HIV-1-specific cell-mediated immunity is enhanced by co-inoculation of TCA3 expression plasmid with DNA vaccine

We developed a candidate DNA vaccine designated pCMV160IIIB with pcREV (pCMV160IIIB/REV) that encodes gp160 of human immunodeficiency virus (HIV)-1IIIB and Rev driven by the cytomegalovirus (CMV) promotor. This vaccine induced both HIV-1-specific antibodies and cytotoxic T lymphocyte (CTL) activity. In the present study, we inoculated the TCA3 expression plasmid into mouse skeletal muscle with pCMV160IIIB/REV to determine whether this cytokine expression plasmid was able to modify the immune response. Results of a delayed-type hypersensitivity (DTH) assay using footpad swelling as well as those of a CTL assay clearly demonstrated that cell-mediated immunity (CMI) elicited by co-inoculation of pCMV160IIIB/REV with the TCA3 expression plasmid was markedly enhanced compared with that obtained using pCMV160IIIB/REV alone. When TCA3 expression plasmid was inoculated with anti-TCA3 antibody, enhancement of the DTH response was suppressed below the level of that obtained with pCMV160IIIB/REV alone. The titre of HIV-1-specific IgG2a was slightly high when pCMV160IIIB/REV was co-inoculated with this plasmid, suggesting that T-helper 1 (Th1) response was predominant in TCA3-inoculated mice. Infiltration of mononuclear cells was seen in the muscles at sites where TCA3 expression plasmid had been inoculated. Our present data suggest that TCA3 expression plasmid has potent adjuvant activity that results in an augmented CMI response.

[Clinical study on a concomitant therapy with fluconazole and human recombinant granulocyte colony stimulating factor in the treatment of systemic fungal infections with hematological disorders]

The clinical efficacy and the safety of concomitant therapy with fluconazole and recombinant human granulocyte colony stimulating factor (rhG-CSF) was compared with fluconazole monotherapy in neutropenic patients with hematological disorders. The clinical efficacy rate was 73.5% (25/34) in the combination therapy and 48.1% (37/77) in monotherapy. The difference between the two is statistically significant. Side effects were not observed in the combination group, but laboratory abnormalities were found in 6 patients with an incident rate of 11%. The combination therapy with fluconazole and rhG-CSF may be selected as empiric therapy for systemic fungal infection associated with hematological disorders, since this combination therapy showed high efficacy and low incident of side effects. Some patients, however, did not show increased neutrophil counts in spite of rhG-CSF administration.

Effect of recombinant human granulocyte colony-stimulating factor on combination therapy with aztreonam and clindamycin for infections in neutropenic patients with hematologic diseases

The present multicenter study was performed to evaluate the effect of recombinant human granulocyte-colony stimulating factor (rhG-CSF) on combination therapy using aztreonam (AZT) and clindamycin (CLDM) to treat severe infection in neutropenic patients with hematologic diseases. Forty-three neutropenic patients with infections (rhG-CSF group) were treated with AZT (2 g) and CLDM (600 mg) 2-3 times daily as well as rhG-CSF (Lenograstim or Filgrastim: 2-5 mu/kg/day). The clinical efficacy of this regimen was compared to that obtained in 44 febrile neutropenic patients, with hematologic diseases, who received only AZT and CLDM in a previous study (historical control group). The overall efficacy rate was 69.8% (30/43) in the rhG-CSF group and 65.9% (29/44) in the historical control group. Although the neutrophil count was significantly increased and C-reactive protein tended to be lower in the rhG-CSF group, the daily maximum body temperature profiles of the 2 groups were nearly the same. These results suggest that rhG-CSF is of little benefit in the treatment of single infectious episodes in neutropenic patients, and that appropriate antibiotic therapy is more important.

Cloning of the cDNA encoding mouse PP5/TFPI-2 and mapping of the gene to chromosome 6

Placental protein 5 (PP5)/tissue factor pathway inhibitor-2 (TFPI-2) is a new homologue of TFPI, which contains three tandemly repeated Kunitz-type proteinase inhibitory (KPI) domains and potently inhibits the extrinsic blood coagulation cascade. In this study, mouse PP5/TFPI-2 cDNA was cloned using a human PP5/TFPI2 cDNA fragment as a probe. The characteristic three KPI domains with short spacer sequences and a basic amino acid stretch in the carboxyl-terminal region present in human PP5/TFPI-2 were well conserved in mouse PP5/TFPI-2. In general, the P1 reactive site residues of active KPI domains are basic amino acids. However, the putative P1 residues of the first, second, and third KPI domains were glutamine, aspartic acid, and serine, respectively. Mouse PP5/TFPI-2 mRNA was highly expressed in developing placenta as in humans. Adult liver and kidney also contained a significant amount of its transcripts. The mouse PP5/TFPI-2 gene was found to be located in the R-positive A2 band by the direct R-banding FISH and identified at 2.7 cM proximal to D6Mit 1 by interspecific backcross analysis.

