DNA polymerase epsilon encoded by cdc20+ is required for chromosomal DNA replication in the fission yeast Schizosaccharomyces pombe

BACKGROUND

DNA polymerase II (PolII), the homologue of mammalian DNA polymerase epsilon, is essential for chromosomal DNA replication in the budding yeast Saccharomyces cerevisiae and also participates in S-phase checkpoint control. An important issue is whether chromosomal DNA replication in other eukaryotes, including the fission yeast Schizosaccharomyces pombe--in which the characteristics of replication origins are poorly defined--also requires DNA polymerase epsilon. It has been shown that DNA polymerase epsilon is not required for the in vitro replication of SV40 DNA by human cell extracts.

RESULTS

We have cloned and sequenced S. pombe pol2+, which is identical to the cell-cycle gene cdc20+, encoding the catalytic polypeptide of DNA polymerase epsilon (Pol epsilon). The predicted amino acid sequence of Pol epsilon is highly homologous to that of S. cerevisiae PolII and human Pol epsilon. Consistent with this, the Pol epsilon polypeptide was recognized by polyclonal antibodies against S. cerevisiae PolII holoenzyme (PolII*). The terminal morphology of cells containing the disrupted pol2 gene was similar to that of DNA replication mutant cells and cdc20 mutant cells. Furthermore, the Pol epsilon activity from temperature-sensitive S. pombe cdc20 mutant cells was temperature-sensitive, and chromosomal DNA replication in the mutant cells was inhibited at the restrictive temperatures.

CONCLUSION

These data strongly suggest that Pol epsilon is required for normal chromosomal DNA replication in S. pombe, as is PolII in S. cerevisiae. Thus, eukaryotic chromosomal DNA is replicated differently from that of viral SV40 DNA.

The second subunit of DNA polymerase III (delta) is encoded by the HYS2 gene in Saccharomyces cerevisiae

DNA polymerase III (delta) of Saccharomyces cerevisiae is purified as a complex of at least two polypeptides with molecular masses of 125 and 55 kDa as judged by SDS-PAGE. In this paper we determine partial amino acid sequences of the 125 and 55 kDa polypeptides and find that they match parts of the amino acid sequences predicted from the nucleotide sequence of the CDC2 and HYS2 genes respectively. We also show by Western blotting that Hys2 protein co-purifies with DNA polymerase III activity as well as Cdc2 polypeptide. The complex form of DNA polymerase III activity could not be detected in thermosensitive hys2 mutant cell extracts, although another form of DNA polymerase III was found. This form of DNA polymerase III, which could also be detected in wild-type extracts, was not associated with Hys2 protein and was not stimulated by addition of proliferating cell nuclear antigen (PCNA), replication factor A (RF-A) or replication factor C (RF-C). The temperature-sensitive growth phenotype of hys2-1 and hys2-2 mutations could be suppressed by the CDC2 gene on a multicopy plasmid. These data suggest that the 55 kDa polypeptide encoded by the HYS2 gene is one of the subunits of DNA polymerase III complex in S.cerevisiae and is required for highly processive DNA synthesis catalyzed by DNA polymerase III in the presence of PCNA, RF-A and RF-C.

Association of a polymorphism of the endothelial constitutive nitric oxide synthase gene with myocardial infarction in the Japanese population

We investigated the association between variations in the endothelial constitutive nitric oxide synthase (ecNOS) gene and the presence of myocardial infarction. The results indicate that the mutant allele (ecNOS'4a) is an independent risk factor for myocardial infarction in the Japanese population, especially in those lacking other conventional risk factors.

Differential effects of intrathecally administered delta and mu opioid receptor agonists on formalin-evoked nociception and on the expression of Fos-like immunoreactivity in the spinal cord of the rat

