Application of B-flow imaging and its enhanced mode in perforator mapping

AIM

To explore the value of B-flow (B-mode blood flow) imaging and its enhanced mode in perforator mapping.

MATERIALS AND METHODS

Before surgery, B-flow imaging, enhanced B-flow imaging, colour Doppler flow imaging (CDFI), and contrast-enhanced ultrasound (CEUS) were used to detect the skin-perforating vessels and small vessels in the fat layer of the donor site. Taking the intra-operative results as the reference standard, the diagnostic consistency and efficiency of the four modes were compared. Statistical analysis was performed using the Friedman M-test, Cochran's Q-test, and the Z-test.

RESULTS

Thirty flaps were excised, with 34 skin-perforating vessels and 25 non-skin-perforating vessels, as confirmed during surgery. In order of the number of skin-perforating vessels detected, the results showed that enhanced B-flow imaging detected more vessels than B-flow imaging and CDFI (all p<0.05), CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05), B-flow imaging detected more vessels than CDFI (p<0.05). All four modes had remarkable and satisfactory diagnostic consistency and effectiveness, but B-flow imaging was the best (sensitivity 100%, specificity 92%, Youden index 0.92). In order of the number of small vessels in the fat layer detected, the results showed that enhanced B-flow imaging detected more vessels than CEUS, B-flow imaging, and CDFI (all p<0.05). CEUS detected more vessels than B-flow imaging and CDFI (all p<0.05).

CONCLUSION

B-flow imaging is an alternative method for perforator mapping. Enhanced B-flow imaging can reveal the microcirculation of flaps.

Clinical and biological implications of MYC activation: a common difference between MGUS and newly diagnosed multiple myeloma

Events mediating transformation from the pre-malignant monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) are unknown. We analyzed gene expression data sets generated on the Affymetrix U133 platform from 22 MGUS and 101 MM patients using gene-set enrichment analysis. Genes overexpressed in MM were enriched for cell cycle, proliferation and MYC activation gene sets. Upon dissecting the relationship between MYC and cell-cycle gene sets, we identified and validated an MYC activation signature dissociated from proliferation. Applying this signature, MYC is activated in 67% of myeloma, but not in MGUS. This was further confirmed by immunohistochemistry (IHC) using membrane CD138 and nuclear MYC double staining. We also showed that almost all tumors with RAS mutations expressed the MYC activation signature, and multiple mechanisms may be involved in activating MYC. MYC activation, whether assessed by gene-expression signature or IHC, is associated with hyperdiploid MM and shorter survival even in tumors that are not proliferative. Bortezomib treatment is able to overcome the survival disadvantage in patients with MYC activation.

The development of a rapid prototyping prosthetic socket coated with a resin layer for transtibial amputees

This article proposes a type of transtibial socket composed of an inner layer fabricated by a rapid prototyping (RP) machine and an outer layer coated with unsaturated polyester resin. This work integrates contemporary technologies including a handheld scanner and CAD systems, to design a thin primary socket shape and then manufactures the socket using a fused deposition-modeling machine. To prevent breakage caused by the layer-based forming process and to reinforce flexural strength, the current research coats the preliminary RP socket with a layer of unsaturated polyester resin. After shaping the proximal brim of the resin-reinforced RP socket to match the specific stump, this study assembles and aligns a shank and a prosthetic foot to form a prosthesis set. After completing a trial safety walk wearing the prosthesis, which is satisfactory to the amputee and a registered prosthetist, this research measures interface pressures between the stump and the resin-reinforced RP socket. Experiment results demonstrate that the resin-reinforced RP socket is applicable for transtibial amputees. In addition to strengthening the FDM socket and producing consistent socket fit, this study also demonstrates a feasible procedure that employs current technologies to design and manufacture transtibial sockets without plaster moulds.

Transformation of organic matter during co-composting of pig manure with sawdust

Co-composting of pig manure with sawdust was studied in order to characterize the organic transformation during the process, using both chemical and spectroscopic methods. Humic acids (HA) and fulvic acids (FA) were fractionated from immature and mature pig manure compost, and characterized. After 63 days of composting, the ratio of total organic carbon and soluble organic carbon decreased to a satisfactory low level and the solid and soluble C/N ratios decreased rapidly for the first 35 days before attaining a constant value, indicating compost maturity. Humification could be responsible for the increase in humic acid proportion during composting. The increase in the aromatic bonds after composting, as indicated by the reduction of C/H and C/O ratios of HA and FA, resulted in a more stabilized product. A substantial increase in high molecular weight compounds along with a small increase in low molecular weight compounds was found in mature compost. Moreover the HA also had more complex organic compounds at this stage. Fluorescence spectral analysis showed an increase in the maximum wavelength of HA associated with the contents of aromatic structures in solution. A decrease in relative absorbance of HA at 1160 cm(-1), 2950 cm(-1) and 2850 cm(-1) was seen in the FTIR spectra indicating the decomposition of complex organic constituents, into simpler ones. Increase in the aromatic compounds with higher stability could account for the relative increase in the absorbance of HA at 1650 cm(-1) and 1250 cm(-1) of the mature compost. The composition of FA was not much altered, indicating most of the degradation of organic matter occurred in HA. Data from organic carbon, C/N ratio, elemental analysis, E(4)/E(6) ratio, gel chromatography, fluorescence and FTIR spectra indicated an increase in polycondensed structures and the presence of more stable organic matter in the mature compost.

