Varying Ti-6Al-4V surface roughness induces different early morphologic and molecular responses in MG63 osteoblast-like cells

Osteoblast response to Ti implants depends not only on the chemistry of the implant but also on the physical properties of the implant surface, such as microtopography and roughness. This study was undertaken to examine early changes in cell morphology and gene expression during the early phase of osteoblast interaction with titanium alloy (Ti-6Al-4V) surfaces of two different roughnesses. MG63 osteoblast-like cells were cultured for 2, 6, 24, and 72 h on smooth (Ra=0.18+/-0.03 microm) and rough (Ra=2.95+/-0.23 microm) Ti-6Al-4V surfaces. Changes in cell proliferation were assessed by measuring cell number after 72 h in culture. Morphological characteristics were observed by scanning electron microscopy after 2, 6, and 24 h of culture. Changes in gene expression for extracellular signal-regulated kinase 2 (Erk2), type I collagen (alpha2[I] collagen), phospholipase C-gamma2 (Plc-gamma2), and beta-actin were measured by RT-PCR after 6 and 24 h in culture. Cell number was significantly higher on the smooth surface. In scanning electron micrographs, cells on smooth Ti-6Al-4V were spherical and raised up from the surface after 2 h in culture. In contrast, cells on the rough surface adopted an irregular, elongated shape that spanned across pits in the surface. At 24 h, cells on the smooth surface had flattened, become elongate, and covered the surface. In contrast, cells on the rough surface appeared more differentiated in shape and the margins of the cells were irregular, with many processes extending out, following the contour of the surface. Of the genes examined, only Erk2 and beta-actin showed a change in expression with surface roughness. Both genes were upregulated (p<0.05) on the rough surface at 6 h. These results indicate that Ti-6Al-4V surface roughness affects osteoblast proliferation, morphology, and gene expression, and that these effects can be measured after periods as short as 2-6 h.

The 10th and 11th residues of short length N-terminal PTH(1-12) analogue are important for its optimum potency

The 10th and 11th residues of parathyroid hormone PTH(1-12) analogues were substituted to study the structure and function of PTH analogues. The substitution of Ala(10) of [Ala(3,10,12)(Leu(7)/Phe(7))Arg(11)]rPTH(1-12)NH(2) with Glu(10) and/or the Arg(11) with Ile(11) markedly decreased cAMP generating activity. Data from circular dichroism (CD) and the nuclear magnetic resonance (NMR) structural analysis of [Ala(3,10,12)(Leu(7)/Phe(7))Arg(11)]rPTH(1-12)NH(2) revealed tight alpha-helical structures, while the Glu(10) and/or Ile(11) substituted analogues showed unstable alpha-helical structures. We conclude that 10th and 11th residues are important for stabilizing its helical conformation and that destabilization of the alpha-helical structure, induced by substituting the above residues, remarkably affect its biological potency.

Identification of a novel HLA-DRB1*12 allele (DRB1*1210) in the Korean population

At least 11 HLA-DRB1*12 alleles have been identified to date. We report a new HLA-DRB1*12 allele, DRB1*1210, that was identified in the Korean population. This new allele differs from HLA-DRB1*120101 by a single nucleotide at position 40 (G-->A) in exon 1 that falls within codon--16 (GTT-->ATT). This change results in a single valine to isoleucine amino acid alteration.

Influence of irradiation and storage on the quality of ready-to-eat turkey breast rolls

Influence of irradiation and storage on the quality of ready-to-eat (RTE) turkey breast rolls was investigated. Commercial oven roasted turkey breast rolls purchased from local stores were sliced and vacuum packaged. The sliced samples were randomly divided into 3 groups and irradiated at 0, 1.0, or 2.0 kGy using a linear accelerator. Color, 2-TBA-reactive substances (TBARS), sensory characteristics, and volatiles were evaluated at 0, 7, and 14 d of storage. Irradiation increased color a* value of turkey breast rolls. Irradiation and storage did not influence TBARS values. Sensory evaluation showed that irradiation significantly increased sulfury flavor. Because a dramatic increase in sulfur compounds was detected in irradiated samples, the sulfury flavor should be due to the sulfur compounds formed during irradiation. Irradiation also increased the amounts of acetylaldehyde, 2-methyl butanal, 3-methyl butanal, benzene, and toluene. It was concluded that irradiation significantly influenced the odor and flavor of RTE turkey breast rolls under vacuum packaging conditions. Therefore, strategies to prevent negative changes in the quality of irradiated RTE turkey breast rolls are needed.

Value of chest radiography in a tuberculosis prevention programme for HIV-infected people, Botswana

To exclude tuberculosis, WHO/UNAIDS recommends considering medical history, symptom screen, and chest radiograph before starting tuberculosis prevention in people infected with HIV. The value of a chest radiograph for this purpose is unknown. We prospectively assessed 935 HIV-infected outpatients seeking isoniazid preventive therapy. Of 935 patients, 692 (74%) had no signs or symptoms of tuberculosis. Of these 692, 123 (18%) were lost during the chest radiograph process, and one (0.2%) of the remaining 563 was diagnosed with tuberculosis on the basis of the chest radiograph. A screening chest radiograph should not be required routinely for asymptomatic people taking isoniazid as preventive treatment in settings able to screen for signs and symptoms of tuberculosis.

The validity of HIV testing using sputum from suspected tuberculosis patients, Botswana, 2001

SETTING

The World Health Organization recommends that sentinel HIV surveillance be conducted on tuberculosis patients. However, serum HIV testing is complicated in the TB clinic context, and may not be acceptable to patients.

DESIGN

To determine the utility of the OraQuick HIV-1/2 Assay for the detection of HIV antibodies in sputum, we consecutively enrolled adult in-patients in Botswana who had sputum sent for acid-fast bacilli testing and serum sent for HIV ELISA testing. OraQuick HIV-1/2 Assay was applied to gingival secretions according to manufacturer's guidelines, and was also dipped into sputum specimens. A subset of 60 sputum specimens was also serially tested up to 72 hours after collection.

RESULTS

Of 377 patients, 84% were HIV-positive by serum ELISA. Compared with serum ELISA, the OraQuick HIV-1/2 Assay detected HIV in gingival secretions with 98.4% sensitivity and 98.3% specificity (95%CI 97-99 and 92-100, respectively), and 97.1% sensitivity and 98.3% specificity on initial sputum specimens (95%CI 95-99 and 92-100, respectively). OraQuick HIV-1/2 Assay performance on sputum declined slightly when tested up to 72 hours after collection.

CONCLUSIONS

When applied to sputum specimens, the OraQuick HIV-1/2 Assay demonstrates sensitivity and specificity comparable to its intended application on gingival secretions. This novel testing method will be valuable in anonymous sentinel HIV surveillance surveys among tuberculosis patients.

p53 protein regulates the effects of amifostine on apoptosis, cell cycle progression, and cytoprotection

To determine the role of p53 protein on the cellular effects of amifostine, we used molecularly engineered HCT116 colon cancer cells in which the p53 gene was inactivated by targeted homologous recombination or p53 protein was degraded by high-level expression of papillomavirus E6 protein. Amifostine induced a G1 arrest and protected against paclitaxel toxicity in p53-proficient but not in p53-deficient cells. In the absence of p53 protein, amifostine enhanced the cytotoxicity of paclitaxel. In addition, treatment of HCT116 cells with amifostine alone resulted in apoptotic cell death. Compared with p53-deficient cells, p53-proficient cells exhibited low-level resistance to amifostine-induced apoptosis. Amifostine induced the expression of p53 protein in p53-proficient cells and the expression of p21 protein in both p53-proficient and -deficient cells. These findings indicate that amifostine-induced G1 arrest and cytoprotection are mediated via a pathway that is dependent on p53 protein and that amifostine-induced expression of p21 protein is not sufficient to sustain a G1 arrest or to mediate cytoprotection. In addition, these findings identify p53 protein as a mechanism of resistance to amifostine-induced apoptosis.British

A dominant negative PPARgamma mutant shows altered cofactor recruitment and inhibits adipogenesis in 3T3-L1 cells

AIMS/HYPOTHESIS

PPARgamma, a member of the nuclear hormone receptor family of transcription factors, plays a key role in adipocyte differentiation and insulin sensitivity. The aim of this study was to identify a potential dominant negative murine PPARgamma mutant and to characterize the in vitro functional properties of this mutant.

