteoporosis.

Immunohistochemical demonstration of bcl-2 protein in ameloblastoma

The bcl-2 gene is known through its product, bcl-2 protein, which prevents apoptosis, and also by its expression in development, especially in sites characterized by epithelial-mesenchymal interactions. In the developing tooth germ, bcl-2-protein is expressed in the epithelial component. In this study, we examined the expression of bcl-2 protein immunohistochemically in 25 ameloblastomas using a monoclonal antibody against anti-human bcl-2 oncoprotein. In all 25 cases, bcl-2 protein was found mainly in the outer layer of tumor cells, whereas the inner cells (stellate reticulum-like cells and squamoid cells) were negative. The bcl-2 protein is therefore thought to play a role in maintaining the stem-cell population in the peripheral layers of the tumor nests from which proliferating cells can be recruited.

Induction of osteogenic differentiation by hedgehog proteins

In this study we asked whether members of the hedgehog gene family are involved in osteogenesis. C3H10T1/2 cells and MC3T3-E1 cells expressed the putative hedgehog receptor patched (Ptc) gene. Medium conditioned by chicken embryo fibroblast cultures expressing either Indian hedgehog or Sonic hedgehog stimulated alkaline phosphatase (APase) activity in cultures of the mouse mesenchymal cell line C3H10T1/2 and the osteoblastic cell line MC3T3-E1. These stimulatory effects were synergistically enhanced by bone morphogenetic protein-2 (BMP-2). Treatment with the amino-terminal portion of recombinant Sonic hedgehog proteins (rShh-N) up-regulated the expression of the Ptc gene within 12 h and increased production of APase in C3H10T1/2. rShh-N and BMP-2 also synergistically stimulated APase activity. rShh-N treatment did not affect the expression levels of Bmp-2, -4, -5, -6 and -7 genes. These findings indicate that hedgehog proteins directly act on osteogenic precursor cells and osteoblasts and stimulate osteogenic differentiation of these cells in co-operation with BMPs.

Structure of the murine CD156 gene, characterization of its promoter, and chromosomal location

The murine cell surface antigen mCD156 is a glycoprotein that is expressed in monocytic cell lines and consists of a metalloprotease domain, a disintegrin domain, a cysteine-rich domain, and an epidermal growth factor-like domain in the extracellular region. The mCD156 gene is composed of 24 exons and 23 introns and spans approximately 14 kilobases. The first exon encodes most of the signal peptide sequence, and the transmembrane region is encoded by a single exon (19). In contrast, the other regions are composed of multiple exons. Of these, exons 7-12 and 12-15 encode a metalloprotease domain and a disintegrin domain, respectively. Sequence analysis of the 5'-flanking DNA revealed many potential regulatory motifs. Chloramphenicol acetyltransferase analysis demonstrated that nucleotides at positions -183, -334, and -623 contained cis-acting enhancing elements in a mouse monocytic cell line, aHINS-B3. Nucleotides at positions -183 and -390 contained elements responsible for lipopolysaccharide (LPS) inducibility, although several other 5'-flanking regions were also involved in LPS responsiveness. Regions -202, -507, and -659 play a role in interferon-gamma inducibility. Some of the potential regulatory motifs and other unknown cis elements may be involved in the constitutive expression, and LPS and interferon-gamma inducibilities. The mCD156 gene was mapped to chromosome 7, region F3-F4.

Morphologic analysis of odontogenic cysts with computed tomography

PURPOSE

The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology.

MATERIAL AND METHODS

Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst.

RESULTS

As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis.

CONCLUSION

Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group.

Primary structure of rat CD14 and characteristics of rat CD14, cytokine, and NO synthase mRNA expression in mononuclear phagocyte system cells in response to LPS

Rat CD14 cDNA clones were isolated. The predicted protein sequence exhibits 82, 61.6, and 64% identity with the mouse, rabbit, and human CD14, respectively. The levels of rat CD14 mRNA expression in resident peritoneal macrophages (PM), alveolar macrophages (AM), and peripheral blood monocytes (BM) were constitutively high, whereas that in Kupffer cells (KC) was low. On intravenous injection with lipopolysaccharide (LPS), the expression of rat CD14 mRNA in KC increased markedly, whereas the increases in PM, AM, and BM were mild. Similar features of expression of rat CD14 in these cells were observed after stimulation with LPS in vitro. The level of tumor necrosis factor alpha (TNF-alpha) mRNA expression in KC after stimulation with LPS in vivo was comparable to that in PM, AM, and BM, whereas that of TNF-alpha mRNA expression in KC and PM after stimulation with LPS in vitro was lower than that in AM and BM. Interleukin (IL)-1 beta and iNOS mRNA expressions in KC after stimulation with LPS in vivo and in vitro were low, whereas those in PM, AM, and BM were high. Little or no expression of IL-6 was observed in KC after stimulation with LPS in vivo and in vitro, whereas higher expression was observed in PM, AM, and BM than in KC.