Effect of C/N on composting of pig manure with sawdust

The aim of this composting trial was to evaluate the effect of C/N on the composting process of pig manure with the purpose of reducing the amount of sawdust normally used as co-composting materials. Two aerobic static piles were prepared consisting of pig manure mixed with sawdust at an initial C/N of 30 (pile A) and 15 (pile B), respectively. Pile B containing larger amount of pig manure showed a slower rise in temperature, lower maximum temperature, and shorter thermophilic phase than pile A. It also resulted in higher pH and electrical conductivity (EC) values, and even higher contents of soluble NH4-N and volatile solids throughout the composting period. Chemical and biological parameters including dissolved organic carbon (DOC) (4932 mg kg(-1)), soluble NH4-N (371 mg kg(-1)), C/Nsolid (18.3), C/Naquoeus (5.8) and seed germination index (GI) (66.5%) indicated that pile A achieved maturity after 49 days of composting. After 63 days of composting, pile B contained 5352 and 912 mg kg(-1) of DOC and soluble NH4-N content, respectively, which was much higher than the criterion of 5% and 400 mg kg(-1), indicating its immature nature. Pile B showed a relatively low GI value of 46%, which may be due to its high indigenous EC value as a result of larger amount of pig manure. Therefore, co-composting of pig manure with sawdust at a low initial C/N would require a composting longer than 63 days, and, the high salinity due to the large amount of pig manure would pose a potential inhibition on plant growth.

Elbow load with various forearm positions during one-handed pushup exercise

This is the first study of the one-handed pushup, and tries to show the effects of forearm rotations. Previous studies of elbow loading have focused on passive loading and small loads, because data from large loads during active exercise is not easy to obtain. In order to investigate the biomechanical impact of hand position on the elbow and the potential trauma mechanisms of outstretched elbow, joint loading across the elbow was analyzed for three forearm rotational positions, neutral, 90 degrees internal rotation and 90 degrees external rotation. Both kinematic and kinetic data were collected from eight volunteers by the Motion Analysis System and a Kistler Force Plate. Statistical analysis of the data delineates the relationship between elbow joint load and hand rotational position during one-handed pushup, and also provides useful biomechanical information for this challenging exercise. The axial and valgus stresses and forces are the major concerns. The peak axial forces exerted on the elbow joint averaged 65 % of the body weight when the hand position was neutral, and was significantly reduced with the hand rotated either internally or externally. The peak valgus shear force with the hand externally rotated was 50 % greater than the other two positions. Thus, outward rotation of the hand is a stressful position that should be avoided during one-handed pushup exercise or forward falls with outstretched hands in order to reduce the risk of elbow injuries.

An in vitro study on restoring bond strength of a GIC to saliva contaminated enamel under unrinse condition

OBJECTIVES

This study attempted to find a method of restoring the tensile bond strength of glass ionomer cement (GIC) to saliva contaminated enamel under unrinse condition.

METHODS

One hundred and thirty human non-carious permanent teeth were divided into two major groups. Either treatment with air drying, acetone, polyacrylic acid, maleic acid, tartaric acid, Scotchbond primer or no treatment at all was applied to both clean and saliva contaminated enamel surfaces prior to GIC placement. Samples were debonded in tension after 7 days of storage in water using a universal testing machine. Statistical analysis was performed using one-way ANOVA, Tukey's studentized range test and Wilcoxon's rank sums test to determine the significance of the difference of tensile bond strengths within and between the two major groups.

RESULTS

Bond strength of GIC to clean enamel was 2.46+/-0.79 MPa while the bond strength of GIC to wet contaminated enamel was significantly reduced to 1.28+/-0.32 MPa (p<0.01). However, the bond strengths were restored when the contaminated enamel surfaces were air-dried (2.19+/-0.38 MPa) or applied with either maleic acid (2.80+/-0.63 MPa) or Scotchbond primer (2.13+/-0.65 MPa) before placing GIC over the enamels.

CONCLUSIONS

Air drying, or application of maleic acid or Scotchbond primer to the contaminated enamel without rinsing prior to GIC placement can restore the tensile bond strength to a level similar to that of non-contaminated control.

Effect of elbow flexion on upper extremity impact forces during a fall

OBJECTIVE

The overall objectives are to develop a biomechanical model for a simulated fall with outstretched hand.

DESIGN

Cross-sectional study involving young healthy volunteers in a university research laboratory setting.

BACKGROUND

Little is known about the factors which influence fracture risk during a fall on outstretched hand.

METHODS

A group of 11 male subjects volunteered for this investigation. A set of eight reflective markers was placed bilaterally on selected anatomic landmarks. Subjects were suspended with both elbows extended and wrists dorsiflexed, preparing to impact the ground and force plates from two different fall heights: 3 and 6 cm. Two different postures for the elbows were employed. In the elbow extension experiment, the elbows were extended at all times. In the elbow flexion experiment, the elbows were extended at impact, but then flexed immediately, as though in the initial downward phase of a push-up exercise.

