Fluorescence quenching properties and chemiluminescence responses of alpha-ketothiols derivatized with o-phthalaldehyde and primary amino compounds

Fluorescence and chemiluminescence responses of thiols derivatized with o-phthalaldehyde (OPA) and primary amines have been studied. Among thiols tested, those having an alpha-ketothiol structure [R-CH(SH)-CO-] were found to give extremely low fluorescence intensities when derivatized with OPA and L-valine. The relative fluorescence intensities of alpha-ketothiols, such as mercaptoacetic acid (MAA), 2-mercaptopropionic acid (2-MPA), mercaptosuccinic acid (MSA) and N-(2-mercaptopropionyl)glycine (MPG), were only below 3% of that of N-acetyl-L-cysteine (NAC), having no alpha-ketothiol structure. The addition of detergents such as sodium dodecylsulphate had no effect on the fluorescence and an aprotic solvent (dimethylsulphoxide) showed little effect, whereas these thiols chemiluminesced intensely when derivatized with OPA and N-(4-aminobutyl)-N-ethylisoluminol as a primary amine and successively detected by high-performance liquid chromatography (HPLC) with postcolumn chemiluminescence reactions using hydrogen peroxide and haematin. The relative chemiluminescence intensities of MSA, 2-MPA and MPG to NAC were 41.0%, 27.8% and 117%, respectively. MPG was estimated to be detectable at a concentration level of at least 10 fmol per injection. In conclusion, the weak fluorescence of the alpha-ketothiols derivatized with OPA and primary amines is probably due to the low fluorescence quantum yields of the derivatives, and HPLC with a chemiluminescence detection system is useful for the sensitive detection of thiols.

Electrical activity of the pulse generator of gonadotropin-releasing hormone in 26-month-old female rats

To know whether age-related changes occur in the activity of the pulse generator of gonadotropin-releasing hormone (GnRH), old (26 months) and young (3 months) female rats were examined by recording multiunit activity (MUA) in the median eminence region of the hypothalamus, concurrently with blood samplings through an intra-atrial cannula at 6-min intervals to determine serum luteinizing hormone (LH) concentrations. We have regarded the MUA showing intermittent increases (volleys) at 20-30 min intervals, followed by LH pulses, as the electrical activity of the GnRH pulse generator. We were successful in recording MUA in 18 (26%) of 69 old ovariectomized rats and in 8 (32%) of 25 young ovariectomized rats. The overall mean (+/-SE) of the interval between MUA volleys in old ovariectomized rats was 35.1 +/- 2.0 min (n = 18), which was significantly longer than that of 22.5 +/- 1.5 min (n = 8) in young ovariectomized rats. The mean interval between LH pulses in old ovariectomized rats was 32.2 +/- 3.6 (n = 10), also being significantly longer than that of 23.3 +/- 1.0 (n = 8) in young ovariectomized rats. Further, the LH pulse amplitude in old rats (0. 95 +/- 0.07 ng/ml) was significantly smaller than in young rats (3. 40 +/- 0.36 ng/ml). The present study also confirmed that the increase in serum LH after intravenous injection of 50 ng GnRH was much smaller in old ovariectomized rats. These results show that the electrical activity of the GnRH pulse generator is certainly reduced with age. Taken together with findings suggesting an age-dependent decrease in stimulated transmitter release, attenuation in both frequency and amplitude of GnRH pulses as well as in pituitary responsiveness to GnRH pulses may account for the decreased pulsatile LH secretion observed in aging rats.

Diffuse intrahepatic recurrence after resection of hepatocellular carcinoma

BACKGROUND/AIMS

An early diffuse type in the pattern of the postoperative intrahepatic recurrence of hepatocellular carcinoma has been recognized. The purpose of this study was to elucidate risk factors for diffuse recurrence of hepatocellular carcinoma.

METHODOLOGY

The subjects involved in the present study were 114 patients with hepatocellular carcinomas resected in Tenri Hospital during the past 12 years. Univariate analysis was used for retrospective determination of the factors related to diffuse recurrences after surgery in 10 cases among 114 patients.

