Gut microbiome biomarkers in adolescent obesity: a regional study

Purpose

This study aimed to characterize the gut microbiota in obese adolescents from Shenzhen (China), and evaluate influence of gender on BMI-related differences in the gut microbiome.

Methods

Evaluation of physical examination, blood pressure measurement, serological assay and body composition were conducted in 205 adolescent subjects at Shenzhen. Fecal microbiome composition was profiled via high-throughput sequencing of the V3-V4 regions of the 16S rRNA gene. A Random Forest (RF) classifier model was built to distinguish the BMI categories based on the gut bacterial composition.

Results

Fifty-six taxa consisting mainly of Firmicutes were identified that having significant associations with BMI; 2 OTUs belonging to Ruminococcaceae and 1 belonging to Lachnospiraceae had relatively strong positive correlations with body fate rate, waistline and most of serum biochemical properties. Based on the 56 BMI-associated OTUs, the RF model showed a robust classification accuracy (AUC 0.96) for predicting the obese phenotype. Gender-specific differences in the gut microbiome composition was obtained, and a lower relative abundance of Odoribacter genus was particularly found in obese boys. Functional analysis revealed a deficiency in bacterial gene contents related to peroxisome and PPAR signaling pathway in the obese subjects for both genders.

Conclusions

This study reveals unique features of gut microbiome in terms of microbial composition and metabolic functions in obese adolescents, and provides a baseline for reference and comparison studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13755-023-00236-9.

Initial Experience with the Commercial Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The purpose of this study was to introduce a new commercial electron FLASH system that has the potential to become widely available for FLASH researchers globally. In this study, we first present the initial acceptance and commissioning tests for the FLASH system, and second, we highlight preliminary FLASH effect results from our cell studies.

MATERIALS/METHODS

A linear accelerator was converted into a commercial research platform with the FLASH Research Extension, enabling the generation of a powerful 16 MeV electron FLASH beam. The dosimetric and stability tests were conducted using various dosimeters (i.e., radiochromic film, optically stimulated luminescent dosimeters (OSLDs), and a plane-parallel ionization chamber). To evaluate the FLASH effect, normal and cancer cell lines were FLASH irradiated using different pulse repetition frequencies (PRF) of 18 pulses/s and 180 pulses/s.

RESULTS

The electron FLASH mode was able to generate over 1 Gy per pulse at the isocenter and a dose rate of up to 690 Gy/s near the accessory mount of the Linac gantry head. The charge collected by the plane-parallel ionization chamber at the highest PRF (i.e., 180 pulses/s) showed a linear relationship with the delivered number of pulses (i.e., 1 to 99 pulses) with a coefficient of determination (R2) of 0.9996. The absorbed dose measured using radiochromic film and OSLDs agreed within 3%, on average, and followed an inverse square law as the source-to-axis distance (SAD) varied for which the R2 values were 0.9972 and 0.9955 for radiochromic film and OSLDs, respectively. The profile of the FLASH beam was symmetrical but was not as flat as the conventional 16 MeV electron beam due to the use of a thinner custom scattering foil to reduce the degradation of the ultra-high dose rate. The depth-dose curve beyond the build-up region for the FLASH beam was similar to the conventional 16 MeV electron beam for which the range at 50% the maximum dose (R50) agreed within 0.5 mm. The FLASH beam output remained consistent over a 4-month period with a variation of 2.5%, on average. The FLASH sparing effect was observed in vitro for healthy human pancreatic cells. Furthermore, we observed that the highest PRF beam (180 pulses/s) was more effective at destroying pancreatic cancerous cells while minimizing damage to healthy cells compared to the lowest PRF beam (18 pulses/s).

CONCLUSION

The novel commercial FLASH Research Extension system was dosimetrically characterized for pre-clinical FLASH research, and preliminary in vitro results demonstrated the FLASH effect. Given the prevalence of linear accelerators, this new commercial system has the potential to greatly increase the access to FLASH research.

Commissioning and Initial Validation of Commercial Treatment Planning System for the Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The aim of this study was to investigate the feasibility of commissioning the 16 MeV electron FLASH beam in a commercial treatment planning system (TPS) for pre-clinical research purposes. The delivery system consisted of a new commercial solution for which a linear accelerator was modified into a FLASH Research Extension platform. Additionally, preliminary radiation biology results were highlighted to showcase the future use of this system.

MATERIALS/METHODS

To commission a commercial electron Monte Carlo (MC) for dose calculation of a 16 MeV FLASH beam in the TPS, radiochromic film was used to measure the vendor-required beam data, e.g., profiles and percent depth dose (PDD) curves for cone sizes of 6 × 6 cm2, 10 × 10 cm2, and 15 × 15 cm2 as well as an in-air profile for a 40 × 40 cm2 open field (no cone). Once the electron MC beam model was generated, additional measurements were collected for validation and compared against the calculated dose from the TPS. A treatment planning comparison between the newly commissioned FLASH beam and the conventional electron beam was conducted. Specifically, the dose-volume histograms (DVHs) for target volumes and organs at risk were investigated for skin cancer cases previously treated with conventional electron beams. Lastly, the FLASH dose distribution predicted by the electron MC for an in vitro cell study setup was validated with radiochromic film measurements, and initial radiobiology tests were conducted using FLASH and conventional dose-rate electron beams.