METHODS

In vitro transient transfections and mammalian two-hybrid assays in TSA201 cells were used to characterize the transcriptional activity of the L466A mutant and to study the molecular interaction of transcriptional cofactors with the L466A mutant in an attempt to elucidate the mechanism of its dominant negative activity. Adenoviral constructs expressing PPARgamma wild-type (AdWT) or the L466A mutant (AdL466A) were infected into the murine 3T3-L1 cell line to study the mutant's effect on adipogenesis.

RESULTS

The L466A mutant alone is transcriptionally defective. However, it retains DNA binding and inhibits the ligand-dependent and -independent activity of the wild-type receptor, consistent with dominant negative properties. In mammalian two-hybrid studies, the L466A mutant does not bind nuclear receptor coactivators. However, it more avidly recruits corepressors due to enhanced binding to the corepressor ID1 domain, leading to pronounced transcriptional repression. The AdL466A mutant inhibits adipogenesis induced by either a differentiation cocktail or by thiazolidinedione ligand. AdL466A infection also blocked the upregulation of the adipocyte marker genes aP2 and adipsin.

CONCLUSION

We conclude that the L466A PPARgamma mutant possesses potent dominant negative activity based on preferential corepressor recruitment and it inhibits adipogenesis and the expression of adipocyte-specific genes.

Upregulation of c-Kit receptor and stem cell factor in cerebellar inhibitory synapses in response to kainic acid

Neuronal stimulation was induced in rats by systemic administration of kainic acid (KA) to determine if such stimulation is responsible for changes in the expression patterns of c-Kit and stem cell factor (SCF) in cerebellar synapses between inhibitory interneurons and Purkinje cells. Using immunocytochemistry and immunoblotting analyses, we demonstrate that c-Kit receptor tyrosine kinase and its ligand SCF are present on the pre- and postsynaptic sides of inhibitory synapses on Purkinje cells. These proteins are upregulated during the first 48 hr after KA treatment, whereas their levels fall below that of the control by 1 week and remain as such thereafter. Expression of both c-Kit and SCF are significantly elevated in the Purkinje cell layer 24 hr after KA administration, and the Purkinje cell layer exhibits a loss of calbindin D-28K immunoreactivity. Expression of c-Kit in basket cell axon terminals is activated until 48 hr after KA treatment, suggesting the transient participation of c-Kit receptor tyrosine kinase in the maintenance of these axonal terminals. Also during the first 48 hr after KA treatment, SCF levels increase in axonal processes of Purkinje cells, and these SCF-positive axons correlate with c-Kit-positive pinceau structures. The increased expression of c-Kit and SCF in response to KA-induced neuronal stimulation may indicate that c-Kit receptor tyrosine kinase and its ligand SCF function in the inhibitory synapse between cerebellar interneurons and Purkinje cells, and that this role is most pronounced during the first 48 hr after KA treatment.

No association of the TGF-beta1 gene polymorphisms with the renal progression in autosomal dominant polycystic kidney disease (ADPKD) patients

BACKGROUND

Two genetic loci, PKD I and PKD2, have been identified as being responsible for ADPKD, and PKD1 is known to be associated with a poor prognosis. However, the presence of an intrafamilial study clinical diversity suggests that there are disease-modifying loci. Because the mechanism ofthe renal failure in ADPKD includes a cystic growth and tubulointerstitial atrophy and fibrosis, we studied the associations between 2 polymorphisms in the TGF-beta1 gene, which are known to be associated with chronic tubulointerstitial inflammation, and ADPKD progression in Korean patients.

PATIENTS AND METHODS

One hundred and twenty-five individuals who had ADPKD and 47 normal control subjects were genotyped by PCR-RFLP, the T869C (Leu10Pro) variant of TGF-beta gene leader sequence was discriminated with MspA1I and the G915C (Arg25Pro) variants with Bg1I. Statistical significances were determined using the Chi-square test.

RESULTS

The distribution of the alleles for the TGF beta1 Leu10Pro polymorphism in ADPKD was: T 54%, C 46%, which was similar to the Korean (56: 44, p = 0.887) and Western controls (65: 35). In addition, no differences were found between the ESRD and the non-ESRD groups (p = 0.888) or the early hypertension and the normotension groups (p = 0.249). The distribution of alleles for the TGF beta1 Arg25Pro polymorphism showed only the GG type which was different from the Western population controls (G:C = 90:10, p = 0.000).

CONCLUSIONS

Our results suggest that the polymorphism at Arg25Pro of TGF-beta1 in the Korean population has an allele distribution different from that ofthe Western population and that the polymorphism at Leu10Pro of TGF-beta1 has no association with the renal progression in Korean ADPKD patients.

Adult-to-adult living donor liver transplantation at the Asan Medical Center, Korea

Between February 1997 and December 2001, 311 adult-to-adult living donor liver transplants (A-A LDLTs) were performed at the Asan Medical Center for patients above 20 years of age. Indications for A-A LDLT were: chronic hepatitis B (203), chronic hepatitis C (5), hepatocellular carcinoma (64), alcoholic cirrhosis (9), cryptogenic cirrhosis (4), secondary biliary cirrhosis (5), primary biliary cirrhosis (1), Wilson' s disease (2), autoimmune hepatitis (1), hepatic tuberculosis (1), cholangiocarcinoma (1), fulminant hepatic failure (14) and primary non-function of cadaveric liver graft (1). Of 311 A-A LDLTs, 36 were of medical high urgency, 20 were for acute and subacute hepatic failure, 15 were for hepato-renal syndrome and 1 was for primary non-function. Recipient age ranged from 27 to 64 years. Donor age ranged from 16 to 62 years. There was no donor mortality. Implanted liver grafts were categorized into seven types: 175 modified right lobe (MRL), 70 left lobe, 32 right lobe, 20 dual grafts, 10 left lobe plus caudate lobe, three extended right lobe and one posterior segment. In MRL, the tributaries of the middle hepatic vein were reconstructed by interpositioning a vein graft. Indication for dual graft implantation was the same as single graft A-A LDLT, and four of 20 were emergency cases. Of 20 dual grafts, 14 received two left lobes, four received a left lobe and a lateral segment, one received a right lobe and a left lobe and one received a lateral segment and a posterior segment. Graft volume ranged from 28% to 83% of the standard liver volume of the recipients. There were 33 (10.6%) in-hospital mortalities (< 4 months) among the 310 patients after 311 A-A LDLTs. Of the 36 patients receiving emergency transplants, 31 survived. These encouraging results justify the expansion of A-A LDLT in coping with increasing demands, even in urgent situations. We have aimed to introduce the establishment of the efficacy of A-A LDLT in various end-stage chronic and acute liver diseases, as well as new technical advances to overcome small graft-size syndrome by using dual-graft implantation and MRL, both of which were first developed in our department.

Pharmacokinetics, stability, and blood partition of DA-8159, a new phosphodiesterase V inhibitor

The pharmacokinetics of DA-8159, a new phosphodiesterase V inhibitor, after 1 min intravenous, 30 mg/kg, and oral, 30 mg/kg, administration of the drug to rats, the stability of DA-8159 in various pH solutions ranging from 1 to 13, and human and rat plasma and urine, and the blood partition of DA-8159 between plasma and blood cells of rabbit were evaluated. After intravenous administration, DA-8159 was eliminated fast with the mean total body clearance of 126 ml/min/kg, and was almost completely metabolized in rats; 5.98% of intravenous dose of DA-8159 were excreted unchanged in 24-hr urine. The extent of absolute oral bioavailibility of DA-8159 was approximately 25%. The apparent volume of distribution at steady state was considerably large, 15048 ml/kg, suggesting that DA-8159 has a good affinity to rat tissues. DA-8159 was relatively stable in various pH solutions, and human and rat plasma and urine for up to 48 h incubation in a water-bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. DA-8159 reached equilibrium fast (within 30 sec mixing manually) between plasma and blood cells of rabbit blood and the plasma-to-blood cell concentration ratios were independent of initial blood concentrations of DA-8159, 1, 5, and 10 microg/ml, when the rabbit whole blood was incubated for up to 120 min; the ratios were in the range of 0.662-0.812. There was no in vitro 'blood storage effect' in the plasma concentration of DA-8159.

