[A case of deep sylvian meningioma presenting temporal lobe epilepsy]

A rare case of deep sylvian meningioma is presented. A 62-year-old woman was admitted to our hospital because of one year history of temporal lobe epilepsy. She had no neurological deficit except for EEG abnormality. CT scans showed a small calcified mass in the left temporal lobe adjacent to the sylvian fissure with no enhancement by contrast medium. The mass was low-intense in both T1- and T2-weighted MR images. The T1-weighted image after the infusion of gadolinium revealed enhancement of the middle cerebral artery adjacent to the mass, similar to dural tail sign. Left external carotid angiography did not show any tumor stain nor the dilatation of the middle meningeal artery. Left internal carotid angiography disclosed enlarged middle cerebral artery without tumor stain. A left frontotemporal craniotomy was performed and the mass was totally removed. The tumor was located deep in sylvian fissure without any connection to the dura or ventricular system, which was firmly adherent to the middle cerebral artery. The histological examination of the surgical specimen revealed a psammomatous meningioma. Meningiomas are believed to originate from the arachnoid cap cells and can arise from various intracranial locations where arachnoid cap cells exist. The majority of them are attached to the dura, choroid plexus, or the tela choroidea. Only eleven cases of deep sylvian meningiomas have been presented in the literature. We have reviewed the clinical and radiological findings in such meningiomas. MR findings in deep sylvian meningioma have not been described.(ABSTRACT TRUNCATED AT 250 WORDS)

Event-related changes of background electroencephalogram during contingent negative variation paradigm

The autoregressive model was applied to the background electroencephalogram during the tone(S1)-tone(S2)-respond contingent negative variation paradigm under eyes-open condition. The EEG data were obtained at the scalp sites of Fz, Cz, and Pz in seven normal males. During the first half of the interstimulus interval (ISI) of 2.5 s, Fz-dominant excitatory process was suggested in concordance with an orienting response to stimulus 1. In the second half of the ISI, Pz-dominant inhibitory process was considered. The stimulus 2 presentation and the required motor response promoted the Pz-dominant process.

Role of nitric oxide in the development of thermal hyperesthesia induced by sciatic nerve constriction injury in the rat

BACKGROUND

Nitric oxide (NO) has been shown to be involved in mediating nociceptive information transmission in the spinal cord. It is known that the N-methyl-D-aspartate receptor plays an important role in the development of the spinal facilitation evoked by a protracted small afferent input and that this effect is mediated at least in part by NO. Recently, it has been found that N-methyl-D-aspartate receptor-mediated spinal facilitation is crucial in the development of thermal hyperesthesia evoked by a nerve constriction injury. In the current study, we investigated the role of NO in the development of thermal hyperesthesia after a nerve constriction injury.

METHODS

The Bennett and Xie model (four loose chromic gut ligations around the rat sciatic nerve) was used to examine the development of thermal hyperesthesia. An NO synthase inhibitor (N omega-nitro-L-arginine or N omega-nitro-L-arginine methyl ester hydrochloride), rat hemoglobin, or L-arginine was administered intrathecally 10 min before the nerve injury (pretreatment study) or 15 min after the nerve injury (posttreatment study).

RESULTS

Pretreatment but not posttreatment administration of NO synthase inhibitor significantly delayed the development of thermal hyperesthesia. The effect of NO synthase inhibitor was reversed by the coadministration of L-arginine but not by the coadministration of D-arginine. Pretreatment with rat hemoglobin also delayed the development of thermal hyperesthesia. L-Arginine itself had no effect on the development of thermal hyperesthesia.

CONCLUSIONS

NO may play an important role in the development of N-methyl-D-aspartate receptor-mediated spinal facilitation after a nerve constriction injury.

[High-resolution CT findings of Pneumocystis carinii pneumonia]

High resolution CT (HRCT) was performed on 7 patients with pneumocystis carinii pneumonia (PCP). Six cases were proven bacteriologically by bronchoalveolar lavage; one case was proven by autopsy. Three patients were re-scanned after specific treatment and symptomatic relief. All the CT scans were abnormal, usually showing bilateral diffuse ground-glass opacity, through which the pulmonary vessels remained visible. Chest X-ray, on the other hand, showed a normal pattern in one patient. Other changes such as air space consolidation (in 4 cases) and thickening of peripheral pulmona vessels (in 2 cases) were also seen. Air space consolidation was found in three cases with mixed infection (cytomegalovirus pneumonia in 2 cases, aspergillosis in one case). No patient showed significant mediastinal or hilar lymph node enlargement, pleural effusion or cystic pulmonary change. HRCT findings such as ground-glass opacity and air space consolidation were shown to disappear in some cases of PCP after specific treatment. HRCT is useful to evaluate the sequential pulmonary changes after the specific therapy.

