Binding of benanomicin A to fungal cells in reference to its fungicidal action

An antifungal antibiotic, benanomicin A, binds in the presence of Ca2+ to susceptible fungi and some bacteria, but not to antibiotic-resistant bacteria and mammalian cells. With the susceptible yeast Saccharomyces cerevisiae, benanomicin A binds similarly to whole cells and to protoplasts. Studies using benanomicin A and three structurally related derivatives suggested that a carboxylic acid in the D-alanine moiety and a sugar moiety in the benanomicin A molecule are essential for both binding and antifungal activities against growing S. cerevisiae. An amino substituent on the sugar moiety can be replaced with a hydroxyl group without the loss of activities. Benanomicin A binds to various yeast mannans which differ in glycosidic linkages. These results indicate that binding of benanomicin A to the mannan portion of fungal cells is essential for exertion of the antifungal activity.

Relationship between N-acetyltransferase (NAT) activity and liver protoporphyrin level in experimental porphyria

The results of our previous studies demonstrated that isonicotinic acid hydrazide (INH) can aggravate griseofulvin (GF)-induced protoporphyria in mice. To elucidate this phenomenon, we studied the relationship between liver protoporphyrin (PP) levels and N-acetyltransferase (NAT) activity, which is known to be a major catabolic enzyme of INH metabolism in the liver. The results revealed a significant correlation between liver PP levels and NAT activity in the mice fed 0.1% GF and 0.05% INH. In this group, mice with high NAT activity developed severe protoporphyria. There was no correlation, however, between liver PP levels and NAT activity in the mice fed GF alone or INH alone. The result suggested that INH metabolites formed by NAT enhance the hepatotoxicity of GF in mice.

Novel biochemical diagnostic method for aortic dissection. Results of a prospective study using an immunoassay of smooth muscle myosin heavy chain

BACKGROUND

Aortic dissection is one of the most common aortic catastrophes. Although newer diagnostic methods as exemplified by image diagnostic techniques have greatly improved the diagnosis of aortic dissection, the diagnosis is still frequently missed today because the signs and symptoms of the disease are at times obscure. A reliable biochemical diagnostic method for aortic dissection would be beneficial.

METHODS AND RESULTS

A novel biochemical diagnostic method for diagnosis of aortic dissection was developed that uses an immunoassay of monoclonal antibodies to smooth muscle myosin heavy chain. A prospective study was conducted to ascertain the usefulness of the method in the diagnosis of aortic dissection. Twenty-seven patients with aortic dissection admitted within the first 24 hours after onset were enrolled. Serial assay of serum smooth muscle myosin heavy chain showed significant elevations within the first 24 hours after onset of aortic dissection, with levels exceeding 10 ng/mL, with subsequent rapid reductions. The sensitivity of the assay within the first 12 hours was 90% with a specificity of 97%. Analysis of 65 patients with acute myocardial infarction showed that the method could accurately differentiate myocardial infarction from aortic dissection.

CONCLUSIONS

The immunoassay of serum smooth muscle myosin heavy chain is a rapid and reliable biochemical method in the diagnosis of aortic dissection. The potential use of the method in clinical medicine is promising.

Preferential differentiation of P19 mouse embryonal carcinoma cells into smooth muscle cells. Use of retinoic acid and antisense against the central nervous system-specific POU transcription factor Brn-2

Investigation of the molecular mechanisms that control smooth muscle cell (SMC) development and differentiation is a prerequisite in understanding the regulatory mechanisms of physiological and pathological SMC-associated vascular processes. The pluripotent murine embryonal carcinoma P19 cell, whose developmental potential resembles that of early embryonic cells, can develop into cell types derived from the neuroectoderm, mesoderm, and endoderm. In the present study, we have shown a unique strategy to enhance SMC differentiation in P19 cells. Under chemical induction of high concentrations of retinoic acid (1 micromol/L), P19 cells showed optimum differentiation into SMCs. Because the P19 cells thus induced also showed differentiation into neuronal cells, a strategy to block neuronal lineage differentiation was developed using a stable transformant antisense RNA construct against Brn-2, a neuronal lineage-specific POU-domain transcription factor; thus, by specifically inhibiting neuronal differentiation, enhanced SMC differentiation by P19 cells was attained. SMC expression was confirmed by immunohistochemical staining, RNA analysis (RNase protection assay), and protein analysis (Western blot) using SMC-specific markers (eg, SM1 and calponin) and alpha-smooth muscle actin. Our results show that the pathway of SMC differentiation may provide an in vitro system useful in the investigation of SMC regulatory mechanisms (eg, transcriptional regulation) and in the further understanding of SMC development and differentiation.

