Stereospecificity of 6'-C-neplanocin A analogues as inhibitors of S-adenosylhomocysteine hydrolase activity and human immunodeficiency virus replication

The R- and S-isomers of 6'-C-neplanocin A analogues, which are all known as inhibitors of S-adenosylhomocysteine (AdoHcy) hydrolase, were studied for their inhibitory effects on Human Immunodeficiency Virus type 1 (HIV-1) replication and HIV-1 Tat-mediated transactivation. The R-isomers showed much greater activity against AdoHcy hydrolase than the S-isomers. The same differential activity was observed against the HIV-1 replication and the Tat transactivation.

[Effects of folic acid supplementation on hyperhomocysteinemia in CAPD patients: effects on unsaturated fatty acids]

Hyperhomocysteinemia has been recognized as one of the risk factors for atherosclerosis and premature vascular disease. Patients on dialysis and end-stage renal disease also manifest high plasma concentrations of homocysteine. We performed this study to evaluate the effects of folic acid supplementation on hyperhomocysteinemia in CAPD patients. Twenty-three CAPD patients (8 males, 15 females, 49.1 +/- 14.2-years-old) dialyzed for 22.7 +/- 19.2 months participated in the study. Daily 5-mg doses of folic acid supplementation for 4 weeks significantly reduced plasma concentrations of total homocysteine (p < 0.01) and serine (p < 0.001). This observation suggests that the reduction of plasma concentrations of total homocysteine results from activation of homocysteine remethylation to methionine. On the other hand, folic acid supplementation also revealed significant correlations between changes in serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid and changes in plasma concentrations of total homocysteine (r = -0.517, p < 0.05, r = -0.451, p < 0.05, respectively). In addition, serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid in 11 CAPD patients with hyperhomocysteinemia (> or = 35 micromol/litter) were significantly lower than those of 12 CAPD patients with normohomocysteinemia (< 35 micromol/litter) (p < 0.05, p < 0.05, respectively). Serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid in CAPD patients with hyperhomocysteinemia increased significantly (p < 0.01, p < 0.05, respectively) and reached similar levels of CAPD patients with normohomocysteinemia, while plasma concentrations of total homocysteine decreased after folic acid supplementation. These findings suggest that correction of hyperhomocysteinemia in patients on dialysis produces an increase in unsaturated fatty acids.

Nucleosides and nucleotides. 170. Synthesis and properties of oligodeoxynucleotides containing 5-[N-[2-[N,N-bis(2-aminoethyl)- amino]ethyl]carbamoyl]-2'-deoxyuridine and 5-[N-[3-[N,N-bis(3-aminopropyl) amino]propyl]carbamoyl]-2'-deoxyuridine

The synthesis of oligodeoxynucleotides (ODNs) containing 5-[N-[2-[N,N-bis(2-aminoethyl)amino]ethyl]-carbamoyl]-2'-deoxyuridine (BAE) and 5-[N-[3-[N,N-bis(3-aminopropyl)amino]propyl]carbamoyl]-2'- deoxyuridine (BAP) is described. The thermal stabilities of duplexes containing these ODNs and either the complementary DNA or RNA strand and of triplexes consisting of these ODNs and the target duplex were studied by thermal denaturation. ODNs containing BAE or BAP stabilize duplex formation with either the complementary DNA or RNA strands but destabilize triplex formation with the target duplex. Furthermore, the resistance of these ODNs to nuclease hydrolysis was studied by using snake venom phosphodiesterase (a 3'-exonuclease) and nuclease S1 (an endonuclease). It was found that ODNs containing either BAE or BAP were more resistant to nucleolytic hydrolysis by either of the nucleases than the unmodified ODN.

