[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1998 and March 1999]

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. This paper describes the results obtained in fiscal 1998 (from April 1998 to March 1999). The number of cases investigated as objectives was 225 for one year. A total of 429 strains (121 strains from primary infections and 308 strains from postoperative infections) were isolated from 183 cases (81.3% of total cases). In primary infections, the isolation rates of anaerobes and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes and Pseudomonas aeruginosa were higher than in primary infections. On the whole, among Gram-positive aerobes, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus with high frequency in isolation from postoperative infections. Among Gram-positive anaerobes, Peptostreptococcus spp. and Streptococcus spp. were predominantly isolated. Among Gram-negative aerobes, E. coli, P. aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae were frequently isolated. Among Gram-negative anaerobes, Bacteroides fragilis group was the majority of isolates. In primary infections, the percentage of Gram-negative aerobes has gradually increased since fiscal 1995 or 1996 with these years as the turning point, while those of Gram-positive and Gram-negative anaerobes have gradually declined. In postoperative infections, the percentage of Gram-negative anaerobes has increased continuously since the mid-1980s. The percentage of MRSA among S. aureus rose to 89.7%, which was the highest level since the beginning of this study. The susceptibilities of B. fragilis, which did not show apparent changes, were recognized to have decreased against cephems in fiscal 1998. Among other bacteria in B. fragilis group, development of resistance to cephems has continued on a long-term basis since the mid-1980s. E. coli and K. pneuminiae have obviously not changed in susceptibilities, however, the susceptibilities of isolated strains in fiscal 1998 against high-generation cephems, oxacephems and monobactams have declined. We found neither vancomycin-resistant nor teicoplanin-resistant strains of S. aureus and Enterococcus spp.

Kupffer cell function in ischemic and nonischemic livers after hepatic partial ischemia/reperfusion

Hepatic partial ischemic/reperfusion (I/R) injury, in which ischemic and nonischemic areas of the liver are likely to respond to each other after reperfusion, often occurs following hepatobiliary surgical procedures. Kupffer cells (KCs) are considered to play a major role in hepatic I/R injury. To study the activation of KCs in ischemic and nonischemic liver tissues following hepatic I/R, we investigated the superoxide generation and proinflammatory cytokine production of KCs in both liver parts in a rat model of partial hepatic I/R injury. KC superoxide generation in the ischemic and nonischemic lobes was upregulated 6 and 24 h after reperfusion, respectively, and then accelerated. The production of interleukin-1beta (IL-1beta) by KCs in the ischemic lobes increased during the early and late phases, 6 h and 48-72 h after reperfusion, respectively. A late increase in IL-1beta production was also observed in the nonischemic lobes. Production of tumor necrosis factor-alpha (TNF-alpha) increased 6-24h after reperfusion in both lobes. Upregulation of IL-1beta mRNA in the ischemic lobes preceded the upregulation of TNF-alpha mRNA in both lobes. The hepatic partial I/R process results in activation of KCs in ischemic and nonischemic areas of the liver. The KCs are activated during the early phase after reperfusion in the ischemic areas, followed by activation in both the ischemic and nonischemic areas. This could be a cause of liver dysfunction after partial hepatic I/R during surgery.

Telomerase and cancer

Telomerase, a eukaryotic ribonucleoprotein (RNP) complex, contains both an essential RNA and a protein reverse transcriptase subunit. By reverse transcription, the telomerase RNP maintains telomere length stability in almost all cancer cells. Over the past few years there has been significant progress in identifying the components of the telomerase holoenzyme complex and the proteins that associate with telomeres, in order to elucidate mechanisms of telomere length regulation. This review covers recent advances in the field including the use of telomerase in cancer diagnostics and an overview of anti-telomerase cancer therapeutic approaches.