Registration of S alleles in Brassica campestris L by the restriction fragment sizes of SLGs

Polymorphism of SLG (the S-locus glycoprotein gene) in Brassica campestris was analyzed by PCR-RFLP using SLG-specific primers. Nucleotide sequences of PCR products from 15 S genotypes were determined in order to characterise the exact DNA fragment sizes detected in the PCR-RFLP analysis. Forty-seven lines homozygous for 27 S-alleles were used as plant material. One combination of primers, PS5 + PS 15, which had a nucleotide sequence specific to a class-I SLG, gave amplification of a single DNA fragment of approximately 1.3kb from the genomic DNA of 15 S genotypes. All the DNA fragments showed different electrophroetic profiles from each other after digestion with MboI or MspI. Different lines having the same S genotype had an identical electrophoretic profile even between the lines collected in Turkey and in Japan. Another class-I SLG-specific primer, PS 18, gave amplification of a 1.3-kb DNA fragment from three other S genotypes in combination with PS 15, and the PCR product also showed polymorphism after cleavage with the restriction endonucleases. Genetic analysis, Southern-hybridization analysis, and determination of the nucleotide sequences of the PCR products suggested that the DNA fragments amplified with these combinations of primers are class-I SLGs. Expected DNA fragment sizes in the present PCR-RFLP condition were calculated from the determined nucleotide sequence of SLG PCR products. A single DNA fragment was also amplified from six S genotypes by PCR with a combination of primers, PS3 + PS21, having a nucleotide sequence specific to a class-II SLG. The amplified DNA showed polymorphisnm after cleavage with restriction endonucleases. The cleaved fragments were detected by Southern-hybridization analysis using a probe of S (5) SLG cDNA, a class-IISLG. Partial sequencing revealed a marked similarity of these amplified DNA fragments to a class-II SLG, demonstrating the presence of class-I and class-II S alleles also in B. campestris. The high SLG polymorphism detected by the present investigation suggests the usefulness of the PCR-RFLP method for the identification of S alleles in breeding lines and for listing S alleles in B. campestris.

Angiotensin I-converting enzyme gene polymorphism and salt sensitivity in essential hypertension

We undertook the present study in 66 Japanese patients with essential hypertension to identify genetic factors associated with salt sensitivity. Patients were classified into salt-sensitive or salt-resistant groups on the basis of changes in their mean blood pressures from a week of a low salt diet (50 mmol/d) to a week of a high salt diet (340 mmol/d). Salt sensitivity and resistance were studied in relation to a 287-bp insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme gene detected by a polymerase chain reaction method and the haptoglobin phenotype determined by polyacrylamide gel electrophoresis. Patients with the angiotensin I-converting enzyme gene genotype II were more apt to be salt sensitive than patients with the ID and DD genotypes, although plasma renin activity was similar in each group. The frequency of the I allele in the salt-sensitive group was significantly higher than that in the salt-resistant group (chi2 = 7.4, odds ratio = 2.78). However, there was no significant relationship between haptoglobin phenotype and salt sensitivity. These data suggest that an I/D polymorphism of the angiotensin I-converting enzyme gene is a genetic factor associated with salt sensitivity of blood pressure independently of plasma renin activity in Japanese patients with essential hypertension.

Opening of Ca(2+)-dependent K+ channels by nordihydroguaiaretic acid in porcine coronary arterial smooth muscle cells

Effects of nordihydroguaiaretic acid (NDGA) on the Ca(2+)-dependent K+ channel (BK channel) were examined by the patch clamp technique in single smooth muscle cells of porcine coronary artery. The open probability of BK channels in inside-out patches increased by about 30 times at the holding potential of 0 mV, when 10 microM NDGA was added to the bathing solution (pCa 7.0). The effect of NDGA was concentration-dependent in the range of 1-100 microM and partly removed by washout. The enhancement of BK channels by NDGA was not observed when the cytosolic Ca2+ concentration was very low (pCa > 8.5). These results clearly indicate that NDGA possesses a BK channel opening property in coronary arterial myocytes.