Lack of promotion of colon carcinogenesis by high-oleic safflower oil

BACKGROUND

The nonpromoting effect of olive oil on colon carcinogenesis has been attributed to its high oleic acid content, whereas a positive association of monounsaturated fat in beef tallow with colon tumors has been reported. The effect of constituents other than fatty acids could not be neglected in these experiments. In order to minimize the effects of minor constituents in the oils, the authors compared conventional safflower oil with oil from a mutant strain of safflower that is rich in oleic acid.

METHODS

ICR mice were treated with 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight every week for 12 weeks) and then were fed either a high-fat diet (23.5% by weight), containing safflower oil (HF-LA) or high-oleic safflower oil (HF-OA), or a low-fat diet (5% by weight), containing safflower oil (LF-LA) or high-oleic safflower oil (LF-OA). The test diets were continued until termination of the experiment at 30 weeks after the first administration of DMH. Fatty acid composition of colon phospholipids was determined by gas-liquid chromatography-mass spectrometry.

RESULTS

Tumor multiplicity in animals fed the HF-OA diet was indistinguishable from that in animals fed LF-LA or LF-OA. In contrast, animals fed the HF-LA diet had a significantly higher incidence of colon tumors (mostly adenocarcinomas) than the other groups. Fatty acid profiles of colon phospholipids reflected those of the diet. Animals fed a HF-LA diet showed a marked decrease of nervonic acid (C24:1, n-9) in the colon sphingomyelin.

CONCLUSIONS

These data indicate that oleic acid does not enhance DMH-induced colon carcinogenesis in mice, even when they are fed a high-fat diet.

CD156 (human ADAM8): expression, primary amino acid sequence, and gene location

The murine cell-surface antigen MS2 [ADAM 8; mouse CD156 (mCD156)] is a transmembrane glycoprotein that is highly expressed in monocytic lineages. mCD156 consists of a long exterior region containing domains strikingly similar to those of hemorrhagic snake venom proteins. cDNA for human CD156 was isolated from cDNA libraries from the human macrophage cell line THP-1 and from human granulocytes. The CD156 cDNA detected mRNA from human macrophage cell lines, granulocytes, monocytes, and B cell but not T cell lines. The nucleotide sequence of the CD156 cDNA showed 65.6% homology with that of mCD156, and its amino acid sequence had high homology with hemorrhagic snake venom proteins and other related mammalian proteins. The CD156 gene was mapped to human chromosome 10q26.3.

Early-childhood progressive myoclonus epilepsy presenting as partial seizures in dentatorubral-pallidoluysian atrophy

PURPOSE

We explored the characteristics of epileptic seizures of progressive myoclonus epilepsy (PME) in 2 brothers with dentatorubral-pallidoluysian atrophy (DRPLA).

METHODS

We obtained the case history of the siblings and ictal and interictal EEGs. Postmortem examination or demonstration of elongated CAG repeat in the gene for DRPLA was used to confirm the diagnosis.

RESULTS

Two Japanese siblings developed PME characterized by versive or himiclonic seizures with or without secondarily generalized tonic-clonic convulsions. The elder brother regressed mentally and exhibited increasing spasticity after age 1 year. Myoclonus and seizures developed at age 4 years. The younger brother had shown psychomotor retardation before age 4 years, when he began to deteriorate further neurologically as the elder brother had. He also developed myoclonus and seizures at that age. Seizures in both patients remained partial until their deaths at ages 19 and 15 years, respectively. Ictal EEG verified partial onset of seizure evolving to generalized tonic-clonic seizure (GTCS). Interictal EEGs showed multifocal paroxysmal discharges with little or no diffuse paroxysms. Postmortem examination or genetic study confirmed the diagnosis of DRPLA.

CONCLUSIONS

Seizures of patients with DRPLA may present as partial seizures in children with early-onset PME.

Reliability of ultrasonography and sialography in the diagnosis of Sjögren's syndrome

OBJECTIVE

The purpose of this study was to evaluate quantitatively observer performance with ultrasonography and sialography in the diagnosis of parotid gland involvement of Sjögren's syndrome.