Frequent deletions and mutations of the beta-catenin gene are associated with overexpression of cyclin D1 and fibronectin and poorly differentiated histology in childhood hepatoblastoma

Hepatoblastoma (HBL) is the most common malignant liver tumor in young children. Recent reports have shown that the beta-catenin gene was frequently mutated or deleted in HBLS: To elucidate the role of beta-catenin abnormalities in HBLs, we searched for mutations of beta-catenin and APC as well as expression of the target genes, cyclin D1, c-myc, and fibronectin, in 68 primary HBLS: The mutation analysis revealed that 44 (65%) tumors carried missense mutations or deletions of beta-catenin, all of which were somatic and targeted to the exon 3 encoding the amino acid residues involved in its degradation. However, no loss of function mutation of the APC gene was detected by the yeast functional assay. Of interest, beta-catenin mutation was significantly correlated with overexpression of the target genes, cyclin D1 and fibronectin, but not with that of c-myc in HBLs as measured by quantitative real-time reverse transcription-PCR. The immunohistochemical studies in 15 HBLs demonstrated that the nuclear/cytoplasmic accumulation of beta-catenin was positive in 13 tumors, 9 of which had the deletion or mutation of the gene. The significant correlation between the beta-catenin gene abnormality and the positive staining of cyclin D1 was also confirmed. Furthermore, the nuclear accumulation of beta-catenin was strongly associated with the poorly differentiated tumor cell components as well as with the positive staining of cyclin D1 within the tumor. Thus, our present results suggested that the gain of function mutation of beta-catenin played a crucial role in the malignant progression of HBL in vivo.

Progression of primary biliary cirrhosis after proctocolectomy for ulcerative colitis

We report a case of progression of primary biliary cirrhosis (PBC) after proctocolectomy for ulcerative colitis. A 43-year-old woman underwent a total proctocolectomy after being diagnosed with ulcerative colitis. In the course of the preoperative investigation, liver function test results were within the normal range. Four months after the proctocolectomy, the patient showed a high level of alkaline phosphatase (2398 IU/l) and a positive anti-mitochondrial antibody titer (>1:160). There were no associated symptoms. A liver biopsy demonstrated expansion of all portal areas by infiltrates of lymphocytes and histiocytes. These appearances indicated chronic biliary disease and were compatible with PBC. The association of PBC and ulcerative colitis is rare. However, a review of the recent literature suggests that PBC and ulcerative colitis may be associated; this combination should be kept in mind.

Biological characteristics of neuroblastoma with partial deletion in the short arm of chromosome 1

BACKGROUND

Neuroblastoma shows remarkable heterogeneity, resulting in favorable and unfavorable outcomes. It is well known that almost all cases with MYCN amplification have a poor prognosis. We have previously reported that unfavorable tumors show high telomerase activity, whereas favorable tumors show low or nil activity. We also found that the unfavorable neuroblastoma often have a loss of heterozygosity (LOH) at the MYCL locus.

PROCEDURE

To clarify the biological and clinical profiles of tumors with genetic abnormalities of the short arm of chromosome 1, we performed deletion mapping on 1p on 92 neuroblastoma tissues and corresponding noncancerous samples obtained from 92 cases for 24 micro- or minisatellite loci.

RESULTS

LOH was detected in at least one locus of 1p in 43 (47%) cases. All samples were classified into four groups according to the deleted pattern: interstitial deletion (group I, n = 20), short terminal deletion (group ST, n = 6), large terminal deletion (group LT, n = 17), and without detectable deletion (group N, n = 49). All group I cases, whose SRO (shortest region of overlap) was at 1p36.1-2, survived disease free, and none of them showed MYCN amplification or high telomerase activity except for one case. On the other hand, in group LT cases, who showed a large terminal deletion from D1S162 (1p32-pter), including the SRO of group 1, only 5 out of 17 have survived disease free, and 13 showed MYCN amplification or high telomerase activity. The six group ST cases showed small terminal deletion from 1p36.3 with modest prognosis, similar to the group N.

CONCLUSIONS

Thus, we propose three loci, 1p36.1-2, 1p32-34, and 1p36.3, as the candidate loci of neuroblastoma suppressor genes on chromosome 1p responsible for groups I, LT, and ST, respectively. Among them, the 1p32-34 locus may be associated with aggressiveness of tumor progression, possibly due to MYCN amplification and/or telomerase reactivation, while the remaining two loci may not.