This study examined the effects of intrathecally (i.t.) administered mu and delta opioid receptor agonists on the flinching behavior and the expression of Fos-like immunoreactivity (Fos-LI) in the spinal cord elicited by s.c. injection of 5% formalin in one hindpaw of the rat. Intrathecal pretreatment with either the delta-1 opioid receptor agonist [D-Pen2,5]enkephalin (DPDPE) or the delta-2 opioid receptor agonist [D-Ala2,Glu4]deltorphin (DELT) produced a dose-dependent inhibition of flinching behavior in phase 1 and phase 2 that was antagonized by coadministration of the delta-1 opioid receptor antagonist 7-benzylidinenaltrexone or the delta-2 opioid receptor antagonist Naltriben, respectively. Although i.t. pretreatment with 60 micrograms of DPDPE produced a small decrease in the numbers of Fos-LI neurons in laminae I, IIi and IIo, as well as laminae V and VI and laminae VII-X, i.t. pretreatment with 30 micrograms of DELT did not decrease the number of Fos-LI neurons in any region of the spinal cord. In contrast, i.t. pretreatment with an equieffective dose of the mu opioid receptor agonist [D-Ala2,NMePhe4,Gly-ol5]enkephalin (DAMGO) not only significantly decreased the number of flinches in phase 1 and phase 2, but also nearly completely prevented the expression of Fos-LI in all regions of the spinal cord. These effects were antagonized by pretreatment with the mu opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Phe-Thr-NH2. The efficacy of i.t. administered DAMGO suggests that a direct spinal action contributes to the inhibition of noxious stimulus-evoked Fos-LI in the spinal cord produced by systemically administered mu opioid receptor agonists such as morphine. The relative lack of effect of DPDPE or DELT suggests that delta opioid receptors do not modulate the early-immediate gene c-fos. Alternatively, because delta opioid receptor agonists inhibit synaptic transmission in the spinal cord by predominantly presynaptic mechanisms and do not hyperpolarize dorsal horn neurons, the excitatory inputs that persist in the presence of these agonists may be sufficient to activate the c-fos gene. Taken together, these results provide new evidence, at the level of a "third messenger," that the antinociception produced by i.t. administration of delta and mu opioid receptor agonists is mediated by different mechanisms.

RagA is a functional homologue of S. cerevisiae Gtr1p involved in the Ran/Gsp1-GTPase pathway

Human RagA and RagB is reported to be 52% identical to a putative GTPase of Saccharomyces cerevisiae, Gtr1p. According to the reported nucleotide sequence, we amplified human RagA and RagBs cDNAs from the human B cell cDNA library with PCR. Both cDNAs rescued a cold sensitivity of S. cerevisiae, gtr1-11. Furthermore, we introduced into the cloned human RagA cDNA, the mutation ‘T21L’ corresponding to the gtr1-11 mutation which has been reported to suppress not only all of rcc1-, temperature-sensitive mutants of Ran/Gsp1p GTPase GDP/GTP-exchanging factor, but also rna1-1, a temperature-sensitive mutant of Ran/Gsp1p GTPase-activating protein. The resulting RagAgtr1-11 cDNA partially, but significantly, suppressed both rcc1- and rna1-1 mutations. These results indicated that RagA and RagBs are functional homologues of S. cervisiae Gtr1p. Interestingly, while wild-type human RagA and RagBs were localized within the cytoplasm, similar to S. cerevisiae Gtr1p, the mutated human RagAgtr1-11 corresponding to a dominant negative form of RagA was distributed in discrete speckles in the nucleus, being localized side by side with SC-35, a non-snRNP of the splicing complex. In contrast, a dominant positive form of RagA, Q66L was localized in the cytoplasm. Thus, RagA was suggested to shuttle between the cytoplasm and the nucleus, depending on the bound nucleotide state.

Lack of association of angiotensin converting enzyme gene polymorphism or serum enzyme activity with coronary artery disease in Japanese subjects

The association of an insertion/deletion (I/D) polymorphism in the angiotensin converting enzyme (ACE) gene or the serum activity of ACE with coronary artery disease (CAD) was investigated in Japanese men and women. The ACE genotype of 947 CAD subjects who underwent coronary angiography and of 893 control subjects was determined by polymerase chain reaction analysis. No association of the DD genotype or the D allele with CAD was observed in men or women. In a low risk group (defined by a body mass index below the median value and the absence of a history of hypertension, diabetes mellitus, and hypercholesterolemia), there was also no association between the ACE gene polymorphism and CAD. No significant difference in serum ACE activity was detected between CAD subjects and controls of all genotypes or of the same genotype, whereas a significant association was apparent between serum ACE activity and ACE genotype for both CAD subjects and controls among both men and women. These results indicate that the ACE I/D polymorphism and genotype associated variation in serum ACE activity are not risk factors for CAD in Japanese men or women.

