[Study on long-term morphological stability of three-dimensional-printed photosensitive resin dental models]

Objective: To study the long-term morphological stability of three-dimensional (3D) printed photosensitive resin dental models under natural light and dark conditions. Methods: Eighty sets of resin dental models were made by the desktop 3D printer from one digital standard model set, and randomly divided into two groups, namely natural light group (40 sets) and dark group (40 sets). All resin models were stored in sealed bags, with 4 model sets from each group randomly collected after 1, 3, 5, 7, 14, 21, 28, 40, 60, or 90 days of storage and 3D scanned using an optical model scanner. The root-mean-square error (RMSE) was calculated to represent the mean deviation of the difference between the digital standard model and the scanned resin model. Meanwhile, three linear indexes (the width between the canines, the width between the first molars, and the arch length) of the resin dental model were measured and compared with the corresponding values of the standard model. RMSE and the linear measurements between the digital standard model and the scanned resin models were compared between the natural light group and the dark group and among models from different time points. Results: Compared with the digital standard model, the RMSE values of 96.9% (155/160) resin dental models were less than 0.1 mm within 90-day storage. Also, at the same time point, there was no significant difference in the RMSE between the natural light group and the dark group (P>0.05). 75.0% (360/480) of the absolute values of the linear differences (differences in inter-canine width, intra-molar width, and arch length between the digital standard model and the scanned resin model) were within 0.2 mm, and about 0.1% (3/480) of the linear differences were greater than 0.5 mm, and all of the linear differences were within 0.6 mm. Conclusions: 3D-printed resin dental models can be stored stably under natural light and dark conditions for a long time.

[Clinical characteristics of 272 437 patients with different histopathological subtypes of primary esophageal malignant tumors]

Objective: To characterize the histopathological subtypes and their clinicopathological parameters of gender and onset age by common, rare and sparse primary esophageal malignant tumors (PEMT). Methods: A total of 272 437 patients with PEMT were enrolled in this study, and all of the patients were received radical surgery. The clinicopathological information of the patients was obtained from the database established by the State Key Laboratory of Esophageal Cancer Prevention & Treatment from September 1973 to December 2020, which included the clinical treatment, pathological diagnosis and follow-up information of esophagus and gastric cardia cancers. All patients were diagnosed and classified by the criteria of esophageal tumor histopathological diagnosis and classification (2019) of the World Health Organization (WHO). The esophageal tumors, which were not included in the WHO classification, were analyzed separately according to the postoperative pathological diagnosis. The χ² test was performed by the SPSS 25.0 software on count data, and the test standard α=0.05. Results: A total of 32 histopathological types were identified in the enrolled PEMT patients, of which 10 subtypes were not included in the WHO classification. According to the frequency, PEMT were divided into common (esophageal squamous cell carcinoma, ESCC, accounting for 97.1%), rare (esophageal adenocarcinoma, EAC, accounting for 2.3%) and sparse (mainly esophageal small cell carcinoma, malignant melanoma, etc., accounting for 0.6%). All the common, rare, and sparse types occurred predominantly in male patients, and the gender difference of rare type was most significant (EAC, male∶ female, 2.67∶1), followed with common type (ESCC, male∶ female, 1.78∶1) and sparse type (male∶ female, 1.71∶1). The common type (ESCC) mainly occurred in the middle thoracic segment (65.2%), while the rare type (EAC) mainly occurred in the lower thoracic segment (56.8%). Among the sparse type, malignant melanoma and malignant fibrous histiocytoma were both predominantly located in the lower thoracic segment (51.7%, 66.7%), and the others were mainly in the middle thoracic segment. Conclusion: ESCC is the most common type among the 32 histopathological types of PEMT, followed by EAC as the rare type, and esophageal small cell carcinoma and malignant melanoma as the major sparse type, and all of which are mainly occur in male patients. The common type of ESCC mainly occur in the middle thoracic segment, while the rare type of EAC mainly in the lower thoracic segment. The mainly sparse type of malignant melanoma and malignant fibrous histiocytoma predominately occur in the lower thoracic segment, and the remaining sparse types mainly occur in the middle thoracic segment.

The Opioid Crisis: Prevalence and Markets of Opioids

The US opioid crisis came in three waves - prescription opioids, heroin, and illicitly manufactured fentanyls - Centers for Disease Control and Prevention Centers for Disease Control and Prevention resulting in the deaths of nearly 500,000 people from 1996 to 2019. In 2009, drug overdose deaths exceeded those involving automobiles. Opioid overdose deaths contributed to the decrease in life expectancy for Americans from 78.8 to 78.5 during 2014 to 2017. The overprescribing of a schedule II prescription opioid was escalated by pharmaceutical companies promoting a growing belief that pain was an undertreated condition. In 2012, the number of opioid prescriptions peaked at 255 million and deaths exceeded 11,000 per year. The typical prescription opioid abuser was white, male, and 45-55 years of age. The hardest-hit states were in Appalachia and the Northeast. When an abuse-resistant formulation was introduced for OxyContin, the most prevalent prescription opioid, users turned to heroin. From the early 1980s, a new pizza delivery style of Mexican trafficking in black tar heroin infiltrated many of the same states hit hardest by prescription opioids. Heroin overdose deaths reached 14,495 in 2017. As heroin abuse increased in states supplied with black tar heroin, fentanyl-contaminated white powder heroin began to appear in the Northeast. Fentanyl was quickly followed by fentanyl analogs. While heroin deaths continued to escalate through 2017, they were soon overshadowed by fentanyl overdose deaths. Finally, prescription opioid and heroin overdose deaths started to decline in 2017, though fentanyl deaths continued to increase. In late 2019, it appeared that restrictions on transportation and travel due to the COVID-19 pandemic had resulted in decreased availability of illicit drugs, but by 2020 drug abuse had escalated in many countries. Globally, heroin was the primary opioid of abuse and only a few countries - including Canada, Germany, Austria, and Belgium - have experienced a significant increase in prescription opioids. However, illicitly manufactured fentanyls are a growing problem in North America, Europe, Australia, and Asia.

[Association between dietary vitamin A intake and gestational diabetes mellitus in the first trimester]

Objective: To investigate the relationship between dietary vitamin A intake and its sources in the first trimester and gestational diabetes mellitus (GDM). Methods: A prospective study was conducted to select women at 6-14 weeks of gestation in an obstetric clinic of a maternal and child health care medical institution in Chengdu in 2017. The types and quantities of food during the first trimester were collected by 3-day 24-hour dietary recalls. Dietary vitamin A intake was calculated based on the Chinese Food Composition Table (2018), and it was divided into animal and plant vitamin A intakes according to its food sources. An oral glucose tolerance test was performed at 24-28 weeks of gestation to diagnose GDM according to the Chinese guidelines for diagnosis and treatment of gestational diabetes mellitus (2014). According to the estimated average requirement (EAR) and recommended nutrient intake (RNI), dietary vitamin A intake was divided into low-level group (<EAR), medium-level group (EAR-RNI) and high-level group (>RNI). Animal and plant vitamin A intakes were divided into four groups (Q1-Q4) according to the quartile method, respectively. The association between dietary vitamin A intake, its different sources of vitamin A intake and GDM in the first trimester was analyzed by log-binomial regression models. Results: A total of 1 298 valid samples were finally included. The average dietary vitamin A intake, animal and plant vitamin A intakes in the first trimester were 341.1 (227.8-501.0) μgRAE/d, 139.3 (69.6-195.3) μgRAE/d and 184.2 (99.4-301.1) μgRAE/d, respectively. After adjusting for confounding factors, log-binomial regression analysis showed that the risk of GDM in high-level group of dietary vitamin A intake was lower than that in low-level group [RR (95%CI):0.53 (0.36-0.80)]. Pregnant women in the highest quartile of animal vitamin A intake had a lower risk of GDM than those in the lowest quartile [RR (95%CI):0.66 (0.47-0.95)]. No relationship between plant vitamin A intake and GDM was found. Conclusion: Dietary vitamin A intake in the first trimester is associated with the occurrence of GDM, and higher intake than RNI may reduce the risk of GDM. Higher vitamin A intake from animal-derived food is associated with decreased risk of GDM.