Telomerase activity as a marker of breast carcinoma in fine-needle aspirated samples

BACKGROUND

Telomerase activity in breast fine-needle aspiration (FNA) samples may have diagnostic utility. The purpose of this study was to compare in FNA samples of breast tumor the diagnostic accuracy as correlated with histologic final diagnosis.

METHODS

Fine-needle aspiration samples were obtained from 617 patients with palpable breast tumors. Slide preparation and cytology were performed according to a uniform approach. Extracts derived from 10(3) cells from the residual cells in the syringe were used for the telomeric repeat amplification protocol (TRAP) assay. Of the original 617 patients, 220 underwent open biopsy or surgery, and 93 cancers and 127 patients' benign diseases were diagnosed by histologic examination.

RESULTS

All 62 tumors that were diagnosed as "malignant" or "probably malignant" by FNA cytology were cancerous, and 50 cases (81%) showed detectable telomerase activity. Among 17 "atypical" or "indeterminate" cases, all 10 tumors with detectable telomerase activity subsequently were diagnosed as breast carcinoma whereas 6 of 7 tumors without telomerase activity were diagnosed as benign. Among the 141 "benign" or "unsatisfactory" samples, 12 of 21 cases with detectable telomerase activity subsequently were diagnosed as cancer.

CONCLUSIONS

The diagnostic accuracy of telomerase activity in FNA samples is considered to be equivalent or slightly higher to that of cytology (86% vs. 70%). Detection of telomerase activity should be considered an alert for false-negative results of FNA cytology and may be useful as a diagnostic marker for breast malignancy, especially in samples cytologically undetermined to be malignant. Cancer (Cancer Cytopathol)

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1997 and March 1998]

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 19 facilities in Japan since July 1982. This paper describes the results obtained during the period from April 1997 to March 1998. The number of cases investigated as objectives was 215 for one year. A total of 420 strains (170 strains from primary infections and 250 strains from postoperative infections) were isolated from 174 cases (80.9% of total cases). In primary infections, the isolation rate of anaerobic bacteria was higher than in postoperative infections, while in postoperative infections, those of aerobic Gram-positive bacteria and Pseudomonas aeruginosa were higher than in primary infections. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus, which was frequently isolated from postoperative infections. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by P. aeruginosa, Klebsiella pneumoniae in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. coli and K. pneumoniae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. We found neither vancomycin nor arbekacin resistant strains of S. aureus, and found no vancomycin resistant strains of Enterococcus spp. The susceptibility of P. aeruginosa against carbapenems did not decline in the year 1997, while resistance of B. fragilis group against cephems advanced increasingly.

LambdaN spin-orbit splittings in (9)(Lambda)Be and (13)(Lambda)C studied with one-boson-exchange LambdaN interactions

Movitated by the on-going gamma-ray experiments at the Alternating Gradient Synchrotron at Brookhaven National Laboratory, we discuss the energy splittings of the 5/2(+)(1)-3/2(+)(1) doublet in (9)(Lambda)Be and the 3/2(-)(1)-1/2(-)(1) doublet in (13)(Lambda)C for which the LambdaN spin-orbit ( LS) and antisymmetric spin-orbit ( ALS) forces are relevant. In the microscopic 2alpha+Lambda ( 3alpha+Lambda) model for (9)(Lambda)Be ( (13)(Lambda)C), all the available Nijmegen one-boson-exchange (OBE) model LambdaN interactions lead to a wide range of splittings of 0.08-0.20 MeV in (9)(Lambda)Be and 0.39-0.96 MeV in (13)(Lambda)C. On the other hand, if we use information from quark-model LambdaN interactions which have generally large ALS force, the splittings become about half of the smallest OBE model prediction.

