Differences in dinucleotide frequencies of human, yeast, and Escherichia coli genes

Nucleotide sequences coding proteins in human, yeast and Escherichia coli genes were analyzed in terms of dinucleotide occurrences. Every gene is plotted as a point in the dinucleotide space, which is spanned by 16 axes corresponding to the 16 components of the dinucleotide. The metric unit in the space is defined using the log-odds ratio of dinucleotide occurrences in a gene. The distribution of points showed that genes from the same organism are clustered in the space. The clusters of human and E. coli are completely separated, and the yeast cluster sits between, implying that individual genes are classified into the three sources from their location. In fact, they could be identified with accuracy of 90%, using the DNA data alone. Even genes encoding homologous proteins belonging to the same protein superfamily were discriminated by the DNA data, and were correctly identified into their sources with the same accuracy as above. DNA sequences of non-coding regions, including human introns, as well as human genes of GC-rich and GC-poor types, were also analyzed in the same manner. The most significant finding is that human genomic DNA sequences, including genes and introns together, exhibit the largest deviation of dinucleotide occurrence from the random expectation. Possible origins for this phenomenon are discussed.

A bag carrier for continuous intravenous hyperalimentation

We designed a new bag-carrier device system for continuous intravenous hyperalimentation. The patient carries it on his shoulder and can both walk up and down stairs and go out. The use of this device is simple and easy, and was found to increase the patient's opportunity to engage in physical activity.

Mutation of the cys-9 gene, which encodes thioredoxin reductase, affects the circadian conidiation rhythm in Neurospora crassa

Ten cysteine auxotrophs of Neurospora crassa were examined with regard to the period lengths of their circadian conidiation rhythms. One of the these cysteine auxotrophs, cys-9, showed dramatic changes in the circadian conidiation rhythm. At 10 microM methionine, the cys-9 mutant had a period length that was 5 hr shorter than that of the wild-type strain during the first 3 days after transfer to continuous darkness. At this concentration of methionine, the period length was unstable after the fourth day and varied widely from 11 to 31 hr. In contrast, other cysteine auxotrophs did not show such instability of the period length at any of the concentrations of methionine tested. Furthermore, only the cys-9 mutant exhibited partial loss of the capacity for temperature compensation of the period length. With regard to cold-induced phase-shifting of the circadian conidiation rhythm, the cys-9 mutant was more sensitive than the wild-type strain to low temperature. The cys-9+ gene was cloned and was found to encode NADPH-dependent thioredoxin reductase. These results indicate that mutation of the gene for thioredoxin reductase results in abnormal expression of the circadian conidiation rhythm in N. crassa.

Anti-human immunodeficiency virus activity of oligosaccharides from rooibos tea (Aspalathus linearis) extracts in vitro

The active substances, acid polysaccharides, were extracted with 1% sodium hydroxide from the leaves of rooibos tea (Aspalathus linearis), Du Zhong Cha (Eucommia ulmoides Oliv.) and Japanese tea leaves (Camellia sinensis var. sinensis). The alkaline extracts of Rooibos tea and Du-Zhong tea leaves, but not Japanese tea leaves suppressed the HIV-induced cytopathicity using HIV (HTLV-III) infected MT-4 cells, having extremely low cytotoxicity: Its 50% effective concentration (EC50) was 12-67 micrograms/mL, white 50% cytotoxic concentration (CC50) was higher than 1.0 mg/mL. The active substances were purified with ethanol precipitation. The substances were composed of 27% of reducing sugar, 46% of neutral sugars and 22% of uronic acid. A LD50 of the alkaline extracts from rooibos tea was higher than 1.2 g/kg body weight. Acid degradated substances composed of disaccharides and trisaccharides, were also suppressed the HIV-induced cytopathicity. From these results, it is probable that acid polysaccharides from rooibos tea were extremely safe, and that HIV infection may be suppressed by daily intake of the alkaline extracts of rooibos tea and Du-Zhong tea.

