Effect of probucol on intracellular pH and proliferation of human vascular endothelial cells

We investigated the effect of probucol on the intracellular pH ([pH]i) and proliferation of human umbilical vein endothelial cells (HUVEC), as well as their production of prostacyclin (PGI2). The addition of probucol produced a biphasic shift in [pH]i, with a brief initial acidification followed by a rapid alkaline shift. After pretreatment with EGTA, the initial decrease in [pH]i was abolished, and the subsequent increase was inhibited. After pretreatment with amiloride, only the increase of [pH]i was abolished. These results suggest that the probucol-induced increase of [pH]i was mainly dependent on Na+/H+ exchange and partly on extracellular Ca2+. In contrast, the addition of LDL produced a decrease of [pH]i. Under Ca2+-free condition, [pH]i was further decreased by LDL. In cells pretreated with amiloride, however, [pH]i was not further decreased by LDL. It was found that probucol promoted cell proliferation, and LDL inhibited cell proliferation. Addition of probucol also enhanced prostacyclin generation by HUVEC. This enhancement of PGI2 generation resulted from increased release of Ca2+ from the storage sites, due not only to increased production of inositol 1,4,5-triphosphate (IP3) but also to the increase of [pH]i. These findings may help to explain the antiatherosclerotic action of probucol.

Induction of cyclooxygenase-2 in human synovial cells by beta 2-microglobulin

BACKGROUND

Prostaglandins (PGs) are important mediators of inflammation in arthritis. We evaluated the role of the cycloxygenase-2 (COX-2) enzyme, which regulates PG biosynthesis, in osteoarthropathy associated with hemodialysis-associated amyloidosis (HAA) by characterizing COX-2 expression in beta 2-microglobulin-treated human synovial cells.

METHODS

We examined the effects of beta 2-microglobulin (beta 2m), a major constituent protein of amyloid fibrils in HAA, on the COX-2 protein and mRNA expression in human synovial cells using Western blot and reverse transcriptase-polymerase chain reaction.

RESULTS

beta 2m selectively increased the biosynthesis of COX-2 protein and induction of COX-2 mRNA in a dose-dependent manner. Immunoabsorption of beta 2m-containing media by anti-beta 2m-specific antibody abrogated beta 2m-mediated COX-2 expression on synovial cells. On the other hand, dexamethasone markedly suppressed the induction of COX-2 protein and mRNA in beta 2m-stimulated synovial cells.

CONCLUSIONS

Our results suggest that induction of COX-2 expression by beta 2m may be an important component of the inflammatory process in hemodialysis-associated osteoarthropathy.

Induction of cytokines in a human colon epithelial cell line by Shiga toxin 1 (Stx1) and Stx2 but not by non-toxic mutant Stx1 which lacks N-glycosidase activity

Stx1 and Stx2 produced by Shiga toxin-producing Escherichia coli are cytotoxic due to their N-glycosidase activity on 28S rRNA. In this study, we have shown that proinflammatory cytokine mRNAs, especially IL-8, were induced by Stx1 and Stx2 in Caco-2 cells. A non-toxic mutant of Stxl which lacks N-glycosidase activity did not induce cytokine mRNAs. IL-8 production at the protein level was enhanced by Stx1 and Stx2, but not by the mutant Stx1. These results demonstrate that Shiga toxins induce expression and synthesis of cytokines in Caco-2 cells and their N-glycosidase activity is essential for the induction.

Anterior transhepatic approach for isolated resection of the caudate lobe of the liver

We have devised a new technique for isolated caudate lobe resection in which we access the caudate lobe by separating the liver parenchyma along the interlobar plane. The safety and radicality of the procedure were evaluated in five patients: four with hepatocellular carcinoma (HCC) and one with metastatic rectal cancer. All of the tumors were located mainly in the paracaval portion of the caudate lobe. The patients with HCC (three of four) underwent an anatomic caudate lobe resection by identification of the right margin of the caudate lobe. Two patients required red blood cell transfusion, and one showed bile leakage after surgery. All of the patients are alive without recurrence more than 4 years after surgery, except one with rectal carcinoma who developed lung metastases. The anterior transhepatic approach is a safe and potentially curative surgical option for a tumor in the paracaval portion of the caudate lobe.

