Would hyaluronic acid-induced mental bone resorption be a concern? A prospective controlled cohort study and an updated retrospective cohort study

BACKGROUND

Hyaluronic acid (HA) is a widely used filler for face contouring and is generally believed to be safe and effective. However, there have been reports of HA-related bone erosion in the chin area without clear scientific data regarding its existence, incidence, and severity. This exploratory study was to evaluate HA-related mental bone resorption through a prospective, controlled, observer-blind, nonrandomized clinical trial and a retrospective cohort study.

METHODS

On the one hand, a prospective, controlled, nonrandomized, single-shot HA-injection clinical trial was conducted. Computed tomographic scans were collected at baseline and at 6-12 months of follow-up for both HA-injection and control groups. On the other hand, an updated retrospective cohort study compared the HA-injection with a blank control group. The primary outcomes composed of three quantitative parameters [bone resorption index (BRI M and BRI N ), bone resorption thickness ratio] and one subjective evaluation index (severity ranking). Information about demographics, complications, and injection volume were also recorded.

RESULTS

From June 2021 to March 2023, 78 patients were prospectively recruited for the study. There was a significant association between HA-injection and bone resorption [BRI M : pre (84.24±8.10%) vs post (79.21±8.70%), P <0.001; BRI N : pre 92.50% (73, 144%) vs 87.99% (63, 132%), P <0.001; bone thickness ratio: HA 24.08% (0, 48%) vs control 0 (0, 17%), P <0.001]. However, there was no difference in large-volume (>1 ml) and small-volume (≦1 ml) injection subgroups [bone resorption thickness ratio: (21.50±10.91%) vs (24.51±11.92%), P =0.350]. The imaging manifestation revealed discernible bone resorption in 35.90% of the patients, with an median bone resorption thickness ratio of 24.08%. Between October of 2019 and March 2023, 95 HA-injection patients (190 semimandibular cases), 95 normal controls were enrolled. The BRI M was significantly lower in the HA-injection group compared to the controls ( P <0.001).

CONCLUSIONS

HA may induce bone resorption in the mentum. Large-scale randomized controlled clinical trial is warranted for further confirmation. Patients should be informed of this potential complication.

The Influence of Extracellular Vesicles Secreted by Dural Cells on Osteoblasts

To explore the influence of extracellular vesicles secreted by dural cells (Dura-EVs) on osteoblasts. Our methodology involves assessing the effects of these EVs at concentrations of 50ug/ml, 100ug/ml, and 200ug/ml on osteoblasts proliferation, differentiation, migration, osteogenesis, and inhibition of apoptosis. We also treated a cranial defect model with injections of these Dura-EVs and monitored the healing rate of cranial defects. Tissue sections were analyzed using Hematoxylin and Eosin (H & E), Masson's trichrome, and immunofluorescence (IF) staining. Our results suggest that Dura-EVs can enhance osteoblasts proliferation, migration, differentiation, and osteogenesis in a dose-dependent manner in vitro. In vivo, Dura-EVs may promote the repair of skull defects. Dura-EVs have an important influence on osteoblasts, our findings shed light on a novel aspect of the dura mater's contribution to cranial osteogenesis.

Preventive Effect of 6-shogaol on D-galactosamine Induced Hepatotoxicity Through NF-?B/MAPK Signaling Pathway in Rats

This analysis aims to see whether 6-shogaol could protect rats against D-galactosamine (D-GalN)-induced Hepatotoxicity. The Wistar rats were divided into four groups (n=6). Group 1 received a standard diet, Group 2 received an oral administration of 6-shogaol (20 mg/kg b.wt), Group 3 received an intraperitoneal injection of D-GalN (400 mg/kg b.wt) on 21st day, and Group 4 received an oral administration of 6-shogaol (20mg/kg b.wt) for 21 days and D-GalN (400 mg/kg b.wt) injection only on 21st day. The hepatic marker enzymes activity, lipid peroxidative markers level increased significantly and antioxidant activity/level significantly reduced in D-GalN-induced rats. 6-shogaol Pretreatment effectively improves the above changes in D-GalN-induced rats. Further, inflammatory marker expression and MAPK signaling molecules were downregulated by 6-shogaol. These findings showed that 6-shogaol exerts hepatoprotective effects via the enhanced antioxidant system and attenuated the inflammation and MAPK signaling pathway in D-GalN-induced rats.

Successful Treatment and Long-term Follow-up of Parry-Romberg Syndrome with Anterolateral Thigh Adipofascial Flap

BACKGROUND

Anterolateral thigh (ALT) adipofascial free flap transfer is a frequently used method to reconstruct the facial symmetry and restore facial soft-tissue contour in PRS patients. While its long-term prognosis and patient outcomes assessment are still lack of understanding.

METHOD

The authors report their treatment experience in 42 patients between 2001 and 2017 using microsurgical free anterolateral thigh adipofascial flap transfer. The long-term follow-up results and final reconstructive outcomes were evaluated.

RESULTS

A total of 42 patients were included. The follow-up ranged from 5 to 21 years. All patients were satisfied with the surgery. Photographic evaluation revealed significant enhancement of postoperative appearance. Numbness or hypesthesia of the local area was the most common symptom in the long-term follow up.

CONCLUSION

This study has evaluated the long-term treatment results of Parry-Romberg disease with microsurgery using ALT free flap in our department. Over 20 years' experience and the significant enhancement of the overall appearance indicate a long-lasting, excellent outcome.

Association between Intrinsic Capacity and Sarcopenia in Hospitalized Older Patients

OBJECTIVES

This study aimed to clarify the association between intrinsic capacity (IC) and sarcopenia in hospitalized older patients.

DESIGN

A cross-sectional study.

SETTING

Hospital-based.

PARTICIPANTS

This study included 381 inpatients aged ≥ 60 years (225 men and 156 women).

MEASUREMENTS

IC was evaluated in five domains defined by the World Health Organization: cognition (Mini-Mental State Examination), locomotion (Short Physical Performance Battery test), vitality (Short-Form Mini Nutritional Assessment), sensory (self-reported hearing and vision) and psychological (5-item Geriatric Depression Scale) capacities. IC composite score (0-5) was calculated based on five domains, with lower scores representing greater IC. Sarcopenia was defined in accordance with the criteria recommended by the Asian Working Group for Sarcopenia (AWGS) 2019. Multiple linear and logistic regressions were performed to explore the associations between IC composite score and IC domains with sarcopenia and its defining components.

