Aseptic meningo-radiculo-encephalitis presenting initially with urinary retention: a variant of acute disseminated encephalomyelitis

We report three male patients with aseptic meningoencephalo- radiculitis presenting with acute urinary retention. Viral antibody titers for herpes types I and II and the PCR studies were negative. The cerebrospinal fluid revealed elevated myelin basic protein. The serum antibodies against a panel of gangliosides, some of which are known to be associated with acquired demyelinating neuropathies, were all negative. The magnetic resonance imaging (MRI) studies revealed spotty T2 high intensities in the basal ganglia, thalamus and brainstem in two patients. In one patient,meningeal gadolinium enhancement of the conus and cauda equina of the spinal cord was recognized. On urodynamic studies, all patients showed features of atonic bladder with or without detrusor hyperactivity. They were treated conservatively without using steroids or immunoglobulins, and made a remarkable functional recovery with the disappearance of abnormal MRI findings.However, all three were left with erectile dysfunction, and two continued to use self-intermittent catheterization at more than 3-year follow-up. There was no recurrence of symptoms. The underlying causes remain unclear, though they may represent a variant of acute disseminated encephalomyelitis.

4-(Methylthio)-3-butenyl isothiocyanate, a principal antimutagen in daikon (Raphanus sativus; Japanese white radish)

The antimutagenic activity of n-hexane extracts from eight strains of daikon (Raphanus sativus; Japanese white radish) have been examined using the UV-induced mutation assay of Escherichia coli B/r WP2. A correlation was found between the potency of antimutagenicity and the amount of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) in their n-hexane extracts. Because the pure MTBITC also showed antimutagenicity, MTBITC is presumably the active antimutagen principle in n-hexane extracts of daikon. Among the eight strains of daikon studied, Aokubi, the improved common strain in Japan, contained 71.0 micromol of MTBITC in 100 g of fresh daikon. In contrast, Karami and Momoyama, which are original wild strains, contained much more MTBITC (363.5 and 168.0 micromol/100 g, respectively). In addition, phenethyl isothiocyanate was found in a lesser amount (5-33 nmol/100 g) in eight strains of daikon, and allyl isothiocyanate and benzyl isothiocyanate were not detectable in any strains (<3 nmol/100 g). The amount of total isothiocyanate in grated daikon was 7.0 times higher than that in cut daikon measured after 30 min of cooking. Through eating habits, humans might be able to consume substantial amounts of the antimutagen MTBITC from dishes using the grated form of wild strains of daikon. Therefore, it is possible to substantially increase the intake of the antimutagenic ingredient of daikon (i.e., MTBITC) by changing food preferences and preparation procedures (i.e., using the grated form of the wild strains).

Autocrine induction of gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) and GLS-induced expression of matrix metalloproteinases in rheumatoid arthritis synoviocytes

OBJECTIVE

The purpose of this study was to examine how gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) is involved in the molecular mechanism of cartilage degradation in rheumatoid arthritis (RA) with special reference to the GLS-induced gene expression and protein synthesis of matrix metalloproteinase (MMP)-1 (collagenase-1) and MMP-3 (stromelysin-1).

METHODS

Fibroblast-like synoviocytes (FLSs) obtained from RA patients were cultured and stimulated by GLS. Changes in the expression levels of GLS, MMP-1 and MMP-3 were assessed by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) for GLS, and by RT-PCR and enzyme-linked immunosorbent assay for MMPs and tissue inhibitor of metalloproteinase 1.

RESULTS

GLS demonstrated a self-induction of mRNA in cultured RA FLSs. GLS evoked a dose-dependent induction of MMP-1 and MMP-3 mRNAs, and subsequently their extracellular secretion.

CONCLUSION

These findings suggest that GLS is a plausible pathogenic factor causing the extensive joint destruction in RA mediated via MMPs.

