Characterization and chromosomal mapping of a human Necdin pseudogene

The necdin gene is expressed predominantly in postmitotic neurons and encodes a growth suppressor that interacts with the transcription factors E2F1 and p53. Human necdin gene (NDN) is maternally imprinted and located in Prader-Willi syndrome deletion region 15q11.2-q12. We isolated an NDN homologous sequence from a human genomic DNA library. The homologous sequence is overall 83% identical with necdin cDNA sequence, and possesses a short poly(A) stretch at the 3' end and direct repeats at both ends. Expression of the homologous sequence, which lacks a 5' promoter sequence, was undetected in cultured human cell lines. We mapped this sequence to chromosome 12q14-q21.1 by fluorescence in situ hybridization. These characteristics of the NDN-homologous sequence are consistent with those of processed pseudogenes. The information about the necdin pseudogene in the human genome will be useful for genetic studies on NDN-associated neurogenic disorders.

Ameliorative effects of tamolarizine on place learning impairment induced by transient forebrain ischemia in rats

In the present study we investigated the effect of (+/-)-1-(3, 4-dimethoxyphenyl)-2-(4-diphenylmethylpiperazinyl) ethanol dihydrochloride (tamolarizine), a calcium entry blocker, on place learning impairment in rats with damage selective to the hippocampal CA1 subfield induced by transient forebrain ischemia. Tamolarizine was administered (40 mg/kg) immediately after 15-min brain ischemia. Place learning was tested in a task in which the rat was required to alternatively visit two places located diametrically opposite each other in an open field. The ischemia+saline group showed severe learning impairment in this task; their performance level was significantly inferior to that of the sham-operated group through the test period (30 days). Although the ischemia+tamolarizine group showed slight impairment of place learning during the course of this test, they later reached almost the same performance level as the sham-operated group. Selective neuronal loss in the CA1 subfield was much less in the ischemia+tamolarizine group than in the ischemia+saline group. These results indicate that tamolarizine treatment protects the hippocampus from ischemic brain damage and ameliorates place learning impairment.

Preparation of nanoparticles consisted of poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) and their evaluation in vitro

This study describes the preparation and the evaluation of biodegradable poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) copolymer (PLA-PEG-PLA) nanoparticles containing progesterone as a model drug. PLA and PLA-PEG-PLA copolymers, whose PEG content ranged from 5.2 to 25.8% (w/w), were polymerized in our laboratory. PEG with weight-average molecular weight (Mw) 6600 or 20 000 was introduced as a hydrophilic segment into a hydrophobic PLA homopolymer. A solvent evaporation method was used to prepare the nanoparticles. The drug trapping efficiencies were around 70% and the weight-averaged mean diameters of the nanoparticles were less than 335 nm. The amount of drug released increased as the PEG content and Mw of PLA-PEG-PLA copolymers increased and the total Mw of copolymers of nanoparticles decreased. The initial burst of drug release was reduced by removing the low Mw fraction from the polymer. During the release test, both the extent to which the copolymers were degraded and the size of the nanoparticles were increased slightly by increasing the content of PEG in the polymers. Drug release from the nanoparticles could potentially be controlled by changing the PEG content, PEG Mw and total Mw of the copolymer. The molecular weight distribution (Mw/Mn, Mn: number-average molecular weight) of copolymers was also an important factor for controlled release.

[Epidemiology of subacute sclerosing panencephalitis in Okinawa, Japan, 1970-1996]

In Okinawa, there were ten cases (7 male and 3 female) of subacute sclerosing panencephalitis (SSPE) from 1970 to 1996. All cases had a history of measles and none had received measles vaccination. The incidence of SSPE in Okinawa was 0.31 per million in 1970-1996. Being higher than other districts in Japan. Two cases contracted measles in 1973 and other three in 1990, showing a tendency to cluster.

