The Ras target AF-6 is a substrate of the fam deubiquitinating enzyme

The Ras target AF-6 has been shown to serve as one of the peripheral components of cell-cell adhesions, and is thought to participate in cell-cell adhesion regulation downstream of Ras. We here purified an AF-6-interacting protein with a molecular mass of approximately 220 kD (p220) to investigate the function of AF-6 at cell-cell adhesions. The peptide sequences of p220 were identical to the amino acid sequences of mouse Fam. Fam is homologous to a deubiquitinating enzyme in Drosophila, the product of the fat facets gene. Recent genetic analyses indicate that the deubiquitinating activity of the fat facets product plays a critical role in controlling the cell fate. We found that Fam accumulated at the cell-cell contact sites of MDCKII cells, but not at free ends of plasma membranes. Fam was partially colocalized with AF-6 and interacted with AF-6 in vivo and in vitro. We also showed that AF-6 was ubiquitinated in intact cells, and that Fam prevented the ubiquitination of AF-6.

Effects of magnesium supplementation in hypertensive patients: assessment by office, home, and ambulatory blood pressures

An increase in magnesium intake has been suggested to lower blood pressure (BP). However, the results of clinical studies are inconsistent. We studied the effects of magnesium supplementation on office, home, and ambulatory BPs in patients with essential hypertension. Sixty untreated or treated patients (34 men and 26 women, aged 33 to 74 years) with office BP >140/90 mm Hg were assigned to an 8-week magnesium supplementation period or an 8-week control period in a randomized crossover design. The subjects were given 20 mmol/d magnesium in the form of magnesium oxide during the intervention period. In the control period, office, home, and average 24-hour BPs (mean+/-SE) were 148.6+/-1.6/90.0+/-0.9, 136.4+/-1.3/86.8+/-0.9, and 133.7+/-1.3/81.0+/-0.8 mmHg, respectively. All of these BPs were significantly lower in the magnesium supplementation period than in the control period, although the differences were small (office, 3.7+/-1.3/1.7+/-0.7 mmHg; home, 2.0+/-0.8/1.4+/-0.6 mmHg; 24-hour, 2.5+/-1.0/1.4+/-0.6 mm Hg). Serum concentration and urinary excretion of magnesium increased significantly with magnesium supplementation. Changes in 24-hour systolic and diastolic BPs were correlated negatively with baseline BP or changes in serum magnesium concentration. These results indicate that magnesium supplementation lowers BP in hypertensive subjects and this effect is greater in subjects with higher BP. Our study supports the usefulness of increasing magnesium intake as a lifestyle modification in the management of hypertension, although its antihypertensive effect may be small.

HLA-DP-associated susceptibility to the optico-spinal form of multiple sclerosis in the Japanese

We studied polymorphism of the HLA-DP gene in 46 patients with optico-spinal form (Asian type) multiple sclerosis (MS) showing recurrent opticomyelitis and 46 patients with Western type MS with disseminated central nervous system involvement. We previously reported a significant association between an HLA-DRB1 *1501-DRB5*0101 haplotype and susceptibility to Western type but not Asian type MS. In the present study, we found that the frequencies of DPA1 *0202 and DPB1 *0501 alleles were significantly increased in patients with Asian type MS, as compared with findings in 92 healthy control subjects (91.3% vs 65.2%, P(corr)<0.05 and 89.1% vs 63.0%, P(corr)<0.05 respectively), but not in Western type MS. Our data provide further evidence that Asian and Western type MS are distinct regarding the immunogenetic background.