[Effects of various Ringer's solutions on acid-base balance in rats in hemorrhagic shock and with hepatic dysfunction]

We investigated the effects of bicarbonated Ringer's solution (BR) on arterial blood acid-base balance, and compared these with the effects of lactated Ringer's solution (LR) and acetated Ringer's solution (AR) in rats in hemorrhagic shock. Rats underwent 70% reduction of hepatic blood flow and blood shedding of 1.5% of body weight. Each solution was infused through the femoral vein at a rate of shed blood volume x 8.hr-1 for 30 min under urethane anaesthesia. After the blood shedding, arterial blood pH and HCO3-decreased but plasma lactate concentration increased. These parameters improved significantly in the BR group compared with those in the LR group. However, the LR group showed the lowest blood pH and the highest plasma lactate concentration among the groups. These results suggest that BR has superior effects on the arterial blood acid-base balance and glucose metabolism in rats in hemorrhagic shock and with hepatic dysfunction.

[Characteristics of home parenteral nutrition and effectiveness of 3 way valved PICC in regional medical care]

Home medical care is becoming a greater matter of concern along with the increasing population of elderly persons. The various difficulties in home care are also found in regional care, and it could be said that in Japan regional care serves as an "advanced model" for home medical care. Ohya Town is located in the mountains of northern Hyogo Prefecture. It has a population of about 5,000 of which 32% is elderly people. There is no railroad, and it takes around 30 minutes to travel to the central hospital from the area. The three town clinics are in contact with each other and with the central hospital concerning medical information. The characteristics of Home Parenteral Nutrition in this underpopulated district are discussed and reported in reference mainly to cases in which the 3 way valved peripherally inserted central venous catheter (Groshong Catheter) is used, in comparison with HPN cases in the city university hospital.

[Effects of establishing a special smoking area in the office of an electronic factory]

Measurements of concentrations of suspended particles and a questionnaire survey at the office of an electronic factory were conducted before and after the establishing of a special smoking area. Compared with the previous conditions where smoking had been allowed during a specified time, the suspended particle concentration has decreased to less than one fifth of the previous condition. Both smokers and non-smokers are satisfied with the establishment of the smoking area. All were convinced that the separation of the smoking permissible area and non-smoking area was more effective than the time restriction on smoking.

Magnetic resonance imaging patterns in patients with multiple myeloma

Sixty-one consecutive patients with multiple myeloma were studied with magnetic resonance (MR) imaging of the spine. Sagittal T1-weighted and short inversion time (TI) inversion recovery (STIR) images were obtained. The MR patterns of the bone marrow were classified as diffuse (D) (n=26), nodular (N) (n=11), D+N (n=13) or normal (n) (n=11). Abnormal patterns were seen in 50 (82%) of the 61 patients. Correlations were found between the MR imaging patterns and some laboratory findings (WBC, haematocrit, platelet count, serum albumin, and percentage of marrow plasmacytosis). The survival of the patients with abnormal MRI patterns was significantly poorer than that of the patients with normal patterns. However, the survival of patients with a nodular pattern did not differ from those with a normal pattern. The MR imaging pattern of the bone marrow in patients with multiple myeloma is a useful factor in the assessment of prognosis.

A homozygous missense mutation of the sodium/iodide symporter gene causing iodide transport defect

Iodide transport defect is a disorder characterized by an inability of the thyroid to maintain an iodide concentration difference between the plasma and the thyroid. The recent cloning of the sodium/iodide symporter (NIS) gene enabled us to characterize the NIS gene in this disorder. We identified a homozygous missense mutation of A-->C at nucleotide +1060 in NIS complementary DNA in a male patient who was born from consanguineous marriage, had a huge goiter, and lacked the ability to accumulate iodide but was essentially euthyroid. The mutation results in an amino acid replacement of Thr354-->Pro in the middle of the ninth transmembrane domain. COS-7 cells transfected with the mutant NIS complementary DNA showed markedly decreased iodide uptake, confirming that this mutation was the direct cause of the disorder in the patient. Northern analysis of thyroid ribonucleic acid revealed that NIS messenger ribonucleic acid level was markedly increased (> 100-fold) compared with that in the normal thyroid, suggesting possible compensation by overexpression.