Renal response to L-arginine in salt-sensitive patients with essential hypertension

This study examined whether disturbances in nitric oxide formation contribute to renal dysfunction in salt-sensitive essential hypertensive patients. We evaluated the effects of intravenous administration of L-arginine (500 mg/kg given over 30 minutes) on systemic and renal hemodynamics in 23 patients with mild essential hypertension during 1 week of a low NaCl diet (50 mmol/d) followed by 1 week of a high NaCl diet (340 mmol/d). Patients were classified as salt sensitive (n=10) or salt resistant (n=13) based on salt-induced changes in their blood pressures. Salt loading increased renal vascular resistance but not renal plasma flow in salt-sensitive patients. The L-arginine-induced renovascular relaxation was significantly reduced by a high NaCl diet (renal vascular resistance: low NaCl -12.4 +/- 2.3% versus high NaCl -7.1 +/- 1.8%, P < .001) in salt-sensitive patients, whereas it was unchanged in salt-resistant patients. The increase in plasma cGMP in response to L-arginine was also reduced by a high NaCl diet in the salt-sensitive patients (low NaCl 49 +/- 7% versus high NaCl 36 +/- 8%, P < .05) but not in the salt-resistant patients (low NaCl 51 +/- 6% versus high NaCl 58 +/- 6%). These findings suggest that NaCl loading in salt-sensitive patients with mild essential hypertension reduces the ability of L-arginine to produce nitric oxide in the endothelium of the renal vasculature.

Analysis of CAG trinucleotide expansion associated with Machado-Joseph disease

There are currently some types of autosomal dominant cerebellar ataxias such as Machado-Joseph disease (MJD), spinocerebellar ataxia types 1-5 (SCA1-5), or hereditary dentatorubropallidoluysian atrophy. It is very important for these ataxias to be clinically differentiated, but that is sometimes difficult. In particular, the differential diagnosis between MJD and SCA1 is thought to be the most difficult. Recently, both MJD and SCA1 have been proven to be related to expansions of CAG trinucleotide in their causative genes. In this study, 20 cases of MJD in 13 unrelated Japanese families were genetically and clinically examined in comparison with 20 cases of age at onset- and duration-matched Japanese SCA1. The CAG repeat number of expanded MJD and SCA1 alleles was 72.2 +/- 3.1 (mean +/- SD, n = 20) and 47.3 +/- 4.4 (n = 20), respectively, and each repeat size was inversely correlated with age at onset in both MJD and SCA1. The repeat number in leukocytes increased from parents to children with acceleration of age at onset (anticipation) in MJD. In MJD, the number of CAG repeats in the expanded allele was lower in sperm than that of leukocytes, but was more in SCA1. However, the number of peaks in the expanded allele was greater in sperm than in leukocytes in both MJD and SCA1 (increased mosaicism level). MJD was clinically characterized by a relatively higher frequency of ocular signs such as eyelid retraction, bulging eyes, ophthalmoparesis, and nystagmus, spasticity in lower limbs, and sensory and urinary disturbances in contrast to the SCA1 patients except for slow eye movement. These results indicate that the expanded CAG repeat and clinical features are correlated in both MJD and SCA1, and MJD can be differentiated from SCA1 by clinical characteristics mentioned above as well as DNA analysis.

Clinical characteristics of familial amyotrophic lateral sclerosis with Cu/Zn superoxide dismutase gene mutations

We report clinical characteristics of familial amyotrophic lateral sclerosis (FALS) with 4 different missense point mutations in exons 2, 4, and 5 of the Cu/Zn superoxide dismutase (SOD) gene, that result in amino acid substitutions of histidine46 by arginine (H46R), leucine84 by valine (L84V), isoleucine104 by phenylalanine (I104F), and valine148 by isoleucine (V148I), in 5 Japanese families. Although features of progressive neurogenic muscular atrophy were common in patients of these families, patients of each family showed characteristic clinical features. FALS patients with the H46R mutation showed a benign clinical course and stereotype progression of muscular weakness and atrophy beginning from the legs. In FALS with the L84V mutation, while the clinical course of the disease was similar, the age at onset was younger in men than women. The patients with I104F showed wide ranges of age at onset and duration with ophthalmoparesis and sensory involvement in one patient. Those with the V148I mutation showed younger age at onset and variable first symptoms within the family. Although lower motor sign was evident in all cases, hyperreflexia varied from 0 to 100% among patients with the different mutations, and the Babinski sign was not observed in any case. Bulbar palsy was frequent with I104F, but not with H46R. SOD activity of the red blood cells was severely reduced with I104F and V148I, but was slightly reduced with H46R. These results suggest that familial ALS with different mutations of the Cu/Zn SOD gene each showed clinical characteristics, and that genetic mutations and clinical features are well correlated in familial ALS.

