A mutation study of the DNA binding domain of human papillomavirus type11 E2 protein

A site-specific mutation study was performed on the C-terminal domain, containing a cloned DNA binding region, of the human papillomavirus type11 (HPV11) E2 protein to determine the specific properties of residues directly involved in the DNA binding. The effect of a point mutations on the DNA binding was assessed by means of a gel mobility shift assay. The mutagenesis was concentrated on the residues in the third helix from the N-terminal, that is known as the "recognition helix," in the crystal structure of the bovine papillomavirus (BPV) E2 protein. Most point mutations caused a great decrease in the DNA binding activity. The leucine repeat in the DNA binding region was proved not to be a leucine prerequisite, as the leucines could be substituted by valine without significant loss of the DNA binding ability. Substitution of Leu for Glu caused a significant decrease in the DNA binding, indicating that the hydrophobicity of the residue at this position is important. The results suggest that the individual contribution of each amino acid residue in the DNA binding region is essential for the DNA binding.

Immunohistochemical localization of extracellular matrix components in human breast tumours with special reference to PG-M/versican

Immunohistochemical localization of the large proteoglycan, PG-M/versican, was studied in 36 breast tumours, including infiltrating ductal carcinomas, benign tumours and fibrocystic diseases. The relation between the proteoglycan and the other extracellular matrix components was also investigated. In the carcinoma tissues, the interstitial elements of the 'specific stroma', consisting of fibroblastic cells and fine fibrils, were reactive to antibody 2B1, which specifically recognizes the large proteoglycan, PG-M/versican. In the peripheral invasive areas of infiltrating ductal carcinoma, the most intense 2B1-positive reaction was visualized in mesenchymal tissues between carcinoma cells clumps and the surrounding tissues, where hyaluronic acid could be demonstrated histochemically. The 2B1-positive elements were not reactive to antibody 6B6, which specifically recognizes small proteoglycan. In the central sclerotic areas, where antibody 6B6 was reactive, a 2B1-positive reaction was detected only in elastosis masses, which also bound antibodies to type IV collagen and laminin, and to some extent antibody raised against chondroitin 6-sulphate proteoglycan. Elastic tissues of blood vessel walls and perivascular elements became reactive to antibody 2B1 when they were involved in carcinoma invasion. The present results have shown that PG-M/versican was localized in the proliferating interstitial tissues, in particular in hyaluronic acid-rich portions, in association with carcinoma cell growth, and also that PG-M/versican accumulated in vascular and perivascular elastic tissues involved in carcinoma invasion. The biological significance of PG-M/versican was briefly discussed.

Suppressed cardiac and electroencephalographic arousal on apnea/hypopnea termination in elderly patients with cerebral infarction

The goal of the present investigation is to show the clinical significance of arousal response at termination of apnea/hypopnea in patients with sleep apnea syndrome (SAS) after cerebral infarction. We polygraphically assessed "cardiac arousal," which is defined as an abrupt increase in heart rate at a termination of sleep apnea/hypopnea, and electroencephalographic (EEG) arousal. There were six elderly subjects, bedridden after cerebral infarction, with SAS aged 71-87 years (mean 72.3 years) and 11 age-matched patients with SAS aged 61-78 years (mean 62.3 years) as controls. The following sleep parameters were measured: number of apneas per hour (apnea index [AI]), number of hypopneas per hour (hypopnea index [HI]), summation of the two (apnea/hypopnea index [AHI]), and duration in which nocturnal oxygen saturation was decreased below 90% (duration of SaO2 < 90%). We calculated the ratio of apnea/hypopnea per hour with cardiac arousal to total apnea/hypopneas (XI) (% cardiac arousal [XI/AHI x 100]) and the ratio of that with EEG arousal (YI) (% EEG arousal [YI/AHI x 100]). Between the two groups, we found no significant difference in body mass index, the ratio of central apnea to total apnea/hypopnea, AHI, duration of apnea/hypopnea, lowest SaO2, and duration of SaO2 < 90%. Compared with controls, % cardiac and % EEG arousals were significantly lower in patients with cerebral infarction. In contrast, the ratio of HI to AHI was significantly higher in patients with cerebral infarction than in control subjects. Our findings indicate that cardiac and EEG arousals at termination of apnea/hypopnea are significantly suppressed in elderly patients with SAS after cerebral infarction, which may provide useful information on the pathophysiology of SAS in patients with cerebrovascular disease.

