Cu2+ reveals amiloride-induced activation and blocking of non-selective cation channel in larval bullfrog skin

The non-selective cation channel (NSCC) in the larval bullfrog skin contributes to the short-circuit current (SCC) across the skin. The effects of amiloride and acetylcholine on the SCC were examined in the presence or absence of Cu2+ to determine whether the amiloride binding site mediating activation or that mediating inhibition of the channel is blocked by Cu2+ and whether amiloride and acetylcholine share a common binding site on the NSCC. The skin of tadpoles raised in aldosterone was examined with K-Ringer present on the apical side to potentiate the SCC. Amiloride (10(-4) M) transiently increased SCC in the absence of Cu2+. Apical application of 500 microM Cu2+ increased the SCC. In the presence of Cu2+, amiloride decreased the SCC. In contrast, acetylcholine (1 mM) transiently increased SCC whether Cu2+ was present or not. These results suggest that there are two binding sites for amiloride on the NSCC, whereby the site that activates the channel is blocked by Cu2+ while the site that inhibits it is not, and that the binding sites for acetylcholine and amiloride may be different.

Acute promyelocytic leukemia with apparently normal karyotype: molecular findings and response to all-trans retinoic acid

Acute promyelocytic leukemia (APL) is specifically associated with a reciprocal translocation, t(15; 17)(q22; q21), leading to the formation of a fusion of the retinoic acid receptor-alpha (RARA) gene and the promyelocytic leukemia (PML) gene. However, there are several reports describing APL cases lacking the t(15; 17). Many such cases are those bearing variant translocations involving chromosomes 15 or 17, and those with no chromosomal aberrations have rarely been reported. We have studied a patient with APL showing an apparently normal karyotype which was confirmed by spectral karyotyping (SKY). A submicroscopic PML-RARA fusion was identified by reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent in situ hybridization (FISH). All-trans retinoic acid (ATRA) was effective as the initial therapy for remission induction and as the reinduction therapy after a relapse. The present study shows the key role of the fusion of PML-RARA in the responsiveness to ATRA as well as in the leukemogenesis of APL.

Thalamotomy caused by cardioversion in a patient treated with deep brain stimulation

Deep brain stimulation (DBS) has been applied mainly for the treatment of intractable pain and involuntary movement disorders. Based on the rising numbers of patients undergoing DBS therapy, the possibility of emergent application of cardioversion for the treatment of occasional severe arrhythmia in DBS patients has also increased. However, there has been insufficient discussion about cardioversion in DBS patients. We employed a radiofrequency receiver that transmits to the brain impulses provided by an external generator through an antenna applied to the skin in front of the receiver. We experienced a patient who displayed almost complete cessation of his action tremor with thalamic stimulation. He also developed central dysesthetic pain and showed complete disappearance of his action tremor, even without stimulation, following successful application of cardioversion. It is considered that slight changes in the high-voltage electrical current or high-voltage electrical current spread induced central dysesthetic pain and almost identical effects to thalamotomy. We report for the first time a case of thalamotomy induced by cardioversion in a DBS patient. Clearly, we need to bear in mind that cardioversion has the capability to cause brain lesions in DBS patients with a radiofrequency receiver implanted subcutaneously at the anterior chest wall.

A novel series of thromboxane A2 synthetase inhibitors with free radical scavenging and anti-peroxidative activities

A novel series of indoline derivatives with imidazole and carboxyl moieties were synthesized and evaluated for their thromboxane A2 (TXA2) synthetase inhibiting, radical scavenging and anti-peroxidative activities. Among the compounds synthesized, 3-[5-substituted-3-[2-(imidazol-1-yl)ethyl]indolin-1-yl]propionic acids showed free radical scavenging activity and inhibitory effects on lipid-peroxidation of rat brain homogenate and on arachidonate-induced TXA2-dependent aggregation of rabbit platelets. The anti-platelet and anti-peroxidative activities were related to the lipophilicity of the 5-substituent. The 5-hexyloxy derivative (13) showed about 35-fold higher inhibitory activity on TXA2 synthesis than that of ozagrel and about 100-fold higher activity on lipid peroxidation than that of alpha-tocopherol. Compound 13 showed in vivo anti-thrombotic effect in mice and ex vivo anti-peroxidative activity in rats.

Intraoperative wake-up procedure with propofol and laryngeal mask for optimal excision of brain tumour in eloquent areas

This is the first thesis describing a new technique for awake craniotomy using a laryngeal mask. Awake craniotomy with propofol infusion has become increasingly popular for the optimal excision of brain tumours located in eloquent areas. During awake craniotomy, tracheal intubation is not performed and propofol infusion is limited to within doses which render the patient just sedated. This asleep-awake procedure is occasionally associated with difficulty in controlling brain volume, especially in patients with a significant mass effect of their brain tumours, since sufficient sedation with propofol tends to cause hypercapnea. We report an intraoperative wake-up procedure employing a laryngeal mask, which enables general anaesthesia to be performed at a sufficient dose of propofol and with control of the brain volume under mechanically assisted ventilation. Before the beginning of cortical mapping, propofol infusion is completely terminated, so allowing the patient to wake up within 5-15 min. Following completion of the tumour excision, general anaesthesia is re-induced at a sufficient dose of propofol. The laryngeal mask can be temporarily removed and repositioned with ease, if necessary. In our experience, this technique is applicable for the optimal excision of brain tumours, especially in patients who are very obese or those who have very large lesions.

Determination of three isoforms of the receptor activator of nuclear factor-kappaB ligand and their differential expression in bone and thymus

The receptor activator of nuclear factor (NF)-kappaB ligand [RANKL; also known as tumor necrosis factor-related activation-induced cytokine, osteoprotegerin ligand, and osteoclast differentiation factor] is known to bind with the receptor activator of NF-kappaB (RANK) and act not only as a key factor for osteoclastogenesis but also as a regulator of lymphocyte development. In this study, we found two additional isoforms of RANKL. RANKL 2 has a shorter intracellular domain than the original RANKL (RANKL 1), and RANKL 3 lacks a transmembrane domain and was thought to act as a soluble form. In the bone marrow stromal cell line ST2 and preosteoblastic cell line MC3T3-E1, all three RANKL isoforms were detected, but the expression of RANKL 2 was preferentially suppressed by treatment with 1alpha,25-dihydroxyvitamin D(3) and dexamethasone. In young adult thymus, CD4(-)CD8(-) double-negative cells were positive for all three isoforms, CD4(+)CD8(+) double-positive cells were positive for RANKL 1 and RANKL 3 but negative for RANKL 2, and CD4(+)CD8(-) and CD4(-)CD8(+) single-positive cells were positive for all three isoforms. Immunofluorescence analyses of NIH3T3 cells transfected with each RANKL isoform indicated that the three RANKL isoforms were translated, and RANKL 2 protein predominantly stayed in the endoplasmic reticulum and Golgi networks. These results indicate that there are three kinds of RANKL-RANK pathways. The presence of multiple RANKL-RANK pathways suggests a more complicated RANKL-RANK system for osteoclastogenesis or T cell differentiation than previously thought.