Purification and properties of hydrogen sulfide oxidase from Bacillus sp. BN53-1

A hydrogen sulfide oxidase was purified to homogeneity from the heterotroph Bacillus sp. BN53-1 isolated from pig feces compost. The enzyme was found to be a monomer with a M(r) value of approximately 37 kDa. It required FAD for its activity, which was not replaced by FMN. The optimum reaction pH and temperature were 7.5 and 40 degrees C, respectively. The enzyme was stable between pH 6.0 and 7.0 and up to 30 degrees C. Its activity was stimulated by Ca2+ and Mn2+ and inhibited by Al3+, dithiothreitol, and 2-mercaptoethanol. The main product was elemental sulfur, and H2O2 was not detected. The N-terminal sequence of the enzyme showed similarity to other FAD-requiring enzymes.

Microencapsulation of hepatitis B core antigen for vaccine preparation

PURPOSE

To prepare poly(lactide-co-glycolide)(PLGA) microspheres containing recombinant hepatitis B core antigen (HBcAg; Mw = 3,600,000) by a w/o/w emulsion/solvent evaporation method and evaluate the possibility of this system as a potent long-acting carrier for hepatitis B core antigen in mice.

METHODS

Various additives had been incorporated in the internal aqueous phase during the process of microencapsulating HBcAg, HBcAg antigenicity in the medium extracted from the prepared microspheres were measured by ELISA. Shape confirmation of the HBcAg antigen was performed by a sucrose gradient velocity centrifugal technique. For in vivo study, prepared microspheres were administered subcutaneously to Balb/C mice, and the serum IgG level was determined by ELISA.

RESULTS

The inactivation of HBcAg by methylene chloride was dramatically reduced by the addition of gelatin (4-8% (w/v)) to the internal aqueous phase during the preparation. Further improvement of the loading efficiency to almost 61% resulted with cooling (4 degrees C). The prepared microspheres (4.27 microm+/-1.23 microm) containing 0.15% HBcAg displayed burst release (50-60% within 2 days). In subcutaneous inoculation, the adjuvant effect of PLGA microspheres was almost the same as that of the complete Freund's adjuvant. Whereas oral inoculation using the microspheres was not effective.

CONCLUSIONS

The pH of the added gelatin seemed to be the key to the stabilization of HBcAg from various stability tests and CD spectrum study. Finally, the possibility of using this system as a potent long-acting hepatitis B vaccine was demonstrated.

Pharmacokinetics of danaparoid sodium, dalteparin sodium and heparin determined by inhibitory effect on the activated coagulation factor X activity after single intravenous administration in rabbits

The inhibitory effect on the activated coagulation factor X activity (anti-Xa activity) in plasma and urine of danaparoid sodium (DAS, CAS 9005-49-6) was compared with that of dalteparin sodium (DLS, CAS 9041-08-1) and heparin (CAS 9005-49-6) after single intravenous administration at a dose of 640 anti-Xa U/kg to male rabbits. The elimination of half-life of DAS was 9.90 h and was 6.0 times longer than that of DLS and 16.5 times longer than that of heparin. The area under the plasma concentration-time curve (AUC) of DAS was 47.13 +/- 14.55 anti-Xa U.h/ml and was 2.4 times larger than that of DLS and 2.9 times larger than that of heparin. The urinary cumulative excretion of anti-Xa activity of DAS and DLS was 42.6 +/- 6.4% and 16.4 +/- 0.8% of dose, respectively, in 24 h after dosing, respectively. But the anti-Xa activity in urine was not detected at any sampling points after administration of heparin. DAS has a longer elimination half-life and a higher renal excretion of anti-Xa activity than that of DLS and heparin. Therefore, in comparison to DLS and heparin, it seems that the anticoagulant activity of DAS has a long duration.