Diagnostic value of the strand displacement amplification method compared to those of Roche Amplicor PCR and culture for detecting mycobacteria in sputum samples

We compared the ability of the semiautomated BDProbeTec-SDA system, which uses the strand displacement amplification (SDA) method, with that of the Roche Amplicor-PCR system and the Septi-Chek AFB culture system to directly detect Mycobacterium tuberculosis complex (MTB) and other mycobacteria in sputum samples. A total of 530 sputum samples from 299 patients were examined in this study. Of the 530 samples, 129 were culture positive for acid-fast bacilli with the Septi-Chek AFB system; 95 for MTB, 29 for M. avium-M. intracellulare complex (MAC), and 5 for other mycobacteria. The BDProbeTec-SDA system detected 90 of the 95 samples culture positive for MTB (sensitivity, 94.7%), and the Amplicor-PCR system detected 85 of the 95 samples culture positive for MTB (sensitivity, 89.5%). The specificity of each system, based on the clinical diagnosis, was 99.8% for SDA and 100% for PCR, respectively. Among the 29 samples culture positive for MAC, the BDProbeTec-SDA system detected MAC in 24 samples (sensitivity, 82.8%), whereas the Amplicor-PCR system detected MAC in 23 samples (sensitivity, 79.3%). The specificities of the systems were 98.3 and 100%, respectively. The high degrees of sensitivity and specificity of the BDProbeTec-SDA system suggest that it should be very useful in clinical laboratories for the rapid detection of mycobacteria in sputum samples.

Gorham massive osteolysis

Gorham syndrome (massive osteolysis) is a very rare tumour-like lesion characterized by progressive osteolysis. The diagnosis must be confirmed by the microscopic finding of intramedullary angioma-like vascular structures. We report a case of a 15-year-old boy with a pathological fracture in his left humerus. Imaging modalities such as magnetic resonance imaging, computed tomography, angiography and bone scintigraphy failed to disclose to tumorous lesion that filled a cavity in the left humerus. After observing the boy's progress for 6 months, a temporary diagnosis of Gorham syndrome was made, and surgical treatment was chosen. After resection of the left humeral head and the proximal one-quarter of the humerus, thorough curettage was performed in the distal humerus and an intramedullary artificial humeral head fixed with adequate success. Pathological examination of the specimen revealed intramedullary haemangioma of the humerus.

Kinetic assay of serum and urine for urea with use of urease and leucine dehydrogenase

We describe a new kinetic assay for determining urea in serum or urine with use of urease (EC 3.5.1.5) and leucine dehydrogenase (EC 1.4.1.9). The latter enzyme is suitable for the kinetic assay of NH4+ because its Km value for NH4+ at pH 8.75 is large (approximately 500 mmol/L). Interference from endogenous NH4+ in serum or urine is obviated by subtraction of the assayed endogenous NH4+ value in a sample blank. For serum, within-assay CVs (n = 10) were 0.39-0.58%; day-to-day CVs (n = 10) were 1.56-2.30%. In urine, within-assay CVs (n = 10) were 0.86-1.15%. Analytical recovery of urea (0.893-71.4 mmol/L) added to patients' sera (urea 6.14 mmol/L) was 99.2-105.2%. The calibration curve for serum was linear through zero for urea concentrations up to 142.9 mmol/L and for urine up to 714.3 mmol/L. No influences of added ammonium ion, bilirubin, hemoglobin, ascorbic acid, or Intralipid were observed. The regression equations for this method (y) and conventional methods (x = Determiner-LUN for serum assays, Serotec UUR-R for urine) were: y = 1.016x - 0.12 mmol/L (r = 0.999, S(y/x) = 0.34 mmol/L, n = 100) for sera, and y = 1.070x - 12.6 mmol/L (r = 0.998, S(y/x) = 7.41 mmol/L, n = 100) for urine.

Lymph node metastasis in carcinoma of the body and tail of the pancreas

BACKGROUND

There have been no precise reports concerning lymph node metastatic involvement in carcinoma of the body and tail of the pancreas.

METHODS

Histopathological examination of lymph node involvement in 30 specimens obtained from patients who underwent pancreatic resection and wide dissection of lymph nodes, including para-aortic lymph nodes, for carcinoma of the body and tail of the pancreas was performed.

