Minisatellite instability in severe combined immunodeficiency mouse cells

We have recently found that okadaic acid, which shows strong inhibitory activity on protein serine/threonine phosphatases and tumor-promoting activity in vivo and in vitro, induces minisatellite mutation (MSM). Human tumors and chemically induced counterparts in experimental animals are also sometimes associated with MSM. In the present study, we demonstrated minisatellite (MS) instability in severe combined immunodeficiency (SCID) cells in which the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is impaired. Cells from a SCID fibroblast cell line transformed by simian virus 40 large tumor antigen, SC3VA2, and from an embryonal SCID fibroblast cell line, SC1K, were cloned and propagated to 10(7) to 10(8) cells, and then subjected to subcloning. After propagation of each subclone to 10(7) to 10(8) cells, DNA samples were digested with HinfI and analyzed by Southern blotting using the Pc-1 MS sequence as a probe. Under low-stringency conditions, about 40 MS bands were detected, with 45% +/- 6% and 37% +/- 3% of SC3VA2 and SC1K cells, respectively, having MSM. In contrast, cells from the RD13B2 cell line, which was established from SCVA2 by introducing human chromosome 8q fragments, on which DNA-PKcs is known to reside, to complement the SCID phenotype, showed a very low frequency of MSM (3% +/- 3%). The high frequencies of MSM in SC3VA2 and SC1K were significant, with no difference between the two. The present study clearly demonstrates that MS instability exists in SCID fibroblasts, suggesting that DNA-PKcs might be involved in the stable maintenance of MS sequences in the genome.

Biomechanical and morphological studies on the periodontal ligament of the rat molar after treatment with alpha-amylase in vitro

Biomechanical properties and morphological features of the rat molar periodontal ligament were examined after treatment with alpha-amylase. Treatment with alpha-amylase induced dose-dependent decreases in the maximum shear stress, tangent modulus, and failure strain-energy density of the periodontal ligament; in addition, it weakened the alcian-blue staining of the periodontal ligament and exposed periodontal collagen fibrils as revealed by scanning electron microscopy. Azan staining and polarized microscopic observations of the periodontal collagen fibers were not markedly different between the control and alpha-amylase treated specimens. These results suggest that decreases in the strength of the periodontal ligament due to alpha-amylase digestion are largely due to removal of interfibrillar substances such as acid glycosaminoglycans and neutral polysaccharides from the periodontal ligament. It is also suggested that the interaction of the interfibrillar substances with collagen fibrils is involved the biomechanical properties of the periodontal ligament.

Application of PCR-RFLP and MASA analyses on 18S ribosomal RNA gene sequence for the identification of three Ginseng drugs

In order to develop convenient and reproducible methods for the identification of Ginseng drugs at a DNA level, PCR-Restriction fragment length polymorphism (PCR-RFLP) and Mutant allele specific amplification (MASA) analyses were applied, based on differences of the 18S rRNA gene sequence among three Panax species. The PCR product of each species on the 18S rRNA gene was digested with the restriction enzymes Ban II and Dde I. Each fragment gave unique electrophoretic profiles for each species (PCR-RFLP analysis). The extracted DNA of each species was amplified by PCR using a designed species-specific oligonucleotide primer. The expected size of the fragments corresponding to each species were detected only when the optimum temperature and reaction time for annealing and extension were established (MASA analysis). These two analytical methods were carried out on three Ginseng drugs and the same results as in their original plants were obtained. The results suggest that PCR-RFLP and MASA analyses under the established conditions are convenient for identifying three Ginseng drugs. Moreover, to insure completion of the identification, a partial sequence of the plastid gene matK was determined in addition to the 18S rRNA gene. The gene sequences of three Panax species were of 1259 base pairs and that of P. quinquefolius was different from the other two at nucleotide position 102.