RESULT

Increasing the fall height significantly increased the upper extremity axial forces by 10% and 5%. No significantly different differences were found in the axial forces applied to the wrist, elbow or shoulder between the elbow flexion and elbow extension trials, but the elbow mediolateral shear force was 68% larger (P=0.002) in the extension trials.

CONCLUSIONS

Performing an elbow flexion movement at impact reduces the first peak impact force value and postpones the maximum peak value. Although changing the fall arrest strategy from elbow extension to elbow flexion did not affect the peak impact force on the hand, it did require substantially greater elbow and shoulder muscle strengths.

RELEVANCE

This paper yields insights into how the physical demands of arresting mild falls may relate to upper extremity muscle capacity, joint dislocation and bony fracture.

Nitrogen transformations during pig manure composting

Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co-composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total-N, soluble NH4-N, soluble NO3-N and soluble organic-N. The total-N increased after 63 days of composting, as well as the soluble NO3-N and soluble organic-N. Soluble NH4-N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co-composting of pig manure with sawdust reached maturity after 49 days of composting, while co-composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH4-N was significantly negatively (P < 0.05), while soluble NO3-N and soluble organic-N were significantly positively (P < 0.05), correlated with seed germination index (GI). Addition of leaves in co-composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.

Co-composting of pig manure with leaves

The increase in the market price of sawdust makes it a less attractive bulking agent for pig manure composting. Hence, it was the aim of this project to evaluate the feasibility of co-composting pig manure with leaves with special emphasis on its effects on compost maturity and quality. Two piles were prepared with one pile (Pile A) just constituted of pig manureand sawdust at a mixing ratio of 3:2 (w/w, fresh weight), while the other one (Pile B) with pig manure, sawdust and leaves at 3:1:1 ratio (w/w, fresh weight) to achieve a C/N ratio of 30. Each 8 m3 heap was turned and mixed every 3 days to provide sufficient aeration and the moisture content was kept at 60-70% (w/w) throughout the composting period. After 49 days of composting, dissolved organic carbon (DOC), soluble NH4-N(solid), C/N(aqueous) and C/N(aqueous) of pile A decreased to <5%, 400 mgkg(-1), 20 and 6, respectively, indicating a high degree of maturity, while pile B with leaves required only 35days. Seed germination index (GI) of pile A increased to 66.5% at day 49, while pile B to 52.4% at day 35, which was higher than the phytotoxin-free level of 50% recommended for agricultural use. This demonstrated that the addition of leaves enhanced the humification process and shortened the time required for maturation and stabilization of pig manure composting. Therefore, it is recommended to co-compost pig manure with leaves to provide a means to reutilize this waste and in the same time to reduce the dependence on sawdust as a buLking agent.

The relationship between radiologic interpretation and root tip fracture during tooth extraction performed by junior clinicians

OBJECTIVES

The purpose of this study was to analyze the relationship between root tip fracture and radiologic interpretation of root morphology on periapical radiographs during third molar extraction performed by junior clinicians.

METHODS

Before tooth extraction, periapical radiographs of 107 patients with 116 third molars were evaluated by junior clinicians, all with less than 5 years of clinical experience. Radiologic interpretations of root morphology-including number, curvature, fusion, and accessory root-were recorded before each extraction. The clinicians were also asked to estimate the possibility of root fracture on a Visual Analogue Scale before the procedure. The exact morphology of the extracted teeth was recorded after the extraction for the purpose of comparison.

RESULTS

Twenty-nine of 116 teeth extracted were not correctly interpreted in at least 1 of the morphologic categories surveyed. The average expected fracture rate of nonfractured teeth was 23.1%, whereas the average expected fracture rate of fractured teeth was a significantly higher 50.3%. Misinterpretation of root morphology on radiographs decreased with increased clinical experience. Senior residents had the lowest misinterpretation and fracture rate. Logistic regression analysis showed that fracture is most closely related to the estimated fracture rate (4.95) and is also significantly related to underestimation of root curvature (0.95; 24.56 with 2 df of chi-square, P = .0001).

CONCLUSIONS

Misinterpretation of root morphology on radiographs occurred in 25% of the teeth. Root curvature was the most misinterpreted item studied. Fracture was most closely related to the estimated fracture rate. Junior clinicians in this study expected that only 50% of the fractured teeth would fracture, reflecting a general underestimation of root tip fracture. Further study should be performed to evaluate how to increase the accuracy of root curvature interpretation.