RESULTS

Fourteen of 30 patients had lymph node involvement. The highest incidence of lymph node involvement was around the splenic artery (five of 30 patients), aorta (four of 30) and coeliac trunk (four of 30). No significant difference in survival rate between the lymph node-negative group and the lymph node-positive group was observed, but all patients in the positive group died within 2 years after surgery, and four patients with para-aortic lymph node involvement died from recurrence within 10 months after surgery. Survival rates were significantly worse in patients with histopathological extrapancreatic nerve plexus invasion, retropancreatic tissue invasion, tumour diameter more than 4 cm, histological portal system vein wall invasion and carcinoma invasion of the surgical margins.

CONCLUSION

Although aggressive extended surgery including para-aortic node dissection has been performed, the postoperative survival rate is still low in patients with carcinoma of the body and tail of the pancreas. The high incidence of liver metastasis after surgery is a prime cause of the poor outcome, and effective therapy for postoperative liver recurrence requires evaluation.

Histological evaluation of connective tissue components in the healing process of human gastric ulcer

1. The aim of the present study was the evaluation of human gastric ulcer healing and intractability from the viewpoint of connective tissue components. 2. Based on investigations of clinical status, we divided 78 patients with a gastric ulcer into three groups. All patients underwent gastrectomy and group I consisted of 17 patients operated on for bleeding or perforation, group II consisted of 37 patients operated on for an accompanying gastric carcinoma and group III consisted of 24 patients operated on for ulcer intractability. 3. We evaluated, in resected specimens, angiogenesis by Azan-Mallory staining and fibroplasia by applying proliferating cell nuclear antigen (PCNA) immunostaining. The inflammatory grade and fibrosis at the ulcer base were also evaluated by haematoxylin-eosin and Azan-Mallory staining. 4. Microvessel counts in group III were significantly lower than those in group I and II (P < 0.05). The PCNA labelling index of fibroblasts in group III was significantly lower than that in groups I and II (P < 0.05). The inflammatory grade was severe and fibrosis was excessive in group III. 5. From these results, it is suggested that the reduced angiogenesis and decline in fibrous cell proliferation are important factors contributing to gastric ulcer intractability.

Lack of association between variants of the angiotensinogen gene and the risk of coronary artery disease in middle-aged Japanese men

The renin-angiotensin system is important in cardiovascular remodeling. Although a variant of the angiotensinogen gene is associated with an increased generation of angiotensinogen, it is unclear how this genetic variant might influence the activity of the renin-angiotensin system and thereby contribute to the predisposition to coronary artery disease (CAD). The relation between genetic polymorphisms in the gene-encoding angiotensinogen and the risk of CAD in middle-aged Japanese men was investigated. Two polymorphisms in exon 2 of the angiotensinogen gene, M235T and T174M, were analyzed in 327 patients with CAD and 352 matched control subjects. The genotype distribution of both polymorphisms did not differ between patients with CAD and control subjects. No combination of genotypes of the two polymorphisms was associated with CAD. Results indicate that the M235T and T174M variants of the angiotensinogen gene are not associated with CAD in Japanese men.

Lymph node metastasis in carcinoma of the body and tail of the pancreas

BACKGROUND

There have been no precise reports concerning lymph node metastatic involvement in carcinoma of the body and tail of the pancreas.

METHODS

Histopathological examination of lymph node involvement in 30 specimens obtained from patients who underwent pancreatic resection and wide dissection of lymph nodes, including para-aortic lymph nodes, for carcinoma of the body and tail of the pancreas was performed.

RESULTS

Fourteen of 30 patients had lymph node involvement. The highest incidence of lymph node involvement was around the splenic artery (five of 30 patients), aorta (four of 30) and coeliac trunk (four of 30). No significant difference in survival rate between the lymph node-negative group and the lymph node-positive group was observed, but all patients in the positive group died within 2 years after surgery, and four patients with para-aortic lymph node involvement died from recurrence within 10 months after surgery. Survival rates were significantly worse in patients with histopathological extrapancreatic nerve plexus invasion, retropancreatic tissue invasion, tumour diameter more than 4 cm, histological portal system vein wall invasion and carcinoma invasion of the surgical margins.

CONCLUSION

Although aggressive extended surgery including para-aortic node dissection has been performed, the postoperative survival rate is still low in patients with carcinoma of the body and tail of the pancreas. The high incidence of liver metastasis after surgery is a prime cause of the poor outcome, and effective therapy for postoperative liver recurrence requires evaluation.

