Two percent of patients suspected of having Angelman syndrome have TCF4 mutations

The TCF4 gene encodes a basic helix-loop-helix (bHLH) transcription factor which belongs to the family of E-proteins. E-proteins form homo- and heterodimers with other members of the HLH family and bind to the common DNA sequence called E-box. Haploinsufficiency of the TCF4 gene has been found to be associated with the Pitt-Hopkins syndrome (PTHS). PTHS is characterized by severe mental retardation, a wide mouth plus other distinctive facial features (fleshy lips, beaked nose, broad nasal bridge) and breathing abnormalities. Because of some phenotypical overlap with Angelman syndrome (AS), it has been suggested that PTHS be considered in its differential diagnosis. To explore this possibility, we screened 86 patients who were suspected of having AS. All the patients were negative for UBE3A testing, and 53 were known to be negative for methylation analysis. We identified two TCF4 mutations in this cohort. The p.S384Tfsx7 mutation lacks the bHLH domain. The p.R582P mutation lies within the bHLH domain in which seven other missense mutations have been reported. Both mutations most likely affect the critical function of the bHLH domain of the TCF4 protein. In summary, we found two TCF4 mutations in 86 patients (2%) suspected to have AS. Screening for mutations in this gene should be considered in patients who present with findings of AS but who have been negative for methylation and UBE3A testing.

Subtilisin-like serine protease from hyperthermophilic archaeon Thermococcus kodakaraensis with N- and C-terminal propeptides

The genome of the hyperthermophilic archaeon Thermococcus kodakaraensis contains three genes encoding subtilisin-like serine proteases, Tk-1689, Tk-0076 and Tk-subtilisin. Of them, the structure and function of Tk-subtilisin have been extensively studied. To examine whether Tk-1689 is matured to an active form and functions as a hyperthermostable protease as is Tk-subtilisin, the gene encoding the Tk-1689 derivative without a putative N-terminal signal sequence, termed Pro-Tk-SP, was overexpressed in Escherichia coli. Pro-Tk-SP is composed of 640 amino acid residues and its molecular mass is 68.6 kDa. The recombinant protein was purified, however, as an active 44 kDa protease, termed Tk-SP, which lacks the N-terminal 113 and C-terminal 101 amino acid residues. This result suggests that Pro-Tk-SP consists of an N-terminal propeptide (Ala1-Ala113), a mature domain (Tk-SP, Val114-Val539) and a C-terminal propeptide (Asp540-Gly640). Like Tk-subtilisin, Tk-SP showed a broad substrate specificity and was highly thermostable. Its optimum temperature for activity was approximately 100 degrees C and its half-life at 100 degrees C was 100 min. It was fully resistant to treatment with 5% SDS, 8 M urea or 10% Triton X-100. However, unlike Tk-subtilisin and bacterial subtilisins, Tk-SP requires neither Ca2+ nor propeptide for folding. As a result, Tk-SP was fully active even in the presence of 10 mM EDTA. Thus, Tk-SP has a great advantage over other proteases in high resistance to heat, denaturants, detergents and chelating agents and therefore has great potential for application in biotechnology fields.

Safety and efficacy of growth hormone (GH) during extended treatment of adult Japanese patients with GH deficiency (GHD)

OBJECTIVES

To assess the effects of a growth hormone (GH) replacement therapy using a GH dose regimen based on serum insulin-like growth factor (IGF-I) concentrations in Japanese adults with GH deficiency (GHD).

DESIGN

In this multicentre, uncontrolled, open-label study, Japanese adults with GHD who had received either GH replacement therapy (GH-GH group, n=35) or placebo (Placebo-GH group, n=36) in a previous randomised, double-blind, placebo-controlled trial were treated with GH replacement therapy for 48 weeks. GH treatment was started at a dose of 0.003 mg/kg/day administered by subcutaneous injection for the first 8 weeks, after which the dose was adjusted to maintain patients' serum IGF-I levels within the reference range adjusted for age and gender. Body composition, serum lipids, serum IGF-I and IGF binding protein-3 (IGFBP-3) levels were measured throughout study. Symptom and quality of life scores were also determined.