[Acute bacterial meningitis and foramen magnum syndrome as a presentation of odontoid osteomyelitis. A case report]

A 77-year-old male was hospitalized with a 6-day history of severe posterior cervical pain and headache. An initial lumbar puncture revealed polymorphonuclear pleocytosis indicating pyogenic meningitis. The blood and throat cultures on admission were positive for Staphylococcus aureus. A combination of ceftriaxone and ABPC, both of which were sensitive to the pathogen, were intravenously administered for one month, by which he responded well as to the meningitis. However, he was found to have persistent neck pain, and wasting and weakness of the shoulder girdles, which were associated with polyneuropathy-like sensory loss. Neuroimaging studies disclosed a partial destruction of the odontoid process, subluxation of the atlantoaxial joint, MRI evidence of an inflammatory pseudomass formation dorsal to the odontoid process and an increased uptake of radionuclide on bone scanning, all of which were indicative of osteomyelitic processes at the region of the axis; i.e., the meningitis was thought to be secondary to osteomyelitis of the odontoid process and hence the foramen magnum syndrome characteristic to this particular case was explained by the compression of the cervicomedullary junction due to the pseudomass. To our knowledge, this is the first case of primary odontoid osteomyelitis to be reported in Japan.

Skin manifestations associated with rheumatoid arthritis

We examined cutaneous manifestations of rheumatoid arthritis (RA) of 142 Japanese patients who visited both the Departments of Dermatology and Rheumatology of our hospital. We classified cutaneous lesions into specific and/or characteristic or nonspecific ones. Nonspecific lesions predominated in our series. Among the specific skin manifestations, which comprised 10% of the total, rheumatoid nodules, rheumatoid papules, rheumatoid neutrophilic dermatitis, and severe vasculitic ulcers correlated with high titers of rheumatoid factors and progression of RA, while purpura and livedo did not. Nonspecific skin manifestations failed to correspond with the level of rheumatoid factors. Among the nonspecific lesions, asteatotic eczema, candida interdigitalis, and tinea unguium were commonly detected.

Apolipoprotein E phenotypes in patients with gout: relation with hypertriglyceridaemia

OBJECTIVE

To elucidate the relationship, if any, between lipid abnormalities and apolipoprotein E (apo E) polymorphism, by investigating apo E phenotype and allele frequency.

METHODS

Fasting blood samples were taken for determination of apo E phenotype and serum lipids in 221 male patients with gout and 141 control male subjects. Apo E phenotype was determined by one dimensional flat gel isoelectric focusing.

RESULTS

Frequencies of apo E phenotypes in gout were apo E3/3 67.9%, E4/3 18.1%, E4/4 2.3%, E4/2 1.8%, E3/2 9.5%, and E2/2 0.5%; those in control male subjects were 74.5%, 15.6%, 0%, 1.4%, 7.1%, and 1.4%, respectively. Frequencies of the e2, e3, and e4 alleles in gout were 0.061, 0.817 and 0.122, compared with the corresponding control frequencies of 0.057, 0.858 and 0.085. These differences in apo E phenotype and allele frequencies between gout and control subjects were not significant. The frequency of apo e4 allele in hyperlipidaemic gout subjects was significantly greater than that in normolipidaemic gout subjects; in contrast, its frequency was not different between hyperlipidaemic and normolipidaemic control subjects. Serum triglyceride, total cholesterol, apo B and E concentrations were significantly greater in gouty patients with the apo E4/3 phenotype than in those with gout having the apo E3/3 phenotype.

CONCLUSIONS

These data suggest that gout subjects with hyperlipidaemia (hypertriglyceridaemia, hypercholesterolaemia or both) possess the apo e4 allele with higher frequency than those with normolipidaemia. They also suggest that apo e4 may induce some susceptibility to the development of hyperlipidaemia in gout in addition to that induced by obesity or excessive alcohol consumption, and may contribute to the high prevalence of atherosclerotic diseases in gout patients.