Correlation between intravenously supplied energy level and zinc metabolism in laparotomized rats

We investigated the relationship between intravenous energy loading and zinc status in laparotomized rats. One of three test solutions consisting of 3% amino acid, the same amount of electrolytes (excluding zinc) and different concentrations of glucose were infused through the jugular vein for 5 d. The total energy was 109, 191 and 273 kcal/kg/d, respectively. Significantly positive correlations were observed between infusion energy and rat body weight changes (% of initial value) and between infusion energy and cumulative nitrogen balance. Regarding the zinc status, a negative correlation was found between infusion energy and plasma zinc concentration, and a positive correlation was observed between infusion energy and urinary zinc excretion. There was no significant relationship between infusion energy and hepatic zinc content. These results indicate that the zinc requirement might be increased when infusion energy is elevated and the nutritional status is improved. Zinc supplementation in the post-operative period should be considered in light of not only catabolism but also anabolism. Anabolism may be more important than catabolism in regard to zinc metabolism under relatively mild stress.

Neplanocin A, a potent inhibitor of S-adenosylhomocysteine hydrolase, potentiates granulocytic differentiation of acute promyelocytic leukemia cells induced by all-trans retinoic acid

Several neplanocin A analogs were synthesized and their growth-inhibiting and differentiation-inducing activities on myelogenous leukemia cells were examined. An adenosine kinase-ineffective analog of neplanocin A was effective in inducing differentiation, suggesting that phosphorylation of the nucleoside is not essential for inducing the differentiation of leukemia cells. Neplanocin A induced functional and morphological differentiation of HL-60 cells, but did not effectively induce differentiation of NB4, a cell line derived from a leukemia patient with t(15;17). However, these cells have been known to undergo granulocytic differentiation upon treatment with all-trans retinoic acid (ATRA), and are used as a model for differentiation therapy in acute promyelocytic leukemia. Preexposure of NB4 cells to low concentrations of neplanocin A greatly enhanced the ATRA-induced differentiation of the cells, whereas representative antileukemic drugs such as cytosine arabinoside and daunomycin did not enhance this differentiation. A clinical strategy that combines intermittent treatment with neplanocin A analogs and a low dose of ATRA may increase the clinical response and decrease the adverse effects of ATRA.

Differential expression of maf-1 and maf-2 genes in the developing rat lens

PURPOSE

To examine the expression of maf-1 and maf-2 protocogenes in the developing rat lens.

METHODS

Maf-1 and maf-2 transcripts were assayed in rat lenses on embryonic days 13 and 16 (E13 and E16) by in situ hybridization using single-stranded RNA probes. Proteins encoded by the maf-2 gene were assayed immunocytochemically in embryonic (E12, 13, 16, 19) and postnatal day 14 and 90 (P14 and P90) lenses.

RESULTS

In embryonic lenses, we detected maf-1 messenger RNA (mRNA) in the lens epithelium and maf-2 mRNA diffusely distributed in the lens fiber cells. By immunocytochemistry, Maf-2 was detected on E12 in the nuclei of almost all lens pit cells. On days E13, E16, and E19, however, lens epithelial cells showed no immunoreactivity, but nuclei of fiber cells reacted strongly. On P14, nuclei containing Maf-2 protein were confined to the equator of the lens, but at 3 months of age, no Maf-2 could be detected in the rat lens. Western blotting showed that the anti-Maf-2 antiserum reacted with a single protein, of molecular weight approximately 39 kDa, in rat lens.

CONCLUSIONS

Results showed the spatial and temporal regulation of maf gene expression and suggest that these genes participate in transcriptional regulation during the development of the lens in the rat.