Effects of neostigmine on the pharmacokinetics of intravenous parathion in rats

It was reported that the area under the plasma concentration-time curve from time zero to time infinity (AUC) of parathion was significantly smaller and the time-averaged total body clearance (CL) of parathion was significantly faster after intravenous administration of parathion to rats pretreated with dexamethasone than those in control rats. This was supported by significantly faster intrinsic clearance of parathion to form paraoxon in hepatic microsomal fraction of rats pretreated with dexamethasone. The above data suggested that parathion was metabolized to paraoxon by dexamethasone-inducible hepatic cytochrome P450 (CYP) 3A in rats. The purpose of this study is to explain the protective effects of neostigmine against paraoxon toxicity by suppressing CYP3A and hence decreasing formation of toxic metabolite, paraoxon by neostigmine. The pharmacokinetic changes of parathion and its active metabolite, paraoxon, were investigated after intravenous administration of parathion, 3 mg/kg, to control Sprague-Dawley rats and the rats pretreated with neostigmine (200 microg/kg, intraperitoneal injection 30 min before parathion administration). After 1-min intravenous infusion of parathion to rats pretreated with neostigmine, the AUC of parathion (65.1 versus 74.3 microg min/ml) was significantly greater and the CL of parathion (45.1 versus 40.4 ml/min/kg) was significantly slower than those in control rats. Based on in vitro hepatic microsomal studies, neostigmine inhibited significantly the erythromycin N-demethylase activity (1.03 versus 0.871 nmol/mg protein/min), mainly mediated by hepatic cytochrome P450 3A in rats. The above data suggested that the formation of paraoxon was inhibited in rats pretreated with neostigmine by inhibiting CYP3A.

Three novel mutations of the PKD1 gene in Korean patients with autosomal dominant polycystic kidney disease

Mutations at the PKD1 locus account for 85% of cases of the common genetic disorder called autosomal dominant polycystic kidney disease (ADPKD). Screening for mutations of the PKD1 gene is complicated by the genomic structure of the 5'-duplicated region encoding 75% of the gene. To date, more than 90 mutations of the PKD1 gene have been reported in the European and American populations, and relatively little information is available concerning the pattern of mutations present in the Asian populations. We looked for mutations of the PKD1 gene in 51 unrelated Korean ADPKD patients, using polymerase chain reaction (PCR) with primer pairs located in the 3' single-copy region of the PKD1 gene and by single-strand conformation polymorphism (SSCP) analysis. We found three novel mutations, a G to A substitution at nucleotide 11012 (G3601S), a C to A substitution at nucleotide 11312 (Q3701X), and a C to T substitution at nucleotide 12971 (P4254S), and a single polymorphism involving a G to C substitution at nucleotide 11470 (L3753L). These mutations were not found in control individuals, and no other mutations in the 3' single-copy region of the PKD1 gene of patients with these mutations were observed. In particular, P4254S segregated with the disease phenotype. The clinical data of affected individuals from this study, and of previously reported Korean PKD1 mutations, showed that patients with frameshift or nonsense mutations were more prone to develop end-stage renal failure than those with missense mutations. Our findings indicate that many different PKD1 mutations are likely to be responsible for ADPKD in the Korean population, as in the Western population.

Synthesis of SnO2 nanoribbons by a carbothermal reduction process

This communication describes, for the first time, the growth of SnO2 nanoribbons by a controlled carbothermal reduction process. An analysis of the transmission electron microscopy image revealed that these nanoribbons have a well-defined shape, with a typical width in the range of 70-300 nm. In general, the nanostructured ribbons were more than 100 microns in length. The results reported here support the hypothesis that this ribbon-like nanostructured material grows by a vapor-solid process. This study introduces two hypotheses to explain the SnO2 nanoribbon growth process.

Localization of the muscular dystrophy AM locus using a chicken linkage map constructed with the Kobe University resource family

A chicken linkage map, constructed with the Kobe University (KU) resource family, was used to locate the genetic locus for muscular dystrophy of abnormal muscle type (AM). The KU resource family is a backcross pedigree with 55 offspring produced from the mating of a White Leghorn F-line (WL-F) male and a hybrid female produced from a cross between the WL-F male and a female of the Fayoumi OPN line who was homozygous for the AM gene. In total, 872 loci were genotyped on the pedigree; 749 (86%) were informative and mapped to 38 linkage groups. These informative loci included 649 AFLPs, 93 MS, three functional genes, the AM locus, sex phenotype, and two red blood cell loci. The remaining 123 markers were unlinked. Nineteen of the 38 KU linkage groups were assigned to macrochromosomes 1-8 and 11 microchromosomes including chromosome W, while 19 linkage groups were unassigned. The total map was 3569 cM in length, with an average marker interval of 4.8 cM. The AM locus was mapped 130 cM from the distal end of chromosome 2q.

Ionomycin restores taurine transporter activity in cyclosporin-A treated macrophages

Taurine is accumulated at high concentrations in various tissues. The taurine transporter (TAUT) is responsible for the transportation of taurine in the cell. The transporter is affected by various stimuli to maintain cell volume. Macrophage cell volume varies in its activated states. In our experiment, it was found that the murine macrophage cell line, RAW264.7, expressed TAUT protein in its membrane. Its transporting activities could be blocked by beta-amino acid such as beta-alanine, but not by alpha-amino acids in this cell line, when assessed in RAW264.7 cells under the influence of immunosuppressive reagents, the activity of the TAUT was decreased by treatment with rapamycin (RM) or cyclosporin A (CSA). However, when ionomycin (IM) was added to this system, TAUT activity was recovered only in CSA-treated cells, in a concentration-dependent manner, in order to inhibit voltage gated Ca2+ channels, calmidazolium was added to the RAW264.7 cell line. Treatment of the cells with calmidazolium completely blocked TAUT. Furthermore, addition of IM to this system resulted in recovery the activity of TAUT again. When we added phorbol myristyl acetate (PMA) to the cell line, secretion of nitric oxide (NO) was increased 4-fold and the TAUT activity was decreased 5-fold. However, the addition of N-nitro L-arginine methyl ester (L-NAME), an inducible NO synthase (iNOS) inhibitor, to the PMA-treated cells induced recovery of TAUT activity. These results showed that the activity of TAUT was sensitive to both the intracellular concentrations of Ca2+ and NO.

Serum ascorbic acid and protein calorie malnutrition in continuous ambulatory peritoneal dialysis patients

Protein calorie malnutrition (PCM) is a major predictor of morbidity and mortality in continuous ambulatory peritoneal dialysis (CAPD) patients. Oxidative stress has been implicated as a contributory cause. The relative lack of ascorbic acid, a plasma antioxidant, has been reported in CAPD patients. We therefore examined the correlation between serum ascorbic acid (SAA) and parameters of PCM in a cross-sectional study of 50 clinically stable adult CAPD patients. The mean age of the study group was 61 +/- 11 years; 48% of the patients were male; and 64% had diabetes. The parameters assessed were SAA, serum albumin (S Alb), body mass index (BMI), subjective global assessment (SGA), and lean body mass (LBM). The results (mean +/- standard deviation) were: SAA, 9.44 +/- 8.79 mg/L; S Alb, 31.6 +/- 4.9 g/L; BMI, 24.4 +/- 3.4; LBM, 0.66 +/- 0.14 kg/kg body weight; SGA, 9 of 50 were considered mildly-to-moderately malnourished (the rest were well-nourished). A significant correlation (p < 0.001) was found between SAA and S Alb only with SAA < or = 9 mg/L. No correlation was seen between SAA (at any level) and BMI or LBM. The SAA was not significantly different between the groups as graded by SGA. The data suggest that the mechanisms for low serum albumin in these patients may be related to the role of ascorbic acid as a plasma antioxidant.