Determination of plasma purine nucleoside phosphorylase activity by high-performance liquid chromatography

A high-performance liquid chromatographic method was developed for the determination of plasma purine nucleoside phosphorylase activity. In this method, the reaction mixture consisted of 15 microliters of plasma and 285 microliters of 50 mM phosphate buffer (pH 7.4) containing 3.8 mM inosine and 0.15 mM 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylic acid (strong xanthine oxidase inhibitor). After the reaction, the hypoxanthine produced was monitored to express plasma purine nucleoside phosphorylase activity. By this method, the activity of purine nucleoside phosphorylase was easily determined even with a small-volume plasma sample and despite its low activity in plasma. In addition, plasma purine nucleoside phosphorylase activity can be accurately determined even if the plasma is turbid. As a result, we were able to measure plasma purine nucleoside phosphorylase activity in patients with gout or asthma and healthy subjects, whereby it was demonstrated that plasma purine nucleoside phosphorylase activity was higher in patients with asthma than in either healthy subjects or patients with gout.

Sequence analysis of the germ-line VH gene corresponding to a nephritogenic antibody in MRL/lpr lupus mice

In order to investigate the genetic origin of nephritogenic antibodies in MRL/Mp-lpr/lpr (MRL/lpr) lupus mice, we isolated the germ-line heavy chain variable region (VH) gene corresponding to the nephritogenic antibody, B1, derived from an unmanipulated MRL/lpr mouse. Injection of this antibody into C.B-17/Icr-scid/scid mice resulted in the generation of wire loop-like glomerular lesions resembling those of lupus nephritis. Nucleotide sequences of this germ-line VH gene showed no replacement mutation in the VH region of the B1 antibody. Furthermore, this gene was identical to that found in the C3H/HeJ-lpr/lpr strain of mice. Our results suggest that germ-line VH genes can encode nephritogenic antibodies without somatic mutation, even in a mouse strain not prone to lupus.

Characteristic cytokines generated by keratinocytes and mononuclear infiltrates in oral lichen planus

Cytokine production was investigated in oral keratinocytes and tissue-infiltrated mononuclear cells (TIMC) obtained from patients with oral lichen planus (OLP). The numbers of cells producing interleukin (IL)-1 beta, IL-4, IL-6, granulocyte colony-stimulating factor, and tumor necrosis factor-alpha per 10(4) cells in keratinocytes from patients with OLP were determined by enzyme-linked immunospot assay. These levels were two to threefold greater than those in keratinocytes from chronically inflamed gingiva and 10 to 20-fold of those from the intact gingiva. The concentrations of these cytokines in the culture supernatants of keratinocytes were correlated with the number of cytokine-producing cells. Compared with TIMC in the gingiva and peripheral blood mononuclear cells, TIMC in OLP were more cytokine-productive, with larger numbers of cytokine-producing cells that expressed more cytokine messengers. More IL-6, IL-2, and IL-10 were generated from TIMC in OLP, whereas less granulocyte colony-stimulating factor was generated. After pretreatment with IL-2, TIMC from OLP patients generated more IL-6 than did peripheral blood mononuclear cells, and IL-4-pretreated TIMC from the patients released larger amounts of IL-2, IL-6, and IL-10. These results indicate that keratinocytes play a critical role in OLP through production of large amounts of cytokines, that TIMC are stimulated in situ and differentiated to produce cytokines characteristic of OLP, and that the inflammatory condition of OLP is determined by the local cytokine network.

Electrophysiologic determinants of ventricular rate in human atrial fibrillation

INTRODUCTION

The mechanisms of the ventricular response during atrial fibrillation (AF) remain uncertain. The parameters obtained during an electrophysiologic study, including atrial rates during AF, were analyzed to clarify further the determinants of the ventricular rate during AF.