[Evaluation of electrocardiographic left ventricular hypertrophy with both QRS voltage and ST-T change using echocardiography]

The purpose of the present study is to determine whether electrocardiographic QRS voltage criteria with ST-T change is useful in the diagnosis of left ventricular hypertrophy (LVH) using echocardiography. One hundred men including 59 with hypertension (HT), 9 with hypertrophic cardiomyopathy (HCM), and 32 without any cardiovascular disease were enrolled in this study. All of them had the electrocardiographic evidence of LVH by Sokolow-Lyon voltage criteria (RV5 or RV6 > 2.6 mV, SV1+RV5 or SV1+RV6 > or = 3.5 mV). They were classified into three groups based on ST-T pattern as follows: Normal ST-T (group N): normal ST-T in twelve leads; Early strain ST-T (group ES): ST depression, flat T (T/R < 1/10), diphasic T or T wave inversion < 0.1 mV in V5 or V6; and Strain ST-T (group S): inverted T wave in V5 and V6. Echocardiographic LVH was determined when either interventricular septal thickness (IVST) or left ventricular posterior wall thickness (LVPWT) > or = 12 mm was present. According to this echocardiographic evidence, 31.7%(20/63) of group N, 75.0% (12/16) of group ES, and 100% (21/21) of group S were diagnosed. There were significant correlations between QRS voltage indices (RV5, RV6, SV1+RV5 and SV1+RV6) and IVST, (IVST+LVPWT)/2, and LV mass in group S(r = 0.650 to 0.858, p < 0.05) but not in group N. Values for IVST and LV mass were significantly greater in group S than in group ES or N. The electrocardiographic diagnosis of LVH with both QRS voltage and ST-T change thus appeared to be more useful than that with QRS voltage criteria alone.

Mycobacterium growth indicator tube testing in conjunction with the AccuProbe or the AMPLICOR-PCR assay for detecting and identifying mycobacteria from sputum samples

We have compared the ability of the Mycobacterium Growth Indicator Tube (MGIT) system, a new culture method with an oxygen-sensitive fluorescent sensor, to recover mycobacteria from sputum samples with the abilities of egg-based medium and the Septi-Chek AFB system. We have also assessed the clinical utility of the AccuProbe or the AMPLICOR-PCR assay to directly identify Mycobacterium tuberculosis complex and M. avium-M. intracellulare complex (MAC) from positive MGITs. From 382 sputum samples, 99 isolates of M. tuberculosis complex and 20 isolates of MAC were recovered. The MGIT system had the highest recovery rates for M. tuberculosis complex (97.0%) and MAC (100%), compared to recovery rates of 51.5 and 65.0%, respectively, with the egg-based medium and 81.8 and 85.0%, respectively, with the Septi-Chek AFB system. The shortest recovery times were also achieved with the MGIT system: 16.6 days for M. tuberculosis complex and 12.0 days for MAC, compared to 27.1 and 20.1 days, respectively, with the egg-based medium and 21.4 and 13.2 days, respectively, with the Septi-Chek AFB system. The AccuProbe identified 74 (77.1%) of the 96 M. tuberculosis complex-positive MGITs and 17 (85.0%) of the 20 MAC-positive vials. The AMPLICOR system correctly identified 94 (97.9%) of the 96 M. tuberculosis complex-positive MGITs and all 20 MAC-positive vials. Therefore, the MGIT system used in conjunction with the AMPLICOR system is a rapid and sensitive method for detecting and identifying M. tuberculosis complex and MAC isolates from sputum samples.

A randomized trial of cisplatin, vinblastine, and bleomycin versus cyclophosphamide, aclacinomycin, and cisplatin in epithelial ovarian cancer