Genomic structure and chromosomal localization of the gene encoding TRAX, a Translin-associated factor X

The TRAX gene encodes a Translin-associated 33-kDa protein partner, TRAX. The TRAX protein has extensive amino acid homology with Translin, and contains bipartite nuclear targeting sequences, suggesting a possible role in the selective nuclear transport of Translin lacking any nuclear targeting motifs. In the present study, genomic clones of the human TRAX gene were isolated to determine the complete genomic organization. The genomic structure of the human TRAX gene was similar to that of the human Translin gene, consisting of six exons and five introns, encompassing approximately 27kb in genomic DNA. Northern blot analysis revealed a predominant transcript of approximately 2.7kb, and its distribution in various tissues was like that of Translin. Chromosomal mapping by fluorescence in situ hybridization (FISH) analysis allowed localization of the TRAX gene to human chromosome lq41.

Thrombotic stroke in a child with diarrhea-associated hemolytic-uremic syndrome with a good recovery

A boy aged 3.5 years with post-diarrheal hemolytic-uremic syndrome (HUS) was referred to our hospital because of convulsion and stupor. He had been admitted to a regional hospital with a 3-day history of bloody diarrhea, colic abdominal pain and fever. Two days later, he had complained of generalized seizures and oliguria. On admission, he developed anuria, and serum blood nitrogen and creatinine increased to 56 mg/100 ml and 2.8 mg/100 ml, respectively. Platelets decreased to 42,000/microl. Under the diagnosis of HUS, a continuous hemodiafiltration treatment had to be instituted. Computed tomography of his head at hospital day 5 revealed abnormal low density area of infarction with edema in both the basal ganglia involving with the posterior limb of internal capsule. Serum titer of IgM antibody to Escherichia coli O157 showed positive value. Although his anuria and stupor persisted over 10 days, he recovered without serious complications. These clinical observations may indicate that patients with similar lesions do not necessarily have serious morbidity.

Increase in spontaneous action potentials and sensitivity in response to norepinephrine in dorsal root ganglion neurons of adjuvant inflamed rats

To gain an understanding of the cellular mechanisms of hyperalgesia and spontaneous pain in adjuvant-induced chronic inflammation, we investigated the effects of nerve growth factor (NGF), which is known to increase in inflamed tissues and to cause hyperalgesia, on the spontaneous activities and norepinephrine-induced excitation of dorsal root ganglion (DRG) neurons. Intracellular recordings were obtained from freshly dissociated and cultured DRG neurons (<30 microm) from intact and adjuvant inflamed (AI) rats. Of more than 100 freshly dissociated DRG neurons from the intact rats, none produced spontaneous action potentials, whereas 23% of the neurons from the AI rats did. Spontaneous activities were induced in 34% neurons from intact rats when cultivated for one day with NGF. No neurons from the intact rats responded to norepinephrine (NE), irrespective of whether they were freshly dissociated or cultured with NGF. In contrast, 11% of neurons from the AI rats, both freshly dissociated and cultured without NGF, had a small depolarization in response to NE. The present results suggest that, in AI rats NGF plays an important role in inducing spontaneous activities in DRG neurons, but not in inducing sensitivity to NE.

Effect of dietary conjugated linoleic acid on lipid peroxidation and histological change in rat liver tissues

The effect of dietary conjugated linoleic acid (CLA) on hepatic lipid parameters in Sprague-Dawley rats was examined. When rats were fed a diet containing CLA at 0 (control), 1, or 2% of the weight of the amount of food given for 3 weeks, the liver weight exhibited a slight increase in the CLA-fed groups, although the difference was not significant. Lipid accumulation in the hepatocytes of CLA-fed rats was also demonstrated by electron microscopic observation. In addition, the liver thiobarbituric acid reactive substances levels were significantly higher in the 2 wt % CLA group than in the other two dietary groups, and the levels of phosphatidylcholine hydroperoxide were higher in CLA-fed groups when compared to that of the control group. On the other hand, the serum lipid peroxide levels were comparable among all three dietary groups. Levels of triglycerides in the white adipose tissue (WAT) and serum nonesterified fatty acid (NEFA) were reduced in a CLA-dose-dependent manner. CLA was shown to accumulate in the WAT much more than in the serum or liver. These results suggest that CLA accelerates the decomposition of storage lipids in WAT and the clearance of serum NEFA levels, resulting in lipid peroxidation and a morphological change in the liver.

CLIP-derived self peptides bound to MHC class II molecules of medullary thymic epithelial cells differ from those of cortical thymic epithelial cells in their diversity, length, and C-terminal processing

Medullary thymic epithelial cells (mTEC) are able to present soluble antigens to CD4+ helper T cell lines, whereas cortical thymic epithelial cells (cTEC) are not (Mizuochi, T., et al., J. Exp. Med. 1992. 175: 1601-1605). In addition, class II heterodimers from mTEC migrated with apparently less relative molecular mass in SDS-PAGE than those from cTEC (Kasai, M., et al., Eur. J. Immunol. 1998. 28:1867-1876). To investigate the cause of the distinct migration profiles of class II heterodimers in both TEC types, class II heterodimer-associated peptides were analyzed by matrix-assisted laser desorption ionization mass spectrometry. Self peptides from cTEC were shown to vary moderately in length and to be highly diverse, including low amounts of CLIP (class II-associated invariant chain peptide) variants. On the other hand, self peptides from two mTEC consisted predominantly of two CLIP variants with exceptional C-terminal extensions. C-terminally overhanging residues of CLIP in mTEC may be responsible for the distinct migration of class II heterodimers in SDS-PAGE. Differences in migration of class II heterodimers on SDS gels was also observed in H2-DM+ vesicles isolated from both TEC. The possible contribution of self peptides bound to class II heterodimers in TEC to positive or negative selection of T cells in the thymus is discussed.

Interpersonal constructs of pregnant married women during pregnancy and postpartum period as perceptions of family members

Interpersonal constructs and their dynamics in pregnant women during the perinatal period were investigated using a symbol figure placement technique and a semantic differential test. 16 pregnant women represented their interpersonal perceptions of family members (husband, mother, father, mother-in-law, father-in-law, and child) at four different times (34 weeks of pregnancy, 37 weeks of pregnancy, and 3 days and 30 days after delivery). Two tests indicated positive perceptions of the pregnant women (cohesion, confidence, and dependence) of family members changed over the perinatal period and their interpersonal perceptions of self-husband and self-child were the most positive next to self-mother. Based upon these findings, the support system for pregnant women was discussed.

