Effects of Isoquinolinesulphonamide Compounds on Multidrug-resistant P388 Cells

Abstract— The effects of eight isoquinolinesulphonamide compounds on resistance to vinblastine in adriamycin-resistant mouse leukaemia cells (P388/ADR) which overexpress the relative molecular weight (M_r) 140 kDa P-glycoprotein in the plasma membrane were investigated. N-[2-(Methylamino)ethyl]-5-isoquinolinesulphonamide (H-8) and N-(2-aminoethyl)-5-isoquinolinesulphonamide (H-9) did not reverse vinblastine resistance. N-[2-[N-[3-(4-Chlorophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulphonamide (H-86) and N-[2-[N-[3-(4-chlorophenyl)-1-methyl-2-propenyl]amino]ethyl]-5-isoquinolinesulphonamide (H-87) caused accumulation of intracellular vinblastine and inhibition of vinblastine efflux from the cells and reversed the resistance. Addition of an aminoethyl group to the nitrogen atom of the sulphonamide group (W-66) or a formyl group at the terminal amino group (H-85) of H-86 reduced those activities. Conversion of the chlorophenyl group of H-87 to pyridinyl (H-31) or furanyl (H-34) markedly decreased activities against the drug resistance. The activity against vinblastine accumulation closely correlated with the apparent partition coefficient of compounds. These compounds dose-dependently inhibited photoaffinity labelling of a photosensitive analogue of vinblastine, N-(p-azido-(3-[¹²⁵I])salicyl)-N′-β-aminoethylvindesine ([¹²⁵I]NASV), and there was a good correlation between inhibition of [¹²⁵I]NASV-photolabelling and hydrophobicity. Although these isoquinolinesulphonamides inhibited protein kinase A with different magnitudes, this activity did not correlate with the effect on the drug resistance. These results indicate that isoquinolinesulphonamide compounds with a hydrophobic group interact with antitumour drugs on P-glycoprotein and reverse multidrug resistance without involvement of their activity on protein kinase A.     

Nucleotide and actin binding properties of the isolated motor domain from Dictyostelium discoideum myosin

Nucleotide and actin binding properties of the truncated myosin head (S1dC) from Dictyostelium myosin II were studied in solution using rabbit skeletal myosin subfragment 1 as a reference material. S1dC and subfragment 1 had similar affinities for ADP analogues, ɛADP and TNP-ADP. The complexes of ɛADP and BeF_x or AlF₄ ^- were less stable with S1dC than with subfragment 1. Stern-Volmer constants for acrylamide quenching of S1dC complexes with ɛADP, ɛADP·AlF ₄ ^- and ɛADP.BeF_x were 2.6, 2.9 and 2.2 M^-1, respectively. The corresponding values for subfragment 1 were 2.6, 1.5 and 1.1 M^-1. The environment of the nucleotide binding site was probed by using a hydrophobic fluorescent probe, PPBA. PPBA was a competitive inhibitor of S1dC Ca²⁺-ATPase (K_i = 1.6 μm). The binding of nucleotides to subfragment 1 enhanced PPBA fluorescence and caused blue shifts in the wavelength of its maximum emission in the order: ATP ≈ ADP·AlF^4- ≈ ADP·BeF_x > ATPSγS > ADP > PP_i. In the case of S1dC, the effects of different nucleotides were smaller and indistinguishable from each other. S1dC bound actin tighter than S1 (K_d = 7 nm and 60 nm, respectively). The actin activated MgATPase activity of S1dC varied between preparations, and the V_max and K_m values ranged between 3 and 7 s^-1 and 60 and 190 μm, respectively. S1dC showed lower structural stability than S1 as revealed by their thermal inactivations at 35° C. These results show that the nucleotide and actin binding of S1dC and subfragment 1 are similar but there are some differences in nucleotide and phosphate analogue-induced changes and the communication between the nucleotide and actin binding sites in these proteins This revised version was published online in July 2006 with corrections to the Cover Date.     