Skeletal muscle insulin resistance after trauma: insulin signaling and glucose transport

Surgical trauma induces peripheral insulin resistance; however, the cellular mechanism has not been fully elucidated. We examined the effects of surgical trauma on insulin receptor signaling and glucose transport in skeletal muscle, a tissue that plays a predominant role in maintaining glucose homeostasis. Surgical trauma was induced by intestinal resection in the rat. Receptor phosphorylation was not altered with surgical trauma. Phosphotyrosine-associated phosphatidylinositol (PI) 3-kinase association was increased by 60 and 82% compared with fasted and fed controls, respectively (P < 0. 05). Similar results were observed for insulin receptor substrate-1-associated PI 3-kinase activity. Insulin-stimulated protein kinase B (Akt kinase) phosphorylation was increased by 2.2-fold after surgical trauma (P < 0.05). The hyperphosphorylation of Akt is likely to reflect amplification of PI 3-kinase after insulin stimulation. Submaximal rates of insulin-stimulated 3-O-methylglucose transport were reduced in trauma vs. fasted rats by 51 and 38% for 100 and 200 microU/ml of insulin, respectively (P < 0.05). In conclusion, insulin resistance in skeletal muscle after surgical trauma is associated with reduced glucose transport but not with impaired insulin signaling to PI 3-kinase or its downstream target, Akt. The surgical trauma model presented in this report provides a useful tool to further elucidate the molecular mechanism(s) underlying the development of insulin resistance after surgical trauma.

Comparison of 24-hour blood pressure, heart rate, and autonomic nerve activity in hypertensive patients treated with cilnidipine or nifedipine retard

We compared the effects of cilnidipine and nifedipine retard on 24-h blood pressure (BP), heart rate (HR), and autonomic nerve activity in patients with essential hypertension. Cilnidipine is a novel and unique 1,4-dihydropyridine calcium antagonist that has the L-type and N-type voltage-dependent calcium channel-blocking action. Fourteen hypertensive outpatients (four men and 10 women; aged 64 +/- 2 years, mean +/- SEM) were enrolled in this study. Their ambulatory BP and electrocardiogram were monitored for 24 h at intervals of 30 min with a portable recorder after a 4-week drug-free period, after a 4-week treatment period with cilnidipine (5 or 10 mg once daily), and after a 4-week treatment period with nifedipine retard (10 or 20 mg twice daily). The order of the three periods was randomized. Autonomic nerve activity was evaluated by a power spectral analysis of HR variability, by using the high-frequency (HF) component as an index of parasympathetic nerve activity and the ratio of the low-frequency (LF) component to the HF component (LF/HF) as an index of sympathovagal balance. Cilnidipine and nifedipine retard significantly reduced the 24-h BP of these patients to similar extents (cilnidipine, -11 +/- 3/-6 +/- 1 mm Hg; nifedipine retard, -15 +/- 3/-6 +/- 2 mm Hg). Cilnidipine did not change the 24-h average HR, whereas nifedipine retard significantly increased it (+3.3 +/- 1.4 beats/min; p < 0.05). Nifedipine retard significantly increased the LF/HF ratio in the daytime and the nighttime. Such changes were limited to the daytime in the treatment period with cilnidipine. These results suggest that cilnidipine is effective as a once-daily antihypertensive agent and had less influence on autonomic nervous system and HR than did nifedipine retard.

Effects of amlodipine and nifedipine retard on autonomic nerve activity in hypertensive patients

1. The effects of 1,4-dihydropyridine calcium antagonists with different biological half-lives, amlodipine and nifedipine retard on 24 h blood pressure (BP), heart rate (HR) and autonomic nerve activity in patients with essential hypertension were compared. 2. Twenty patients (six men and 14 women; mean (+/- SEM) age 63 +/- 2 years) with essential hypertension were enrolled in the present study. Their ambulatory BP and electrocardiograms were monitored for 24 h at intervals of 30 min with a portable recorder after a 4 week drug-free period, after a 4 week treatment period with amlodipine (2.5 or 5 mg once daily) and after a 4 week treatment period with nifedipine retard (10 or 20 mg twice daily). The order of the three periods was randomized. Autonomic nerve activity was evaluated by power spectral analysis of HR variability, using the high frequency (HF) component as an index of parasympathetic activity and the ratio of the low frequency (LF) to the HF component as an index of sympathovagal balance. 3. Amlodipine and nifedipine retard significantly lowered the 24 h BP to a similar extent (amlodipine: -12.7 +/- 2.6/-5.6 +/- 1.4 mmHg, P < 0.01/P < 0.01; nifedipine retard: -15.1 +/- 2.1/-6.9 +/- 1.5 mmHg, P < 0.01/P < 0.01). Amlodipine did not change the 24 h average HR, while nifedipine retard significantly increased it (+3.3 +/- 1.2 b.p.m., P < 0.05). Amlodipine also did not change the HF component or the ratio of the LF to the HF component. However, nifedipine retard significantly decreased the HF component (P < 0.01) and increased the ratio of the LF to the HF component (P < 0.05). 4. These results suggest that nifedipine retard caused a decrease in parasympathetic activity and an increase in sympathetic activity with reflex tachycardia in these patients with essential hypertension, while amlodipine did not produce such effects on the autonomic nervous system.