STUDY DESIGN

Sixty-four parotid gland sialograms and 65 ultrasonograms were prepared for observer performance experiments. They included both modalities in 24 Sjögren's syndrome and 19 nonspecific parotitis cases, 21 normal parotid gland sialograms, and 22 normal ultrasonograms in healthy volunteers. The images were randomly sequenced and presented to five observers who were asked to describe several findings and finally to determine the imaging diagnosis by ranking the abnormal features and the diagnosis on a five-point-rating scale. Observer performance was evaluated on the basis of the reliability of findings interpreted and the diagnostic accuracy of each modality from observers' rating scores.

RESULTS

The diagnostic accuracy of sialography was very high, nearly perfect. The diagnostic accuracy of ultrasonography was lower than that of sialography, resulting from the lower incidence of characteristic findings in the disease groups and lower sensitivity on ultrasonography. In the differentiation of Sjögren's syndrome from the normal, however, the diagnostic accuracy of ultrasonography increased to 80% for all cases, and up to nearly 90% in the advanced sialographic stages.

CONCLUSION

Ultrasonography is useful for the diagnosis of Sjögren's syndrome in the advanced stages. Taking the noninvasiveness of this technique into account we recommend first applying ultrasonography to the diagnosis of Sjögren's syndrome and performing sialography when no positive findings are detected on ultrasonography.

[18F]-fluorodeoxyglucose-positron emission tomography findings in protein infants with severe periventricular leukomalacia and hypsarrhythmia

Two preterm infants with extensive periventricular leukomalacia (PVL) were examined by [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) at the corrected ages of 18 and 34 days. They showed similar clinical courses including oculoclonic seizure, hypsarrhythmia and severe mental retardation, in addition, to spastic quadriplegia. FDG-PET study of these two infants with severe PVL disclosed poorly developed metabolic activity in the primary sensorimotor cortex, while the MRI images displayed only periventricular white matter lesions.

CONCLUSIONS

Positron emission tomography may disclose cortical involvement in infants with severe periventricular leukomalacia.

Brain atrophy in congenital neuromuscular disease with uniform type 1 fibers

We report a patient with congenital neuromuscular disease with uniform type 1 fibers. The patient had manifested muscle weakness and running difficulty since early childhood. Ptosis and ophthalmoplegia were evident, in addition to facial and distal weakness. Her serum creatine kinase level was normal, and electromyography revealed low-amplitude and short duration of motor unit potentials. A muscle biopsy specimen demonstrated absolute predominance of type 1 fibers (> 98%) with no diagnostic structures. Her intelligence was borderline (IQ 80), and dilatation of the lateral ventricles was demonstrated by cranial CT. This is the first report of an abnormality in the central nervous system in congenital neuromuscular disease with uniform type 1 fibers.

Appearance of 1-2 Mbp giant DNA fragments as an early common response leading to cell death induced by various substances that cause oxidative stress

The effects of oxidative stress on double strand DNA breakage were examined in T-24 human bladder tumor cells using various active oxygen producing agents such as hydrogen peroxide (H2O2), bleomycin (BLM), neocarzinostatin (NCS), and x-ray irradiation. Analysis of the DNA by pulsed-field gel electrophoresis (PFGE) revealed that discrete giant DNA fragments of 1-2 Mbp and 200-800 kbp had accumulated in the nuclei of the treated cells. The 1-2 Mbp giant DNA fragments were first observed 2 h after the T-24 cells were exposed to the active oxygen producing agents, or irradiated with x-ray. The appearance and the amounts of 1-2 Mbp and 200-800 kbp giant DNA fragments seemed to depend on the concentration and the type of reagents used or the dose of x-ray. Following the accumulation of giant DNA fragments, another type of DNA fragmentation was detected and DNA fragments smaller than 100 kbp accumulated in the nuclei of the cells irradiated with x-ray or treated with NCS. In addition, DNA ladder formation, which is characteristic of apoptosis, was observed. The giant DNA fragments appeared to arise as a consequence of double-stranded DNA breakage, which occurred earlier than cell lysis, as assessed by 51Cr release. These findings indicate that the formation of giant DNA fragments is a specific characteristic of cells responding to oxidative stress, and it may be an initial event that leads to cell death.