Thymic epithelial cells responsible for impaired generation of NK-T thymocytes in Alymphoplasia mutant mice

We have previously shown that the generation of an NK1.1+TCRalphabeta+ (NK-T) cell population is severely impaired in an alymphoplasia mutant (aly/aly) mouse strain and the defect resides in the thymic environment. In the present study, to elucidate the thymic stromal component(s) that affects the development of NK-T cells, radiation bone marrow chimeras were established with the aly/aly mouse as a donor and either the beta2 microglobulin knockout (beta2m-/-) or the CD1d1-/- mouse that also lacks the NK-T cell population as a recipient. A normal population of NK-T cells with a typical NK-T phenotype and functions was detected in both the thymus and the spleen of these chimeras. These findings indicated that a radiation-resistant CD1(-) component of the thymus supported generation of functional NK-T cells from aly/aly precursors. Furthermore, transfer of an intact medullary thymic epithelial cell line into aly/aly thymus significantly induced the generation of NK-T cells in the thymus. These findings suggest that CD1 molecules of bone marrow-derived cells and the medullary epithelial cells acted in concert in the generation of the NK-T cell population and that a function(s) of the medullary thymic epithelial cells other than direct presentation of CD1 molecules to the NK-T precursors is indispensable for the development of NK-T cells.

Translin binds to the sequences adjacent to the breakpoints of the TLS and CHOP genes in liposarcomas with translocation t(12;6)

Myxoid and round-cell liposarcomas share the translocation t(12;16)(q13;p11) creating the TLS-CHOP fusion gene as a common genetic alteration. We previously reported several unique characteristics of genomic sequences around the breakpoints in the TLS and CHOP loci, and among them was the presence of consensus recognition motifs of Translin, a protein that associates with chromosomal translocations of lymphoid neoplasms. We further extended our search for Translin binding motifs in sequences adjacent to breakpoints and investigated whether Translin binds to these sequences in vitro by mobility-shift assay. Computer-assisted search found sequences highly homologous (>70%) with Translin binding motifs adjacent to the breakpoints in 10 out of 11 liposarcomas with the TLS-CHOP fusion genes. All of 13 oligonucleotides corresponding to the putative binding sequences in these cases bind to Hela cell extract and also recombinant Translin protein, although the binding affinity of each motif showed considerable differences. The DNA-protein complex formation was inhibited by non-labeled competitor or anti-Translin antibody, suggesting the specificity of the complex formation. Considering the high incidence and specific binding property, the presence of Translin binding motif may be one of the important determinants for the location of breakpoints in the TLS and CHOP genes in liposarcomas.

Clinical significance of major and minor bcr/abl chimeric transcripts in essential thrombocythemia

BACKGROUND

Contradictory results have been reported in terms of detecting bcr/abl transcripts in patients with essential thrombocythemia. The aim of this study was to investigate whether the bcr/abl transcript could be found in patients with essential thrombocythemia (ET).

METHODS

The bcr/abl transcript was amplified by the RT-nested PCR method using RNA extract from leukocytes taken from 14 essential thrombocythemia patients. The amplified DNAs were electrophoresed in 1% agarose and visualized with ethidium bromide. The DNA bands associated with the bcr/abl transcript were then extracted and followed by DNA sequence analysis.

RESULTS

Major bcr/abl transcripts of the b3a2 type and minor ones of the e1a2 type were found in one and two ET patients, respectively. The incidence of bcr/abl transcripts was 21.4% (three of 14 patients).

CONCLUSION

Our experiments confirmed that bcr/abl transcripts are present in some patients with essential thrombocythemia.

Aberrant expression of HLA-G antigen in interferon gamma-stimulated acute myelogenous leukaemia

We have analysed the expression of HLA-G in 40 leukaemia samples of various subtypes [seven cases of acute lymphoblastic leukaemia (ALL), 28 cases of acute myelogenous leukaemia (AML), three cases of chronic myelogenous leukaemia (CML) and two cases of chronic lymphocytic leukaemia (CLL)] by flow cytometry using HLA-G-specific monoclonal antibody. No leukaemia samples expressed HLA-G without incubation with interferon (IFN)-gamma. However, six out of 28 (21%) AML samples expressed HLA-G upon incubation with IFN-gamma. These six samples derived from one out of seven M2, two out of eight M4 and three out of five M5. The results indicated that AML cells, especially myelomonocytic leukaemia samples, are capable of expressing the HLA-G molecule.

Dietary conjugated linoleic acid increases immunoglobulin productivity of Sprague-Dawley rat spleen lymphocytes

The dietary effects of conjugated linoleic acid (CLA) on Ig production of Sprague-Dawley rats were examined at various doses such as 0 (control), 0.05, 0.10, 0.25, and 0.50%. CLA increased IgG and IgM production of spleen lymphocytes in a dose-dependent manner, and these levels reached a plateau at 0.25%. IgA production was not detected in the control group, while it was detected in all CLA-fed groups and IgA productivity of spleen lymphocytes increased in a dose-dependent manner at the doses from 0.05 to 0.50%. Dietary CLA did not affect serum Ig levels. The major fatty acid composition of spleen lymphocytes was not affected by dietary CLA, which itself was hardly incorporated into the cells. In an in vitro assay, the effects of CLA and its oxidative derivatives, furan type fatty acids, on Ig productivity were also examined. As a result, 100 microM CLA suppressed Ig production of spleen lymphocytes and the degree was as follows IgA > IgG > IgM. Each CLA isomer and the furan type fatty acids also suppressed Ig production but the degree was weaker than the mixture of CLA isomers. In this result, dietary CLA increased Ig productivity of spleen lymphocytes in vivo.

Pepstatin A-sensitive aspartic proteases in lysosome are involved in degradation of the invariant chain and antigen-processing in antigen presenting cells of mice infected with Leishmania major

We previously reported that CA074, a specific inhibitor of cathepsin B, significantly deviated immune responses from the disease-promoting Th2 type to the protective Th1 type in BALB/c mice infected with Leishmania major. Herein, we found that pepstatin A-sensitive aspartic proteases (PSAP) in lysosomes seem to play a different role from that of cathepsin B in antigen-processing and Ii-degradation. That is, cathepsin B appears to digest 16-, 28-, and 31-kDa peptides of soluble leishmania antigen (SLA), whereas PSAP seems to process mainly 28-kDa peptides. Furthermore, the latter protease contributed to the degradation of Ii but cathepsin B did not. Following treatment with pepstatin A, both Th1 and Th2 responses were profoundly suppressed in resistant DBA/2 mice (H-2(d)) and in susceptible BALB/c mice (H-2(d)), and both strains of mice became markedly susceptible compared with the untreated groups, probably owing to failure in degradation of Ii and partly to failure in digestion of 28-kDa peptide.