RESULTS

The electron MC calculated dose for the 16 MeV electron FLASH beam agreed with measured PDDs within 1% for all field sizes. The beam profile characteristics, such as penumbra, shape, and full width at half maximum, demonstrated good agreement with less than 0.5 mm difference between the TPS and measurements. There were noticeable differences in the profiles of large fields between the FLASH and conventional dose-rate beam models due to the more forward-peaked FLASH beam. For treatment planning, Regarding DVH, the FLASH dose-rate plan provided comparable plan quality to the conventional dose-rate plan, achieving adequate coverage for the target volumes and sparing the healthy organs and tissues. The electron MC dose prediction for the FLASH beam was also found to be in good agreement with the film measurements of the in vitro cell study setup. Furthermore, the FLASH beam was observed to be more effective with a 20 % increase in killing pancreatic cancer cells compared to the conventional dose rate.

CONCLUSION

The study successfully incorporated the 16 MeV electron FLASH Research Extension into the commercial TPS using electron Monte Carlo for dose calculation. This will be valuable for pre-clinical cell and animal studies. This research also enables FLASH treatment planning studies, a key component for the future implementation of FLASH into clinical care. Further research is necessary to incorporate the radiation biology effect of FLASH into the treatment planning system.

Fourfold Anisotropic Magnetoresistance of L1_{0} FePt Due to Relaxation Time Anisotropy

Experimental measurements show that the angular dependence of the anisotropic magnetoresistance (AMR) in L1_{0} ordered FePt epitaxial films on the current orientation and magnetization direction is a superposition of the corresponding dependences of twofold and fourfold symmetries. The twofold AMR exhibits a strong dependence on the current orientation, whereas the fourfold term only depends on the magnetization direction in the crystal and is independent of the current orientation. First-principles calculations reveal that the fourfold AMR arises from the relaxation time anisotropy due to the variation of the density of states near the Fermi energy under rotation of the magnetization. This relaxation time anisotropy is a universal property in ferromagnetic metals and determines other anisotropic physical properties that are observable in experiment.

Study of Mental Health Status of the Resident Physicians in China During the COVID-19 Pandemic

Objective

Investigating the mental health status of Chinese resident physicians during the 2019 new coronavirus outbreak.

Methods

A cluster sampling method was adopted to collect all China-wide resident physicians during the epidemic period as the research subjects. The Symptom Checklist-90 self-rating scale was used to assess mental health using WeChat electronic questionnaires.

Results

In total, 511 electronic questionnaires were recovered, all of which were valid. The negative psychological detection rate was 93.9% (480/511). Among the symptoms on the self-rating scale, more than half of the Chinese resident physicians had mild to moderate symptoms of mental unhealthiness, and a few had asymptomatic or severe unhealthy mental states. In particular, the detection rate of abnormality was 88.3% (451/511), obsessive-compulsive symptoms was 90.4% (462/511), the sensitive interpersonal relationship was 90.6% (463/511), depression abnormality was 90.8% (464)/511), anxiety abnormality was 88.3% (451/511), hostility abnormality was 85.3% (436/511), terror abnormality was 84.9% (434/511), paranoia abnormality was 86.9% (444/511), psychotic abnormalities was 89.0% (455/511), and abnormal sleeping and eating status was 90.8% (464/511). The scores of various psychological symptoms of pediatric resident physicians were significantly lower than those of non-pediatrics (p < 0.05).

Conclusion

The new coronavirus epidemic has a greater impact on the mental health of Chinese resident physicians.

[An acute schistosomiasis case in Wuhan City imported from another province of China in 2020]

An imported case of acute schistosomiasis was reported in Wuhan City in 2020. The case was infected with Schistosoma by contact with the infested water due to playing water in the Yangtze River when working out of Hubei Province. The patient visited four medical institutions and the duration from onset to definitive diagnosis was 20 days. The patient's low awareness of schistosomiasis prevention and control knowledge and lack of diagnosis and treatment awareness for schistosomiasis among medical institutions were considered as main causes of the development of acute schistosomiasis and progression to severe case. Intensifying schistosomiasis health education among mobile populations and improving the awareness and capability of early diagnosis of schistosomiasis among clinicians are recommended.

Phylogenetic Comparison and Splicing Analysis of the U1 snRNP-specific Protein U1C in Eukaryotes

As a pivotal regulator of 5’ splice site recognition, U1 small nuclear ribonucleoprotein (U1 snRNP)-specific protein C (U1C) regulates pre-mRNA splicing by interacting with other components of the U1 snRNP complex. Previous studies have shown that U1 snRNP and its components are linked to a variety of diseases, including cancer. However, the phylogenetic relationships and expression profiles of U1C have not been studied systematically. To this end, we identified a total of 110 animal U1C genes and compared them to homologues from yeast and plants. Bioinformatics analysis shows that the structure and function of U1C proteins is relatively conserved and is found in multiple copies in a few members of the U1C gene family. Furthermore, the expression patterns reveal that U1Cs have potential roles in cancer progression and human development. In summary, our study presents a comprehensive overview of the animal U1C gene family, which can provide fundamental data and potential cues for further research in deciphering the molecular function of this splicing regulator.

