Isomorphic coalescence of aster cores formed in vitro from microtubules and kinesin motors.

We report fluorescence microscopy studies of the formation of aster-like structures emerging from a cellular element-based active system and a novel analysis of the aster condensation. The system consists of rhodamine labeled microtubules which are dynamically coupled by functionalized kinesin motor proteins cross-linked via streptavidin-coated quantum dots (QDs). The aster-shaped objects contain core structures. The cores are aggregates of the QD-motor protein complexes, and result from the dynamic condensation of sub-clusters that are connected to each other randomly. The structural specificity of the aster core reflects a configuration of the initial connectivity between sub-clusters. Detailed image analysis allows us to extract a novel correlation between the condensation speed and the sub-cluster separation. The size of the core is scaled down during the condensation process, following a power law dependence on the distance between sub-clusters. The exponent of the power law is close to two, as expected from a geometric model. This single exponent common to all the contractile lines implies that there exists a time regime during which an isomorphic contraction of the aster core continues during the condensation process. We analyze the observed contraction by using a model system with potential applicability in a wide range of emergent phenomena in randomly coupled active networks, which are prevalent in the cellular environment.

Bioassisted capture and release of nanoparticles on nanolithographed ZnO films.

Using an artificial peptide library, we have identified a peptide that has strict selective affinity for ZnO surfaces. The binding affinity of the peptide on the ZnO surface can be controlled simply through changes in phosphate concentration at constant pH and temperature. In this study, we functionalized inorganic nanoparticles by orderly conjugating ZnO-binding peptides (ZnOBPs) on the surface of cadmium selenide (CdSe) nanoparticles and performed spontaneous and reversible nanopatterning of ZnOBP-displayed nanoparticles on lithographed ZnO films. Conjugation of ZnOBPs on CdSe nanoparticles caused spontaneous adsorption of the nanoparticles on a ZnO film, and fluorescence and cathodoluminescence images clearly showed specific adsorption of nanoparticles on the ZnO films lithographed on nano- and micrometer scales. The selectively bound nanoparticles on ZnO films were completely released by changing the phosphate concentration in solution; such release did not require heat or mechanical applications. Repeated capture and release of nanoparticles were achieved on the micrometer scale. Our results show the potential of material-binding peptides for nanopatterning and dynamic microarrays.

Unilateral adrenalectomy improves insulin resistance and polycystic ovaries in a middle-aged woman with virilizing adrenocortical adenoma complicated with Cushing's syndrome.

A benign virilizing adrenal adenoma is rare among adrenal neoplasms in middle-aged women. A 39-yr-old Japanese woman who presented with hirsutism, obesity, diabetes mellitus and hypertension was admitted. Plasma concentrations of testosterone and DHEAS were high. While the basal level of plasma ACTH was suppressed, serum cortisol level was high and its circadian rhythm was absent. Serum cortisol level was not suppressed with the low- and high-dose overnight dexamethasone suppression test. Abdominal computed tomography showed a left adrenal tumor, and an adrenocortical scintigraphy revealed uptake of the tracer on the left side. Polycystic ovaries were also found and bone mineral density revealed osteoporosis. Histopathological features of resected adrenal tumor were consistent with those of adrenocortical adenoma. Immunoreactivity of all the steroidogenic enzymes was apparent in the tumor cells and particularly dehydroepiandrosterone sulfotransferase (DHEA-ST) immunoreactivity was markedly expressed. Cortical atrophy and reduced expression of DHEA-ST were detected in the cortex of the adjacent non-neoplastic adrenal gland. Plasma testosterone, DHEAS and cortisol levels returned to normal after surgery, concomitantly with the disappearance of polycystic ovaries. This is a very rare case of virilizing adrenocortical adenoma complicated with Cushing's syndrome (CS).

Modulating the microtubule-tau interactions in biomotility systems by altering the chemical environment.

Obstacles in microtubule mediated neuronal transport can trigger dementia. We use bio-motility assays, that simulate the neuron chemistry in axonopathy, to screen chemicals, that retain the microtubule dynamics in healthy neuronal activity. Tau protein inhibits microtubule activity and leads to oligomerization. Iron(iii) untangles, whereas mono-sodium-glutamate destabilizes the microtubule oligomer.