A Systematic Thermal Analysis for Accurately Predicting the Extrusion Printability of Alginate-Gelatin-Based Hydrogel Bioinks

Three-dimensional (3D) bioprinting has significant potential for addressing the global problem of organ shortages. Extrusion printing is a versatile 3D bioprinting technique, but its low accuracy currently limits the solution. This lack of precision is attributed largely to the complex thermal and dynamic properties of bioinks and makes it difficult to provide accurate estimations of the printed results. It is necessary to understand the relationship between printing temperature and materials’ printability to address this issue. This paper proposes a quantitative thermal model incorporating a system’s printing temperatures (syringe, ambient, and bioink) to facilitate accurate estimations of the printing outcomes. A physical model was established to reveal the relationship between temperature, pressure, and velocity in guiding the printing of sodium alginate–gelatin composite hydrogel (a popular bioink) to optimize its extrusion-based printability. The model considered the phenomenon of bioink die swells after extrusion. A series of extrusion experiments confirmed that the proposed model offers enhanced printing outcome estimations compared with conventional models. Two types of nozzles (32- and 23-gauge) were used to print several sets of lines with a linewidth step of 50 mm by regulating the extrudate’s temperature, pressure, and velocity separately. The study confirmed the potential for establishing a reasonable, accurate open-loop linewidth control based on the proposed optimization method to expand the application of extrusion-based bioprinting further.

[Association between dietary glycemic load during first trimester and the risk of gestational diabetes mellitus: a prospective study]

Objective: To explore the effects of dietary glycemic load (GL) during first trimester on the risk of gestational diabetes mellitus (GDM). Methods: A prospective study was conducted among healthy women with singleton pregnancy at 8-14 weeks of gestation in a maternity out-patient clinic of maternal-and-child health care institution in Chengdu, Sichuan province. Information on dietary intake during the first trimester was collected through a 3-day 24-hour dietary recall. Glycemic index (GI) values were obtained from China Food Composition Tables (Standard Edition) and International Tables of Glycemic Index and Glycemic Load Values (2008). Dietary GL and GLs of staple foods were calculated based on GI values and the amount of carbohydrate consumed per day. Diagnostic criteria of GDM was followed the Guidelines for Diagnosis and Treatment of Pregnancy Diabetes in China (2014), and used on participants who underwent an oral glucose tolerant test during 24-28 weeks of gestation. Log-binomial regression models were used to explore the associations between both quartiles of dietary GL, GLs of staple foods and the risks of GDM,respectively. Results: The medians of dietary GL and GL of staple foods were 145.70 (113.23-180.85) and 121.05 (89.08-155.70), respectively. The median GL of both rice and tubers were 73.14 (43.89-107.50) and 3.43 (0.00-9.84), respectively. After adjusting for the age at pregnancy, pre-pregnancy body mass index and other confounding factors, results of log-binomial regressions analysis showed that when compared with the lowest quartile of dietary GL group, the third and highest quartiles of dietary GL groups increased the risk of GDM (RR=1.47, 95%CI: 1.20-1.80; RR=1.31, 95%CI: 1.04-1.64), respectively. Compared with the lowest quartile of GL of staple foods, the third and highest quartiles of GL of staple foods groups also increased the risk of GDM (RR=1.28, 95%CI: 1.04-1.58; RR=1.27, 95%CI: 1.02-1.60), respectively. The third and highest quartiles of GL of rice groups increased the risk of GDM (RR=1.30, 95%CI: 1.06-1.59; RR=1.28, 95%CI: 1.03-1.59), respectively, than the lowest quartile of GL of rice group. When compared with the lowest quartile of GL of tubers group, the highest quartile of GL of tubers group increased the risk of GDM (RR=1.30, 95%CI: 1.09-1.54). However, we did not notice the effects of wheat GL and coarse grain GL on the risk of GDM. Conclusions: A positive association was found between dietary glycemic load and the risk of GDM. Higher dietary glycemic load, especially in rice and tubers during first trimester, seemed to have increased the risk of GDM.

Association of Dysplastic Coronoid Process with Long-Face Morphology

Vertical malocclusion is a developmental condition, resulting from complex interactions among multiple etiological factors during the growth period. As a tricky dentofacial deformity clinically, long-face (LF) morphology is characterized by excessive vertical facial growth with severe disarrangement of jaws and teeth. Since the improvement of LF patients on facial profile and occlusion is often difficult and lacks long-term stability, it becomes important to unravel the etiology of LF pattern formation for early prevention and treatment. In the current studies, we identified a transgenic mouse model that exhibited a dysplastic coronoid process and LF morphology. Although the mutant mice exhibited jaw structures and occlusion comparable to controls at birth, they all acquired typical LF morphology with anterior open bite during postnatal growth, resembling clinical features of the selected skeletal class III patients. Since the coronoid process provides an insertion site for the temporalis attachment, we examined the initial development and differentiation of the temporalis and found identical results in both control and mutant mice before E17.5 when the temporal muscle makes attachment to the coronoid process. However, thereafter, we observed altered orientation and reduced size of the cross-sectional area of the temporalis in mutant mice, which persisted to the weaning stage. Biomechanical analysis and simulation modeling further support the idea that altered morphology of the coronoid process may impair the efficiency of the vertical temporalis contraction and appears to correlate with LF formation. Consistently, we present evidence that a dysplastic mandibular coronoid process was also seen in some human patients with skeletal III LF morphology. Taken together, the results presented in this study establish an association of the craniofacial bony structures with vertical patterning, which will have implications in earlier prediction for clinical precaution and intervention.