Detection of serum anticerebellar antibodies in patients with Miller Fisher syndrome

We performed Western blot analysis to detect anticerebellar antibodies in the serum of patients with Miller Fisher syndrome (MFS). We studied 7 MFS patients, 6 Guillain-Barré syndrome (GBS) patients and 10 normal healthy persons as controls. Six MFS patients (86%) had IgG antibodies against mouse cerebellar protein, whereas 3 GBS patients (50%) and 4 healthy controls (40%) had antibodies. The mean number of antibodies in the serum of patient with MFS was 2.43, which was significantly more than that of GBS patients (mean 0.67) and healthy control (mean 0.70). This finding suggests variability and complexity of target in nervous systems that suffer aberrant immunity in MFS, and may also reflect the variability and heterogeneity of the pathogenesis of this syndrome.

Expression and potential role of inducible nitric oxide synthase in the central nervous system of Theiler's murine encephalomyelitis virus-induced demyelinating disease

Intracerebral inoculation of susceptible strains of mice with Theiler's murine encephalomyelitis virus (TMEV) results in immune-mediated demyelinating disease. We examined the pathogenic roles of nitric oxide (NO) and inducible NO synthase (iNOS) in TMEV-induced demyelinating disease (TMEV-IDD). The presence of iNOS was confirmed in the spinal cords of TMEV-infected mice using immunohistochemical staining with anti-iNOS antibody on day 0 (control) and days 15, 30, 60, and 120. Aminoguanidine (AG), a specific inhibitor of iNOS, was injected intraperitoneally (ip) on 1, 3, 5, 8, 10, and 12 days post-TMEV inoculation as induction phase or 15, 17, 19, 22, 24, and 26 days as effector phase. Control animals in each experiment received phosphate-buffered saline (PBS) ip at similar time intervals. Few iNOS-positive cells were observed in the spinal cords of naive SJL/J mice. In the early phase (day 15) of TMEV-IDD, an increase of iNOS-positive cells was detected in the leptomeninges and perivascular space of the spinal cords. The number of iNOS-positive cells was increased and reached its peak on day 60, when histology of the animals showed peak infiltration with inflammatory cells. The clinical course of TMEV-IDD on each day postintracerebral infection was significantly reduced in mice treated with AG in the effector phase, and there was no significant difference between mice treated with AG in induction phase versus those administered PBS. Thus, NO production via iNOS appears to be a pathogenic factor in the effector phase of TMEV-IDD.

[Two cases with chronic inflammatory demyelinating polyneuropathy showing high signal and enlargement of the brachial plexus in short TI inversion recovery of MRI]

We reported valuable MRI findings of the brachial plexus seen in two cases with chronic inflammatory demyelinating polyneuropathy (CIDP). Case 1 was a 44-year-old man who developed slowly progressive weakness and atrophy of the extremities with no sensory disturbances. Studies of CSF showed a normal level of protein and no increase of cell counts but nerve conduction studies demonstrated a significant conduction block between the axilla and the elbow in the right ulnar nerve. Case 2 was a 34-year-old male who had been suffering from distal limb weakness and sensory disturbance. Protein content in CSF was markedly elevated without pleocytosis, and nerve conduction studies revealed a conduction block between the elbow and the wrist in the right ulnar nerve. He received corticosteroid therapy, resulting in a good recovery. Brachial plexus in both cases showed enlargement with marked high signal on short TI inversion recovery (STIR) of MRI. STIR is a fat suppressed T2 weighted image and this technique is known to be useful to identify the morphology of peripheral nerve tissues. CIDP is one form of hypertrophic neuritis and the MRI findings seen in these two cases strongly support the diagnosis of CIDP.

Prominent effect of immunoadsorption plasmapheresis therapy in a patient with chronic inflammatory demyelinating polyneuropathy associated with hepatitis B infection

We encountered a patient with chronic inflammatory demyelinating polyneuropathy associated with hepatitis B infection. Immunohistochemical study revealed the deposition of immune complex composed of hepatitis B surface antigen (HBsAg) both around the endoneural capillary and in the endoneurium. Neurological signs were significantly improved by immunoadsorption plasmapheresis (IAPP) treatment without incorporating corticosteroid hormone therapy; weekly long-term IAPP has successfully maintained the patient's condition.