RESULTS

The mean age of 381 patients included was 81.95±8.42 years. Of them, 128 (33.6%) patients had sarcopenia. The median IC composite score was 1 (1, 2). Cognition, locomotion, vitality, sensory and psychological capacities were impaired in 22.6%, 63.5%, 18.9%, 27.3% and 11.3% of patients. Multiple linear regression analyses showed that favorable IC domain scores in cognition, locomotion and vitality were associated with a stronger handgrip strength. A higher vitality score was associated with a greater appendicular skeletal muscle mass index (ASMI), and a higher locomotion score was associated with a greater gait speed. The multiple logistic regression analysis showed that only vitality impairment was associated with sarcopenia. A higher IC composite score was associated with higher risks of sarcopenia, as well as low ASMI, handgrip strength and gait speed.

CONCLUSION

This study indicated that a more serious impairment of IC was associated with a greater risk of sarcopenia. Vitality was the domain most strongly associated with sarcopenia. IC may be employed to detect and manage sarcopenia.

Redefining Mandibular Sub-units: The "ABC" Classification and Surgical Strategies for Lower Face Contouring

BACKGROUND

In east Asia, lower face contouring surgeries including reduction mandibuloplasty and genioplasty are the most popular aesthetic craniofacial surgeries. Conventional selection of surgical strategies mainly relied on the visual judgment of the mandibular angle, without overall assessment of the mandibular sub-units. Furthermore, only a few studies offered quantitative assessment of the mandibular shape.

METHODS

From 2010 to 2021, 1241 patients diagnosed with square faces and received customized lower face contouring surgeries by the senior author were reviewed and analyzed to propose an "ABC" classification system for facilitating surgical planning.

RESULTS

Among them, 998 (80.42%) received bilateral mandible reshaping, 155 (12.49%) underwent bilateral mandible reshaping combined with genioplasty, and 88 (7.09%) received asymmetric mandible reshaping. A modified classification system composed of three critical parameters (height, morphology/thickness, divergence) in three aesthetic zones (mandibular angle, mandibular body, chin) was proposed based on quantitative summarization of the CT database and the senior author's 12-year experience. The way to facilitate surgical planning with this classification was demonstrated.

CONCLUSIONS

This modified classification system ushered a decision-making process that prioritized several critical measurements and proposed an operative planning form. Meanwhile, it can also be cooperated into the three-dimensional virtual surgical plan.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Study on the difference of osteogenesis and Notch signaling pathway expression in biphasic calcium-phosphorus ceramic granule materials with different microstructure

Different microstructures including micropore diameter, micropore volume, and micropore area of biphasic calcium phosphate (BCP, hydroxyapatite: β-tricalcium phosphate = 8:2) ceramics granules were obtained by varying their sintering temperatures. Sprague-Dawley rat bone marrow-derived stem cells (BMSCs) were co-cultured with BCPs in vitro study and the BMSCs showed different degrees of proliferative activity under the influence of three materials. Cell proliferation and vitality were assessed. Three kinds of BCPs were implanted in the dorsal muscle of beagle dogs. At 1, 2, and 3 months, histological analyses were conducted to estimate the rate of osteogenesis. Expression of Notch pathway genes and osteogenic-related genes were detected by quantitative real-time polymerase chain reaction (q-rtPCR). The proportion of osteogenesis area increased to:48.75 ± 4.20%, 29.48 ± 1.55%, and 26.58 ± 3.86% at 3 months after the implantation (1050, 1150, 1250). Significant differences were observed in the upregulation of Notch pathway genes among different BCPs. BCPs with different micropore diameters have different ectopic osteogenesis effects and led to up-regulation of the Notch signaling pathway genes to different extents.

Facial Contour Refining after Surgery-First SSRO with Computer-Assisted Design in East Asians

BACKGROUND

Surgery-first sagittal split ramus osteotomies (SF-SSRO) are an effective treatment for patients with dental malocclusion. However, some patients with mandibular prognathism usually have facial deficiencies which cannot be corrected completely after orthognathic surgery. These are not accepted because the remaining facial contours are in disharmony.

METHODS

Twenty-five patients, who were unsatisfied with their appearances after SF-SSRO and orthodontics, were included. The preoperative CTs were used to investigate patients for facial deformity. To achieve a harmonious facial contour, mandible long-curve osteotomy/mandible U-shaped osteotomy, genioplasty or facial autologous fat grafting was selected depending on patients' contour deformities with the assistance of CAD.

RESULTS

Among the patients who underwent osteotomy, the gonial angle was improved from 111.16° ± 9 to 111.58° ± 9.06 after SF-SSRO because of distal fragment setback and rotation. After facial refine surgery, the gonial angle was significantly increased to 121.69°±2.41 (p < 0.05). And the mandibular width was decreased from 11.29 cm ± 0.44 to 10.45 cm ± 0.39 (p < 0.05) after mandibular outer plate griding. All patients were shown no signs of infection, massive bleeding, and osteonecrosis in the early stage. After follow-up time, they were all satisfied with their results and most of them recovered from lip numbness.

CONCLUSIONS

This study indicated the clinical feasibility of two-stage orthognathic and facial bone contouring surgery for the treatment of dentofacial deformities. Two-stage facial contouring surgery can provide esthetic improvement for more accuracy in refining the facial contour.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A Modified Procedure for Single-eyelid Asian Females with Lacrimal Gland Prolapse: Lacrimal Gland Reposition combined with Fat Transposition in Double-eyelid Operation

BACKGROUND

The awareness and treatment of lacrimal gland prolapse (LGP) have been primarily improved with a further understanding of lateral eyelid bulging over the decades. However, for Asian single-eyelid females with LGP, a tailor-made procedure applicable to their comparatively young puffy eyes is needed.

METHODS

This is a retrospective study. From Jan. 2009 to Jan. 2019, two hundred and three Asian single-eyelid females with LGP, who met the inclusion criteria, underwent double-eyelid surgeries and adjunctive lacrimal gland repositions with preaponeurotic fat transposition. Pertinent demographics, complications, pre-and post-operative photography were collected.

RESULTS

A total of 167 patients completed the 4-24 months' follow-up (average: 16.3 months). One hundred and thirty-two cases (79.0%) were diagnosed as LGP preoperatively, and the rest (35/167, 21.0%) were diagnosed intraoperatively. All patients (average: 28.4 years old) received modified blepharoplasty. Postoperative symptoms involving local mild pain (2.9%, 5/167), upper eyelid tightness (3.6%, 6/167), and moderate epiphora (9.0%, 15/167) were all recovered spontaneously within one month. Prolapse recurrence and severe complications such as dry eye syndrome were not observed.