Usefulness of ultrasound-guided, fine-needle aspiration biopsy for palpable breast tumors

OBJECTIVE

To investigate whether ultrasound (US) guidance improves the sensitivity of fine-needle aspiration biopsy (FNAB) in patients with palpable breast tumors.

DESIGN

A retrospective study.

SETTING

A university hospital.

PATIENTS

A total of 107 patients with breast tumors (114 lesions) underwent US-guided FNAB and 138 patients (143 lesions) underwent FNAB guided by palpation (standard FNAB).

MAIN OUTCOME MEASURES

The diagnoses obtained by FNAB were compared with the surgical findings and the diagnostic value of US-guided FNAB was evaluated.

RESULTS

The sensitivity of US-guided FNAB was 89.3%, the specificity was 82.9%, and the accuracy was 86.9%. In contrast, the sensitivity of standard FNAB was 61.1%, the specificity was 73.3%, and the accuracy was 65.0%. For breast tumors 2.0 cm or less in diameter, the sensitivity and accuracy of US-guided FNAB were significantly higher than those of standard FNAB.

CONCLUSION

Ultrasound-guided FNAB can improve the preoperative diagnosis of breast cancer, especially in patients with tumors that are 2 cm or less in diameter.

Contribution of interleukin-3 to antigen-induced Th2 cytokine production

Short-term stimulation of mouse spleen cells in vitro with interleukin (IL)-3 induces the secretion of the Th2 cytokines IL-4 and IL-6. Non-B/non-T cells were the target of this IL-3 effect. However, during long-term antigen-dependent culture, T cells are the major source of IL-4 and IL-6. The addition of IL-3 to such cultures also led to a significant increase in IL-4 and IL-6 production. This Th2 cytokine secretion was amplified by the addition of irradiated non-B/non-T cells at the initiation of culture, and was inhibited by anti-IL-4 antibodies. These findings suggest that IL-3 induces the rapid release of IL-4 and IL-6 by non-B/non-T cells, thereby creating an immune milieu conducive to the development of antigen-specific IL-4 and IL-6-secreting Th2 cells.

High-resolution T2-weighted MR imaging of the inner ear using a long echo-train-length 3D fast spin-echo sequence

The purpose of this study was to assess the value of a long echo-train-length 3D fast spin-echo (3D-FSE) sequence in visualizing the inner ear structures. Ten normal ears and 50 patient ears were imaged on a 1.5T MR unit using a head coil. Axial high-resolution T2-weighted images of the inner ear and the internal auditory canal (IAC) were obtained in 15 min. In normal ears the reliability of the visualization for the inner ear structures was evaluated on original images and the targeted maximum intensity projection (MIP) images of the labyrinth. In ten normal ears, 3D surface display (3D) images were also created and compared with MIP images. On the original images the cochlear aqueduct, the vessels in the vicinity of the IAC, and more than three branches of the cranial nerves were visualized in the IAC in all the ears. The visibility of the endolympathic duct was 80%. On the MIP images the visibility of the three semicircular canals, anterior and posterior ampulla, and of more than two turns of the cochlea was 100%. The MIP images and 3D images were almost comparable. The visibility of the endolymphatic duct was 80% in normal ears and 0% in the affected ears of the patients with Meniere's disease (p < 0.01). In one patient ear a small intracanalicular tumor was depicted clearly. In conclusion, the long echo train length T2-weighted 3D-FSE sequence enables the detailed visualization of the tiny structures of the inner ear and the IAC within a clinically acceptable scan time. Furthermore, obtaining a high contrast between the soft/bony tissue and the cerebrospinal/endolymph/ perilymph fluid would be of significant value in the diagnosis of the pathologic conditions around the labyrinth and the IAC.