Pharmacodynamics and pharmacokinetics of a 72-hour infusion of 9-aminocamptothecin in adult cancer patients

PURPOSE

To investigate the pharmacokinetics and pharmacodynamics of 9-aminocamptothecin (9-AC) infused over 72 hours at doses of 5 to 74 micrograms/m2/h.

PATIENTS AND METHODS

9-AC lactone and total (lactone plus carboxylate) plasma concentrations were measured in 44 patients with solid tumors using a high-performance liquid chromatography (HPLC) assay. Fifteen patients underwent extended pharmacokinetic sampling to determine the distribution and elimination kinetics of 9-AC.

RESULTS

At steady-state, 8.7% +/- 4.7% (mean +/- SD) of the total drug circulated in plasma as the active 9-AC lactone. Clearance of 9-AC lactone was uniform (24.5 +/- 7.3 L/h/m2) over the entire dose range examined; however, total 9-AC clearance was nonlinear and increased at higher dose levels. In 15 patients treated at dose levels > or = 47 micrograms/m2/h, the volume of distribution at steady-state for 9-AC lactone was 195 +/- 114 L/m2 and for total 9-AC it was 23.6 +/- 10.6 L/m2. The elimination half-life was 4.47 +/- 0.53 hours for 9-AC lactone and 8.38 +/- 2.10 hours for total 9-AC. In pharmacodynamic studies, dose-limiting neutropenia correlated with steady-state lactone concentrations (Css) R2 = .77) and drug dose (R2 = .71).

CONCLUSION

Plasma 9-AC concentrations rapidly declined to low levels following the end of a 72-hour infusion and the mean fraction of total 9-AC circulating in plasma as the active lactone was less than 10%. The pharmacokinetics of 9-AC may have a great impact on its clinical activity and should be considered in the design of future clinical trials of this topoisomerase I inhibitor.

Lecithinized superoxide dismutase: an inhibitor of human immunodeficiency virus replication

Superoxide dismutase (SOD) is an enzyme used in the treatment of oxygen radical-related diseases. Lecithinization of SOD enhances its pharmacological activity. Lecithinized SOD (PC-SOD) inhibits human immunodeficiency virus (HIV) types 1 and 2 in MT-4 cells. HIV-1-infected MT-4 cells were cultured for 5 days in the presence of PC-SOD, at various concentrations. In an MTT assay, reverse transcriptase (RT) activity of the cell extract and p24 antigen production were measured. Untreated, HIV-1-infected MT-4 cells served as control. PC-SOD inhibited viral replication most effectively at 2500 U/ml, a concentration that did not affect cell viability, with an EC50 value of 718 U/ml. PC-SOD treatment inhibited RT activity and p24 production in a dose-dependent manner. Western blot analysis of the HIV-1-infected MT-4 cells treated with PC-SOD at 2500 U/ml did not detect any expression of viral proteins. Failure to inhibit virus adsorption, proviral DNA and mRNA synthesis, and RT and proteinase enzyme activity suggests that the mechanism of action of PC-SOD is entirely different from those of the currently available anti-HIV drugs. PC-SOD shows synergistic interaction with AZT, ddI, ddC, KNI-272, and dextran sulfate. PC-SOD also inhibited the oxidative stress-induced depletion of sulfhydryls, which are the cause of diminished antioxidant defenses in HIV-infected patients.

Regulation by interleukin-10 and interleukin-4 of cyclooxygenase-2 expression in human neutrophils