Oral intake and serum levels of ascorbic acid in continuous ambulatory peritoneal dialysis patients

Oral intake of ascorbic acid is essential for optimum health in human beings. Continuous ambulatory peritoneal dialysis (CAPD) patients have an increased need for ascorbic acid, because of increased loss through dialysate, reduced intake owing to nausea and loss of appetite, and increased oxidative stress. However, optimum intake is still controversial. We studied 50 clinically stable patients to determine the relationship between oral ascorbic acid intake and serum ascorbic acid (SAA) level. Total oral intake ranged from 28 mg daily to 412 mg daily. Only one patient had an oral intake of ascorbic acid below 60 mg per day. The SAA levels ranged from 1 mg/L to 36.17 mg/L. Although a strong correlation existed between intake and SAA (p < 0.001, R2 = 0.47), the variation in SAA at any given intake level was wide. Of the studied patients, 62% had an SAA < 8.7 mg/L, 40% had an SAA < 5.1 mg/L (below the level in a healthy population), and 12% had a level below 2 mg/L (scorbutic). None of the patients demonstrated clinical manifestations of scurvy. Our results show that, in CAPD patients, ascorbic acid deficiency can be reliably detected only with SAA measurements, and oral intake may influence SAA level. To maintain ascorbic acid in the normal range for healthy adults, daily oral intake needs to be increased above the U.S. recommended dietary allowance to 80-140 mg.

Light- and electron-microscopic analysis of neuropeptide Y-immunoreactive amacrine cells in the guinea pig retina

We investigated the morphology and synaptic connections of neuropeptide Y (NPY)-containing neurons in the guinea pig retina by immunocytochemistry, using antisera against NPY. Specific NPY immunoreactivity was localized to a population of wide-field and regularly spaced amacrine cells with processes ramifying mainly in stratum 1 of the inner plexiform layer (IPL). Double-label immunohistochemistry demonstrated that all NPY-immunoreactive cells possessed glutamic acid decarboxylase 65 immunoreactivity. The synaptic connectivity of NPY-immunoreactive amacrine cells was identified in the IPL by electron microscopy. The NPY-labeled amacrine cell processes received synaptic input from other amacrine cell processes and bipolar cell axon terminals in stratum 1 of the IPL. The most frequent postsynaptic targets of NPY-immunoreactive amacrine cells were other amacrine cell processes. Synaptic outputs to bipolar cells were also observed in a small number of cases. This finding suggests that NPY-containing amacrine cells may influence inner retinal circuitry in stratum 1 of the IPL, thus mediating visual processing.

Extraocular muscle changes after cryotherapy for retinopathy of prematurity and the development of strabismus in premature infants

To find out whether the cryotherapy for the treatment of the retinopathy of prematurity (ROP) causes structural changes of the extraocular muscle (EOM), and also whether the changes are related with the occurrence of strabismus. To examine the acute stage change, we conducted a transconjunctival cryotherapy around the superior rectus muscle of a rabbit and resected it 0, 3, 7, 14, and 28 days after the cryotherapy. In observing chronic changes, we first categorized patients who had an esotropia surgery into groups, one of which combined prematurity and cryotherapy and one group affected by prematurity but without having had cryotherapy. Then we compared the change of EOM with that of a fullterm infant group. In a rabbit, edema, acute inflammatory cells and a large amount of degenerated muscle fibers were observed immediately after the cryotherapy and on the 3rd day. On the 7th day, regenerated muscle fibers were observed and on the 14th day, the inflammatory cells decreased and the amount of regenerated muscle fiber increased. On the 28th day, abnormal findings were not observed any more and the muscle was found to be normal. When chronic changes of EOM in human on 1 1/2 to 8 1/2 years after cryotherapy, there were no abnormal findings observed in three groups. From the study, we can infer that cryotherapy can cause acute inflammation and necrosis of muscle fiber but such an acute change will improve and does not result in structural change in the long term. Therefore, the occurrence of strabismus in patients with ROP is considered to be attributable to reasons other than injury of EOM.

The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases

PURPOSE

To report on the use of the laryngeal mask airway (LMA) for elective Cesarean section in 1067 consecutive ASA I-II patients preferring general anesthesia.

METHODS

Patients were excluded if they had pharyngeal reflux, a pre-pregnancy body mass index >30, or had a known/predicted difficult airway. Patients were fasted for six hours and given ranitidine/sodium citrate. A rapid sequence induction was performed with thiopentone and suxamethonium. The LMA was inserted by experienced users. Anesthesia was maintained with N(2)O and 50% O(2) and a volatile agent. Cricoid pressure was maintained until delivery, but was relaxed if insertion/ventilation was difficult. Patients were intubated if an effective airway was not obtained within 90 sec, or SpO(2) <94%, or end-tidal CO(2) >45 mmHg. Postdelivery, vecuronium and fentanyl were administered.

RESULTS

An effective airway was obtained in 1060 (99%) patients, 1051 (98%) at the first attempt and nine (1%) at the second or third attempt. Air leakage or partial airway obstruction occurred in 22 (21%) patients, and seven (0.7%) patients required intubation. There were no episodes of hypoxia (SpO(2) <90%), aspiration, regurgitation, laryngospasm, bronchospasm or gastric insufflation. Surgical conditions were satisfactory and all APGAR scores were >/=7 after five minutes.

CONCLUSION

We conclude that the LMA is effective and probably safe for elective Cesarean section in healthy, selected patients when managed by experienced LMA users.

Circling mouse: possible animal model for deafness

Mutant mice with abnormalities are potentially useful as models for studying human defects. Here we report a group of mice with abnormal behavioral patterns. A new spontaneous mutant mouse exhibited hyperactive behavior at about seven days of age, followed by tight circling behavior. Breeding studies suggest that this mutation is caused by a single gene defect inherited in an autosomal recessive manner. Consequently, this mutation is referred to as a circling (cir) mouse mutation with the gene symbol cir. Auditory test results identified clearly the hearing loss of the cir, compared with wild-type mice. Pathologic studies confirmed developmental defects in cochlea and spiral ganglions that were correlated to the abnormal behavior observed in the cir mice. Thus, cir mice may be useful as a model for studying inner ear abnormalities and deafness in humans.

Simple bone cyst of lamina of lumbar spine: a case report

STUDY DESIGN

A case report and literature review.

OBJECTIVE

To describe an extremely rare simple bone cyst involving the lamina of the lumbar spine.

SUMMARY OF BACKGROUND DATA

Simple bone cysts involving the spine are very rare. Moreover, the authors are unaware of any published report of a simple bone cyst involving the lamina of the spine.

METHODS

A cystic lesion, incidentally identified in a patient with lumbar disc herniation of L5-S1, located at the left lamina of L5, was surgically treated with complete resection of the involved lamina and discectomy of L5-S1. Medical records, imaging studies, histologic findings, and related literature are reviewed in this study.

RESULTS

Histologic examination of a section of the cystic lesion showed a thin fibrous lining membrane of the cyst surrounded by well-vascularized new bone formation. This result is consistent with the findings of previously reported simple bone cysts in other sites of the body, including the spine.

CONCLUSION

This study suggests that a simple bone cyst may be included in the differential diagnosis of a cystic lesion of the posterior elements, especially laminae, of the spine.

Enantioselective binding of ofloxacin to B form DNA

The binding affinity and binding mode of S- and R-ofloxacin, one of the quinolone antibiotics, to B form calf thymus DNA were studied in this work. The binding affinity of S-ofloxacin measured by both Stern-Volmer and Benesi-Hilderbrand methods was greater by a factor of 5 compared to R-enantiomer and the CD spectrum of the former is largely altered while that of the latter remained the same in the presence of DNA, indicating the enantiospecific binding of this drug to DNA. The binding geometry of both S- and R-ofloxacin calculated from the reduced linear dichroism was similar to norfloxacin, which is partially intercalated from the minor groove.

Adenovirus-directed expression of dominant negative estrogen receptor induces apoptosis in breast cancer cells and regression of tumors in nude mice

BACKGROUND

Estrogen receptors (ER) are expressed in about two thirds of human breast cancer, and are an important pharmacological target for treatment of these tumors. Dominant negative forms of the ER have been suggested as an alternative method to disrupt ER function. In this study, we examined the effect of dominant negative ER mutants (ER1-536 and L540Q) on ER-positive breast cancer cells in vitro and in vivo.

MATERIALS AND METHODS

ER-positive T47D breast cancer cells were infected with adenoviral vectors expressing ER1-536 and L540Q to examine the effects of the mutants on gene expression and cell growth. Adenoviral vectors containing the wild type ER (AdwtER) and beta-galactosidase gene (AdGal) were used as controls.