Smad7 Regulates Dental Epithelial Proliferation during Tooth Development

Tooth morphogenesis involves dynamic changes in shape and size as it proceeds through the bud, cap, and bell stages. This process requires exact regulation of cell proliferation and differentiation. Smad7, a general antagonist against transforming growth factor-β (TGF-β) signaling, is necessary for maintaining homeostasis and proper functionality in many organs. While TGF-β signaling is widely involved in tooth morphogenesis, the precise role of Smad7 in tooth development remains unknown. In this study, we showed that Smad7 is expressed in the developing mouse molars with a high level in the dental epithelium but a moderate to weak level in the dental mesenchyme. Smad7 deficiency led to a profound decrease in tooth size primarily due to a severely compromised cell proliferation capability in the dental epithelium. Consistent with the tooth shrinkage phenotype, RNA sequencing (RNA-seq) analysis revealed that Smad7 ablation downregulated genes referred to epithelial cell proliferation and cell cycle G1/S phase transition, whereas the upregulated genes were involved in responding to TGF-β signaling and cell cycle arrest. Among these genes, the expression of Cdkn1a (encoding p21), a negative cell proliferation regulator, was remarkably elevated in parallel with the diminution of Ccnd1 encoding the crucial cell cycle regulator cyclin D1 in the dental epithelium. Meanwhile, the expression level of p-Smad2/3 was ectopically elevated in the developing tooth germ of Smad7 null mice, indicating the hyperactivation of the canonical TGF-β signaling. These effects were reversed by addition of TGF-β signaling inhibitor in cell cultures of Smad7^-/- molar tooth germs, with rescued expression of cyclin D1 and cell proliferation rate. In sum, our studies demonstrate that Smad7 functions primarily as a positive regulator of cell proliferation via inhibition of the canonical TGF-β signaling during dental epithelium development and highlight a crucial role for Smad7 in regulating tooth size.

A note on cloning and analysis of the osteopontin gene with egg quality traits in two Chinese domestic ducks

1. Osteopontin (OPN) is a highly phosphorylated acidic glycoprotein that plays a crucial role in eggshell formation. In this study, an 893-bp cDNA sequence of the OPN gene, which encodes 180 amino acids, was obtained. 2. Polymorphisms of the OPN gene were analysed with DNA sequencing and polymerase chain reaction-single-strand conformation polymorphism methods in two Chinese domestic laying ducks (Jingding n = 100, Youxian n = 478, respectively). 3. One polymorphism was identified in exon 7 (NM_ 004676534.1:c.267T>C) of the OPN gene, with three genotypes: TT (both T allels weren't mutated (wild type)), TC (one T allel was mutated to C (heterozygote genotype)) and CC. (both T allels were mutated to C (homozygote 20 genotype)) Association analysis with egg quality traits in the two Chinese domestic laying ducks showed that the ducks with the CC genotype had significantly greater eggshell strength and eggshell thickness (p < 0.05). Hence, the exon 7 267T>C polymorphism of the OPN gene is a potentially valuable genetic marker for laying duck breeding programmes.

Short-course Regimen for Subsequent Treatment of Pulmonary Tuberculosis: A Prospective, Randomized, Controlled Multicenter Clinical Trial in China

PURPOSE

We designed a prospective, multicenter, randomized, controlled study to assess a 5-month regimen compared with the standard regimen on previously treated patients with pulmonary tuberculosis (TB).

METHODS

We enrolled 917 sputum smear-positive patients undergoing additional treatment in 27 major tuberculosis hospitals in China. Patients were randomly assigned to a test group (n = 626)treated with a 5-month regimen of moxifloxacin, pasiniazid, rifabutin, ethambutol, and pyrazinamide or a reference group (n = 291) treated with an 8-month regimen of isoniazid, rifampicin, and streptomycin. All patients with a favorable response were followed up for 5 years after the end of treatment.

FINDINGS

Of the study patients, 61 in the test group and 19 in the reference group had multidrug-resistant (MDR) TB. The treatment success rate in the study group was 74.12%, which was significantly higher than the 67.70% in the reference group (P = 0.04), whereas the treatment success rate of patients with MDR-TB was not significantly different between the test and reference groups (70.5% vs 63.1%, P =0.79). The adverse effects rates in the test and reference groups were 7.4% and 3.1%, respectively (P = .01). The difference in the TB recurrence rates between the group arm (9.6%) and the reference group (21.8%) was statistically significant (P < 0.001).

IMPLICATIONS

The moxifloxacin, pasiniazid, rifabutin, ethambutol, and pyrazinamide test regimen yielded higher success and lower recurrence rates than the currently recommended isoniazid, rifampicin, and streptomycin regimen, but the rate of adverse effects was higher. ClinicalTrials.gov identifier: NCT02331823.

Pharmacokinetics of orbifloxacin in crucian carp (Carassius auratus) after intravenous and intramuscular administration

The pharmacokinetics of orbifloxacin was studied after a single dose (7.5 mg/kg) of intravenous or intramuscular administration to crucian carp (Carassius auratus) reared in freshwater at 25°C. Plasma samples were collected from six fish per sampling point. Orbifloxacin concentrations were determined by high-performance liquid chromatography with a 0.02 μg/ml limit of detection, then were subjected to noncompartmental analysis. After intravenous injection, initial concentration of 5.83 μg/ml, apparent elimination rate constant (λ_z ) of 0.039 hr^-1 , apparent elimination half-life (T_1/2λz ) of 17.90 hr, systemic total body clearance (Cl) of 75.47 ml hr^-1  kg^-1 , volume of distribution (Vz) of 1,948.76 ml/kg, and volume of distribution at steady-state (Vss) of 1,863.97 ml/kg were determined, respectively. While after intramuscular administration, the λ_z , T_1/2λz , mean absorption time (MAT), absorption half-life (T_1/2ka ), and bioavailability were determined as 0.027 hr^-1 , 25.69, 10.26, 7.11 hr, and 96.46%, respectively, while the peak concentration was observed as 3.11 ± 0.06 μg/ml at 2.0 hr. It was shown that orbifloxacin was completely but relatively slowly absorbed, extensively distributed, and slowly eliminated in crucian carp, and an orbifloxacin dosage of 10 mg/kg administered intravenously or intramuscularly would be expected to successfully treat crucian carp infected by strains with MIC values ≤0.5 μg/ml.

Attenuation of Focal Adhesion Kinase Reduces Lipopolysaccharide-Induced Inflammation Injury through Inactivation of the Wnt and NF-κB Pathways in A549 Cells

Overall analysis and understanding of mechanisms are of great importance for treatment of infantile pneumonia due to its high morbidity and mortality worldwide. In this study, we preliminarily explored the function and mechanism of focal adhesion kinase (FAK) in regulation of inflammatory response induced by lipopolysaccharides in A549 cells. Flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, quantitative reverse transcription polymerase chain reaction, and Western blot analysis were used to explore the correlation of FAK expression with cell apoptosis, viability, and the inflammatory cytokine activity in A549 cells. The results showed that knockdown of FAK enhanced cell viability, suppressed apoptosis, and decreased inflammatory cytokine activity. In addition, downregulation of FAK could activate the Wnt and nuclear factor κB signaling pathways. These findings suggest that FAK might be involved in progression of infantile pneumonia and could be a new therapeutic target for this disease.

[Electrothermal acupuncture in the prevention and treatment of chemotherapy-induced nausea and vomiting:a randomized controlled trial]

OBJECTIVE

To observe the effectiveness and safety of electrothermal acupuncture in the prevention and treatment of chemotherapy-induced nausea and vomiting (CINV) in the cancerous patients of phlegm-stasis interaction in cisplatin-containing chemotherapy.

METHODS

Sixty cases of phlegm-stasis interaction in cisplatin-containing chemotherapy were randomized into a trial group and a control group, 30 cases in each one. In the control group, the intravenous drip of granisetron hydrochloride injection was adopted, 3 mg before and after cisplatin-containing chemotherapy 30 min, continuously for 3 days. 43 to 45℃ electrothermal acupuncture at zusanli(ST 36) for 30 min was used on the basis of the treatment as the control group in the trial group,once a day for 3 days. CINV, anti-nausea effects, Karnofsky score, the syndrome score of phlegm-stasis interaction, and relevant indices of safety were observed on the 1st and 7th days of cisplatin-containing chemotherapy separately.