Reduced IL-1 production in adolescents with mite antigen asthma in remission

To determine the immunological mechanisms associated with outgrowing mite antigen-induced bronchial asthma during adolescence, we studied the relationship between clinical status and Dermatophagoides farinae (Df) antigen-induced peripheral cell activation by measuring IL-1alpha and IL-1beta production in patients with bronchial asthma. After antigen-driven restimulation in vitro, there was increased IL-1alpha, IL-1beta production by peripheral blood mononuclear cells (PBMC) from patients with active bronchial asthma, while cellular IL-1alpha, IL-1beta production was reduced in patients with asthma in remission. IL-1alpha and IL-1beta production by PBMC (possibly reflecting airway inflammation) after exposure to Df antigen might be down-regulated in patients outgrowing mite antigen-induced asthma, because lipopolysaccharide-induced IL-1alpha, IL-1beta production (seen in both normal individuals and patients with active asthma) was also reduced when patients were in remission.

Mutational analysis of the N-ras gene in acute lymphoblastic leukemia: a study of 125 Japanese pediatric cases

A point mutation of the N-ras gene is one of the known genetic alterations identified in patients with acute lymphoblastic leukemia (ALL), but its clinical importance is still controversial. Using polymerase chain reactions, we examined codons 12, 13 and 61 of this gene in 125 Japanese childhood ALL patients (64 common-ALL, 22 pre-B-ALL, 33 T-ALL, 2 B-ALL, 3 undifferentiated ALL, and 1 unclassified ALL) including 9 relapsed patients. An N-ras point mutation was observed in 14 (11%) patients (9 common-ALL, 3 T-ALL, and 2 undifferentiated ALL; 13 patients at diagnosis and 1 at relapse). The patients with undifferentiated ALL harbored an N-ras mutation at a significantly higher rate. However, no correlation was found between the presence of an N-ras mutation and sex, age, or white blood count. There was no significant difference in the event-free survival rate between 13 fresh patients with an N-ras mutation and 103 patients with a wild-type configuration. The N-ras mutation was present in about 10% of childhood ALL cases but it did not have a prognostic impact. The sequence analyses revealed that the majority of the patients (13/14) had an N-ras mutation of a G to A transition. This finding was consistent with previous reports on N-ras mutations in acute leukemias in which the incidence of a G to A mutation was significantly higher in ALL than in myeloid malignancies.

Cord blood transplantation from sibling donors in Japan. Report of the national survey

A joint national survey on cord blood transplantation (CBT) was conducted in Japan and 18 sibling CBTs were reported. Diseases of the patients were leukemia (ten), neuroblastoma (one), bone marrow failure (four) and inborn errors of metabolism (three). A volume of 50-141 ml of cord blood containing 27-197 x 10(7) nucleated cells was collected from sibling infants soon after delivery. HLA antigens were identical in 14 and one to three antigens mismatched in four. Engraftment of donor cord blood was achieved in 17 cases. Autologous hematopoiesis was recovered in one case. Days of engraftment were 13-29 days (median 19 days) for neutrophils (500/microliter), 18-67 days (median 30 days) for reticulocytes (2%) and 21-96 days (median 46 days) for platelets (50 x 10(3)/microliter). Acute GVHD was grade 0 in seven cases, grade I in five cases and grade II in one case in HLA-identical pairs, but became grade II in two cases and grade III in two cases in HLA-mismatched pairs. Chronic GVHD of limited type developed in two out of 17 evaluable cases, however both responded to immunosuppressive therapy. Altogether, 14 out of 18 patients are currently surviving 4-27 months following transplantation. Probabilities of overall survival and disease free survival were estimated to be 77.0 and 71.8% using Kaplan-Meier tests. These findings suggest the feasibility of cord blood transplantation from sibling donors and the possibility of unrelated cord blood transplantation. A cord blood banking system is necessary for the universal use of cord blood stem cells from unrelated donors.