RESULTS

The risk factors linked to diffuse recurrence were microscopical portal infiltration (P < 0.01), elevated alpha-fetoprotein (more than 1000 ng/mL) (P < 0.05), the absence of preoperative transcatheter arterial embolization (P < 0.01), and two or more segmentectomies of the liver (P < 0.01). Six of 10 patients with microscopical portal infiltration and elevated alpha-fetoprotein (more than 1000 ng/mL) had diffuse recurrence (P < 0.01). Six of 8 patients with two or more segmentectomies without preoperative TAE had diffuse recurrence (P < 0.01).

CONCLUSIONS

When patients with the diagnosis of operable hepatocellular carcinoma have portal infiltration and elevated alpha-fetoprotein (more than 1000 ng/mL), two or more segmentectomies of the liver without preoperative transcatheter arterial embolization should be avoided.

Controlled local application of basic fibroblast growth factor (FGF-2) accelerates the healing of GBR. An experimental study in beagle dogs

This animal study was performed to ascertain whether the regeneration of membrane-protected bone defects can be accelerated by the controlled application of basic fibroblast growth factor (FGF-2) using a new drug delivery system. Standardized alveolar bone defects were made surgically in 9 beagle dogs, and FGF-2 was administered using specially made collagen minipellets. A minipellet containing either 0.15 microgram FGF-2 (FGF) or 0 microgram FGF-2 (placebo) was placed in the defect or no minipellet was used (control), and bone regeneration was evaluated radiologically, histologically, and histometrically 8 weeks after the operation. Radiographs showed a surprisingly large radiopaque region in FGF sites compared with placebo or control sites. Histologically, mature bone filled the majority of the inner space of the membrane-protected defect in FGF sites. New bone formation was also seen in the control and the placebo sites, however, it filled less than half the area of the defect. Histometrically, the area of regenerated bone in FGF sites was significantly higher than in the other sites (P < 0.01). These results demonstrate that the controlled application of FGF-2 accelerates bone regeneration in membrane-protected bone defects in the canine model.

A new PCR primer for the identification of Paracoccidioides brasiliensis based on rRNA sequences coding the internal transcribed spacers (ITS) and 5 x 8S regions

Internal transcribed spacer (ITS) genes including the 5.8S ribosomal (r)RNA of Paracoccidioides brasiliensis were amplified and the DNA sequences were determined. Based on a comparison of the sequence information, a new polymerase chain reaction (PCR) primer pair was designed for specific amplification of DNA for P. brasiliensis. This primer pair amplified a 418-bp DNA sequence and was 100% successful in identifying 29 strains of P. brasiliensis (including the reference strains) isolated from the regions of Brazil, Costa Rica, Japan, Argentina or from different sources. The results of specificity tests of these primers to compare the fungus with those of Aspergillus fumigatus, Blastomyces dermatitidis, Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum and Penicillium marneffei are also reported.

A surrogate method for assessment of beta(2)-integrin-dependent adhesion of human eosinophils to ICAM-1

We have developed and validated an inexpensive and equivalent method for measuring eosinophil adhesion by beta(2)-integrin to endothelial ICAM-1 using bovine serum albumin (BSA) as a surrogate for the immunoglobulin supergene. The number of adherent eosinophils on BSA or ICAM-1 coated microplates was quantified by residual eosinophil peroxidase activity. Non-stimulated eosinophils did not adhere to either BSA or ICAM-1. However, after IL-5 stimulation, either BSA or ICAM-1 caused comparable and concentration-dependent adhesion of eosinophils. Eosinophil adhesion was rapid and occurred within 15 to 30 min of incubation for either BSA or ICAM-1. Preincubation of cells with CD11b or CD18 antibody specifically decreased adhesion to either BSA or ICAM-1. IL-5, PAF and fMLP all induced adhesion of eosinophils to either BSA or ICAM-1 in a concentration-dependent manner, and the optimal IL-5, fMLP and PAF concentrations for adhesion to BSA were the same as for adhesion to ICAM-1. BSA-binding was specific for beta(2)-integrin; neither alpha-CD49d mAb directed against the alpha(4)-chain or alpha-CD29 directed against the common beta(1)-chain of VLA-4 blocked adhesion to BSA or ICAM-1 controls. The protein tyrosine kinase inhibitor, genistein, the phosphatidylinositol 3-kinase (PI-3 kinase) inhibitor, wortmanin, and mitogen-activated protein kinase kinase (MEK) inhibitor, U0126, all inhibited IL-5-induced eosinophil adhesion to either BSA or ICAM-1 comparably. These results indicate that BSA is a reliable and economical surrogate ligand for ICAM-1 adhesion to beta(2)-integrin-dependent adhesion to ICAM-1. Ligation characteristics of BSA are identical to those for soluble ICAM-1, and the assay is suitable for assessment of signal transduction pathways mediating adhesion.