RESULTS

1.Regarding CINV and anti-nausea effect, CINV did not occur before chemotherapy in the patients of the two groups. On the 1st and 7th days of chemotherapy, CINV in the trial group were milder than those in the control group (both P<0.05).The anti-nausea effects in the trail group were better than those of the control group.2.Regarding Karnofsky score and the syndrome score of phlegm-stasis interaction, the improvements on the 7th days of chemotherapy in the trial group were better than those in the control group, indicating the significant differences (both P<0.05). 3.Regarding the safety indies, there was no adverse reaction during the treatment in the two groups.

CONCLUSIONS

The electrothermal acupuncture effectively relieves CINV, and improves self-care dbility and the symptoms of phlegm-stasis interaction.

Confocal imaging of mouse mandibular condyle cartilage

Mice are commonly used to study the temporomandibular joint (TMJ) and to model human TMJ disease. However, evaluating TMJ pathology in mice using standard histologic methods is time consuming, labor intensive, and dependent upon investigators’ expertise at consistently orienting and sectioning across tiny specimens. We describe a method that uses confocal microscopy to rapidly and reliably assess indicators of mandibular condyle cartilage pathology in mice. We demonstrate the utility of this method for detecting abnormalities in chondrocyte distribution in mice lacking lubricin (Prg4), the major boundary lubricant of articular cartilage. We further show that the method can provide information about recombination sites and efficiency in mandibular cartilage for Cre-driver strains. Because specimen preparation and data acquisition with confocal microscopy are simple and fast, the method can serve as a primary screening tool for TMJ pathology, before proceeding to complicated, time consuming, secondary analyses.

Emtonjeni-A Structural Intervention to Integrate Sexual and Reproductive Health into Public Sector HIV Care in Cape Town, South Africa: Results of a Phase II Study

Integration of sexual and reproductive health within HIV care services is a promising strategy for increasing access to family planning and STI services and reducing unwanted pregnancies, perinatal HIV transmission and maternal and infant mortality among people living with HIV and their partners. We conducted a Phase II randomized futility trial of a multi-level intervention to increase adherence to safer sex guidelines among those wishing to avoid pregnancy and adherence to safer conception guidelines among those seeking conception in newly-diagnosed HIV-positive persons in four public-sector HIV clinics in Cape Town. Clinics were pair-matched and the two clinics within each pair were randomized to either a three-session provider-delivered enhanced intervention (EI) (onsite contraceptive services and brief milieu intervention for staff) or standard-of-care (SOC) provider-delivered intervention. The futility analysis showed that we cannot rule out the possibility that the EI intervention has a 10 % point or greater success rate in improving adherence to safer sex/safer conception guidelines than does SOC (p = 0.573), indicating that the intervention holds merit, and a larger-scale confirmatory study showing whether the EI is superior to SOC has merit.

Dental, skeletal asymmetries and functional characteristics in Class II subdivision malocclusions

Treatment outcomes of Angle Class II subdivision malocclusions may be compromised because of the uncertainty of the aetiology. Previous studies have reported controversial ideas about the origins, but the existence of a primary contributor still remains unknown. Functional factors have been mentioned as a probable cause, but until now, there have been no supporting data. This study was a cross-sectional investigation of the characteristics of Angle Class II subdivision malocclusion, including dental, skeletal and functional factors, by comparison of the subdivision group and the normal occlusion group. The evaluations of dental and skeletal asymmetries of both groups were carried out by cone-beam computed tomography (CBCT) and analysis of dental casts. The functional deviations were evaluated by cast mounting and measuring. In the subdivision group, the asymmetric position of the glenoid fossa was found to be the most significant skeletal asymmetry. No dentoalveolar asymmetry was found in this group. The most important finding was that, in subdivision malocclusions, functional deviation resulting in pseudoasymmetry occurred in 32.86% of the study participants. This deviation is probably related to the disharmonious arch width between maxillary and mandibular dental arches in the premolar section. The origin of Angle Class II subdivision malocclusion is multifactorial, with dental, skeletal and functional factors included. Functional deviation occurs, probably due to dental arch width disharmony. Asymmetric position of the glenoid fossa may account for most of the skeletal asymmetry.

[The effect of renal replacement therapy on the plasma concentration of antituberculosis drugs]

OBJECTIVE

To explore the effect of renal replacement therapy (RRT) on the plasma drug concentration of first-line antituberculosis drugs.

METHODS

Thirty patients treated with continuous RRT and who were complicated with pulmonary tuberculosis from 2009 September to 2013 September were enrolled in the study. There were 19 males and 11 females, aged 18-75 years. They received RRT 3 times a week, 4 h each. The patients took isoniazid 300 mg and rifampin 450 mg one time every day, and pyrazinamide 40 mg · kg(-1) · d (-1) one time 24 h before RRT, 3 times every week. The plasma concentration of the drugs were monitored before and after each RRT for 4 weeks.

RESULTS

Taken before RRT, the plasma concentration of isoniazid before RRP was (1.62 ± 0.44), (1.67 ± 0.38), (1.63 ± 0.41), (1.48 ± 0.38) mg/L respectively for 1-4 weeks; while that after RRT was (0.57 ± 0.22), (0.60 ± 0.24), (0.56 ± 0.20), (0.56 ± 0.15) mg/L (all P < 0.05). Taken before RRT, the plasma concentration of pyrazinamide before RRT was (16.08 ± 4.95), (16.32 ± 5.73), (14.89 ± 4.53), (13.81 ± 5.83) mg/L respectively for 1-4 weeks, while that after RRT was (3.73 ± 1.57), (3.57 ± 1.53), (3.22 ± 1.00), (2.81 ± 1.34) mg/L (all P < 0.05). Taken after RRT at once, the plasma concentration of pyrazinamide before RRT was (15.57 ± 3.47), (14.10 ± 2.27), (14.73 ± 2.36), (15.9 ± 3.02) mg/L respectively for 1-4 weeks, while that after RRT was (2.45 ± 1.14), (2.19 ± 1.07), (1.87 ± 1.52), (2.33 ± 1.30)mg/L. Taken before RRT, the plasma concentration of rifampin was (3.44 ± 1.17), (3.72 ± 1.24), (3.68 ± 1.16), (3.44 ± 1.22) mg/L respectively for 1-4 weeks (all P < 0.05), while that after RRT was (2.96 ± 1.10), (3.28 ± 1.04), (3.17 ± 1.02), (2.96 ± 1.05) mg/L (all P > 0.05).

CONCLUSIONS

Continuous RRT has different effects on the plasma drug concentration of isoniazid and pyrazinamide. It almost has no effect on rifampin. To achieve the best plasma concentration and better anti-tuberculosis results, isoniazid and pyrazinamide should be taken after RRT, but rifampin before RRT.