RESULTS

Lean body mass (LBM) was increased compared with baseline (the end of the preceding double-blind trial) at 24 and 48 weeks, with a mean (+/-SD) increase of 1.3% (+/-4.2%) at week 48 in the GH-GH group (an increase of 6.6% [+/-6.0%] from the start of the preceding double-blind trial) and a larger increase of 4.7% (+/-5.9%) in the Placebo-GH group. Body fat mass (BFM) increased slightly from baseline in the GH-GH group with a mean increase of 2.9+/-10.6% at week 48 (a decrease from the start of the preceding double-blind trial at 48 weeks of 7.8% [+/-15.0%]) but decreased by 6.5% (+/-11.7%) at week 48 in the Placebo-GH group. Serum lipids were unchanged or slightly increased from baseline in the GH-GH group but patients' lipid profiles improved in the Placebo-GH group. In patients who received placebo during the double-blind study, individualised GH therapy in this open-label study increased mean LBM at 48 weeks by 6.2+/-6.8% in patients with CO GHD and by 3.0+/-4.4% in patients with AO GHD. Changes in mean LBM and mean BFM at week 48 were +4.1+/-4.5% and -2.4+/-10.5%, respectively, in females and +5.0+/-6.7% and -8.9+/-11.8%, respectively, in males. In patients who received GH treatment during the double-blind study, overall changes in LBM, BFM and IGF-I SD score after 24 weeks and 48 weeks were small, with no significant differences between subgroups. While the overall incidence of adverse events was broadly similar in the GH-GH and Placebo-GH groups (97% and 89%, respectively), the incidence of treatment-related events was higher in the GH-GH group (83% vs 42% in the Placebo-GH group). Most adverse events in both treatment groups were of mild or moderate severity and not clinically significant. The incidences of oedema and cases of high IGF-I during the IGF-I level-adjusted treatment regimen were lower than those during the preceding fixed dose titration.

CONCLUSION

Long-term GH replacement therapy was well tolerated in Japanese adults with GHD. GH treatment maintained the improvements in body composition and lipid profiles in the patients previously treated in the double-blind study (GH-GH group) and improved these parameters in previously untreated patients (Placebo-GH group). Individualised GH administration based on IGF-I levels was well-tolerated and effective.

Actinobacillus actinomycetemcomitans lipopolysaccharide stimulates collagen phagocytosis by human gingival fibroblasts

INTRODUCTION

Collagen phagocytosis by fibroblasts is involved in the intracellular pathway related to collagen breakdown in soft connective tissues. The possible role of lipopolysaccharide (LPS) in regulating this fibroblast function has not been elucidated so we investigated the effect of LPS from Actinobacillus actinomycetemcomitans, a periodontopathic bacterium, on collagen phagocytic activity in human gingival fibroblasts and associated regulatory mechanisms.

METHODS

LPS pretreatment stimulated binding of collagen-coated beads to cells and, subsequently, their internalization.

RESULTS

The LPS-activated collagen phagocytic process was enhanced in the presence of the soluble form of CD14 (sCD14) or LPS-binding protein (LBP), while the LPS/LBP treatment activated Akt and induced actin reorganization. Furthermore, these LPS/LBP-induced effects were partially suppressed by adding phosphatidyl-inositol-3 kinase (PI3K) inhibitors.

CONCLUSION

These results suggest that A. actinomycetemcomitans LPS disturbs the homeostasis of collagen metabolism within gingival tissue by facilitating collagen phagocytosis by gingival fibroblasts, and serum sCD14 and LBP positively regulate the action of LPS. In addition, the PI3K/Akt signaling is thought to partially mediate the LPS/LBP-stimulated collagen phagocytic pathway, which may be dependent on actin cytoskeletal rearrangement.