Interaction of photosynthetic pigments with various organic solvents 2. Application of magnetic circular dichroism to bacteriochlorophyll a and light-harvesting complex 1.

Magnetic circular dichroism (MCD) and absorption spectra of metal bacteriochlorin complexes have been measured on bacteriochlorophyll (BChl) a in various solvents and different forms of light-harvesting complexes 1 (LH1 complexes). In hydrophilic organic solvents, the MCD intensity of the Q(y)(0-0) transition of BChl a was sensitive to the wavelength of absorption maximum of Q(x)(0-0), and the ratio of MCD Q(y)(0-0) intensity to the dipole strength (B/D) was inversely proportional to the difference in energy between the Q(x)(0-0) and Q(y)(0-0). The similar correlation has been observed in metal chlorin derivatives as previously reported. The correlation depends on the coordination number of the Mg atom in BChl a and the molecules ligating to it. In a hydrophobic solvent such as carbon tetrachloride (CCl(4)), however, the correlation did not hold because of the existence of aggregates. Hence, the correlation between the values of B/D and the energy difference can be used to estimate the type and number of the molecules ligated to the Mg atom and to disclose the existence of aggregated pigments. We further apply the correlation to the LH 1 complex treated with n-octyl beta-D-glucopyranoside.

Interaction of photosynthetic pigments with various organic solvents. Magnetic circular dichroism approach and application to chlorosomes

Magnetic circular dichroism (MCD) and absorption spectra have been measured on three intact photosynthetic pigments with the chlorin ring as macrocycle: chlorophyll a, bacteriochlorophyll c and d, in various hydrophilic organic solvents. The MCD intensity of a Qy(0-0) transition for the Mg chlorin derivative was sensitive to the coordination state of the central Mg atom by the solvent molecules. The coordination number has been characterized in terms of the relationship between the ratio of Qy(0-0) MCD intensity to its dipole strength (B/D) and the difference in energies of Qx(0-0) and Qy(0-0) transitions. This relationship depends not only on the coordination number of the magnesium (Mg) atom but also on the coordination interaction of the solvent molecules to the Mg atom, and can clarify the spectroscopic change of chlorosomes by alcohol treatment. We propose that the correlation between the MCD intensity of Qy(0-0) transition and the energy difference can be used as a new measure for determining the coordination number of the Mg atom and for estimating the interaction strength of the Mg atom with solvent molecules.

Chronic respiratory disease in premature infants caused by Chlamydia trachomatis.

The relation between chronic respiratory disease and infection with Chlamydia trachomatis in premature infants was investigated to ascertain the aetiological importance of intrauterine C trachomatis infection and chronic respiratory disease in premature infants. Serum IgM antibodies against C trachomatis were determined by enzyme linked fluorescence assay. Sections of lung tissues obtained by biopsy and at necropsy were also tested for the presence of antigens using fluorescein conjugated monoclonal antibodies to C trachomatis. Of 16 sera from premature infants with chronic respiratory diseases clinically diagnosed as bronchopulmonary dysplasia or the Wilson-Mikity syndrome, five had IgM antibodies to C trachomatis L2 strain by enzyme linked fluorescence assay (titre greater than or equal to 1/500). Of 37 sera from premature infants with extremely low birth weights, two had IgM antibodies to C trachomatis. No specific IgM antibody was detected in 31 neonates who showed raised serum IgM concentrations but who did not have respiratory tract symptoms. C trachomatis was identified from two specimens of lung tissue obtained at necropsy from premature infants with chronic respiratory disease positive for IgM antibody. These findings indicate the aetiological importance of intrauterine C trachomatis infection in chronic respiratory disease in premature infants.

Therapeutic effect of clarithromycin for respiratory-tract infections in children caused by Chlamydia pneumoniae. Research Group of Sapporo for Pediatric Chlamydial Infections.