After primary cytoreductive surgery, a randomized clinical trial was conducted in women with epithelial ovarian cancer to compare the impact on survival between PVB chemotherapy, consisting of cisplatin, vinblastine and bleomycin, and CAP chemotherapy, consisting of cyclophosphamide, aclacinomycin and cisplatin. There were 148 evaluable patients. One hundred and five patients with stage II, III and IV were analyzed in this study, 49 of them received PVB chemotherapy while the remaining 56 patients received CAP chemotherapy. Sixty-four patients fulfilled the criteria for clinical remission set by the Tokai Ovarian Tumor Study Group [Gynecol Oncol 1993;48:342-348]. The remission rate was 73 and 50% in the PVB and CAP groups, respectively, and showed a significant advantage for the PVB group (p = 0.0139). Moreover, the recurrence rate was 44% in the PVB group and 61% in the CAP group after clinical remission, although there was no significant difference between the two groups. The final survival rate was 32% in the PVB group and 24% in the CAP group. There was a significant difference of survival rate between both groups at 24 months (p = 0.0378) and 48 months (p = 0.0450), but finally no significant difference was found at 96 months (p = 0.0660). Compared to the CAP regimen, the PVB combination has a significantly higher efficacy in remission, but there was no significant difference in the long-term survival rate. Furthermore, multivariate analysis demonstrated that the PVB chemotherapy improved the survival, but it was not significant. The authors conclude that PVB chemotherapy may be more effective than CAP chemotherapy for epithelial ovarian cancer.

An investigation into the prevalence of thyroid disease on Kwajalein Atoll, Marshall Islands

The prevalence of thyroid nodules and thyroid cancer was studied in the indigenous population residing on Ebeye Island, Kwajalein Atoll, in the Republic of the Marshall Islands. This island, centrally located in the nation, is home to about 25% of the nation's population, many who have migrated there from other atolls. The objective of the study was to obtain thyroid disease rate statistics on as much of the population as possible that was alive during the years of nuclear testing and to test the hypothesis that described a linearly decreasing prevalence of palpable nodules with increasing distance from the Bikini test site. 1,322 Marshallese born before 1965 were given a thyroid examination using neck palpation, fine needle aspiration biopsy, and high resolution ultrasound imaging. Approximately 40% of the total population living on this island who are at risk from exposure to radioactive fallout during the years 1946-1958 were screened. Of that group, 815 were alive at the time of the BRAVO test on 1 March 1954. Two hundred sixty-six people with thyroid nodules were found (32.6%): 132 were palpable nodules (16.2%), and 134 were nodules that could be diagnosed with ultrasound only (15.7%). Prevalence of palpable nodules was particularly high in men and women older than 60 y, in men who were 6 to 15 y of age at the time of the BRAVO test, and in women 1 to 10 y of age at the time of the BRAVO test. In 22 people, the clinical diagnosis was most likely cancer though histopathological evidence was only available from 11 operated cases. Of the 11 operated cases, 10 were cancer. Cancer prevalence was particularly high in those women born between 1944 and 1953 (7/220 = 3.2%), i.e., who were children during the early years of nuclear testing. The Ebeye data showed a marginally significant correlation between palpable nodule prevalence among women and distance to Bikini (r = -0.44, p = 0.06). This report summarizes the clinical findings of the thyroid examinations, the age distributions for nodular disease and cancer, and examines the relationship between prevalence of nodules and present day levels of 137Cs in the environment of each atoll.

Association of a deletion polymorphism of the angiotensin-converting enzyme gene with left-ventricular hypertrophy in Japanese women with essential hypertension; multicenter study of 1,919 subjects

The relationship of an insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene to left-ventricular hypertrophy in individuals with essential hypertension (EH) was investigated in a large population of Japanese men and women. The ACE genotype of 762 subjects with EH (425 men and 337 women) and 1,157 healthy controls (604 men and 553 women) was determined by polymerase chain reaction analysis. The distribution of ACE genotypes did not differ significantly between patients with EH and control in both men and women. For women with EH, the DD genotype was positively associated with the thickness of the interventricular septum and inversely associated with the left ventricular end-diastolic dimension, both determined by echocardiography. In contrast, the DD genotype was not associated with any echocardiographic parameter in men with EH. These results indicate that the DD genotype is a risk factor for left-ventricular hypertrophy in Japanese women with EH, but not for Japanese men.

Numerous vessels detected by CD34 in the villous stroma of complete hydatidiform moles

It has been considered that the villous stroma of complete hydatidiform moles (CHMs) is usually avascular. Vessels would normally form if embryogenesis had occurred. But judging by the structural maturity of molar villi, it was suspected that they must contain a considerable number of blood vessels and an attempt was made to demonstrate their presence. It has been shown previously that the vascular endothelial cell markers factor VIII related antigen (FVIII-RAg), Ulex europaeus 1 agglutinin (UEA-1) and CD31 were of no use in demonstrating the vessels in molar villi. A monoclonal antibody, QBEND/10, raised against the CD34 antigen in human endothelial cell membranes and hemopoietic progenitor cells, was selected to test its use as a marker of villous vascular endothelial cells in CHMs. On immunohistochemical analysis, numerous blood vessels were found using CD34 antibody in the stroma of CHMs, and the numbers corresponded to those found in normal villi of gestational age 8-12 weeks. Moreover, the luminal free surface of all vascular endothelial cells was so specifically delineated that it permitted the identification of vessels not apparent on hematoxylin- and eosin-stained sections; other stromal cells and trophoblast were not labeled.