Neutrophils are important effector cells of acute inflammation because of their potential capacity to synthesize various proinflammatory mediators, and inhibition of their production is expected to result in anti-inflammatory effects. In this study, we investigate the effects of the anti-inflammatory cytokines, interleukin-10 (IL-10) and IL-4, on prostanoid synthesis in human neutrophils. Neutrophils isolated from healthy donors constitutively produced a small amount of prostaglandin E2 (PGE2) without any stimulations, whereas they produced a large amount of PGE2 after lipopolysaccharide (LPS) stimulation. IL-10 and IL-4 selectively inhibited their LPS-induced PGE2 production. Inhibition by both cytokines occurred at an early stage of LPS stimulation. Anti-IL-10 treatment of LPS-stimulated neutrophils resulted in enhanced PGE2 production. LPS-induced PGE2 and thromboxane B2 (TXB2) production in aspirin-treated neutrophils was significantly inhibited by IL-10, IL-4, and NS-398. Moreover, IL-10 and IL-4 inhibited LPS-induced cyclooxygenase (COX) activity in neutrophils. Western blot and immunocytochemical analysis showed that COX-2 protein was clearly induced in LPS-stimulated neutrophils and that its induction was inhibited by both IL-10 and IL-4. Moreover, both of these cytokines inhibited COX-2 mRNA expression in LPS-stimulated neutrophils. These results raise the possibility that these two cytokines may both offer potent clinical utility as anti-inflammatory agents in the future.

Polysaccharide from Aspalathus linearis with strong anti-HIV activity

Polysaccharide that has been extracted with 1% sodium carbonate from Rooibos leaves (Aspalathus linearis) showed strong anti-HIV activity. Du-Zhong leaves also showed anti-HIV activity, although lower than the extract of Aspalathus linearis, but Japanese tea leaves and a hot water extract of Aspalathus linearis did not. The anti-HIV activity of the alkaline extract from Aspalathus linearis was recovered mainly in the 25-75% ethanol-precipitated fraction. The polysaccharide almost completely inhibited the binding of HIV-1 to MT-4 cells. It is inferred from these results that the polysaccharide from Aspalathus linearis is involved in the mechanism for virus binding to T cells.

Application of alginate gel as a vehicle for liposomes. II. Erosion of alginate gel beads and the release of loaded liposomes

The possibility of producing calcium-induced alginate gel beads as a vehicle for liposomes was explored. The maximal loading of egg phosphatidylcholine liposomes (ca. 26 nm in diameter) in a fully-cured bead (1.2 mm in radius, initial alginate concn. of 4%) was 2.9 x 10(-6) mol/bead or ca. 18%, and the size of the bead slightly increased with an increase in liposome loading. The liposomes were well maintained within both fully-cured and washed beads. The liposome release from the fully-cured bead was much slower than that from the corresponding washed bead in a pH 7.4 releasing medium. The greater the liposome loading, the faster the release of the vesicles. The liposome release was investigated in terms of liposome loading, swelling of the gel body, calcium discharge and gel erosion, using washed beads. The liposome loading did not affect the bead erosion or calcium discharge but did the initial swelling ratio and liposome release. The results suggest that the loaded liposomes are not uniformly distributed in the bead but are rather gradually concentrated to the center. Such an inhomogeneous distribution of liposomes is possibly due to the fact that the gelation occurred instantly on the surface of the droplets, and the resulting gel network or layer acts as semipermeable membrane for liposomes and forces the vesicles to move into deeper concentric sections as gelation proceeds to the interior. As the liposomes loading increases, the forced migration might be very limited because of concentrically decreasing extra room to accommodate the vesicles in the bead.

Chloropeptins, new anti-HIV antibiotics inhibiting gp120-CD4 binding from Streptomyces sp. I. Taxonomy, fermentation, isolation, and physico-chemical properties and biological activities

Chloropeptins I and II, which are gp120-CD4 binding inhibitors, were isolated as pale yellow-brown powders from the mycelia of a soil actinomycete, Streptomyces sp, WK-3419. Their physico-chemical properties showed that they are chlorinated peptides. Chloropeptin I (C61H45N7O15Cl6) is a novel compound, but chloropeptin II was identified as complestatin. Both compounds inhibited gp120-CD4 binding (IC50: 1.3 and 2.0 microM, respectively), the cytopathic effect of HIV in MT-4 cells (EC50: 1.6 and 1.7 microM, respectively) and syncytium formation in co-cultured HIV-1-infected and uninfected MOLT-4 cells (IC50. 0.5 and 1.1 microM, respectively). Chloropeptin I was synergistic in the inhibition of the cytopathic effect when combined with other anti-HIV drugs such as zidovudine (AZT), didanosine (ddI), zalcitabine (ddC) and nevirapine.