Peripheral blood stem cell mobilization with granulocyte colony-stimulating factor and a harvesting procedure in pediatric donors

The safety of injecting healthy donors with granulocyte colony-stimulating factor (G-CSF) has not been established. To evaluate PBSC mobilization and harvesting efficacy in the pediatric population, we compared it with those in adult donors. In this study, we conclude that PBSC mobilization and harvesting protocol in normal pediatric donors can be performed safely and effectively. Considering the lower frequency of side-effects and WBC counts, and G-CSF kinetics, higher dose of G-CSF would be recommended when small children become donors for adult patients.

Multiple sclerosis with mite antigen-specific IgE

The total and mite antigen-specific IgE in the sera were measured in 60 patients with multiple sclerosis (MS) and 40 healthy controls by an enzyme-linked immunosorbent assay using two common mite antigens, Dermatophagoides farinae and Dermatophagoides pteronyssinus, in order to study the role of atopy in MS. Neither the total IgE level nor the frequency of mite antigen-specific IgE differed significantly between the MS patients (mean total IgE 162 U/ml, 42% mite IgE-positive) and healthy controls (mean total IgE 168 U/ml, 35% mite IgE-positive). The MS patients with mite antigen-specific IgE showed a significantly higher level of serum total IgE (mean 293 U/ml, P=0.0005) and a higher frequency of atopic disorders (36%, P=0.0508) than did the MS patients without mite antigen-specific IgE (mean total IgE 68 U/ml, atopic disorders 14%). The former group also showed a significantly higher frequency of male (P=0.0216), a younger age of onset (P=0.0081), a lower expanded disability status scale (EDSS) score (P=0.03) and a lower protein content in the cerebrospinal fluid (CSF) (P=0.0426) than the latter, while the duration of disease and a number of relapses did not differ significantly between the two groups. In addition, the mite IgE-positive MS showed a very low frequency of oligoclonal IgG bands in CSF (4%) and a significantly higher association of HLA-A24 (87.5%) than the healthy controls (45%). Therefore, the presence of IgE response to the mite antigens and atopy appeared to significantly lessen the severity of the disease and the immunologic abnormalities in MS.

Peripheral blood stem cell autografts for the treatment of children over 1 year old with stage IV neuroblastoma: a long-term follow-up

This is the first report of the long-term therapeutic results in 22 children more than 1 year old with stage IV neuroblastoma who were treated with autologous peripheral blood stem cell transplantation (PBSCT). The median age of the patients at PBSCT was 4 years (1 to 10 years) and seven of the 17 patients who were evaluated for N-myc amplification were positive. PBSC were collected by a median of four aphereses per patient. The patients underwent PBSCT from 6 to 21 months after the start of therapy (median 10.5 months) at which time 13 patients were in CR, seven were in PR, and two had refractory disease. Multi-drug therapy using the 'high-MEC' regimen consisting of carboplatinum (400 mg/m2) and VP-16 (200 mg/m2) on days -7 to -4, and melphalan (90 mg/m2) on days -3 and -2, was the primary cytoreductive regimen. The median number of infused MNC and CFU-GM was, respectively, 4.3 x 10(8)/kg and 2.4 x 10(5)/kg. After PBSCT, three patients died of regimen-related toxicities and one patient who was transplanted with refractory disease died of disease progression without any benefit from transplantation. Hematological recovery was evaluated in 21 patients, excluding one early death. The median number of days required to achieve an AGC of >0.5 x 10(9)/l and platelet count of >50 x 10(9)/l were, respectively, 11 and 46. Eleven patients relapsed 3 to 50 months after PBSCT, and currently seven patients (5/13 who were transplanted in CR and 2/7 in PR) are surviving disease-free at 52 to 84 months. Although the retrospective nature of this study and several variables prevent a meaningful analysis, the overall results still support the feasibility of developing a prospective study of PBSCT with a larger number of children with high-risk neuroblastoma.