Genetic diversity in North American ginseng (Panax quinquefolius L.) grown in Ontario detected by RAPD analysis

Genetic diversity within North American ginseng (Panax quinquefolius L.) grown in Ontario was investigated at the DNA level using the randomly amplified polymorphic DNA (RAPD) method via the polymerase chain reaction (PCR). A total of 420 random decamers were initially screened against DNA from four ginseng plants and 78.8% of them generated RAPD fragments. Thirty-six of the decamers that generated highly repeatable polymorphic RAPD markers were selected for further RAPD analysis of the ginseng population. With these primers, 352 discernible DNA fragments were produced from DNA of 48 ginseng plants, corresponding to an average of 9.8 fragments per primer, of which over 45% were polymorphic. The similarity coefficients among the DNA of ginseng plants analyzed were low, ranging from 0.149 to 0.605 with a mean of 0.412, indicating that a high degree of genetic diversity exists in the ginseng population. Lower levels of genetic diversity were detected among 3-year-old ginseng plants selected on the basis of greater plant height than among the plants randomly selected from the same subpopulation or over the whole population, suggesting that genetic factors at least partly contribute to morphological variation within the ginseng population and that visual selection can be effective in identifying the genetic differences. The significance of a high degree of genetic variation in the ginseng population on its potential for improvement by breeding is also discussed.

Novel mutations in Myoclonin1/EFHC1 in sporadic and familial juvenile myoclonic epilepsy

BACKGROUND

Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, the GENESS Consortium demonstrated four missense mutations in Myoclonin1/EFHC1 of chromosome 6p12.1 segregating in 20% of Hispanic families with JME.

OBJECTIVE

To examine what percentage of consecutive JME clinic cases have mutations in Myoclonin1/EFHC1.

METHODS

We screened 44 consecutive patients from Mexico and Honduras and 67 patients from Japan using heteroduplex analysis and direct sequencing.

RESULTS

We found five novel mutations in transcripts A and B of Myoclonin1/EFHC1. Two novel heterozygous missense mutations (c.755C>A and c.1523C>G) in transcript A occurred in both a singleton from Mexico and another singleton from Japan. A deletion/frameshift (C.789del.AV264fsx280) in transcript B was present in a mother and daughter from Mexico. A nonsense mutation (c.829C>T) in transcript B segregated in four clinically and seven epileptiform-EEG affected members of a large Honduran family. The same nonsense mutation (c.829C>T) occurred as a de novo mutation in a sporadic case. Finally, we found a three-base deletion (-364--362del.GAT) in the promoter region in a family from Japan.

CONCLUSION

Nine percent of consecutive juvenile myoclonic epilepsy cases from Mexico and Honduras clinics and 3% of clinic patients from Japan carry mutations in Myoclonin1/EFCH1. These results represent the highest number and percentage of mutations found for a juvenile myoclonic epilepsy causing gene of any population group.

Purification and characterization of a lipopeptide produced by Bacillus thuringiensis CMB26

AIMS

To isolate an antagonist for use in the biological control of phytopathogenic fungi including Colletotrichum gloeosporioides, then to purify and characterize the biocontrol agent produced by the antagonist.

METHODS AND RESULTS

Bacteria that exhibited antifungal activity against the causative agent pepper anthracnose were isolated from soil, with Bacillus thuringiensis CMB26 showing the strongest activity. A lipopeptide produced by B. thuringiensis CMB26 was precipitated by adjusting the pH 2 with 3 n HCl and extracted using chloroform/methanol (2:1, v/v) and reversed-phase HPLC. The molecular weight was estimated as 1447 Da by MALDI-TOF mass spectrometry. Scanning electron and optical microscopies showed that the lipopeptide has activity against Escherichia coli O157:ac88, larvae of the cabbage white butterfly (Pieris rapae crucivora) and phytopathogenic fungi. The lipopeptide had cyclic structure and the amino acid composition was L-Glu, D-Orn, L-Tyr, D-allo-Thr, D-Ala, D-Val, L-Pro, and L-Ile in a molar ratio of 3:1:2:1:1:2:1:1. The purified lipopeptide showed the same amino acid composition as fengycin, but differed slightly in fatty acid composition, in which the double bond was at carbons 13-14 (m/z 303, 316) and there was no methyl group.

CONCLUSION

A lipopeptide was purified and characterized from B. thuringiensis CMB26 and found to be similar to the lipopeptide fengycin. This lipopeptide can function as a biocontrol agent, and exhibits fungicidal, bactericidal, and insecticidal activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

Compared with surfactin and iturin, the lipopeptide from B. thuringiensis CMB26 showed stronger antifungal activity against phytopathogenic fungi. This lipopeptide is a candidate for the biocontrol of pathogens in agriculture.

[Juvenile myoclonic epilepsy in chromosome 6p12: clinical and genetic advances]

Amongst idiopathic generalized epilepsies, juvenile myoclonic epilepsy (JME) is the most common, accounting for 12% to 30% of all epilepsies in the Western world. Classic JME consists of awakening myoclonias, grand mal convulsions and EEG 4 to 6 Hz polyspike waves that appear in adolescence. Probands and affected family members do not have pyknoleptic 3Hz spike and wave absences. However, in 10 to 30% of patients, rare or spanioleptic polyspike wave absences appear. In 1988,1995,1996,we mapped classic JME to a 7 cM locus in chromosome 6p12 11, called EJM1, using families from Los Angeles and Belize. In 2001,we studied one large family from Belize and 21 new families from Los Angeles and Mexico Cities, aided by a BAC/PAC based physical map and 6 new dinucleotide repeats, to narrow EJM1 to an interval between D6S272 and D6S1573. In 2002, we found myoclonin, the putative gene for typical JME in 6p12. At the congress, we will reveal the identity of the myoclonin gene, its putative function and discuss the significance of this discovery in the JME population at large.

A novel cloud-point extraction process for preconcentrating selected polycyclic aromatic hydrocarbons in aqueous solution

A novel but simple cloud-point extraction (CPE) process is developed to preconcentrate the trace of selected polycyclic aromatic hydrocarbons (PAHs) with the use of the readily biodegradable nonionic surfactant Tergitol 15-S-7 as extractant. The concentrations of PAHs, mixtures of naphthalene and phenanthrene as well as pyrene, in the spiked samples were determined with the new CPE process at ambient temperature (23 degrees C) followed by high performance liquid chromatography(HPLC) with fluorescence detection. More than 80% of phenanthrene and pyrene, respectively, and 96% of naphthalene initially present in the aqueous solutions with concentrations near or below their aqueous solubilities were recovered using this new CPE process. Importantly Tergitol 15-S-7 does not give any fluorometric signal to interfere with fluorescence detection of PAHs in the UV range. No special washing step is, thus, required to remove surfactant before HPLC analyses. Different experimental conditions were studied. The optimum conditions for the preconcentration and determination of these selected PAHs at ambient temperature have been established as the following: (1) 3 wt% surfactant; (2) addition of 0.5 M Na2SO4; (3) 10 min for equilibration time; and (4) 3000 rpm for centrifugal speed with duration of 10 min.

[Inhibitive effects of lip repair on maxillary growth in patients with complete unilateral cleft lip and palate]

OBJECTIVE

The aim of this study was to assess the isolated effects of lip repair on inhibition of maxillary growth in patients with complete unilateral cleft lip and palate.

METHODS

The lateral cephalometric analysis were applied to 20 patients with unilateral cleft lip and palate who only had lip repaired in childhood, 32 patients with unilateral cleft lip and palate who had both lip and palate repaired in childhood, as well as 37 normal Chinese of the same age as controls.

RESULTS

Both complete unilateral cleft lip and palate groups had almost the same significant degree of maxillary retrusion compared with the normal control group.