Identification and characterization of geranylgeraniol kinase and geranylgeranyl phosphate kinase from the Archaebacterium Sulfolobus acidocaldarius

Geranylgeranyl diphosphate is an important precursor of archaebacterial ether-linked lipids, and it has been thought that all of this compound is "de novo" synthesized by geranylgeranyl diphosphate synthase. We studied the phosphorylation of geranylgeraniol, which seems to be related to the salvage pathway of biosynthesis of archaebacterial ether-linked lipids, in the Archaebacterium Sulfolobus acidocaldarius. Activities of geranylgeraniol kinase and geranylgeranyl phosphate kinase were detected in a cell lysate of S. acidocaldarius. The two enzymes were easily separated by ultracentrifugation. The membrane fraction and the cytosolic fraction contained geranylgeraniol kinase activity and geranylgeranyl phosphate kinase activity, respectively. Geranylgeraniol kinase, which requires divalent cation such as Mg2+, Co2+, and Mn2+ and NTP (ATP, GTP, CTP, UTP), catalyzes monophosphorylation of (all-E)-geranylgeraniol to produce geranylgeranyl phosphate. (all-E)-Farnesol, (all-E)-hexaprenol, and (all-E)-octaprenol were also active substrates, though they were less effective than (all-E)-geranylgeraniol. However, neither geraniol nor (22E,6E,10Z,14Z,18Z,22Z,26Z,++ +30Z,34Z,38Z)-undecaprenol was active. This enzyme is extremely thermostable and its pH optimal is between 6.5 and 8.5. The Michaelis constants for (all-E)-geranylgeraniol and ATP are 27 nM and 650 microM, respectively.

Participation of gap-junctional cell communication on the adaptive response in human cells induced by low dose of X-rays

To investigate the radioadaptive response of normal cells to low-dose radiation, we irradiated human embryonic (HE) cells and HeLa cells with low-dose X-rays and examined the changes in sensitivity to subsequent high-dose X-irradiation using the trypan blue dye-exclusion test. When HE cells were irradiated by 200 cGy, the growth ratio of the living cells 5 days after the irradiation decreased to 37% of that of the cells which received no X-irradiation. When the cells received a conditioning irradiation of 10-20 cGy 4 h before the irradiation of 200 cGy, the relative growth ratios increased significantly to 45-53%, and a peak was reached at a conditioning dose of 13 cGy to the cells. This conditioning effect was not observed in LeLa cells. When the HE cells were suspended in a Ca2+ ion-free medium or TPA added to the medium while receiving the conditioning irradiation of 13 cGy, the effect of the conditioning dose was not observed. This indicates that normal cells show an adaptive response to low-dose radiation and become more radioresistant. These results suggest that gap junctional intercellular communication may play a role in radioadaptive responses in human cells.

Dietary NaCl loading increases platelet Ca2+ discharge capacity in salt resistant essential hypertension

To clarify the relationship between cellular Ca2+ handling and salt sensitivity, we evaluated cytosolic free Ca2+ ([Ca2+]i) in fura-2 loaded platelets isolated from 20 inpatients with essential hypertension. They were placed on a low sodium diet (50 mmol/day) for one week, followed by one week on a high sodium diet (340 mmol/day). They were classified into salt-sensitive (SS, n = 8) or salt-resistant (SR, n = 12) based on changes in the mean blood pressure. During the low salt diet, basal [Ca2+]i, thrombin-evoked maximal Ca2+ responses, irrespective of the presence of 1 mM extracellular Ca2+, and ionomycin-sensitive intracellular Ca2+ discharge capacity were similar in salt-sensitive and salt-resistant patients. Platelet basal [Ca2+]i were increased in both groups by salt loading (SS, from 22.0 +/- 1.3 to 27.2 +/- 1.9 nM, p < 0.01; SR, from 20.1 +/- 0.8 to 24.4 +/- 1.3 nM, p < 0.05). The thrombin-evoked maximal Ca2+ responses both in the presence and absence of extracellular Ca2+ were unchanged by high salt intake. The rate constant of decline in Ca2+ after the peak response to thrombin was larger in SR than that in SS during the high salt diet period (SS, 0.004 +/- 0.001 sec-1; SR, 0.043 +/- 0.014 sec-1, p < 0.05). The intracellular Ca2+ discharge capacity was increased by excessive salt intake in the salt-resistant patients but was unchanged in the salt-sensitive patients (SS, from 658.1 +/- 52.8 to 639.6 +/- 91.9 nM; SR, from 690.8 +/- 65.1 to 803.3 +/- 65.1 nM, p < 0.05). An increased intracellular Ca2+ discharge capacity may play, at least in part, a significant role in preventing the elevation of blood pressure after salt loading in salt-resistant patients with essential hypertension.