CONCLUSIONS

We proposed a modified procedure to enhance the diagnosis and treatment of LGP during Asian blepharoplasty. The lacrimal gland suspension and fat transposition assured the cosmetic outcome for selected young, puffy Asian eyes. The supratarsal creases were satisfactory, and the complication rate was low. Furthermore, the rearrangement of preaponeurotic fat smoothed the contour transition and preserved the orbital volume. Therefore, this is a safe and effective technique worth recommending.

Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices

We investigated changes in concentrations of ADP (adiponectin), LEP (leptin), BHBA (beta-hydroxybutyric acid), NEFA (non-esterified fatty acid), Glucose (Glu) and INS (insulin) in serum of healthy perinatal dairy cows and cows with ketosis. Twenty-one healthy cows and seventeen cows with ketosis from a herd of a total 60 Holstein cows (near dry period i.e. 56 days antepartum) were selected. Blood was collected through the tail vein every 7 days, from 56 day antepartum to 56 day postpartum. Serum ADP, LEP, BHBA, NEFA, Glu, and INS concentrations were determined, and ketosis was diagnosed through serum BHBA (≥1.2 mmol/L). We showed the concentration of serum adipokines and energy balancing indices were stable during antepar- tum period. However, ADP concentration increased while LEP decreased, and there were a significant increase in cows with ketosis compared to that of in healthy cows. Serum BHBA and NEFA concentrations increased significantly at first, and then gradually decreased in both healthy cows and cows with ketosis. However, cows with ketosis showed higher concentrations of BHBA and NEFA which restored later. The serum concentration of Glu in both healthy dairy cows and cows with ketosis showed a decreasing trend. INS concentration in healthy cows was decreased while it was increased in cows with ketosis. The results reflect the extent of hypo- glycemia and lipid mobilization postpartum, suggest IR exists in cows with ketosis while serum ADP and LEP might play roles in the development of ketosis.

Effect of hydroxyethyl cellulose soluble hemostatic gauze on hemostasis in facial contouring surgery

BACKGROUND

In facial contour surgery, due to the narrow field of vision in the oral approach and the abundant blood supply to the maxillofacial area, hemostasis is not easy. The purpose of this study was to evaluate the hemostatic effect of soluble hemostatic gauze.

METHODS

We organized a prospective randomized study of 282 patients receiving facial contouring surgery (4 types of procedures in total) during 2016.1.1 to 2018.12.30. For each type of procedure, patients were randomly divided into study group (received hemostatic gauze) and control group (received sterile gauze). Two groups were compared for each type of procedure regarding 5 major perioperative variables: intraoperative blood loss, operation time, 24-hour postoperative drainage volume, total postoperative drainage volume, and postoperative drainage time. Correlation between variables was analyzed.

RESULTS

Compared with control group, the study group had higher amount of intraoperative blood loss in mandibular angle ostectomy (MAO) (P < .01) and mandibular angle-body-chin curved ostectomy procedures (P < .05), less total postoperative drainage volume in MAO (P < .01) but not in malarplasty with MAO and partial masseter muscle resection along with MAO procedures. No significant difference was observed between respective study and control groups regarding operation time, 24-hour postoperative drainage volume, and postoperative drainage time in any of the 4 types of surgery. In all 4 types of procedures, a strongly positive correlation was observed between total drainage volume and 24-hour drainage volume in both the study and control groups (r: 0.88-0.97, P < .01).

CONCLUSION

The effect of hydroxyethyl cellulose soluble hemostatic gauze on hemostasis in facial contouring surgery is associated with the type of surgery, which can reduce the risk of postoperative bleeding in MAO. However, for surgery with relatively large amount of intraoperative and postoperative bleeding, the hemostatic gauze had a limited postoperative hemostasis efficacy, which needs further evaluation.

[Influence of different sintering temperatures on mesoporous structure and ectopic osteogenesis of biphasic calcium phosphate ceramic granule materials]

Objective

To detect the difference in the osteogenesis ability of biphasic calcium phosphate (BCP) ceramic granular materials with different mesoporous diameters prepared at different sintering temperatures through in vivo and in vitro experiments, so as to provide evidence for screening BCP materials with better clinical application parameters.

Methods

Three kinds of BCP (materials 1, 2, 3) were prepared by mixing hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) at a ratio of 8∶2 and sintered at 1 050, 1 150, and 1 250℃ for 3 hours, respectively. The internal porosity and the diameter, volume, and area of the mesopore were measured by Brunauer-Emmett-Teller test (BET); the composition of the material was evaluated by X-ray diffraction (XRD); the microscopic surface morphology of the material was observed by scanning electron microscopy (SEM). The 3rd generation bone marrow mesenchymal stem cells (BMSCs) from Sprague-Dawley rats were co-cultured with the materials 1, 2, and 3 for 7 days in vitro respectively (groups A, B, and C), and the cells adhesion on the materials was observed by SEM and phalloidine staining, respectively. Cell proliferation activity was measured by cell counting kit 8 method. In vivo, 9 muscle bags were made in dorsal muscles of 9 beagles, respectively. The muscle bags were randomly divided into 3 groups (3 per beagle in each group) and materials 1, 2, and 3 were placed into the muscle bags of groups A, B, and C, respectively. After 1, 2, and 3 months of operation, 3 beagles were anesthetized and the samples were stained with HE, Masson, and Safranin, and the bone formation area ratio in the BCP gap was calculated. Real-time fluorescence quantitative PCR (qRT-PCR) was performed to detect the expressions of bone-related genes [including alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OC)].

Results

The BET test showed that with the increase of sintering temperature, the internal porosity of the particles did not change significantly, but the diameter, volume, and area of the mesopores gradually decreased. The XRD detection showed that the XRD waves of HA and β-TCP could be seen in all 3 kinds of materials; SEM showed that there were widely distributed macropores on the surface of 3 kinds of BCPs, and the interpores connected with the others. In vitro, BMSCs adhered and proliferated on the surfaces of 3 kinds of BCPs, and the cell biocompatibility of the materials in groups B and C was better than that in group A. In vivo, obvious osteoid tissue deposition could be observed in the intergranular space of 3 kinds of BCPs from 2 months after implantation. The bone formation area ratio of each group increased with time. The bone formation area ratio in group A was significantly higher than that in groups B and C at 2 and 3 months after implantation, and in group A than in group B at 1 month ( P<0.05). qRT-PCR showed that the expressions of osteogenic related genes peaked at 2 months in group A, and gradually increased with time in groups B and C. The relative expressions of ALP and OPN mRNAs in group A were significantly higher than those in groups B and C at 1 month after implantation, the relative expression of OC mRNA in group A was significantly higher than that in groups B and C at 2 months after operation, the relative expression of ALP mRNA in groups B and C and the relative expression of OPN mRNA in group B were significantly higher than those in group A, all showing significant differences ( P<0.05); there was no significant difference in the relative expression of each gene among the other groups at each time point ( P>0.05).