Uncharged thioflavin-T derivatives bind to amyloid-beta protein with high affinity and readily enter the brain

In vivo assessment of the beta-sheet proteins deposited in amyloid plaques (A beta peptide) or neurofibrillary tangles (tau protein) presents a target for the development of biological markers for Alzheimer's disease (AD). In an effort to develop in vivo beta-sheet imaging probes, derivatives of thioflavin-T (ThT) were synthesized and evaluated. These compounds lack the positively charged quaternary heterocyclic nitrogen of ThT and are therefore uncharged at physiological pH. They are 600-fold more lipophilic than ThT. These ThT derivatives bind to A beta(1-40) fibrils with higher affinity (Ki = 20.2 nM) than ThT (Ki = 890 nM). The uncharged ThT derivatives stained both plaques and neurofibrillary tangles in post-mortem AD brain, showing some preference for plaque staining. A carbon-11 labeled compound, [N-methyl-11C]6-Me-BTA-1, was prepared, and its brain entry and clearance were studied in Swiss-Webster mice. This compound entered the brain at levels comparable to commonly used neuroreceptor imaging agents (0.223 %ID-kg/g or 7.61 %ID/g at 2 min post-injection) and showed good clearance of free and non-specifically bound radioactivity in normal rodent brain tissue (brain clearance t(1,2) = 20 min). The combination of relatively high affinity for amyloid, specificity for staining plaques and neurofibrillary tangles in post-mortem AD brain, and good brain entry and clearance makes [N-methyl-11C]6-Me-BTA-1 a promising candidate as an in vivo positron emission tomography (PET) beta-sheet imaging agent.

Enhanced photo--catalytic activity of gold ion and gold modified

The gold ion modified TiO2 was prepared by means of sol-gel whereas gold deposited TiO2 was prepared by means of photo-reduction. The physical properties were influenced significantly by the presence of gold ion or gold. The enhanced photo-activity of gold modified TiO2 was quantified in terms of methylene blue degradation. The presence of gold ion in TiO2 lattices or gold on TiO2 surface enhanced their photo-activity. The optimum molar content of gold ion doping and gold deposition all was 0.5%. The first-order rates constants of gold modified TiO2 was more than that of pure TiO2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO2 lattices was more effective to enhance the photo-activity than gold on TiO2 surface. Moreover, the relationship between physical properties, chemical properties and photo-activity has been discussed.

Synergistic effect of Nd:YAG laser combined with fluoride varnish on inhibition of caries formation in dental pits and fissures in vitro

BACKGROUND AND PURPOSE

Although the effectiveness of neodymium yttrium aluminum garnet (Nd:YAG) laser and fluoride anticaries treatment has been established, most previous studies focused on smooth tooth surfaces. We evaluated the anticaries effects of Nd:YAG laser combined with fluoride varnish (Duraphat) on caries-susceptible pit and fissure areas.

METHODS

A total of 36 noncarious molars were treated with either a Nd:YAG laser (2.5 W, 6 sec) followed by fluoride varnish, Nd:YAG laser only, fluoride varnish only, or no treatment (control). Artificial carious lesions were created to assess the acid resistance of enamel after treatment. Undecalcified successive tooth slices were made. Percentage lesion formation, lesion length, and lesion depth were evaluated using polarized light microscopy.

RESULTS

The Nd:YAG laser enhanced the resistance of dental enamel to acid challenge. However, Nd:YAG laser alone was not as effective as the Nd:YAG laser combined with fluoride varnish, especially for the treatment of pits and fissures. Nd:YAG laser treatment combined with fluoride varnish inhibited 43% of lesions at pits and fissures and 80% of lesions on smooth surfaces compared to no treatment. Carious lesions had shallower depth and shorter length. No carious lesion extended beyond the dentinoenamel junction in either laser-treatment group.

CONCLUSIONS

A synergistic effect on dental caries prevention in pit and fissure areas and on the smooth surfaces of the tooth can be achieved by applying Nd:YAG laser followed by fluoride varnish.

TiO2-assisted photo-catalysis degradation process of dye chemicals

The photo-catalytic degradation pathway and degradation products of methylene blue, rhodamine B, methyl orange, and malachite green in aqueous TiO2 suspension irradiated by high pressure mercury lamp by means of UV-visible absorption spectra and ion chromatography were investigated. The photo-catalysis degradation of dye solutions with charges was greatly effected by pH value owing to the electrostatic model. The photo-degradation rate of dyes anion increased with the decrease of pH value, in contrast, the photo-degradation rate of dyes cation increased with the increase of pH value. And the absorption peaks diminished with a blue shift. After illuminated for 30 minutes, a part of dye chemicals were completely mineralized and transferred into inorganic species including chloride ion, ammonium ion, nitrate ion, sulfate ion. And the addition of 100 mmol/L H2O2 promoted the formation of inorganic species. In this study, the quantity of ammonium ion was much more than that of nitrate ion. That indicated the formation of nitrate is from ammonium. The purification rate of COD in four kinds of dye solution was 71.7%-88.7%. The decrease of COD of dyes solution implies the feasibility of the environmental application of photo-catalyzed process.

Gait analysis and energy consumption of below-knee amputees wearing three different prosthetic feet

This study scientifically measures the dynamic gait characteristics and energy consumption of 16 male below-knee amputees, eight vascular and eight traumatic, while wearing solid ankle cushion heel (SACH), single axis and multiple axis prosthetic feet via six-camera motion analysis, metabolic measurement cart and heavy-duty treadmill. Subjective results are additionally determined via questionnaire after testing. Motion analysis showed statistically significant differences at P<0.05 between the SACH, single axis and multiple axis foot in the velocity, cadence, stride length and single limb stance. Significant differences were found in energy consumption between the traumatic and vascular groups, and significant changes in walking under different speeds and different inclines. Results provide quantitative and qualitative information about the dynamic performance of the various feet, which can be helpful in prescribing the optimal prosthetic foot for individual amputees.