Dermatomyositis and malignancy: case report and review of the Japanese literature

The first reported association of dermatomyositis with malignancy was by Stertz in 1916, who described a patient with proximal muscle weakness, eyelid changes, and evidence of myositis on muscle biopsy as well as a coexisting gastric carcinoma. In the same year, Kankeleit described a patient with dermatomyositis and breast cancer--the seeds of a controversy were thus sewn. We report a female patient with multiple cancer who developed dermatomyositis and review the relevant Japanese literature. Our patient suffered from metachronous bilateral breast cancer and thyroid cancer. She underwent curative resection of all 3 tumors. Our experience suggests that clinicians should perform extensive screening of dermatomyositis patients to salvage those with occult cancer, although the issue of cost effectiveness also has to be considered.

Platelet-dependent thrombin generation in patients with diabetes mellitus: effects of glycemic control on coagulability in diabetes

OBJECTIVES

This study sought to assess the usefulness of platelet-dependent thrombin generation as an index of coagulability in diabetes and to determine the effect of glycemic control on coagulability in diabetes.

BACKGROUND

It is important to investigate the interaction of platelets and the coagulation factors to clarify the processes of the coagulation system in detail.

METHODS

Platelet-rich plasma (150 X 10(9)/liter), 0.5 ml, was prepared, and 40 mmol/liter of calcium chloride was added to initiate clotting. S-2238 was added to each sample in a microtiter plate every 10 min, and the absorbance of the released color product at 2 min was measured spectrophotometrically at a wavelength of 405 nm using a microtiter plate reader as thrombin generation. We measured the platelet-independent thrombin generation in patients with non-insulin-dependent diabetes mellitus grouped according to glycemic control.

RESULTS

Platelet-dependent thrombin generation at 30 min after calcium chloride addition was significantly higher in 23 patients with poorly glycemic-controlled non-insulin-dependent diabetes mellitus without complications, such as diabetic retinopathy, nephropathy and neuropathy (hemoglobin [Hb] A1c >/= 9.0%) than in 46 healthy normal subjects (448 +/- 75 vs. 165 +/- 28 mU/min, p < 0.001). Thrombin generation in 31 well controlled diabetic patients without complications (Hb A1c < 9.0%) was intermediate (240 +/- 72 mU/min) between those of the poorly controlled group and healthy normal subjects. Platelet-poor plasma from diabetic patients increased platelet-dependent thrombin generation in normal subjects.

CONCLUSIONS

Coagulability is evidently enhanced in patients with non-insulin-dependent diabetes mellitus compared with that in healthy normal subjects on the basis of assessments of the platelet-dependent thrombin generation, and good glycemic control may help to correct a hypercoagulable state in diabetic patients.

A nude mouse Wilms' tumor line (KCMC-WT-1) derived from an aniridia patient with monoalleleic partial deletion of chromosome 11p

BACKGROUND

A candidate tumor suppressor gene, WT-1, is believed to have an important role in the pathogenesis of Wilms' tumor, especially that occurring in patients with congenital aniridia.

METHODS

To obtain a stable tumor line to work with, Wilms' tumor tissue was serially transplanted in athymic nude mice. Biopsied Wilms' tumor tissue, derived from an aniridia patient, was transplanted subcutaneously to an athymic nude mouse, and then transplanted serially. Histopathologic and molecular biologic studies were performed on the xenotransplants.

RESULTS

The aniridia patient showed partial deletion in one short arm of chromosome 11, which bears the WT-1 gene. The tumor was successfully transplanted in the nude mouse. Although the tumor contained blastemic, organoid, and stromal histologic elements, the organoid element began to decrease after more than 20 passages. Cytogenetic analysis revealed an additional abbreviation of one long arm of chromosome 6. Dot blot analysis showed that the copy number of WT-1 gene was decreased to half the amount in the tumor, in spite of the WT-1 transcript with normal size detected by Northern blotting.

CONCLUSIONS

The tumor is expected to bear one WT-1 gene with minute abnormalities as well as one congenitally deleted gene. This tumor line is useful when examining the effect caused by introduction of WT-1 gene to Wilms' tumor in vivo.