RESULTS

Ad1-536 or AdL540Q infection inhibited T47D cell growth and induced apoptosis, increasing Bax protein and phosphorylation of p38 mitogen-activated-protein kinase (MAPK). Consistent with the apoptotic effects in vitro, pre-infection of T47D cells with Ad1-536 or AdL540Q inhibited tumor formation when these cells were introduced into nude mice. In addition, injection of Ad1-536 and AdL540Q into pre-established T47D tumors induced tumor regression. Apoptosis, in conjunction with the activation of caspase-3 and phosphorylation of p38 MAPK, was detected in the shrinking tumors. Overexpression of wild-type ER by AdwtER infection also produced antiproliferative and apoptotic effects, but to a lesser extent than the ER1-536 and L540Q mutants.

CONCLUSIONS

These results indicate that dominant negative ER mutants have the potential to induce apoptosis of T47D cells and regression of tumors. The delivery of dominant negative ERs by adenoviral vectors may provide a useful tool for targeted therapy of ER-positive breast cancer.

Brief-duration high-intensity chemotherapy for patients with small noncleaved-cell lymphoma or FAB L3 acute lymphocytic leukemia: results of cancer and leukemia group B study 9251

PURPOSE

To define the activity and feasibility of brief-duration high-intensity chemotherapy for adults with small noncleaved, non-Hodgkin's lymphoma (SNC) and the L3 variant of acute lymphocytic leukemia (L3 ALL).

PATIENTS AND METHODS

Seventy-five adults with either SNC or L3 ALL (median age, 44 years) were treated with an aggressive regimen that consisted of one cycle of cyclophosphamide and prednisone followed by cycles containing either ifosfamide or cyclophosphamide; high-dose methotrexate, vincristine, dexamethasone, and either doxorubicin or etoposide/cytarabine; or intrathecal triple therapy with prophylactic CNS irradiation.

RESULTS

All 24 patients with L3 ALL and the 30 of 51 patients with SNC confirmed by central histologic review were included in this analysis. Forty-three of 54 patients achieved complete response (CR) (18 of 24 with ALL and 25 of 30 with SNC), and 28 are alive and in continuous CR with a median follow-up of 5.1 years. Hematologic toxicity was profound, and nonhematologic toxicity was notable, with 10 of 75 patients treated developing significant neurologic toxicity consisting of transverse myelitis in five patients, CNS toxicity in three, and severe peripheral neuropathy in two. All patients who did not achieve CR died of the disease, and all recurrences occurred within 16 months of the end of treatment. Responses and toxicities were similar in the patients with both lymphoma and leukemia.

CONCLUSION

Aggressively delivered chemotherapy is potentially curative in as many as half of patients with SNC and the L3 ALL variant. This treatment regimen had considerable neurologic toxicity and has been modified.

Dietary isothiocyanates, glutathione S-transferase -M1, -T1 polymorphisms and lung cancer risk among Chinese women in Singapore

Chinese populations consume a diet relatively high in isothiocyanates (ITCs), a derivative of cruciferous vegetables known to have cancer-protective effects. This class of compounds is metabolized by the glutathione S-transferase family of enzymes, which are also involved in the detoxification of tobacco-related carcinogens such as polycyclic aromatic hydrocarbons and alkyl halides. We evaluated the association between dietary isothiocyanate intake, GSTM1 and GSTT1 polymorphisms, and lung cancer risk in 420 Chinese women: 233 histologically confirmed lung cancer patients and 187 hospital controls. Among these, 58.8% of cases and 90.3% of controls were lifetime nonsmokers. An allele-specific PCR method was used to detect the presence or absence of the GSTM1 and GSTT1 genes in DNA isolated from peripheral blood. Higher weekly intake of ITCs (above the control median value of 53.0 micromol) reduced the risk of lung cancer to a greater extent in smokers [adjusted odds ratio (OR), 0.31; 95% confidence interval (CI), 0.10-0.98] than nonsmokers (OR, 0.70; 95% CI, 0.45-1.11). The inverse association was stronger among subjects with homozygous deletion of GSTM1 and/or GSTT1. Among nonsmokers with GSTM1-null genotype, higher intake of ITCs significantly reduced the risk of lung cancer (OR, 0.54; 95% CI, 0.30-0.95), an effect not seen among those with detectable GSTM1 (OR, 1.07; 95% CI, 0.50-2.29). Our results, in a Chinese female population, are consistent with the hypothesis that ITC is inversely related to the risk of lung cancer, and we show that among nonsmokers this effect may be primarily confined to GST-null individuals. Conjugation and elimination of ITCs is enhanced in GST-non-null relative to -null individuals, such that the GST metabolic genotype modifies the protective effect of ITCs on lung cancer development.

The value of cystoscopy and intravenous urography after magnetic resonance imaging or computed tomography in the staging of cervical carcinoma

The clinical staging system for cervical carcinoma presently recommended by the International Federation of Gynecology and Obstetrics (FIGO) does not include MRI or CT findings and thus suffers limited accuracy. Recently however, the positive contributions of MRI and CT to preoperative staging have been reported. This study involves a determination of the value of routine cystoscopy and intravenous urography, in the detection of bladder invasion or hydronephrosis resulting from cervical carcinoma, among patients who had undergone MRI or CT. Among a total 296 patients with cervical carcinoma, 271 patients (92%) had undergone MRI and 25 (8%) CT. Bladder invasion was identified pathologically by cystoscopic biopsy in 8 (57%) of the 14 patients with suspected bladder invasion on MRI or CT. There was no bladder invasion in any of the other cases lacking in bladder invasion evidence on MRI or CT. Hydronephrosis was identified by intravenous urography in 18 patients, as it also was in all of these cases on MRI or CT, confirming a negative predictive value for MRI or CT, in detecting bladder invasion or hydronephrosis from cervical carcinoma, of 100%. Therefore, although MRI or CT cannot totally replace cystoscopy, the latter is unnecessary in the absence of bladder invasion evidence on MRI or CT. Intravenous urography, however, can be safely omitted whenever MRI or CT is performed.

SigB, an RNA polymerase sigma factor required for osmoprotection and proper differentiation of Streptomyces coelicolor

A gene (sigB) encoding an alternative sigma factor sigmaB in Streptomyces coelicolor A3(2) was isolated and characterized. It encodes a polypeptide of 281 amino acids (31 546 Da) and is highly homologous to Bacillus subtilis sigmaB. The sigB coding region is preceded by four open reading frames (ORFs): dpsA, orfA, rsbB and rsbA in sequential order. RNA analyses revealed that rsbB, rsbA and sigB constitute an operon (sigB operon). Transcripts were produced constitutively from a promoter (sigBp2) upstream of the rsbB coding region, contributing to the basal level expression of sigmaB protein. An inducible promoter (sigBp1) resembling the catB promoter (catBp) was located between the rsbA and sigB coding regions. Transcripts from sigBp1 dramatically increased as cells differentiated on solid media, at the stationary phase in liquid media or by osmotic stresses similar to the behaviour of catBp transcripts. Both catBp and sigBp1 promoters were recognized specifically by sigmaB-containing RNA polymerase in vitro. Disruption of the sigB gene abolished not only the differentiation-associated expression but also the osmotic induction of the catB gene, indicating that catBp is under the control of sigmaB. The sigB mutant exhibited a similar phenotype to the catB mutant, being sensitive to hyperosmolarity, blocked in forming aerial mycelium and with skewed antibiotic production. Therefore, we conclude that sigmaB ensures the proper differentiation and osmoprotection of S. coelicolor cells, primarily via regulation of the expression of catalase B.

Iodide-to-cation charge-transfer bands as a novel probe for evaluation of actual acceptor strengths of cations in zeolites and cation-dependent pore volume change

Iodide-to-cation charge-transfer (ITC-CT) bands have been measured for the first time in zeolites X and Y exchanged with a series of alkali metal ions and the results show that the ITC-CT band progressively red shifts with increasing the size and the number of site III cations in the supercage, which indicates that the actual acceptor strength of the cation toward iodide increases with increasing the degree of protrusion of the cation into supercages and the number of cations, and overall, with decrease in supercage volume.