Resting dental plaque pH values after repeated measurements at different sites in the oral cavity

Plaque pH measurements can be used to detect individual's caries susceptibility and the cariogenic potential of ingested foods. However, repeated measurements with a touch electrode at a single site may affect the metabolic state of the dental plaque and result in changes of its inherent pH values. The purposes of this study were to evaluate the influence of repeated measurements of resting plaque pH values and to determine the pH values at different interdental sites. Eleven dental students participated in the study. The dental plaque was built up after thorough oral hygiene care. The subjects were then instructed to maintain a normal diet but to refrain from any oral hygiene care for the next 48 hours. Measurement of plaque pH was performed with an antimony electrode at 6 interproximal sites, including central spaces between the upper and between the lower central incisors, and the area between the second premolar and the first molar in each quadrant. At each tested site, measurements were taken 5 times at 0, 10, 30, 45 and 60 min. The results showed that the plaque pH became slightly alkaline at all the tested locations after repeated measurements. However, only the lower incisor area showed a significant change in pH values. Interdental plaque on the lower arch showed higher pH values than did that on the upper arch. There was no significant difference between the pH values on the right and left corresponding sites as determined using the Wilcoxon signed ranks test.

Nanospheres of biodegradable polymers: a system for clinical administration of an anticancer drug paclitaxel (Taxol)

INTRODUCTION

Paclitaxel is a natural antineoplastic drug. It has been approved by the Food and Drug Administration (FDA) for the treatment of various cancers, especially ovarian and breast cancers with the best effect over other anticancer agents. Due to its high hydrophobicity however, an excipient such as Cremophor EL has to be used, which causes additional serious side effects. This study was intended to investigate the feasibility to apply nanospheres of biodegradable polymers as an alternative system to achieve best results with least side effects.

MATERIALS AND METHODS

FDA-approved biodegradable polymers such as poly(D, L-lactic-co-glycolic acid) (PLGA) and poly(D, L-lactic acid) (PLA) were used to fabricate paclitaxel-loaded nanospheres by the solvent extraction/evaporation technique. The nanospheres fabricated in various conditions were characterised by laser light scattering for size and size distribution, scanning electron microscopy (SEM) and atomic force microscopy (AFM) for surface morphology, X-ray photoelectron spectroscopy (XPS) for the chemical structure of the surface. The drug encapsulation efficiency (EE) and the in vitro release kinetics were measured by HPLC.

RESULTS

The products ranged from 300 nm to 700 nm with low polydispersity. The in vitro drug release can last more than 6 months at an approximately constant rate after an initial burst. The release kinetics can be fully controlled by the material used and the fabrication conditions.

CONCLUSIONS

Nanospheres of biodegradable polymers can be an ideal carrier for pacitaxel to eliminate the side effects caused by the excipient currently used in clinical administration. The technique developed can also be applied to other anticancer drugs.

Prevalence and treatment costs of infant caries in Northern California

To determine the prevalence of infant caries in low-socioeconomic-status children and to analyze the costs of their treatment, we retrospectively evaluated 357 children, ages eight months to seven years, who were treated during 1992 at a university-associated medical center in Northern California. Infant caries was diagnosed by several different standards, and prevalence varied according to the diagnostic criteria employed: 27 percent by the presence of any labiolingual lesion on the maxillary incisors; 32 percent by the presence of at least two carious maxillary incisors; 27 percent by the presence of at least three carious maxillary incisors; and 36 percent by a dmft > or = 5. Prevalence was higher among boys than girls (37 percent versus 27 percent), and highest in the group ages 3-4 years (43 percent). The cost of dental treatment increased with deft and ranged from $408 for deft 2-5 to $1725 for deft 16-20. Many patients failed to comply with recommended treatment for reasons of cost. Our results showed that (1) the prevalence of infant caries varies depending upon the clinical criteria used for diagnosis; (2) the cost of rehabilitating primary dentition increases in proportion to the number of teeth involved; and (3) low-income patients avoid treatment of infant caries for a variety of reasons related to the cost involved.

Nasopharyngoscopic evaluation and cephalometric analysis of velopharynx in normal and cleft palate patients

The velopharyngeal dimensions and velopharyngeal functions of 58 patients having a cleft lip and palate were compared with those of 30 normal noncleft subjects. The patient group received perceptual speech assessment, nasopharyngoscopic examination, and lateral cephalogram, and was classified accordingly into three categories: velopharyngeal competency, borderline velopharyngeal competency, and velopharyngeal incompetency. The results indicated that (1) the need ratio differs significantly among the three cleft palate patient groups and (2) when compared to the control group, the velopharyngeal incompetency group has an excessive need ratio, narrower posterior pharyngeal wall, narrower linear dimensions in pharyngeal depth, and shorter velar and hard-palate length. The clinical implication and application of the findings are discussed.