Activation of IL-4 and IL-6 secreting cells by antigen

The number, antigenic specificity and phenotype of cells secreting IL-4 and IL-6 in mice immunized with ovalbumin or keyhole limpet haemocyanin (KLH) in Freund's adjuvant (FA) was studied. The frequency of cells producing either of these cytokines began to rise 6 days post immunization, peaked at 11-14 days post-immunization, and fell to background by 21 days. The number of spleen cells secreting IL-6 was higher than the number producing IL-4 at all time points. Boosting elicited an anamnestic response characterized by a significant increase in the number of cytokine secreting cells within 4 days. Cytokine production was induced in multiple strains of normal mice, and was critically dependent on the use of Complete FA in addition to antigen. Immunization induced IL-4 and IL-6 production in vivo while 'priming' additional cells to release these cytokines when reexposed to soluble antigen in vitro. The latter response was antigen specific and was dominated by non-B/non-T cells. Those cells may serve to boost the immune response in cases of persistent or repeated antigenic challenge.

Induction of potent humoral and cell-mediated immune responses following direct injection of DNA encoding the HIV type 1 env and rev gene products

DNA vaccines have the potential of giving rise to a potent cell-mediated immune response by inducing intracellular synthesis and subsequent antigenic presentation of encoded antigens. We have tested a DNA vaccine specific for human immunodeficiency virus type 1 (HIV-1) by the injection of animals with expression plasmids encoding the HIV-1 envelope protein and the Rev regulatory protein. Injection of both plasmids into mice, rabbits, or macaques was found to induce high levels of specific antibodies capable of efficiently inhibiting both HIV-1 infection and envelope-mediated cell fusion. A readily detectable delayed-type hypersensitivity (DTH) response was demonstrable in injected mice and lymphocytes derived from these proliferated in response to an HIV-1 envelope V3 loop-specific peptide. Interestingly, the injected mice or macaques also developed a strong cytotoxic T lymphocyte (CTL) response against target cells pulsed with the V3 peptide. Taken together, these data demonstrate that injection of HIV-1 gene expression plasmids can induce potent humoral and cell-mediated immune responses and suggest that DNA vaccines may prove to be significantly beneficial as a means of immunizing against HIV-1.

Establishment of two rat osteosarcoma cell lines (YROS-1 and YROS-2) induced by radioactive phosphorus

Two rat osteosarcoma cell lines, YROS-1 and YROS-2, were established from two experimental osteosarcomas and induced by internal irradiation with radioactive phosphorus. Both cell lines formed a monolayer cell sheet in vitro with focal piling. The YROS-1 cells were refractile and spindle or polygonal in shape, whereas the YROS-2 cells were flat, spread and polygonal in shape. Ultrastructurally, the YROS-1 cells had well-developed rough-surfaced endoplasmic reticulum with focal pericellular deposition of calcified matrix, whereas YROS-2 had abundant polysomes and intracytoplasmic filaments. Both cell lines grew stably with population doubling times of 23 and 39 h, respectively. Flow cytometry revealed that YROS-1 was rich in proliferating cells compared to YROS-2, with a higher colony-forming efficiency. YROS-1 showed high alkaline phosphatase activity, while YROS-2 possessed low activity. When subcutaneously transplanted into lumbodorsal area of athymic nude mice, only YROS-1 formed tumors with frequent lung metastasis.

Enantioselective determination of pazinaclone, a new isoindoline anxiolytic, and its active metabolite in rat plasma by high-performance liquid chromatography

A sensitive and specific high-performance liquid chromatographic method has been developed for the simultaneous determination of the enantiomers of pazinaclone (DN-2327), a new anxiolytic agent, and those of its active metabolite, M-II, in rat plasma. Organic solvent extraction of pazinaclone, M-II, and internal standard (I.S.) in plasma was followed by separation of the analytes from other metabolites using an achiral reversed-phase column. Fluorescence detection was employed with excitation and emission wavelengths of 328 and 367 nm, respectively. Separation of all the enantiomers and I.S. was then accomplished with normal- and chiral-phase columns connected in series. For each analyte, the lower quantitation limit was 0.5 ng/ml. The assay has been applied to a chiral inversion study in rats. Chiral conversion from one enantiomer of pazinaclone to the other hardly occurred. This method is suitable for enantioselective pharmacokinetic and toxicokinetic studies in animals.