Children infected with Chlamydia pneumoniae sometimes experience lower respiratory tract infections such as pneumonia and bronchitis. Although numerous anti-microbial compounds have been reported to be active against the organism, most of them have not been in a clinical trial in infants and children with C. pneumoniae infection. Clarithromycin has been shown to express anti-chlamydial effects in vitro. In this study, we evaluated the clinical anti-C. pneumoniae properties of clarithromycin in children with mainly lower respiratory tract infection. We administered clarithromycin orally to 21 infants and children at a dose of 10-15 mg/kg/day divided into two or three doses for 4-21 days. Clinical symptoms, roentgenographic and laboratory abnormal findings improved. The overall clinical efficacy rate was 85.7% (18 of 21 cases). Administration of clarithromycin was considered to be a suitable treatment for improving lower respiratory infections in infants and children caused by C. pneumoniae.

Discrimination between cardiac para- and sympathetic damage in diabetics.

To analyze the autonomic mechanism on heart rate (HR) variations, pharmacological studies were performed on 8 healthy subjects and 6 diabetic patients. Three HR variations--in supine resting position, during deep breathing in supine position (respiratory HR variations), and on standing (orthostatic tachycardia; delta HR)--were examined. The results in healthy subjects and diabetics were similar. After administration of parasympathetic blockade with atropine, respiratory HR variations were almost abolished. However, no significant difference in delta HR was found. With the addition of beta-adrenergic blockade with propranolol, delta HR was remarkably reduced. Propranolol alone did not affect the respiratory HR variations, but after propranolol administration delta HR was significantly reduced compared with that of the control. The present studies show that respiratory HR variations are predominantly mediated by parasympathicus, whereas orthostatic tachycardia is mediated by both sympathicus and parasympathicus, particularly by sumpathicus. This result suggests the possibility of discriminating the impairment of the 2 cardiac autonomic nervous systems by these simple and non-invasive tests.

Detection of IgM antibodies to Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci from Japanese infants and children with pneumonia.

Chlamydia trachomatis (C. trachomatis) is now well established as a pathogen of neonatal inclusion conjunctivitis and infantile pneumonia. C. pneumoniae (TWAR) and C. psittaci also cause pneumonia and other respiratory infections. Serum samples from 223 Japanese infants and children with pneumonia were tested for IgM antibodies to C. trachomatis, C. pneumoniae and C. psittaci. IgM antibodies to C. trachomatis were measured by an enzyme immunoassay (EIA) and by a microimmunofluorescence (MIF) test. IgM antibodies to C. pneumoniae and C. psittaci were determined by MIF. Of 223 patients, 48 (21.5%) were positive for IgM antibodies to C. trachomatis, 11 (4.9%) were positive for C. pneumoniae and 5 (2.2%) were positive for C. psittaci. From nasopharyngeal swabs collected from 87 infants with pneumonia (0 to 1 year of age), we attempted to isolate C. trachomatis with tissue culture. C. trachomatis was isolated from 23 (26.4%) of 87 infants with pneumonia, and IgM antibodies to C. trachomatis were detected in 17 (19.5%) of them. Our data suggest a role for chlamydial infection in childhood pneumonia beyond infancy with both C. trachomatis and C. pneumoniae being contributing pathogens.

[Evaluation of chlamydial IgM antibodies for clinical diagnosis].

Chlamydia trachomatis (C. trachomatis), C. psittaci, and C. pneumoniae are now well established as pathogens of respiratory infections including pneumonia. Serum samples from 223 infants and children with pneumonia, 31 patients with adult inclusion conjunctivitis, 16 parents of babies with neonatal inclusion conjunctivitis and others were tested for IgM antibodies to Chlamydiae. Diagnostic kits for chlamydial IgM antibodies (SeroELISA and IPAzyme) have been also evaluated for their diagnostic value. It was found that detection of specific IgM antibodies with SeroELISA has a diagnostic value in chlamydial pneumonias.

[Antimicrobial susceptibility patterns of the Proteeae in Japan, 1989].