Cyclophosphamide therapy for pure red cell aplasia associated with granular lymphocyte-proliferative disorders

Granular lymphocytes have been characterized as cells with azurophilic granules in the cytoplasm. Patients with increased numbers of granular lymphocytes are designated as granular lymphocyte-proliferative disorders (GLPDs). A variety of haematological abnormalities are associated with T-cell-lineage GLPD. Among these, pure red cell aplasia is frequent, and adequate therapy is required. Seven patients with pure red cell aplasia, or a related condition complicating T-cell-lineage GLPD, were entered into this study. Cyclophosphamide was initiated at a daily oral dose of 100 mg. After 2 weeks the dose was reduced to 50 mg/d, and maintained at that dose. Cyclophosphamide was administered until the lymphocyte count was <1 ×10⁹ l and T-cell receptor-β gene analysis was used to monitor the response to treatment. All the patients were successfully treated, irrespective of their former treatment. Clinical remission was associated with the disappearance of the abnormal granular lymphocyte clone, as detected by Southern blot hybridization analysis. Therapeutic responses began after 8 weeks, and clinical complete remissions were obtained after 6 months. Oral cyclophosphamide monotherapy can successfully treat the pure red cell aplasia associated with T-cell-lineage GLPD.     

Diastolic Mitral Regurgitation in Patients with First-Degree Atrioventricular Block

Diastolic mitral regurgitation has been observed in patients with DDD pacemakers when the atrioventricular (AV) delay was prolonged. However, diastolic mitral regurgitation associated with first-degree AV block has not been fully studied. We examined transmitral blood flow in 24 patients with first-degree AV block and normal cardiac function (ages 35.3 ± 17.4 years), and in nine patients with DDD pacemakers and normal cardiac function (ages 73.1 ± 8.1 years), using pulsed Doppler echocardiography. Diastolic mitral regurgitation was observed in 19 of 24 patients with first-degree AV block. Although PQ interval was shortened from 0.32 ± 0.06 to 0.20 ± 0.05 seconds (P < 0.01) after 1 mg atropine sulfate IV, the interval between P wave (ECG) and the beginning of diastolic mitral regurgitation did not change, while the duration of diastolic mitral regurgitation was shortened from 0.15 ± 0.03 to 0.05 ± 0.03 seconds (P < 0.01). There was a significant correlation between changes in PQ interval and changes in the duration of diastolic mitral regurgifation (r = 0.92, P < 0.001). Although cardiac output (3.9 ± 0.05 L/min) and pulmonary capillary wedge pressure (5.1 ± 1.5 mmHg) were normal in all patients with pacemakers, diastolic mitral regurgitation was observed when the AV delay was prolonged. The critical PQ interval for the appearance of diastolic mitral regurgitation was 0.23 ± 0.01 seconds. In patients with prolonged PQ intervals, delayed ventricular contraction following atrial contraction may be associated with mitral regurgitation in the presence of a reversed AV pressure gradient. The results of this study suggest that diastolic mitral regurgitation occurs not only in patients with DDD pacemakers, but also with AAIR pacemakers when the PQ interval is prolonged. The occurrence of diastolic mitral regurgitation is associated with the pacing mode or the setting of AV delay.     

Synthesis and stabilization of amino and carboxy terminal constrained collagenous peptides

Short collagenous peptides cross-linked at their amino and carboxy termini with Lys-Lys-dimer template(s) were synthesized, and the effect of the cross-linking on their stabilities was investigated by thermal denaturation experiments. Two chemoselective ligations were used for the construction of the amino and the carboxy cross-linked peptides. The thermal transition temperature (T_m) and the standard free energies (ΔG°) of the cross-linked collagenous peptides increased, and the thermal stabilization effect corresponded to an elongation by two units of the Gly-Pro-Hyp triad. The van't Hoff enthalpy (ΔH°) and the entropy (ΔS°) values of the cross-linked peptides increased with chain elongation, although the increments were smaller than those of the linear peptides. When the same chain lengths were compared, the ΔH° was increased and the ΔS° was nearly the same or increased by the cross-linking. These results suggest that the cross-linking of the collagenous peptides with the Lys-Lys-dimer template(s) for stabilization contributes to the enthalpic effect, rather than the entropic effect.     

Acquired total immunoglobulin G deficiency in a patient with primary biliary cirrhosis

Abstract. A 38-year-old Japanese woman was hospitalized for susceptibility to respiratory tract infections. Clinical examinations revealed asymptomatic primary cholestasis, abnormally elevated immunoglobulin M (IgM) and antimitochondrial antibody, being consistent with asymptomatic primary biliary cirrhosis. Three years later her serum immunoglobulin G (IgG) decreased remarkably, whereas other immunoglobulins were unchanged. Immunological examinations on the peripheral blood lymphocytes demonstrated spontaneous over-synthesis of serum IgM and decreased synthesis of IgG due to abnormal function of both T and B cells. Our case suggests a new possible association between primary biliary cirrhosis and IgG deficiency.     