The human chromosomal gene for necdin, a neuronal growth suppressor, in the Prader-Willi syndrome deletion region

Necdin is a growth suppressor expressed in virtually all postmitotic neurons in the brain. The human necdin gene, NDN, is maternally imprinted and deleted in the Prader-Willi syndrome, a neurobehavioral contiguous gene disorder. Here, we isolated and characterized the human chromosomal necdin gene and its promoter region. The necdin gene is intronless, and it encodes a protein of 321 amino acid residues, four residues shorter than mouse Necdin. By fluorescence in-situ hybridization analysis, the necdin gene was localized to chromosome 15q11.2-q12 within the Prader-Willi syndrome deletion region. CpG islands were found in a region extending from the proximal 5'-flanking sequence to the protein coding region. The 5'-flanking sequence, which lacks canonical TATA and CAAT boxes, possessed a promoter activity in postmitotic neurons derived from murine embryonal carcinoma P19 cells. Methylation in vitro of HhaI CpG sites in the promoter region reduced the transcriptional activity. These results suggest that the necdin gene is silenced through methylation of the CpG island encompassing its promoter region.

Biodegradable polyalkylcyanoacrylate nanoparticles for the delivery of oligonucleotides

Antisense oligonucleotides with base sequences complementary to a specific RNA can, after binding to intracellular mRNA, selectively modulate the expression of a gene. However, these molecules are poorly stable in biological fluids and are characterized by a low intracellular penetration. In view of using oligonucleotides as active molecules, the development of polymeric particulate carriers was considered. Oligonucleotides were associated with biodegradable polyalkylcyanoacrylate nanoparticles through the formation of ion pairs between the negatively charged oligonucleotides and hydrophobic cations. Oligonucleotides bound to these nanoparticles were found to be protected from nuclease attack in cell culture media and their cellular uptake was increased as the result of the capture of nanoparticles by an endocytotic/phagocytotic pathway. The in vivo pharmacokinetic profile of oligonucleotides free or associated with nanoparticles has been investigated after intravenous administration to mice and the stability of these molecules has been evaluated by original methodology based on the use of polyacrylamide gel electrophoresis (PAGE) followed by multichannel radioactivity counting. Stability in vivo in the plasma and in the liver was shown to be improved when the oligonucleotides were adsorbed onto the nanoparticles. These results obtained both in vitro and in vivo open exciting perspectives for the specific delivery of oligonucleotides to the liver, thus considering this approach for the treatment of liver diseases (e.g. liver metastasis or hepatitis).

Unclassified sclerosing bone dysplasia with osteopathia striata, cranial sclerosis, metaphyseal undermodeling, and bone fragility

Sclerosing bone dysplasias are diagnosed on the basis of a characteristic pattern of osteosclerosis and clinical manifestations; in many of them, cause and pathogenesis are still unknown. A 33-year-old man had five fractures of the humerus, tibiae, and femur as a result of mild traumatic incidents that occurred between the ages of 18 and 33 years as well as a remnant of rib fractures without apparent trauma on radiographs. His height was 158 cm (-2.2 SD). Radiographic evaluation showed cranial sclerosis, longitudinal striations in the metaphyses of the femur and tibia, fan-like striation in the ilium, metaphyseal widening in the femur and tibia, and sclerosis of the ribs. The blood chemistry findings, including serum calcium, phosphorus, and alkaline phosphatase, were normal. Biopsy from the ilium showed thick trabeculae composed of woven bone. The coexistence of osteopathia striata, cranial sclerosis, metaphyseal undermodeling, and bone fragility has not been recognized previously. Our case appears to represent a new form of sclerosing bone dysplasia.

