A new species of Rhacophorus from eastern Thailand (Anura: Rhacophoridae)

A new tree frog of the genus Rhacophorus is described on the basis of specimens collected from Kalasin and Roi Et Provinces, eastern Thailand. It can be distinguished from all other congeners by the combination of: moderate body size (about 38 mm in males and 44 mm in females); brownish dorsum with irregular, dark marking; third finger webbed broadly to base of disk or less on outer side, and fourth finger to distal subarticular tubercle or base of disk; and no dermal appendage on snout, vent, or heel. It is currently known only around the type locality, where habitats suitable for anurans are limited.     

Soft tissue strain and facet face interaction in the lumbar intervertebral joint--Part I: Input data and computational technique

A numerical simulation was devised to determine ligament strains, facet face interaction, and disk fiber strain in the lumbar intervertebral joint under load. This technique uses experimentally derived load deflection and morphologic data from lumbar cadaver specimens from which initial and displaced soft tissue attachment points can be calculated. This allows the strain data to be derived. The effect of disk bulge is also considered. The calculated strains of most ligaments except the facet capsular ligaments were found to be insensitive to anatomical measurement variability of +/- 1 mm.     

New data on the reproductive biology of the thorny stingray,Dasyatis centroura (pisces: Dasyatidae) from off the Tunisian coasts

Synopsis Aspects of the reproductive biology are described for the thorny stingray,Dasyatis centroura, caught off the coasts of Tunis, mainly from the Gulfs of Gabes and Tunis. Sexual maturity in males occurs at a disk width (DW) of 800 mm. Female maturation occurs between 660 mm and 1000mm DW All males and females having a DW greater than 800 and 1000mm, respectively, were adults. Females are larger than males, with adult specimens having an average DW of 1040mm in males and 1345mm in females. Gestation lasts for a minimum of about 4 months. The number of reproductive cycles per year is unknown. Vitellogenesis is completed at the end of the gestation. Parturition and ovulation occur in June. Fecundity ranges from 2 to 6 individuals per litter.     

Osteogenin, a bone morphogenetic protein, adsorbed on porous hydroxyapatite substrata, induces rapid bone differentiation in calvarial defects of adult primates.

Osteogenin, a bone morphogenetic protein, in conjunction with insoluble collagenous bone matrix initiates local endochondral bone differentiation by induction in vivo. This study, by exploiting the affinity of native osteogenin for hydroxyapatite, was designed to construct a delivery system for the expression of the biologic activity of osteogenin in nonhealing calvarial defects of adult primates. After exposure of the calvaria, 64 cranial defects, 25 mm in diameter, were prepared in 16 adult male baboons (Papio ursinus). Defects were implanted with disks of porous nonresorbable and resorbable hydroxyapatite substrata obtained after hydrothermal conversion of calcium carbonate exoskeletons of corals. In each animal, one disk of each hydroxyapatite preparation was treated with osteogenin isolated and purified from baboon bone matrix after sequential chromatography on heparin-Sepharose, hydroxyapatite, and Sephacryl S-200 gel filtration columns. The remaining two defects were implanted with one disk of each hydroxyapatite preparation without osteogenin as control. Histomorphometry on decalcified sections prepared on days 30 and 90 showed superior osteogenesis in osteogenin-treated nonresorbable hydroxyapatite specimens as compared with controls. On day 90, substantial bone formation also had occurred in control nonresorbable hydroxyapatite specimens. On day 90, but not on day 30, significantly greater amounts of bone had formed in osteogenin-treated resorbable specimens as compared with resorbable controls. Overall, resorbable substrata performed poorly when compared with nonresorbable substrata, perhaps due to a premature dissolution of the implants. These results provide evidence that the biologic activity of osteogenin can be restored and delivered by a substratum other than the organic collagenous matrix, inducing rapid bone differentiation in calvarial defects of adult nonhuman primates. The adsorption strategy of osteogenin on porous inorganic nonimmunogenic substrata may help to design appropriate osteogenic delivery systems for craniofacial and orthopedic applications in humans.     