Heterologous protein production in Acremonium chrysogenum: expression of bacterial cephalosporin C acylase and human thrombomodulin genes

We have developed an efficient expression system for foreign genes in Acremonium chrysogenum. After inserting the foreign gene between the phosphoglycerate kinase (PGK) promoter and a terminator derived from A. chrysogenum, multiple copies of this expression unit are tandemly ligated into cosmids and the resultant cosmids are introduced into A. chrysogenum. We expressed Pseudomonas cephalosporin C acylase and a human thrombomodulin mutant protein containing the fourth, fifth, and sixth epidermal growth factor (EGF)-like structures (E456). The acylase activity in the transformants obtained using our system was several times higher than that in the transformants without the use of the system. The acylase proteins expressed had enzymatic and immunochemical properties identical to those of authentic acylase. The transformants with the expression plasmid for E456 secreted biologically active E456 protein into the culture medium. The amino terminal sequence of the purified E456 was identical to that of recombinant E456 obtained using mammalian cells.

Genetic mapping using microcell-mediated chromosome transfer suggests a locus for Nijmegen breakage syndrome at chromosome 8q21-24

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder characterized by microcephaly, short stature, immunodeficiency, and a high incidence of cancer. Cultured cells from NBS show chromosome instability, an increased sensitivity to radiation-induced cell killing, and an abnormal cell-cycle regulation after irradiation. Hitherto, patients with NBS have been divided into the two complementation groups V1 and V2, on the basis of restoration of radioresistant DNA synthesis, suggesting that each group arises from a different gene. However, the presence of genetic heterogeneity in NBS has been considered to be controversial. To localize the NBS gene, we have performed functional complementation assays using somatic cell fusion between NBS-V1 and NBS-V2 cells, on the basis of hyper-radiosensitivity, and then have performed a genomewide search for the NBS locus, using microcell-mediated chromosome transfer followed by complementation assays based on radiosensitivity. We found that radiation resistance was not restored in the fused NBS-V1 and NBS-V2 cells and that only human chromosome 8 complements the sensitivity to ionizing radiation, in NBS cell lines. In complementation assays performed after the transfer of a reduced chromosome, merely the long arm of chromosome 8 was sufficient for restoring the defect. Our results strongly suggest that NBS is a homogeneous disorder and that the gene for NBS is located at 8q21-24.

An international outbreak of Salmonella infections caused by alfalfa sprouts grown from contaminated seeds

An outbreak of Salmonella serotype stanley infections occurred in the United States and Finland in 1995. The outbreak was investigated through case-control studies in Arizona, Michigan, and Finland; by isolate subtyping; and by tracing and culturing of the implicated food. Alfalfa sprout consumption was the only exposure associated with S. stanley infections in Arizona (matched odds ratio [MOR] = 11.1; 95% confidence interval [CI], 1.4-513), Michigan (MOR = 5.5; CI, 1.6-23), and Finland (MOR undefined; CI, 4.9-infinity). US and Finnish patient isolates were a unique outbreak strain distinct from S. stanley isolates not linked to the outbreak. Alfalfa sprouts eaten by patients in 6 US states and Finland were traced to seed shipped by a Dutch shipper. Thus, it was concluded that alfalfa sprouts grown from contaminated seed caused an international outbreak of > or =242 S. stanley infections in > or =17 US states and Finland. This outbreak illustrates a new mechanism through which contamination of fresh produce can cause large, widely dispersed outbreaks.

[Successful treatment of intraoperative myocardial ischemia with nicorandil]