Antiarrhythmic effects of magnesium on rat papillary muscle and guinea pig ventricular myocytes

1. Despite widespread use of magnesium ion (Mg2+) for antiarrhythmic purposes, little direct information is available regarding its antiarrhythmic mechanisms. To elucidate the possible cellular mechanism, the effects of Mg2+ on early afterdepolarization (EAD), delayed afterdepolarization (DAD), triggered activity (TA), transient inward current (TI) and aftercontraction (AC) were examined in various cardiac preparations. The effects of Mg2+ on myoplasmic Ca2+ concentration were also studied. 2. The effects of Mg2+ on AC, induced by overdrive stimulation, were studied in isolated rat ventricular papillary muscle superfused with low K+ solution. In enzymatically isolated guinea pig myocytes, EAD, DAD and/or TA were induced after overdrive stimulation under conditions of superfusion with low K+ solution, using the whole-cell current-clamp method, and TI was also induced by the whole-cell voltage-clamp method. 3. Immediately after changing the solutions, containing varying concentrations of Mg2+, the effects of Mg2+ were examined. In addition, effects of Mg2+ on Ca transient were studied, using fura-2. 4. We found that: (1) in the rat papillary muscle, 10 mM Mg2+ effectively inhibited AC, which was produced after stimulation at both 3.3 Hz and 5 Hz, although 5 mM Mg2+ was without effect in the case of AC induced after 5-Hz stimulation; (2) in the myocytes, 5 mM Mg2+ did not inhibit DADs, EADs and TA, but 10 mM Mg2+ inhibited them completely; (3) the amplitude and frequency of TI decreased significantly in the presence of 10 mM Mg2+; and finally (4) 10 mM Mg2+ inhibited the Ca transient underlying DAD and/or TA. 5. The findings suggest, but do not prove unequivocally, that Mg's actions are probably due to a combination of a shift of the threshold of various ion channels to less negative potentials, a decrease in Ca2+ influx via Ca channels, a block of several K channels, and/or a block of Na-Ca exchanger. In conclusion, the present study indicates that extracellular Mg2+, via whatever mechanism, exerts antiarrhythmic activities.

Early hepatocellular carcinoma as an entity with a high rate of surgical cure

Early hepatocellular carcinoma (HCC) has been defined as a well-differentiated cancer containing Glisson's triad, but it remains unknown whether this lesion is curable. We prospectively studied 70 patients (enrolled from 1,172 referrals between 1982 and 1991) who had a diagnosis of a single HCC 2 cm or less in diameter (Stage T1) and who underwent curative hepatectomy and long-term follow-up (range, 0.2 to 14.3 years). Patients were eligible for surgery if they had a tumor that met the diagnostic criteria for HCC and were in Child-Pugh class A (n = 59) or B (n = 11) status. Among the 70 patients, there was 1 operative death. Based on our typing system, the tumors were assigned as early HCC (n = 15), overt HCC (n = 52), and non-HCC tumor (n = 3). The rate of microscopic regional spread was lower in early HCCs than in overt HCCs (7% vs. 42%; P = .01). The early HCC group had a longer time to recurrence than did the overt HCC group (3.9 vs. 1.7 years; P < .001) and had no local recurrence. After a median follow-up of 6.3 years, both overall survival and recurrence-free survival in the early HCC group were significantly better than those in the overt HCC group (P = .01; P = .001). In these two groups, the 5-year rates of overall survival were 93% and 54% (P = .01), and those of recurrence-free survival were 47% and 16% (P = .05), respectively; a significant survival benefit persisted over a decade (57% vs. 21%; P = .05). The early HCC group was at a lower risk of recurrence (relative risk, 0.31; 95% CI, 0.15 to 0.65; P = .002) and death (relative risk, 0.26; 95% CI, 0.09 to 0.73; P = .01) than was the overt HCC group. Early HCC is a distinct clinical entity with a high rate of surgical cure, thereby justifying its definition. It can be a lesion that corresponds to "Stage 0" cancer in other organs.