Effects of exercise and amenorrhea on bone mineral density in teenage runners

In order to elucidate whether exercise and calcium intake can offset bone loss due to hypoestrogenemia in teenage girls, the lumbar and femoral bone mineral density (BMD) in elite amenorrheic runners (group 1 (n = 8)) was compared with those in eumenorrheic athletes (group 2 (n = 15)) and two groups of eumenorrheic non-athletic subjects, group 3 (n = 14), and group 4 (n = 15). BMD was measured by dual energy x-ray absorptiometry. The subjects in group 1 lived in the dormitory, and their calcium intake was controlled to > 1400 mg/day. The subjects in groups 1, 2 and 3 were age matched (16-17 years old), but the body weight of those in group 2 was significantly greater than that of others. The subjects in groups 1, 3 and 4 were weight matched, but group 4 subjects were older by 5 years (21.0 +/- 0.2 years old). The lumbar BMD of group 1 was 1.0460 +/- 0.0259, which was not statistically different from those in the other groups, while the femoral BMD of group 1 was significantly higher than those of groups 3 and 4 at trochanter. The lumbar and femoral BMD of group 2 was significantly higher than in groups 3 and 4, but was not statistically different from group 1. There were no significant differences in serum parathyroid hormone levels, but osteocalcin and calcitonin levels of group 1 were significantly lower than those of groups 2 and 3, and groups 2, 3 and 4, respectively, suggesting that the rate of bone formation is suppressed in amenorrheic runners.(ABSTRACT TRUNCATED AT 250 WORDS)

IgE receptor-positive non-B/non-T cells dominate the production of interleukin 4 and interleukin 6 in immunized mice

The phenotype and antigenic specificity of cells secreting interleukin (IL) 4, IL-6, and interferon gamma was studied in mice during primary and secondary immune responses. T lymphocytes were the major source of interferon gamma, whereas non-B/non-T cells were the dominant source of IL-4 and IL-6 in the spleens of immunized animals. Cytokine-secreting non-B/non-T cells expressed surface receptors for IgE and/or IgG types II/III. Exposing these cells to antigen-specific IgE or IgG in vivo (or in vitro) "armed" them to release IL-4 and IL-6 upon subsequent antigenic challenge. These findings suggest that non-B/non-T cells may represent the "natural immunity" analogue of CD4+ T helper type 2 cells and participate in a positive feedback loop involved in the perpetuation of T helper type 2 cell responses.

Effects of rhIL-1 alpha, rhIL-1 beta, and rhIL-1 receptor antagonist on erythroid progenitors (CFU-E and BFU-E) in human bone marrow

Interleukin-1 (IL-1) is known to promote the production of colony-stimulating factor (CSF) and to possess the ability to protect the bone marrow suppression in granulocyte-macrophage (GM) series associated with radiotherapy or chemotherapy. There are conflicting reports concerning the action of IL-1 on erythroid progenitors, however, and no consensus has been established. In the present study, the influences of recombinant human IL-1 alpha (rhIL-1 alpha), rhIL-1 beta, and rhIL-1 receptor antagonist (rhIL-1ra) on erythroid progenitors (colony-forming units-erythroid, CFU-E; and burst-forming units-erythroid, BFU-E) in human bone marrow were studied. rhIL-1 alpha and rhIL-1 beta (1-1000 pg/mL) enhanced the CFU-E and BFU-E growth in human nonadherent (NA) bone marrow cells. rhIL-1 alpha and rhIL-1 beta also stimulated the formation of CFU-E and BFU-E in the NA and T cell-depleted bone marrow fraction. Moreover, rhIL-1 alpha and rhIL-1 beta enhanced the CFU-E and BFU-E in the CD34+ bone marrow cell fraction. These data and the results of limiting dilution analysis indicate that the stimulatory effect of IL-1 may consist of direct actions on erythroid progenitors. The enhancing effect of rhIL-1 alpha and rhIL-1 beta on erythroid progenitors was inhibited by rhIL-1ra. These data suggest that the stimulatory effect of IL-1 on CFU-E and BFU-E is mediated via the IL-1 receptor.

[Analysis of T cell subsets in autoimmune hemolytic anemia patients]

To clarify a role of immunoregulatory T cells in the pathophysiology of autoimmune hemolytic anemia (AIHA), we investigated T cell subsets in the peripheral blood of 15 patients with AIHA by two color analysis using flow cytometry. Consequently both CD4+ cells and CD4+CD45RA+ cells decreased in proportion, irrespective of the disease activity (active or remission phase). CD4+CD45RA+ cells are regarded as naive T cells. Incidentally the ratio of CD45RA+ cells in CD4+ cells also fell in the low level in active phase, but it recovered to the normal ratio in remission. On the other hand, CD8+ cells and CD8+ +S6F1+ cells that may represent activated cytotoxic T lymphocytes increased in active phase and then both entered the normal range in remission. These findings suggest that AIHA could be caused partly by the alternative balance of CD4+CD45RA+ cells probably constituting a member of IRT and moreover by the activation of CTL.