Protein crystallization in a 100 nl solution with new stirring equipment

To investigate quantitatively the effects of stirring on protein crystallization, a new stirring system which can agitate a protein solution, approximately 100 nl, by providing Hagen-Poiseuille flow has been successfully developed. In addition, this new stirring system provides flow with a well defined pattern and velocity. Using this system, hen egg-white lysozyme was crystallized in 100-200 nl solutions while being stirred. The optimum stirring conditions for lysozyme crystals have been explored by evaluating the Reynolds (Re) number and the crystals obtained. Intermittent flow, as well as a low Re number, was found to contribute significantly to the growth of a smaller number of larger crystals.

148 PRODUCTION OF PUPS BY OVARIAN TRANSFER IN THE SYRIAN HAMSTER

Instead of gametes, ovaries could be used as alternative resources for cryopreservation. In this study, we attempted to produce pups by transplantation of fresh ovaries to foster mothers as a first step to establish a preservation method of hamster strains on the basis of the cryopreservation of ovaries in combination with ovarian transfers. We also checked the possibility of inter-strain transfers of ovaries, since immunological tolerance among hamster strains is suggested by the fact that most Syrian hamsters were derived from only a small number of animals. Fresh ovaries collected from 3-weekold females of HAW (white coat) and APA (albino) strains were transferred into ovarian bursae of 3-week-old recipient females with agouti-coat (Slc:Syrian) under anesthesia with xylazine and ketamine. Halves of ovaries of recipients were removed immediately before the transfers, i.e., both donor and recipient ovaries were present in each ovarian bursa. Successful transplantation of ovaries was checked by the coat color (non-agouti color) of offspring produced by test matings of recipients with Slc:Syrian males after the recipients became mature. Five and six recipients received HAW and APA ovaries, respectively. All 11 recipients tested became pregnant and delivered pups. According to the coat color of the pups, three of five recipients which received HAW ovaries and one of six recipients which received APA ovaries delivered pups derived from transplanted ovaries (two out of eight pups, one out of seven pups, and three out of 11 pups for HAW; one out of five pups for APA). Our results indicate that transplantation of fresh ovaries to foster mothers could be used for production of pups from grafted ovaries in the Syrian hamster. In particular, immunological tolerance for ovarian transfers among at least three strains suggests that recipient strains might not need to be the same as donor strains for practical ovarian transfers in the Syrian hamster. Our results would facilitate the development of a strain preservation system for the Syrian hamster based on ovarian cryopreservation. This work was supported by a grant from the Ministry of Health, Labor, and Welfare of Japan.

Two routes for pollen entering indoors: ventilation and clothes

BACKGROUND

The route by which pollen enters dwellings has not been clarified.

OBJECTIVE

To evaluate the amount of pollen entering dwellings by ventilation and adhesion to textile products.

METHODS

The amount of pollen clinging to fabrics (clothes, laundry, and futon bedding) out of doors was measured by quantification of Japanese cedar pollen antigen Cry j 1. The effect of air ventilation on the amount of pollen indoors was also investigated using several neighboring unoccupied apartments with an identical layout while controlling the ventilation conditions.

RESULTS

The amount of pollen adhering to futons was especially high. More than half of the pollen on futons or laundry remained on the surface, even after being brushed off by hand or shaken off. Vacuuming laundry and futons after airing out would be an effective way to decrease the amount of indoor pollen. A large amount of pollen entered dwellings through air ducts when the windows were closed and the ventilation fans working. Since most pollen that entered by ventilation remained near the windows, cleaning carefully and frequently near windows could reduce the amount of pollen indoors.

CONCLUSIONS

To decrease the amount of pollen indoors, special attention must be paid to textile products and ventilation systems during the pollen season.