Large ultrafast-modulated Voigt effect in noncollinear antiferromagnet Mn3Sn

The time-resolved magneto-optical (MO) Voigt effect can be utilized to study the Néel order dynamics in antiferromagnetic (AFM) materials, but it has been limited for collinear AFM spin configuration. Here, we have demonstrated that in Mn₃Sn with an inverse triangular spin structure, the quench of AFM order by ultrafast laser pulses can result in a large Voigt effect modulation. The modulated Voigt angle is significantly larger than the polarization rotation due to the crystal-structure related linear dichroism effect and the modulated MO Kerr angle arising from the ferroic ordering of cluster magnetic octupole. The AFM order quench time shows negligible change with increasing temperature approaching the Néel temperature (T_N), in markedly contrast with the pronounced slowing-down demagnetization typically observed in conventional magnetic materials. This atypical behavior can be explained by the influence of weakened Dzyaloshinskii–Moriya interaction rather than the smaller exchange splitting on the diminished AFM order near T_N. The temperature-insensitive ultrafast spin manipulation can pave the way for high-speed spintronic devices either working at a wide range of temperature or demanding spin switching near T_N.

Mn3Sn is an anti-ferromagnetic material which displays a large magneto-optical Kerr effect, despite lacking a ferromagnetic moment. Here, the authors show that likewise, Mn3Sn, also presents a particularly large magneto-optical Voigt signal, with a negligible change in the quench time over a wide temperature range.

Phylogenetic comparison and splice site conservation of eukaryotic U1 snRNP-specific U1-70K gene family

Eukaryotic cells can expand their coding ability by using their splicing machinery, spliceosome, to process precursor mRNA (pre-mRNA) into mature messenger RNA. The mega-macromolecular spliceosome contains multiple subcomplexes, referred to as small nuclear ribonucleoproteins (snRNPs). Among these, U1 snRNP and its central component, U1-70K, are crucial for splice site recognition during early spliceosome assembly. The human U1-70K has been linked to several types of human autoimmune and neurodegenerative diseases. However, its phylogenetic relationship has been seldom reported. To this end, we carried out a systemic analysis of 95 animal U1-70K genes and compare these proteins to their yeast and plant counterparts. Analysis of their gene and protein structures, expression patterns and splicing conservation suggest that animal U1-70Ks are conserved in their molecular function, and may play essential role in cancers and juvenile development. In particular, animal U1-70Ks display unique characteristics of single copy number and a splicing isoform with truncated C-terminal, suggesting the specific role of these U1-70Ks in animal kingdom. In summary, our results provide phylogenetic overview of U1-70K gene family in vertebrates. In silico analyses conducted in this work will act as a reference for future functional studies of this crucial U1 splicing factor in animal kingdom.

Prevention program for the COVID-19 in a children’s digestive endoscopy center

The pneumonia caused by the coronavirus disease-2019 (COVID-19) outbreak in Wuhan, China constitutes a public health emergency of international concern. The gastrointestinal symptoms of vomiting, diarrhea and abdominal pain and the detection of COVID-19 nucleic acid from fecal specimens in a small number of patients suggest the possibility of transmission via the gastrointestinal tract. People of all ages are vulnerable to this virus, including children. Digestive endoscopy is an invasive procedure during which children cannot wear masks; therefore, they have higher risks of exposure to COVID-19, and the digestive endoscopy center is a relatively high-risk area for COVID-19 infection. Based on these factors and in combination with related policies and regulations, a prevention and control program for the COVID-19 pneumonia in a children's digestive endoscopy center was established to prevent the COVID-19 nosocomial infection.

Knockdown of Long Noncoding RNAs of Maternally Expressed 3 Alleviates Hyperoxia-Induced Lung Injury via Inhibiting Thioredoxin-Interacting Protein-Mediated Pyroptosis by Binding to miR-18a

Long-term hyperoxia exposure may cause lung damage with characteristic inflammation. Long noncoding RNA of maternally expressed 3 (MEG3) is up-regulated in lung tissues exposed to hyperoxia; however, the underlying mechanism is unclear. Hyperoxia-induced cells and mouse models were used to study these mechanisms. Molecular assays were used to detect cell viability, cytotoxicity, and expression of miR-18a, MEG3, and inflammatory cytokines. The interaction among MEG3, miR-18a, and thioredoxin-interacting protein (TXNIP) was verified; and pyroptosis-related proteins were analyzed. The in vivo model was established by exposing MEG3 knockdown mice to hyperoxia. Hematoxylin and eosin staining was used to assess pathologic alterations of lung tissues. Hyperoxia suppressed cell viability, induced cell damage, and exacerbated the secretion of IL-1β and IL-18. Hyperoxia inhibited miR-18a, with increased expression of MEG3, TXNIP, and nonobese diabetic-like receptor family pyrin domain containing 3 (NLRP3). MEG3 aggravated TXNIP expression by binding to miR-18a. Knockdown of MEG3 rescued hyperoxia-induced pyroptosis by up-regulating miR-18a. Furthermore, knockdown of MEG3 inhibited NLRP3 inflammasome activity and caspase-1 signaling by miR-18a. In vivo knockdown of MEG3 and overexpression of miR-18a relieved hyperoxia-induced lung injury via restraining NLRP3 inflammasome-mediated pyroptosis, whereas miR-18a inhibition reversed these effects. In conclusion, knockdown of MEG3 inhibits pyroptosis to alleviate hyperoxia lung injury by suppressing NLRP3 inflammasome and caspase-1 signaling via regulating miR-18a-TXNIP axis.