[Manifestation of nasal allergy in ovalbumin-sensitized mice--as compared with mast cell-deficient mice, determined with an immunosuppressive agent]

We performed general and topical sensitization by ovalbumin in wild type, WBBFI6- +/+ (+/+), mice and mast cell-depleted type, WBBFI6-W/Wv (W/W)v, mice. Although both mice showed almost equal PCA liters, W/Wv mice showed a lower level of antigen-induced eosinophilia, and more significant nasal symptoms and histamine hypersensitivity than +/+ mice. Antigen-induced increased levels of histamine and IL-5 in nasal lavage fluid were noted in +/+ mice. Cyclosporin A pre-treatment inhibited the antigen-induced nasal symptoms, nasal eosinophilia and increased levels of histamine and IL-5 in nasal lavage fluid in the +/+ mice. The PCA titer was not affected by the treatment in either kind of mouse.

Dynamic changes in expression of glutamate transporter mRNAs in developing brain

Developmental changes in gene expression for three glutamate transporter subtypes in the mouse brain were analysed by in situ hybridization. During embryonic stages, GluT-1 and GLT-1 mRNAs were expressed at high levels in the ventricular zone, whereas EAAC1 mRNA was not detected in the zone. In the mantle zone, transcription levels of three transporter mRNAs were low during embryonic stages, and these levels, especially those of the GluT-1 and GLT-1 mRNAs, displayed remarkable increases postnatally to reach maximal levels at 14 days of age. These dynamic developmental regulations suggest that the glutamate transporter not only regulates the excitatory synaptic transmission at mature stages, but might also be intimately involved in the brain development.

A major wheat allergen has a Gln-Gln-Gln-Pro-Pro motif identified as an IgE-binding epitope

The minimum primary structure of the IgE-binding epitope in wheat gluten was determined as Gln-Gln-Gln-Pro-Pro. The N-terminal glutamine and the two proline residues were essential for epitopic function. The occurrence of the second glutamine residue and acetylation of the N-terminal amino group were found to exert some auxiliary functions, whereas only a lesser contribution was expected for the third glutamine residue. It has also been confirmed that acetyl-Gln-Gln-Gln-Pro-Pro bound to wheat-specific IgE antibodies in the sera of patients allergic to wheat, although it did not induce histamine release from the basophils of these patients. Taken together, we concluded that the Gln-Gln-Gln-Pro-Pro motif constituted an IgE-binding rather than immunogenic epitope and also that acetyl-Gln-Gln-Gln-Pro-Pro might act as a hapten capable of binding to specific IgE molecules. The possibility exists that this peptide will have practical application to therapy for or prevention of wheat-sensitive allergy.

Overexpression of MP41 gene in a transformed endothelial cell line correlates with the increased fibronectin expression and a decreased incidence of tumorigenicity

mp41 gene, which was originally identified as a gene regulated by the circadian clock, showed some similarity with yeast cell cycle regulator, CDC25, and its mRNA expression is restricted mainly to non-dividing cell. To elucidate the growth regulatory of mp41, mp41 cDNA was transfected into a transformed human endothelial cell line. All stable mp41 transformants showed increased levels of fibronectin expression and reduced migratory activity in vitro. Although the in vitro growth rate of mp41 transformants and their ability to grow in soft agar were not significantly altered, their tumor formation was suppressed significantly in nude mice. The results imply that mp41 gene overexpression altered the tumorigenicity associated with fibronectin elevation in stable transformation of the transformed endothelial cell line.