Directed evolution of Tk-subtilisin from a hyperthermophilic archaeon: identification of a single amino acid substitution responsible for low-temperature adaptation

Tk-subtilisin from the hyperthermophilic archaeon Thermococcus kodakaraensis is synthesized in a prepro-form (prepro-Tk-subtilisin), secreted in a pro-form (pro-Tk-subtilisin), and matured to an active form (mat-Tk-subtilisin*; a Ca(2+)-bound active form of matured domain of Tk-subtilisin) upon autoprocessing and degradation of the propeptide [Tk-propeptide; propeptide of Tk-subtilisin (Gly1-Leu69)]. Pro-Tk-subtilisin exhibited halo-forming activity only at 80 degrees C, but not at 70 and 60 degrees C, because Tk-propeptide is not effectively degraded by mat-Tk-subtilisin* and forms an inactive complex with mat-Tk-subtilisin* at <80 degrees C. Random mutagenesis in the entire prepro-Tk-subtilisin gene, followed by screening for mutant proteins with halo-forming activity at 70 and 60 degrees C, allowed us to identify single Gly56 --> Ser mutation in the propeptide region responsible for low-temperature adaptation of pro-Tk-subtilisin. SDS-PAGE analyses and mat-Tk-subtilisin* activity assay of pro-G56S-subtilisin indicated more rapid maturation than pro-Tk-subtilisin. The resultant active form was indistinguishable from mat-Tk-subtilisin* in activity and stability, indicating that Gly56 --> Ser mutation does not seriously affect the folding of the mature domain. However, this mutation greatly destabilized the propeptide, making it unstructured in an isolated form. As a result, Tk-propeptide with Gly56 --> Ser mutation (G56S-propeptide) was more susceptible to proteolytic degradation and less effectively inhibited mat-Tk-subtilisin* activity than Tk-propeptide. These results suggest that pro-G56S-subtilisin is more effectively matured than pro-Tk-subtilisin at lower temperatures, because autoprocessed G56S-propeptide is unstructured upon dissociation from mat-Tk-subtilisin* and is therefore effectively degraded by mat-Tk-subtilisin*.

Arrangement of fiber tracts forming Probst bundle in complete callosal agenesis: report of two cases with an evaluation by diffusion tensor tractography

We report two patients with complete callosal agenesis in whom Probst bundles in both hemispheres could be depicted by diffusion tensor tractography (DTT). While one patient had no associated telencephalic anomaly other than callosal agenesis, the other had cortical dysplasia in the right frontal lobe. Although Probst bundles in the three normal hemispheres were well developed, that in the hemisphere which was affected by cortical dysplasia was small and poorly developed. DTT also showed that the fibers from the frontal pole ran more on the inner side of the Probst bundle than those from a more caudal region of the frontal lobe. Furthermore, fibers from the orbital gyri ran along the outermost side of Probst bundle. The arrangement of these fiber tracts in Probst bundle may reflect the developmental process of callosal fibers in their normal formation.

Extracellular secretion of Escherichia coli alkaline phosphatase with a C-terminal tag by type I secretion system: purification and biochemical characterization

Type I secretion system (TISS) of Gram-negative bacteria permits proteins to be secreted directly from the cytoplasm to the external medium by a single, energy-coupled step. To examine whether this system can be used as an extracellular production system of recombinant proteins, Escherichia coli alkaline phosphatase (AP) was fused to a C-terminal region of Pseudomonas sp. MIS38 lipase (PML) and examined for secretion using the E.coli cells carrying the heterologous TISS. PML is one of the passenger proteins of TISS and contains 12 repetitive sequences and a secretion signal at the C-terminal region. The fusion protein was efficiently secreted to the extracellular medium, while AP was not secreted at all, indicating that the secretion of AP is promoted by a secretion signal of PML. The repetitive sequences were not so important for secretion of the fusion protein, because the secretion level of the fusion protein containing entire repeats ( approximately 10 mg/l culture) was only 2-fold higher than that of the fusion protein without repeats. The fusion protein purified from the culture supernatant existed as a homodimer, like AP, and was indistinguishable from AP in enzymatic properties and stability.