Marked anemic hypoxia deteriorates cerebral hemodynamics and brain metabolism during massive intracerebral hemorrhage

The present study was undertaken to investigate the influence of imposed anemic hypoxia on cerebral hemodynamics and metabolism in a condition of massive ICH. Two groups of eight dogs, with a target hemoglobin concentration of 12 g/dl in nonanemic and 6 g/dl in anemic group, were included. Before the onset of the insult, anemic group had a significant reduction (p<0.05) in cerebral arteriovenous oxygen content difference (AVDO2), accompanied with a significant rise (p<0.05) in flow velocity (FV) of the basilar artery and cerebral extraction fraction of oxygen (CEO2) and a lower brain-tissue lactate clearance than did nonanemic group. Shortly after ICH, both groups displayed significant reductions (p<0.05) in FV, CEO2 and AVDO2, and simultaneous rises in arteriovenous lactate concentrations. In nonanemic group, the CEO2 and AVDO2 gradually returned after an initial decrease, and then the arteriovenous lactate concentrations slowly decreased. In contrast, anemic group showed progressive reductions in CEO2 and AVDO2 associated with persistent rises in arteriovenous lactate concentrations. Consequently, anemic group exhibited significantly greater brain-tissue lactate clearances (p<0.05), occurring at 10 min and 5 h postinjury, than did nonanemic group, although the former had relatively higher levels of CEO2 up to 3 h postinjury. We conclude that anemic hypoxia modulates a favorable change in cerebral hemodynamics and oxygenation, while it progressively deteriorates after an initial reduction during massive ICH, thus facilitating cerebral anaerobic glycolysis in biphasic periods. These results point to a complex interaction between cerebral hemodynamics, oxygen supply and glycolysis homeostasis upon the addition of anemic hypoxia in severe stress conditions of the brain.

Dominant negative ER induces apoptosis in GH(4) pituitary lactotrope cells and inhibits tumor growth in nude mice

The ER plays an important role in the proliferation and differentiation of lactotrope tumor cells. GH(4) cells were infected with adenoviral vectors (AdL540Q and Ad1-536) to investigate the ability of dominant negative ER mutants to affect the regulation of gene expression and cell growth by endogenous ER. The dominant negative mutants suppressed estradiol stimulation of an estrogen-responsive reporter gene and the PRL promoter in these cells. AdL540Q or Ad1--536 infection also inhibited GH(4) cell growth and induced apoptosis, increasing the expression of the proapoptotic Bax protein and decreasing the expression of antiapoptotic Bcl-2. AdwtER-infected cells also showed decreased Bcl-2 protein. E2-induced activation of p38 MAPK, an enzyme that may participate in apoptosis, was observed in cells infected with AdwtER, AdL540Q, and Ad1--536. Consistent with the apoptotic effects in vitro, infection of GH(4) cells with AdL540Q or Ad1--536 inhibited the ability of the cells to form tumors in nude mice. These results indicate that dominant negative ER mutants induce apoptosis of GH(4) cells and suppress tumor formation and development. The delivery of dominant negative ERs by adenoviral vectors may provide an alternative modality for the targeted therapy of pituitary lactotrope adenomas and other estrogen-responsive tumors.

Absence of constitutively activating mutations in the GHRH receptor in GH-producing pituitary tumors

The molecular events leading to the development of GH-producing pituitary tumors remain largely unknown. We hypothesized that activating mutations of the GHRH receptor might occur in a subset of GH-producing pituitary tumors. Genomic DNA samples from 54 GH-producing pituitary tumor tissues were screened for mutations of the GHRH receptor. Eleven homozygous or heterozygous nucleotide substitutions [169G > A (A57T), 338C > T (P113L), 363G > T (E121D), 409C > T (H137Y), 547G > A (D183N), 673G > A (V225I), 749G > A (W250X), 760G > A (V254M), 785G > A (S262N), 880G > A (G294R), 1268G > A (C423Y)] were found in 12 patients (22.2%). The 169G > A substitution (A57T) appears to be a polymorphism (4 patients, 7.4%). E121D and V225I were each found in 2 patients. In 1 patient with the V225I sequence, the substitution was not found in genomic DNA from peripheral leukocytes, suggesting a somatic mutation. A patient with a heterozygous W250X mutation was homozygous for the C423Y substitution. These variant GHRH receptors were studied in transfected TSA-201 cells to evaluate the functional consequences of the amino acid changes. None of the GHRH receptor variants was associated with basal elevation of intracellular cAMP. GHRH induced variable cAMP responses. With the W250X and G294R variants, there was no cAMP stimulation by GHRH, indicating that the mutations are inactivating. Expression of the W250X GHRH receptor on the cell membrane was severely decreased and GHRH binding to the G294R GHRH receptor was impaired. Although GHRH receptor variants are common in GH- producing pituitary adenomas, constitutively activating mutations, as a mechanism for GH-producing pituitary tumors appear to be rare.

Genetic heterogeneity in Korean families with autosomal-dominant polycystic kidney disease (ADPKD): the first Asian report

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disease in adults, and the prevalence of this disease within the chronic haemodialysis patient population is known to be approximately 2% in Korea. So far, three genetic locus have been identified as being responsible for ADPKD, and approximately 85% of the cases in Western countries are related to the PKD1 gene. However, little information is available concerning the pattern of linkage analysis in Asian populations.

METHODS

48 families with hereditary renal cysts were recruited by consent and their molecular genetic characteristics were studied. Linkage analysis was done with microsatellite markers (PKD1: SM7, UT581, AC2.5, KG8, D16S418; PKD2: D4S423, D4S1534, D4S1542, D4S1544, D4S2460). Genomic DNA polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis (PAGE) gel run were performed, and the resultant allele patterns were compared with sonographic findings.

RESULTS

The results of this study showed that the ratio PKD1:PKD2 was 31:8, and that the PKD2 families exhibited a tendency toward a milder renal prognosis than the PKD1 families.

CONCLUSION

We confirmed the applicability of linkage analysis for ADPKD in the Korean population, and our data confirmed a similar incidence of PKD1 (79%) and PKD2 (21%) in Korean patients as in the Western population.

Postremission therapy in older patients with de novo acute myeloid leukemia: a randomized trial comparing mitoxantrone and intermediate-dose cytarabine with standard-dose cytarabine

The treatment of older patients with acute myeloid leukemia (AML) remains unsatisfactory, with complete remission (CR) achieved in only approximately 50% and long-term disease-free survival in 10% to 20%. Three hundred eighty-eight patients (60 years of age and older) with newly diagnosed de novo AML were randomly assigned to receive placebo (P) or granulocyte-macrophage colony-stimulating factor (GM-CSF) or GM in a double-blind manner, beginning 1 day after the completion of 3 days of daunorubicin and 7 days of cytarabine therapy. No differences were found in the rates of leukemic regrowth, CR, or infectious complications in either arm. Of 205 patients who achieved CR, 169 were medically well and were randomized to receive cytarabine alone or a combination of cytarabine and mitoxantrone. With a median follow-up of 7.7 years, the median disease-free survival times were 11 months and 10 months for those randomized to cytarabine or cytarabine/mitoxantrone, respectively. Rates of relapse, excluding deaths in CR, were 77% for cytarabine and 82% for cytarabine/mitoxantrone. Induction randomization had no effect on leukemic relapse rate or remission duration in either postremission arm. Because cytarabine/mitoxantrone was more toxic and no more effective than cytarabine, it was concluded that this higher-dose therapy had no benefit in the postremission management of older patients with de novo AML. These results suggest the need to develop novel therapeutic strategies for these patients. (Blood. 2001;98:548-553)

Solvent effect on the alpha-effect for the reactions of aryl acetates with butane-2,3-dione monoximate and p-chlorophenoxide in MeCN-H2O mixtures

Second-order rate constants have been measured spectrophotometrically for the nucleophilic reactions of three substituted phenyl acetates with butane-2,3-dione monoximate (Ox(-)) as an alpha-nucleophile and p-chlorophenoxide (ClPhO(-)) as corresponding normal nucleophile, in MeCN-H2O mixtures of varying compositions at 25.0 +/- 0.1 degrees C. The reactivity of Ox(-) toward the aryl acetates decreases upon addition of MeCN to the reaction medium up to ca. 30 mol % MeCN, followed by a gradual increase in rate upon further addition of MeCN. A similar result has been obtained for the reaction of ClPhO(-) with the aryl acetates. However, the decrease in rate is more significant for the less reactive ClPhO(-) than for the more reactive Ox(-). Thus, for all the aryl acetates studied, Ox(-) exhibits a sizable alpha-effect (k(Ox)-/k(ClPhO)-) whose magnitude increases as the mol % MeCN in the reaction medium increases. The relative basicities (DeltapK(a)) of Ox(-) and ClPhO(-) have been determined spectrophotometrically using piperazine as a reference base. The DeltapK(a) values increase on increasing the mol % MeCN in the medium for both Ox(-) and ClPhO(-). The difference in the relative basicities of these nucleophiles (DeltaDeltapK(a)) becomes larger with increasing mol % MeCN. The plots of log k(Ox)-/k(ClPhO)- vs DeltaDeltapK(a) for the three substrates are linear with near-unit slope, indicating that the difference in the relative basicity of the nucleophiles is largely responsible for the increasing alpha-effect with medium composition in this system.