[Pulmonary dirofilariasis with cavity formation and pleural effusion]

A 61-year-old man visited a community hospital because of hemosputum. A solitary nodule in the left lower lung field was pointed out on a chest roentgenogram. The patient was treated with antibiotics, but the solitary nodule increased in size. He was referred to our hospital because of high fever and observations of cavity formation and pleural effusion on a chest roentgenogram. The pleural effusion showed no cytologic evidence of malignancy, and cultures were also negative for bacteria. An increased percentage of lymphocytes was detected in the pleural effusion, but slight eosinophilia was found in blood samples. Dot enzyme-linked immunosorbent assay and Ouchterlony's double-diffusion test yielded a diagnosis of pulmonary dirofilariasis. After drainage of the pleural effusion by thoracentesis, spontaneous regression was observed. Cavity formation, pleural effusion, and spontaneous regression are in general rare in patients with pulmonary dirofilariasis.

Development of new drug delivery system for protein drugs using silicone (I)

A novel technique, by which protein drugs effective in small doses can be released over a long period, was developed using silicone and a water-soluble substance. In this study, interferon (IFN) was used as a model of the protein drugs. The IFN-silicone formulation released IFN over long periods of time in vitro and suppressed tumor growth in nude mice for about 100 days after a single administration. This indicates that physiologically active IFN is released over a prolonged period of time from the IFN-silicone formulation in vivo. Silicone formulations are expected to be a practically feasible sustained-release formulation.

Pentobarbital stimulates the activity of the GnRH pulse generator interacting with opioid neurons in rats in proestrus

In order to investigate the possibility that i.p. injection of pentobarbital sodium (PB, 32 mg/kg bw) potentiates the GnRH pulse generator activity, effects of i.v. infusions of an opiate receptor antagonist naloxone (NAL, 2 mg/h) on the pulsatile LH secretion were compared in saline (SAL)- and PB-injected rats in proestrus and diestrus 1. In SAL-injected rats in proestrus, NAL infusions significantly increased both the frequency and amplitude of LH pulses, and also the overall mean LH concentration. In PB-injected rats in proestrus, all the parameters of the pulsatile LH secretion were similar to those in SAL-injected rats in proestrus. The NAL infusion in PB-injected rats caused an increase in the frequency, but it was similar to that in SAL-injected rats. But, increases in the amplitude and the overall mean LH observed during NAL infusions in PB-injected rats were greater than in SAL-injected rats. In SAL-injected rats in diestrus 1, NAL infusions increased all the parameters, as in rats in proestrus. In PB-injected rats in diestrus 1, LH secretion was severely suppressed. NAL infusions recovered the pulsatile LH secretion, but the frequency and the overall mean LH of the secretion were smaller than those obtained during NAL infusions in SAL-injected rats. In addition, characteristic increases in the MUA (volleys), which occur in association with the initiation of an LH pulse and thus are considered to represent an increased activity of the GnRH pulse generator, appeared more frequently during NAL infusions in PB-injected rats in proestrus than in SAL-injected rats. These results suggest that the GnRH pulse generator in rats in proestrus, but not in rats in diestrus 1, is refractory to PB and further is potentiated by PB in the response to NAL. Together with the fact that this dosage of PB blocks the surge of LH secretion in rats in proestrus, the concept of the existence of separate neuronal mechanisms responsible for the surge and pulsatile secretion of LH are supported.

The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff

We investigated the function of biceps in 18 patients (19 shoulders) with lesions of the rotator cuff. Their mean age was 59 years. Another series of 18 patients (19 shoulders) with normal rotator cuffs as seen on MRI acted as a control group. Their mean age was 55 years. A brace was used to maintain contraction of biceps during elevation. Anteroposterior radiographs were obtained with the arm elevated at 0°, 45° and 90° with and without contraction of biceps. The distance between the centre of the head of the humerus and the glenoid was compared in the two groups.