We report five patients who developed intraoperative myocardial ischemia but were treated successfully with nicorandil. Case 1; An 84 year-old male underwent emergent laparotomy and ileolysis under inhalational plus thoracic epidural anesthesia. During his emergence from anesthesia, arterial pressure and heart rate increased abruptly due to excitement, leading to ST-T depression on V5 lead. Bradycardia and hypotension developed subsequently. Immediately after i.v. injections of nicorandil 4 mg and atropine 0.3 mg, ST-T change and hemodynamics improved dramatically. Case 2; A 67 year-old male underwent esophagectomy under inhalational plus thoracic epidural anesthesia. Following the completion of surgery, elevation of ST-T developed suddenly on lead II, though hemodynamics were not compromised. ST-T elevation disappeared immediately after nicorandil 6 mg and continuous infusion of nitroglycerin (TNG) was initiated. Case 3; A 71 year-old female underwent aortic valve replacement under high-dose fentanyl anesthesia. Shortly after starting cardiopulmonary bypass (CPB), ST-T segment on leads II and V5 was elevated suddenly. This was accompanied by severe pulmonary hypertension suggestive of severe left ventricular failure. Shortly after nicorandil 4 mg via a pulmonary artery (PA) catheter, ST-T segment returned to the baseline and pulmonary arterial pressure was normalized. Case 4; A 61 year-old male underwent coronary revascularization under high-dose fentanyl anesthesia. During weaning from CPB, elevation of ST-T segment occurred on leads II and V5. ST change improved, responding to nicorandil 6 mg en bolus via a PA catheter. Case 5; A 67 year-old male underwent coronary revascularization under high-dose fentanyl anesthesia. He was unable to be weaned from CPB for several hours because of frequent and repeated attacks of ventricular tachycardia and ventricular fibrillation. The arrhythmia did not respond to various kinds of treatments including intra-aortic balloon pumping and continuous infusions of inotropes, anti-arrhythmic drugs and anti-anginal drugs. In spite of repeated intracoronary injections of TNG, graft flow to the left anterior descending branch remained low at 40 ml.min-1. After an intracoronary injection of nicorandil 1 mg, however, blood flow increased to 100 ml.min-1, resulting in a marked reduction in frequency of ventricular arrhythmia. The patient came off bypass successfully. In each case, intraoperative myocardial ischemia was treated successfully with nicorandil. Neither hypotension nor arrhythmia resulted from its bolus injection. Nicorandil might be a useful therapeutic tool for myocardial ischemia during anesthesia.

[Atypical lung abscess occurring in an elderly female suffering from diabetes mellitus--a case report]

We report an atypical case of lung abscess occurring in a 73-year-old female who suffered from diabetes for more than 20 years. In 1993 she had a total gasterectomy for gastric cancer. In 1995 she was admitted to our hospital complaining of a mild cough and a small amount of sputa. A CT scan of the chest revealed a huge abscess in the left lung. Streptococcus sanguis was cultured from the intrathoracic fluid. It is possible that the severe lung abscess in spite of the few symptoms occurs in the compromised host, such as this patient who suffered from diabetes for long time. Oral streptococci in close relationship to misswallowing should be taken into consideration as one of the causes of this condition.

Inhibitory action of (-)-epigallocatechin gallate on radiation-induced mouse oncogenic transformation

The anticarcinogenic activity of a major component of green tea, (-) epigallocatechin gallate (EGCg) was examined by using the radiation-induced oncogenic transformation in C3H10T1/2 cells. EGCg substantially suppressed the radiation-induced transformation so that the transformation frequency with 15 microM of EGCg was reduced nearly to spontaneous levels. This effect of EGCg was in a dose-dependent manner and significant suppression of transformation was observed even in treatment of cells with 5 microM of EGCg concentration where the cytotoxicity was mild. The inhibitory effect of EGCg was maximal when it was present during the entire incubation period. However, neither treatment prior to nor concurrent with radiation was effective, suggesting that EGCg action is mainly involved in the promotional stage of C3H10T1/2 cell transformation.

Uninephrectomy prevents the ischemia-induced increase in renin activity

Contralateral uninephrectomy attenuates unilateral ischemic injury. The present work was performed to elucidate whether the beneficial effect of uninephrectomy was associated with the modification of ischemia-induced changes in plasma or renal renin activity. A 60-min left renal artery occlusion was conducted in right nephrectomized (Nx) and sham-nephrectomized (Sham-Nx) rats. The decline in inulin clearance 48 h after ischemia was significantly less in Nx rats than in Sham-Nx animals (0.50 +/- 0.10 vs. 0.052 +/- 0.029 ml/min/kidney, p < 0.05). Following ischemia, plasma renin activity (PRA) significantly increased in Sham-Nx (from 5.4 +/- 0.9 to 15.5 +/- 1.4 ng AI/ml/min, p < 0.01) but not in Nx (from 3.5 +/- 0.5 to 5.0 +/- 1.0 ng AI/ml/ min) animals. PRA and renal cortical renin content (2,200 +/- 225 vs. 1,257 +/- 187 ng AI/h/mg protein, p < 0.05) were significantly less in Nx rats than in Sham-Nx animals 48 h after renal ischemia. The decrease in body weight was greater in Nx rats than in Sham-Nx animals. Plasma atrial natriuretic peptide (ANP) (195 +/- 30 vs. 302 +/- 40 pg/ml, p < 0.05) and renal dopamine (DA) content (3.2 +/- 0.5 vs. 13.7 +/- 1.3 ng/g tissue, p < 0.01) were rather lower in the Nx group when compared with the Sham-Nx group. No significant difference was found in the intrarenal content of norepinephrine (NE) between two ischemic groups. These findings suggested that uninephrectomy prevents the ischemia-induced increase in renin activity. The prevention of the increase in renin activity in Nx rats is not be mediated through the modulation of ischemia-induced changes in sodium balance, plasma ANP level and/or intrarenal contents of NE and DA.