[High resolution MR imaging of the inner ear apparatus using 3D-Fast spin echo sequence]

To evaluate the efficacy of high resolution MR imaging of the inner ear with 3D-Fast spin echo sequence, one volunteer and 12 patients were imaged with a 1.5 T MR scanner. High resolution T2-weighted images were obtained with a head coil in 13 minutes, and the voxel size was 0.39mm x 0.45mm x 1.2mm in most subjects. Original images and maximum intensity projection (MIP) images of the inner ear were evaluated. On original images, the endolymphatic duct was visualized in 72% of subjects, the cochlear aqueduct in 96%, three branches of the cranial nerves in the internal auditory canal in 100%, and flow void of the vessel in the cerebellopontine angle in 100%. On MIP images, more than two cochlear turns were visualized in 92% of subjects, three semicircular canals in 100%, and the anterior and posterior ampulla in 100%. MR imaging of the inner ear with 3D-Fast Spin Echo sequence provides a variety of useful information regarding the anatomy around the inner ear.

Sensitive determination of methotrexate in monkey plasma by high-performance liquid chromatography using on-line solid-phase extraction

A high-performance liquid chromatographic method was developed for the sensitive determination of methotrexate (MTX) in monkey plasma using direct injection and on-line solid-phase extraction. After application of a 100-microliters aliquot of plasma to a pre-treatment column, the column was washed with 0.02 M phosphate buffer (pH 7) to eliminate plasma proteins and endogenous substances, and subsequently the adsorbed MTX was eluted. The MTX fraction was transferred to an analytical column by a column-switching (heart-cutting) technique, and MTX was analyzed using ion-pair chromatography with tetrabutylammonium bromide. More than 50 injections could be performed onto one pretreatment column. The accuracy, precision, reproducibility and linearity were satisfactory over a wide range of MTX concentrations (5-1000 ng/ml). The quantitation limit was 5 ng/ml with a signal-to-noise ratio of 5. The method was suitable for the pharmacokinetic study of MTX in monkey.

Sensitive high-performance liquid chromatographic determination of chlorpheniramine in human serum using column switching

A sensitive method for the determination of chlorpheniramine in human serum was developed using column-switching high-performance liquid chromatography (HPLC) with ultraviolet detection at 210 nm. The analyte was extracted with diethyl ether from alkalinized serum. After evaporation of the organic layer, the reconstituted residue was analyzed by HPLC using a heart-cut technique. Good recoveries of the analyte from spiked human serum samples were obtained with a coefficient of variation below 7%. A good linear response was obtained for the concentration range 0.5-50 ng/ml, with a correlation coefficient higher than 0.999. The lower limit of quantitation for chlorpheniramine in human serum was 0.5 ng/ml. The method was satisfactorily applied to the determination of chlorpheniramine in human serum after oral administration of chlorpheniramine maleate.

High-performance liquid chromatographic determination of phenylephrine in human serum using column switching with fluorescence detection

A method for the determination of total phenylephrine (free plus conjugated) in human serum was developed using column-switching high-performance liquid chromatography (HPLC) with fluorescence detection. After serum was deproteinized with acetonitrile, the conjugated phenylephrine was hydrolyzed with diluted hydrochloric acid. The solution was evaporated to dryness. The reconstituted residue was analyzed with HPLC using a heart-cut technique. Good recoveries of the analytes from spiked human serum samples were obtained with small coefficients of variation. A good linear response was obtained for the concentration range 5-500 ng/ml. The lower limit of quantitation for phenylephrine in human serum was 5 ng/ml. The method was applied to the determination of phenylephrine in human serum after oral administration of phenylephrine hydrochloride.

Establishment of three rat soft tissue tumor cell lines with different degrees of myogenic differentiation

Soft tissue malignancies often show divergent differentiation, including myogenic lineage. Five rat tumors induced with 20-hydroxymethylcholanthrene (20-OH-MCA), were cultured in vitro, and three cell lines (YMC-1, YMC-2, YMC-3) were established from them. YMC-2 and -3 cells were spindle-shaped, and YMS-1 cells round and epithelioid. In confluency, YMC-3 cells formed myotubes. The nude mouse xenotransplants showed morphological features consistent with their myogenic phenotypes. Muscle-specific enzyme activities were highest in YMC-3 cells. These lines may be useful in the investigation of the myogenic differentiation of undifferentiated mesenchymal cells.