High telomerase activity is an independent prognostic indicator of poor outcome in colorectal cancer

Telomerase activity and altered telomere length have been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In the present study, we investigated telomerase activity and telomere length in colorectal cancers and noncancerous colonic mucosa specimens in 100 patients between 1991 and 1996. To determine whether the level of telomerase activity or telomere length is a prognostic indicator of patient outcome, we followed these patients more than 3 years after surgery. Among 100 primary colorectal cancer specimens, 96 specimens had telomerase activity. Because noncancerous mucosa has some detectable telomerase activity, we divided the levels of telomerase activity into three categories: high (>50-fold more than that in noncancerous mucosa); moderate (10- to 50-fold); and low (<10-fold) levels. Among 100 cancer tissues, 28 showed moderate telomerase activity and 44 showed high telomerase activity. The frequency of tumors with moderate or high telomerase activity showed no significant relationship with any clinicopathological factors. The prognosis of the patients with high telomerase activity was significantly worse than that for patients with moderate and low telomerase activity (P < 0.01). Among the 87 patients with curative surgery, disease-free survival rate of those with high telomerase activity was also significantly poorer (P < 0.01). These results indicate that a high level of telomerase activity may be an independent prognosis-predicting factor in the patients with colorectal cancer.

Allelotype and loss of heterozygosity around the L-myc gene locus in primary lung cancers

L-myc S-allele was reported to be associated with metastasis of lung cancer, indicating the existence of a putative tumor suppressor gene around the L-myc locus, in linkage disequilibrium. The relationship between the S-allele and inactivation of some tumor suppressor gene should be indicated by allelic loss. Therefore, we examined the association between the L-myc S-allele and loss of heterozygosity at 11 loci around the L-myc locus (1p34.3) in primary lesions or other biological characteristics in lung cancer. No associations between the S-allele and allelic loss around the L-myc locus or other characteristics were found. According to the deletion map, three shortest regions of overlap between D1S230 and D1S76 were identified. While loss of heterozygosity at SRO1, between D1S2797 and MYCL1, showed no relationship with the pathological stage, it was more frequently observed in squamous cell carcinoma than adenocarcinoma (P=0.019), and associated with high telomerase activity (P=0.046), an indicator of cellular immortality. In conclusion, we found three shortest regions of overlap (SROs) from D1S2797 to pter, and a tumor suppressor gene, which might be associated with suppression of lung cancer development but not with L-myc S-allele, may exist in SRO1.

Multifocal neuroblastoma: biologic behavior and surgical aspects

BACKGROUND

Although multifocal neuroblastoma is rare, its incidence has increased because of recent improvements in diagnostic tools and the introduction of mass screening. Among the 106 neuroblastoma cases treated at the authors' hospital between 1984 and 1998, 8 were multifocal neuroblastoma.

METHODS

The authors examined clinicopathologic findings and biologic features, including MYCN amplification, NTRK1 and Ha-ras p21 expression, cellular DNA content, and telomerase activity in these 8 multifocal neuroblastoma cases. Moreover, clinicopathologic findings were investigated with a review of 53 published cases of multiple neuroblastoma in the literature published in English between 1966 and 1999.

RESULTS

Among these eight cases, five were detected by mass screening and three were incidental neuroblastomas. Histologically, all tumors were classified as ganglioneuroma or favorable neuroblastoma except one advanced case. All tumors lacked the MYCN gene amplification and expressed NTRAK1 mRNA and Ha-ras p21 protein. Cellular DNA content showed that half of these tumors were near-triploid, and the proliferative index (%S-phase) of all tumors was less than 25%. High telomerase activity was detected in none of these cases. Four patients underwent multistage operation and five patients with bilateral adrenal neuroblastomas underwent tumor enucleation to preserve adrenal function. Currently, all patients are disease free and none have required corticosteroid replacement therapy. Among the previously reported 53 cases with multifocal neuroblastoma, 25 were incidentally detected, 18 had familiar history, and most patients without other major complications also had extremely good prognoses.