Acute myelitis with hyperIgEaemia and mite antigen specific IgE: atopic myelitis

An occurrence of acute localised myelitis was recently seen in four adult patients with atopic dermatitis who had hyperIgEaemia and mite antigen specific IgE. The total and mite antigen specific IgE was therefore studied in serum samples from 19 consecutive patients with acute localised myelitis of unknown aetiology, 56 patients with clinically definite multiple sclerosis, and 40 healthy controls. The total IgE concentration was significantly higher in acute localised myelitis (median=360 U/ml) than in multiple sclerosis (median=52 U/ml, p<0.0001) and the controls (median=85 U/ml, p=0.0002). The specific IgE to Dermatophagoides pteronyssinus was found more often in patients with acute localised myelitis (95%) than in patients with multiple sclerosis (34%, p<0.0001) and the controls (35%, p<0.0001) and the specific IgE to Dermatophagoides farinae was similar (acute localised myelitis 79%, multiple sclerosis 29% (p<0.0001), controls 30%, (p=0.0003). Atopic dermatitis coexisted more commonly in patients with acute localised myelitis (37%) than in patients with multiple sclerosis (0%, p<0.0001) and the controls (7.5%, p=0.0089). Therefore, acute localised myelitis with hyperIgEaemia, in which atopy to mite antigens seems to exist, may be a distinct subtype of allergic myelitis-that is, atopic myelitis.

Responses of natriuretic peptides to acute and chronic salt loading in normotensive and hypertensive subjects

Responses of endocrine systems to acute and chronic salt loading were examined in normotensive and hypertensive subjects. In the acute salt load study, isotonic saline (20 ml/kg for 1 h) was intravenously infused in 10 normotensive subjects and 12 patients with essential hypertension. Plasma noradrenaline was suppressed by saline infusion in the normotensive subjects (-19%, p < 0.05), but was not suppressed in the hypertensive patients (-5%, NS). Plasma brain natriuretic peptide concentration was significantly increased in the hypertensive patients (+15%, p<0.05), while it was unchanged in the normotensive subjects. In the chronic salt load study, 9 normotensive subjects and 30 patients with essential hypertension underwent two 7-d periods of 30 and 260 mmol/d sodium intake. On the basis of the blood pressure change, 17 hypertensive patients were classified as salt-resistant and 13 as salt-sensitive. The salt-sensitive hypertensive patients had suppressed plasma renin activity even during low-salt intake. During high salt intake, the plasma noradrenaline concentration failed to decrease in the salt-sensitive hypertensive patients (-6%, NS), whereas it fell significantly in the normotensive subjects (-27%, p < 0.05) and the salt-resistant hypertensive patients (-33%, p < 0.01). The high-salt intake also increased plasma concentrations of brain natriuretic peptide as well as atrial natriuretic peptide in all groups. In the salt-sensitive hypertensive patients, there was a positive correlation between the increase in blood pressure and that in atrial natriuretic peptide (r= 0.84, p< 0.01). These data indicate that brain natriuretic peptide is involved in chronic changes in body fluid volume. In patients with essential hypertension, acute volume expansion also evokes the response of brain natriuretic peptide. Salt-sensitive hypertension seems to be characterized by blunted response of the sympathetic nervous system. In addition, an increase in atrial natriuretic peptide is likely to play an important role in mechanisms counteracting salt-induced elevation of blood pressure.