CONCLUSION

Lip repair is one of important factors that could inhibit maxillary growth in patients with complete unilateral cleft lip and palate.

Modulation of AMPA receptors by a novel organic nitrate

Positive modulators of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) channels reduce desensitization and alter their gating kinetics. We have discovered a novel compound nitric oxide-mimetic that similarly modulates the AMPA receptor by reducing desensitization. This, designated GT-005, belongs to the organic nitrate family that includes the nitrovasodilator nitroglycerine. In acutely isolated hippocampal neurons, GT-005 enhanced kainate (100 microM)-evoked currents with an EC50 of 1.7+/-0.2 mM and a 176+/-10% maximal increase in the steady-state current response. Similar results were found in cultured hippocampal neurons (EC50 of 1.3+/-0.2 mM and a maximal 83+/-14% increase in the steady-state current response). GT-005 reduced the desensitization of glutamate-evoked currents and slowed the onset of desensitization. This compound also increased the rate of recovery from the desensitized state. With respect to alteration of the excitatory synaptic transmission, GT-005 delayed the decay and increased the frequency of spontaneous miniature excitatory postsynaptic currents (mepsc) recorded in cultured hippocampal neurons.

Distinct functional and pharmacological properties of tonic and quantal inhibitory postsynaptic currents mediated by gamma-aminobutyric acid(A) receptors in hippocampal neurons

gamma-Aminobutyric acid (GABA), the principal inhibitory neurotransmitter, activates a persistent low amplitude tonic current in several brain regions in addition to conventional synaptic currents. Here we demonstrate that GABA(A) receptors mediating the tonic current in hippocampal neurons exhibit functional and pharmacological properties different from those of quantal synaptic currents. Patch-clamp techniques were used to characterize miniature inhibitory postsynaptic currents (mIPSCs) and the tonic GABAergic current recorded in CA1 pyramidal neurons in rat hippocampal slices and in dissociated neurons grown in culture. The competitive GABA(A) receptor antagonists, bicuculline and picrotoxin, blocked both the mIPSCs and the tonic current. In contrast, mIPSCs but not the tonic current were inhibited by gabazine (SR-95531). Coapplication experiments and computer simulations revealed that gabazine bound to the receptors responsible for the tonic current but did not prevent channel activation. However, gabazine competitively inhibited bicuculline blockade. The unitary conductance of the GABA(A) receptors underlying the tonic current (approximately 6 pS) was less than the main conductance of channels activated during quantal synaptic transmission (approximately 15--30 pS). Furthermore, compounds that potentiate GABA(A) receptor function including the benzodiazepine, midazolam, and anesthetic, propofol, prolonged the duration of mIPSCs and increased tonic current amplitude in cultured neurons to different extents. Clinically-relevant concentrations of midazolam and propofol caused a greater increase in tonic current compared with mIPSCs, as measured by total charge transfer. In summary, the receptors underlying the tonic current are functionally and pharmacologically distinct from quantally activated synaptic receptors and these receptors represent a novel target for neurodepressive drugs.

Regulation of T cell activation, anxiety, and male aggression by RGS2

Regulators of G protein signaling (RGS) proteins accelerate the GTPase activity of Galpha protein subunits in vitro, negatively regulating G protein-coupled receptor signaling. The physiological role of mammalian RGS proteins is largely unknown. The RGS family member rgs2 was cloned as an immediate early response gene up-regulated in T lymphocytes after activation. To investigate the role of RGS2 in vivo, we generated rgs2-deficient mice. We show that targeted mutation of rgs2 in mice leads to reduced T cell proliferation and IL-2 production, which translates in an impaired antiviral immunity in vivo. Interestingly, rgs2(-/-) mice also display increased anxiety responses and decreased male aggression in the absence of cognitive or motor deficits. RGS2 also controls synaptic development and basal electrical activity in hippocampal CA1 neurons. Thus, RGS2 plays an important role in T cell activation, synapse development in the hippocampus, and emotive behaviors.

Stilbene glycoside sulfates from Polygonum cuspidatum

Ten naturally occurring stilbene glycoside sulfates (1-10) were isolated from an aqueous extract of the root of Polygonum cuspidatum. Their structures were established based on chemical evidence and spectroscopic techniques, including 2D NMR methods.

Immunocytochemical localization of putative gamma-aminobutyric acid receptor subunits in the head ganglia of Periplaneta americana using an anti-RDL C-terminal antibody

A polyclonal antibody raised against a 17 amino acid polypeptide (the predicted C-terminal sequence of the cloned Drosophila melanogaster gamma-aminobutyric acid (GABA) receptor subunit, RDL) was used to investigate the distribution of GABA receptor subunit(s) of this type in the nervous system of the cockroach Periplaneta americana. Intense staining was detected in the calyces of the mushroom bodies, glomeruli of the antennal lobes, lower central body, the corpora cardiaca and several cell layers of the medulla and the lobula regions of the optic lobe. The most intense immunocytochemical staining was in the suboesophageal ganglion. Control sections pre-incubated with the primary antibody and conjugated peptide were not stained. Thus, it appears that a GABA receptor subunit of the RDL type is located in cockroach brain regions involved in the processing of visual, olfactory and mechanosensory inputs to the nervous system. Since the corpora cardiaca reacted to this antiserum, this type of GABA receptor may also be involved in the regulation of neurosecretory activity.

[A study on the intrinsic compensative mechanism of craniofacial soft and hard tissue structures of Uygur adults with normal occlusion]

OBJECTIVE

To study the intrinsic compensative mechanism of craniofacial soft and hard tissue structures of Uygur adults with normal occlusion and establish standard cephalometric values to evaluate craniofacial soft and hard tissue structures of normal Uygur adults.

METHODS

Lateral cephalometric radiographs of 93 Uygur adults with normal occlusion (43 men and 50 women) were evaluated with the same standard. Their age ranged from 18 to 25 years old, and they had normal and well-balanced faces without receiving any orthodontic treatment. Based on the study of craniofacial soft and hard tissue structures with normal occlusion, the horizontal tendency, the vertical tendency pattern and the medial pattern of craniofacial soft and hard tissue structures were compared, and the intrinsic compensative mechanism in the inner structures of the horizontal and the vertical tendency patterns was investigated. Finally 21 indexes were analysed by mean squar deviation and Newman-Keuls test.

RESULTS

The obvious compensative changes in the horizontal and vertical tendency patterns were found in teeth, skeleton and soft-tissues. 1. When the horizontal tendency was compared with the medial pattern, the value of ODI and angles of FH-NA and FH-NB increased (P < 0.01), while the angle of SN-PP decreased (P < 0.01). It showed that the anterior maxilla rotated in the counter-clockwise direction, and the anterior mandible rotated in the clockwise direction. The angle of U1-L1 increased (P < 0.01), which meant that the inclination of anterior teeth decreased. 2. When the vertical tendency was compared with the medial pattern, the value of ODI decreased (P < 0.01), while the height of ANS-Me, U1-PP, L1-MP, and the thickness of LL-SnPg increased (P < 0.01); The angle of L1-MP decreased (P < 0.05), while the length of Sn-Stms increased (P < 0.05). These results showed that there was an obvious positive relationship between hard and soft tissues. The soft tissue thickness could compensate the changes of hard tissues to keep the facial patterns harmony.