Effect of Bacillus subtilis spore administration on activation of macrophages and natural killer cells in mice

The effect of Bacillus subtilis (strain A102) spores on the activation of murine macrophages and natural killer cells (NK) was examined. The macrophage activity and NK activity were enhanced by oral administration of A102 spores, and slightly enhanced by oral administration of culture supernatant. There was no difference in the results of macrophage activity and NK activity using other live or dead spores. The NK activity and macrophage activity were increased with increments of concentration up to 0.1 g per mouse, and both activities were decreased at concentration of more than 0.15 g per mouse. The NK activity was increased 1 and 2 days after oral administration of A102 spores, and the activity level 2 days after administration was about 3-fold higher than the level prior to treatment. Macrophage activity was also increased from 1 to 3 days after oral administration of A102 spores, and the activity level 3 days after administration was about 3-fold higher than the level prior to treatment. The induction of interferons at 1 day after oral administration in mouse serum was 5-fold higher than that in controls. These findings indicate that oral administration of A102 gave rise to the induction of interferons, and it is likely that macrophages and NK cells were activated by interferons.

Purification and properties of a sulfide-oxidizing enzyme from Streptomyces sp. strain SH91

A heterotrophic Streptomyces sp. strain SH91 isolated from pig feces compost had the ability to oxidize hydrogen sulfide to odorless substances. With several purification steps including ion-exchange and hydrophobic chromatographies, the hydrogen sulfide oxidizing enzyme was purified to a homogeneous form. The molecular mass was estimated to be 37 kDa by SDS–PAGE. The optimum reaction pH and temperature were 6.5 and 30 °C, respectively. The enzyme was stable between pH 6.0 and 8.0 and up to 40 °C. The enzyme was activated by Ba2+, Mg2+, and Ca2+ and inhibited by Mn2+, and Al3+. The main product was thiosulfate.Key words: hydrogen sulfide, heterotroph, Streptomyces, oxidizing enzyme, malodorous pollution.

Relationship between radical production and natural killer cytotoxic factor (NKCF) in canine natural killer (NK) cell-mediated cytotoxicity

The relationship between radical production and natural killer cytotoxic factor (NKCF) release via canine natural killer (NK)-mediated cytotoxic mechanism was examined. Radical production and NKCF release was induced in NK cells stimulated with either dead target cells, or their cytoplasmic membranes, as well as live target cells. Canine NKCF evoked target cell lysis but did not induce radical production. Radical production was inhibited by the addition of Tiron or n-propyl gallate, whereas NK-mediated cytotoxicity and NKCF release were only inhibited by the addition of n-propyl gallate. These results suggested that radical production and NKCF release may be induced by the contact and binding of NK cells to the target cell cytoplasmic membrane. Therefore, the release of NKCF from NK cells attached to the target cell cytoplasmic membrane may be associated with the production of radicals, especially hydroxyl radicals.

[The prevalence rate and etiology of severe motor and intellectual disabilities syndrome in Okinawa]

We studied sixty-three children of severe motor and intellectual disabilities syndrome aged between 3 and 5 years, who live in Okinawa. Severe motor and intellectual disabilities syndrome were defined as those who belong to classes 1 approximately 4 of Ohshima's classification (incapable of walking with IQs not more than 35). The prevalence rate was about 1.12/1,000 live births. Forty-four% of the total children belonged to class 1 of Ohshima's classification (bedridden and IQs less than 20). The factors were: congenital 31.7%, perinatal 38.1%, postnatal 14.3%, and unknown 15.9%. The perinatal factor was still relatively high as compared with the others.

Effect of chitosan implantation on activation of canine macrophages and polymorphonuclear cells after surgical stress

The effect of cotton type chitosan implantation under the skin on the immunological response mediated by macrophages and whole blood was evaluated by chemiluminescence (CL) in dogs. The number of white blood cells was significantly decreased until 120 hr after operation in the control group (p < 0.05), while chitosan implantation increased the number of white blood cells, particularly neutrophils, from 24 to 96 hr after implantation (p < 0.05). The CL response of whole blood in the control group seemed to be reduced at 48 and 96 hr after operation (p < 0.05), but in the chitosan groups it maintained higher activity until 120 hr after implantation (p < 0.05). The macrophage activity measured by CL assay in the control group was markedly decreased from 24 to 120 hr after operation, and that for the 5 mg/kg chitosan group was also decreased at 24 and 48 hr after implantation (p < 0.05), although high activity was observed from 72 to 120 hr after implantation (p < 0.05). Neither 5 mg/kg nor 10 mg/kg chitosan groups showed any reduction in CL response of macrophages after operation, and the 20 mg/kg chitosan group retained high CL response of macrophages until 120 hr after operation (p < 0.05). These findings suggest that chitosan may be an efficacious and useful immunopotentiator for preventation of immunosuppression after surgery.