Rapid spread of the new clone of Vibrio cholerae O1 biotype El Tor in cholera endemic areas in India

Using molecular techniques, we investigated whether the clone of Vibrio cholerae O1 biotype El Tor which appeared in Calcutta, India, in 1994 has spread to other cholera endemic areas in the country. The ribotype of 31 of the 33 strains isolated from different parts of India during 1996 and 1997 was identical to the ribotype displayed by the new clone of V. cholerae O1 which emerged in Calcutta in 1994. Likewise, 12 of the 15 strains examined by pulsed-field gel electrophoresis (PFGE) showed identical profile to that exhibited by the new clone of O1. The restriction fragment length polymorphism (RFLP) of CTX genetic element of these strains also matched with the new clone of O1 which emerged after the outbreak of V. cholerae 0139 in Calcutta. However, two strains (AH042 and AH046) isolated from an outbreak in Ahmedabad (western India) showed different CTX RFLP but had the same ribotype and PFGE profile as the new clone, whereas one strain from Goa (G2) showed distinct ribotype and PFGE profile and the CTX RFLP was identical to the O1 strains which prevailed before the genesis of 0139 in Calcutta. The drug resistance pattern of most of the O1 strains examined in this study, except strain G2, was similar to that of the new clone of V. cholerae O1. None of the strains in this study carried plasmids. Molecular studies clearly show that the new expanded drug resistant clone of V. cholerae O1 has spread to all cholera endemic areas in India and also provide evidence for the evolution of new clones of the O1 serogroup.

B-cell lymphoma of mucosa-associated lymphoid tissue of the thymus: a report of two cases with a background of Sjögren's syndrome and monoclonal gammopathy

Two rare cases of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in the thymus are reported. Both patients (a 61-year-old man and a 75-year-old woman) were suffering from Sjögren's syndrome and immunoglobulin (Ig)A kappa monoclonal gammopathy. Mixed IgA-IgG cryoglobulinemia was also present in the male case. Tumor cells expressed IgA and kappa antibody reactive proteins identical with serum IgA kappa M. Moreover, we could demonstrate rearrangements of the immunoglobulin heavy and light chain genes, which supported the monoclonal origin of tumor cells. Immunological abnormalities improved after thymectomy in one case in which the tumor cells were confined to the thymus, but not the other with regional lymph node involvement, suggesting a causal role for the tumor. MALT lymphomas of the thymus thus appear to be associated with immunological disorders such as Sjögren's syndrome or monoclonal gammopathy.

Identification and characterization of a newly isolated shiga toxin 2-converting phage from shiga toxin-producing Escherichia coli

Shiga toxins 1 (Stx1) and 2 (Stx2) are encoded by toxin-converting bacteriophages of Stx-producing Escherichia coli (STEC), and so far two Stx1- and one Stx2-converting phages have been isolated from two STEC strains (A. D. O'Brien, J. W. Newlands, S. F. Miller, R. K. Holmes, H. W. Smith, and S. B. Formal, Science 226:694-696, 1984). In this study, we isolated two Stx2-converting phages, designated Stx2Phi-I and Stx2Phi-II, from two clinical strains of STEC associated with the outbreaks in Japan in 1996 and found that Stx2Phi-I resembled 933W, the previously reported Stx2-converting phage, in its infective properties for E. coli K-12 strain C600 while Stx2Phi-II was distinct from them. The sizes of the plaques of Stx2Phi-I and Stx2Phi-II in C600 were different; the former was larger than the latter. The restriction maps of Stx2Phi-I and Stx2Phi-II were not identical; rather, Stx2Phi-II DNA was approximately 3 kb larger than Stx2Phi-I DNA. Furthermore, Stx2Phi-I and Stx2Phi-II showed different phage immunity, with Stx2Phi-I and 933W belonging to the same group. Infection of C600 by Stx2Phi-I or 933W was affected by environmental osmolarity differently from that by Stx2Phi-II. When C600 was grown under conditions of high osmolarity, the infectivity of Stx2Phi-I and 933W was greatly decreased compared with that of Stx2Phi-II. Examination of the plating efficiency of the three phages for the defined mutations in C600 revealed that the efficiency of Stx2Phi-I and 933W for the fadL mutant decreased to less than 10(-7) compared with that for C600 whereas the efficiency of Stx2Phi-II decreased to 0.1% of that for C600. In contrast, while the plating efficiency of Stx2Phi-II for the lamB mutant decreased to a low level (0.05% of that for C600), the efficiencies of Stx2Phi-I and 933W were not changed. This was confirmed by the phage neutralization experiments with isolated outer membrane fractions from C600, fadL mutant, or lamB mutant or the purified His6-tagged FadL and LamB proteins. Based on the data, we concluded that FadL acts as the receptor for Stx2Phi-I and Stx2Phi-II whereas LamB acts as the receptor only for Stx2Phi-II.