Inhibition by aminosalicylates of lipid peroxidation in large intestinal mucosa after mesenteric ischemia/reperfusion in the rat

To clarify the mode of action of aminosalicylates, which are generally used as therapeutic agents for ulcerative colitis, we investigated the effect of some of the aminosalicylates on lipid peroxidation in the large intestinal mucosa after mesenteric ischemia/reperfusion in the rat. Lipid peroxidation was assessed by measuring the level of thiobarbituric-acid-reactive substances. It was found that aminosalicylates dose-dependently inhibited the elevation of the level of thiobarbituric-acid-reactive substances in the large intestinal mucosa after ischemia/reperfusion. This effect may partly contribute to the therapeutic actions of aminosalicylates in ulcerative colitis.

Selenium level and glutathione peroxidase activity in plasma, erythrocytes and platelets of healthy Japanese volunteers

The purpose of this study was to determine both the selenium (Se) level and glutathione peroxidase (GSH-Px) activity in plasma, erythrocytes and platelets from 51 healthy Japanese individuals. The Se levels (mean +/- SD) of plasma, erythrocytes and platelets were 117.4 +/- 15.7 micrograms/L, 0.954 +/- 0.159 microgram/g hemoglobin, and 4.93 +/- 1.52 ng/mg protein, respectively, and GSH-Px activity was 318 +/- 50 U/L, 18.0 +/- 5.0 U/g hemoglobin, and 0.142 +/- 0.035 U/mg protein, respectively. There was a negative correlation between age and the platelet Se level in men (r = -0.761, p < 0.001), and a positive correlation between the plasma and platelet GSH-Px activities in women (r = 0.663, p < 0.001).

Effects of 5-(N-aminohexyl)carbamoyl-2'-deoxyuridine on endonuclease stability and the ability of oligodeoxynucleotide to activate RNase H

To evaluate an endonuclease resistance property of oligodeoxynucleotides (ODNs) containing 5-(N-aminohexyl)carbamoyl-2'-deoxyuridines (Hs) and to elucidate whether a duplex consisting of the ODN analogue and its complementary RNA induces RNase H activity, the ODNs containing the deoxyuridine analogues, Hs, at intervals of one, two, three, four and five natural nucleosides were synthesized. From partial hydrolysis of these ODNs with nuclease S1 (an endonuclease), it was found that the ODNs became more stable towards nucleolytic hydrolysis by the enzyme as the number of H increased. Furthermore, to examine whether the duplexes composed of the ODNs containing Hs and their complementary RNAs are substrates for RNase H or not, the duplexes of these ODNs and their complementary RNA strands were treated with Escherichia coliRNase H. It was found that cleavage of the RNA strands by the enzyme was kinetically affected by the introduction of Hs into the duplexes.

Bone marrow patterns in patients with aplastic anaemia and myelodysplastic syndrome: observations with magnetic resonance imaging

Bone marrow magnetic resonance imaging (MRI) was obtained in 48 patients with myelodysplastic syndrome (MDS) (35 cases) or aplastic anaemia (AA) (13 cases). The lower thoracic and lumbar spine were evaluated on sagittal plane using a 1.5 Tesla superconducting MR unit with a surface coil. Pulse sequence of STIRs (TR 2000 msec, TI 160 msec, TE 20 msec) were applied. Four distinct patterns of signal intensity (SI) on the STIR images were classified as follows: pattern 1, homogeneously low SI; 2, marginally high SI; 3, heterogeneously high SI; 4, homogeneously high SI. In all 13 patients with AA, STIR images initially revealed pattern 1. In 25 of 35 cases with MDS patients, the STIR images were initially classified as pattern 3. The STIR images of 6 AA and 5 MDS patients with a clinical response to treatment showed pattern 2 similar to that of normal marrow distribution. The STIR images of MDS patients showed an abnormal distribution of SI. Significant signal changes in the STIR images can be observed in successive examinations of the patients, thus facilitating follow-up of the disease and treatment. MRI of the bone marrow provides a noninvasive means of grossly examining a large fraction and is a useful technique in patients with aplastic anaemia or myelodysplastic syndrome.