The feasibility of epidural anesthesia without endotracheal intubation for abdominal surgery in patients with collagen diseases

BACKGROUND/AIMS

Patients with collagen diseases are generally regarded as high-risk surgical candidates.

MATERIAL AND METHODS

To evaluate the feasibility of epidural anesthesia and to determine the risk factors in abdominal surgery for patients with collagen diseases, 20 patients with collagen diseases who underwent elective abdominal surgery were examined for their surgical outcomes and clinical characteristics. Among the 20 cases, 12 received epidural anesthesia alone without endotracheal intubation, 3 received general anesthesia only, 4 received general anesthesia with epidural anesthesia and one received lumbar anesthesia.

RESULTS

Only one patient receiving epidural anesthesia died after operation. The mortality in patients receiving epidural anesthesia was 8.3% (1/12) while the overall mortality was 5.0% (1/20). No significant difference was observed either in the mortality or incidence of postoperative complications among the 4 groups according to the method of anesthesia. Patients with a dysfunction of the vital organs more often had postoperative complications than those without a dysfunction of the vital organs (p = 0.043).

CONCLUSIONS

Although only a small number of patients were included in this study, these results suggested that 1) elective abdominal surgery can be as safely performed under epidural anesthesia alone as with general anesthesia even for patients with collagen diseases, and 2) the patients with collagen diseases, who preoperatively showed a dysfunction of the vital organs, might be at a higher risk for abdominal surgery.

Successful foscarnet therapy for mucocutaneous infection with herpes simplex virus in a recipient after unrelated bone marrow transplantation

A 36-year-old Japanese man who received an unrelated bone marrow transplant (BMT) developed severe mucocutaneous infection with herpes simplex virus (HSV) type 1 during oral acyclovir prophylaxis. The lesions progressed despite treatment with intravenous acyclovir and vidarabine. The HSV isolates were sensitive acyclovir, vidarabine and foscarnet in vitro, but peripheral CD3- or CD19-positive cells were barely detectable even 4 months after transplant. A 12-day course of treatment with foscarnet led to a rapid improvement. Foscarnet therapy should be considered for all severe HSV infections following BMT, regardless of whether or not the HSV isolates are sensitive to acyclovir.

Relaxation of insulin-like growth factor 2 gene imprinting in esophageal cancer

Paternal allele-specific expression is identified for the insulin-like growth factor 2 (IGF2) gene. Relaxation or loss of IGF2 imprinting, however, has been reported in several neoplasms. We studied the expression of IGF2 mRNA in 35 squamous cancers of the esophagus and searched for the presence or absence of relaxation of IGF2 imprinting. In 28 (80%) cases, IGF2 mRNA was overexpressed in the tumor tissues (T) compared to the normal tissues (N). The patients whose tumor invaded the adventitia showed a higher T/N ratio than those whose tumor was restricted to the musculi propria layer. Heterozygosity was determined by using the Apa I polymorphism in exon 9. Thirteen of 35 cases showed heterozygosity. In these 13 cases, a similar analysis was performed on cDNA obtained by reverse transcriptase-polymerase chain reaction. Consequently, 7 cases disclosed relaxation of IGF2 imprinting in the tumor tissue. The cases of esophageal cancer with relaxation of IGF2 imprinting showed a higher T/N ratio and deeper invasion than those without relaxation. The results suggest that overexpression of IGF2 mRNA plays an important role in esophageal cancer and, in certain cases, is associated with relaxation of IGF2 imprinting.