The breeding behavior and the behavior of larvae and juveniles of the sharksucker,Echeneis naucrates

Eleven sharksuckers,Echeneis naucrates, in the Oita Ecological Aquarium spawned from 2 June to 3 December 1974. The spawning behavior began as soon as the lights were turned off. Just before a female spawned, it was driven toward the surface of the water by a group of males. The spawned eggs were pelagic and 2.6 mm in diameter. Approximately 500 eggs were spawned each day. Seventy larvae were hatched on 15 July, and 26 of them were reared until 1 September. We observed the behavior of their larvae and juvenile stages, from the hatching to the attaching phases. The caudal fins of the larvae expanded as they grew. They swam near the bottom with their caudal fins folded. When the sucking disk began to form on the back of a larva’s pectoral fin, it stood still with its caudal fin bent on bottom. After the formation of the sucking disk, a larva would lie on its stomach or back. Some quickly-growing specimens began to stick to the walls, pipes, or plates when they attained 55 mm SL, 35 days after hatching.     

Relining of prosthesis with auto‐polymerizing hard denture reline resins: effect of post‐polymerization treatment on flexural strength

Background: It has been suggested that microwave irradiation and prosthesis immersion in hot water after its polymerization may improve mechanical and viscoelastic properties of acrylic resins. Purpose: This study was proposed to verify the influence of microwave post‐polymerization (PP) treatment over the flexural strength of thermo‐polymerizing acrylic resin specimens (QC‐20) relined or not with two different composition hard chairside auto‐polymerizing reliners [Kooliner (K) and New Truliner (NT)]. Materials and Methods: For this study, 50 specimens of 64 × 10 × 3.3 mm were polymerized and distributed into five groups. G1 (control) specimens without relining and PP; G2 specimens relined with K, without PP; G3 specimens relined with NT, without PP; G4 specimens relined with K, with PP (microwave irradiation with 650 W for 5 min); G5 specimens relined with NT, with PP. Tests were performed on a universal testing machine Instron 4411 with compression speed of 5 mm/min. Results: Specimens of K without PP did not show statistically different results (p < 0.05) when compared with control. However, when submitted to PP these specimens showed a significant increase in flexural strength. Specimens of NT showed the lowest flexural strength of all groups, with or without PP when compared with control and K groups. Conclusion: Microwave PP (650 W for 5 min) proved to be an effective method of improving the flexural strength of K relined prosthesis. However, it did not seem to affect NT specimens.     

Comparison of cervical disk implants and cervical disk fusion treatments in human cadaveric models

Articulating cervical disk implants have been proposed as an alternative to disk fusion in the treatment of cervical disk disease. To examine the mechanical effect of articulating cervical disk implants (ACDI) versus simulated cervical disk fusion, a mechanical test device was constructed and cadaveric tests were carried out. While results show little effect on the pressures above and below the treatment level, the percent hysteretic behavior of the specimens trended to be higher for the ACDI, indicating that these implants retain more of the natural energy absorption capability of the cervical spine.     

A New Drying Method of Plant Specimens for Scanning Electron Microscopy the t-Butyl Alcohol Freeze-Drying Method

The t-butyl alcohol freeze-drying method (lnoue and Osatake 1988) is a simple drying method of biological materials for scanning electron microscopy Fixed specimens were immersed in t-butyl alcohol after dehydration throgh a graded series of ethanol. Specimens in the alcohol were then forzen in a refrigerator. They were placed in the bell jar of a vacuum evaporator and simply evacuated with a rotary pump. The samples were completely dried within 40–60 min after the frozen alcohol was sublimated in the vacuum, when the specimen was examined by scanning electron microscopy (SEM), both surface and intracellular structures were demonstrated in three-dimension without any significant drying artifacts. Careful comparison of the results indicated that the SEM imayes obtained by this method were either superior or equal to those obtained by the critical point drying method.     

贵州省果树蹄蝠的分类记述

2008年10月在贵州省荔波县进行翼手目动物多样性调查中,于该县永康乡采集到2号蹄蝠标本,经与国内外记载过的蹄蝠科bicolor族群的标本进行比较,这2号标本的体型较小,前臂长分别为44.26mm、42.48mm,耳大而圆,耳长22.02mm、22.58mm;鼻叶简单,前鼻叶外侧没有小附叶,中鼻叶不发达;后鼻叶稍宽于前鼻叶和中鼻叶,被3纵隔分为4个部分,P2弱小,但未消失,位于齿列线外侧,这些特征与中国和泰国记载的果树蹄蝠Hipposideros pomona一致。另对贵州早期文献中记载的双色蹄蝠H.bicolor标本进行了查阅,认为其应归为果树蹄蝠。     

Preoperative dilatation of the cervix by single vaginal administration of 15-methyl-PGF2alpha-methyl ester.