Giant cell-rich osteosarcoma: a case report

This report discusses a rare case of giant cell-rich osteosarcoma. The patient, a 19-year-old male, was diagnosed with a metadiaphyseal osteolytic lesion when he consulted a local doctor complaining of motion pain without swelling. Radiography revealed a geographic osteolytic lesion, cortical thinning and ballooning without obvious cortical destruction. However, a fine onion skin-like periosteal reaction was observed on the lateral side of the femur. The transitional none was narrow and endosteal scalloping was also noted. Needle biopsied material clearly showed nuclear atypism of the stromal tumor cells with numerous osteoclast-like giant cells. Using a combination of pathological examination, radiography, computed tomography (CT) and magnetic resonance imaging (MRI), a diagnosis of giant cell-rich osteosarcoma was reached. After chemotherapy, resection and limb salvage surgery with an autogeneous autoclaved bone graft, a vascularized fibular graft were performed, and the patient has shown excellent limb function without local recurrence or distant metastasis during the past 72 months.

Dis3, implicated in mitotic control, binds directly to Ran and enhances the GEF activity of RCC1

Using the two-hybrid method, we isolated a Saccharomyces cerevisiae cDNA encoding a protein homologous to Schizosaccharomyces pombe protein Dis3sp, using as bait, human GTPase Ran. The DIS3 gene is essential for viability and complements S.pombe mutant dis3-54 which is defective in mitosis. Although Dis3sc has no homology to RanBP1, it bound directly to Ran and the S.cerevisiae Ran homologue Cnr1, but not to the S.cerevisiae RCC1 homologue Srm1. Upon binding to Ran with a 1:1 molar ratio, Dis3sc enhanced a nucleotide-releasing activity of RCC1 on Ran. In the presence of Dis3sc, the K(m) of RCC1 on Ran decreased by half, while the kcat was unchanged. In vivo, Dis3sp was present as oligomers of M(r) 670-200 kDa as previously reported, and the 200 kDa oligomer of Dis3sp was found to include Spi1 and Pim1, the S.pombe homologues of Ran and RCC1, respectively. Although the biological function of the heterotrimeric oligomer consisting of Dis3, Spi1 and Pim1 is unknown, our results indicate that Dis3 is a component of the RCC1-Ran pathway.

Acinic cell Carcinoma of the parotid gland: CT and MRI

We report CT and MRI bindings in two cases of acinic cell carcinoma of the parotid glands which behaved differently on T2-weighted images. Differences in signal intensities were considered to reflect the histology of the lesion, although a histological diagnosis could not be made on imaging grounds alone.

Putative GTPase Gtr1p genetically interacts with the RanGTPase cycle in Saccharomyces cerevisiae

In order to identify a protein interacting with RCC1, a guanine nucleotide-exchange factor for the nuclear GTPase Ran, we isolated a series of cold-sensitive suppressors of mtr1-2, a temperature-sensitive mutant of the Saccharomyces cerevisiae RCC1 homologue. One of the isolated suppressor mutants was mutated in the putative GTPase Gtr1p, being designated as gtr1-11. It also suppressed other alleles of mtr1-2, srm1-1 and prp20-1 in contrast to overexpression of the S. cerevisiae Ran/TC4 homologue Gsp1p, previously reported to suppress prp20-1, but not mtr1-2 or srm1-1. Furthermore, gtr1-11 suppressed the rna1-1, temperature-sensitive mutant of the Gsp1p GTPase-activating protein, but not the srp1-31, temperature-sensitive mutant of the S. cerevisiae importin alpha homologue. mtr1-2, srm1-1 and prp20-1 were also suppressed by overexpression of the mutated Gtr1p, Gtr1-11p. In summary, Gtr1p that was localized in the cytoplasm by immunofluoresence staining was suggested to function as a negative regulator for the Ran/TC4 GTPase cycle.