[Percutaneous endoscopic gastrostomy in patients with swallowing difficulties--home care and long-term result]

We studied the possibility of home care of patients who are unable to swallow. Postsurgical complications during the short term (within a week), medium term (within a month) and long term (more than a month) were recorded along with survival time. We also retrospectively studied the number of patients who were discharged after percutaneous endoscopic gastrostomy from November 1989 to March 1995. The percentage of patients with short-term postsurgical complications was 12.1%. Vomiting was the most frequent complication during the medium term and the long term. The weekly rate of complication development (total complications number/total survival time) was highest in the short term and decreased year by year. It was lower in those who were discharged from the hospital than in those who were not discharged. The average survival time was 460.2 days (544.7 days: home care group, 419.0 days: hospital group). The one-year survival rate was 58%, and the two-year survival rate was 36%. One third (32.8%) of patients were cared for at home after gastrostomy (average duration of care at home: 338.5 days) and the average duration of care at home as a percentage of survival time was 58.8%. We conclude that Percutaneous endoscopic gastrostomy can improve the quality of life of patients who are unable to swallow, and may allow them to be cared for at home.

[MR imaging of cerebral palsy]

We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n = 11), spastic diplegia (n = 9), spastic hemiplegia (n = 2), double hemiplegia (n = 1), athetosis (n = 10) and mixed (n = 2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease.

Definitions of severely mentally and physically disabled children in Japan: do the differences affect the prevalence rates of these children?

The prevalence rate of severely mentally and physically disabled children (SDC) aged 6-15 years in Okinawa prefecture on 1 May 1989 was 0.74/1000 (143/192,038) according to Oshima's classification, compared with 0.89/1000 (170/192,038) according to the Ministry of Education's classification with minor modifications. The number of children in region classes 1, 2, 3 and 4 of Oshima's classification for SDC were 100, 34, 6 and 3, respectively. The difference (n = 27) between the total numbers of SDC according to the two classifications was mainly because of 21 children categorized as "walking with support' who were included as SDC according to the Ministry of Education's classification but not as SDC according to Oshima's classification. Only region class 1 of Oshima's classification corresponded with region class 25 of the Ministry of Education's classification. The results of the present study indicate that the differences between the two definitions of SDC affect the reported prevalence rates of SDC. Therefore, changing patterns in the prevalence of SDC should be assessed by serial surveys using the same method in each district.

Activation of canine monocytes and polymorphonuclear cells by serum thymic factor (FTS) in vivo

The effect of serum thymic factor (FTS) was evaluated from the immunoresponse augmented in canine monocytes and polymorphonuclear cells (PMN) using the chemiluminescence technique. FTS did not affect the number of leukocytes and differential count of leukocytes. CL activity of the whole blood was significantly elevated by FTS from 72 hr to 120 hr after administration (p < 0.05), and that at 96 hr after administration was about 3-fold higher than that before the administration. The CL response of PMN was significantly elevated by FTS administration from 24 hr to 96 hr after administration (p < 0.05), and that at 48 hr after administration was about 7-fold higher than prior treatment. FTS also significantly elevated the CL response of monocyte from 24 hr to 96 hr after administration (p < 0.01), and the CL count of monocyte in 24 hr and 48 hr was about 100-fold higher than that before FTS administration. These findings suggested that FTS may be efficacious and useful immuno-potentiator for canine monocytes and PMN.