Imaging of large early and early advanced hepatocellular carcinomas of more than 5 cm in diameter: report of two cases

In an attempt to clarify the imaging characteristics of large early and early advanced hepatocellular carcinoma (HCC), we present two such cases which were greater than 5 cm in diameter. One case had four early HCCs and the other had early advanced HCC which was followed for five years and nine months. Multiphasic CT, CT arteriography (CTA), CT arterial portography (CTAP), and MR imaging were performed. Early HCC was shown as a low density mass by multiphasic contrast CT, CTAP and as a hyperintense mass on a T1-weighted image (WI) and isointense on T2WI. Early advanced HCC was demonstrated as a hypodense mass with hyperenhancing interior nodules on CTA, and isodense with hypodense internal foci on CTAP. One follow-up case showed a multi-step progression from early to early advanced HCC, and finally to overtly advanced HCC. Despite the unusually large size of these two tumors, the findings of multiphasic CT, CTA, CTAP, and MR imaging were consistent with those seen in common-sized (less than 2 cm) early and early advanced HCCs. Multi-step progression of hepatocarcinogenesis was observed in one case.

Clinical study on accentuated antagonism in the regulation of heart rate in children

Facial immersion testing in cold water (< 4 degrees C) was performed to study the responses of sinus cycle length to increased parasympathetic tone before and 5 min after exercise testing in 27 children. There were no episodes of sinus arrest or extrasystole during the facial immersion testing. The resting sinus cycle lengths were significantly shorter after (539 +/- 68 msec) than before (597 +/- 96 msec) exercise testing (p < 0.001). The maximal sinus cycle lengths before and after exercise testing during cold water facial immersion testing did not differ significantly (928 +/- 167 msec and 909 +/- 128 msec, respectively). Vagal chronotropic responses were calculated from the control sinus cycle lengths and the maximal sinus cycle lengths during facial immersion testing. Facial immersion caused greater prolongation of sinus cycle length after than before exercise (73 +/- 27% and 54 +/- 26%, respectively; p < 0.005). We speculate that this augmentation of vagal activity represents accentuated antagonism in these children, i.e., the same parasympathetic stimulus causes a greater response in the presence of a stronger background sympathetic activity.

Needle tract implantation of hepatocellular carcinoma after percutaneous ethanol injection

BACKGROUND

Percutaneous ethanol injection (PEI) therapy currently is widely used for small hepatocellular carcinoma (HCC). However, only limited information is available regarding needle tract implantation after PEI treatment.

METHODS

Records of HCC patients who underwent PEI between March 1990 and April 1997 at the National Cancer Center Hospital (n = 177) were reviewed to clarify the incidence, risk factors, and outcome of needle tract implantation of HCC.

RESULTS

PEI was performed for 348 HCC patients with a median tumor size of 20 mm. Needle tract implantation was found in 4 patients (10, 13, 15, and 46 months, respectively, after PEI). The size of the PEI-treated HCC tumors in these patients was 20, 27, 28, and 30 mm, respectively, in greatest dimension. All tumors were enhanced in the early phase on dynamic computed tomography (CT), and were found to have moderate tumor cell differentiation on biopsied specimens. Of the four implanted tumors, three were resected and the remaining tumor was treated with extrabeam radiotherapy. At last follow-up, 2 of the 4 patients had died (1 of variceal bleeding 60 months after PEI and the other from cancer 61 months after PEI) and 2 were still alive (14 and 20 months, respectively, after PEI) with no evidence of active tumor.

CONCLUSIONS

Needle tract implantation after PEI is not unusual, especially when HCC tumors are > or =2 cm in greatest dimension, enhanced in the early phase on dynamic CT, and/or moderately differentiated on biopsied specimens.