Intraabdominal lymphangiosarcoma in a Fischer-344 rat

A Sarcoma arising in the abdominal cavity in an aged Fischer-344 rat was studied by immunohistochemistry and electron microscopy. The white-yellow soft mass was located on the lumbosacral vertebrae, compressing adjacent parenchymal organs. The tumor was made up of spindle shaped cells situated in a background of myxoid substance and a small amount of reticulin and collagen fibers. The tumor cells grew in a loose storiform pattern and often adhered to each other by their cell processes to form ovoid or slitlike spaces. Immunohistochemically, the tumor cells were strongly positive for vimentin but negative for keratin, macrophage ED1 antigen, alpha-smooth muscle actin, Factor VIII-related antigen, and S100 protein. Electron microscopy demonstrated the endothelial differentiation of the tumor cells, such as occasional luminal spaces, a small number of micropinocytotic vesicles, and interdigitating junctions with desmosomes between cell processes of adjacent cells. Furthermore, its endothelial origin was suggested by the presence of electron-dense rods resembling Weibel-Palade bodies. Instead of a definitive basement lamina surrounding the tumor cells, there were extracellular thin "anchoring filaments" that were attached to the cell surface at areas of increased electron density. These findings indicate that the tumor is of lymphatic vessel type rather than blood vessel type.

[Mitral valve prolapse and autonomic activity in normal women]

We examined relationships between mitral valve prolapse (MVP) and circadian rhythm of autonomic activity using spectral analysis of heart rate variability and echocardiography in 31 normal women. The heart rate variability was calculated from 24-hour ambulatory electrocardiogram by Fourier transformation. The power spectra were quantified at 0.04-0.15 Hz (low frequency power (LF) 1n (ms2)) and 0.15-0.40 Hz (high frequency power (HF) 1n (ms2)). The HF component and the ratio of LF/HF were used as indices of parasympathetic and sympathetic activity, respectively. MVP was present in 22.6%. There were no significant differences in left ventricular dimension between subjects with MVP (group MVP (+)) and subjects without MVP (group MVP(-)). Number of ventricular premature contractions in group MVP(+) tend to be higher compared with that in group MVP(-). The level of high frequency power at 0-5 am in group MVP(+) was significantly higher than that in group MVP(-), which parasympathetic activity during sleep in MVP(+) group was higher compared with that in group MVP(-). The evaluation of autonomic activity using spectral analysis of heart rate variability for 24-hour ambulatory electrocardiogram might provide useful information about the pathology of MVP.

Asymmetrical or heterogeneous enhancement of the internal jugular veins in contrast-enhanced CT of the head and neck

With faster CT scanners, asymmetric/heterogeneous enhancement (ASHE) of the internal jugular veins (IJVs) is frequently encountered in the absence of pathology. We investigated the frequency, side, pattern and significance of ASHE in 200 patients with various head and neck lesions. Non-ionic contrast medium (300 mgI/ml) was infused into a forearm vein (right, n = 100); left, n = 100). Forty seconds after contrast medium injection, contiguous 5-mm-thick sections were obtained craniocaudally from the skull base to the aortic arch. CT machines with two different scanning cycle times (3 s, n = 100; 2 s, n = 100) were used. ASHE of the IJVs was observed in 51 patients (25.5%); the patient group receiving a right-sided injection with a 2-s scan cycle machine, showing a higher frequency (44%). ASHE was divided into four patterns: homogeneous low density, focal low density, heterogenous opacification and fluid-fluid level formation. ASHE was frequently observed in routine contrast-enhanced CT of the head and neck. Frequency of ASHE increased when the scanning cycle was shorter. We should be aware of this phenomenon to avoid its misinterpretation as venous thrombosis or other pathology.