METHODS AND RESULTS

Thirty patients without manifest preexcitation in whom AF was induced during electrophysiologic study were divided into two groups. Group 1 consisted of 20 patients (ages 55 +/- 10 years) without a dual AV nodal pathway. Group 2 consisted of 10 patients (ages 53 +/- 13 years) having a dual AV nodal pathway. The correlation coefficient between the mean RR interval during AF (mRR) and the mean intra-atrial potential interval during AF (mff) was positive (0.05 [P < 0.05] in group 1 and 0.37 [P = NS] in group 2). The correlation coefficient of the mRR against the functional refractory periods of the AV node (AVFRP) was 0.73 (P < 0.001) in group 1. The correlation coefficients between mRR and the fast AV nodal pathway functional refractory periods and the slow AV nodal pathway effective refractory periods (SPERP) were 0.58 (P = NS) and 0.7 (P < 0.05) in group 2, respectively. The correlation coefficients between mRR against (mff x AVFRP)1/2 in group 1 and (mff x SPERP)1/2 in group 2 were 0.8 (P < 0.001) and 0.72 (P < 0.05), respectively.

CONCLUSIONS

This clinical study did not indicate an inverse relation between the atrial and ventricular rates that had been reported by the previous experimental study. The ventricular rate during AF appeared to be quantitatively related to the atrial rate via AV node function. The importance of the slow pathway in determining the ventricular rate during AF was observed.

c-Myb repression of c-erbB-2 transcription by direct binding to the c-erbB-2 promoter

The c-myb proto-oncogene product (c-Myb) is a transcriptional activator that can bind to the specific DNA sequences. Although c-Myb also represses an artificial promoter containing the Myb binding sites, natural target genes transcriptionally repressed by c-Myb have not been identified. We have found that the human c-erbB-2 promoter activity is repressed by c-Myb or B-Myb in a chloramphenicol acetyltransferase co-transfection assay. Domain analyses of c-Myb suggested that Myb represses the c-erbB-2 promoter activity by competing with positive regulators of the c-erbB-2 promoter. In in vitro transcription assays, Myb proteins containing only the DNA binding domain could repress c-erbB-2 promoter activity. Two Myb binding sites in the c-erbB-2 promoter were critical for transcriptional repression by c-Myb. One of the two Myb binding sites overlaps the TATA box, and DNase I footprint analyses indicated that c-Myb can compete with TFIID. These results suggest that Myb-induced trans-repression of the c-erbB-2 promoter partly involves competition between Myb and TFIID.

Multiple promoters in rat acyl-CoA synthetase gene mediate differential expression of multiple transcripts with 5'-end heterogeneity

Nucleotide sequence analysis of six independently isolated cDNAs for rat acyl-CoA synthetase (ACS) revealed three forms of ACS mRNA, designated form-A, -B, and -C mRNAs, which differ in their 5'-untranslated regions. Form-A mRNA was preferentially detected in normal and peroxisome-induced livers, whereas form-B mRNA was found in peroxisome-induced livers but not in normal livers and hearts, and form-C mRNA was preferentially found in normal hearts and peroxisome-induced livers. Analysis of two overlapping genomic clones for the rat ACS gene revealed that the three 5'-untranslated regions of the mRNAs are individually encoded by three different exons located within a 20-kilobase genomic fragment. The transcription start sites of the three forms of ACS mRNA were determined and nucleotide sequences of 5'-upstream regions of the three 5'-end exons were determined. The 5'-upstream regions were fused to the chloramphenicol acetyltransferase gene and transcription units of the three forms of ACS mRNAs were determined. These data indicate that the three forms of ACS mRNA with 5'-end heterogeneity are generated by alternative transcription from three promoters in the rat ACS gene.

Caffeine rapidly decreases potassium conductance of dissociated outer hair cells of guinea-pig cochlea

The effects of caffeine on the outer hair cells (OHCs) freshly dissociated from guinea-pig cochlea were investigated with the whole-cell patch-clamp technique, in both the conventional and the nystatin perforated patch-clamp configurations under voltage-clamp condition. Application of caffeine (> 1 mM for 10-30 s) induced an inward current (Icaffeine) with decrease of conductance in a dose-dependent manner at a holding potential (VH) of -60 mV. The reversal potential of Icaffeine (Ecaffeine) was close to the K+ equilibrium potential. The Icaffeine was not affected by Ca(2+)-free external solution. The internal perfusion of the Ca2+ chelator BAPTA had no effect on Icaffeine. The Icaffeine was not modulated by the external application of H-8 or staurosporine and by the internal perfusion of GDP-beta S. The amplitude of Icaffeine was the largest at the basal region of OHCs when caffeine was locally applied by the 'puffer' method. These results suggest that caffeine induces a decrease in membrane potassium conductance of the OHCs mainly at the basal region without mediating the intracellular signaling pathway.