Differential regulation of gap junction protein (connexin) genes during cardiomyocytic differentiation of mouse embryonic stem cells in vitro

Using an in vitro system for differentiation of embryonic stem (ES) cells into cardiac myocytes, we analyzed the expression of connexin (Cx) genes by RT-PCR to learn what changes in the expression of multiple connexin genes occur during the early stage of heart development. We also examined gap junctional intercellular communication by using Lucifer Yellow dye microinjection transfer, studied intracellular Ca2+ transients by confocal laser image analysis using fluo 3, and determined localization of Cx43 by immunofluorescence during in vitro differentiation of ES cells into cardiac myocytes. The transcripts for Cx43 and Cx45 were detected in undifferentiated ES cells and in embryoid bodies before and after the appearance of beating cardiomyocytes. In contrast, Cx40 transcripts were not observed in undifferentiated ES cells and were barely detectable in 3- and 5-day-old embryoid bodies. Cx40 transcripts significantly increased with the appearance of beating cells similar to those of cardiac-specific genes. Dye coupling was present among undifferentiated ES cells, prebeating cells of embryoid body outgrowth and ES cell-derived beating cardiomyocytes. When dye was injected into a beating cell, dye spread was restricted to neighboring beating cells. Immunofluorescence demonstrated that Cx43 protein was localized not only in beating cells but also in surrounding nonbeating cells, whereas myosin heavy chain alpha/beta was exclusively positive in the beating cells. These data suggest that the expression of multiple connexins is differentially regulated during the cardiomyocytic differentiation of ES cells in vitro and that Cx40 expression may be linked to early stages in cardiomyocytic differentiation.

A novel stilbene glucoside, oxyresveratrol 3'-O-beta-glucopyranoside, from the root bark of Morus alba

A novel stilbene glucoside was isolated from the root bark of Morus alba L. (Moraceae), along with mulberroside A, cis-mulberroside A, oxyresveratrol. The structure of the novel stilbene glucoside was determined as oxyresveratrol 3'-O-beta-glucopyranoside.

The scid mutation does not affect slowly repairing potentially lethal damage that is sensitive to 0.23 M NaCl

The repair of slowly repairing potentially lethal damage (PLD) in radiosensitive cells from the severe combined immunodeficient (scid) mouse was compared with that in Balb/c 3T3 cells with "wild-type" radiosensitivity and that in RD13B2 cells derived from scid cells whose sensitivity is normal because of the presence of fragments of human chromosome 8. Treatment with 0.23 M NaCl was used for fixation of slowly repairing PLD. The scid cells repaired PLD sensitive to 0.23 M NaCl to a great extent whin 3-4 h, similarly to Balb/c 3T3 and RD13B2 cells. This indicates that the scid mutation hardly affects the repair of PLD sensitive to 0.23 M NaCl. On the other hand, as reported previously, the rapidly repairing PLD that is sensitive to 0.5 M NaCl was repaired only slowly (3-4 h) in scid cells, in contrast to the rapid repair (within 1 h) seen with Balb/c 3T3 and RD13B2. This suggests that scid mutation is responsible for this repair at reduced rate. To confirm the independence of repair of 0.23 M NaCl-sensitive PLD from that of 0.5 M NaCl-sensitive PLD, both treatments with 0.23 M NaCl and 0.5 M NaCl were combined in each line. It is found that the repair of either PLD was not affected by the other treatment. The scid mutation impaired only the repair of 0.5 M NaCl-sensitive PLD.