Kinetic analysis of the disposition of MRK16, an anti-P-glycoprotein monoclonal antibody, in tumors: comparison between in vitro and in vivo disposition

The kinetics of the disposition of MRK16, an anti-P-glycoprotein monoclonal antibody, was studied in two human colorectal tumor cell lines, HCT-15 and COLO205, whose P-glycoprotein expression is extensive and poor, respectively. In a series of in vitro binding studies, the amount of MRK16 associated with HCT-15 cells at steady state was approximately 40 times greater than that associated with COLO205 cells. In in vivo studies, the disposition of MRK16 was determined in tumor-bearing mice after intravenous administration. The difference in the tumor-to-plasma concentration ratio between the two cell lines was only 2.3-fold at 72 hr after injection. To explain the large difference observed between the in vitro and in vivo results, a series of kinetic simulation studies were performed. By considering the physiological parameters specific for MRK16 (such as permeability-surface area product and the kinetic parameters determined in vitro), the time profiles for the tumor concentration were predicted. The predicted difference in the tumor-to-plasma concentration ratio at 72 hr was calculated to be 2.6-fold, although the permeability-surface area product across the tumor capillary and other physiological parameters were comparable between the two tumor cell lines. The discrepancy between the in vitro and in vivo results was accounted for by the fact that the tumor extracellular fluid concentration at this time point was 13-fold lower in HCT-15 tumors than in COLO205 tumors because of the restricted penetration of MRK16 through the tumor capillaries. This finding suggests that this factor accounts for the in vitro and in vivo difference in the tumor disposition of MRK16.

A study on a new antineural antibody in a case of paraneoplastic sensory neuropathy associated with breast carcinoma

Paraneoplastic sensory neuropathy is a remote effect of cancer, usually associated with small cell lung carcinoma and anti-Hu antibody. This report details the case of a 59 year old woman with a breast carcinoma and a paraneoplastic sensory neuropathy characterised by chronic asymmetric sensory neuropathy. Anti-Hu antibody was not detected in her serum; nor were other known antineuronal antibodies such as anti-Ri and Yo. However, we have found an antineural antibody that reacted to a 106 kDa mouse neural antigen which has not yet been reported. Immunohistochemically, this antineural antibody bound to the posterior grey horn. This finding suggests that this antineural antibody may play an important part in the pathogenesis of the sensory neuropathy of this patient.

Tumor necrosis factor-alpha and transforming growth factor-beta production by isolated mononuclear cells from the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis

We demonstrated time course of the number of mononuclear cells (MNCs) isolated from spinal cords (SCs) correlates with the degree of experimental autoimmune encephalomyelitis (EAE) of Lewis rats, and analyzed their tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta production by MNCs, using enzyme-linked immuno sorbent assay and enzyme-linked immuno spot (ELISPOT) assay. The number of MNCs varied from 5 to 620 x 10(4) per SC of normal Lewis rat and Lewis rat with EAE. MNCs increased and reached a peak on day 2 post clinical onset (Day 2), and subsequently declined through the clinical course. The increase of infiltrating MNCs in SCs paralleled the severity of the disease development. TGF-beta 1 in plasma of rats with EAE significantly increased on Day 1 and reached the peak on Day 3. TNF-alpha levels in culture supernatants of MNCs from SCs increased on Day 1, and it decreased from Day 2, and declined on Day 4 when animals began to recover. TGF-beta 1 was not detected in culture supernatant during the whole clinical course. The number of TNF-alpha and TGF-beta 1 producing cells that were detected by ELISPOT assay increased on Day 0, and decreased rapidly after the onset of neurological symptoms. Thus, increase of TNF-alpha appeared in the early phase of the disease and then promptly decreased. In contrast, TGF-beta 1 was activated during the later recovering phase of the disease. We consider that TNF-alpha may play an important role in the pathogenesis of EAE and TGF-beta may inhibit the development of EAE.