CONCLUSION

Normal occlusion depends on the homeostasis of teeth, skeleton and soft tissues, but doesn't only depend on the normal craniofacial soft and hard tissue structures respectively. The intrinsic compensative mechanism plays an important role in forming normal occlusion, therefore, doctors should choose the best treatment to obtain optimal individual intrinsic compensative mechanism and achieve an optimal balance between the craniofacial structures and the occlusion.

In CA1 pyramidal neurons of the hippocampus protein kinase C regulates calcium-dependent inactivation of NMDA receptors

The NMDA subtype of the glutamate-gated channel exhibits a high permeability to Ca(2+). The influx of Ca(2+) through NMDA channels is limited by a rapid and Ca(2+)/calmodulin (CaM)-dependent inactivation that results from a competitive displacement of cytoskeleton-binding proteins from the NR1 subunit of the receptor by Ca(2+)/CaM (Zhang et al., 1998; Krupp et al., 1999). The C terminal of this subunit can be phosphorylated by protein kinase C (PKC) (Tingley et al., 1993). The present study sought to investigate whether PKC regulates Ca(2+)-dependent inactivation of the NMDA channel in hippocampal neurons. Activation of endogenous PKC by 4beta-phorbol 12-myristate 13-acetate enhanced peak (I(p)) and depressed steady-state (I(ss)) NMDA-evoked currents, resulting in a reduction in the ratio of these currents (I(ss)/I(p)). We demonstrated previously that PKC activity enhances I(P) via a sequential activation of the focal adhesion kinase cell adhesion kinase beta/proline-rich tyrosine kinase 2 (CAKbeta/Pyk2) and the nonreceptor tyrosine kinase Src (Huang et al., 1999; Lu et al., 1999). Here, we report that the PKC-induced depression of I(ss) is unrelated to the PKC/CAKbeta/Src-signaling pathway but depends on the concentration of extracellular Ca(2+). Intracellular applications of CaM reduced I(ss)/I(p) and occluded the Ca(2+)-dependent effect of phorbol esters on I(ss.) Moreover, increasing the concentration of intracellular Ca(2+) buffer or intracellular application of the inhibitory CaM-binding peptide (KY9) greatly reduced the phorbol ester-induced depression of I(ss). Taken together, these results suggest that PKC enhances Ca(2+)/CaM-dependent inactivation of the NMDA channel, most likely because of a phosphorylation-dependent regulation of interactions between receptor subunits, CaM, and other postsynaptic density proteins.

[An cephalomectric study on craniofacial structures of Uygur adults with normal occlusion in Xinjiang autonomous region]

OBJECTIVE

To study craniofacial structures of Uygur adults with normal occlusion and establish the standard cephalometric values to evaluate the craniofacial soft and hard tissue structures of normal Uygur adults.

METHODS

Lateral cephalometric radiographs of 93 Uygur adults with normal occlusion (43 men and 50 women) were evaluated with the same standard. Their age ranged from 18 to 25 years old, and they had normal and well-balanced faces without receiving any orthodontical treatment. The lateral cephalogram of each normal adult was traced digitized and measured by the same computer system, then the indexes of craniofacial structures were analyzed by multifactor cluster analysis. 18 typical items were chosen to analyze the characters of the craniofacial structures of Uygur adults with normal occlusion. At the same time, Bayers discriminant analysis was used to identify and evaluate the cluster results.

RESULTS

Uygur adults with normal occlusion were divided into three patterns according to the multifactor cluster analytic results: horizontal tendency pattern (40%), medial pattern (43%) and vertical tendency pattern (17%). When the horizontal tendency pattern was compared with the medial pattern, it showed that the height of S-Go increased (P < 0.05), while the height of ANS-Xi-Pm decreased (P < 0.05); The proportion of S-Go/N-Me increased (P < 0.01). The angle of Ar-Go-Me and Y axis decreased (P < 0.05), which meant that the mandible rotated in the counter-clockwise direction. SN-MP, PP-MP, OP-MP, MP-FH all decreased (P < 0.01), which meant that the SN plane, the PP plane, the occlusion plane and the MP plane all had the trend of hypodivergence. When the vertical tendency pattern was compared with the medial pattern, the height of Ar-Fo decreased (P < 0.01), while the height of ANS-Me increased (P < 0.01); The angle of Ar-Go-Me, Y axis, SN-MP, PP-MP, OP-MP and MP-FH all increased (P < 0.01). These results showed that the mandible rotated in the clockwise direction and the SN plane, the PP plane, the occlusion plane, and the MP plane all had the trend of hyperdivergence. At last, according to the different skeletal patterns, the normal cephalometric values of Uygur adults with normal occlusion were established.

CONCLUSION

Significantly craniofacial structure difference exist in the adults with normal occlusion. Therefore, it is necessary to establish the normal cephalometric values of Uygur adults with normal occlusion according to different skeletal patterns.

[Simultaneous intrusion and retraction of the anterior teeth using a three-piece base arch]

OBJECTIVE

To evaluate the effects of the three-piece base arch on overbite correction of Class II malocclusion.

METHODS

20 patients with high angle, flared incisors were treated using a three-piece base arch appliance. The intrusion force of four upper incisors was adjusted to approximately 50 g. The line of force action was 2 mm distally to the resistant center(RC) and the retraction force was 20 g, the right and left posterior segments were joined by a palatal bar. Cephalograms were taken before treatment (T1) and six months after treatment (T2).

RESULTS

The upper molars moved mesially 0.60 +/- 0.35 mm and the distance of the vertical extrusion was 0.80 +/- 0.52 mm. The distances of the upper central incisor retraction and intrusion were -4.20 +/- 2.12 mm and 3.10 +/- 0.54 mm respectively. The RC of the central incisor retracted -4.12 +/- 1.96 mm and intruded 3.20 +/- 0.66 mm. The axial inclination of the upper incisor-palatal plane changed from 123.21 degrees +/- 4.26 degrees to 116.00 degrees +/- 3.96 degrees.

CONCLUSION

The three-piece segmented approach can effectively intrude and retract the upper anterior teeth for flared incisors and deep overbite.

Cyclic GMP-dependent feedback inhibition of AMPA receptors is independent of PKG

In central neurons, the second messenger cGMP is believed to induce long-term changes in efficacy at glutamatergic synapses through activation of protein kinase G (PKG). Stimulating nitric oxide synthase, activating soluble guanylyl cyclase or elevating concentrations of intracellular cGMP depressed excitatory synaptic transmission in CA1 hippocampal neurons. Unexpectedly, intracellular cGMP depressed responses of AMPA receptors and inhibited excitatory postsynaptic currents in hippocampal neurons independently of phosphorylation. Our findings demonstrate that cGMP's modulation of excitatory transmission may involve a coupling of AMPA channel activity to levels of cGMP.

[Establishment and application of a computerized radiography cephalometrics system]

We have developed a new-typed computerized radiography cephalometrics and prediction system. It includes cephalometrics, growth prediction, orthopedics/orthodontics prediction and profile prediction. In this study, 47 lateral cephalograms were randomly selected to process a reliability test. The results showed the two groups were in agreement on all of the 25 measurement index. The system is easier, quicker and less prone to error than traditional cephalometrics approach. It is convenient for orthodontists.