Antitumor effect of Streptococcus pyogenes by inducing hydrogen peroxide production

The Su strain of Streptococcus pyogenes (S-coccus)-derived anticancer preparation, OK-432, which is immobilized by heating in the presence of penicillin G, is well known to have an immunopotentiating activity through activation of natural killer cells in vivo. In this study, a streptococcal anticancer preparation stronger than OK-432 was prepared. Live streptococci (S-cocci) of the Su strain were induced to acquire H202-producing ability by treatment with serum under aerobic conditions. The resulting preparation no longer possessed hemolytic activity, and was not viable. The serum-treated S-coccus preparation activated natural killer cells as well as OK-432 did, and had stronger antitumor activity than OK-432 did. These results suggest that the serum-treated S-coccus preparation would be a useful tool for chemotherapy, in addition to immunotherapy, for the treatment of cancer.

[An examination of two reporting methods of falls among the elderly living in the community]

This study examined the concordance of two reporting methods for falls (3 month and 12 month recall) experienced by elderly living in a rural community. Four interview surveys on the occurrence of falls over a 3 month period were conducted from 1992 to 1993 every three months. In the final interview, subjects were also asked about the occurrence of falls during the past 12 months. A total of 799 subjects (270 men, 529 women) aged 65 and over, living in a village of Niigata Prefecture, responded to all four surveys. The incidence of falls in one year was 19.0% by the 3 month recall, and 19.1% by the 12 month recall. Overall agreement of fall occurrence between the two methods was 98.9%, and a coefficient of kappa as a measure of concordance was 0.96. On the other hand, subjects who sustained injuries during falls reported in the 3 month reporting did not necessarily recall having a fall when interviewed at the end of the study. In any case, this study reveals that for surveying falls by the elderly living in the community a 1 year recall is a reliable method, because of the high agreement of fall occurrence when comparing the two methods.

Histologic investigation of hollow implants retrieved for psychological reasons

OBJECTIVE

The purpose of this study was to radiologically, histologically, and histometrically evaluate bone in the hollow portion of three implants retrieved for psychological reasons.

STUDY DESIGN

Three hollow implants retrieved from two patients were studied. We investigated the radiologic and histologic changes of these implants with the use of radiographs, light microscopy, image processing, and fluorescent microscopy.

RESULTS

There were no radiologic and histologic degeneration around the implants. Histometric analysis of the hollow indicated that the average percentage of bone contact rate was 33.5% in case 1, 74.5% in case 2, and 18.4% in case 3; the average percentage of bone filling was 25.1%, 33.9%, and 6.6%, respectively. There was a great variation among the three cases in bone to implant contact and bone filling.

CONCLUSION

The hollow portion in case 1 that penetrated into the maxillary sinus was encapsulated with fibrous tissue. The amount of bone tissue in the hollow portion seems to depend on the initial bone quality of the recipient sites.

Increased neurons containing neuronal nitric oxide synthase in the brain of a hypoxic-ischemic neonatal rat model

We evaluated the temporal profile of the number of neurons containing neuronal nitric oxide synthase (nNOS neurons) in the brain of a neonatal hypoxic-ischemic rat model. Hypoxic-ischemic insults were produced in the brains of 7-day-old rat pups using a combination of unilateral carotid artery ligation and hypoxic (8% oxygen) exposure. Sections of brain from rats killed at 0-24 h after the onset of hypoxia were stained immunohistochemically using a polyclonal anti-nNOS antibody. Histological changes of neuronal injury were evaluated in the adjacent Nissl stained sections. The number of nNOS neurons in the hemisphere ipsilateral to the carotid ligation was significantly increased (P < 0.05) at 3 h, when the neuronal injury consisted of clusters of degenerating hyperchromic neurons. Neuronal degeneration and an increased number of nNOS neurons were seen only in the ipsilateral hemisphere and the increase was most prominent in the dorsolateral area of the striatum. The increase in the number of nNOS neurons continued at 6 h, when the area of neuronal injury continued to expand. At 24 h, the neuronal injury was diffuse, and the number of nNOS neurons on the ipsilateral side significantly decreased. The increase of the number of nNOS neurons in the early phase of neonatal neuronal injury suggests its possible involvement in the hypoxic-ischemic injury. The delineation of its role in neuronal injury may lead to an improvement in managing neonatal hypoxic-ischemic brain injury.

