Preparation of ceramic microspheres for in situ radiotherapy of deep-seated cancer

Radiotherapy is one of the most effective treatments for cancers. However, external irradiation provides only small doses to deep-seated cancers, and often causes damage to healthy tissues. It has been reported that 20-30 microm diameter 17Y(2)O(3)-19Al(2)O(3)-64SiO(2) (mol%) glass microspheres are useful for the in situ irradiation of cancers. Yttrium-89 (89Y) in this glass can be neutron bombarded to form the beta-emitter 90Y (half-life=64.1h). When injected in the vicinity of the cancer, such activated glass microspheres can provide a large localized dose of beta-radiation. The Y(2)O(3) content of the glass in the microspheres is limited to only 17 mol%. Chemically durable microspheres with a higher Y(2)O(3) content need to be developed. Phosphorus-31 (31P) with 100% natural abundance can also be activated by neutron bombardment to form the beta-emitter 32P (half-life=14.3d). Chemically durable microspheres containing a high phosphorus content are expected to be more effective for cancer treatment. We prepared pure Y(2)O(3) and YPO(4) microspheres using a high-frequency induction thermal plasma melting technique, and investigated the resulting structure and chemical durability. We successfully prepared smooth, highly spherical polycrystalline Y(2)O(3) and YPO(4) microspheres with diameters in the range 20-30 microm. Both the Y(2)O(3) and YPO(4) microspheres showed high chemical durability in saline solutions buffered at pH=6 and 7. These microspheres are expected to be more effective than the conventional glass microspheres for the in situ radiotherapy of cancer.     

Contribution of GABAergic inhibition to the responses of secondary vestibular neurons to head rotation in the rat

To assess the contribution of GABAA receptor-mediated inputs in control of vestibular responses of secondary vestibular neurons, we examined the effects of the GABAA receptor antagonists, bicuculline and picrotoxin, on these neurons in anesthetized rats. Horizontal canal-related secondary vestibular neurons were identified by their monosynaptic excitation from the ipsilateral vestibular nerve and by the modulation of their firing rate for head rotation. Responses to sinusoidal head rotation were recorded before and during iontophoretic application of the drugs. Application of bicuculline increased DC level of the responses (mean firing rate in each cycle) in all of the 10 neurons examined. In seven of these, the gain was increased along with the DC level, but the phase was virtually unaffected. Similarly, picrotoxin increased both the DC level (4/4) and the gain (3/4), but did not affect the phase. In the 10 neurons that increased the gain, the mean percent increase in the gain was 31% (8-54%). These results indicate that the majority of neurons received inhibitory inputs that were in phase with the excitatory inputs from primary afferents. This suggests that these neurons received GABAergic input of non-commissural origin, most likely from the flocculus.     

Genetic mapping of genes regulating the thymus size in back-cross rats between the laboratory BUF/Mna strain and the MITE strain derived from the wild rat, Rattus norvegicus

The thymoma prone BUF/Mna (B) rat is a useful model for Studying the genes responsible for thymus enlargement during the stage of young growth. Among the strains of rats, B rats have the largest thymuses at al stages of life. A locus, Ten-1 , which contributes to thymus enlargement in back-cross (BC) rats between the B and WKY/NCrj (W) strains, was mapped on chromosome 1. To determine the precise location of the bus, (B×(B×MITE)F1) BC rats were generated by crossing the B strain with the Inbred MITE (M) strain, which was established from captured, Japanese wild rats, and were examined by linkage study using polymerase chain reaction with 67 microsatellite markers. Linkages with thymus enlargements were found In genotypes of seven markers, BSIS, LSN, MYL2, IGF2, PBPC2, D1Mgh11 , and D1Mit6 , by X^2-test and Student's t -test, which confirmed the presence of the genetic locus associated with thymus enlargement, Ten-1 , in this region. Paradoxically, a suppressive locus, Tsu-1 , to thymus enlargement was also found on chromosome 3, showing linkages of phenotype of the small thymus with genotypes of SCN2A, CAT D3Mit16 , and D3Mit13 . By analyses of mapmaker/exp and mapmaker/qtl, Ten-1 was mapped at 4.6 cM proximal from IGF2 locus on chromosome 1 and Tsu-1 at 4.0 cM proximal from CAT locus on chromosome 3, respectively.     

Energetic characteristics of the new transthyretin variant A25T may explain its atypical central nervous system pathology

Transthyretin (TTR) is a tetrameric protein that must misfold to form amyloid fibrils. Misfolding includes rate-limiting tetramer dissociation, followed by fast tertiary structural changes that enable aggregation. Amyloidogenesis of wild-type (WT) TTR causes a late-onset cardiac disease called senile systemic amyloidosis. The aggregation of one of > 80 TTR variants leads to familial amyloidosis encompassing a collection of disorders characterized by peripheral neuropathy and/or cardiomyopathy. Prominent central nervous system (CNS) impairment is rare in TTR amyloidosis. Herein, we identify a new A25T TTR variant in a Japanese patient who presented with CNS amyloidosis at age 42 and peripheral neuropathy at age 44. The A25T variant is the most destabilized and fastest dissociating TTR tetramer published to date, yet, surprising, disease onset is in the fifth decade. Quantification of A25T TTR in the serum of this heterozygote reveals low levels relative to WT, suggesting that protein concentration influences disease phenotype. Another recently characterized TTR CNS variant (D18G TTR) exhibits strictly analogous characteristics, suggesting that instability coupled with low serum concentrations is the signature of CNS pathology and protects against early-onset systemic amyloidosis. The low A25T serum concentration may be explained either by impaired secretion from the liver or by increased clearance, both scenarios consistent with A25T's low kinetic and thermodynamic stability. Liver transplantation is the only known treatment for familial amyloid polyneuropathy. This is a form of gene therapy that removes the variant protein from serum preventing systemic amyloidosis. Unfortunately, the choroid plexus would have to be resected to remove A25T from the CSF-the source of the CNS TTR amyloid. Herein we demonstrate that small-molecule tetramer stabilizers represent an attractive therapeutic strategy to inhibit A25T misfolding and CNS amyloidosis. Specifically, 2-[(3,5-dichlorophenyl)amino]benzoic acid is an excellent inhibitor of A25T TTR amyloidosis in vitro.     