We found that in the group with tears there was significantly greater proximal migration of the head of the humerus at 0° and 45° of elevation without contraction of biceps but depression of the head of the humerus at 0°, 45° and 90° when biceps was functioning. We conclude that biceps is an active depressor of the head of the humerus in shoulders with lesions of the rotator cuff.

The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff

We investigated the function of biceps in 18 patients (19 shoulders) with lesions of the rotator cuff. Their mean age was 59 years. Another series of 18 patients (19 shoulders) with normal rotator cuffs as seen on MRI acted as a control group. Their mean age was 55 years. A brace was used to maintain contraction of biceps during elevation. Anteroposterior radiographs were obtained with the arm elevated at 0 degrees , 45 degrees and 90 degrees with and without contraction of biceps. The distance between the centre of the head of the humerus and the glenoid was compared in the two groups. We found that in the group with tears there was significantly greater proximal migration of the head of the humerus at 0 degrees and 45 degrees of elevation without contraction of biceps but depression of the head of the humerus at 0 degrees, 45 degrees and 90 degrees when biceps was functioning. We conclude that biceps is an active depressor of the head of the humerus in shoulders with lesions of the rotator cuff.

Does severe nutcracker phenomenon cause pediatric chronic fatigue?

BACKGROUND

In the past five years we experienced 9 fatigued disabled children who were intermittently or persistently absent from school.

PATIENTS

They had been suspected to be burdened with psychosomatic disorders, having orthostatic hypotension, postural tachycardia, or other autonomic dysfunction symptoms.

RESULTS

Investigating the cause of moderate orthostatic proteinuria in some of them, we found by chance severe typical nutcracker phenomenon (NC), which was present in all 9 children complaining of chronic fatigue.

CONCLUSION

Their symptoms filled the criteria of chronic fatigue syndrome or idiopathic chronic fatigue (CFS/CF). An association between severe NC and autonomic dysfunction symptoms in children with CFS/CF has been presented.

Development of a rapid positive/absent test for coliforms using sensitive bioluminescence assay

We have developed a sensitive bioluminescence assay for beta-galactosidase using a luminescent substrate, D-luciferin-O-beta-galactopyranoside (LuGal). The detection limit for beta-galactosidase was 3 x 10-20 mol per assay, which was approximately 50-fold more sensitive than the test using a fluorescent substrate. This assay was applied to a positive/absent (P/A) test for coliforms. Observations made after 7 h of culture followed by a 10-min enzyme assay using LuGal were comparable to those made after a 22-24-h culture by the current method. Therefore, the LuGal method allows a rapid P/A test for coliforms.

The crystal structure of a Dcp-containing peptide

We have investigated the conformational preferences of a newly synthesized C(alpha,alpha) symmetrically disubstituted glycine, namely alpha,alpha-dicyclopropylglycine (Dcp). We report here the crystal structure of a fully protected dipeptide containing Dcp, namely Z-Dcp(1)-Dcp(2)-OCH(3). Both Dcp residues are in a folded conformation. The overall peptide structural organization corresponds to an alpha-pleated sheet conformation, similar to that observed in linear peptides made up of alternating D- and L-residues and in Z-Aib-Aib-OCH(3) (Aib: alpha,alpha-dimethylglycine). These preliminary data suggest that the Dcp could represent an alternative as molecular tool to stabilize folded conformations.

The human serotonin transporter gene linked polymorphism (5-HTTLPR) shows ten novel allelic variants

The serotonin transporter (5-HTT) gene is a promising candidate for introducing the heritability of interindividual variation in personality and the genetic susceptibility for various psychiatric diseases. Transcription of the gene is modulated by a common polymorphism in its upstream regulatory region (5-HTT gene-linked polymorphic region: 5-HTTLPR). The 5-HTTLPR consists of variation of the repetitive sequence containing GC-rich, 20-23-bp-long repeat elements. A deletion/insertion in the 5-HTTLPR was first reported to create a short (S) allele and a long (L) allele (14- and 16-repeats, respectively). Three other kinds of alleles (18-, 19- and 20-repeats) in addition to the S and L alleles in 5-HTTLPR have been reported. In the present study, we examined the 5-HTTLPR polymorphism in detail and identified ten novel sequence variants, concluding that the alleles reported as S and L are divided into four and six kinds of allelic variant, respectively. Subsequently, we developed a method for genotyping. The total number of alleles (14-A, 14-B, 14-C, 14-D, 15, 16-A, 16-B, 16-C, 16-D, 16-E, 16-F, 19, 20 and 22) in the 5-HTTLPR was 14 in our populations (Japanese: n = 131; Caucasian: n = 74) in the present study. In addition, a significant ethnic difference between Japanese and Caucasian populations was observed for distributions of alleles and genotypes (P < 0.0001 and P < 0.0001, respectively). Our results suggest that the analyses of the 5-HTTLPR should be revised by genotyping with a more complete subdivision of alleles. Molecular Psychiatry (2000) 5, 32-38.