Two different vaginal suppositories have been developed suitable for one single treatment for preoperative dilatation of the cervix prior to vacuum aspiration in late first trimester abortion. The study included 60 patients equally distributed in one control group (Group I) where vacuum aspiration was performed without pretreatment; one group (Group II) where the patients obtained 2.0 mg 15-methyl-PGF2alpha-methyl ester in a rapid releasing base six hours prior to operation and one group (Group III) where the prostaglandin dose was increased to 2.5 mg 15-methyl-PGF2alpha-methyl ester and a more slow releasing base was used and the operation performed after 12 hours. The mean cervical dilatation at operation was in Group II 9 mm and in Group III 11 mm in comparison with 4.8 mm in the control group. The bleeding at the operation was also significantly reduced.     

The occurrence of Chlamydia spp. in pigs with and without clinical disease

Background

Disk-associated cervical spondylomyelopathy (DA-CSM) is a multifactorial neurological disorder in which progressive caudal cervical spinal cord compression is mainly caused by one or more intervertebral disk protrusions. The Doberman pinscher breed seems predisposed for this condition. The underlying cause and pathophysiology of DA-CSM are currently unknown. Recently, wider intervertebral disks have been put forward as a risk factor for development of clinically relevant DA-CSM. However, little is known about other factors affecting intervertebral disk width. Therefore the aim of this study was to assess the association between intervertebral disk width, measured on magnetic resonance imaging (MRI), and clinical status, age, gender and intervertebral disk location in dogs with and without clinical signs of DA-CSM.

Methods

Doberman pinschers with clinical signs of DA-CSM (N=17),clinically normal Doberman pinschers (N=20), and clinically normal English Foxhounds (N=17), underwent MRI of the cervical vertebral column. On sagittal T2-weighted images, intervertebral disk width was measured from C2-C3 to C6-C7. Intra ?Cand interobserver agreement were assessed on a subset of 20 of the 54 imaging studies.

Results

Intervertebral disk width was not significantly different between Doberman pinschers with clinical signs of DA-CSM, clinically normal Doberman pinschers or clinically normal English Foxhounds (p=0.43). Intervertebral disk width was positively associated with increasing age (p=0.029). Each monthly increase in age resulted in an increase of disk width by 0.0057mm. Intervertebral disk width was not significantly affected by gender (p=0.056), but was significantly influenced by intervertebral disk location (p <0.0001). The assessed measurements were associated with a good intra ?Cand interobserver agreement.

Conclusions

The present study does not provide evidence that wider intervertebral disks are associated with clinical status in dogs with and without DA-CSM. Instead, it seems that cervical intervertebral disk width in dogs is positively associated with increase in age.     

Ethylenediaminetetraacetic Acid in Ammonium Hydroxide for Reducing Decalcification Time

Ethylenediaminetetraacetic acid (EDTA) solution is used to decalcify bone specimens for histological examination. Sodium hydroxide (NaOH) has been used to dissolve EDTA and to bring EDTA solutions to neutral pH. This solution, however, requires several weeks to decalcify bone specimens. We investigated a new de-calcification fluid using concentrated ammonium hydroxide (NH₄OH) to dissolve EDTA and to adjust the pH to neutral. Decalcification was performed using a magnetic stirrer with and without vacuum, or with a sonic cleaner. Decalcification end point was confirmed using both the weight loss and X-ray methods. After decalcification, specimens were processed through paraffin and sections were stained with hematoxylin and eosin. Decalcification employing NH₄OH required an average of six days. Light microscopy indicated good retention of cellular detail.     

VACUUM DRYING OF STEAM STERILIZED DRESSINGS

SUMMARY: The degree of vacuum and time of application needed to dry steam sterilized dressings has been investigated. If the steam supply is dry, and the pressure in the drying stage is reduced to an absolute pressure of 50 mm Hg, dressings will be cool and dry without holding the vacuum, provided they are not damp before sterilization.     