Electron spin resonance studies of free radicals in gamma-irradiated soybean paste

Free radicals in gamma-irradiated soybean paste were investigated by electron spin resonance (ESR) spectroscopy to determine the effect of temperature (77-296 K) and moisture content (1-54%) of samples irradiated at high dose (1-40 kGy). The samples were kept in liquid nitrogen (77 K) during irradiation and subsequent ESR measurements. The spectra shown at 77 K consisted of the hydrogen atom lines at low and high field and complicated symmetric spectrum. By increasing the microwave power, the line shape of ESR spectra altered, which indicated the detection of different paramagnetic centers at different microwave powers. In saturation curves, it was possible to select four types of spectra components which were different in their relaxation times. By the different irradiation doses, the change in free radical concentration showed a curvilinearly increasing relationship with irradiation dose in wet samples, whereas a proportional relationship was observed with dried samples. This might indicate that the indirect process of free radical formation was involved with the existence of free water radicals in the wet samples.

Effect of bradykinin on cultured bovine corneal endothelial cells

PURPOSE

To clarify the effect of bradykinin on cytosolic free calcium mobilization and cell proliferation in cultured bovine corneal endothelial cells (BCEC).

METHODS

The cytosolic free calcium concentration (Ca2+]i) was measured with the InCa(TM) Imaging System after the treatment of bradykinin (10(-11) to 10(-7) M) alone or with the pretreatments of EGTA, bradykinin receptor (Bk1 and Bk2) antagonists and an inhibition of phospholipase C (U-73122). Also, the effect of bradykinin on cell proliferation in BCEC was evaluated using cell counts.

RESULTS

In BCEC, [Ca2+]i in the resting state was 87 +/- 9 nM. Bradykinin induced an increment of [Ca2+]i in a concentration-dependent manner and its 50% effective concentration was approximately 5 x 10(-11) M. A [Ca2+]i increment at 10(-8) M bradykinin was inhibited with the pretreatment of EGTA, an extracellular calcium chelator. U-73122 (5 x 10(-6) M) attenuated the bradykinin-induced [Ca2+]i increment. The pretreatment of HOE-140 (Bk2 antagonist) almost attenuated the bradykinin (10(-8) M)-induced [Ca2+]i increase, but des-Arg9-[Leu(8)]-bradykinin (Bk1 antagonist) did not suppress it. To investigate the physiological effect of bradykinin, the effect of bradykinin on cell proliferation was studied. 10(-8) M of bradykinin produced a significant increase in cell numbers. This mitogenic effect of bradykinin was inhibited by the Bk2 antagonist.

CONCLUSIONS

Bradykinin-induced stimulation of the signal transduction pathway in BCEC is coupled with the Bk2 type receptor. Furthermore, bradykinin produces the mitogenic effect in BCEC.

Innervation of the lower eyelid in relation to blepharoplasty and midface lift: clinical observation and cadaveric study

Ectropion or scleral show resulting from weakness of the lower eyelids is not uncommon after lower blepharoplasty or midface lift via blepharoplasty incision. Denervation of the pretarsal orbicularis oculi muscle (OOM) attributes to such complications. The authors analyzed 102 patients who underwent midface lift via lower blepharoplasty incision for the past 3 years and investigated the motor nerve innervation of the lower OOM in 20 cadavers. They encountered two cases of ectropion attributed to the denervation of the pretarsal OOM: one with dry-eye syndrome and scleral show, and the other with a "polar bear-like appearance" (i.e., outer eversion of the lower eyelid). All pretarsal and preseptal OOMs were innervated by five to seven terminal twigs of the zygomatic branches of the facial nerve that approached the muscle at a right angle. The medial portion of the lower OOM was innervated by one to two terminal twigs of the buccal branch, and the middle portion was innervated with two to three twigs of the zygomatic branch. The lateral portion was supplied by the uppermost zygomatic branch, which split into two to four twigs. The mean horizontal distance between the lateral canthus and the zygomatic branch was 2.31 +/- 0.29 cm (range, 1.7-2.7 cm) and the vertical distance was 1.20 +/- 0.20 cm (range, 0.8-1.5 cm). The critical zone was a circle with 0.5-cm radius, and its center was located 2.5 cm inferolaterally (30 deg) from the lateral canthus. It is very important to understand the motor nerve innervation of the lower eyelid and the "critical zone" to avoid postoperative ectropion or weakness of the lower eyelid resulting from paralysis of the pretarsal or preseptal OOM.

Adenovirus-mediated targeted expression of toxic genes to adrenocorticotropin-producing pituitary tumors using the proopiomelanocortin promoter

Management of Cushing's disease remains challenging, despite advances in its diagnosis and treatment. Here, we describe a strategy for targeting the expression of toxic genes to ACTH-producing tumor cells using adenoviral vectors. The POMC promoter was used to express either a marker gene (beta-galactosidase) or a toxic gene [herpes simplex virus thymidine kinase (TK)]. In ACTH-producing AtT20 cells, infection with recombinant adenoviruses containing the POMC promoter (AdPOMCGal; AdPOMCTK) led to high-level gene expression. Stereotactic injection of AdPOMCGal into the rat pituitary resulted in localized expression of the beta-galactosidase transgene in corticotrope cells. Cytotoxicity studies were performed using the TK-containing vectors and treatment with ganciclovir. AdPOMCTK caused greater than 95% cytotoxicity of AtT20 cells at a viral dose (multiplicity of infection, 5 plaque-forming units/cell) that induced minimal toxicity using control viruses. No cellular toxicity was seen using a nonpituitary cell line (T47D breast tumor cells). AtT20 cells transplanted into nude mice induced features of Cushing's syndrome and were used as an in vivo model of ACTH-producing tumors. Injection of the AdPOMCTK virus caused significant regression of the transplanted AtT20 tumors. These studies suggest that the POMC promoter may provide a useful gene therapy strategy for the adjunctive treatment of pituitary tumors causing ACTH-dependent Cushing's syndrome.

The expression and cellular localization of phospholipase D1 in the rodent retina

Phospholipase D (PLD) is one of the intracellular signal transduction enzymes and plays an important role in a variety of cellular functions. We investigated the expression and cellular localization of the PLD isozyme PLD1 in the rodent retina. Western blot analysis showed the presence of PLD1 at the protein level in the rat, mouse and guinea pig retinas. PLD1 immunoreactivity was localized in all Müller cells. Thus, PLD1 protein appears to be important in the functions of these cells in the rodent retina.