[Risk factors for cow's milk protein allergy in infants: a multicenter survey]

OBJECTIVE

To investigate the risk factors for cow's milk protein allergy (CMPA) among infants through a multicenter clinical study.

METHODS

A total of 1 829 infants, aged 1-12 months, who attended the outpatient service of the pediatric department in six hospitals in Shenzhen, China from June 2016 to May 2017 were enrolled as subjects. A questionnaire survey was performed to screen out suspected cases of CMPA. Food avoidance and oral food challenge tests were used to make a confirmed diagnosis of CMPA CMPA. A multivariate logistic regression analysis was used to investigate the risk factors for CMPA.

RESULTS

Among the 1 829 infants, 82 (4.48%) were diagnosed with CMPA. The multivariate logistic regression analysis showed that maternal food allergy (OR=4.91, 95%CI: 2.24-10.76, P<0.05), antibiotic exposure during pregnancy (OR=3.18, 95%CI: 1.32-7.65, P<0.05), and the introduction of complementary food at an age of <4 months (OR=3.55, 95%CI: 1.52-8.27, P<0.05) were risk factors for CMPA, while exclusive breastfeeding (OR=0.21, 95%CI: 0.08-0.58, P<0.05) and the introduction of complementary food at an age of >6 months (OR=0.38, 95%CI: 0.17-0.86, P<0.05) were protective factors.

CONCLUSIONS

The introduction of complementary food at an age of <4 months, maternal food allergy, and antibiotic exposure during pregnancy are risk factors for CMPA in infants.

Chemical Modulation of Alternative Splicing for Molecular-Target Identification by Potential Genetic Control in Agrochemical Research

Alternative splicing (AS), the process of removing introns from pre-mRNA and the rearrangement of exons to produce several types of mature transcripts, is a remarkable step preceding protein synthesis. In particular, it has now been conclusively shown that up to ∼95% of genes are alternatively spliced to generate a complex and diverse proteome in eukaryotic organisms. Consequently, AS is one of the determinants of the functional repertoire of cells. Many studies have revealed that AS in plants can be regulated by cell type, developmental stage, environmental stress, and the circadian clock. Moreover, increasing amounts of evidence reveal that chemical compounds can affect various steps during splicing to induce major effects on plant physiology. Hence, the chemical modulation of AS can serve as a good strategy for molecular-target identification in attempts to potentially control plant genetics. However, the kind of mechanisms involved in the chemical modulation of AS that can be used in agrochemical research remain largely unknown. This review introduces recent studies describing the specific roles AS plays in plant adaptation to environmental stressors and in the regulation of development. We also discuss recent advances in small molecules that induce alterations of AS and the possibility of using this strategy in agrochemical-target identification, giving a new direction for potential genetic control in agrochemical research.

Accuracy of multi-echo Dixon sequence in quantification of hepatic steatosis in Chinese children and adolescents

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is currently the outstanding cause of chronic liver disease in children and adolescents, especially in overweight and obese groups. Liver biopsy is the reference standard to diagnose NAFLD but invasive, thus it is not the best choice in clinical diagnosis and follow-up. Magnetic resonance (MR) is widely used in clinical trials to noninvasively quantify liver fat content in adults and children in foreign countries. While currently, it is rarely used in Chinese children and adolescents. We postulated that quantifying hepatic steatosis by MR could be extended to children and adolescents in China.

AIM

To investigate the accuracy of MR imaging (MRI) in quantifying liver fat with MR spectroscopy (MRS) as a reference. A secondary goal was to assess the prevalence of NAFLD in overweight and obese Chinese children and adolescents.

METHODS

There were 86 children and adolescents enrolled in this study, including 65 overweight and obese children and 21 healthy children. The participants underwent MRI and MRS. MRI and MRS were performed using multi-echo Dixon and HISTO sequences, respectively, to calculate hepatic proton density fat fraction (PDFF). Hepatic steatosis was diagnosed using MRS-PDFF > 5% as the threshold. Spearman’s analysis was used to evaluate the correlation between MRI and MRS. The agreement between these two methods was assessed by Bland-Altman analysis.

RESULTS

The MRI-PDFF in the MRS region of interest and the entire liver was 9.9% ± 10.3% with a range of 0.3%-39.9%, and 10.6% ± 9.4% with a range of 1.9%-38.9%, respectively. The MRS-PDFF was 9.1% ± 10.0%, with a range of 0.5%-37.8%. The incidence of hepatic steatosis detected by MRS-PDFF was 46.5% (40/86) of all participants, all of whom belonged to the overweight and obese group. Spearman’s analysis indicated an excellent correlation between multi-echo Dixon and MRS (r > 0.9, P < 0.01). Bland-Altman analysis also demonstrated a good agreement between these two methods.

CONCLUSION

Multi-echo Dixon shows an excellent correlation and agreement with MRS in quantifying liver fat content and could be a potential tool to detect hepatic steatosis in Chinese children and adolescents.

Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature

Steroid 5β-reductase [aldo-keto reductase family 1 member D1 (AKR1D1)] is essential for bile acid biosynthesis. Bile acid deficiency caused by genetic defects in AKR1D1 leads to life-threatening neonatal hepatitis and cholestasis. There is still limited experience regarding the treatment of this disease. We describe an infant who presented with hyperbilirubinemia and coagulopathy but normal bile acid and γ-glutamyltransferase. Gene analysis was performed using genomic DNA from peripheral lymphocytes from the patient, his parents, and his elder brother. The patient was compound heterozygous for c.919C>T in exon 8 and exhibited a loss of heterozygosity of the AKR1D1 gene, which led to an amino acid substitution of arginine by cysteine at amino acid position 307 (p.R307C). Based on these mutations, the patient was confirmed to have primary 5β-reductase deficiency. Ursodeoxycholic acid (UDCA) treatment did not have any effect on the patient. However, when we changed to chenodeoxycholic acid (CDCA) treatment, his symptoms and laboratory tests gradually improved. It is therefore crucial to supplement with an adequate dose of CDCA early to improve clinical symptoms and to normalize laboratory tests.

[Dynamic investigation of nutritional risk in patients with malignant tumor during hospitalization]

Objective: To prospectively investigate the changes in nutritional status of patients with malignant tumors during hospitalization by using nutritional risk screening (NRS2002), and to analyze the correlation between the nutritional status and clinical outcomes . Methods: This was a prospective and parallel research done by multi-center collaboration from 34 hospitals in China from June to September 2014.Hospitalized patients with malignant tumors inthese departments (Department of Gastroenterology, respiratory medicine, oncology, general surgery, thoracic surgery and geriatrics)were investigated. Only the patients with age≥ 18 years and hospitalization time between 7-30 days were included. During hospitalization, the physical indexes of human bodywere measured, and the NRS 2002 scores, and monitored the nutritional support at the time points of admission and 24 hours before discharge were recorded.And whether there was a nutritional risk in hospitalized patients and its association with clinical outcomes were investigated. Results: A total of 2 402 patients with malignancies were enrolled in this study. Seventy fourpatients who did not complete NRS2002 were eliminated, and 2 328 patients were included. The number of the main diseases was the top five, including 587 cases of colorectal cancer, 567 cases of lung cancer, 564 cases of gastric cancer, 146 cases of esophageal cancer, and 119 cases of liver tumor. At the time of discharge, compared with admission, the BMI, body weight, grip and calf circumferences of patients with malignant tumor were significantly decreased (P<0.05). The total protein, albumin, prealbumin and hemoglobin were significantly lower than those at admission (P<0.05). In 2 328 patients who were completed nutritional risk screening, the rate of malnutrition at admission was 11.1% (BMI =18.5, 258/2 328) and the rate of malnutrition at discharge was 10.9% (BMI =18.5, 254/2 328), there were no significant differences (χ(2)=0.019 7, P=0.888). There were 1 204 patients with nutritional risk at admission (51.7%, NRS2002 score≥3)and 1 352 patients with nutritional risk at discharge (58.1%, NRS2002 score≥3), with significant differences (χ(2)=49.9, P<0.001). The incidence of nutritional risk in patients with colorectal, stomach, and lung tumors at discharge was significantly higher than that at admission (P<0.05). The infective complications and other complications of patients with nutritional risk were significantly greater than those without nutritional risk at admission and at discharge.ICU hospitalization stay of patients with nutritional risk was increased significantly than those without nutritional risk at admission(P=0.042). Hospitalization expenses of patients with nutritional risk was increased significantly than those of patients without nutritional risk at discharge(P<0.01). Conclusion: The patients with malignant tumor have a higher incidence rate of malnutrition at both admission and discharge and malnutritionhas correlation with adverse clinical outcomes.The aboveindicators did not improve significantly at discharge.Doctors should pay more attention to the nutritional status (screening and evaluation)of patients before discharge and use appropriate and adequate nutrition support in order to prevent the weight loss and improve the life quality of patients.

Relationship between gut microbiota and gastrointestinal disorders in patients with autism spectrum disorders

Autism spectrum disorders (ASDs) are a group of neurodevelopmetal disorders with increasing morbidity. Gastrointestinal disorders such as diarrhea, constipation and abdominal pain are common among patients with ASDs. This article reviews studies on gastrointestinal disorders among ASD patients, with great importance attached to the role of gut microbiota in ASD pathogenesis. We propose that food rich in probiotics and/or prebiotics should be designed for ASD patients to help improve their gut micorbiota disorders.

Nexrutine inhibits cancer cell growth as a consequence of mitochondrial damage and mitophagy

BACKGROUND/AIMS

Nexrutine is an herbal extract of Phellodendron amurense and has been used as nutrient supplement in China as well as America. Potential protection effect of Nexrutine has been reported.

METHODS

To investigate the mechanism of Nexrutine, we used the HeLa, U2OS and HCT116 as a model. Based on the acidification of cell culture media, we examined the lactate, mitochondria damage as well as mitophagy status by corresponding assay.