Age changes in the rat temporomandibular joint articular disc: a biochemical study on glycosaminoglycan content

The temporomandibular joint (TMJ) articular discs were removed from female Sprague-Dawley rats 3, 5, 10, 32, 90 and 130 weeks of age. Glycosaminoglycans (GAGs) were extracted from the discs by heat treatment, alkali treatment and digestion with Pronase E, and purified by precipitation with cetylpyridinium chloride and ethanol. The concentration of total GAG was highest in the 3 week extracts and tended to decrease with age. Dermatan sulphate was the predominant GAG detected in all age groups along with chondroitin sulphate, hyaluronic acid and heparan sulphate. The disaccharides obtained from chondroitin sulphate were delta Di-4S, delta Di-6S and delta Di-0S, with delta Di-4S being the predominant isomer followed by delta Di-6S for all ages of all the GAG examined. The concentration of chondroitin sulphate showed a decrease with age. Quantitative changes of GAG with age may be related to functional changes in TMJ discs.

[Shichimotsu-koka-to prevents stroke and changes free-radical-related enzymes in stroke-prone spontaneously hypertensive rats (SHRSP)]

Shichimotsu-koka-to, a Chinese herb, is a medicine prescribed to treat patients with hypertension. We investigated the effects of Shichimotsu-koka-to on the lesions of stroke-prone spontaneously hypertensive rats (SHRSP). The SHRSP were given 1% or 2% Shichimotsu-koka-to solution (1 g/kg/day or 2 g/kg/day) instead of drinking water from 8 to 42 weeks of age. When the 2 g/kg/day Shichimotsu-koka-to was chronically administered to the SHRSP, their life span was significantly prolonged by prevention of stroke, but there was no effect on blood pressure. The Shichimotsu-koka-to treatment decreased superoxide dismutase (SOD) activities in the cytosol of the cerebral cortex and increased SOD activities in the cytosol of the brain stem. The treatment with 2 g/kg/day Shichimotsu-koka-to decreased xanthine oxidase (XOD) activities in the cytosol of the cerebral cortex, and Shichimotsu-koka-to quenched superoxide anion (O2-) as determined by electron spin resonance analysis in vitro. In addition, SOD activities in the cytosol of the cerebral cortex of SHRSP not administered Shichimotsu-koka-to were increased by the drug in vitro. XOD activities in the cytosol of the cerebral cortex of SHRSP not administered Shichimotsu-koka-to were inhibited by this herb in vitro. These results suggest that these preventive effects of Shichimotsu-koka-to on the stroke in SHRSP are due its ability to scavenge O2- and to inhibit O2- production by the hypoxanthine-XOD system in the cytosol of the cerebral cortex.

High-resolution crystal structures of two polymorphs of cytochrome c' from the purple phototrophic bacterium rhodobacter capsulatus

The structures of two polymorphs of cytochrome c' from Rhodobacter capsulatus (RCCP) strain M110 have been determined by the molecular replacement method. Iron anomalous scattering data were used to confirm the molecular replacement solution. The structures were refined at 1.72 angstrom and 2.0 angstrom resolution to R-values of 15.0% and 16.3%, respectively. The RCCP molecule is a dimer and each of the identical 129 residue subunits folds as a four-helical bundle with a covalently bound heme group in the center. This structural motif resembles that of cytochromes c' reported from Rhodospirillum molischianum (RMCP), Rhodospirillum rubrum (RRCP), Chromatium vinosum (CVCP), Achromobacter xyloseoxidans (AXCP) and Alcaligenes denitrificans (ADCP). However, the architecture of the RCCP dimer, that is, the mode of association of subunits, differs substantially from that of the other cytochromes c'. In the RCCP dimer, the subunits are roughly parallel with each other and only helix B of each subunit participates in formation of the dimer interface. Measurement of the solvent-accessible surface area indicates that the dimer interface is smaller in RCCP than in the other cytochromes c'. In RMCP, CVCP, RRCP, AXCP and ADCP the subunits cross each other to form an X shape, and two helices, A and B, of each subunit interact across the dimer interface. These results are consistent with hydrodynamic measurements, which show that there is an equilibrium between monomers and dimer in RCCP, whereas the dimer is the predominant form in the other cytochromes c' for which structures have been determined. Structural comparison of the six cytochromes c' reveal that they can be divided into two groups. In group 1 cytochromes c', CVCP and RCCP, the amino acid sequences and the folding of subunits are arranged in such a way as to allow the formation of a deep channel between helices B and C with direct solvent accessibility to the heme sixth ligand position. There is no such channel in group 2 cytochromes c', RMCP, RRCP, AXCP and ADCP. This may account, in part, for the differences in carbon monoxide binding.