Cloning of the cDNA encoding the mouse ATBF1 transcription factor

We have isolated a mouse ATBF1 cDNA which is 12-kb long and capable of encoding a 406-kDa protein containing four homeodomains and 23 zinc-finger motifs. Mouse ATBF1 is 94% homologous to the human ATBF1-A transcription factor. Northern blot and RNase protection analysis showed that levels of ATBF1 transcripts were low in adult mouse tissues, but high in developing brain, consistent with a role for ATBF1 in neuronal differentiation.

Preferential activation of CD4+V beta 5.2/5.3+ intestinal intraepithelial lymphocytes in the inflamed lesions of Crohn's disease

To analyze the nature of intestinal intraepithelial lymphocytes (iIELs) in inflammatory intestinal disease, we established T cell lines of iIELs isolated from endoscopic biopsied ileal and colonic mucosa of Crohn's disease patients. Seven T cell lines from the inflamed terminal ileum of 13 patients, but none of 16 T cell lines from normal terminal ileum, have shown a deviation of T cell receptor variable region gene usage and were enriched in the proportion of CD4+V beta 5.2/5.3+ cells. CD4+V beta 5.2/5.3+ cells in the T cell lines were not increased after stimulation with purified protein derivatives or 65-kDa heat-shock protein but significantly increased after stimulation with staphylococcal enterotoxins C1 and D. Those cells showed increased cytolytic activity against target cells cross-linked by anti-V beta 5.2/5.3 and produced a large amount of interferon-gamma. These results indicated that CD4+V beta 5.2/5.3+ iIELs were preferentially activated in the inflamed lesions of Crohn's disease and may play a possible role in the triggering and progression of human inflammatory intestinal disease.

Changes in GABAA receptor function and cross-tolerance to ethanol in diazepam-dependent rats

Changes in gamma-aminobutyric acidA (GABAA) receptor function and their relation to cross-tolerance to ethanol (EtOH) were studied in diazepam (DZP)-dependent rats. Physical dependence on DZP was induced in male Fischer rats by using the drug-admixed food method. The 38Cl- influx into cerebral cortical synaptoneurosomes induced by 10 microM GABA in DZP-withdrawn rats was significantly increased, compared with control and DZP-tolerant rats. Although enhancement of GABA-dependent 38Cl- influx by the addition of EtOH and flunitrazepam (FZ) was recognized in the control, there was no such effect of EtOH or FZ in the DZP-tolerant animals. On the other hand, GABA-dependent 38Cl- influx was enhanced by FZ in the withdrawn group. The addition of picrotoxin and bicuculline inhibited GABA-dependent 38Cl- influx in each group. The stimulatory effect of FZ on GABA-dependent 38Cl- influx was inhibited by the addition of Ro 15-1788 in the control group. However, such an inhibitory effect was not observed in the withdrawn group. The antagonistic effect of Ro 15-4513 on EtOH stimulation of GABA-dependent 38Cl- influx observed in the control was not recognized in the withdrawn group. In a [3H]FZ assay of binding to benzodiazepine (BZ) receptors, Bmax values were significantly increased in DZP-withdrawn animals, but decreased in the DZP-tolerant group, compared with the control. When [3H]muscimol binding was examined, the Kd of high-affinity sites of the GABAA receptor in withdrawn rats was significantly lower than in the control. In low-affinity binding sites, the values of Kd and Bmax were significantly decreased, compared with those in the control. The present study indicates that GABAergic transmission involving the regulation of GABA-dependent chloride channels is altered in DZP-dependent rats. Alterations of the GABAA/BZ/chloride channel complex function may be related to the cross-tolerance between BZ and EtOH.

Angiographic assessment of the stretch-recoil-gain relation after balloon coarctation angioplasty and its relation to late restenosis

The effects of stretch and immediate recoil after balloon angioplasty were evaluated in 21 patients with coarctation of the aorta who underwent balloon coarctation angioplasty. A total of 28 procedures were performed in these patients, who ranged in age from 1 month to 17 years with a mean of 4.3 years. The systolic pressure gradient and coarcted diameter changed significantly from 42 +/- 22 to 14 +/- 9 mmHg (P < 0.0001) and from 4.0 +/- 1.7 to 6.1 +/- 2.0 mm (P < 0.001), respectively. Immediate recoil was responsible for the loss of 33% of the potentially achievable coarcted dimension. Recoil was determined mainly by the degree of arterial stretch. Gain increased exponentially with an increase in stretch. There was a narrow range of % stretch (60-80%) within which an effective diameter gain could be obtained. Both gain and stretch were the best predictors for late restenosis: patients with a larger immediate gain and stretch developed more restenosis. These results suggest that the stretch-recoil-gain relationship may be clinically important for evaluating the best predictor of late restenosis after balloon coarctation angioplasty.