Magnetic resonance imaging study of the brain in aged volunteers: T2 high intensity lesions and higher order cortical function

Abstract The aims of the present study were to clarify the findings of magnetic resonance imaging (MRI) in the aging brain, and to relate the MRI findings to higher order cortical function. A total of 118 healthy aged volunteers (41 men, 77 women) underwent cranial MRI electroencephalography (EEG), Benton visual retention test (BVRT) and interview. The subjects had no past history or clinical evidence of cerebrovascular disorder, head trauma or dementia and were living at home without any difficulty. The majority of the subjects have participated in this series of studies since 1982. Using a 1.5 T superconductive MR instrument, T1-weighted, proton density and T2-weighted images were obtained. The MRI data were rated visually by regarding 12 items according to fixed criteria. T2 high signal intensity (T2HSI) lesions were found in 69.5% of subjects, the prevalence of which increased with age. T2HSI lesions were most frequently found in the basal ganglia (61.9%), followed by the thalamus (39.0%), parietal lobe (37.0%), temporal lobe (12.7%) and pons (8.5%). Among these lesions, lacunar infarction showed low signal intensity in T1-weighted images and was found in 24.6% of subjects, the prevalence also increasing with age. These findings, including brain atrophy determined according to similar criteria, were correlated closely with the subjects' age. The results of BVRT showed a close relation with T2HSI, suggesting that T2HSI may influence cognitive function. When the subjects were classified according to the presence of T2HSI, lacunar infarction and EEG abnormalities, brain atrophy was significantly milder in a group of subjects with T2HSI(-), lacunar infarction(-) and normal EEG than in the other groups. This suggests that changes seemingly representing physiological aging may be promoted by another pathological which also exerts influences on higher order cerebral function.     

Non-existence of a positive correlation between urinary levels of α1 -microglobulin and ulinastatin in patients with Parkinson's disease

Urinary levels of a,-microglobulin (αlM) and of ulinastatin (UT) and the αlM/UT ratio did not differ significantly between age-matched controls and patients with Parkinson's disease, and among subdivided groups based on Yahr's stages in Parkinson's disease. Furthermore, these indexes did not correlate with Yahr's stages. Although αlM and UT levels did not correlate in patients with Parkinson's disease, a positive correlation was observed in the control group. The non-existence of a positive correlation between αlM and UT levels distinguishes Parkinson's disease from other neuropsychiatric diseases such as dementia (Alzheimer-type and vascular dementia), schizophrenia and mood disorder.     

Effectiveness of prosthetic mandibular advancement for obstructive sleep apnea:Analysis by sleep position

Abstract Fifteen patients with obstructive sleep apnea were treated using prosthetic mandibular advancement (PMA). Each patient was evaluated in the supine and lateral decubitus positions with and without PMA. After PMA treatment, the mean intraesophageal pressure (Peso) in the supine position improved from -42.6 to -27.3 cmH₂O and the mean apnea + hypopnea index (AHI) decreased from 48.8/h to 23.7/h. The mean Peso in the lateral decubitus position improved from -27.9 to -18.6 cmH₂O and the mean AHI decreased from 9.6/h to 6.6/h. With PMA, respiratory disturbance during sleep further improved by changing the body position from the supine to lateral decubitus position.     

Composite wall-to-wall polymerization contraction in dentin cavities treated with various bonding agents

Abstract – Extracted human teeth are frequently used in studies on bonding of composites to dentin. However, little is known about the effect of storing conditions on the results recorded. The purpose of the present work was to measure the wall-to-wall polymerization contraction of a light-cured composite material with and without the use of five different dentin bonding agents in cylindrical dentin cavities prepared in extracted human teeth, either fresh or after storing for up to 4 wk in four different media. No effect of the storing conditions on the width of contraction gaps could be demonstrated when the teeth were stored either in tap water or in a 1.0% aqueous chloramine solution. Aqueous solutions of either 0.1% benzalkonium chloride or 0.9% sodium chloride did occasionally affect the size of the contraction gap.