Focal adhesion kinase is not essential for in vitro and in vivo differentiation of ES cells

Focal adhesion kinase, FAK, is a unique protein tyrosine kinase found in cellular focal adhesions. It is widely expressed and highly phosphorylated during embryogenesis. To examine the function of FAK in cell differentiation, we made FAK-deficient embryonic stem (ES) cells by homologous recombination. However, FAK-deficiency did not interfere with differentiation of the ES cells into cells of three germ layers when implanted subcutaneously into nude mice or when treated with retinoic acid in vitro, nor was there any evidence of defects in hematopoiesis in vitro.

[Alginate gel beads for chemoembolization: initial report]

Alginate gel beads (AGB) were studied as a new material for chemoembolization therapy. AGB were quickly produced by dripping a sodium alginate solution through a cannula into a calcium chloride solution, with bead size controlled by cannular size. AGB containing adriamycin or contrast medium were produced from the corresponding mixture. Sixty percent of adriamycin was eluted from AGB within one hour and 90% within 24 hours, while 95% of iopamidol was eluted in 30 minutes. AGB released these contents slower than gelatin sponge particles. Four dogs underwent transcatheter hepatic arterial embolization with AGB. Normal daily activity was recorded until sacrifice on the fourteenth day. There was no hepatic infarction in those embolized with AGB of 0.5 to 1.0 mm in diameter. Partial liver infarction was found in one with compelled embolization and in two with fragile beads. These observations suggested that AGB constitute an instantly preparable embolic material with slow-release activity and flexible solidity.

[Domestic infection of neurocysticercosis in a Japanese woman, who had not travelled overseas]

A 52-year-old Japanese woman was found to have a single parenchymal cystic lesion in the operculum of the left frontal lobe. Although she had not travelled overseas, neuroradiological and serological studies supported the diagnosis of neurocysticercosis. Three months after a trial with praziquantel, although the cystic lesion decreased in size on MR imagings, she suddenly developed motor dominant aphasia as a manifestation of epileptic attack. This appears to have followed the death of the cysticercus, releasing the cysticercus contents into the surrounding brain and to have stimulated an intense reactive inflammation. Neurocysticercosis, although rare in Japan, may be positively identified by neuroimaging and serological studies and can be treated conservatively with praziquantel.

Relation between markers for viral hepatitis and clinical features of Japanese patients with hepatocellular carcinoma: possible role of alcohol in promoting carcinogenesis

To assess the relationship between hepatitis virus markers and the clinical features of hepatocellular carcinoma (HCC), we measured markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in 88 Japanese patients with HCC. Twelve (14%) patients were HBsAg-positive and 67 (76%) were anti-HCV-positive (both c100-3 and c11/c7). HCV-RNA was detected in 8 (38%) of the 21 anti-HCV-negative patients by PCR, so that 75 patients (85%) were infected with HCV. Of the HBsAg-negative patients infected with HCV with no history of blood transfusion, the mean age of the alcoholics (consumption > 80 g ethanol daily for at least 10 years) was lower than that of the non-alcoholics (60 years vs. 65 years, P < 0.05). Among the HBsAg-negative and anti-HCV (or HCV-RNA)-positive patients with a history of blood transfusion, the mean interval between the time of blood transfusion and the diagnosis of HCC in the alcoholics was shorter (21 years) than that in the nonalcoholics (27 years), but the difference was not statistically significant. We conclude that infection by both HCV and HBV may play a role in the development of HCC, and that alcohol consumption may promote carcinogenesis.

Identification of a novel phospholipase C family gene at chromosome 2q33 that is homozygously deleted in human small cell lung carcinoma

Since a considerably high incidence of allelic loss on chromosome 2q was detected in lung carcinoma and a homozygous deletion at chromosome 2q33 was detected in a small cell lung carcinoma cell line, NCI-H82, a novel tumor suppressor gene has been suggested to be present in this chromosomal region. In the present study, we constructed a cosmid contig map covering the homozygous deleted region, which was estimated as being 220 kbp in size, and identified a gene from the deleted region. All of the coding exons of this gene were homozygously deleted in this cell line, while a 5'-non-coding exons was retained. Since the gene encodes a protein with striking similarity to several members of a family of phospholipase C, we designated this gene as PLC-L (phospholipase C-deleted in lung carcinoma). The PLC-L gene was expressed in a variety of fetal and adult organs including the lung. However, its expression was greatly reduced in seven of 13 (53.8%) of small cell lung carcinoma and 13 of 15 (86.7%) of non-small cell lung carcinoma cell lines. Since its homology to phospholipase C genes suggests the involvement of the PLC-L gene in inositol phospholipid-based intracellular signaling cascade, it is possible that aberrant expression of the PLC-L gene contributes to the genesis or progression of human lung carcinoma.