RESULTS

Our data suggest that Nexrutine alters the cellular glucose metabolism to promote lactate production. This effect is caused by mitochondrial damage, not an alteration to lactate dehydrogenase activity. As a result of the mitochondrial damage, cell proliferation was inhibited and was associated with an elevation in p21/p27 proteins, which are both important cell cycle inhibitors. As another consequence of the mitochondrial damage, mitophagy was highly activated in Nexrutine-treated cells in a dose-dependent manner. When the autophagy pathway was blocked by siRNAs against BECN1 or ATG7, the growth inhibition caused by Nexrutine was reversed.

CONCLUSION

Our study revealed that autophagy plays an important role in the inhibition of cancer cell proliferation by Nexrutine.

Mapping motion of antiferromagnetic interfacial uncompensated magnetic moment in exchange-biased bilayers

In this work, disordered-IrMn3/insulating-Y3Fe5O12 exchange-biased bilayers are studied. The behavior of the net magnetic moment ΔmAFM in the antiferromagnet is directly probed by anomalous and planar Hall effects, and anisotropic magnetoresistance. The ΔmAFM is proved to come from the interfacial uncompensated magnetic moment. We demonstrate that the exchange bias and rotational hysteresis loss are induced by partial rotation and irreversible switching of the ΔmAFM. In the athermal training effect, the state of the ΔmAFM cannot be recovered after one cycle of hysteresis loop. This work highlights the fundamental role of the ΔmAFM in the exchange bias and facilitates the manipulation of antiferromagnetic spintronic devices.

[Prognostic analysis of children with Henoch-Schonlein purpura treated by Helicobacter pylori eradication therapy]

OBJECTIVE

To investigate the effect of Helicobacter pylori (Hp) eradication therapy on prognosis in children with Henoch-Schonlein purpura (HSP).

METHODS

A total of 153 children with HSP were divided into Hp infection treatment group (n=22), Hp infection control group (n=21), and Hp infection-negative group (n=110). The Hp infection treatment group received one-week triple therapy for Hp eradication in addition to conventional treatment, while the Hp infection control group and Hp infection-negative group received conventional treatment. All patients were followed up for prognostic evaluation.

RESULTS

The response rates of the Hp infection treatment, control, and negative groups were 86% (19/22), 90% (19/21) and 85% (94/110), respectively (P>0.05). The recurrence rates of HSP in the Hp infection treatment, control, and negative groups were 14% (3/22), 24% (5/21) and 31% (34/110), respectively (P>0.05). The incidence of Henoch-Schonlein purpura nephritis (HSPN) in the Hp infection-negative group (36%, 40/110) and control group (33%, 7/21) was significantly higher than that in the Hp infection treatment group (5%, 1/22) (P<0.05 for both), but no significant difference in the incidence of HSPN was found between the control and negative groups (P>0.05).

CONCLUSIONS

One-week triple therapy for Hp eradication may be useful to reduce the incidence of HSPN in children with HSP infected with Hp.

Visceral granulomas in farmed large yellow croaker, Larimichthys crocea (Richardson), caused by a bacterial pathogen, Pseudomonas plecoglossicida

An enzootic disease characterized by granulomas in internal organs occurred in cage-farmed large yellow croaker, Larimichthys crocea (Richardson), in April and November 2010, in Ningbo, Zhejiang Province. One bacterial strain, named XSDHY-P, was isolated from the diseased fish and identified by biochemical characterization, fatty acid methyl ester (FAME) analysis and multilocus sequence analysis (MLSA). According to the results obtained from the biochemical tests, FAME analysis and phylogenetic analysis derived from 16S ribosomal RNA, gyrB, oprF, oprI, oprL and rpoD gene sequencing, the bacterial isolate, XSDHY-P, was identified as Pseudomonas plecoglossicida. Moreover, lethal dose, 50% trials were carried out to demonstrate the virulence of XSDHY-P in large yellow croaker when administered at 2.13 9 105 colony-forming units per fish. Visceral granulomas were found in the experimentally infected fish as well as in the naturally infected fish, indicating that P. plecoglossicida is another bacterial pathogen that causes granulomatosis in L. crocea.

Quadratic scaling of intrinsic Gilbert damping with spin-orbital coupling in L10 FePdPt films: experiments and Ab initio calculations

The dependence of the intrinsic Gilbert damping parameter α(0) on the spin-orbital coupling strength ξ is investigated in L1(0) ordered FePd(1-x) Pt(x) films by time-resolved magneto-optical Kerr effect measurements and spin-dependent ab initio calculations. Continuous tuning of α(0) over more than one order of magnitude is realized by changing the Pt/Pd concentration ratio showing that α(0) is proportional to ξ(2) as changes of other leading parameters are found to be negligible. The perpendicular magnetic anisotropy is shown to have a similar variation trend with x. The present results may facilitate the design and fabrication of new magnetic alloys with large perpendicular magnetic anisotropy and tailored damping properties.