CONCLUSIONS

These findings suggested that most multifocal neuroblastomas have favorable biologic features. Clinically, surgical approaches should be attempted to preserve organ function, especially adrenal function, and minimal invasive surgery should be performed. In cases of thoracoabdominal neuroblastoma, multistage surgery is effective and safe.

Interleukin-10 expression in intestine of Crohn disease

Inflammatory bowel diseases are considered to be related to dysregulation of pro- and anti-inflammatory cytokines in the intestinal wall. We investigated the levels of TNFalpha, IFNgamma, and IL-10 mRNA expression in intestinal tissues resected from the patients with Crohn disease (CD) (n=29), ulcerative colitis (UC) (n=8), and controls (n=8) using reverse transcription-polymerase chain reaction (RT-PCR). In addition, we examined the relationship between the expression of these cytokine mRNA and their clinical conditions using CD activity index (CDAI) and Nutritional Surgical Risk Index (NSRI). Compared with controls, tissues in CD showed high levels of TNFalpha and IFNgamma mRNA expression both in inflamed and non-inflamed tissues, and showed high levels of IL-10 mRNA expression in inflamed tissues. In UC, high levels of IL-10 mRNA expression were detected both in inflamed and non-inflamed UC tissues, while those of TNFalpha and IFNgamma were not. In 80% of CD tissues (n=23), levels of IL-10 and TNFalpha expression were interrelated. While the remaining tissues (n=6) showed low levels of IL-10 expression despite high levels of TNFalpha expression in inflamed CD tissues, and 4 of these 6 patients had high CDAI and low NSRI. Furthermore, in low nutritional CD patients (NSRI <40, n=13), the levels of IL-10 mRNA to inhibit pro-inflammatory cytokines were poorer than in good nutritional patients (NSRI >/=40, n=16). These findings suggest the overexpressions of TNFalpha and IFNgamma in CD, and less producibility of IL-10 against these cytokine might lead to development of severe CD.

An additional dose of cefazolin for intraoperative prophylaxis

We examined the pancreatic tissue concentrations of cefazolin in ten patients undergoing pancreatectomy, and determined the optimal intraoperative time to deliver a repeat dose of cefazolin. An intravenous bolus dose of 1 g cefazolin was administered at the time of skin incision. Peripheral blood, subcutaneous adipose tissue, and peritoneal samples were obtained intraoperatively every hour for 4 h after the antibiotic was first administered, and pancreatic tissue samples were obtained at the time of pancreatectomy. To determine adequate tissue levels of cefazolin, minimum inhibitory concentrations (MIC) were measured for four bacterial species, namely 360 isolates of methicillin-sensitive Staphylococcus aureus (MSSA), 204 isolates of Klebsiella pneumoniae, 314 isolates of Escherichia coli, and 30 isolates of Streptococcus spp. The antibiotic concentrations in adipose tissue and peritoneum 3 h after the administration of cefazolin were lower than the MIC80 for K. pneumoniae, E. coli, and Streptococcus spp. Most pancreatic tissue samples showed antibiotic concentrations greater than the MIC80 for these bacterial species; however, those from four patients complicated by severe chronic pancreatitis, massive intraoperative bleeding, or obesity showed concentrations lower than the MIC80. Thus, we recommend that a second dose of cefazolin be given 3 h after the first administration to maintain adequate levels of antibiotic activity.

Generation of pro-inflammatory and anti-inflammatory cytokines in the gut in zymosan-induced peritonitis