Inherited disorders of the gonadotropin hormones

Pulsatile GnRH acts at the GnRH receptor on gonadotropes to stimulate gonadotropin gene expression, hormone synthesis and secretion. The pituitary gonadotropins, LH and FSH, stimulate steroid production and gametogenesis in males and in females. Gonadotropin production thus requires the normal development and function of hypothalamic GnRH-producing neurons and pituitary gonadotrope cells. Genes involved in gonadotrope development and/or gene expression include SF1, DAX1, KAL, GNRHR, PC1, HESX1, LHX3, PROP1, LH beta, and FSH beta. Given the complex control of gonadotropin biosynthesis and secretion, it is not surprising that genetic abnormalities have been identified at several of these steps. Some of the mutations that will be reviewed include: (1) SF1 and DAX1-orphan nuclear receptors that are expressed at multiple levels throughout the reproductive axis; (2) KAL-X-linked Kallmann syndrome, where there is abnormal development of hypothalamic GnRH-producing neurons; (3) PC1-causing abnormal processing of GnRH and GNRHR mutations that impair action at the GnRH receptor; (4) HESX1, LHX3, PROP1-abnormal development/function of the gonadotrope cell lineage; (5) LH beta and FSH beta-mutations in the gonadotropin genes that cause structural abnormalities in the hormones. Although all of these gene defects lead to gonadotropin deficiency, each disorder is associated with unique phenotypic or hormonal features. Characterization of the molecular basis of gonadotropin deficiency is useful for directing therapy and for genetic counseling. Identification of these mutations also provides insight into the pathways that govern reproduction.

Antiallergic action of Magnolia officinalis on immediate hypersensitivity reaction

We studied the effect of aqueous extract of Magnolia officinalis bark (Magnoliaceae) (MOAE) on the immediate hypersensitivity reaction. MOAE (0.01 to 1 g/kg) dose-dependently inhibited compound 48/80 induced systemic anaphylaxis in rats. MOAE (0.1 and 1 g/kg) also significantly inhibited local immunoglobulin E (IgE)-mediated passive cutaneous anaphylactic reaction. When MOAE was pretreated at concentrations ranging from 0.01 to 1 g/kg, the levels of plasma histamine were reduced in a dose-dependent manner. MOAE (0.001 to 1 mg/ml) dose-dependently inhibited the histamine release from rat peritoneal mast cells (RPMC) activated by compound 48/80 or anti-dinitrophenyl (DNP) IgE. The level of cyclic AMP (cAMP) in RPMC, when MOAE was added, significantly increased compared with that of the normal control. Moreover, MOAE (0.01 to 1 mg/ml) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production from RPMC. These results indicate that MOAE inhibits immediate hypersensitivity reaction in vivo and in vitro.

Bioavailability of cyclosporin A dispersed in sodium lauryl sulfate-dextrin based solid microspheres

The purpose of this work was to develop a solid dispersion system containing cyclosporin A (CsA) in order to improve the bioavailability of poorly water-soluble CsA. Solid dispersion systems that are spherical in shape (CsA-microspheres) were prepared with varying ratios of CsA/sodium lauryl sulfate/dextrin using a spray-drying technique. The effects of sodium lauryl sulfate (SLS) and dextrin on the dissolution of CsA dispersed in SLS-dextrin based solid microspheres were investigated. The bioavailability of CsA-microspheres was compared with CsA powder alone and commercial Sandimmun in dogs. SLS significantly enhanced the dissolution of CsA from microspheres, while dextrin did not affect this. The CsA-microspheres at the CsA/SLS/dextrin ratio of 1/3/1, which gave the highest dissolution rate of CsA among the formula treated, was selected as an optimal formula for oral delivery. This formula gave significantly higher blood levels, area under the drug concentration-time curve (AUC) and maximum blood concentration of drug (Cmax) of CsA in dogs compared with the CsA powder alone. The AUC, Cmax and time to reach maximum blood concentration (Tmax) of CsA with CsA-microspheres was not significantly different from those after oral administration of Sandimmun, suggesting the similar bioavailability to Sandimmun in dogs. Our study demonstrates that the CsA-microspheres prepared with SLS and dextrin, with improved bioavailability of CsA, would be useful to deliver a poorly water-soluble CsA and could be applicable to other poorly water-soluble drugs.

Subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, after single and 4-week repeated oral administration in dogs

The subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, were evaluated after single (at the 1st day) and 4-week (at the 28th day) oral administration of the drug, in doses of 0 (to serve as a control), 12.5, 50 and 200 mg/kg/day, to male and female dogs (n=3 for male and female dogs for each dose). DA-8159 had an effect on the immune-related organs (or tissues), circulatory systems, liver, adrenal glands, ovaries and pancreas. The toxic dose was 200 mg/kg and no observed adverse effect level was less than 50 mg/kg for male and female dogs. There were no significant gender differences in the pharmacokinetic parameters of DA-8159 for each dose after both single and 4-week oral administration. The pharmacokinetic parameters of DA-8159 were dose-independent after single oral administration; the time to reach a peak plasma concentration (T(max)) and the dose-normalized area under the plasma concentration-time curve from time zero to 24 h in plasma (AUC(0-24 h)) were not significantly different among three doses. However, accumulation of DA-8159 after 4-week oral administration was considerable at toxic dose, 200 mg/kg/day. For example, after 4-week administration, the dose-normalized AUC(0-24 h) value at 200 mg/kg/day (4.71 and 15.3 microg h/ml) was significantly greater than that at 12.5 mg/kg/day. After 4-week oral administration, the dose-normalized C(max) and AUC(0-24 h) at 200 mg/kg/day were significantly higher and greater, respectively, than those after a single oral administration.

Cytochrome P4501A2 (CYP1A2) activity and lung cancer risk: a preliminary study among Chinese women in Singapore

There is increasing evidence for the role of heterocyclic and other arylamines in carcinogenesis, including lung carcinogenesis. Chinese women have a high rate of lung cancer despite a low smoking prevalence, and studies in this population may provide useful information on risk factors other than smoking. Hepatic CYP1A2 and NAT2 are involved in the metabolism of carcinogenic arylamines, and NAT2 also catalyzes the detoxification pathway for these compounds. In this study, we examined the effect of CYP1A2 activity using a urinary caffeine metabolic ratio assay for 54 Chinese women with newly diagnosed lung cancer (including 28 adenocarcinomas) and 174 hospital controls. Among them, NAT2 genotype was available for 47 cases and 98 controls. There was no effect of CYP1A2 activity on overall risk of lung cancer in the study population [odds ratio (OR) 0.8, 95% confidence interval (CI) 0.4-1.6, adjusted for age at diagnosis, smoking and cruciferous vegetable intake]. For adenocarcinomas, the OR was 1.5, 95% CI 0.6-3.4. After further adjustment for NAT2 acetylator genotype, the OR for adenocarcinoma was 1.8 (95% CI 0.7-4.8). When the combined NAT2/CYP1A2 status was examined, women with slow NAT2 and rapid CYP1A2 activity were at highest risk (adjusted OR 6.9, 95% CI 1.3-37.6) relative to women with rapid NAT2 and slow CYP1A2 activity, for lung adenocarcinoma. While larger studies are needed to confirm or refute these results, they are consistent with a role for heterocyclic arylamines in lung carcinogenesis in this primarily non-smoking population.

Morphological analysis of CD15-immunoreactive neurons in the guinea pig retina

Using immunocytochemistry, morphometry and electron microscopy, we have investigated the distribution and characteristics of CD15-immunoreactive (IR) neurons in the guinea pig retina. In the present study, two types of amacrine cells, including interplexiform cells in the inner nuclear layer (INL) and some cells in the ganglion cell layer (GCL), were labeled with anti-CD15 antisera. Type 1 amacrine cells had large somata located in the INL, with long and branched processes ramifying mainly in strata 4 and 5 of the inner plexiform layer (IPL). Somata of type 2 cells had smaller diameters, and were also located in the INL. Their processes stratified in stratum 1. The densities of type I and type 2 amacrine cells increased from 152.8+/-36.7/mm2 and 160.6+/-61.7/mm2 in the peripheral retina, to 404.3+/-41.5/mm2 and 552.2+/-72.2/mm2 in the central retina, respectively. Cells in the GCL exhibiting CD15 immunoreactivity were rarely observed. Colocalization experiments, using consecutive semi-thin sections, demonstrated that these CD15-IR amacrine cells exhibited gamma-aminobutyric acid (GABA) immunoreactivity. In addition, the processes of the type 1 cells formed one member of the postsynaptic dyads that are formed in the axon terminals of rod bipolar cells. Most of these processes made reciprocal synapses back to the axon terminals of the rod bipolar cells. Thus, CD15-IR amacrine cells constitute a subpopulation of GABAergic amacrine cells in the guinea pig retina, and the type 1 cells among them provide the inhibitory input to rod bipolar cells.