Mucinous carcinoma of the ovary. Clinicopathologic analysis

Since the incidence of mucinous carcinoma of the ovary is relatively low, with only small numbers of cases at any institution, detailed clinicopathologic studies on the prognosis and the care of patients with mucinous carcinoma are missing. Forty-four patients with mucinous carcinoma were histopathologically subclassified into endocervical (n = 8) and intestinal types (n = 36), and studied for clinical manifestations. All tumors of the endocervical type were stage I, whereas 14 intestinal-type tumors were stage II or higher (p < 0.05). Stromal invasion was not observed in 14 of 44 tumors, 13 of which were stage I. Analysis of prognostic factors disclosed that the clinical stage, maximum residual tumor diameter, volume of ascites, stromal invasion, and preoperative CA125 and CA19-9 levels significantly affected prognosis. However, multivariate analysis (stepwise regression) showed that the only significant factor was clinical stage (p < 0.004). In conclusion it is believed that, pathologically, the endocervical-type mucinous carcinoma is not as aggressive as the intestinal-type cancer. The clinical stage was found to be a significant prognostic factor even by multivariate analysis, and the prognosis at stages III and IV was unfavorable compared to stages I and II.

Characterization of polydnavirus-encoded mRNA in parasitized armyworm larvae

We have isolated five cDNA clones encoding Cotesia kariyai polydnavirus (CkPDV) mRNAs transcribed in parasitized host larvae of Pseudaletia separata. One of the cDNAs encoding the longest 2.0 kb CkPDV mRNA was sequenced and characterized. Southern hybridization analyses using the cloned cDNA as a probe showed that CkPDV mRNA was homologous to one of CkPDV DNA segments, 5.6 kbp DNA segment A. The 2.0-kb mRNA was demonstrated as being expressed in the parasitized host larvae by Northern-blot analyses. When specific host tissues were examined, the 2.0-kb mRNA was detected mainly in haemocytes. This RNA increased in relative abundance after 2 and 4 h post-parasitization when the immune response of host haemocytes appeared compromised.

Evaluation of immunochromatographic assay systems for rapid detection of hepatitis B surface antigen and antibody, Dainascreen HBsAg and Dainascreen Ausab

We evaluated two immunochromatographic assays (ICAs), Dainascreen HBsAg for detecting human hepatitis hepatitis B surface antigen (HBsAg) and Dainascreen Ausab for detecting human hepatitis B surface antibody (anti-HBs) in human serum. The ICA systems are composed of a comb-shaped device that contains nitrocellulose strips on which complexes of HBsAg and anti-HBs can be visualized. The results can be read within 15 min of incubation. The limit of detection for HBsAg was 3.1 ng/ml and that for anti-HBs was 42 mIU/ml. Results of HBsAg detection agreed completely with those of conventional enzyme immunoassays (EIAs) and showed a 100% sensitivity (158 of 158 samples) and a 100% specificity (304 of 304 samples). The Dainascreen Ausab detected 184 of the 199 EIA-positive samples (sensitivity, 92.5%) and yielded 6 positive results among the 281 EIA-negative samples (specificity, 97.9%). The ICA systems are rapid and sensitive methods for detecting HBsAg and anti-HBs. They are low-cost systems that need no complex instrumentation for analysis and can be recommended for routine use in clinical microbiology laboratories.

Point mutations of the c-Ki-ras gene in carcinoma and atypical epithelium associated with congenital biliary dilation

OBJECTIVES

Congenital biliary dilation (CBD) may be accompanied later by gallbladder carcinoma or bile duct carcinoma. These cancerous lesions are frequently associated with atypical epithelium that was suspected of being precancerous. To determine whether atypical epithelium may be precancerous, we examined the DNA sequence of the c-Ki-ras gene at codon 12 in nine cases of CBD concurrent with seven gallbladder carcinomas, one bile duct carcinoma, and one bile duct atypical epithelium.