Effect of oxatomide on T-cell activation and the production of interferon-gamma in mite sensitive asthma

Interleukin-2 responsiveness of lymphocytes induced by Dermatophagoides farinae antigen was suppressed upon exposure to 20 to 2000 ng/ml of oxatomide for 24 h in a dose-related manner in children with mite-sensitive bronchial asthma. Suppression was greater in the plastic-adherent antigen-presenting cells than in the T-cells. Oxatomide suppressed the production of interleukin-1alpha induced by Dermatophagoides farinae antigen in plastic-adherent cells. These results indicate that the target cells of oxatomide are antigen-presenting cells and not T-cells. Oxatomide also suppressed interleukin-2 responsiveness in lymphocytes exposed to purified protein derivative, but not in those exposed to concanavalin A. Unlike its effect on cell proliferation, oxatomide potentiated the Dermatophagoides farinae-induced production of interferon-gamma, which was suppressed by stimulation with Dermatophagoides farinae antigen in lymphocytes from the patients. In contrast, production of interferon-gamma induced by concanavalin A was not affected by this drug. These results indicate that oxatomide suppresses interleukin-2 responsiveness of allergen-activated helper T-cells and increases the production of interferon-gamma induced by Dermatophagoides farinae antigen, without causing cell proliferation.

Total parenteral nutrition on energy metabolism in children undergoing autologous peripheral blood stem cell transplantation

The resting energy expenditure (REE) and the respiratory quotient (RQ) were measured longitudinally using indirect calorimetry to examine the effects of total parenteral nutrition (TPN) on energy metabolism in children undergoing autologous peripheral blood stem cell transplantation (PBSCT). There were six children (two males and four females) and the age ranged from five to 13 years (median, eight yrs). The diagnosis included acute lymphocytic leukemia (ALL; 4), neuroblastoma (NBL; 1) and primitive neuroectodermal tumor (PNET; 1). TPN was started after the patients were stabilized following PBSCT (group A; n = 3) or before the initiation of high-dose cytoreductive chemotherapy (HCC) (group B; n = 3). Duration of HCC before PBSCT was identical between the two groups (six to eight days). Average total calorie and protein intake during HCC was significantly higher for group B than for group A. The %REE, the percentage of REE to the predicted basal energy expenditure (BEE), in group A showed 133 +/- 19%, 129 +/- 14% and 146 +/- 11% during three periods of HCC (days -8 to -1 of PBSCT), bone marrow suppression (days 0 to 11 of PBSCT) and bone marrow recovery (days 12 to 22 of PBSCT), respectively. In contrast, those in group B were 10% to 20% lower than those in group A at all periods. Carbohydrate oxidation rates during HCC in group A were significantly lower than those in group B, and those were not different between both groups during post-PBSCT periods. Fat oxidation rates in both groups were similar at all stages of periods. In contrast, protein degradation rates in group A were significantly higher than those in group B at all stages of the period. From these results, we concluded that commencement of TPN administration prior to HCC in the patients undergoing PBSCT provides beneficial effects to maintain better energy metabolic and nutritional status.

Crystallization and preliminary X-ray diffraction studies of bleomycin-binding protein from bleomycin-producing Streptomyces verticillus

A bleomycin-binding protein (BLMA) produced by bleomycin-producing Streptomyces verticullus was crystallized in a form suitable for X-ray diffraction analysis using the vapor-diffusion method. Crystals were grown at pH 5.7, in 0.2 M NH4 actate and 0.1 M Na acetate, using 30% PEG 4000 as a precipitant. They belong to the orthorhombic system, with space group P21212, cell dimensions a = 54. 90, b = 67.94, c = 35.60 A, and one BLMA molecule in the asymmetric unit. The crystals diffract X-rays well and the diffraction intensity data was collected up to 1.5 A resolution with a merging R value of 0.054 at beamline 6B of the Photon Factory. The diffraction data set is 94% complete.