Conjugated linoleic acid supplementation reduces adipose tissue by apoptosis and develops lipodystrophy in mice

Conjugated linoleic acid (CLA) is a naturally occurring group of dienoic derivatives of linoleic acid found in beef and dairy products. CLA has been reported to reduce body fat. To examine the mechanism(s) of CLA reduction of fat mass, female C57BL/6J mice were fed standard semipurified diets (10% fat of total energy) with or without CLA (1% wt/wt). Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick endlabeling (TUNEL) and DNA fragmentation analysis revealed that fat-mass decrease by CLA was mainly due to apoptosis. Tumor necrosis factor (TNF)-alpha and uncoupling protein (UCP)-2 mRNA levels increased 12- and 6-fold, respectively, in isolated adipocytes from CLA-fed mice compared with control mice. Because it is known that TNF-alpha induces apoptosis of adipocytes and upregulates UCP2 mRNA, a marked increase of TNF-alpha mRNA with an increase of UCP2 in adipocytes caused CLA-induced apoptosis. However, with a decrease of fat mass, CLA supplementation resulted in a state resembling lipoatrophic diabetes: ablation of brown adipose tissue, a marked reduction of white adipose tissue, marked hepatomegaly, and marked insulin resistance. CLA supplementation decreased blood leptin levels, but continuous leptin infusion reversed hyperinsulinemia, indicating that leptin depletion contributes to the development of insulin resistance. These results demonstrate that intake of CLA reduces adipose tissue by apoptosis and results in lipodystrophy, but hyperinsulinemia by CLA can be normalized by leptin administration.

Acute reduction of serum leptin level by dietary conjugated linoleic acid in Sprague-Dawley rats

The purpose of this study was to clarify the effect of conjugated linoleic acid on lipid accumulation in adipose tissue. Sprague-Dawley rats were fed a diet containing 2% conjugated linoleic acid for 1, 3, 6, and 12 weeks. In rats fed 2% conjugated linoleic acid, the weight of perirenal white adipose tissue was comparable with that of rats fed a conjugated linoleic acid-free diet. For fatty acid composition of perirenal white adipose tissue, both 16:1/16:0 and 18:1/18:0 ratios were significantly lower in the conjugated linoleic acid-fed group than the control group. Although there was no remarkable difference in serum triglyceride, total cholesterol, and phospholipid levels between dietary groups, serum leptin level was significantly lower than the control group, and lipid content in the perirenal white adipose tissue exerted a tendency toward low compared to the control value at 1-week feeding. On the other hand, leptin level in perirenal white adipose tissue was significantly lower in the conjugated linoleic acid-fed group than the control group at 12-week feeding. In conclusion, these observations suggest dietary conjugated linoleic acid is an acute reducer of serum leptin level. This may afford an explanation of the mechanism of anti-obesity effect in conjugated linoleic acid.

Randomized comparison of mobilization kinetics of circulating CD34+ cells between biweekly CHOP and dose-escalated CHOP with the prophylactic use of lenograstim (glycosylated rHuG-CSF) in aggressive non-Hodgkin's lymphoma. The lenograstim/Lymphoma Study Group

High-dose chemotherapy with autologous hematopoietic stem cell transplantation has been expected to result in a promising outcome in high risk aggressive non-Hodgkin's lymphoma (NHL). However, it remains unknown what type of initial chemotherapy is optimal, especially regarding progenitor cell mobilization. Sixty-three untreated patients with aggressive NHL in a high risk group were randomized to either a biweekly arm with 8 cycles of standard CHOP or 6 cycles of the dose-escalated CHOP arm with cyclophosphamide 1.5 g/m2 and doxorubicin 70 mg/m2. Lenograstim (glycosylated rHuG-CSF 2.0 microg/kg/day) was administered daily from day 3 to patients in both arms. The mobilization effect of the two regimens on circulating CD34+ cells was evaluated. Twenty-seven of 29 patients in the biweekly CHOP arm and 33 of 34 patients in the dose-escalated CHOP were assessable. Dose-escalated CHOP yielded a significantly higher number of circulating CD34+ cells in the first cycle compared with biweekly CHOP (p=0.05). The peak number of circulating CD34+ cells with biweekly CHOP did not significantly change from cycle to cycle; however, in dose-escalated CHOP, the peak number of circulating CD34+ cells mobilized after the fifth and sixth cycle was lower than after the first cycle (p=0.07 and 0.009, respectively). Routine conventional-dose chemotherapy and low-dose G-CSF can mobilize sufficient CD34+ cells in patients with aggressive NHL. The mobilization kinetics of circulating progenitor cells in patients with aggressive NHL is dependent on the dosage and schedule of CHOP.

Trisomy 10 in acute myeloid leukemia. Three additional cases from the database of the Japan Adult Leukemia Study Group (JALSG) AML-92 and AML-95

To clarify the clinical and hematologic features of a rare numerical chromosome abnormality, we searched for trisomy 10 in acute myelogenous leukemias (AMLs) using the database of the Japan Adult Leukemia Study Group (JALSG) AML 92 and 95. Among the sequentially registered patients of JALSG-AML 92 (655 patients) and JALSG-AML 95 (531 patients), chromosome results were obtained in 1,074 patients (90.6%), and we found 3 patients with trisomy 10 as a sole abnormality. The first patient had an AML-M1 morphology with CD7 antigen; the patient obtained complete remission (CR) with the first course of chemotherapy. The second patient had an AML-M1 morphology without expressing CD7 antigen; this patient obtained CR, but relapsed 3 months later, and underwent allogeneic bone marrow transplantation. He suffered from chronic graft-versus-host disease and expired 38 months after the AML diagnosis. The third patient had AML-M0 with CD7 positivity. He obtained CR; however, brain abscess and cerebral hemorrhage occurred. In the literature, the mean age of patients with trisomy 10 AML is 57.8 years, the gender ratio is M/F = 1.5, and the frequency of M0/M1/M2 is 85.7%. A high incidence (81. 8%) of CD7 expression of leukemia cells is notable. About 73% of patients survived for greater than 12 months.