[Epidemiological study on penicillin-resistant Streptococcus pneumoniae]

We studied the differences among clinical isolates of Penicillin-resistant Streptococcus pneumoniae by polymerase chain reaction (PCR) of pbp2b gene, followed by serotyping and pulsed field gel electrophoresis (PFGE) analysis. Clinical isolates were recovered from sputum samples from patients with respiratory infection in Tottori University Hospital between June 1986 and May 1996. By PCR, altered pbp2b genes of the resistant isolates were detected in 76.5%. The percentages of the isolates that had altered pbp2b genes increased concomitantly with the minimum inhibitory concentration (MIC). By serotyping the percentage of 19F, 23F, 6B and 14 was 54.5%, 18.2%, 9.1% and 9.1% respectively. The frequency of isolates resistant to penicillin increased rapidly from 1991 in this hospital and most isolates belonged to serotype 19F. The resistant isolates in this hospital and 4 clinical resistant isolates of S. pneumoniae 19F in a second hospital were studied by PFGE. 14 of 18 resistant 19F isolates in this hospital and all 19F isolates from the second hospital presented an identical pattern. The remaining 4 samples were similar though not completely identical. These results indicate that the penicillin resistant 19F isolates have a common clonal origin and have spread rapidly from 1991 in this hospital.

[Systematic resection for hepatocellular carcinoma]

We have performed systematic subsegmentectomy in patients with hepatocellular carcinoma complicated mainly by cirrhosis. Such small anatomical resections have become possible due to the introduction of intraoperative ultrasonography and of vascular occlusion techniques. As a result of our clinical experience involving 163 cases, it has been clarified that subsegmentectomy is a safe procedure (operative mortality rate, 0.6%) and results in a favorable long-term outcome (5-year survival rate, 51%). In the resected specimens, microscopic cancer spread was recognized frequently (portal venous invasion, 41%; intrahepatic metastasis, 31%). Subsegmentectomy is therefore the first procedure of choice in patients who have small hepatocellular carcinoma and chronic hepatitis or cirrhosis.

Cyclophosphamide given after active specific immunization augments antitumor immunity by modulation of Th1 commitment of CD4+ T cells

BACKGROUND AND OBJECTIVES

In order to evaluate the regulatory effect of cyclophosphamide (CPA) on active specific immunization (ASI)-induced antitumor immunity, we examined the timing of CPA (100 mg/kg) with ASI, and focused on whether CPA given after ASI augments antitumor immunity by modulation of Th1 commitment of CD4+ T cells.

METHODS

We examined the effect of CPA combined with ASI using sonicated tumor supernatant (SS) and recombinant interleukin-1 beta (rIL-1 beta).

RESULTS

Survival of i.p. tumor inoculated mice after ASI (days -12, -9, and -6) followed by 100 mg/kg CPA (day -3) (ASI-CPA) was significantly prolonged compared with that of mice treated with ASI alone, whereas CPA (day -15) treatment before ASI (CPA-ASI) completely abrogated the survival prolongation by ASI alone. In early stage (day 0) after ASI-CPA treatment, the CD4+ T cells were determined to play an important role in the protective immunity for the following reasons: 1) the CD4+/CD8+ ratio of spleen cells from immunized mice was higher than that of the control or CPA alone treated group; and 2) the tumor neutralizing activity of fresh spleen cells was abrogated by CD4+ T-cell depletion in vitro. CD4+ T cells of mice treated with ASI-CPA produced more interferon (IFN)-gamma and IL-2 and less IL-4 than those of the ASI alone group.

CONCLUSIONS

These results suggest that the protective immunity induced by ASI was augmented through the modification of the Th1 and Th2 balance by CPA injection after ASI.

[Long-term results after hepatectomy for hepatocellular carcinoma according to cancer stage]

The survival rates after hepatectomy for hepatocellular carcinoma (HCC) according to cancer stage were reported. The 5-year survival rates of Stage 1, 2, 3 and 4 were 69.6%, 54.2%, 35.9% and 30.2%, respectively. A significant difference was observed between any neighboring two stages. But more than 5 years till 20 years, the survival curves cross at some times. That means after 5 years the influence of the anatomic condition of the initial cancer has been weak. Probably another factor which controls multi-centric carcinogenesis of HCC may work. When the survival rate was calculated dividing the stage group into two sub-groups according to liver function, with good function or poor function, the survival of the poor liver function group of any stage group was worse than that of the good liver function group of the nearest worse stage group. The survival after hepatectomy of HCC depends not only upon anatomic condition of the cancer but also upon the liver function.