[Nucleoside kinases and new types of antitumor nucleosides]

The nucleoside kinases phosphorylate nucleosides to corresponding nucleoside 5'-monophosphates. Their activities are essential for activation of chemotherapeutically important nucleoside analogues. Since, among them, deoxycytidine kinase has high activity in a wide variety of tumor tissues, a relatively low substrate specificity, and is not cell-cycle regulated, 2'-substituted-2'-deoxycytidine analogues should be suitable for antitumor antimetabolites. Gemcitabine, DMDC, and CNDAC have been developed for such analogues. These nucleosides showed potent antitumor activity against various solid tumors. They inhibited mainly DNA synthesis of tumor cells and, to some extent, inhibited RNA synthesis. To inhibit RNA synthesis of tumor cells would be important to kill solid tumor cells, which are heterogenous. ECyd was designed as an inhibitor of both DNA and RNA syntheses and showed potent antitumor activity against a variety of human tumor cells in xenografts.

Hydrolytic profile for ester- or amide-linkage by carboxylesterases pI 5.3 and 4.5 from human liver

Carboxylesterases (EC 3.1.1.1) from human liver were purified using Q-Sepharose, Sephadex G-150, isoelectrofocusing and Con A-Sepharose. The calculated molecular mass of the pI 5.3 enzyme was 120 kDa and 61 kDa from the results of Sephadex G-150 gel filtration and SDS-polyacrylamide gel electrophoresis (PAGE), respectively, suggesting that this enzyme is a dimer. On the other hand, carboxylesterase pI 4.5, with a molecular mass of 64 kDa, was a monomer. The activities of both enzymes were inhibited by typical serine enzyme inhibitors. Amino acid sequence analysis of the purified enzymes pI 5.3 and 4.5 showed high homology with rabbit carboxylesterase form 1 and 2, respectively. The results also suggested that carboxylesterase pI 5.3 is identical to the deduced amino acid sequence from cDNA for HU1, and that carboxylesterase pI 4.5 is identical to the deduced amino acid sequence from the cDNA registered as human carboxylesterase (hCE-2) in GenBank. We first purified carboxylesterase pI 4.5 and investigated its hydrolytic activity upon various drugs. The two enzymes differed in substrate specificity. Prodrugs of angiotensin-converting enzyme inhibitors, such as delapril and imidapril, were converted to active metabolites by carboxylesterase pI 5.3, but not by carboxylesterase pI 4.5. The hydrolysis velocity of temocapril by carboxylesterase pI 5.3 was 12-fold faster than by carboxylesterase pI 4.5. In contrast, aspirin, oxybutynin and procaine were hydrolyzed by only carboxylesterase pI 4.5. We also found that an amide-linkage in drugs, except for that in aniracetam, was not a good substrate for the two enzymes. Consequently, carboxylesterases pI 5.3 and 4.5 may be involved in the metabolism of various drugs containing an ester-linkage.

Recent trends in the management of Graves' hyperthyroidism in Japan: opinion survey results, especially on the combination therapy of antithyroid drug and thyroid hormone

An opinion survey concerning the management of Graves' hyperthyroidism was conducted among the council members of the Japan Thyroid Association. The selection of 3 major treatments by 90 respondents for their patients was 98.6 +/- 4.2% for antithyroid drug (ATD), 7.8 +/- 12.6% for partial thyroidectomy and 5.2 +/- 8.1% for radioiodide. They expressed a movement away from the past trend of surgery because of postoperative complications and unsatisfactory therapeutic results, and they assumed a further reduction in the future. On the other hand, the frequency of radioiodide treatment was not considered to have decreased greatly, and they expected a slight increase in the future. Of the respondents, 65% suggested that hyperthyroidism should be completely cured even if the patient would fall into hypothyroidism. The major reasons for choosing surgery or radioiodide after ATD were the adverse effects of ATD and the age and social backgrounds of the patients. Large goiter size was the 3rd reason for surgery but was a minimal indicator for radioiodide. As for ATD treatment, none of the respondents reported the routine application of any uniform fixed-time therapy protocol. Japanese Graves' patients were shown to be less responsive to ATD than Caucasian patients. This was assumed to result at least from high iodide intake, and half of them had ordered their patients to restrict iodide intake. Furthermore, 78% of them had treated with a combined therapy of ATD and thyroid hormone. Most of them apply this for selected patients mainly to lower TSH receptor antibody activity, to better control their patients and to reduce the goiter size. All but 8 (9%) did not give T4 (or T3) after the cessation of ATD, and they felt this to be unnecessary, doubtful about the effect, unsuitable or even possible to induce recurrence. The excellent findings reported by Hashizume et al. (N Engl J Med 324: 947-953, 1991) are well known among them. However, most of them did not agree with the efficacy of the protocol to reduce TRAb or to improve the remission rate, and 90% of the respondents did not intend to apply the protocol immediately. In conclusion, the Japanese thyroidologists were shown to highly prefer ATD, and they intended to treat their patients for longer periods of time only by ATD until clinical remission is achieved. The combination therapy is widely used, but most of them do not consider it effective. The therapeutic protocol reported by Hashizume et al. was not accepted widely in Japan.