The fas antigen is involved in thymic T-cell development as a costimulatory molecule, but not in the deletion of neglected thymocytes

To determine whether the Fas antigen (Fas) is involved in thymic T-cell development, we introduced the lymphoproliferation (lpr) mutation into a T-cell receptor-alphabeta transgenic mouse (DO10 mouse) and generated 4 genotypes of T-cell receptor transgenic mice homozygous or heterozygous for the lpr mutation with selecting or nonselecting H-2 haplotype. Unexpectedly, we found that the homozygous Fas mutation (lpr/lpr) induced a marked reduction in CD4(+)CD8(+) double-positive (DP) thymocytes in mice with nonselecting background and that the thymus showed severe cortical atrophy. We also found that the homozygous Fas mutation inhibited the activation of DP thymocytes in the process of positive selection, as indicated by the lower levels of CD5 and CD69 expressions on DP thymocytes in lpr/lpr mice with both selecting and nonselecting background than those of lpr/+ mice. Furthermore, we found a significant skewing from CD4(+) to CD8(+) single-positive thymocytes in lpr/lpr mice with nonselecting background compared with that in the corresponding lpr/+ mice. Taken together, these results indicate that Fas is involved in thymic T-cell development, DP thymocyte generation and positive selection, as a costimulatory molecule but is not involved in the deletion of neglected thymocytes.

Dendritic translocation of the rat ferritin H chain mRNA

To elucidate the mechanism regulating the selective transport of mRNAs to synaptic sites, we compared the synaptosomal mRNAs with those from the forebrain using the differential display method. The ferritin H chain mRNA was found to be highly enriched in the synaptosomes. In situ hybridization for the ferritin H chain mRNA in the cultured dissociated neurons and in the hippocampal brain slices demonstrated its existence in the dendritic region. These data clearly indicate the selective translocation of the ferritin H chain mRNA into the dendrites and suggested the local expression of ferritin at the synapse.

Bioavailable acyl-CoA: cholesterol acyltransferase inhibitor with anti-peroxidative activity: synthesis and biological activity of novel indolinyl amide and urea derivatives

We synthesized a series of indoline derivatives with an amide or urea moiety and examined their inhibitory effects on acyl-CoA:cholesterol acyltransferase (ACAT) activity, lipid-peroxidation and serum cholesterol levels in experimental animals. Among the derivatives synthesized, a series of N-(1-alkyl-4,6-dimethylindolin-7-yl)-2,2-dimethylpropanamides++ + potently inhibited rabbit intestinal ACAT activity and lipid-peroxidation of rat brain homogenate. The effect on ACAT activity was related to the length of the alkyl chain at the 1-position of indoline. N-(4,6-Dimethyl-1-octylindolindolin-7-yl)-2,2-dimethylpropanami de hydrochloride (55) showed inhibitory effects on intestinal and hepatic ACAT activity slightly weaker than those of YM-750, and an inhibitory effect on low density lipoprotein (LDL)-peroxidation similar to that of probucol. Compound 55 also reduced serum cholesterol at 10 mg/kg/d in hyperlipidemic rats and 20 mg/kg/d in normolipidemic hamsters. The plasma concentration of 55 reached 716 ng/ml in dogs (10 mg/kg, p.o.), which is an effective concentration against hepatic ACAT activity and LDL-peroxidation. In conclusion, compound 55 is a novel bioavailable ACAT inhibitor with anti-peroxidative activity and is thus a promising anti-atherosclerotic and anti-hyperlipidemic drug. Indoline proved to be a useful pharmacophore for molecular design of new anti-peroxidative drugs.

Factors affecting the survival of frozen-thawed mouse spermatozoa

Mouse epididymal spermatozoa were frozen in solutions containing various compounds with different molecular weights, and the factors affecting the postthawing survival were examined. Monosaccharides (glucose, galactose) had almost no protective effect regardless of the concentration and the temperature of exposure. On the other hand, disaccharides (sucrose, trehalose) and trisaccharides (raffinose, melezitose) resulted in higher survival rates, especially at a concentration of around 0.35 mol/kg H(2)O (0.381-0.412 Osm/kg). Macromolecules, such as PVP10, Ficoll 70, bovine serum albumin, and skim milk had almost no effect, but compounds with a molecular weight of about 800, such as metrizamide and Nycodenz, had some protective effect. When a raffinose solution was supplemented with 10% metrizamide, resulting in an osmolality of approximately 0.400 Osm/kg, a high survival rate was obtained. Solutions at about 0.400 Osm/kg containing trehalose alone, trehalose + metrizamide, raffinose alone, and raffinose + metrizamide, were all effective for sperm freezing; frozen-thawed sperm could fertilize oocytes, and the resultant embryos could develop to live young after transfer. For freezing mouse spermatozoa, aqueous solutions at approximately 0.400 Osm/kg containing a disaccharide or a trisaccharide seem to be effective.

Chick muscle-derived protein 62: a novel neurite outgrowth promoting protein

A 3.2 kb chick cDNA clone that coded for a novel muscle-derived protein, MDP62, was isolated from a cDNA library of the denervated crus muscles using an antibody which inhibited the neurite (dendritic and axonal processes) outgrowth activity. MDP62 consisted of 539 aa with a calculated molecular mass of 62 k. The predicted protein sequence was hydrophilic and exhibited an extended coiled-coil domain and a leucine zipper motif. A recombinant protein promoted the neurite outgrowth from the cultured chick neurons of the telencephalon in a dose dependent manner. Northern blotting revealed that MDP77 was ubiquitously expressed. In the transfected COS-7 cells with the cDNA of the epitope-tagged MDP62, the expressed protein was detected in the culture medium, suggesting that the MDP62 might be secreted.

Stromal cell-independent differentiation of human cord blood CD34+CD38- lymphohematopoietic progenitors toward B cell lineage

To study the cytokine regulation of early stages of human B-lymphopoiesis, we developed a stroma-free two-step culture system. Single human cord blood CD34+CD38- cells were individually cultured by micromanipulation with interleukin (IL)-3, stem cell factor (SCF), fIt3 ligand (FL), IL-6 and granulocyte colony-stimulating factor (G-CSF). About 10% of the cells formed primary colonies, which were individually tested for myeloid and B-lymphoid potentials by reculturing aliquots of the primary colony cells into secondary myeloid and B-lymphoid cultures. One third of the primary colonies proved capable of differentiation into CD19+IgM+ cells, as well as into myeloid lineage cells. RT-PCR analyses revealed that some cells in the primary culture had already matured to express B cell-specific transcripts. Thus, the combination of IL-3, SCF, FL, IL-6 and G-CSF supported the differentiation of CD34+CD38- lymphohematopoietic progenitors toward B cell lineage in addition to myeloid lineages. Screening of cytokines to identify the minimum requirement of cytokines in the primary culture revealed that IL-3 and SCF were essential and that the addition of FL, and to a lesser extent IL-6 or G-CSF, to the combination of IL3 and SCF remarkably enhanced the primary colony formation and the generation of CD19+ cells in the secondary B-lymphoid culture.