Changes of dentinal tubules following fluoride iontophoresis

Fluoride(F) iontophoresis is preferred over topical application to provide long lasting dentin desensitization. The purpose of this study was to evaluate the changes in dentinal tubules following fluoride iontophoresis under SEM observation. Teeth were divided mainly into 3 groups: controls, NaF treated teeth with iontophoresis and those without inotophoresis. A battery operated device was used to apply electric current to teeth. All the teeth were prepared for scanning electron microscopy after treatments. Fluoride treatment, either non-iontophoretic or iontophoretic, produced granular precipitation in dentinal tubules and reduced tubular diameter. In 5-minute non-iontophoretic NaF treated teeth, the depth of precipitate penetration was 75 microns on average where the granules were small and sparse. In the 5-minute iontophoretic NaF treated teeth, the average penetration of precipitation reached 250 microns in one application whereas in three applications to teeth the average depth of penetration reached 830 microns. Fluoride iontophoresis resulted in obstruction of dentinal tubules. Both the frequency and duration od treatment under constant current and voltage affected the size of particles, the form of precipitation and the depth of penetration. Larger particle size and deeper fluoride penetration were observed in iontophoresis treated teeth compared to non-iontophoresis treated teeth. Therefore, repeated fluoride iontophoresis treatment is suggested to ensure long lasting densensitization effects.

The parabrachial area: electrophysiological evidence for an involvement in visceral nociceptive processes

1. Neurons (n = 142) were recorded with extracellular micropipettes in the parabrachial (PB) area, in the anesthetized rat, some of them being antidromically driven from the centralis nucleus of the amygdala (Ce). The spontaneous activity of these neurons was low, (10th percentile < median frequency < 90th percentile; 0.01 < 0.3 < 11 Hz), and the activity of a very high proportion of the PB neurons (89%, 127/142) were affected by mechanical or thermal cutaneous stimuli almost exclusively in the noxious range; most of them were activated and received inputs from A delta and/or C fibers. 2. A majority of the PB neurons (66%, 93/142) were affected by visceral stimuli (bradykinin intraperitoneal and/or colorectal distension), almost exclusively in the noxious range; all of them (except one) were also affected by cutaneous noxious stimuli. The remaining neurons not affected by these visceral stimuli were only activated by cutaneous noxious stimuli (n = 35) or completely unresponsive (n = 14; i.e., only 10% of the whole population). 3. Thirty-five percent (49/142) of the whole population of PB neurons responded to bradykinin intraperitoneal and/or to strong colorectal distension with an intense and sustained increase of discharge. The response to bradykinin and to colorectal distension was often dissociated, i.e., the activation was often produced by only one of the stimuli the other being ineffective or inhibitory. The intensity of responses to visceral noxious stimuli was between 5-45 Hz with a mean value of 20 +/- 2 (SE) Hz (n = 49). The visceral activated neurons exhibited a clear capacity to encode the colorectal distension in noxious range: 1) the stimulus-response function was almost always positive and monotonic; 2) as for the individual curves, the slope of the mean curve progressively increased up to the highest interval of pressure tested (100-125 mmHg); and 3) the threshold for neuronal response to colorectal distension was between 25-100 mmHg with a mean pressure threshold of 56 +/- 24 (SD) mmHg (n = 19). Viscerosomatic convergence was observed for 84% of these neurons: they were also activated by thermal and/or mechanical cutaneous noxious stimuli while only 16% of them were activated only by visceral noxious stimulation. 4. Thirty-one percent (44/142) of the whole population of PB neurons were inhibited by both strong colorectal distension and intraperitoneal bradykinin (82%) or only by one of the stimuli being unresponsive to the other (18%).(ABSTRACT TRUNCATED AT 400 WORDS)

Intravenous morphine depresses the transmission of noxious messages to the nucleus centralis of the amygdala

It has recently been demonstrated that the nucleus centralis of the amygdala contains numerous neurons specifically driven by noxious stimuli. The aim of the present study was to investigate the effect of i.v. morphine on responses of neurons located in the nucleus centralis of the amygdala to noxious mechanical or thermal stimuli. It was observed, in halothane-anesthetized rats, that i.v. morphine caused a marked depression of responses induced by noxious thermal (waterbath, 50 degrees C) and mechanical (pinch) stimuli and caused a moderate depression of spontaneous activity in a dose-related (1, 3, 9 mg/kg) and naloxone reversible fashion. The ED50 value was 1.2 and 9 mg/kg for i.v. morphine for the evoked activity and spontaneous activity, respectively. The strong depressive effect of morphine on evoked activity probably reflects a direct action of this drug at both spinal and parabrachial levels. These results could account, at least in part, for the effect of morphine on the emotional-affective aspects of pain.

Morphine depresses the transmission of noxious messages in the spino(trigemino)-ponto-amygdaloid pathway

We had recently demonstrated that a subregion of the parabrachial area relays nociceptive information in the spino(trigemino)-ponto-amygdaloid pathway. The aim of the present study was to investigate, in halothane-anesthetized rats, the effect of i.v. administration of morphine on nociceptive specific neurons located in the parabrachial area with some cells being antidromically driven from the amygdala. Morphine induced a marked depression of responses elicited by noxious thermal stimuli (waterbath, 50 degrees C) dose relatedly (1, 3, 9 mg/kg) and naloxone reversibly, with an ED50 = 1.8 mg/kg. This effect of morphine probably not only reflects the direct action of this drug at the spinal level, but could also involve a direct action at the parabrachial level. These results could account at least in part for the effect of morphine on the emotional-affective aspects of pain.