Molecular analysis of non-O1, non-O139 Vibrio cholerae associated with an unusual upsurge in the incidence of cholera-like disease in Calcutta, India

There was an inexplicable upsurge in the incidence of non-O1, non-O139 Vibrio cholerae among hospitalized patients admitted to the Infectious Diseases Hospital, Calcutta, India, between February and March 1996. Of the 18 strains of V. cholerae isolated during this period, 15 belonged to the non-O1, non-O139 serogroups (4 belonged to O144, 3 belonged to O11, 1 each belonged to O6, O8, O12, O19, O39, and O58, and 2 strains could not be typed), 2 belonged to the O139 serogroup, and 1 belonged to the O1 serogroup. Cell-free culture supernatants of 13 representative non-O1, non-O139 V. cholerae strains evoked a distinct cytotoxic effect on CHO and HeLa cells, and the strains examined produced the nonmembrane-damaging cytotoxin. By several PCR assays, it was determined that none of the non-O1, non-O139 strains were positive for the ctxA, zot, ace, and tcpA genes and for the genes representing the heat-labile toxin, heat-stable toxin, and verotoxin of Escherichia coli and the various variants of these genes. Studies on the clonality of non-O1, non-O139 V. cholerae strains by restriction fragment length polymorphism (RFLP) analysis of rRNA genes and of other genes (hlyA, hlyU, hlx, toxR, and attRS1) and by pulsed-field gel electrophoresis (PFGE) collectively indicate that the upsurge which occurred in February and March 1996 was caused by strains belonging to different clones. Overall, there was an excellent correlation between the results of ribotyping, RFLP analysis of various genes, and PFGE, with strains belonging to a particular serogroup showing nearly identical restriction patterns and PFGE profiles. It is clear from this study that some serogroups of V. cholerae can cause diarrhea by a mechanism quite different from that of toxigenic V. cholerae O1 and O139, and we have proposed the nomenclature of enteropathogenic V. cholerae to include these serogroups.

Development and evaluation of a multiplex PCR assay for rapid detection of toxigenic Vibrio cholerae O1 and O139

A multiplex polymerase chain reaction assay was developed for concurrent detection of rfb sequences specific for the O1 and the O139 serogroups of Vibrio cholerae and for ctxA specific sequences. The multiplex PCR assay was found to be highly specific and sensitive and was capable of detecting 65 cfu and 200 cfu per assay of V. cholerae O1 and O139, respectively. Evaluation of the multiplex PCR assay using 121 stool samples from patients admitted to the Infectious Diseases Hospital, Calcutta, showed the assay to be 100% sensitive and 95.2% specific when the culture method was taken as the standard. In addition to the 38 PCR positive stool samples, an additional four samples which were negative by culture method but positive by PCR assay belonged to the O139 serogroup. All the 38 stool samples positive for either O1 or O139 serogroup by PCR assay were also positive for the ctxA amplicon indicating that the O1 and O139 V. cholerae strains have the genetic potential of producing cholera toxin.

[TNM classification--pediatric tumors]

The clinical and postsurgical TNM classifications (cTNM and pTNM) for neuroblastoma (NB), nephroblastoma (WT) and soft tissue sarcomas were presented in 1982 by the TNM Committee in UICC in collaboration with SIOP. The Japanese TNM Committee proposed new pTNM systems (J-pTNM) for NB and WT, and new cTNM and pTNM system for primary liver carcinoma in infants and children (HT). These pTNMs were based on the staging systems developed by the Malignant Tumor Committee of the Japanese Society of Pediatric Surgeons. The proposal of subdivision of M category in NB was presented for testing the new telescopic ramifications of TNM. The TNM for HT was added as a new classification recommended for testing. The effectiveness of these TNM systems was assessed using NB, WT and hepatoblastoma (HB) cases which were registered in collaborating institutes. The analyses suggested that pTNM, especially the J-pTNM system in NB, WT and HT were effective for the assessment of prognoses, although cTNM systems were not enough to assess the extent of the disease.

Neuroleptic malignant syndrome in parkinsonian patients: risk factors

A syndrome resembling the neuroleptic malignant syndrome (NMS) is known to develop occasionally following interruption of dopaminergic medications in patients with Parkinson's disease. However, NMS can develop even without withdrawal of antiparkinsonian drugs. In parkinsonian patients who continually received dopaminergic medications, the development of NMS occurred exclusively in warm seasons, May to August. The development of NMS could occur at any season in association with the cessation of dopaminergic drugs. A female parkinsonian patient showed two episodes of NMS during the premenstrual period. It is suggested that hot weather or dehydration and aggravation of parkinsonism premenstrually constitute risk factors for the development of NMS, in addition to withdrawal of antiparkinsonian drugs.