Treatment of hyperthyroidism with a small single daily dose of methimazole: a prospective long-term follow-up study

A prospective long-term follow-up study was performed with conventional divided doses (group C: 10 mg 3 times daily, N = 58) and a small single daily dose (group S: 15 mg once daily, N = 54) of methimazole (MMI) for the treatment of Graves' hyperthyroidism. Within 8 weeks, almost 80% of the patients in both groups became euthyroid. The mean time required to achieve a euthyroid state was 5.6 +/- 2.7 weeks in group C and 5.8 +/- 3.1 in group S. TSH binding inhibitor immunoglobulin (TBII) levels before therapy were 44.2 +/- 22.7% and 47.1 +/- 23.9% in group C and group S, respectively. A similar gradual fall in TBII levels was observed in both groups over a two-year period of treatment. MMI doses were gradually reduced to a maintenance dose (5 mg daily) after the patients became euthyroid. The patients were treated for 28 +/- 9 months and were followed up after therapy was stopped (observation period in patients who remained in remission was 12-130 (75 +/- 34) months and the interval to relapse in recurred cases was 1-98 (20 +/- 27) months). The rates of recurrence in group C were 41% at 1 yr, 54% at 2 yrs, 56% at 4 yrs and 61% at 6 yrs. In group S, these were 44%, 53%, 56% and 63%, respectively. No differences between relapse rates were observed with the two different dosage regimens. Adverse effects occurred more frequently in group C patients (24%) than in group S patients (13%). These results show that there is no difference in the clinical and immunological course or in the long-term remission rate of Graves' hyperthyroidism when the treatment is initiated with either a small single daily dose (15 mg) or the conventional regimen (10 mg 3 times daily).

Site-specific introduction of functional groups into phosphodiester oligodeoxynucleotides and their thermal stability and nuclease-resistance properties

We report here the site-specific introduction of functional groups into phosphodiester oligodeoxynucleotides (ODNs). ODNs containing both 5-( N-aminohexyl)-carbamoyl-2'-deoxyuridine (H), which serves as a tether for the further conjugation of functional groups, and 5-(N,N-dimethylaminohexyl)carbamoyl-2'-deoxyuridine (D), which contributes to the thermal stability of the duplex and to the resistance to nucleolytic hydrolysis by nucleases, were synthesized. Functional groups such as folic acid and palmitic acid were site-specifically introduced into the terminus of the aminohexyl-linker of H. The thermal stability and resistance toward nuclease digestion of the modified ODNs were studied. We found that ODNs containing D and H formed stable duplexes with both the complementary DNA and RNA strands even when a bulky functional group such as folic acid, palmitic acid or cholesterol was attached to the terminus of the amino-linker. We also found that ODN analogues which contained D were more resistant to nucleolytic degradation by exo- and endonuclease than the unmodified ODN. Furthermore, duplexes formed by ODNs containing D and the complementary RNA could elicit RNase H activity.