Monoclonal antibodies specific for P-glycoprotein

Multidrug resistance (MDR) is one of the major obstacles to successful cancer chemotherapy. Since P-glycoprotein (P-gp) encoded by the MDR-1 gene plays a key role in MDR, many P-gp-specific monoclonal antibodies (MAbs) have been generated for characterization and analysis of P-gp. Among those antibodies, MRK16 has been widely used not only for elucidation of the mechanisms of P-gp-mediated MDR but also for diagnostic and therapeutic studies. Two types of magnetic cell sorting assays, termed MRK16-MACS and MRK16-MACS-FACS, have been established by us and may offer a useful tool to quantitate low levels of P-gp expression. This article describes the characteristics of the antibodies against P-gp and discuss the diagnostic implications of the antibodies.

Establishment and evaluation of MRK16-magnetic cell sorting assays for detecting low expression of multidrug resistance P-glycoprotein using human leukemia cell lines and peripheral blood cells from healthy donors

Two types of magnetic cell sorting assays, termed MRK16-MACS and MRK16-MACS-FACS, have been established to detect low expression level of P-glycoprotein (P-gp) using a monoclonal antibody MRK16, which recognizes a cell surface epitope of P-gp. With K-562 and U-937 cell lines, which are known to express low levels of P-gp and hence routinely used as negative control cell lines in conventional flow cytometry, both assays gave significantly positive reactivities indicating improved specificity and sensitivity of these assays. The findings in the dilution test, where P-gp-positive cells were added to P-gp-negative cells at various ratios, demonstrated that the MRK16-MACS assay is quantitative and capable of detecting small numbers of P-gp-positive cells as few as 2.5% of the total cells tested. Furthermore, specific enrichment of P-gp-expressing cells in magnetic cell sorting assays was verified by reverse transcription-polymerase chain reaction (RT-PCR) analysis and functional assay for P-gp with Rhodamine 123. The availability of such magnetic cell sorting assays may offer an approach to quantitate low level of P-gp expression.

[The detection of anti-cerebellar antibody western blot analysis in serum from a patient with Miller Fisher syndrome]

We here report a case of Miller Fisher syndrome (MFS) in which serum anti-cerebellar antibody was detected by Western blot analysis. The 32-year-old male studied suffered from diplopia, gait ataxia and sensory disturbance in the distal portion of the upper limbs preceded by cold-like symptoms. Neurological examination on admission revealed that he had external ophthalmoplegia with bilateral ptosis, cerebellar ataxia and areflexia. A cerebrospinal fluid examination showed albuminocytologic dissociation with a protein concentration of 60 mg/dl. Brain CT and MRI showed no significant abnormalities. The patient was diagnosed as MFS, and treated it with two sessions of immunoadsorption plasmapheresis (IAPP). After receiving IAPP therapy, the patient's neurological symptoms and signs were improved. Western blot analysis showed the existence of antibody directed against mouse cerebellum but not against mouse cerebrum, brain stem, and spinal cord in his serum, the level of which was decreased after the IAPP therapy. Serum anti-GQ1b antibody was also elevated. As far as we are aware, there have been no reports showing the existence of anti-cerebellar antibodies detected by Western blot analysis. Though the pathogenesis of MFS remains unclear, our findings suggest that anti-cerebellar antibody detected by Western blot analysis may be caused by cerebellar ataxia in MFS.