Hairpin antisense oligonucleotides containing 2'-methoxynucleosides with base-pairing in the stem region at the 3'-end: penetration, localization, and Anti-HIV activity

Hairpin antisense oligodeoxyribonucleotides containing 2'-methoxynucleosides were more active in the micromolar concentration range than linear and DNA hairpin phosphorothioate oligonucleotides with the same sequence. Furthermore, the abilities of hairpin antisense and random hairpin phosphorothioate oligonucleotides to inhibit HIV-1 replication were examined. Antisense oligonucleotides inhibit the replication and the expression of HIV-1 more efficiently than random-oligomers of the same length or with the same internucleotide modification. Four different target sites (gag, pol, rev, and tat) within the HIV-1 genome were studied with regard to the inhibition of HIV-1 replication by antisense oligonucleotides. Antisense oligomers complementary to the sites of the initiation sequences of gag were most effective. The [32P]-labeled hairpin phosphorothioate oligonucleotide was rapidly assimilated by MOLT-4 cells, whereas the [32P]-labeled hairpin phosphodiester oligonucleotide was not. In MOLT-4 cells treated with the FITC-hairpin phosphorothioate oligonucleotide containing 2'-methoxynucleosides by a confocal laser scanning microscope, diffuse fluorescence was observed in the cytoplasm. Interestingly, fluorescent signals accumulated in the nuclear region of chronically infected MOLT-4/HIV-1 cells after a 60 min incubation.

Surgical management of patients with radiation enteritis

To improve the surgical outcome in patients with radiation enteritis, 18 female cases were analyzed. Out of the 18 cases, 3 (16.7%) were treated conservatively while 15 (83.3%) underwent surgical procedures. Thirteen out of 14 patients (92.8%) with ileus underwent an operation. The overall mortality was 22.2% (4 out of 18 cases). However, no significant difference in the mortality between the operated and non-operated cases was observed. Although an analysis of the 15 operated cases did not reveal any significant factors that might have affected the prognosis, all four patients who underwent a bypass operation showed a good postoperative course, with only one excepting being a patient suffering from malnutrition. Although only a small number of patients were included in this study, these results suggest that 1) surgeons should not hesitate to operate on patients with radiation enteritis demonstrating ileus, and 2) a bypass operation may be one surgical alternative in the presence of massive adhesion or for patients at high risk for a standard operation.

Light-induced phase shifting of the circadian conidiation rhythm is inhibited by calmodulin antagonists in Neurospora crassa

The effects of calmodulin antagonists and inhibitors of protein kinases and phosphatases on light-induced phase shifting were investigated in Neurospora crassa. Calmodulin antagonists, namely, trifluoperazine, chlorpromazine, and W-7, almost completely inhibited the light-induced phase shifting without having any effect on the circadian clock itself. Chlorpromazine was less effective in inhibiting the light-induced phase shifting than trifluoperazine. W-5, a dechlorinated analogue of W-7, failed to inhibit the light-induced phase shifting at the same concentration as that at which W-7 was effective. These results suggest that calmodulin is required during signal transduction from the light-perceiving system to the circadian clock in N. crassa. Inhibitors of protein phosphorylation did not inhibit the light-induced phase shifting, although these inhibitors completely inhibited mycelial growth. Trifluoperazine partially inhibited the phosphorylation of three proteins when phosphorylation was assayed in vitro.

[Evaluation of regional cerebral blood flow in hippocampus by 99mTc-ECD SPECT: comparison with 123I-IMP SPECT]

We evaluated regional cerebral blood flow in the hippocampus in 21 patients with neurological disorders by 99mTc-ethyl cysteinate dimer (ECD) SPECT and compared the findings with those by 123I-N-isopropyl-p-iodoamphetamine (IMP) SPECT. In all subjects, SPECT was taken using ECD (740 MBq) and IMP (167 MBq) using high performance SPECT (3-head SPECT, Toshiba GCA-9300A/HG) within 3 weeks interval. Regional uptake in the hippocampus was examined in the coronal sections and images parallel to the longitudinal axis of hippocampus. ECD and IMP showed similar hippocampal uptake in 9 cases, but ECD showed less uptake than IMP in 12 cases (57%). Regional counts in the hippocampus were related to the counts in the lateral temporal cortices and the mean count ratio was lower in ECD by 8.8% than that in IMP (0.73 +/- 0.11 vs. 0.80 +/- 0.11, p < 0.001). In 6 patients suspected to have hippocampal lesion (4 cases of memory disturbance and 2 cases of epilepsy), all cases showed decreased uptake of ECD in hippocampus, but only 3 cases showed decreased uptake of IMP. This is suggestive to be relevant to the difference in the retention mechanism of ECD and IMP, but further investigation should be performed.