Conclusion

The mesoporous diameter of BCP decreases with the increase of sintering temperature. Different mesoporous diameters lead to different ectopic osteogenesis of BCP materials. BCP material with mesoporous diameter of 12.57 nm has better osteogenic ability which can activate the osteogenic gene earlier. The mesoporous diameter is expected to be an adjustable index for optimizing the osteogenic capacity of BCP materials.

Chicory fibre improves reproductive performance of pregnant rats involving in altering intestinal microbiota composition

AIM

Chicory fibre (CF) is rich in fructan, which always functions as a quality dietary fibre source during mammalian pregnancy; however, its effect on reproductive performance remains unclear.

METHODS AND RESULTS

40 pregnant SD rats were randomly allotted to receive one of four diets: basal diet (control group), basal diet + 5% CF, basal diet + 10% CF, and basal diet + 15% CF, respectively. We found that CF significantly increased the number born alive and total litter birth weight (P < 0·05), increased the expression of intestinal tight junction proteins, mucins and antimicrobial peptides, accompanied by the increase of villi height and the decrease of crypts depth of pregnant SD rats (P < 0·05). We also observed that CF markedly increased the acetic acid, propanoic acid, butyric acid and total SCFAs concentrations in caecum contents and promoted the expression of SCFAs-related receptors (P < 0·05). Notably, rats fed CF increased the relative abundance of Bacteroidetes (P < 0·001), decreased the relative abundance of Firmicutes and Proteobacteria, while markedly lowered the Firmicutes/ Bacteroidetes ratio (F/B ratio) (P < 0·05). Intriguingly, the number born alive and total litter birth weight were positively correlated with some probiotics and negatively correlated with other harmful bacteria by Pearson correlation analysis.

CONCLUSION

Collectively, CF can enhance intestinal barrier function and maintain intestinal health, and may improve reproductive performance by altering intestinal microbiota composition.

SIGNIFICANCE AND IMPACT OF THE STUDY

Adding suitable dietary fibre to the diet can improve the reproductive performance of sows. Indeed, there exist various problems in the application of traditional dietary fibres, including high insoluble fibre content and anti-nutritional factor level, and mycotoxin contamination. This study demonstrates that dietary CF supplementation improves reproductive performance and intestinal health. Thus, CF can be applied in pregnancy animals as a new dietary fibre additive in animal husbandry.

What happens to an acellular scar matrix after implantation in vivo? A histological and related molecular biology study

It has been established that scar acellular matrices (AMs), which allow cell proliferation, have similar characteristics. The aim of this study was to investigate the repair effect of scar AMs on animals, thus providing a reference for clinical application. Selected mature and immature scar AMs were implanted into animals, and then a negative control group was set for comparison. The effect of scar AMs on wound healing was observed through tissue staining, RT-qPCR, and immunohistochemistry. The materials showed milder inflammation and faster extracellular matrix (ECM) deposition than the negative control group. The ECM deposition and new vessels increased over time. However, the arrangement of ECM in mature scar AM was more regular than in immature scar AM and the negative control group, and more new vessels grew in the mature scar AM group than in the immature scar AM group and negative control group over the same period. The transforming growth factor-β level was elevated at one month, two months, and six months. COLA1 and vimentin levels all peaked at six months. Matrix metalloproteinase and TIMP1 were also elevated at different months. Collectively, scar AMs can effectively promote wound healing and vascularization. Mature scar AMs have a better regeneration effect.

Simultaneous surgery of mandibular reduction and impacted mandibular third molar extraction: A retrospective study of 65 cases

A considerable number of patients with prominent mandibular angle have mandibular third molar impaction that needs surgical removal. Mandibular reduction is a popular and effective surgery to correct prominent mandibular angle, but it has been rarely performed simultaneously with impacted third molar extraction. In order to decrease the number of operations and suffering of patients, safely performing these 2 operations together is necessary and important. From January 2016 to June 2018, patients received mandibular reduction and impacted mandibular third molar extraction together were retrospectively reviewed. Forty-seven patients receiving long-curve mandibular reduction (n = 12) or simple mandibular reduction (n = 35) were included in this study. A total of 65 impacted mandibular third molars were extracted during mandibular reduction. One patient had hematoma within facial soft tissue which reabsorbed spontaneously. Seven patients who underwent long-curve mandibular reduction reported transient inferior lip numbness for several weeks. No infection or poor wound healing was reported. No immediate or delayed mandibular fracture occurred. All the patients were satisfied with both the aesthetic result of mandibular reduction and the unnecessity of receiving a secondary surgery to extract the impacted third molar. Simultaneously performing mandibular reduction and impacted mandibular third molar extraction can effectively reduce the number of operations and patients' suffering. It is also safe with adequate pre-op assessment, professional surgical knowledge, proper use of surgical instruments, meticulous surgical procedures, and correct post-op care.

Relationship of adiponectin, leptin, visfatin and IGF-1 in cow's venous blood and venous cord blood with calf birth weight

The Intrauterine fetal development process is complicated and affected by many regulating factors such as maternal nutritional status, transcription factors and adipokines. Adipokines are kinds of active substances secreted by adipose tissue, including more than 50 kinds of molecules. To explore the correlation between calf birth weights and adipokines including adiponectin, leptin, visfatin, and IGF-1 in cows venous and venous cord blood. Fifty-four healthy multiparous Chinese Holstein cows were used; in which, cows with a calf weight less than 40 kg were included in group A (n=9); those with a calf weight between 40 kg~45 kg were included in group B (n=25) and ≥45 kg were included in group C (n=20), venous blood and cord venous blood was collected. An ELISA kit was used to evaluate the concentration of adiponectin, leptin, visfatin, and IGF-1, correlations between index-index and index-calf birth weight were analysed. In both cows venous and cord venous blood, adiponectin, leptin, visfatin, and IGF-1 levels were significantly correlated with each other (p⟨0.01), and levels of these adipokines in venous blood were significantly higher than cord venous blood (p⟨0.01). Adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were positively correlated with calf birth weights, and significantly correlated with calf birth weights respectively (p⟨0.01). Our study showed that adiponectin, leptin, and IGF-1 were found in venous blood and cord venous blood, and adiponectin, leptin, and IGF-1 in venous and cord venous blood potentially inter-regulated each other; adiponectin, leptin, and IGF-1 in venous blood were not significantly correlated with calf birth weights, while adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were significantly correlated with calf birth weights, respectively.