Effect of hepatocyte growth factor on sperm motility

PROBLEM: Hepatocyte growth factor (HGF) exists abundantly in seminal plasma and its receptor, c-met, is expressed on spermatozoa. Considering its motogenic activity, we speculated that HGF might affect the movement ability of spermatozoa. METHODS: Recombinant HGF was added to washed spermatozoa and their movements were analyzed using a computer-assisted sperm analyzer. The concentration of HGF in the seminal plasma of infertile patients (n = 83) was measured by ELISA, and the data were compared with their hormonal profile and semen parameters. RESULTS: The HGF physiological concentration (1 ng/mL) maintained the motility of sperm after a long incubation, though the difference was not statistically significant. Recombinant HGF did not affect the linearity or frequency of movement, which suggested that it does not evoke the hyperactivation of spermatozoa. The concentration of HGF in seminal plasma did not correlate with any clinical parameter of the patients. CONCLUSIONS: These findings contradict the theory that HGF controls the movement of sperm. The main role of this axis in the male reproductive system might be maturation in the epididymis.     

GRO-alpha in Human Serum: Differences Related to Age and Sex

PROBLEM: Human GRO-alpha (GRO-α) is a new member of the chemokine family that is supposed to play an important role in inflammatory and immune reactions. We established a sandwich enzyme-linked immunoassay (ELISA) system with polyclonal antibodies against human GRO-α and investigated the serum level of healthy donors to establish normal ranges for this chemokine in adults. METHODS: GRO-α concentrations were measured cross-sectionally in the sera of 240 healthy adults. The variability of serum GRO-α levels was also measured in normal volunteers, samples from whom were obtained by sequential venipunctures or by a small plastic cannula with a heparin-saline lock, to determine short-term variability. RESULTS: Whereas there was no difference between the concentration of human GRO-α from men (logarithmic mean, 77.6 pg/ml, n = 120) and that from women with normal menstrual cycles (log mean, 71.6 pg/ml, n = 73), the concentration from postmenopausal women (log mean 45.0 pg/ml, n = 31) was lower than that from women with normal menstrual cycles (log mean 71.6 pg/ml, n = 73). However, we could not detect any significant difference between healthy donors' serum levels and those of donors with acute inflammation. Fewer variations were recognized in the case of the sequential venipunctures method than in that of the heparin-saline lock method. CONCLUSION: We found that the GRO-α concentration of postmenopausal women was significantly lower than that of women with normal menstrual cycles. These results suggest the GRO-α serum levels of normal healthy women may have some correlation with sex hormones.     

The T-cell receptor alpha, beta and gamma polymorphism in Japanese

Polymorphism in the genes encoding the alpha (alpha), beta (beta) and gamma (gamma) chains of the human T-cell receptors was analyzed both in population and family studies. Against twelve unrelated Japanese, several out of the 15 restriction endonucleases tested, revealed restriction fragment length polymorphism. The segregation of the polymorphic fragments were confirmed among 15 members of three families. In most of the cases paternal and/or maternal haplotypes could be assigned. By testing the polymorphic enzymes among the random healthy Japanese, the frequency of each polymorphic fragment was then determined. Although the polymorphism found in this study was similar to that reported in Caucasians, some differences were observed. Such differences are discussed. The restriction fragment length polymorphism in both population and family studies, derived from alpha, beta and gamma chains of the T-cell receptor found in this report, might be useful markers for genetic analysis of the T-cell function in relation to immunological disorders.     

Analysis of proteins in urinary tract stones and urine of urolithic patients

In order to investigate the mechanism of urinary tract stone formation, we analyzed protein components in urine and the stone. Urinary proteins of healthy subjects and urolithic patients as well as protein components urinary tract stone of the urolithic patients were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Electrophoretic patterns of urinary proteins of the patients differed from those of healthy subjects after separating protein patterns into those larger than 66kDa or smaller than 30kDa. Protein constituents of urinary tract stone were mainly separated into 18 bands ranging from 26.8 to 143 kDa. Major bands among these 18 bands differed among stones from different patients. On western blotting, the developed intensities of Tamm-Horsfall protein (THP) were fainter than those of healthy subjects. Whereas intensities of albumin (ALB) were stronger than those of healthy subjects. Moreover, blotting patterns of THP of the patients on non-reducing SDS-PAGE were obviously broad. Thus, we suggest that analysis of fractionated urinary proteins or protein components of urinary tract stone may provide a tool for monitoring the prognosis or relapse in the patients.