The general anesthetic propofol slows deactivation and desensitization of GABA(A) receptors

Propofol (2,6-di-isopropylphenol) has multiple actions on GABA(A) receptor function that act in concert to potentiate GABA-evoked currents. To understand how propofol influences inhibitory IPSCs, we examined the effects of propofol on responses to brief applications of saturating concentrations of GABA (1-30 mM). GABA was applied using a fast perfusion system to nucleated patches excised from hippocampal neurons. In this preparation, propofol (10 microM) had no detectable agonist effect but slowed the decay, increased the charge transfer (62%), and enhanced the peak amplitude (8%) of currents induced by brief pulses (3 msec) of GABA. Longer pulses (500 msec) of GABA induced responses that desensitized with fast (tau(f) = 1.5-4.5 msec) and slow (tau(s) = 1-3 sec) components and, after the removal of GABA, deactivated exponentially (tau(d) = 151 msec). Propofol prolonged this deactivation (tau(d) = 255 msec) and reduced the development of both fast and slow desensitization. Recovery from fast desensitization, assessed using pairs of brief pulses of GABA, paralleled the time course of deactivation, indicating that fast desensitization traps GABA on the receptor. With repetitive applications of pulses of GABA (0.33 Hz), the charge transfer per pulse declined exponentially (tau approximately 15 sec) to a steady-state value equal to approximately 40% of the initial response. Despite the increased charge transfer per pulse with propofol, the time course of the decline was unchanged. These experimental data were interpreted using computer simulations and a kinetic model that assumed fast and slow desensitization, as well as channel opening developed in parallel from a pre-open state. Our results suggest that propofol stabilizes the doubly liganded pre-open state without affecting the isomerization rate constants to and from the open state. Also, the rate constants for agonist dissociation and entry into the fast and slow desensitization states were reduced by propofol. The recovery rate constant from fast desensitization was slowed, whereas that from slow desensitization appeared to be unchanged. Taken together, the effects of propofol on GABA(A) receptors enhance channel opening, particularly under conditions that promote desensitization.

[A retrospective study of morphologic basis for the extraction decision in Class II, division 1 malocclusion]

OBJECTIVE

To compare the dentofacial characteristics of persons with Class II, Division 1 malocclusion treated with either an extraction or a nonextraction approach. Such comparison might help identify which parameters influence the extraction decision.

METHODS

Lateral cephalograms were available on 81 cases of Class II, Division 1 malocclusion, 42 were treated with 4 premolar extractions and 39 were treated with non-extraction. The cephalometric analysis of West China University of Medical Sciences and Model Analysis were used,

RESULTS

Patients in the extraction group had larger FMA, FMIA and lower anterior facial height. In the group of extraction, the upper anterior teeth tipped more anteriorly, and the tooth size-arch length discrepancy and the depth of Spee curve were greater significantly. But the saggital discrepancy and soft tissue's profiles had no significant difference between two groups.

CONCLUSION

The stability of the triangle of Tweed, the tooth size-arch discrepancy and the depth of Spee curve were the keys to decide weather extraction or not.

[Effect of energy intake at breakfast on school performance]

In order to examine the effect of energy intake at breakfast on school performance, 151 grade three school children from four classes of two schools were sampled for this study. Children were randomly assigned to breakfast A or B on any given day. They were provided with breakfast with either high or low energy content at school over a period of 5 successive days. The remained foods were collected and weighed. Performance tests including addition, multiplication, number checking, logic, creativity, physical endurance, visual-analogue scales were applied at the third or fourth period of courses in the morning on Tuesday through Friday during the experimental week. The teachers involved in the study were blind to the kind of treatment. No significant effect of energy intake at breakfast on these performance indicators was found in this study.

[The effects of fluoride on the bonding strength of brackets]

OBJECTIVE

To evaluate the effect of using fluoride during and after etching on the bonding strength of brackets.

METHODS

45 extracted human premolar were divided into three groups: Group 1, control, not applying fluoride. Group 2, applying fluoride during etching. Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively and stored in water for 24 hours. Then brackets bonding strength were measured.

RESULTS

The results showed that there was not significant difference among the three groups.

CONCLUSION

Fluoride can be used to prevent enamel white spot.

[Scanning electron microscopy study on different orthodontic methods of using fluoride in enamel white spot prevention]

OBJECTIVE

To determine which method of topical fluoride application could make the enamel uptake more fluoride.

METHODS

12 extracted human premolars were divided into three groups of 4 teeth each: Group 1, control and not applying fluoride; Group 2, applying fluoride during etching; Group 3, applying fluoride after etching. In each group, the teeth were treated with etching and fluoride respectively. The specimens were then examined with scanning electron microscopy.

RESULTS

The results showed that there were more reaction products on the enamel surface of Group 3.

CONCLUSION

There was more fluoride uptake into the enamel treated with fluoride after etching.

Three novel Nicotiana debneyi specific repetitive DNA elements derived from a RAPD marker

The RAPD marker UBC4181050, tightly linked in coupling with the Nicotiana debneyi gene for resistance to black root rot (Chalara elegans Nag Raj and Kendrick; Syn. Thielaviopsis basicola [Berk. and Broome] Ferraris), has been cloned and sequenced. The terminal 10 bases of this RAPD marker exactly match the sequence of the primer UBC418. UBC4181050 was restricted into 6 subfragments of 75, 91, 110, 174, 274, and 336 bp (the accession numbers for these 6 subfragments in the GenBank Data Base are U84217, U84218, U84219, U84220, U84221, and U84222, respectively) by combined restriction with HindIII and RsaI. The entire UBC4181050 marker and its 6 subfragments were used as probes in RFLP analyses. The RFLP analyses were performed on 'Delgold' tobacco (Nicotiana tabacum L.), the tobacco plants (2n = 48) recovered from the somatic hybrids between 'Delgold' and N. debneyi, the 'Delgold' tobacco translocation line carrying the N. debneyi gene for resistance to black root rot, the 'Delgold' tobacco addition lines carrying various N. debneyi chromosomes, and an additional 27 species in the genus Nicotiana. The analyses indicated that UBC4181050 is composed of at least 6 different repetitive DNA elements that are independently interspersed in N. debneyi genomes. Three of them (subfragments of 91, 274, and 336 bp) are N. debneyi specific. The N. debneyi specific repetitive DNA elements are distributed primarily within the taxonomic section (Suaveolentes) to which N. debneyi belongs.Key words: RAPD, repetitive DNA, Nicotiana debneyi, species-specific.

Perioperative cimetidine application modulates natural killer cells in patients with colorectal cancer: a randomized clinical study

Thirty-eight colorectal cancer patients were randomly assigned to treatment group, which took cimetidine in the perioperative period, and control group to which no drug was given. Twenty healthy volunteers served as normal controls. NK cells were measured by immunocytochemical technique. The results showed that NK percentages before treatment in both groups of patients were significantly lower than those in normal controls (P < 0.05). NK cell percentages at admission, before operation, on the 2nd and the 10th postoperative days were 14.84 +/- 4.41, 15.74 +/- 3.75, 17.21 +/- 3.69, 21.05 +/- 4.54, respectively, for the treatment group, and 15.00 +/- 2.77, 13.05 +/- 2.46, 14.21 +/- 2.19, 15.58 +/- 1.68, respectively, for control group. The difference was statistically significant (P < 0.01), suggesting that the perioperative administration of cimetidine could help restore NK cells in colorectal cancer patients.