Targeting chemotherapy for malignant brain tumor using thermosensitive liposome and localized hyperthermia

Thermosensitive liposomes are microscopic vesicles that can contain drugs and release them effectively in response to hyperthermia. To deliver an antitumor drug specifically to brain tumor, the authors used thermosensitive liposomes containing cis-diamminedichloroplatinum (CDDP) in conjunction with localized brain heating. The authors then investigated the antitumor effect on rat malignant glioma. Rous sarcoma virus-induced malignant glioma cells were transplanted into the brains of Fisher rats. Ten days after tumor inoculation, the rats were assigned to one of six treatment groups: control, free CDDP, hyperthermia, free CDDP + hyperthermia, liposomes containing CDDP (CDDP-liposome), and CDDP-liposome + hyperthermia. Liposomes containing CDDP or free CDDP were injected via the tail vein. Brain tumor heating was administered by means of a radiofrequency antenna designed at our institute. The rats treated with CDDP-liposome + hyperthermia had the longest survival time and the tumor CDDP level of this group was the highest when compared to the other groups. Histopathological examination showed that tumor cells were necrotized but surrounding normal brain tissue remained undamaged. On the basis of these findings we suggest that the combination of thermosensitive liposome and localized hyperthermia may better focus antitumor drugs to the tumor, providing a significantly greater antitumor effect.

Molecular analysis of a series of alleles in humans with reduced activity at the triosephosphate isomerase locus

Individuals with 50% of expected triosephosphate isomerase (TPI) enzyme activity have been previously identified in families during the screening of approximately 2,000 newborn children for quantitative variation in activity of 12 erythrocyte enzymes. The frequency of the trait was 9/1,713 individuals in the Caucasian population and 7/168 individuals among the African-American population studied. Genetic transmission of the trait was confirmed in all families. The frequency of the presumptive deficiency allele(s) at the TPI locus was greater than expected, given the reported incidence of clinical TPI deficiency. We report the molecular characterization of the variant alleles from seven African-American and three Caucasian individuals in this group of unrelated individuals. Three amino acid substitutions--a Gly-->Ala substitution at residue 72, a Val-->Met at residue 154, and a previously described Glu-->Asp substitution at residue 104--were identified in the Caucasian individuals. The substitutions occur at residues that are not directly involved in the active site but are highly conserved through evolutionary time, suggesting important roles for these residues in maintenance of subunit structure and conformation. The variant allele in the seven African-American individuals had nucleotide changes at positions -8 and -5 (5' of) from the transcription-initiation site. In three of these individuals, an additional T-->G substitution was detected in a TATA box-like sequence located 24 nucleotides 5' of the transcription-initiation site and on the same chromosome as the -5/-8 substitutions. Thus, molecular alterations at the TPI locus were detected in 10 unrelated individuals in whom segregation of a phenotype of reduced TPI activity previously had been identified.

A reproducible assay of polymerase chain reaction to detect trinucleotide repeat expansion of Huntington's disease and senile chorea

A simple and reproducible method of polymerase chain reaction (PCR) assay was established to detect trinucleotide repeat expansion for Huntington's disease (HD) using a new DNA polymerase and buffer system. The system consists of an extremely heat stable DNA polymerase (Pfu), and a buffer supplemented with ammonium sulfate and dimethyl sulfoxide. Previous methods to amplify expanded alleles for HD have been very complex in PCR conditions, but the reproducibility was sometimes very low because of repetitive sequences around the primer sequences. With the present method, strong bands for the disease alleles were reproducibly visible in a conventional agarose gel stained with ethidium bromide without using isotopes. Three cases with sporadic HD and a case with senile chorea showed expanded alleles for HD with smaller sizes of the expansion than cases with typical HD. These results showed that the present method provides a simple and reproducible way to detect HD allele, and some cases with sporadic HD and senile chorea had expanded HD alleles.