[Botanical origin of commercial samples of traditional Chinese drug xixin (Herba Aasari)]

It has been found out that amony the 158 samples of commercial drug. Xixin (Herba Asari) collected from 28 provinces/cities of China, only three guarters are derived from the species specified in the Chinese Pharmacopoeia and the rest are not. One hundred and eleven samples are derived from Asarum heterotropoides var. mandshuricum and are presently used in 26 provinces/cities, 25 samples are derived from A. himalaicum and used in 10 provinces, the other 22 samples are derived from 9 species such as A. sieboldii, A. forbesii, etc.

Pharmacological properties of traditional medicines. XXII. Pharmacokinetic study of mulberroside A and its metabolites in rat

To identify the active components in Mori Cortex (Chinese medicine), Mori Cortex extracts were administered orally to rats, and then blood plasma, urine, and bile were analyzed. The results showed only a few remaining metabolites of mulberroside A. Consequently, to clarify the transitional properties of mulberroside A derivatives to tissues and the in vivo abundance ratio of mulberroside A compounds, the pharmacokinetics of mulberroside A derivatives were investigated in this study. When Mori Cortex extracts were administered orally, mulberroside A was only detected in small quantities in the plasma, and its bioavailability was about 1%. This is due to the first pass effect, by which most mulberroside A was converted into oxyresveratrol and transported into the circulating blood, and its absorption ratio was estimated at about 50%. Oxyresveratrol was found to be transported to tissues at high rates. As a result, when analyzing the pharmacological activity of the Mori Cortex in vitro, it is more useful to study oxyresveratrol than mulberroside A.

18S ribosomal RNA gene sequences of three Panax species and the corresponding ginseng drugs

Total DNA was extracted from the fresh underground parts of three Panax separate species. The 18S rRNA regions of extracted DNA were amplified by the polymerase chain reaction (PCR) and their sequences were determined. In each species, the sequences were found to be of 1809 base pairs (bps) but with different gene sequences. Different base substitutions were observed at nucleotide positions 497, 499, 501 and 712. The same procedure was performed on commercial samples of Ginseng Radix, Panacis Japonici Rhizoma and American Ginseng. Each sequence completely corresponded with that of each original plant, namely P. ginseng, P. japonicus and P. quinquefolius, respectively. This is the first time that 18S rRNA gene sequencing on Panax species was carried out. Previously, Ginseng drugs have been identified mainly by their external and internal structure. Thus this method will be useful in identifying Ginseng drugs at the gene level.

Prediction of adult height in healthy Japanese children

Longitudinal records from 13,707 children (6749 boys and 6958 girls), aged 6-17 years, were fitted by a smoothing cubic spline function, and the factors influencing changes in height SD score (SDS) during puberty were analysed. Height SDS at 6 years correlated closely with final height SDS. However, short children at 6 years of age tended to increase their height SDS at final height, whereas tall children at the same age tended to decrease their final height SDS for children with the same prepubertal height, the later that pubertal maturation occurred, the greater was the final height achieved. As short children entered puberty relatively late and tall children entered puberty relatively early, height SDS tended to approach 0 SD during puberty. A prediction function obtained by multiple regression analysis using height SDS at 6 years, the percentage by which the child is overweight at 6 years, age at onset of the pubertal growth spurt (PGS) and height at onset of the PGS provides a reasonable model for the prediction of final height SDS without the need to estimate bone age.

Addition of purified prostate specific antigen to serum from female subjects: studies on the relative inhibition by alpha 2-macroglobulin and alpha 1-antichymotrypsin

PURPOSE

Two forms of prostate specific antigen (PSA), 1 complexed to alpha 1-antichymotrypsin and the other a free PSA, are recognized by current commercially available immunoassays. A third form of PSA complexed to alpha 2-macroglobulin also is present in the serum. To study these 3 different molecular forms of PSA in vivo, we simulated leakage of PSA from the prostate into the serum in vitro.

MATERIALS AND METHODS

Purified seminal fluid PSA was incubated with fresh sera from female subjects at different concentrations. Following gel filtration chromatography, the 3 forms of PSA were studied by immunoassays and Western blot analysis.