We discussed the antimicrobial susceptibilities of Proteeae isolated in Japan, 1989. Eight hundred six clinical isolates were collected from 47 hospitals. These were comprised of 431 strains of Proteus mirabilis, 155 Proteus vulgaris, 154 Morganella morganii, 44 Providencia rettgeri and 22 Providencia stuartii. Antibiotics tested in this study were 2 penicillins, 5 cephems, 1 carbapenem and 2 aminoglycosides. The MIC's were determined using the standard method of the Japan Society of Chemotherapy. Susceptibilities of the above strains to these antibiotics are described below; 1. Latamoxef, ceftizoxime and imipenem had excellent activities with no evident differences among the species of Proteeae. 2. Ampicillin and cefazolin were less active against Indol-positive Proteeae. 3. Piperacillin and cefmetazole were also strongly active drugs against P. mirabilis, P. vulgaris and P. stuartii, and cefotiam against P. mirabilis and P. stuartii. 4. Gentamicin and netilmicin showed excellent activities against M. morganii.

A case of reversed pituitary dysfunction with intrasellar mass.

Hypopituitarism can be caused by tumor, inflammation, granuloma and injuries. Once pituitary function is disturbed, hormone replacement therapy is necessary for the remaining life span in most cases. We have experienced a rare case of a unique intrasellar mass associated with pituitary dysfunction in which both spontaneously reversed. A 61-yr-old woman developed hypoadrenalism and central diabetes insipidus (cDI). Magnetic resonance (MR) imaging revealed a lobular, strong hypointense lesion with spotty signal in the middle of the hypophysis. This spotty lesion showed isointensity on T1- and high-intensity on T2-weighted MR images. The spotty signal as well as the normal pituitary lobe were enhanced by the administration of gadolinium. As replacement therapies for hypoadrenalism and cDI, 10 mg of hydrocortisone and 2.5 microg of desmopressin acetate were prescribed. Three months later, slight shrinkage of intrasellar mass and spontaneous improvement of pituitary functions were found. Hydrocortisone was then discontinued. Furthermore, because polyuria and polydipsia were improved nine months later, desmopressin acetate was stopped. Currently, the intrasellar mass continues to shrink, and the patient shows no symptoms without medication. Based upon the unique features of MR images, we suspect that the origin of the mass is an intrasellar hemangioma.

A sero-epidemiological survey of gelatin sensitization in young Japanese children during the 1979-1996 period.

Recently, an increasing number of adverse reactions in children inoculated with live attenuated virus vaccines containing gelatin have been reported. However, the distribution, magnitude and rate of gelatin sensitization in the Japanese population have not been established. Here, the purpose was to investigate the distribution of children with positive gelatin immunoglobulin G (IgG) and/or IgE in Japan and to ascertain whether the incidence of positive antigelatin antibody cases among the general population, as reflected in the sample employed here, has been increasing during the period in question. The presence of IgE and IgG antibodies were measured against gelatin in 1600 panel sera collected from different age groups of Japanese children in Hokkaido/Sapporo from 1979 through 1996. Among the subjects, 39 had gelatin IgG- and/or IgE-positive sera, and these were correlated with the time of obtaining the sera as well as with the age of the subjects. The older the subject and the later the period, the higher the sero-incidence. Japanese children have become increasingly sensitized to gelatin, especially since the mid-1990s.

A rare case of Gitelman's syndrome presenting with hypocalcemia and osteopenia.

Gitelman's syndrome (GS), an autosomal recessive disorder caused by a defect of the thiazide-sensitive Na-Cl cotransporter (TSC) at the distal tubule, is characterized by hyperreninemic hyperaldosteronism with normal or low blood pressure, hypokalemia, metabolic alkalosis, hypomagnesemia and hypocalciuria. An 18-yr-old Japanese man was admitted to our hospital with a history of muscle weakness and transient tetanic episodes. He showed hypocalcemia in addition to hypokalemia, severe hypomagnesemia, hypocalciuria and hyperreninemic hyperaldosteronism with normal blood pressure. Furthermore, bone mineral density at the lumbar spine revealed osteopenia. A diagnosis of GS was made on the basis of clinical features, laboratory data and renal function test. The electrolyte imbalance was corrected and bone mineral density was slightly increased with chronic treatment of magnesium and potassium salts. Genetic analysis revealed that TSC gene of the patient has a heterozygous C to A nucleotide substitution at position 545 in exon 4, which causes a threonine (Thr) to lysine (Lys) substitution at position 180. This is a rare case of GS with hypocalcemia and osteopenia which could be caused by severe hypomagnesemia.