Comparison between the multiplex PCR, sensitivity to biotype specific phages & polymyxin B for biotyping of Vibrio cholerae O1

A total of 196 Vibrio cholerae O1 strains isolated between 1970 and 1996 were biotyped by multiplex PCR, susceptibility to polymyxin B and sensitivity to biotype specific phages. We modified the multiplex PCR by increasing the primer concentration of tcpA to improve the results. Comparison of the results of modified multiplex PCR and sensitivity to biotype specific phages and to polymyxin B showed that multiplex PCR was as efficient as phage typing for biotyping of V. cholerae O1. All the strains of V. cholerae O1 could be accurately distinguished based on polymyxin B sensitivity. Thus our results show that susceptibility of strains of V. cholerae O1 to polymyxin B is the easiest method to biotype V. cholerae O1 and is feasible in most laboratories when compared with multiplex PCR and sensitivity to biotype specific phages.

Loss of biological activity due to Glu-->Arg mutation at residue 11 of the B subunit of cholera toxin

Since it has been reported that a single amino acid mutation of Gly-->Arg in the CAGYC region of the beta chain of human thyroid stimulating hormone (hTSH) was responsible for congenital isolated TSH deficiency, and that the same amino acid substitution in this site of hTSH and human chorionic gonadotropin (hCG) introduced by site-directed mutagenesis resulted in loss of activity, the authors studied the role of glutamic acid at position 11 (Glu-11) from the N-terminus of the B subunit of cholera toxin (CT), which corresponds to the glycine in the CAGYC region of the beta chain of hTSH and hCG. A mutant CT constructed by site-directed mutagenesis in which Glu-11 was replaced by Arg (CT-E11R) did not induce either morphological changes or accumulation of cytosolic cyclic AMP in Chinese hamster ovary cells, although it formed the holotoxin AB5, retained the ability to bind to GM1-ganglioside and showed ADP-ribosyltransferase activity. Weak assembly of the B subunits in mutant CT-E11R demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under non-heating conditions might explain the loss of biological activity.

The effectiveness of active specific immunotherapy using interferon-gamma-gene-transduced tumor cells in a murine tumor model

Active specific immunotherapy was examined in BALB/c mice using sonicated tumor extract(SE) from plasmacytoma MOPC104E or interferon-gamma-(IFN-gamma)-gene-transduced MOPC104E (Mu gamma), employing interleukin-1 (IL-1) as an adjuvant. Subcutaneous (s.c.) MOPC104E tumor growth was significantly suppressed in mice given a single preimmunization of IL-1 plus Mu gamma-SE, 9 days prior to inoculation, whereas the tumor growth in mice similarly pretreated with IL-1 alone or IL-1 plus MOPC104E-SE(MOPC-SE) was not affected; the mean tumor diameters on day 21 being 6.8 mm, 15.3 mm, and 13.2 mm, respectively. Two-dose preimmunization with Mu gamma-SE alone or IL-1 alone given 10 and 7 days prior to s.c. inoculation also resulted in profound suppression of tumor growth compared to the control. As postsurgical immunization, MOPC104E cells were injected into the foot pads of mice, followed by amputation of the tumor-bearing foot 20 days later, then treatment with IL-1 plus MOPC-SE or IL-1 plus Mu gamma-SE on days 4, 7, and 10 after the amputation. The mean survival of the mice treated with IL-1 plus Mu gamma-SE was significantly prolonged compared to that of the mice treated with IL-1 plus MOPC-SE, at 90.3 days vs 40.9 days, respectively (P < 0.05 by the Cox-Mantel test). These results suggest that SE prepared from IFN-gamma-gene-transduced MOPC104E is more effective for active specific immunotherapy than SE prepared from MOPC104E.

Hepatocellular carcinoma with gastrointestinal hemorrhage caused by direct tumor invasion to the duodenum

Gastrointestinal hemorrhage from hepatocellular carcinoma invading the duodenum is very rare. A 60-year-old man with multiple hepatocellular carcinoma was admitted to our hospital because of massive melena and hematemesis. We succeeded in hemostasis of an esophageal variceal rupture by endoscopic varicial ligation. The duodenum could not be observed endoscopically due to extramural compression to the stomach from the liver tumor. Massive gastrointestinal hemorrhage occurred again and the patient died of hepatic failure. The postmortem examination revealed that the liver tumor had invaded the second portion of the duodenum and perforated into the lumen.