[Characterization of infiltrating mononuclear cells in the spinal cords of Lewis rats with experimental autoimmune encephalomyelitis (EAE)]

Mononuclear cells (MNCs) infiltrating in spinal cords (SCs) of Lewis rats with EAE were isolated in order to permit flow cytometric (FCM) analysis of these cell populations, using monoclonal antibody to T cell, CD4, CD8. MHC class II antigen (Ia), intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1). The number of MNCs isolated from SC varied from 5 to 620 x 10(4). They were increased and reached a peak on day 2 post clinical onset, and subsequently declined through the clinical course. The increase of infiltrating cells in SC paralleled the severity of the disease development. The surface phenotypes of MNCs from rats on the day of clinical onset were determined by flow cytometry. The phenotypes found in these rats were as follows: T cells (70.3%); CD4 + (58.3%); CD8 + (40.3%); Ia (51.9%); ICAM-1 (62.6%); LFA-1 (75.8%). These findings suggest that high proportion of ICMA-1 and LFA-1 expression may be important in antigen presentation in the inflammatory lesions of SC and in promoting lymphocyte extravasation across the blood-brain barrier during the disease. The approach we employed offered more sophisticated and quantitative analysis of CNS inflammatory cells, which is unobtainable by tissue section staining.

[A study on subpopulation of helper T cells in chronic inflammatory demyelinating polyneuropathy]

Chronic inflammatory demyelinating polyneuropathy (CIDP) is thought to be an inflammatory autoimmune disease against peripheral myelin. Recently several animal models have suggested that preferential activation of Th1 cell response is central to the pathogenesis of this disease. We studied the function of CD4 positive T cell subsets, Th1 cells and Th2 cells by analyzing their representative secreting cytokines. Th1 cells secrete Interferon gamma (IFH gamma) and Th2 cells secrete Interleukin 4 (IL4). Using enzyme linked immunospot (ELISPOT) assay, a very sensitive single cell analysis system, we enumerated IFN gamma and IL4 secreting peripheral blood lymphocytes in patients with CIDP. Also we examined these cytokines in supernatants of cultured peripheral blood lymphocytes by a very sensitive enzyme linked immunosorbent assay (ELISA), Immunodot assay and westernblot assay. In culture supernatants of CIDP patients' peripheral blood lymphocytes, the levels of both IFN gamma and IL4 were higher during the exacerbation stage than the remission stage. In the remission period, though the levels of IFN gamma and IL4 were low in the supernatants, the ELISPOT assay revealed that the number of IL4 secreting cells was elevated compared with that of IFN gamma secreting cells. Our results suggest that the switch from Th1 to Th2 might play an important role in inducing the remission stage in patients with CIDP.

[A pathogenic study of chronic inflammatory demyelinating polyradiculoneuropathy in a patient with hepatitis B infection]

We immunologically examined the pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy in a patient with HB hepatitis. A 41-year-old male clerk has been suffered from muscle weakness, tingling and numbness in the distal portion of all limbs. All symptoms were compatible with the typical patterns of chronic inflammatory demyelinating polyradiculoneuropathy. We examined the patient's serum and biopsied sural nerve, using histochemical and immunological techniques. We detected the band that reacted with anti-HBs antibody in the sural nerve in western blotting. The result indicated that HBs antigen was expressed on the peripheral nerves in the patient. There were no anti-peripheral nerve antibodies neither in the sural nerve or serum. There was no increase of immune complex in the serum. No deposition of immunoglobulins and complements were detected in the sural nerve. Immunoadsorption therapy had no effect on this patient, but administration of prednisolone improved his symptoms drastically. These findings suggest that a cytotoxic T cell may had played a more important role than humoral factors in this patient's nerve injury. Though the pathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy remains unclear, our findings seem to be very interesting in that they go some way toward clarifying the pathogenesis of this disease.