In major systemic inflammation such as severe peritonitis, various pro-inflammatory cytokines, such as TNF-alpha, IL-1 beta and IL-6, play important roles in the development of multiple organ dysfunction syndrome (MODS). The purpose of this study was to investigate the outflow of pro-inflammatory and anti-inflammatory cytokines from the efferent mesenteric lymphatic vessels under peritonitis. Mesenteric lymph samples were collected from adult male rats at 2, 4, 6, 8 and 10 hr after an intraperitoneal injection of zymosan at a dosage of 0.1 mg/g (non-lethal dose) or 0.5 mg/g (lethal dose). Blood samples were obtained at 10 hr after zymosan administration. The amounts of drained TNF-alpha and IL-6 in the lymph peaked at 2-4 hr and 4-8 hr after zymosan administration, respectively. The amounts of drained IL-10 in the lymph gradually increased until 10 hr. The amounts of drained TNF-alpha and IL-10 in the mesenteric lymph were significantly correlated with the dosage of zymosan. In conclusion, under intraperitoneal inflammation, pro-inflammatory cytokines (TNF-alpha and IL-6) increased in the mesenteric lymph and were drained into circulation. IL-10, one of the anti-inflammatory cytokines, also increased in the mesenteric lymph after several hours' delay and its increase was remarkable in several inflammations. These findings suggested that the gut might be one of the pro-inflammatory and anti-inflammatory cytokine-generating organs under peritonitis. The lymph-drained amounts of each cytokine under peritonitis are considered to differ with the time or severity of inflammation, which may cause different conditions in patients due to the imbalance of pro-inflammatory and anti-inflammatory cytokines.

Lack of CD44 variant 6 expression in advanced extrahepatic bile duct/ampullary carcinoma

BACKGROUND

Transmembrane proteins of the CD44 family play roles in cell-cell and cell-matrix interactions, and their aberrant expression has been reported to be associated with the growth and metastasis of various tumors. The authors examined CD44 standard (CD44st) and CD44 variant 6 (CD44v6) expression in extrahepatic bile duct (EHBD)/ampullary carcinoma.

METHODS

In 36 EHBD/ampullary carcinomas, immunohistochemical analyses with monoclonal antibodies against the human CD44st protein or CD44v6 protein were performed by the streptavidin-biotin immunoperoxidase method. The relation between expression of the proteins and lymph node metastases or patient outcome was investigated. To verify the lack of CD44v6 mRNA expression in tumors negative for CD44v6 staining, reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot hybridization were performed.

RESULTS

Immunohistochemical analyses revealed that 13 of 36 carcinomas (36.1%) expressed the CD44v6 protein. Only 2 of 13 CD44v6-expressing primary tumors (15.4%) had regional lymph node metastases, whereas 14 of 23 tumors showing no CD44v6 expression (60.9%) had lymph node metastases (Fisher exact test, P<0.01). Moreover, a lack of CD44v6 expression was correlated significantly with poor prognosis (generalized Wilcoxon test, P<0.05). Eleven of 13 CD44v6 positive tumors showed CD44st expression, which also was correlated with prognosis. RT-PCR and Southern blot hybridization revealed a lack of CD44v6 mRNA expression in the tumors that were negative for CD44v6 staining.

CONCLUSIONS

The results of the current study suggest that a lack of expression of CD44, especially CD44v6, is correlated with lymph node metastases and poor prognosis, and may be a prognostic factor for patients with EHBD/ampullary carcinoma.

Inhibitory effect of telomere-mimic phosphorothioate oligodeoxy nucleotides (S-ODNS) on human tumor cell lines

To clarify the inhibitory effect of telomere-mimic oligonucleotides on human cancer cell lines, we synthesized 18-mers (18T; n = 3), 24-mers (24T; n = 4) and 30-mers (30T; n = 5) of telomere-mimic phosphorothioate oligodeoxy nucleotides [5'-d(TTA GGG)n-3'] and examined their effects on the proliferation of human tumor cells by XTT assay. After 7 days of continuous exposure to 24T and 30T at concentrations ranging from 0.1 to 10 microM, concentration-dependent cell growth inhibition was observed in MCF-7 clone E3, ZR-75-1, MDA-MB 231, Colo 201 and WiDr. All of these cell lines highly expressed telomerase using the telomeric repeat amplification protocol. None of these tumor cell lines were affected by 18T. In MCF-7, ZR-75-1 and Colo 201 cell lines, a more than 50% growth inhibition was obtained by 3 microM of 24T and 30T whereas, in MDA-MB 231 and WiDr cell lines, cell growth inhibition was less than 50%. 30T was more effective than 24T. Estrogen-dependent growth of both MCF-7 and ZR-75-1 was inhibited by 3 microM of 24T and 30T, however, in the absence of estrogen, no growth inhibition was seen. The MCF-10A cell line, which was developed from normal human breast tissue and expressed telomerase only weakly, was inhibited by 10 microM of 18T. In conclusion, these observations indicate that S-ODNs inhibit tumor growth in cell lines expressing telomerase in a concentration-dependent manner and that cell growth inhibition is dependent on the length of S-ODNs. In addition, the short-length S-ODNs may inhibit growth of cells weakly expressing telomerase, but not of cells with high telomerase expression.