METHODS

Tumor specimens were surgically removed from nine patients with CBD at Nagoya University Hospital between 1979 and 1988. Tumor was isolated by microdissection, and DNA was amplified by a two-step polymerase chain reaction which then was directly sequenced.

RESULTS

Four of seven gallbladder carcinomas and one bile duct carcinoma contained the c-Ki-ras point mutation at codon 12, and atypical epithelium associated with these carcinomas had the same mutation. One case of atypical bile duct epithelium also contained the mutation.

CONCLUSIONS

These results indicate that the c-Ki-ras point mutation at codon 12 may be responsible for either cancer or atypical epithelia associated with CBD.

Detection of apoptosis in human endometriotic tissues

To clarify whether apoptosis is involved in endometriosis, we obtained eutopic endometrial tissues along with endometriotic tissues from the uterus (adenomyosis) (n = 12) and from the ovary (n = 12) from patients undergoing gynaecological surgery. Apoptosis-induced DNA fragmentation was detected by the TdT-mediated dUTP-biotin nick-end labelling method, and immunostaining with a monoclonal antibody against the Fas, Le(y) or B-cell leukaemia/lymphoma-2 (bcl-2) was also performed using the same tissue section. Analysis showed that apoptosis was occurring in all the samples of ovarian endometriotic tissue but in only two of the 12 adenomyotic and in five of the 24 eutopic endometrial tissue samples. In none of these cases was apoptosis correlated with phases of the menstrual cycle. The expression of bcl-2 in the eutopic endometrial and adenomyotic tissues was limited to the proliferative phase, and was observed in only one of the 12 cases of ovarian endometriosis. Fas and Ley were expressed randomly across a wide range in both the eutopic and ectopic endometrial tissues. These results suggest that the features of ovarian endometriosis are different from those of adenomyosis and eutopic endometrium in terms of the involvement of apoptosis. In addition, the regulatory mechanism involved in ovarian endometriosis may differ from that in other endometrial cells.

Types of methicillin-resistant Staphylococcus aureus associated with high mortality in patients with bacteremia

Forty-seven strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from 47 patients with bacteremia were analyzed by chromosomal DNA digestion pattern using pulsed-field gel electrophoresis and evaluated for serological coagulase type, enterotoxin type, and toxic shock syndrome toxin-1 production. The mortality rate was significantly higher in the older patients (> or = 51 years of age) than in the younger patients (< or = 50 years of age) (50% vs. 4%, p = 0.0007). Methicillin-resistant Staphylococcus aureus strains of serological coagulase type II were more likely to be associated with mortality in older patients than were strains of the other types (p = 0.037).

Comparison of DNA fingerprinting by PFGE and PCR-RFLP of the coagulase gene to distinguish MRSA isolates

Staphylococcus aureus isolates were collected from epidemiologically unrelated clinical sources in Japan between 1991 and 1993. A total of 40 isolates, five each of eight coagulase types, were analysed by polymerase chain reaction (PCR) of the coagulase gene, PCR-restriction fragment length polymorphism (RFLP) after AluI digestion, and pulsed-field gel electrophoresis (PFGE) of chromosomal DNA after SmaI digestion. The efficiency of discrimination among the isolates increased in the order of PCR < PCR-RFLP < PFGE, yielding five, 13 and 31 different types, respectively. To assess the clinical use of these methods, 42 additional methicillin-resistant S. aureus (MRSA) isolates collected from 27 inpatients in a hospital were analysed. PFGE and PCR-RFLP were able to discriminate 11 and four types, respectively. PFGE analysis detected cross-infection between four postoperative patients in an intensive-care unit, and in six neonates in intensive care. We conclude that of the three methods tested, PFGE analysis currently allows the most effective discrimination of MRSA strains.