Structural characterization and reliable biomechanical assessment of integrative cartilage repair

Structural and functional characterization of integrative cartilage repair in controlled model systems can play a key role in the development of innovative strategies to improve the long-term outcome of many cartilage repair procedures. In this work, we first developed a method to reproducibly generate geometrically defined disk/ring cartilage composites and to remove outgrown fibrous layers which can encapsulate cartilaginous tissues during culture. We then used the model system to test the hypothesis that such fibrous layers lead to an overestimation of biomechanical parameters of integration at the disk/ring interface. Transmission electron microscopy images of the composites after 6 weeks of culture indicated that collagen fibrils in the fibrous tissue layer were well integrated into the collagen network of the cartilage disk and ring, whereas molecular bridging between opposing disk/ring cartilage surfaces was less pronounced and restricted to regions with narrow interfacial regions (< 2 microm). Stress-strain profiles generated from mechanical push-out tests for composites with the layers removed displayed a single and distinct peak, whereas profiles for composites with the layers left intact consisted of multiple superimposed peaks. As compared to composites with removed layers, composites with intact layers had significantly higher adhesive strengths (161+/-9 vs. 71+/-11 kPa) and adhesion energies (15.0+/-0.7 vs. 2.7+/-0.4 mJ/mm2). By combining structural and functional analyses, we demonstrated that the outgrowing tissue formed during in vitro culture of cartilaginous specimens should be eliminated in order to reliably quantify biomechanical parameters related to integrative cartilage repair.     

Microfiltration and ultrafiltration of polysaccharides produced by fermentation using a rotating disk dynamic filtration system

The recovery of exopolysaccharides (EPS) produced by Sinorhizobium meliloti bacteria by dynamic microfiltration was investigated using a rotating disk device designed in our laboratory, equipped with a 0.2 microm nylon membrane. This system differs from commercially available systems by the presence of vanes on the disk which produce a very important increase in permeate flux while yielding excellent EPS transmission. For polymers produced under standard fermentation conditions (70 h at 30 degrees C), the mass flux rose to 650 g h(-1) m(-2) using a disk equipped with 2 mm vanes rotating at 2000 rpm against 380 g h(-1) m(-2) with a smooth disk at the same speed. The maximum flux observed was 1560 g h(-1) m(-2) with a 6-mm vanes disk rotating at 3000 rpm and a 36 degrees C broth. An interesting finding was that the permeate flux J(f) for various disks can be correlated by the same function of the mean shear stress at the membrane tau(wm) according to J(f) = 4.6 tau(wm) (0.717) for a 30 degrees C broth, showing that the effect of vanes is merely to increase the shear stress by raising the fluid core velocity between the membrane and the disk. With 6-mm vanes the core angular velocity was found to be 84% of disk velocity vs. 45% for a smooth disk. When the fermentation temperature was increased to 36 degrees C to produce a lower molecular weight polymer, the permeate flux rose by about 250%, much more than what could be expected from the reduction in permeate viscosity and followed the same power law with membrane shear stress as for 30 degrees C. The same device was equipped with a PES 50 kDa membrane to concentrate EPS by ultrafiltration. Permeate fluxes were of the order of 160 L h(-1) m(-2) at 2000 rpm and 30 degrees C with nearly complete EPS rejection. Finally, the net electrical power consumed by the disk was measured by subtracting the power consumed without fluid from the power during filtration at the same speed. This power increases with speed and with the presence of vanes, but since the gain provided by the vanes is very high, the specific energy per m(3) of permeate is minimal with the highest vanes tested (6 mm) and maximal for smooth disks.     

Inter-electrode spacing of surface EMG sensors: reduction of crosstalk contamination during voluntary contractions