Direct activation of the ATP-sensitive potassium channel by oxygen free radicals in guinea-pig ventricular cells: its potentiation by MgADP

The effects of hydrogen peroxide (H2O2) on the activity of adenosine 5'-triphosphate-sensitive potassium (K+ ATP) channels in ventricular cells isolated from guinea-pig hearts were investigated in inside-out membrane patches using the patch-clamp technique. H2O2 at concentrations of 5 mM but not 1 mM increased K+ ATP channel activity in the presence of 0.3 mM ATP. The presence of 10 microM ADP together with 0.3 mM ATP led to activation of the K+ ATP channel by 1 mM H2O2. This potentiation of the H2O2-induced activation of the K+ ATP channel by ADP depended on the presence of Mg-ATP. Channel activation was due to an increase in the open-state probability and was not associated with a change in the single-channel conductance or the mean open and closed times during burst-like openings. The relationship between channel activity and ATP concentration could be fitted by the Hill equation with a Hill coefficient of 2 and the half maximal inhibition at 85 microM ATP in the presence of 10 microM ADP. The curve was shifted to higher ATP concentrations in a non-parallel manner by 1 mM H2O2. Analysis of open-state probability for membrane patches containing several channels indicated that H2O2 activated the individual channels to a differing extent. It is concluded that H2O2 activates the K+ ATP channel directly by decreasing the sensitivity to ATP. This effect was potentiated by the presence of ADP.

Expression of MAGE genes in human colorectal carcinoma

OBJECTIVE

The human genes MAGE-1 and -3 encode tumor-specific peptide antigens, which are recognized by autologous cytotoxic T lymphocytes. The antigens coded by those genes may be useful for cancer immunotherapy. There is, however, little information on the expression of these genes in human colorectal carcinomas.

METHOD

The expression of MAGE-1, -2, and -3 genes in 54 pairs of tumor and corresponding normal tissue specimens of the colorectum was determined by means of reverse transcription polymerase chain reaction. The induction of MAGE-1, -2, -3, and -4 gene expression in eight colorectal carcinoma cell lines also was examined by use of a demethylating agent, 5-Aza-2'-deoxycytidine (DAC).

RESULTS

The expression of MAGE genes was not recognized in normal colorectal tissues at all. In tumor tissue specimens, the expression of MAGE-1, -2, and -3 was recognized in 16 (30%), 15 (28%), and 11 (20%) patients, respectively. The expression was seen frequently in patients with liver metastasis (p < 0.01). Although MAGE-1 or -3 genes were not induced by DAC, MAGE-2 or -4 genes were induced in three of four MAGE-2 negative cell lines or three of seven MAGE-4 negative cell lines, respectively.

CONCLUSIONS

The MAGE genes were expressed exclusively in tumor tissues of one third of patients with colorectal carcinoma. The identification of such tumor rejection antigens is considered to uncover a new possibility for the specific immunotherapy of colorectal carcinoma. The demethylating agent may increase the number of patients who might be candidates for MAGE-specific immunotherapy.

Erythrocyte deformability in schizophrenic patients

Erythrocyte deformability as a clinical indicator of microcirculatory disturbance was determined in the erythrocyte of 25 schizophrenic patients and of 18 normal controls. Schizophrenic patients had significantly lower erythrocyte deformability than did the normal controls (P < 0.001). This result suggests that microcirculation in schizophrenic patients is disturbed, and that this disturbance might be involved in the pathophysiological genesis of schizophrenia.