Chemical composition tuning of the anomalous Hall effect in isoelectronic L10FePd(1-x)Pt(x) alloy films

The anomalous Hall effect (AHE) in L1(0)FePd(1-x)Pt(x) alloy films is studied both experimentally and theoretically. We find that the intrinsic contribution (σ(AH)(int)) to the AHE can be significantly increased, whereas the extrinsic side-jump contribution (σ(AH)(sj)) can be continuously reduced from being slightly larger than σ(AH)(int) in L1(0) FePd to being much smaller than σ(AH)(int) in L1(0) FePt, by increasing the Pt composition x. We show that this chemical composition tuning of the intrinsic contribution is afforded by the stronger spin-orbit coupling strength on the Pd/Pt site when the lighter Pd atoms are replaced by the heavier Pt atoms. Our results provide a means of manipulating the competing AHE mechanisms in ferromagnetic alloys for fully understanding the AHE and also for technological applications of ferromagnetic alloys.

Rapid identification of Streptococcus iniae by specific PCR assay utilizing genetic markers in ITS rDNA

The 16S-23S intergenic spacers (ITS) of ribosomal DNA from ten independent isolates of Streptococcus iniae and one reference strain ATCC29178 were sequenced, aligned and used to design a polymerase chain reaction (PCR) primer set for rapid and specific detection and identification of S. iniae. This primer set amplified a 377-bp DNA fragment specifically from S. iniae, but not from other common bacterial pathogens of fish or from non-fish pathogens. The PCR conditions were optimized to allow detection of the organism from agar, broth culture or infected fish tissue. The sensitivity of the PCR assay was established by the detection of DNA as low as 0.02 ng or as few as 10 CFU bacterial cells. The establishment of the specific PCR assay provides a useful tool for the identification and diagnosis of fish infection with S. iniae.

Femtosecond laser-drilling-induced HgCdTe photodiodes

Femtosecond-laser drilling may induce holes in HgCdTe with morphology similar to that induced by ion-milling in loophole technique. So-formed hole structures are proven to be pn junction diodes by the laser beam induced current characterization as well as the conductivity measurement. Transmission and photoluminescence spectral measurements on a n-type dominated hole-array structure give rise to different results from those of an ion-milled sample.

Electron spin resonance study of polycrystalline La(0.75)(Ca(x)Sr(1-x))(0.25)MnO(3) (x = 0, 0.45, 1)

Electron spin resonance (ESR) spectra of polycrystalline La(0.75)(Ca(x)Sr(1-x))(0.25)MnO(3) (x = 0, 0.45, 1) were studied within the temperature range 110 K≤T≤470 K. The temperature dependence of the ESR intensity for the samples is described by a thermally activated model in the paramagnetic regime. It is found that the activation energy in the orthorhombic phase is higher than that in the rhombohedral phase for La(0.75)(Ca(0.45)Sr(0.55))(0.25)MnO(3). It is suggested that a higher energy is required to destroy the correlated polarons due to the fact that correlated polarons only exist in the orthorhombic phase. This proposition is confirmed by the analysis of the ESR linewidth data, which can be well fitted by the model of adiabatic hopping motion of small polarons. In addition, it is found that, at a fixed temperature, the linewidth decreases with increasing Sr doping, which reveals that the structural tolerance factor has a significant effect on the linewidth.

Lymphocytic HLA-A mRNA is a reliable indicator of acute rejection in renal transplantation

BACKGROUND

Rejection in renal transplantation is the most frequent event causing transplant failure. It is important to identify parameters to predict rejection, which are helpful in a timely fashion.

METHODS

Fifty-nine renal transplant recipients were divided into two groups: group 1 (stable renal function) and group 2 (acute rejection episodes). The levels of HLA-A mRNA in peripheral blood lymphocytes (both pre- and posttransplantation) were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) with glucose-6-phosphate dehydrogenase (G6PDH) as an internal reference. The TEST software was used to analyze the relative expressions of HLA-A mRNA.

RESULTS

There was no statistical significance between features of the two groups pretransplant versus normal controls. Posttransplant, the HLA-A mRNA levels decreased significantly compared to those of pretransplant and normal control individuals. The levels of HLA-A mRNA among the 10 patients with acute rejection episodes were significantly increased. There was no significant change in the lymphocyte populations in the early stage of an acute rejection episode compared with the prerejection value.

CONCLUSION

HLA-A mRNA expression was strongly correlated with immune status. The HLA-A mRNA levels may provide an effective and reliable indicator to predict acute rejection episodes in renal transplantation.

Rotation of the pinning direction in the exchange bias training effect in polycrystalline NiFe/FeMn bilayers

For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively.

Systemic lupus erythematosus: a genetic epidemiology study of 695 patients from China

Our purpose was to explore potential genetic models for systemic lupus erythematosus (SLE) and analyze genetic epidemiologic characteristics of SLE in a Chinese population. Data for 695 patients with SLE were obtained by using a uniform questionnaire. Patients, clinical characteristics and their family history were analyzed using software. A complex segregation analysis was conducted to propose potential genetic models for SLE. The mean +/- SD age of onset were 30.2 +/- 10.5 years and mean time to progression to SLE was 32.5 +/- 44.4 months. The most frequent initial manifestations were malar rash (61.3%). During the evolution of the disease, the main clinical features were arthritis in 73.6% of our patients, followed by malar rash (68.1%), and renal involvement (56.7%). As the first symptom, the late-onset group (onset of disease beyond the age of 50 years) less often showed malar rash (45% vs. 63.4% in the early-onset group; p = 0.001). There were no significant differences in the other cumulative clinical symptoms between late-onset and early-onset group, except for a lower prevalence of malar rash, photosensitivity and alopecia and a higher prevalence of mucosal ulcers in the late-onset group. A positive family history of SLE was obtained in 50 patients (7.2%). There were no statistical differences in clinical characteristics between familial SLE and sporadic SLE patients. The heritability of SLE was 43.6%, the genetic model of SLE could be polygenetic model and major gene mode is the best fitted one. SLE could be a multifactorial disease with polygenetic model.