Down-regulation of KAI1 messenger RNA expression is not associated with loss of heterozygosity of the KAI1 gene region in lung adenocarcinoma

KAI1, a metastasis suppressor gene of prostate cancer, is located on human chromosome 11p11.2. Down-regulation of KAI1 mRNA during tumor progression and metastasis has been reported for several kinds of cancer, but the mechanism of this down-regulation is not known. In the present study, our aim was to ascertain the relationship between down-regulation of KAI1 mRNA expression and KAI1 gene alterations in lung cancer. Forty-nine cases of adenocarcinoma of the lung were studied by reverse-transcriptase polymerase chain reaction (RT-PCR) assay of KAI1 mRNA and by immunohistochemical detection of KAI1 protein. In addition, markers of the microsatellite loci D11S1344 and D11S1326 were used to investigate loss of heterozygosity (LOH) and replication errors (RERs) of the KAI1 gene region. The RT-PCR assay showed that there was no correlation between KAI1 mRNA expression and either the age of the patients or tumor size. By contrast, KAI1 mRNA expression was significantly correlated with gender (P=0.047), metastasis to the lymph nodes or other organs (P=0.004), the histological grade of the tumor (P=0.036) and the pathological stage (P=0.049). Immunohistochemical staining showed that in one case without metastasis, loss of KAI1 mRNA was associated with invasion of the stroma by KAI1 protein-negative cancer cells. The numbers of informative cases by microsatellite analysis were 14 (28.6%) of 49 at D11S1344 and 27 (55.1%) of 49 at D11S1326; none of 49 adenocarcinomas showed LOH or RERs at these loci. These results suggest that down-regulation of KAI1 mRNA expression rarely if ever involves LOH or RERs of the KAI1 gene region in primary lung adenocarcinoma.

Analysis of mec regulator genes in clinical methicillin-resistant Staphylococcus aureus isolates according to the production of coagulase, types of enterotoxin, and toxic shock syndrome toxin-1

The intrinsic resistance of methicillin-resistant Staphylococcus aureus (MRSA) is frequently explained by the production of an additional penicillin-binding protein (PBP), which is encoded by the mecA gene. The mec regulator genes, mecR1 and mecI, was identified in mecA-carrying Staphylococcus aureus N315. Between February and March, 1993, 179 clinical MRSA isolates were collected from institutions in Hiroshima prefecture. According to serological types of coagulase, enterotoxins, and toxic shock syndrome toxin-1 (TSST-1) productions, these strains were classified into 6 groups. In 53 strains chosen from all groups, mec regulatory gene distributions were divided into two groups; one with whole regulatory genes and another with the lacking region, including 3'-partial region of the mecR1 gene and mecI gene. This same deletion was detected across the different groups, suggesting that the deletion occurred at the ancestral strain before branching according to coagulase or enterotoxin productions. The strains with this lacking region showed a high-level of resistance to methicillin, while the strains with whole regulatory genes consisted of low and high levels of resistant strains. The highly resistant strains with whole regulatory genes were found to harbor a point mutation in the mecI gene. The basal levels of mecA gene transcription were elevated in the strains with the lacking region or the mecI point mutations. These data suggest that deletion or mutation of the mecI gene, the repressor on the mecA gene, might play an important role in methicillin resistance in clinical isolates of MRSA.