MDP77: A novel neurite-outgrowth-promoting protein predominantly expressed in chick muscles

A 4.7 kb chick cDNA clone that coded for the novel muscle-derived protein, MDP77, was isolated from a cDNA library of the denervated crus muscles using an antibody which inhibited the neurite outgrowth activity. MDP77 consisted of 676 aa with a calculated molecular mass of 77 k. The deduced amino acid sequence exhibited an extended coiled-coil domain and a leucine zipper motif. A recombinant protein promoted the neurite-outgrowth from the cultured chick neurons of the spinal cord in a dose-dependent manner. Northern blotting and in situ hybridization revealed that MDP77 was predominantly expressed in the cardiac and the skeletal muscles. In the COS-7 cells transfected with the cDNA of the epitope-tagged MDP77, the expressed protein was detected in the culture medium, suggesting that the MDP77 was secreted.

Expression of mRNAs of the aquaporin family in mouse oocytes and embryos

The molecular basis of water and cryoprotectant permeability in mammalian oocytes and embryos is poorly understood. Therefore, we investigated the expression of mRNAs of water channel proteins (aquaporins) in mouse oocytes and embryos by RT-PCR. The total RNA of mouse oocytes at metaphase II and embryos at the 4-cell, morula, and blastocyst stages was isolated, reverse-transcribed, and subjected to nested PCR amplification. Aquaporins were expressed in both oocytes and embryos, but the types were different among the developmental stages: aquaporins 3 and 7 were expressed in oocytes and embryos at all stages examined, but aquaporins 8 and 9 were expressed only in blastocysts. On the other hand, aquaporins 1, 2, 4, 5, and 6 were not detected in any of the stages examined. The present study shows for the first time that aquaporins are expressed in mammalian oocytes and embryos. These aquaporins may play a role in water transport and conceivably also in cryoprotectant transport across the plasma membrane in these cells.

Structural analysis of the gene encoding RP58, a sequence-specific transrepressor associated with heterochromatin

RP58, a sequence-specific transcriptional repressor sharing homology with the POZ domain of a number of zinc-finger proteins, is highly synthesized in brain and localized in condensed chromatin regions, suggesting a role in transcriptional repression in the central nervous system. In the present study, genomic clones of the human rp58 gene were isolated to determine the complete genomic organization. Sequence analyses indicated that the human rp58 gene encoding the functional protein is uninterrupted over its entire 4.2 kb length. Comparison of the human and mouse rp58 genes revealed that they share not only a high homology in the amino acid sequences of their encoded proteins, but also a high degree of structural similarity at the genomic level. RT-PCR analysis also demonstrated the existence of an alternatively spliced form of rp58 similar to the previously reported zinc-finger cDNA, C2H2-171. Chromosomal mapping by fluorescence in situ hybridization analysis allowed localization of the rp58 gene to human chromosome 1q44 ter, a genetic region associated with a number of human malignancies and neurological disorders.

a-glucosidase Inhibitors From Paraguayan Natural Medicine, Ñangapiry, The Leaves Of Eugenia Uniflora

The water-soluble extract from a Paraguayan natural medicine, Nangapiry, the leaves of Eugenia uniflora L. (Myrtaceae), which has been used as an antidiabetic agent, was found to show inhibitory activities on the increase of plasma glucose level in the sucrose tolerance test (STT) conducted with mice. The portion adsorbed on a cation exchange resin was also found to inhibit a-glucosidases. From the active portion, two new active compounds named uniflorines A ( 1 ) and B ( 2 ) and known (+)-(3a, 4a, 5ß)-1-methylpiperidine-3, 4, 5-triol ( 3 ) were isolated. The structures of uniflorines A and B were determined as (-)-(1S, 2R, 6S, 7R, 8R, 8aR)-1,2,6,7,8-pentahydroxyindolizidine and (+)-(1S, 2R, 5R, 7R, 8S, 8aS)-1,2,5,7,8-pentahydroxyindolizidine by spectral means, respectively.

Improving effects of the extracts from Eugenia uniflora on hyperglycemia and hypertriglyceridemia in mice

EtOH (70%) extracts from the leaves of Eugenia uniflora were separated into six fractions with different polarity and molecular size, i.e. NP-1-NP-6. In an oral glucose tolerance test, NP-1 and 4 inhibited the increase in plasma glucose level. However, in an intraperitoneal glucose tolerance test, such an inhibitory effect was not seen. Thus, the effects of NP-1 and 4 were apparently due to the inhibition of glucose absorption from the intestine. In a sucrose tolerance test, all fractions inhibited the increase in plasma glucose level. In an oral corn oil tolerance test, NP-3 and 4 showed an inhibitory effect on the increase in plasma triglycerides level. On the other hand, NP-3, 4, 5 and 6 inhibited maltase and sucrase activities and all fractions except for NP-1 showed an inhibitory effect on lipase activity dose-dependently. The inhibition of the increase in plasma glucose level by NP-3, 4, 5 and 6 in the oral sucrose tolerance test and the inhibition of the increase in plasma triglycerides by NP-3 and 4 in the oral corn oil tolerance test were apparently due to the inhibition of the decomposition of carbohydrates and fats in the intestine, respectively.

Regulation of the ryanodine receptor calcium release channel: a molecular complex system

Skeletal muscle contraction is regulated by Ca(2+) released from the sarcoplasmic reticulum (SR). The Ca(2+) release channel in the SR has been identified as the ryanodine receptor (RyR). Recently, it was found that the RyR is a large transmembrane protein that is regulated by many intrinsic factors. In this review, we mainly summarize our experimental results. We will first show that calsequestrin and the DIDS-binding 30-kDa protein work as intrinsic factors and regulate the RyR Ca(2+) release channel. Next, the DIDS-binding 30-kDa protein was identified as the ADT/ATP translocase (AAT) present in mitochondria, based on a cDNA analysis. This result shows that AAT is bifunctional and works as a transporter protein in mitochondria and as a regulator of Ca(2+) release in the SR. From these results, we propose a model in which calsequestrin, the DIDS-binding 30-kDa protein, and junctin form a ternary complex that regulates the RyR Ca(2+) release channel through interactions with triadin.

Possible role of aldosterone and T(3) in development of amiloride-blockable SCC across frog skin in vivo

There are inconsistencies between the in vitro and in vivo effects of thyroid hormone and aldosterone (Aldo) on the development of an amiloride-blockable short-circuit current (SCC) across bullfrog skin [Takada, M., H. Yai, and K. Takayama-Arita. Am. J. Physiol. 268 (Cell Physiol. 37): C218-C226, 1995]. To address this issue, tadpoles were raised in Aldo + T(3). An amiloride-blockable SCC developed across the skin before forelimbs appeared. Noise analysis of the characteristics (single-channel current, blocking and unblocking rate coefficients, and apparent dissociation constant) of this amiloride-blockable Na(+) channel showed that it really was of the adult type. A similar SCC developed at stage XIX in the skin of tadpoles raised with Aldo alone. These results strongly support our hypothesis that the crucial hormone in the development of this SCC is Aldo but that a suppression mechanism attenuates its effect on SCC development until it is removed by the increase in the serum concentration of thyroid hormone (which starts at stages XVIII-XIX in vivo).