T cells bound by vascular cell adhesion molecule-1/CD106 in synovial fluid in rheumatoid arthritis: inhibitory role of soluble vascular cell adhesion molecule-1 in T cell activation

Elevated levels of soluble vascular cell adhesion molecule-1 (sVCAM-1)/CD106 have been reported in synovial fluid (SF) from patients with rheumatoid arthritis (RA). In the present study, VCAM-1-positive lymphocytes were found in SF from RA patients. The data strongly suggest that sVCAM-1 might be bound to lymphocytes in SF. rsVCAM-1 in the fluid phase can bind to both SF lymphocytes and IL-2-dependent T cell lines with up-regulated expression and binding activity of VLA-4. Furthermore, proliferative responses of SF mononuclear cells (SFMC) with PHA, immobilized anti-CD3, or anti-CD2 and PMA were inhibited to various extents in the presence of rsVCAM-1, but only PMA-induced proliferative response of PBMC from normal individuals was inhibited notably in the presence of rsVCAM-1. rsVCAM-1 also drastically reduced IL-2 production of Jurkat leukemic T cells possessing high affinity VLA-4 with the stimulation of anti-CD3 and PMA, suggesting that the T cell hyporesponsiveness induced by rsVCAM-1 might stem from impairment of IL-2 production. These results indicate that sVCAM-1 provides a negative signal to T cell activation, probably by affecting the pathway of protein kinase C activation. Thus, binding of sVCAM-1 to SF lymphocytes might partly explain the anergic state of these lymphocytes.

T cells bound by vascular cell adhesion molecule-1/CD106 in synovial fluid in rheumatoid arthritis: inhibitory role of soluble vascular cell adhesion molecule-1 in T cell activation

Elevated levels of soluble vascular cell adhesion molecule-1 (sVCAM-1)/CD106 have been reported in synovial fluid (SF) from patients with rheumatoid arthritis (RA). In the present study, VCAM-1-positive lymphocytes were found in SF from RA patients. The data strongly suggest that sVCAM-1 might be bound to lymphocytes in SF. rsVCAM-1 in the fluid phase can bind to both SF lymphocytes and IL-2-dependent T cell lines with up-regulated expression and binding activity of VLA-4. Furthermore, proliferative responses of SF mononuclear cells (SFMC) with PHA, immobilized anti-CD3, or anti-CD2 and PMA were inhibited to various extents in the presence of rsVCAM-1, but only PMA-induced proliferative response of PBMC from normal individuals was inhibited notably in the presence of rsVCAM-1. rsVCAM-1 also drastically reduced IL-2 production of Jurkat leukemic T cells possessing high affinity VLA-4 with the stimulation of anti-CD3 and PMA, suggesting that the T cell hyporesponsiveness induced by rsVCAM-1 might stem from impairment of IL-2 production. These results indicate that sVCAM-1 provides a negative signal to T cell activation, probably by affecting the pathway of protein kinase C activation. Thus, binding of sVCAM-1 to SF lymphocytes might partly explain the anergic state of these lymphocytes.

An epithelioid cell type of amelanotic melanoma of the pinna in a Fischer-344 rat: a case report

An epithelioid cell type of spontaneous amelanotic melanoma in the pinna of an aged albino Fischer-344 (F-344) rat is described. When the rat was necropsied at 109 wk of age, the pinnal tumor was recognized as a white spherical mass of 4 mm in diameter. Histologically, the tumor was observed in the dermis and composed of large round or polyhedral epithelioid eosinophilic cells that were arranged in various-sized cell nests. Immunohistochemistry demonstrated that the tumor cells were positive for S-100 protein and vimentin but negative for keratin and a rat macrophage antigen. Ultrastructurally, a few single membrane-bound premelanosomes that were accompanied by many primary lysosome-like bodies containing very fine granules were present in the cytoplasm of the tumor cells. This study has disclosed that, in addition to spindle cell variants of amelanotic melanomas, an epithelioid cell type of amelanotic melanoma may occur spontaneously in the skin of F-344 rats.

Apocrine carcinoma vs. apocrine metaplasia with atypia of the breast. Use of aspiration biopsy cytology

OBJECTIVE

To solve the problem of diagnosing apocrine carcinoma (APCA) through distinguishing it from benign apocrine metaplasia with atypia (APMA).