Effect of renal failure on neurotoxicity of ranitidine in rats

We investigated the effect of acute renal failure on the neurotoxicity of ranitidine in rats. Experimental acute renal failure was produced by bilateral ureteral ligation. Ranitidine was infused into the ureter ligated (UL) and control rats at the rate of 3.25 mg/min through the jugular vein until the onset of clonic convulsion. In UL rats, the onset time of convulsion was shorter and ranitidine concentrations in plasma and cerebrospinal fluid (CSF) were lower than those of control rats. However, the ranitidine concentration in the brain at the onset of convulsion was not different between the UL and control rats. From these findings, we concluded that acute renal failure is one of the risk factors for ranitidine neurotoxicity, and the increased sensitivity to the drug on the central nervous system may contribute to the increased toxicity of ranitidine in renal failure.

Instability of bovine insulin in poly(lactide-co-glycolide) (PLGA) microspheres

Biodegradable poly(lactide-co-glycolide) (PLGA; 50/50) microspheres containing bovine insulin as a model protein was prepared by an oil-in-oil (o/o) emulsion solvent evaporation process. When aluminum tristearate (0.15% (w/v)) was employed as a dispersing agent, the loading efficiency of insulin was almost 100% and the yield was over 80%. The average diameter of the PLGA microspheres always ranged between 100 and 200 microns. Morphology study using a scanning electron micrograph showed smooth, spherical, fairly monodispersed PLGA microspheres containing insulin. In relation to release profile, the very low release rate of insulin was demonstrated (only 1% of insulin released after 7 d release test in pH 7.4 Tris buffer) for the PLGA microspheres. Nevertheless, the degradation of bovine insulin in PLGA microspheres was confirmed by high performance liquid chromatography. This degradation seemed to be caused by an acidic condition caused by poly(lactide-co-glycolide) polymer.

Pharmacokinetics and biodistribution of oligonucleotide adsorbed onto poly(isobutylcyanoacrylate) nanoparticles after intravenous administration in mice

PURPOSE

The goal of this study was to evaluate the ability of nanoparticles to be used as a targeted delivery system for oligonucleotides.

METHODS

Pharmacokinetic and tissue distribution were carried out in mice by measuring radioactivity associated to the model oligothymidylate 33P-pdT16 loaded to poly(isobutylcyanoacryate) (PIBCA) nanoparticles. In addition, we have used a TLC linear analyzer to measure quantitatively on a polyacrylamide gel electrophoresis, the amount of non degraded pdT16.

RESULTS

Organ distribution study has shown that nanoparticles deliver 33P-pdT16 specifically to the liver reducing its distribution in the kidney and in the bone marrow. Nanoparticles could partially protect pdT16 against degradation in the plasma and in the liver 5 min after administration, whereas free oligonucleotide was totally degraded at the same time.

CONCLUSIONS

Nanoparticles protect oligonucleotides in vivo against degradation and deliver them to the liver.

Characterization of natural killer cytotoxic factor (NKCF) from canine NK cells

We investigated the presence of canine natural killer cytotoxic factor (NKCF). Canine natural killer (NK) cell-mediated cytotoxicity measured by 51chromium (51Cr) release assay was found to be highest in the T-cell population, which was fractionated into the 35-40% Percoll fraction by discontinuous gradient centrifugation. The cytotoxicity of NKCF in the culture supernatant showed a similar tendency to NK activity. Release of NKCF was rapid after contact with target cells, and reached a plateau in 60 min. The cytotoxicity of NKCF could be detected within at least 15 min in coculture with CL-1 target cells, reaching a plateau in 60 min. We also characterized canine NKCF and found it to be a protein, which was stable against both heat and cold treatment. These findings suggest that canine NK cells release NKCF immediately after recognition and binding to the target cell, and that NKCF plays an important role in canine NK-mediated cytotoxicity.