RESULTS

Using a commercial immunoassay, 60% of immunoreactivity of seminal fluid PSA was lost after incubation with sera from female subjects. Western blot analysis showed that most of this loss in PSA signal was caused by complexation to alpha 2-macroglobulin. Minimal, if any, complexation to alpha 1-antichymotrypsin occurred even when excess alpha 1-antichymotrypsin was added to the serum.

CONCLUSIONS

Our studies demonstrated that alpha 2-macroglobulin is a much stronger inhibitor to PSA than alpha 1-antichymotrypsin. Further studies of these complexes may be important. They clearly explain why spiking PSA into sera from female subjects to be used as quality controls for PSA assays leads only to the free form of enzymatically inactive PSA in the serum, and not to the dominant form of complexed PSA and alpha 1-antichymotrypsin present in human serum.

High level of tritium-remaining in brain of rats exposed to tritiated water as infants

Newborn CD/Crj rats were given tritiated water (HTO) saline i.p. at the dose of 220 microCi (8.14 MBq)/g of B.W. We monitored residual tritium in the sera and organs of male rats up to 26 weeks of age. The total absorbed doses in serum, liver, spleen, testis and brain were estimated to be 3.10, 2.35, 2.43, 2.38 and 2.84 Gy, respectively. Over four weeks of age, a 3-19 times higher tritium content was noted in brain compared to the values of other organs. At 26 weeks of age, testis atrophy was predominant with 20% of control value by relative organ weight in association with decreased spermatogonia and increased Leydig cells. The serum testosterone level was 67% and relative adrenal weight was significantly increased in comparison with the control values. The results indicated that the high accumulation of tritium in brain, destruction of spermatogenesis and feedback of androgenic response were caused by exposure to HTO as infants.

Keio multicenter trial in high-dose interferon-alpha 2b treatment for chronic hepatitis C. Keio Interferon-alpha 2b Study Group

The efficacy of two different high-dose treatment of IFN-alpha 2b was evaluated in this study. Serum hepatitis C virus (HCV) RNA levels were semi-quantified by simplified reverse transcription-polymerase chain reaction. Seventy-one patients with chronic hepatitis C received 10 million units of IFN-alpha 2b daily for 2 weeks or twice a week for 24 weeks. Alanine aminotransferase (ALT) levels overall normalized in 78.1% and 51.6% of the cases at the end of the therapy and 6 months after that, respectively. HCV RNA disappeared in 71.9% and 35.7% of the patients at the end of the therapy and 6 months after that, respectively. There was no significant difference between the 2 different regimes. The efficacy of the treatment was fair in cases in which the pretreatment level of the viral amount was low. The results of this study indicate that daily administration of IFN in the first 2 weeks during 6-month course does not increase the efficacy of the therapy in such a high-dose treatment regime.

[Maze operation for chronic atrial fibrillation with valvular heart diseases]

Between July 1994 and August 1995, 14 patients underwent combined modified maze procedure and valvular surgery including 5 patients having reoperation. Associated procedures were performed with mitral valve operation (n = 13), tricuspid annuloplasty or valve replacement (n = 9) and aortic valve replacement (n = 4). Duration of atrial fibrillation (AF) varied from 1 to 18 years (mean 8.0 +/- 5.8 year), the f-wave voltage ranged from 0.05 to 0.5 mV (0.21 +/- 0.13 mV), left atrial dimension (LAD) ranged from 35.6 to 66.3 mm (49.0 +/- 9.3). One patient died 2 months after undergoing combined maze procedure and MVR + TAP due to pulmonary infection and sepsis, but the other 13 patients survived. Nine patients (69%) regained atrial rhythm, two patients (15%) had junctional rhythm and another two (15%) remained in AF at follow-up periods between 1 to 11.5 months (6.3 +/- 3.1). The nine patients who recovered to normal sinus rhythm had preoperative f-wave for a significant higher voltage than the patients with AF and JR (0.27 +/- 0.12 vs 0.13 +/- 0.05 mV, p < 0.05) and a smaller left atrial dimension (44.5 +/- 0.7 vs 54.8 +/- 6.9 mm, p < 0.05). These data suggest that the maze operation is effective and should be considered for patients with chronic AF indicated for surgical valvular diseases.