We investigated the influence of inter-electrode spacing on the degree of crosstalk contamination in surface electromyographic (sEMG) signals in the tibialis anterior (target muscle), generated by the triceps surae (crosstalk muscle), using bar and disk electrode arrays. The degree of crosstalk contamination was assessed for voluntary constant-force isometric contractions and for dynamic contractions during walking. Single-differential signals were acquired with inter-electrode spacing ranging from 5 mm to 40 mm. Additionally, double differential signals were acquired at 10 mm spacing using the bar electrode array. Crosstalk contamination at the target muscle was expressed as the ratio of the detected crosstalk signal to that of the target muscle signal. The crosstalk contamination ratio approached a mean of 50% for the 40 mm spacing for triceps surae muscle contractions at 80% MVC and tibialis anterior muscle contractions at 10% MVC. For single differential recordings, the minimum crosstalk contamination was obtained from the 10 mm spacing. The results showed no significant differences between the bar and disk electrode arrays. During walking, the crosstalk contamination on the tibialis anterior muscle reached levels of 23% for a commonly used 22 mm spacing single-differential disk sensor, 17% for a 10 mm spacing single-differential bar sensor, and 8% for a 10 mm double-differential bar sensor. For both studies the effect of electrode spacing on crosstalk contamination was statistically significant. Crosstalk contamination and inter-electrode spacing should therefore be a serious concern in gait studies when the sEMG signal is collected with single differential sensors. The contamination can distort the target muscle signal and mislead the interpretation of its activation timing and force magnitude.     

Preoperative dilatation of the cervix by single vaginal administration of 15-methyl-PGF2α-methyl ester

Two different vaginal suppositories have been developed suitable for one single treatment for preoperative dilatation of the cervix prior to vacuum aspiration in late first trimester abortion. The study included 60 patients equally distributed in one control group (Group I) where vacuum aspiration was performed without pretreatment; one group (Group II) where the patients obtained 2.0 mg 15-methyl-PGF_2α-methyl ester in a rapid releasing base six hours prior to operation and one group (Group III) where the prostaglandin dose was increased to 2.5 mg 15-methyl-PGF_2α-methyl ester and a more slow releasing base was used and the operation performed after 12 hours. The mean cervical dilatation at operation was in Group II 9 mm and in Group III 11 mm in comparison with 4.8 mm in the control group. The bleeding at the operation was also significantly reduced.     

Stain Solubilities Part III

Ethylenediaminetetraacetic acid (EDTA) solution is used to decalcify bone specimens for histological examination. Sodium hydroxide (NaOH) has been used to dissolve EDTA and to bring EDTA solutions to neutral pH. This solution, however, requires several weeks to decalcify bone specimens. We investigated a new de-calcification fluid using concentrated ammonium hydroxide (NH₄OH) to dissolve EDTA and to adjust the pH to neutral. Decalcification was performed using a magnetic stirrer with and without vacuum, or with a sonic cleaner. Decalcification end point was confirmed using both the weight loss and X-ray methods. After decalcification, specimens were processed through paraffin and sections were stained with hematoxylin and eosin. Decalcification employing NH₄OH required an average of six days. Light microscopy indicated good retention of cellular detail.     

Correlation of Matrix Metalloproteinases-1 and Tissue Inhibitor of Metalloproteinases-1 with Patient Age and Grade of Lumbar Disk Herniation

The authors studied the nuclear magnetic resonance films and the expression of MMP-1 and TIMP-1 in disk specimens’ of patients who had undergone operations for lumbar disk herniation. Forty-one lumbar disk patients were evaluated imaging for degenerative changes and their disk specimens immunohistochemical expression of MMP-1 and TIMP-1. The degree of degenerative changes was based on magnetic resonance imaging films. Sections of disk immunostained for MMP-1 and TIMP-1 were evaluated semiquantitatively. Patients were categorized in three age groups: <30 years, from 30 to 60 years, and >60 years of age. The expressions of MMP-1 and TIMP-1 were related to patients’ age and degree of degenerative changes. There were statistical differences in the expression of MMP-1 and TIMP-1 between the age and degree of degenerative changes groups. With the degree of degenerative changes, the expression of MMP-1 and TIMP-1 increased obviously. But in old age group, the expression of MMP-1/TIMP-1 was higher than the young groups. The expressions of MMP-1 and TIMP-1 were strongly correlated to the age and the degree of the degenerative changes. An important finding in this study is the unbalance of the expression of MMP-1 and TIMP-1 along with the growth of the age.     

Virtual slit scanning microscopy

We present a novel slit scanning confocal microscope with a CCD camera image sensor and a virtual slit aperture for descanning that can be adjusted during post-processing. A very efficient data structure and mathematical criteria for aligning the virtual aperture guarantee the ease of use. We further introduce a method to reduce the anisotropic lateral resolution of slit scanning microscopes. System performance is evaluated against a spinning disk confocal microscope on identical specimens. The virtual slit scanning microscope works as the spinning disk type and outperforms on thick specimens.