Effect of butein and glucose on oxidative stress and p38 activation marker in non-small cell lung cancer cell

INTRODUCTION

Tumor microenvironment is known to alter the anticancer drug efficiency. One of the factors that get altered in cancer microenvironment is glucose concentration. Butein, an active principle from plant, known to have anticancer effect against different types of tumor. The objective of the study is to determine the effect of butein on glucose exposed non-small cell lung cancer cells (NSCLCCs).

METHODS

The current study deals with the effect of butein (6.25-50μM) on NSCLCCs treated with different concentrations (0-40 mM) of glucose.

RESULTS AND DISCUSSION

Glucose concentration, 0 mM and 40 mM, was found to be lethal at 72 h. Viable cell numbers were statistically increased in 5-mM, 10-mM, and 20-mM glucose-treated cells. Butein at 12.5 µM inhibits (p < 0.05) glucose-induced cell proliferation. Butein inhibits glucose-induced proliferation through DNA damage and oxidative stress. Mitochondrial reactive oxygen species (ROS) level was elevated in 20-mM glucose-treated cells when compared to 5-mM glucose-treated cells, whereas butein treatment further increases glucose-induced mitochondrial ROS. Pharmacological inhibitor of glycolysis, such as 2-deoxy glucose (2-DG), was found to inhibit (p < 0.05) glucose-induced cells proliferation. Furthermore, 2-DG and butein showed synergistic anticancer effect. Butein treatment increases p38 phosphorylation. Inhibition of p38 phosphorylation and antioxidant pretreatment partially revert the glucose-induced cell proliferation. However, inhibition of p38 phosphorylation combined with antioxidant pretreatment completely reverts the anticancer effect of butein. The present study concludes through the evidence that butein could serve as a potential anticancer compound in tumor microenvironment.

Toxicity of functionalized multi-walled carbon nanotubes on bone mesenchymal stem cell in rats

Carbon nanotubes (CNTs) are promising biomaterials in the medical field, especially in tissue engineering of bone. However, the use of CNTs is largely confined by its unfavorable solubility and toxicity. To improve solubility and biocompatibility of CNTs, functionalization has been proven to be an effective strategy. Although various functionalized CNTs have been extensively studied, only few CNTs have the desired qualities. We compared the toxicity of several promising functionalized multi-walled carbon nanotubes (MWCNTs) on rat bone-marrow derived stem cells (BMSCs). Cell experiments showed that while acid oxidation (AO)-MWCNTs and Raw-MWCNTs exhibited significant toxicity on BMSCs, polyethylene glycols (PEG)-MWCNTs and hydroxyapatit (HA)-MWCNTs had favorable biocompatibility and a trivial effect on BMSCs. Possible mechanisms for the cytotoxicity on BMSCs included mitochondrisome and deoxyribonucleic acid damage, increased oxidative stress and damaging of cellular membranes. Our data indicated that PEG-MWCNTs and HA-MWCNTs may be promising materials for bio-related applications.

Using the Reversed Temporal Island Flap to Cover Small Forehead Defects from Titanium Mesh Exposure After Cranial Reconstruction

BACKGROUND

Skin ulcers and alloplastic implant exposure are intractable complications that arise after cranial defect reconstruction. Many methods have been used to repair these defects, including skin grafting, local flaps, and free flaps; however, in most cases, alloplastic implants must be removed to control infections. Here, we describe the use of a reversed temporal island flap to repair exposed titanium mesh without removing it.

METHODS

Eight cases of skin and titanium mesh exposure were included from 2010 to 2015. A preauricular flap pedicled on the reversed superficial temporal artery was designed to repair forehead defects. The titanium mesh was retained, resterilized, and reimplanted.

RESULTS

Flaps were survived completely, and the titanium meshes were reimplanted with no complications. The results were aesthetically and functionally sufficient, with minimal donor-site morbidity in all cases during the 10- to 24-month follow-up period.

CONCLUSIONS

The described method is easy to design and perform. The flap has a reliable blood supply to help fight infection. The titanium mesh is preserved completely, avoiding a second cranioplasty.

TGF-β1 Induces Polypyrimidine Tract-Binding Protein to Alter Fibroblasts Proliferation and Fibronectin Deposition in Keloid

Human dermal fibrotic disease keloid has been a clinical challenge because of its tumour-like growth and the lack of effective therapy. Dysregulated alternative splicing events have been demonstrated in tumours and fibrosis. In the current study, for the first time, it was demonstrated that the splicing regulator polypyrimidine tract-binding protein (PTB), which plays a pivotal role in tumour proliferation, invasion and metastasis, is overexpressed in keloid tissues and fibroblasts. Additionally, TGF-β1 upregulated the expressions of PTB and its upstream regulator, C-MYC, in keloid fibroblasts. Furthermore, we suppressed PTB using siRNA in keloid fibroblasts and in a keloid xenograft nude mouse model. PTB knockdown significantly slowed the proliferation of keloid fibroblasts and accelerated the regression of transplanted keloid tissues, which was accompanied by a shift in the alternative splicing of USP5 and RTN4. Moreover, when PTB was suppressed, there was a reduction in excessive deposition of FN1 and COL3A1 in transplanted keloid tissues. However, only FN1 was downregulated in keloid fibroblasts that were cultured in media supplemented with TGF-β1. Our study provides evidence for the role of PTB in keloid pathophysiology and offers a novel therapeutic target for keloids. Most importantly, the role TGF-β1 regulation of PTB may provide new insights into the mechanisms underlying inflammatory cytokine-induced fibrosis.

Risperidone-induced topological alterations of anatomical brain network in first-episode drug-naive schizophrenia patients: a longitudinal diffusion tensor imaging study

BACKGROUND

It remains unclear whether the topological deficits of the white matter network documented in cross-sectional studies of chronic schizophrenia patients are due to chronic illness or to other factors such as antipsychotic treatment effects. To answer this question, we evaluated the white matter network in medication-naive first-episode schizophrenia patients (FESP) before and after a course of treatment.