[Nationwide survey of allogeneic peripheral blood stem cell transplantation from related donors in Japan: current trends and issues]

In December 1997, we conducted a nationwide survey of cases of primary allogeneic peripheral blood stem cell transplantation (allo-PBSCT) performed in Japan between December 1994 and November 1997 Data was collected on 103 patients with hematologic malignancies, aplastic anemia, or solid tumors. Eighty-seven patients received transplants from HLA-identical siblings, and 16 from HLA-mismatched related donors. Granulocyte-colony stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSC) were collected from donors by 1 to 3 aphereses. Apheresis products contained a median 5.4 (1.0-30.4) x 10(6) CD34 + cells/kg. Most patients were given cyclosporine and methotrexate for graft-versus-host disease (GVHD) prophylaxis. Median days to ANC > 500/microliter and platelets > 50,000/microliter were 13 (7-49) and 16 (10-94), respectively. Grade II-IV acute GVHD developed in 37/99 (37.4%) and chronic GVHD in 59/86 (68.6%) patients. The incidence of treatment-related mortality within 100 days after transplant was 16.1%. Fifty-five patients (59.6%) were alive after a median follow-up of 794 days. More patients and longer follow-up periods will be required to assess the efficacy of allo-PBSCT and evaluate graft-versus-leukemia effect along with the incidence of acute and chronic GVHD.

Synaptic potentiation induced by a protein factor in cultured cerebral neurons

1. We reported in a previous paper that long-lasting enhancement of spontaneous excitatory post synaptic currents (SEPSCs) in cultured chick cerebral neurons was induced by exposure to a conditioned medium (CM) prepared by Mg(2+)-free treatment of neurons. This suggested that the CM contained a diffusible factor(s) for the potentiation. 2. In this paper, the factor(s) was shown to be a protein(s) by heat and trypsin treatment of the CM. 3. The factor induced the potentiation within 5 min, but it was not required for maintenance of increased SEPSCs. 4. The factors in CM induced the potentiation without protein synthesis. 5. Protein synthesis at least in postsynaptic neurons, was indispensable to induce the potentiation by the Mg(2+)-free condition.

Transmission of an azole-resistant isogenic strain of Candida albicans among human immunodeficiency virus-infected family members with oropharyngeal candidiasis

We report transmission of an azole-resistant, isogenic strain of Candida albicans in a human immunodeficiency virus (HIV)-infected family of two children with symptomatic oropharyngeal candidiasis and a mother with asymptomatic colonization over a 5-year period. These findings were confirmed by three different molecular epidemiology methods: interrepeat PCR, Southern hybridization with a C. albicans repetitive element 2 probe, and electrophoretic karyotyping. This study contributes to an evolving understanding of the mode of transmission of C. albicans, particularly in children, and underscores the importance of monitoring specimens from family members of HIV-infected patients.

[A multicenter early phase II study of high-dose chemotherapy with autologous peripheral blood stem cell transplantation for treatment of intermediate-grade non-Hodgkin's lymphoma. Japan Blood Cell Transplantation Study Group]

We conducted a multicenter early phase II study to evaluate the feasibility and therapeutic efficacy of high-dose chemotherapy supported by autologous peripheral blood stem cell transplantation (auto-PBSCT) for the treatment of intermediate grade non-Hodgkin's lymphoma (IG-NHL). High-dose etoposide or cyclophosphamide followed by G-CSF was used for PBSC mobilization, and a sufficient number of CD34+ cells (> 1 x 10(6)/kg) were collected. Out of 81 enrolled patients, 50 received high-dose chemotherapy with auto-PBSCT; Hematologic recovery after transplantation was rapid. The incidence of grade III/IV toxicity (Bearman) was about 6%; treatment-related mortality was 6% (3/50). The Disease-free survival rate for the patients in complete remission who received high-dose chemotherapy with auto-PBSCT was better than that for the patients who were treated with conventional chemotherapy (57% vs 35%). These preliminary results indicated that high-dose chemotherapy with auto-PBSCT is feasible and effective. A prospective randomized phase III clinical trial will be required to assess the efficacy of high-dose chemotherapy with auto-PBSCT as a post-remission therapy for IG-NHL.

Endogenous nerve growth factor increases the sensitivity to bradykinin in small dorsal root ganglion neurons of adjuvant inflamed rats

To examine the cellular mechanisms of hyperalgesia observed in an adjuvant-induced chronic inflammation, the role of nerve growth factor (NGF) in the response to bradykinin (BK) in small neurons from dorsal root ganglia (DRG) was studied via intracellular recordings. After 2 days of cultivation in the absence of NGF, the percentage of neurons from adjuvant-inflamed (AI) rats which were depolarized by BK (53%) was significantly higher than that in neurons from intact rats (13%). This higher percentage in AI rat neurons was significantly reduced after culturing with anti-NGF (17%), but was not influenced by the addition of NGF (57%). The present result demonstrated that sensitivity to BK of DRG neurons from AI rats is increased due to the action of endogenous NGF, suggesting that plastic change in primary afferent neurons caused by NGF may be one of the mechanisms involved in hyperalgesia.

AS-924, a novel orally active bifunctional prodrug of ceftizoxime. Synthesis and relationship between physicochemical properties and oral absorption

Ceftizoxime (CZX), a parenteral cephalosporin, has potent and broad antibacterial activity. To improve its oral absorption, we synthesized a series of monofunctional and bifunctional prodrugs of CZX. In rabbits, urinary recovery after oral administration of CZX was improved by esterification of the carboxyl group at the C-4 position with various lipophilic moieties (monofunctional prodrugs), and was further increased by introduction of a hydrophilic L-alanine to the amino group on the thiazole ring at the C-7 position (bifunctional prodrugs). Least-squares analysis showed good parabolic correlations between log P and urinary recovery for monofunctional and bifunctional prodrugs, respectively. AS-924, a bifunctional prodrug with a pivaloyloxymethyl and L-alanyl moiety had the best balance of lipophilicity and water-solubility for oral absorption among the prodrugs synthesized.