Surgical approaches for pancreatic ascites: report of three cases

Pancreatic ascites can occur in association with the rupture of a pseudocyst or the disruption of a pancreatic duct during the natural course of chronic pancreatitis. We report herein the successful treatment of three patients with pancreatic ascites by performing a surgical procedure after 4-6 weeks of total parenteral nutrition (TPN) proved ineffective. The principles of our surgical procedure for pancreatic ascites are as follows: (1) minimum pancreatic tissue is resected; (2) surgical intervention to repair leaking sites is not necessary; (3) pancreatic duct drainage is facilitated by an intestinal Roux-en-Y loop; (4) An external drainage tube is inserted through the Roux-en-Y loop into the main pancreatic duct. All three patients who underwent our surgical procedure had a good outcome. Although the mean follow-up time is still only 18.3 months, their condition has improved, with no evidence of recurrent ascites. Thus, our surgical procedure should be considered as an appropriate treatment for pancreatic ascites because it can be applied for all types of leakage, including leakage from the posterior wall of pancreas; it preserves pancreatic function, especially endocrine function; and it enables preservation of the spleen.

Rapid detection of MYCN gene amplification and telomerase expression in neuroblastoma

Amplification of the MYCN gene and high telomerase activity predict a poor prognosis for the patients with neuroblastoma. We used PCR techniques for rapid detection of MYCN gene amplification and human telomerase reverse transcriptase (hTERT) expression in neuroblastoma specimens. The detection of MYCN gene amplification is based on differential PCR in which three primer pairs were used to coamplify a 178-bp fragment of target MYCN gene with two reference gene fragments, a 237-bp of p53 exon 7 and a 120-bp of beta-globin exon 3, in a single tube of 40 surgically resected tumor samples. MYCN amplification was identified by this differential PCR in all 10 samples carrying more than 10 copies (already known to have MYCN gene amplification by Southern blot analysis). There were no false-negative or false-positive cases, and the relative intensity of MYCN bands in the differential PCR correlated significantly with the copy number determined by Southern blot analysis (y = 0.99, P<0.0001). This protocol was also applicable in the biopsy or aspirated samples, as well as the paraffin-embedded tissues, and in detecting intratumoral heterogeneity. Using RT-PCR procedures, hTERT mRNA expression was detectable in all 13 tumors with high telomerase activity. These nonradioisotopic PCR-based protocols for detecting MYCN gene amplification and hTERT mRNA expression are rapid and reliable and are likely to be useful to determine the biological behavior of neuroblastoma.

Genetic analysis with calcium-induced calcium release test in Japanese malignant hyperthermia susceptible (MHS) families

Some genetic studies have shown a linkage between malignant hyperthermia susceptibility (MHS) and chromosome 19q or the skeletal muscle ryanodine receptor (RYR1) gene. Some types of MHS seem to be caused by an abnormality of calcium-induced calcium release (CICR). We analyzed the linkage of RYR1 gene polymorphisms in Japanese MHS families and investigated the correlation between genetic evidence of RYR1 gene mutations and an accelerated rate of CICR. We studied 63 subjects who were referred to our institute for investigation of MHS. CICR rates were measured by the skinned fiber method in 23 subjects. DNA samples were collected from 63 individuals belonging to 22 unrelated families. Restriction fragment length polymorphism (RFLP) analyses on the RYR1 locus and hypervariable microsatellite analysis were performed. We found one family with a linkage between acceleration of the CICR mechanism and a group of RFLPs. In CICR tests, ten of the 11 patients who had presented with fulminant MH showed accelerated rates of CICR. Analysis for the mutation C1840T, which was performed in 63 samples, did not demonstrate an alteration in any of the patients. Although we found heterozygotes in RFLP studies, we did not recognize a specific relationship between the acceleration of CICR and the RFLPs. We suggest a linkage between the acceleration of CICR and an abnormal human RYR1 gene in MHS. These results also suggest that heterogeneity exists for MH. We conclude that genetic tests cannot replace CICR tests or caffeine-halothane contracture tests with muscle biopsy as a diagnosing test for MH in the near future.