METHOD

We performed a longitudinal diffusion tensor imaging study in 42 drug-naive FESP at baseline and then after 8 weeks of risperidone monotherapy, and compared them with 38 healthy volunteers. Graph theory was utilized to calculate the topological characteristics of brain anatomical network. Patients' clinical state was evaluated using the Positive and Negative Syndrome Scale (PANSS) before and after treatment.

RESULTS

Pretreatment, patients had relatively intact overall topological organizations, and deficient nodal topological properties primarily in prefrontal gyrus and limbic system components such as the bilateral anterior and posterior cingulate. Treatment with risperidone normalized topological parameters in the limbic system, and the enhancement positively correlated with the reduction in PANSS-positive symptoms. Prefrontal topological impairments persisted following treatment and negative symptoms did not improve.

CONCLUSIONS

During the early phase of antipsychotic medication treatment there are region-specific alterations in white matter topological measures. Limbic white matter topological dysfunction improves with positive symptom reduction. Prefrontal deficits and negative symptoms are unresponsive to medication intervention, and prefrontal deficits are potential trait biomarkers and targets for negative symptom treatment development.

Analysis of Characteristics Similar to Autoimmune Disease in Keloid Patients

BACKGROUND

Keloid is a fibrotic skin disease for which immune cell infiltration is a primary pathological hallmark. Meanwhile, in autoimmune diseases, triggering of the inflammation response can lead to tissue injury and subsequent organ fibrosis. When the skin is involved in autoimmune disease, skin fibrosis such as that seen in scleroderma can occur. In this study, we propose that keloid possesses features of autoimmune disease.

METHODS

To verify whether keloid possesses features of autoimmune disease, immune cell infiltration and immune complex deposits were detected with immunohistochemical staining and immunofluorescence, respectively, in keloid and normal skin tissues. A routine antinuclear antibody profile was tested in sera from 28 keloid patients and 28 healthy controls. Lastly, the anti-hnRNPA2B1 autoantibody in sera was evaluated by enzyme-linked immunosorbent assay.

RESULTS

The numbers of CD1α(+) Langerhans cells, CD3(+) T lymphocytes, CD68(+) macrophages, and CD20(+) B lymphocytes increased in keloid tissues compared to normal skin. IgA, IgM, C3, and C1q deposits were found in keloid tissues but not in normal skin, while anti-hnRNPA2B1 levels in sera from keloid patients were elevated.

CONCLUSION

The above findings suggest that keloids have some characteristics that are similar to autoimmune disease and might be mediated by autoimmune responses.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Structural and biomechanical properties of accelular dermal matrix derived from human scar tissue]

OBJECTIVE

To explore the structural and biomechanical properties of acellular dermal matrix (ADM) of human scar tissue.

METHODS

Randomly choose 8 human mature scar tissue, 8 human hypertrophic scar tissue, and 4 normal human tissue as experimental samples respectively. Then 0.5 mm split-thickness skin grafts were obtained by drum-type scalpel, further acellularized by 2.5 g/L trypsin-0.5% TritonX-100. Structural analyses were performed by macroscopic observation, hematoxylin and eosin histological staining and scanning electron microscope. Then human epithelial stem cells were inoculated, cultured on those materials and observe their adhesive properties. Finally the biomechanical properties of ADM were analyzed through the detection of stress-strain relation, stress relaxation, creep and ultimate stress strength to distinguish different origins.

RESULTS

Prepared ADM was milky white in color despite their distinct origins, physiological and mature scar tissue derived ADM was soft and flexible in texture while ADM from hypertrophic scar showed a more tenacious character. Optical microscopic and electron microscopic analyses showed no sign of visible cellular structures. ADM from physiological group had relatively homogeneous and inerratic collagenous fibers, ADM from hypertrophic group presented with fibers of various diameters and arrayed in a compact and disordered manner. ADM from mature scar tissue possessed traits between the other two groups. Adhesion growth could be observed 2 weeks after inoculating human epithelial stem cells on ADM and cells grew in a cohesive fashion on ADM both from normal skin and mature scar tissue and in an adhesive fashion on hypertrophic scar tissue ADM. Stress-strain β value (3.024 ± 0.413, 2.595 ± 0.443, 2.590 ± 0.366), creep slope (0.018 ± 0.003, 0.019 ± 0.009, 0.023 ± 0.010) and ultimate stress strength (8.971 ± 2.434, 11.011 ± 1.492, 15.567 ± 2.931) of ADM showed no significant differences in hypertrophic scar, mature scar and normal skin tissues (all P > 0.05). ADM from mature scar and normal skin tissue showed no differences in stress-strain stretch ratio (0.238 ± 0.083 vs 0.291 ± 0.048), relaxation slope (-0.041 ± 0.009 vs -0.047 ± 0.008), total relaxation (0.775 ± 0.194 vs 0.968 ± 0.211) or total creep (0.033 ± 0.022 vs 0.049 ± 0.020) (all P > 0.05). However, the above related indices of ADM from hypertrophic scar tissue (0.188 ± 0.036, -0.033 ± 0.006, 0.481 ± 0.058, 0.020 ± 0.005) were significantly lower than those from normal tissue (all P < 0.05).

CONCLUSIONS

No significant differences exist between mature scar and normal skin tissues derived ADM both in structural and biomechanical properties. However ADM from mature scar appears to be superior in biomechanical properties than hypertrophic scar derived ADM so that it may become a replacement for original dermis in wound repair.

An electric-field assisted growth control methodology for integrating ZnO nanorods with microstructures

The growth control of ZnO nanorods bridging over two microelectrodes in a three-electrode structure (the top cathode and anode, and the bottom gate) was realized using a wet chemical method with the assistance of an electric field generated by applying AC sine wave power on the top electrodes and a DC voltage on the bottom gate. A numerical control model for controlling the growth position, direction and density of ZnO nanorods on the microstructure was established based on the simulation of the electric-field distribution around the microstructures. The three input parameters in the numerical control model were defined as the peak-to-peak voltage of the AC sine wave (x1), the frequency of the AC sine wave (x2) and gate voltage (x3). Moreover, five output parameters (y1, y2, y3, y4, y5) in the model were defined as the electric field intensities at specific points on the electrodes to characterize the growth rate, direction, position and morphology of the ZnO nanorods integrated with the microelectrodes. The relationship between the defined outputs and inputs were established using 3(rd) polynomial fitting, which served as the numerical control model for the prediction of nanorod growth. The experimental results validated that growth control methodology provides us with an effective approach to integrate ZnO nanorods into devices.

Measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the reaction (3)He(↑)(e,e')X

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3)He(↑)(e,e')X on a polarized (3)He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7<W<2.9  GeV, 1.0<Q(2)<4.0  GeV(2) and 0.16<x<0.65. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-(3)He cross-section ratios. The measured neutron asymmetries are negative with an average value of (-1.09±0.38)×10(-2) for invariant mass W>2  GeV, which is nonzero at the 2.89σ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

[Experimental study of skin wound healing with epidermal stem cells from human hypertrophic scar in nude mice]

OBJECTIVE

To investigate the effect of epidermal stem cells from human hypertrophic scar (HS-ESCs) on the skin wound healing in nude mice.

METHODS

40 mice were randomly divided into two groups as experimental group (n = 20) and control group (n = 20). Wounds, 1 cm in diameters, were made on every mouse back. The wounds were treated with HS-ESCs and erythromycin ointment in experimental group, or only with erythromycin ointment in control group. The wound healing was observed during the following 14 days. The expression of collagen-I, collagen-III, epidermal growth factor (EGF), fibroblast growth factor (FGF2) , transforming growth factor (TGFbeta1, and TGFbeta2) were studied.

RESULTS

The wound healing time in the experimental group was (20.8 +/- 0.84) d, which was (25.6 +/- 0.89) d in the control group. HE staining revealed that the extent of vascularization in the experimental group was 11.60 +/- 0.55, while it was 8.04 +/- 0.33 in the control group. Immunochemistry analysis showed the expression of collagen-I, collagen-III, EGF, FGF2, TGFbeta1, and TGFbeta2 in the experimental group were significantly higher, compared with those in control group (P < 0.05).

CONCLUSION

HS-ESCs may promote wound healing through enhancement of the vascularization of the wound tissue and the expression of growth factors.

[Comparison of biological characteristics and quantity of epidermal stem cells from hypertrophic scar skin and normal skin of human beings]

OBJECTIVE

To compare the biological characteristics of epidermal stem cells (ESCs) from hypertrophic scar and normal skin.

METHODS

Epidermal stem cells were separated, enriched and adhered from 20 hypertrophic scars (scar group) and 20 normal skins (control group). The morphology and growth characteristics of primary epidermal stem cells were observed. The absorbance (A) values of expression of Keratin 19, nucleoprotein p63 and integrin β1 were tested by Western blot. And the genes of Oct-4 and Nanog were tested by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Flow cytometry was used to examine the markers of integrin CD29, integrin CD49f and Keratin 19 of ESCs.

RESULTS

The primary cultured cells showed the similar shape and growth curve. By comparing the epidermal stem cells from scar groups and control groups, the absorbance values of the expression of Keratin 19, nucleoprotein p63 and integrin β1 were 860 ± 4, 712 ± 3, 422 ± 6 and 862 ± 3, 707 ± 9, 413 ± 6 (all P > 0.05). The expression values of Oct-4, Nanog were (7.79 ± 0.44)×10(-4), (5.96 ± 0.36)×10(-4) and (7.93 ± 0.29)×10(-4), (6.06 ± 0.35)×10(-4) (all P > 0.05). Percentages of positive cells expressing CD29, CD49f and Keratin 19 were (97.3 ± 0.7)%, (94.6 ± 1.1)%, (92.5 ± 0.8)% and (98.8 ± 4.6)%, (98.9 ± 0.4)%, (94.4 ± 0.7)% respectively (all P < 0.05).

CONCLUSIONS

The ESCs in hypertrophic scar have the same characteristics with ESCs in normal skin. However, the ESCs from hypertrophic scar are lower than that from normal skin.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

[Research progress on keratinocyte growth factor]

OBJECTIVE

To review the latest research progress on keratinocyte growth factor (KGF), to thoroughly understand its basic characteristics and application methods and to lay a solid foundation for the research and development of new KGF medicines and improving the quality of skin substitutes.

METHODS

Domestica and international literatures on KGF in recent years were extensively reviewed and analyzed.

RESULTS

KGF was secreted by mesenchymal cells and its receptors were distributed in epithelium to promote the proliferation, migration and differentiation of epithelial cell specifically, which closely related to the organ development, wound healing, tumorigenesis and immune reconstruction.

CONCLUSION

KGF can be used to improve wound healing and the performance of skin substitutes. However, the structure of KGF needs to be changed to eliminate its side effects and purify its promoting effect on epithelial cell growth.

[Screening human keratinocyte growth factor mimic peptide with Ph.D.-7 phage display peptide library]

OBJECTIVE

To harvest human keratinocyte growth factor (KGF) mimic peptides with Ph.D.-7 phage display peptide library.

METHODS

Ph.D.-7 phage display peptide library was biopanned for 4 rounds to harvest monoclonal anti-body human KGF and then phage titer was detected. ELISA detection was performed to detect the binding force of random-selected monoclonal phages, thereafter DNA extracted from phages with better binding activity was sequenced and the Basic BLAST system was applied to conduct the sequence similarity and homology analysis.

RESULTS

After 4 rounds of biopanning, the titer of phages was increased gradually and the enrichment of specific phage mimic peptides was obtained. The titers of monoclonal phages were up to 2.0 x 10(4) pfu/mL according to ELISA detection. According to the absorbance value, the monoclonal phages with better binding activities to certain specific antibodies were sequenced, and 26 base sequences related to the promotion of division and growth were verified, 2 of which were similar to human KGF. Homology sequence analysis revealed that the common sequence of those 26 base sequences was similar to the partial sequences of human KGF.

CONCLUSION

The phage mimic peptides resembling or related to human KGF DNA can be harvested from Ph.D.-7 phage display peptide library, which may be conducive to improve human KGF performance, wound healing and the quality of tissue engineered skin substitutes.

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.

Measurement of direct photon production in p+p collisions at sqrt[s] = 200 GeV

Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < pT < 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for pT >5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT >7 GeV/c.

Azimuthal angle correlations for rapidity separated Hadron pairs in d+Au collisions at square root of sNN=200 GeV

Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at square root of sNN=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x~0.1 to ~0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions.