Nucleus centralis of the amygdala and the globus pallidus ventralis: electrophysiological evidence for an involvement in pain processes

1. Neurons (n = 177) were recorded with extracellular micropipettes in and around the nucleus centralis of the amygdala (Ce), in anesthetized rats. The spontaneous activity of these neurons was variable (0.25 less than 3 less than 35 Hz, n = 175; 10th percentile less than median less than 90th percentile). A majority (80%) of these neurons were excited or inhibited exclusively or preferentially by noxious stimuli. These units were separated into two groups: 1) a group of neurons excited by noxious stimuli (46% of the whole population) and 2) a group of neurons inhibited by noxious stimuli (34% of the whole population). 2. The receptive fields of both groups of neurons were very large: in about one-half the cases the neurons responded similarly from all parts of the body, and in the other cases the responses were greater when the stimuli were applied to a restricted part of the body. 3. Seventy-seven percent of the excited neurons had responses of relatively high magnitudes. In this group, most cells (75%) were exclusively driven by noxious stimuli; the others (25%) were preferentially activated by noxious stimuli. These neurons responded to mechanical (pinch or squeeze) and/or thermal (water bath or water jet greater than 44 degrees C) noxious stimuli with a marked and sustained activation. 4. Sixty percent of the inhibited neurons had a marked decrease of activity in response to noxious stimuli. In this group, most of them (81%) were exclusively inhibited by noxious stimuli, whereas the remainder (19%) were preferentially inhibited by noxious stimuli. These neurons responded to mechanical (pinch or squeeze) and/or thermal (water bath or waterjet greater than 44 degrees C) noxious stimuli with a suppression or a marked and sustained decrease in activity. 5. All of the nociceptive neurons responded to intense transcutaneous electrical stimulation with one or several components of activation or inhibition. According to their latencies, three types of components were distinguished: early, intermediate, and late components. We estimate that the early and the intermediate components would be triggered by the activity of peripheral fibers in the 6- to 20-m/s range and therefore could be in the A delta fibers range, whereas the late component would be triggered by fibers in the 0.5- to 1-m/s range and therefore could be in the C fibers range. 6. The neurons excited or inhibited by noxious stimuli were not homogeneously distributed in and around the Ce.(ABSTRACT TRUNCATED AT 400 WORDS)

[Treatment of severe electrical burn of the skull]

From Jan. 1970 to Feb. 1989, 10 cases of severe electrical burns of the skull were treated. There were necroses of the full skull bone layer and skin in 4 cases and necroses of the skull skin and external skull bone layer in 6 cases. Cure in 8 cases and death in 2 cases. The authors consider that in the early-stage protecting and reserving the skull intact is important. Repairing wound with full-circulatory skin flap or myocutaneous flap is a reasonable selection. In the later-stage, the wound may be repaired with skin graft on the granulating wound after removing the necrotic bone.

Antiviral, antimetabolic, and cytotoxic activities of 5-substituted 2'-deoxycytidines

Various 5-substituted 2'-deoxycytidines, including 5-bromo-dCyd, 5-iodo-dCyd, 5-nitro-dCyd, 5-ethynyl-dCyd, 5-propyl-dCyd, (E)-5-(2-bromovinyl)-dCyd, and (E)-5-(2-iodovinyl)-dCyd, were evaluated for their antiviral and antimetabolic properties in primary rabbit kidney (PRK) cell cultures and for their inhibitory effects on murine L1210 cell proliferation. All dCyd analogues proved to be selective inhibitors of herpes simplex virus (HSV) replication: 5-bromo-dCyd, 5-iodo-dCyd, 5-nitro-dCyd, and 5-ethynyl-dCyd were more selective in their anti-HSV activity than were the corresponding 5-substituted 2'-deoxyuridines, whereas 5-propyl-dCyd, (E)-5-(2-bromovinyl)-dCyd, and (E)-5-(2-iodovinyl)-dCyd were as selective as their dUrd counterparts. The dCyd analogues were also less cytotoxic (for both PRK and L1210 cells), as could be monitored by inhibition of either cell proliferation or host-cell DNA synthesis (incorporation of radiolabeled precursors). Of all 5-substituted 2'-deoxycytidines tested, the (E)-5-(2-halogenovinyl) derivatives emerged as the most potent and most selective inhibitors of HSV (Type 1) replication.

Mutagenicity of N-alkyl-N-(alpha-acetoxyalkyl) nitrosamines in V79 Chinese hamster cells in relation to alkylating activity