New consecutive high-dose chemotherapy modality with fractionated blood stem cell support in the treatment of high-risk pediatric solid tumors: a feasibility study

For the treatment of childhood solid tumors, we performed a pilot feasibility study of consecutive high-dose therapies, in which each course was followed by transplantation with granulocyte colony-stimulating factor-mobilized peripheral blood cells which had been separated into CD34-positive and -negative fractions by an Isolex system (Baxter). Positive selection of CD34+ cells has been associated with inevitable cell loss. To overcome this loss, CD34+ cells that had migrated into the negative fraction were saved and used for the first transplant, which was followed by a second transplant after a 3- to 5-month interval. In this phase I feasibility study, the results in six children were evaluated for safety and engraftment. Multi-drug cytoreductive regimens using ranimustine (MCNU), melphalan, thiotepa, carboplatin, cyclophosphamide or VP-16 were comparable between the two transplant procedures in terms of their intensity. The number of CD34+ cells in the 'CD34(+) fraction' was 3.31 x 10(6)/kg (0.63-4.3 x 10(6)/kg), while this number in the 'CD34(-) fraction' could not be evaluated correctly due their scarcity (<0.1%). The median numbers of infused MNC and CFU-GM were, respectively, 4.2 x 10(6)/kg and 1.75 x 10(5)/kg in the CD34(+) fraction, and 4.8 x 10(8)/kg and 3.35 x 10(5)/kg in the CD34(-) fraction. The number of days required to achieve an ANC >0.5 x 10(9)/l and a platelet count >20 x 10(9)/l and >50 x 10(9)/l were, respectively, 14.5, 15.0 and 19.5 in the first transplant with CD34- cells, and 13.5, 18.0 and 25.0 in the second transplant with CD34+ cells, with no essential difference between the two treatments. Although the small number of patients, the variation in clinical status and treatment, and the short follow-up invalidate any evaluation of the therapeutic benefit of this strategy, the encouraging results support the feasibility of this strategy, which enables an escalation of dose intensity with an improved cost/benefit ratio.

Synergistic effect of electric pulses and bleomycin on cultured rabbit subconjunctival fibroblasts

BACKGROUND

The combined effect of electric pulses (EP) and antiproliferative agents on the proliferation of rabbit Tenon's capsule fibroblasts was investigated.

METHODS

Rabbit Tenon's capsule fibroblasts were cultured. Some of these cells were exposed to various intensities of EP alone (500-2500 V/cm). Other cells were then exposed for 30 min to an antiproliferative agent: bleomycin (BLM; 0.0005-50 mumol/l), mitomycin C (MMC; 0.0005-50 mumol/l), 5-fluorouracil (5-FU; 0.05-5000 mumol/l), or streptomycin (SM; 0.0005-50 mumol/l) with or without EP (2000 V/cm, 99 mus, eight pulses). Cell proliferation was assessed by cell counting on day 3 and by a 3H-thymidine uptake assay. DNA fragmentation was assessed by flow-cytometric analysis and agarose gel electrophoresis.

RESULTS

A significant reduction in the cell number was observed only at 2500 V/cm (P < 0.05). BLM, MMC and 5-FU treatment inhibited cell proliferation in a dose-dependent manner either with or without EP (ID50: BLM alone, 0.029 mumol/l; BLM and EP, 0.00022 mumol/l; MMC alone, 41.6 mumol/l; MMC and EP, 27.5 mumol/l; 5-FU alone, 1045 mumol/l; 5-FU and EP, 690.2 mumol/l; P < 0.05). EP treatment induced an inhibitory effect of BLM on cell proliferation which was 100 times more prominent than BLM alone (0.0005 mumol/l of BLM alone 103.4 +/- 4.4%, 0.0005 mumol/l of BLM and EP 26.0 +/- 4.4%; P = 0.021). BLM treatment with EP also augmented the apoptotic-like DNA fragmentation in both a flow-cytometric DNA histogram and agarose gel-electrophoresis.