Intraoperative electrooculographic monitoring of oculomotor nerve function during skull base surgery. Technical note

Intraoperative monitoring techniques for protecting the integrity of the oculomotor nerves during skull base surgery have been reported by several investigators, all of which involved the use of electromyographic responses to extraocular muscles. However, these techniques have not yet become popular because of the complexity of the procedures. The authors report an extremely simple and far more reliable technique in which electrooculographic (EOG) monitoring is used. The oculomotor nerves were stimulated with a monopolar electrode during skull base exposure. The polarity of the EOG responses recorded with surface electrodes placed on the skin around the eyeball yielded precise information concerning the location and function of the oculomotor and abducent nerves. In addition, with the aid of continuous EOG monitoring that detected transient changes in the background waves, surgical procedures that might impinge on oculomotor nerve function could be avoided. The present technique has been used in eight patients with skull base tumors and with it, the authors have achieved excellent results.

Restoration of resistance to osmotic swelling of vitrified mouse embryos by short-term culture

In cryopreservation of mammalian embryos, embryos can be injured by osmotic swelling during removal of the cryoprotectant after warming. We have shown that vitrified embryos are more sensitive to osmotic swelling than fresh cells but that sensitivity is reduced or abolished if vitrified cells are cultured for a short period before subjecting them to hypotonic stress. In the present study, we examined the mechanism by which vitrified two-cell mouse embryos regain their resistance to osmotic swelling by culturing the embryos in the presence of various inhibitors before hypotonic treatment. New synthesis of RNA and proteins during culture was not required for regaining resistance to osmotic swelling because actinomycin D and cycloheximide failed to inhibit restoration. Inhibitors of polymerization of microfilaments and microtubules (cytochalasin B and demecolcine, respectively) also did not affect restoration of resistance to osmotic swelling, suggesting that rearrangement or repolymerization of cytoskeletal components is not involved in this process. On the other hand, brefeldin A and concanamycin A, which inhibit intracellular vesicular transport, strongly suppressed restoration of resistance. These results suggest that the intracellular vesicular transport system plays a crucial role in restoration of resistance of vitrified embryos to osmotic swelling during short-term culture.

Dietary effect of conjugated linoleic acid on lipid levels in white adipose tissue of Sprague-Dawley rats

We examined the effect of dietary conjugated linoleic acid (CLA) on lipid parameters in the liver, white adipose tissue (WAT) and brown adipose tissue (BAT) of Sprague-Dawley rats and found that it reduced the levels of triglycerides and non-esterified fatty acid in the liver and WAT without significant change in the BAT lipid levels. These results suggest that CLA has an obesity-preventing action.

A dose-finding study of lenograstim (glycosylated rHuG-CSF) for peripheral blood stem cell mobilization during postoperative adjuvant chemotherapy in patients with breast cancer. Lenograstim/Breast Cancer Study Group

BACKGROUND

The optimum dose of granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell (PBSC) mobilization after disease-oriented, conventional-dose chemotherapy remains unknown.

METHODS

A multicenter dose-finding study of glycosylated G-CSF (lenograstim) for the mobilization of PBSCs following adjuvant CAF chemotherapy (cyclophosphamide, doxorubicin and 5-fluorouracil) was performed in 38 patients with postoperative breast cancer. Each 10, ten and eight patients were sequentially allocated to one of the three dose groups (2, 5 and 10 micrograms/kg, respectively) of lenograstim. Lenograstim was administered subcutaneously (s.c.) daily from day 8 to the day of the last apheresis and CD34+ cells and colony-forming units-granulocyte macrophage (CFU-GMs) in peripheral blood were measured serially. Additionally, 10 patients who received adjuvant CAF chemotherapy alone also participated in the study, as a control.

RESULTS

Lenograstim was well tolerated up to 10 micrograms/kg, except for one patient given 10 micrograms/kg who developed transient grade 3 hepatic enzyme elevation. The peak levels of CD34+ cells and CFU-GMs in peripheral blood showed dose-response relationships. The median peak CD34+ cells for the 0, 2, 5 and 10 micrograms/kg dose groups were 5.4, 34.3, 55.0 and 127.6 cells/microliter, respectively, and those of CFU-GMs for the 0, 2, 5 and 10 micrograms/kg dose groups were 0.01, 0.33, 1.32 and 3.30 CFU-GMs/microliter, respectively.

CONCLUSIONS

Considering the previous reports suggesting that a pre-apheresis number of 40-50 CD34+ cells/microliter in peripheral blood is highly predictive for achievement of more than 2.5 x 10(6) CD34+ cells/kg in a standard apheresis procedure of 10 litres, the optimum dose of lenograstim for PBSC mobilization following CAF chemotherapy in patients with postoperative breast cancer is 5 micrograms/kg/day s.c.

Formation of a major DNA adduct of the mitomycin metabolite 2,7-diaminomitosene in EMT6 mouse mammary tumor cells treated with mitomycin C

Treatment of EMT6 mouse mammary tumor cells with [3H]mitomycin C (MC) results in the formation of six major DNA adducts, as described earlier using an HPLC assay of 3H-labeled products of enzymatic hydrolysis of DNA isolated from MC-treated cells. Four of these adducts were identified as monofunctional and bifunctional guanine-N2 adducts in the minor groove of DNA. In order to establish relationships between individual types of MC-DNA adducts and biological responses it is necessary to identify all of the adducts formed in cells. To this end we have now identified a predominant, previously unknown adduct formed in MC-treated EMT6 cells as a derivative not of MC, but of 2,7-diaminomitosene (2,7-DAM), the major bioreductive metabolite of MC. Rigorous proof demonstrates that it is a DNA major groove, guanine-N7 adduct of 2,7-DAM, linked at C-10 to DNA. The adduct is relatively stable at ambient temperature, but is readily depurinated upon heating. Its isolation from MC-treated cells indicates that MC is reductively metabolized to 2,7-DAM, which then undergoes further reductive activation to alkylate DNA, along with the parent MC. Low MC:DNA ratios were identified as a critical factor promoting 2,7-DAM adduct formation in an in vitro model calf thymus DNA/ MC/reductase model system, as well as in MC-treated EMT6 cells. The 2,7-DAM-guanine-N7 DNA adduct appears to be relatively noncytotoxic, as indicated by the dramatically lower cytotoxicity of 2,7-DAM in comparison with MC in EMT6 cells. Like MC, 2,7-DAM exhibited slightly greater cytotoxicity to cells treated under hypoxic as compared to aerobic conditions. However, 2,7-DAM was markedly less cytotoxic than MC under both aerobic and hypoxic conditions. Thus, metabolic reduction of MC to 2,7-DAM represents a detoxification process. The differential effects of MC-DNA and 2,7-DAM-DNA adducts support the concept that specific structural features of the DNA damage may play a critical role in the cytotoxic response to a DNA-targeted chemotherapeutic agent.