Mutation to ouabain resistance and cytotoxicity were tested in V79 Chinese hamster cells after the cells had been treated for 2.5 hr with a series of N,N-dialkylnitrosamines (alkyl=methyl, ethyl, propyl, butyl or tert-butyl) monosubstituted at the alpha-carbon with an acetoxy group. The effects of the length of alkyl chain and the mode of substitution with the acetoxy group on the cytotoxicity and mutagenicity were examined. In the series of N-alkyl-N-(acetoxy-methyl) nitrosamines with an acetoxy group at the primary alpha-carbon, the methylating compound N-methyl-N-(acetoxymethyl) nitrosamine was the most cytotoxic and mutagenic, and the biological activities decreased in the order of ethyl, butyl and propyl homologs. N-tert-Butyl-N-(acetoxymethyl) nitrosamine was not mutagenic at the concentration tested. At equitoxic concentrations, N-ethyl-N-(acetoxymethyl) nitrosamine was found to be the most mutagenic. Of the two N-alkyl-N-(alpha-acetoxybutyl) nitrosamines having an acetoxy group at the secondary alpha-carbon, N-methyl-N-(alpha-acetoxybutyl) nitrosamine was more cytotoxic and mutagenic than N-butyl-N-(alpha acetoxybutyl) nitrosamine. A comparison of the corresponding N-alkyl-N-(acetoxymethyl) nitrosamines and N-alkyl-N-(alpha-acetoxybutyl) nitrosamines showed that the latter had stronger activities. A plot of the mutation frequency versus the ability of the alpha-acetoxy compounds to alkylate 4-(p-nitrobenzyl) pyridine was linear. This indicates that the chemical reactivity of the compounds plays an important role in inducing mutation in V79 Chinese hamster cells.

Synthesis and antiviral activity of 5-[(cyanomethylene)oxy]-2'-deoxyuridine

To study the influence of substitution of CN for C identical to CH in the anti-herpes virus nucleoside 5-(propynyloxy)-2'-deoxyuridine (1), 5-[(cyanomethylene)oxy]-2'-deoxyuridine (2) was prepared. When the potassium salt of 5-hydroxy-2'-deoxyuridine was reacted with iodoacetonitrile in dry DMF, the bisalkylated product 3-(cyanomethyl)-5-[(cyanomethylene)oxy]-2'-deoxyuridine (3) was the major product with a lesser amount of 3-(cyanomethyl)-5-hydroxy-2'-deoxyuridine (5) and only a trace amount of the desired product (2). In contrast, when 5-hydroxy-2'-deoxyuridine was alkylated in water in the presence of 1 equiv of KOH, compound 2 was the major product. In cultures of primary rabbit kidney (PRK) cells, compound 2 showed an anti-herpes virus activity that was comparable to that of 1 and ara-A. Compound 2 did not inhibit incorporation of [Me-3H]dThd or [1',2'-3H]dUrd into DNA of PRK cells; however, its anti-herpes virus activity was completely prevented upon the addition of either dThd or dUrd.

Interferon induction by mismatched analogues of polyinosinic acid . polycytidylic acid [(Ix,U)n.(C)n]

Interruption of the (I)n strand of (I)n.(C)n by unpaired bases [(U)] yielded mismatched analogues, (Ix,U)n.(C)n which were still effective as inducers of interferon, provided the I:U ratio (x) was equal or greater than 10. In highly sensitive interferon-induction systems such as primary rabbit kidney cells and human skin fibroblasts superinduced with cycloheximide and actinomycin D, (I10,U)n.(C)n and (I50,U)n.(C)n proved nearly as active as (I)n.(C)n. By virtue of their increased susceptibility to degradation by nucleases, (Ix,U)n.(C)n complexes with 10 less than or equal to x less than or equal to 50 may be expected not to persist as long in biological fluids as (I)n.(C)n, hence to induce fewer side effects.

Carcinogenicity and mutagenicity of 4-nitropyridine 1-oxide derivatives

Carcinogenicity and mutagenicity of 4-nitropyridine 1-oxide (4-NPO) and 7 kinds of its alkyl derivatives were tested on mice and on Salmonella typhimurium strains and Escherichia coli strains. 3-Methyl-4-NPO is the most potent carcinogen, followed by 3-ethyl-4-NPO and then 4-NPO. Mutagenicity was most potent in 3-methyl, 2,3-dimethyl, and 2,5-dimethyl derivatives, moderate in 4-NPO and 2-methyl and 2,6-dimethyl derivatives, and to a least extent in 3,5-dimethyl-4-NPO. Structure-mutagenicity relationship was discussed on the basis of molecular mechanism of the carcinogenesis of 4-nitroquinoline 1-oxide. Quantitative relationship between mutagenicity and carcinogenicity was not strictly found among the compounds examined.

Biologic activities of poly (2-azaadenylic acid) and poly (2-azainosinic acid)

Poly (2-azaadenylic acid) [(aza2A)n] and poly(2-azainosinic acid [(aza2I)n], two newly synthesized analogues of (A)n and (I)n, in which CH-2 of the purine ring is replaced by a nitrogen atom, have been evaluated in various biological assay systems. (Aza2A) n formed a complex with (U)n and (br5U)n, and (aza2I)n formed a complex with (C)n and (br5C)n, but these complexes were markedly destabilized relative to the corresponding (A)n or (I)n complexes. The (aza2A)n-and (aza2I)n-derived complexes failed to stimulate the production of interferon in primary rabbit kidney cells and human diploid fibroblasts, under conditions (A)n. (U)n, (I)n. (C)n and (I)n. (br5C)n induced high amounts of interferon. both (aza2A)n and (aza2I)n exerted a marked inhibitory effect on the endogenous RNA directed DNA polymerase (reverse transcriptase) activity associated with murine leukemia virus. They caused a relatively mild inhibition of complement activity in an hemolytic assay system.