J/psi production and nuclear effects for d + Au and p + p collisions at square root of S(NN) = 200 GeV

J/psi production in d + Au and p + p collisions at square root of S(NN) = 200 GeV has been measured by the PHENIX experiment at rapidities -2.2 < y < +2.4. The cross sections and nuclear dependence of J/psi production versus rapidity, transverse momentum, and centrality are obtained and compared to lower energy p + A results and to theoretical models. The observed nuclear dependence in d + Au collisions is found to be modest, suggesting that the absorption in the final state is weak and the shadowing of the gluon distributions is small and consistent with Dokshitzer-Gribov-Lipatov-Altarelli-Parisi-based parametrizations that fit deep-inelastic scattering and Drell-Yan data at lower energies.

Dynamics of magnetic defects in heavy fermion LiV2O4 from stretched exponential 7Li NMR relaxation

7Li NMR measurements on LiV2O4 from 0.5 to 4.2 K are reported. A small concentration of magnetic defects within the structure drastically changes the nuclear magnetization relaxation versus time from a pure exponential as in pure LiV2O4 to a stretched exponential, indicating glassy behavior of the magnetic defects. The stretched exponential function is described as arising from a distribution of 7Li nuclear spin-lattice relaxation rates and we present a model for the distribution in terms of the dynamics of the magnetic defects. Our results explain the origin of recent puzzling 7Li NMR literature data on LiV2O4 and our model is likely applicable to other glassy systems.

Nuclear modification factors for hadrons at forward and backward rapidities in deuteron-gold collisions at sqrt[s(NN)]=200 GeV

We report on charged hadron production in deuteron-gold reactions at sqrt[s(NN)]=200 GeV. Our measurements in the deuteron direction cover 1.4<eta<2.2, referred to as forward rapidity, and in the gold direction -2.0<eta<-1.4, referred to as backward rapidity, and a transverse momentum range p(T)=0.5-4.0 GeV/c. We compare the relative yields for different deuteron-gold collision centrality classes. We observe a suppression relative to binary collision scaling at forward rapidity, sensitive to low momentum fraction (x) partons in the gold nucleus, and an enhancement at backward rapidity, sensitive to high momentum fraction partons in the gold nucleus.

Double helicity asymmetry in inclusive midrapidity pi0 production for polarized p+p collisions at square root s = 200 GeV

We present a measurement of the double longitudinal spin asymmetry in inclusive pi(0) production in polarized proton-proton collisions at sqrt[s]=200 GeV. The data were taken at the Relativistic Heavy Ion Collider with average beam polarizations of 0.27. The measurements are the first in a program to study the longitudinal spin structure of the proton, using strongly interacting probes, at collider energies. The asymmetry is presented for transverse momenta 1-5 GeV/c at midrapidity, where next-to-leading-order perturbative quantum chromodynamic (NLO pQCD) calculations well describe the unpolarized cross section. The observed asymmetry is small and is compared to a NLO pQCD calculation with a range of polarized gluon distributions.

Absence of suppression in particle production at large transverse momentum in sqrt[s(NN)]=200 GeV d+Au collisions

Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions with p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in d+Au collisions at sqrt[s(NN)]=200 GeV. The measured yields are compared to those in p+p collisions at the same sqrt[s(NN)] scaled up by the number of underlying nucleon-nucleon collisions in d+Au. The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC. Instead, there is a small enhancement in the yield of high momentum particles.

Design of a logarithmic k-space spiral trajectory

Spiral acquisitions are used in fast cardiac imaging because they traverse k-space efficiently and minimize flow artifacts. A variable pitch logarithmic spiral trajectory is designed to critically sample the low-frequency region in k-space and gradually undersample the high-frequency region. An approximate analytical expression for the trajectory provides a fast means to calculate the gradient waveforms and the sampled data points. A numerical method is introduced based on the trajectory curvature and the rate of change in the gradient magnitude with time for the composite Archimedean-logarithmic trajectory. The pulse sequence is implemented and images are acquired on phantoms and human hearts. The images show improved image resolution and some improvement in image quality as a result of increased extent in k-space and reduction in aliasing artifacts, respectively.

A single histidine residue determines the pH sensitivity of the pacemaker channel HCN2

Hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels control the rhythmic activity of heart and neuronal networks. The activation of these channels is regulated in a complex manner by hormones and neurotransmitters. In addition it was suggested that the channels may be controlled by the pH of the cytosol. Here we demonstrate that HCN2, a member of the HCN channel family, is directly modulated by the intracellular pH in the physiological range. Protons inhibit HCN2 channels by shifting the voltage dependence of channel activation to more negative voltages. By using site-directed mutagenesis, we have identified a single histidine residue (His-321) localized at the boundary between the voltage-sensing S4 helix and the cytoplasmic S4-S5 linker of the channel that is a major determinant of pH sensitivity. Replacement of His-321 by either arginine, glutamine, or glutamate results in channels that are no longer sensitive to shifts in intracellular pH. In contrast, cAMP-mediated modulation is completely intact in mutant channels indicating that His-321 is not involved in the molecular mechanism that controls modulation of HCN channel activity by cyclic nucleotides. Because His-321 is conserved in all four HCN channels known so far, regulation by intracellular pH is likely to constitute a general feature of both cardiac and neuronal pacemaker channels.

Cellular expression and functional characterization of four hyperpolarization-activated pacemaker channels in cardiac and neuronal tissues

Hyperpolarization-activated cation currents (I(h)) have been identified in cardiac pacemaker cells and a variety of central and peripheral neurons. Four members of a gene family encoding hyperpolarization-activated, cyclic nucleotide-gated cation channels (HCN1--4) have been cloned recently. Native I(h) currents recorded from different cell types exhibit distinct activation kinetics. To determine if this diversity of I(h) currents may be caused by differential expression of HCN channel isoforms, we investigated the cellular distribution of the transcripts of HCN1--4 in the murine sinoatrial node, retina and dorsal root ganglion (DRG) by in situ hybridization. In the sinoatrial node, the most prominently expressed HCN channel is HCN4, whereas HCN2 and HCN1 are detected there at moderate and low levels, respectively. Retinal photoreceptors express high levels of HCN1, whereas HCN2, 3 and 4 were not found in these cells. In DRG neurons, the dominant HCN transcript is HCN1, followed by HCN2. We next determined the functional properties of recombinant HCN1--4 channels expressed in HEK293 cells. All four channel types gave rise to I(h) currents but displayed marked differences in their activation kinetics. Our results suggest that the heterogeneity of native I(h) currents is generated, at least in part, by the tissue-specific expression of HCN channel genes.