Expression of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in the spinal cord of rats during acute experimental allergic encephalomyelitis

We investigated the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) by cells in the central nervous system (CNS) of Lewis rats during acute experimental allergic encephalomyelitis (EAE). A few endothelial cells in the CNS of normal rats expressed ICAM-1, whereas during the active phase of EAE, ICAM-1 was present on many endothelial cells. This alteration was detectable the day before clinical symptoms. Since histopathological studies showed few detectable mononuclear cells or inflammatory foci in any section of the preclinical rats, the expression of ICMA-1 was considered to be important at least in the early stage of inflammation. LFA-1 was seen on perivascular infiltrating cells. An increase in either ICAM-1- or LFA-1-positive cells was initially seen in the lumbosacral portion of the spinal cord, which then extended to the thoracic portion. The number of either ICAM-1- or LFA-1-positive cells peaked on the day of clinical onset in the lumbosacral portion. In contrast, in the thoracic portion, a peak in the number of either ICAM-1- or LFA-1-positive cells was observed on the day after clinical onset. This ascending extension of either ICAM-1- or LFA-1-positive cells was correlated with the progression of neurologic signs. It is suggested that increased expression of ICAM-1 and LFA-1 in the CNS of rat EAE may promote the extravasation of lymphocytes across the blood-brain barrier and be related to progression of the disease.

Specific targeting and killing activities of anti-P-glycoprotein monoclonal antibody MRK16 directed against intrinsically multidrug-resistant human colorectal carcinoma cell lines in the nude mouse model

Anti-P-glycoprotein (P-gp) monoclonal antibody, MRK16, and its F(ab')2 fragment were evaluated for its therapeutic efficacy to P-gp-mediated multidrug resistant human colorectal carcinoma cell lines in a nude mouse model. In a blood clearance experiment, 125I-labeled MRK16 had a half-life (16 h) 7 times longer than its F(ab')2 fragment (half-life of 1.8 h) in circulation in nude mice, and approximately 16 and 5% of MRK16 were retained on days 10 and 20 after injection, respectively. In biodistribution experiments using nude mice bearing HCT-15, an intrinsically resistant cell line, 125I-labeled MRK16 accumulated at the tumor site significantly higher than its F(ab')2 fragment as revealed by the percentage of injected dose/g of tissue values (7.4 versus 0.6%) on day 3 after injection. In contrast, the tissue to blood ratio at the tumor site of the MRK16 was significantly lower than that of its F(ab')2 fragment (1.2 versus 10.5). Specific targeting of the MRK16 F(ab')2 fragment to the P-gp-positive tumor (HCT-15) but not to the P-gp-negative tumor (COLO 205) was observed in the nude mice bearing both tumors. In the therapeutic efficacy tests, when administered i.v. 3 times on days 1, 4, and 7 after tumor s.c. inoculation, MRK16 alone showed the significant inhibition of tumor growth of P-gp-positive cell lines, HCT-15, DLD-1, SW480, and SW1417 in contrast to cases of P-gp-negative cell lines, COLO 205 and KM20L2. This inhibitory effect of MRK16 was enhanced in combination with Adriamycin, which alone hardly inhibited the tumor growth. However, MRK16 F(ab')2 fragment alone, even at 1 mg/mouse, had little inhibitory effect on the growth of HCT-15 in the same treatment schedule. When administered at early palpable stage, the degree of HCT-15 tumor growth suppression depended on the number of MRK16 injections. At more progressed stages, treatment with MRK16 alone showed little antitumor activity but when combined with Adriamycin resulted in significant suppression of tumor growth. The present results suggest that MRK16 may be useful for in vivo immunoscintigraphy and immunotherapy of multidrug-resistant colorectal carcinoma.

[Hemodynamic situation immediately after cardiopulmonary bypass in cases of coronary artery bypass grafting (CABG) using both bilateral internal thoracic arteries (ITAs) and right gastroepiploic artery (GEA)]

Hemodynamic situation immediately after cardiopulmonary bypass was studied in cases of CABG using bilateral ITAs and right GEA. Though cardiac output was kept greater than 4.0 l/min, the blood pressure soon after weaning from cardiopulmonary bypass was low in patients who necessitated further circulatory assist, intraaortic balloon pumping (IABP) and/or additional surgical bypass procedure. In cases of CABG using arterial grafts and no vein graft, the perfusion pressure is most important to stabilize the hemodynamic status because low pressure may provoke peripheral vasoconstriction resulting in spastic reaction of the ITA and GEA. These arterial grafts seemed to keep the characteristics as the peripheral artery. Some papers pointed out less flow capacity of arterial grafts compared with that of saphenous vein graft, but CABG with arterial grafts alone was safe clinically if care is taken for keeping the perfusion pressure as high as preoperatively.