CONCLUSION

EP treatment enhanced the inhibitory effect of BLM on the cell proliferation of Tenon's capsule fibroblasts of rabbits. The combination of electric pulses and antiproliferative drug treatments may therefore reduce the necessary dose of antiproliferative agents in filtering surgery.

Induction of chronic inflammatory arthropathy and mesenchymal tumors in rats infected with HTLV-I

To compare the pathogenicity of HTLV-I derived from patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP) and that from patients with adult T-cell leukemia (ATL), neonatal WKA rats were inoculated with either an HTLV-I-infected T-cell line (Fuk line) newly established from a HAM/TSP patient or MT-2 derived from a patient with ATL. Of 38 rats, 34 developed mesenchymal tumors (89%) only after 14 months of age, irrespective of the cell lines used. The rats inoculated with the Fuk line developed severe arthritis (27%) and anti-type II collagen antibody (64%), and less frequently, paraparesis (7%). Those inoculated with MT-2 developed paraparesis (23%), but not arthritis. Cyclophosphamide (CY) administration to induce immunosuppression in the Fuk line-inoculated rats increased the frequency of paraparesis (70%), but decreased the frequency of tumors (20%). HTLV-I proviral DNA was found in the spinal cord, sciatic nerves, tumors, and joints, whereas pX mRNA was detected in the sciatic nerves and tumors, but not in the spinal cord and joints. As a result, HTLV-I is considered to facilitate development of both chronic inflammatory arthropathy associated with autoimmunity and mesenchymal tumors in rats by experimental infection, and its pathogenicity is likely to be greatly influenced by the host immune state.

Improved glucose tolerance restores insulin-stimulated Akt kinase activity and glucose transport in skeletal muscle from diabetic Goto-Kakizaki rats

The serine/threonine kinase Akt (protein kinase B [PKB] or related to A and C protein kinase [RAC]) has recently been implicated to play a role in the signaling pathway to glucose transport. However, little is known concerning the regulation of Akt activity in insulin-sensitive tissues such as skeletal muscle. To explore the role of hyperglycemia on Akt kinase activity in skeletal muscle, normal Wistar rats or Goto-Kakizaki (GK) diabetic rats were treated with phlorizin. Phlorizin treatment normalized fasting blood glucose and significantly improved glucose tolerance (P < 0.001) in GK rats, whereas in Wistar rats, the compound had no effect on glucose homeostasis. In soleus muscle from GK rats, maximal insulin-stimulated (120 nmol/l) Akt kinase activity was reduced by 68% (P < 0.01) and glucose transport was decreased by 39% (P < 0.05), compared with Wistar rats. Importantly, the defects at the level of Akt kinase and glucose transport were completely restored by phlorizin treatment. There was no significant difference in Akt kinase protein expression among the three groups. At a submaximal insulin concentration (2.4 nmol/l), activity of Akt kinase and glucose transport were unaltered. In conclusion, improved glucose tolerance in diabetic GK rats by phlorizin treatment fully restored insulin-stimulated activity of Akt kinase and glucose transport. Thus, hyperglycemia may directly contribute to the development of muscle insulin resistance through alterations in insulin action on Akt kinase and glucose transport.

[Intraocular neovascularization]

To investigate the mechanism of intraocular neovascularization, we studied how vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) are expressed in the ocular tissues under hypoxic conditions. Prior to proliferation of vascular endothelial cells resulting in neovascularization, the retinal tissues such as pericytes, retinal glial cells, ganglion cells, and ciliary epithelium react directly to hypoxia expressing VEGF and/or IL-8 and stimulate endothelial cell proliferation in a paracrine manner. We demonstrated that transcription factor activator protein-1 (AP-1) is activated for expression of VEGF messenger ribonuculeic acid (mRNA) and in a similar way nuclear factor kappa B (NF-kappa B) is activated for expression of IL-8 mRNA. However, hypoxia-induced expression of VEGF and/ or IL-8 is only one aspect of the complicated processes in intraocular neovascularization. We hope that further detailed analysis of the mechanism will make it possible to inhibit and treat clinically intraocular neovascularization in the near future.