Yrb2p, a Nup2p-related yeast protein, has a functional overlap with Rna1p, a yeast Ran-GTPase-activating protein

The Ran-GTPase cycle is important for nucleus-cytosol exchange of macromolecules and other nuclear processes. We employed the two-hybrid method to identify proteins interacting with Ran and the Ran GTP/GDP exchange factor. Using PRP20, encoding the Ran GTP/GDP exchange factor, we identified YRB1, previously identified as a protein able to interact with human Ran GTP/GDP exchange factor RCC1 in the two-hybrid system. Using GSP1, encoding the yeast Ran, as bait, we isolated YRB2. YRB2 encodes a protein containing a Ran-binding motif similar to that found in Yrb1p and Nup2p. Yrb1p is located in the cytosol whereas Nup2p is nuclear. Similar to Yrb1p, Yrb2p bound to GTP-Gsp1p but not to GDP-Gsp1p and enhanced the GTPase-activating activity of Rna1p. However, unlike Yrb1p, Yrb2p did not inhibit the nucleotide-releasing activity of Prp20p. While overproduction of Yrb1p inhibited the growth of a mutant possessing a PRP20 mutation (srm1-1) and suppressed the rna1-1 mutation, overproduction of Yrb2p showed no effect on the growth of these mutants. Disruption of YRB2 made yeast cold sensitive and was synthetically lethal with rna1-1 but not with nup2delta. Nuclear protein import and the mRNA export were normal in strains possessing mutations of YRB2. We propose that Yrb2p is involved in the nuclear processes of the Ran-GTPase cycle which are not related to nucleus-cytosol exchange of macromolecules.

Determination of anti-streptolysin O antibody titer by a new passive agglutination method using sensitized toraysphere particles

We developed a new method for determining the anti-streptolysin O (ASO) titer on the basis of a passive agglutination reaction. This new method uses Toraysphere particles sensitized with streptolysin O. This method was used to measure the ASO titer in 130 serum samples (from 31 patients with post-streptococcal glomerulonephritis, 26 patients with group A streptococcal pharyngitis, 5 patients with scarlet fever, 29 patients with non-group A streptococcal pharyngitis, 20 healthy children, and 19 healthy adults). The results were compared with those obtained simultaneously by two conventional methods, the Rantz-Randall and the NA-Latex-ASL methods. The results obtained by the Toraysphere method showed an excellent correlation with those obtained by each conventional method (correlation coefficients, 0.932 for the Rantz-Randall method and 0.913 for the NA-Latex-ASL method). The performance of each method was evaluated with respect to the clinical and microbiological diagnoses for each patient. The sensitivity, specificity, positive predictive value, and negative predictive value for the Toraysphere method were 76, 84, 81, and 79%, respectively. The corresponding values for the Rantz-Randall method were 48, 78, 67, and 62%, respectively, while those for the NA-Latex-ASL method were 60, 82, 76, and 69%, respectively. Because the Toraysphere method is simple and reproducible, has a short reaction time, and has a clear-cut endpoint for the analysis, we recommend it for routine use in determining the ASO titer in the clinical microbiology laboratory.

Clinical behavior of borderline ovarian tumors: a study of 150 cases

BACKGROUND

We evaluated the clinical features, treatment, and survival status of the patients with borderline ovarian tumors.

METHODS

A retrospective review of the charts of 150 patients with borderline ovarian tumor registered at the Tokai Ovarian Tumor Study Group from January 1, 1980, to December 31, 1994, was conducted to obtain clinical and pathological information.

RESULTS

In stage II and III disease, the numbers of patients with no residual tumor, residual tumor of <2 cm, 2-5 cm, and >5 cm were 9, 10, 3, and 3, respectively. The sizes of residual tumors and corresponding clinical response to chemotherapy were as follows: residual tumor of <2 cm, complete response (CR), 6 patients; no change (NC), 2; progressive disease (PD), 2; tumors 2-5 cm, NC, 1 patient, PD, 2; tumors >5 cm, PD, 3 patients. The survival for patients with residual tumor <2 cm was significantly better than for those with residual tumor from 2-5 cm and of >5 cm (P < 0.05). The survival for patients with stage II and III serous tumor was significantly longer than that for patients with stage II and III mucinous tumor (P < 0.05).

CONCLUSION

In advanced borderline ovarian tumor, the prognosis of patients with gross residual tumor after initial surgery, and especially with mucinous tumor, was poor.