[A case of B-cell lymphoma with clinical and histological features of malignant histiocytosis]

A case of B cell lymphoma with clinical and histological features of malignant histiocytosis was described. A 57-year-old male was admitted to Shinshu University Hospital because of transverse myelopathy. Five months before admission, he noticed urinary disturbance, which progressed to urinary obstruction. The following month, bilateral muscular weakness appeared in his legs. A few days later he could not stand up, and was admitted to a local hospital. Neurological examination revealed sensory disturbances below the level of Th12 in all modalities, and marked weakness and hyperreflexia in the lower limbs. A spinal tumor was suspected. However, myelography showed no abnormality. The patient's condition worsened and he became bed-ridden in February 1990. He was transferred to Shinshu University Hospital for further evaluation. On admission he was poorly nourished with fever, anemia, hepatomegaly, and bilateral pretibial pitting edema. No lymphadenopathy was observed. Neurological examination showed total sensory loss below the level of Th12, spastic paraplegia, hyperreflexia in the legs, and urinary obstruction. Laboratory findings revealed an elevated erythrocyte sedimentation rate, increased CRP, pancytopenia, and hypoalbuminemia. Serum level of IgG, IgA, IgM, LDH, ALP, GPT and total bilirubin were increased. CSF and MRI imaging of the spinal cord were normal. Proliferation of atypical histiocytes with marked erythrophagocytosis, which is a characteristic pathological feature of malignant histiocytosis, was observed in peripheral blood and aspirated bone marrow. Immunoenzyme staining of bone marrow using monoclonal antibody L-26, which is a B-cell marker, revealed B-cell lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of an etoposide-resistant human K562 cell line, K/eto

An etoposide-resistant K562 cell line (K/eto) was obtained by stepwise exposure, in culture, to increasing concentrations of etoposide, without the use of mutagens. This cell line was resistant to etoposide, and slightly resistant to adriamycin, but sensitive to anti-cancer drugs such as camptothecin, vincristine, actinomycin D and so on. P-Glycoprotein, the mdr1 gene product, was not detected in this cell line, as assessed by immunocytochemistry, immunoprecipitation and flow cytometry. Overexpression of mdr1 mRNA was also not found. Interestingly, expression of 85 kD protein recognized by MRK 20 monoclonal antibody was noted. The level of DNA topoisomerase II protein, detected by antibody staining, decreased concomitantly with a general decrease in DNA topoisomerase II unknotting activity, while DNA topoisomerase I activity was not affected. Cellular accumulation of [3H]etoposide was reduced by 75% in the resistant line compared with parental K562. Karyotype analysis showed that the number of chromosomes in K/eto was 55 and neither a homogeneous staining region nor double-minute chromosomes were detected. These results indicate that this resistance is not due to an altered interaction between the drug and cellular transport machinery, i.e. MDR1, associated with the "classic" multiple drug resistance phenotype, but rather is due to the existence of other mechanism(s) of resistance, decreased transport of the drug and decreased target enzyme, DNA topoisomerase II.

Establishment of multidrug resistant human colorectal carcinoma HCT-15 cell lines and their properties

A series of MDR cell lines with various levels of P-glycoprotein have been established from a human colorectal carcinoma cell line, HCT-15, by stepwise exposure to adriamycin. The relative drug resistance of these cell lines correlated directly with both MDR1 mRNA levels and P-glycoprotein expression levels. Intracellular accumulation of adriamycin decreased inversely to their resistance. Drug sensitivities of these lines were reversed using verapamil. Since these cell lines are transplantable to nude mice, they may provide a useful animal model of MDR solid tumors for therapeutic experiments.