STUDY DESIGN

The study group consisted of five histologically confirmed cases of uncommon infiltrating apocrine carcinoma and a case of noninfiltrating apocrine carcinoma of the breast by aspiration biopsy cytology. The control group consisted of 103 cases of benign apocrine metaplasia with no atypia (APMN), 4 cases of APMA and 34 cases of common-type adenocarcinoma that were encountered in 662 breast aspirations from 1988 to 1992 at Hekinan Municipal Hospital.

RESULTS

In APCA the average age of patients (65 +/- 17.7 SD)(mean +/- SD) was more than 20 years older than APMA, and APCA generally measured > or = 2 cm or more in diameter as compared to < or = 2 cm in APMA lesions. In APCA the apocrine cells had high cellularity, with the cells occur singly and with syncytia in the background. Numerous degenerated apocrine cells and characteristic cell detritus were found. APCA was also characterized by apocrine cells with more marked nuclear abnormalities, including hyperchromasia and irregular nuclear shape, frequently with irregular nucleoli; more nuclei measure > or = 12 micron in diameter than in APMA. These findings, however, were present only to a mild degree in APMA, if at all. APMA may coexist with APCA.

CONCLUSION

If APMA is diagnosed, an open biopsy should be performed to distinguish it from APCA.

Extrapancreatic nerve plexus invasion by carcinoma of the head of the pancreas. Diagnosis with intraportal endovascular ultrasonography

CONCLUSION

The intraportal endovascular ultrasonography (IPEUS) could diagnose the second portion of the extrapancreatic nerve plexus invasion and provide precise information in operative strategy. But, the first portion was not visualized clearly owing to poor tissue penetration of the ultrasound beam, which may have reduced diagnostic accuracy. Improvement of the scanning area is expected to make intraportal endovascular US even more useful.

BACKGROUND

Pancreatic cancer easily invades the retroperitoneal tissue, especially the extrapancreatic nerve plexus. We evaluated the extrapancreatic nerve plexus invasion of the pancreatic cancer with IPEUS. IPEUS was performed intraoperatively in 20 consecutive resected cases with carcinoma of the head of the pancreas.

METHODS

IPEUS was performed with an 8-French, 20 MHz intravascular ultrasound catheter. IPEUS visualized the inferior pancreaticoduodenal artery (IPDA) in the extrapancreatic nerve plexus. The high-echoic area around the IPDA corresponds to the second portion of the extrapancreatic nerve plexus. The sonographic criterion for detection of the extrapancreatic nerve plexus invasion is low-echoic infiltration around the IPDA.

RESULTS

Extrapancreatic nerve plexus invasion was confirmed with resected specimens in 10 patients. The IPDA could not be visualized in two patients. In 18 patients, the diagnostic accuracy of invasion was evaluated. For diagnosis of extrapancreatic nerve plexus invasion with intraportal endovascular US, the sensitivity, specificity, and overall accuracy were 87.5, 90, and 88.7%, respectively.

Complete nucleotide sequence of the Nilaparvata lugens reovirus: a putative member of the genus Fijivirus

The nucleotide sequences of all genome segments of the Nilaparvata lugens reovirus (NLRV), which is found in the brown planthopper Nilaparvata lugens, have been determined and some genes have been assigned to structural and functional proteins. The genome of NLRV consists of 28 699 nucleotides and contains at least 11 large open reading frames (ORFs). The genome of NLRV is the largest among viruses of the family Reoviridae reported to date. The deduced amino acid sequence of genome segment S1 contained the major motifs of RNA polymerase and that of S7 had the purine NTP-binding motif. Based on the molecular masses of the deduced proteins and the particle structure of NLRV, segments S1, S3 and S7 were assigned to the 160, 140 and 75 kDa proteins, respectively, that are located in the inner core. It was deduced that S2 codes for the 135 kDa protein (B spike), which is located on the surface of the inner core. Most reported ORFs of rice black streaked dwarf virus (RBSDV), which shares many properties with NLRV, had similarities with the corresponding ORFs of NLRV. An exception was S7 ORF2, which is found in RBSDV but not NLRV and may therefore be involved in multiplication of RBSDV in rice plants. These results and our previous observations indicate that NLRV should be classified in the genus Fijivirus.