[A case of inclusion body myositis (IBM) associated with lipid-storage vacuoles]

A 62-year-old woman, who has had slowly progressive muscle weakness and wasting of the four limbs for past 10 years, was evaluated by muscle biopsies; i.e. the deltoid, a moderately atrophic muscle, and the quadriceps femoris, a muscle that was only mildly involved. The specimen from the deltoid disclosed the basic muscle structures having been collapsed, containing many fibers undergoing degeneration. There were rimmed vacuoles and infiltration of macrophages and round cells into the muscle fibers and perimysial space. Inclusion bodies containing fibrillary structures were identified in sarcolemmal nuclei by electron microscopy. When the quadriceps femoris muscle was examined, however, a large number of vacuoles were interspersed between myofibrils that contained numerous lipid droplets. There were no pathological changes suggestive of IBM in this specimen. The case described here is unique in that the muscle biopsies from two separate muscle revealed a distinctly different pathology. Although we were unable to determine the cause of lipid-storage in this case, it is our impression that inclusion body myositis is not a uniform disorder but the characteristic pathology to this particular myositis might be an ultimate feature of several diverse degenerative and/or inflammatory muscle disorders.

Spontaneous resolution of symptoms in an infant with a congenital dural caroticocavernous fistula

We report a 5-week-old boy with a congenital dural caroticocavernous fistula (CCF). He had gradually progressive proptosis, dilated conjunctival veins, chemosis, abducens nerve palsy and an objective bruit. Angiography of the right common carotid artery revealed fistulous communication in the cavernous sinus (CS) region. The CS was fed by the middle meningeal artery and drained through the superior ophthalmic vein and the superior petrosal vein. The child's symptoms and signs disappeared within a few weeks and did not recur over 11 months. At that time, however, angiography still showed a small communication between the right external carotid artery and the CS.

[Role of autoantibody in preeclampsia]

The role of anti-ssDNA and dsDNA antibody in preeclampsia were studied. Serum samples were taken from 38 pregnants with preeclampsia including 19 cases of severe type. Also, 26 normal pregnant women were studied as the control. Anti-ssDNA and dsDNA antibody were measured by enzyme-linked immunosorbent assay (ELISA). Anti-phospholipid antibody (APA), was measured by ELISA. Anti-dsDNA antibody was positive in 1 of the 38 preeclampsia. Anti-ssDNA antibody was positive in 15 out of the 38 cases (39.4%) in preeclampsia. Incidence of anti-ssDNA positive preeclampsia is related to it's severity of symptom as following: Six of 19 mild preeclampsia (26.3%) were positive. In severe cases, 10 of 19 (52.6%). However, the relationship between anti-ssDNA antibody and IUGR in preeclampsia, was not confirmed, although the antiphospholipid antibody was related to the IUGR. From these results, we concluded that the autoantibody, such as anti-DNA antibody, might be produced in preeclampsia and the B cell activation might play a role of exaggeration of preeclampsia.

Emergence of tetracycline resistance due to a multiple drug resistance plasmid in Vibrio cholerae O139

Of the 173 clinical strains of Vibrio cholerae O139 isolated from India, Bangladesh, and Thailand tested, six strains from India were resistant to tetracycline, ampicillin, chloramphenicol, kanamycin, and gentamicin. These six strains harbored a self-transmissible plasmid that mediated resistance to tetracycline, ampicillin, chloramphenicol, kanamycin, gentamicin, sulfamethoxazole, trimethoprim, and O/129. The multiple drug resistance plasmids were 200 kb in size and belonged to the incompatibility group C. Although a majority of the O139 strains (94.8%) were highly resistant to streptomycin, sulfamethoxazole, trimethoprim, and O/129, the tetracycline-susceptible strains so far tested were plasmid-negative. The data suggest the existence of two distinct multiple antimicrobial agent resistance (MAR) patterns in V. cholerae O139.