[Laser photocoagulation for choroidal neovascularization developed in a patient with optic disc drusen and angioid streaks]

BACKGROUND

Optic disc drusen accompanied by angioid streaks is rarely seen in Japan. Laser photocoagulation for choroidal neovascularization (CNV) in patients with angioid streaks is controversial.

CASE

A 45-year-old woman presented with bilateral papilledema. Clinical examination revealed optic disc drusen and angioid streaks. During the follow-up period, juxtapapillary CNV developed in both eyes. CNV in the right eye developed progressively towards the fovea and was eventually treated by laser, but the CNV in the left eye regressed spontaneously.

CONCLUSION

These are the first precise clinical records on optic disc drusen with angioid streaks to be reported. The outcome of laser treatment for CNV in this case was favorable, because alteration of Bruch's membrane was mild, in the form of angioid streaks.

Microstructure and release characteristics of the minipellet, a collagen-based drug delivery system for controlled release of protein drugs

We have developed the minipellet, a matrix-type system for the sustained delivery of protein drugs using collagen as a biodegradable drug carrier. In this study, we analyzed the microstructure and release profile of the minipellet containing human serum albumin (HSA) as a model drug.The findings suggest that the minipellet has a structure in which collagen fibers are strongly oriented in the direction of extrusion from the nozzle in the molding process of the minipellet, and that HSA exists as fine particulate clusters which are homogeneously distributed among the collagen fibers in the minipellet. During release, the HSA clusters dissolve and HSA is retained within the collagen matrix as a solution.The results of release experiments indicate that HSA release from the minipellet is mainly controlled by diffusion in the collagen matrix, and that sustained release is achieved by the dense structure of the collagen matrix which is formed in the manufacture process. In addition, more detailed study suggests that the minipellet has unique directional release behavior caused by its microstructure.

BDNF atelocollagen mini-pellet accelerates facial nerve regeneration

We investigated the effect of BDNF mini-pellet on the GAP-43 mRNA expression and functional status of facial nerve in a rat model of facial nerve transection and immediate repair. The facial function started to recover at 17 days in the placebo group and 14 days in the BDNF group. BDNF group had shorter period of increased GAP-43 mRNA expression than the placebo group. Topically applied BDNF may accelerate the facial nerve regeneration.

Identification of a novel polymorphism of the human dopamine transporter (DAT1) gene and the significant association with alcoholism

Human dopamine transporter gene (DAT1) has a variable number of tandem repeats (VNTR) in its 3'-untranslated region (UTR). The association between the VNTR polymorphism and neuropsychiatric disorders has been studied, but their relationship is still unclear. Here we identified a novel polymorphism in the 3'-UTR of the DAT1 gene, G2319A, and a significant association between the polymorphism and alcoholism was observed in both genotypic and allelic frequencies (P = 0.040 and 0.019, extended Fisher's exact test, respectively). There was a significant gene dose effect on the risk for alcoholism associated with the 2319-A allele (chi2 = 6.16, df = 2, P = 0.046, linearity tendency test: Cochranq-Armitage analysis). Moreover, in the haplotype analysis with G2319A- and VNTR-polymorphisms, a positive gene dose efffect on the risk with the A10 allele (P = 0.044, linearity tendency test) and a negative gene dose effect with the G10 allele (P = 0.010, linearity tendency test) for alcoholism were significantly detected. Odds ratio for alcoholism with the A10 and G10 alleles were 1.76 (1.12-2.76) and 0.53 (0.32-0.79), respectively. These results indicate that the DAT1 gene may confer vulnerability to alcoholism.