Hysteretic behavior of angular dependence of exchange bias in FeNi/FeMn bilayers

For FeNi/FeMn bilayers, the angular dependence of exchange bias shows hysteresis between clockwise and counterclockwise rotations, as a new signature. The hysteresis decreases for thick antiferromagnet layers. Calculations have clearly shown that the orientation of antiferromagnet spins also exhibits hysteresis between clockwise and counterclockwise rotations. This furnishes an interpretation of the macroscopic behavior of the ferromagnetic layer in terms of the thermally driven evolution of the magnetic state of the antiferromagnet layer.

[Roles of bile and gastrin in the pathogenesis of childhood gastroesophageal reflux disease]

OBJECTIVE

To explore the incidence of acid and bile reflux in children with gastroesophageal reflux disease (GERD) and to study the roles of bile and gastrin in the pathogenesis of childhood GERD.

METHODS

Forty-two cases of GERD were divided into two groups according to endoscopic findings: reflux esophagitis (RE) and non-erosive reflux disease (NERD). The patients underwent 24-hr ambulatory esophageal pH and bilirubin monitoring. The serum concentration of gastrin was detected by radioimmunoassay. Thirteen children without gastroesophageal reflux symptoms, digestive tract disease and severe systemic organic disease served as the Control group.

RESULTS

Of the 42 cases of GERD, 24 cases were confirmed with RE, with esophageal mucosal lesions, and 18 were NERD without esophageal mucosal lesions by endoscopy. Both acid and bile reflux parameters, including the percentage of total time with pH < 4 and bilirubin absorbance >/= 0.14, the total number of reflux episodes and the number of bile reflux episodes lasting longer than 5 minutes, were significantly higher in the GERD patients than those in the Control group (P < 0.05). The time of esophageal acid exposure (pH < 4) and the percentage of total time with bilirubin absorbance >/= 0.14 increased significantly in the RE group compared with in the NERD group (P < 0.05). Sixteen RE patients had a mixed reflux of bile and acid (66.7%) but only 6 NERD patients (33.3%) had (P < 0.01). The serum concentration of gastrin in the RE group (125.12 +/- 45.06 pg/mL) and the NERD group (98.22 +/- 27.92 pg/mL) was significantly higher than that of the Control group (74.22 +/- 20.34 pg/mL) (P < 0.01, P < 0.05 respectively). A significant difference was noted in the serum concentration of gastrin between the RE and the NERD groups (P < 0.05).

CONCLUSIONS

Mixed reflux of bile and acid are common in children with GERD. Bile reflux may play a role in the development of GERD. Gastrin parasecretion may participate in the development of GERD. Gastrin and bile reflux may have synergistic effects on the development of childhood GERD.

The impact of pre-radiotherapy surgery on radiation-induced lung injury

AIMS

The use of postoperative radiation therapy (PORT) is predicated by an assessment of the potential benefits and risks, including radiation-induced lung injury. In this study, the risk of radiation-induced lung injury is assessed in patients who received PORT, and compared with a group of patients who received radiation without prior surgery, to determine if surgery increases the risk of radiation pneumonitis.

MATERIALS AND METHODS

From 1991 to 2003, 251 patients with lung cancer were enrolled into a prospective study to assess radiation-induced lung injury. All patients received three-dimensional-planned, external-beam radiotherapy. One hundred and seventy-seven patients with over 6-months follow-up were eligible. For the current analysis, 49 patients (28%) had surgical intervention before radiotherapy. The rates of Grade 2 symptomatic pneumonitis in subgroups, based on the type of pre-radiation surgery, were computed and compared using Fisher's Exact Test. To consider the confounding factor of irradiated lung volume, patient subgroups were further defined on the basis of the mean lung dose.

RESULTS

Surgical procedures included pneumonectomy (n=9), lobectomy (n=16), wedge resection (n=8) and exploration without resection (n=16). Radiation-induced lung injury occurred in 33 out of 177 (19%) patients, including 18% of the surgical group and 19% of the non-surgical group. Additionally, no statistically significant difference was found in the rate of radiation-induced lung injury based on the extent of resection.

CONCLUSIONS

The incidence of pneumonitis is similar in the surgical and non-surgical groups. Thus, PORT may be safely given to selected patients after surgical exploration or resection.

Analysis of the drude model in metallic films

A method, believed to be new, to simulate Drude parameters for collective oscillation of the free carriers in metallic films is proposed. Plasma resonance frequency and relaxation were simulated simultaneously from both the real and the imaginary parts of the dielectric function of a metallic film after consideration of their correlation in the Drude model. As examples, the contributions of the electrons in Ag films and of the free carriers in metallic silicide, NbSi(2) and TaSi(2), films have been studied.

Radiation-induced pulmonary toxicity: a dose-volume histogram analysis in 201 patients with lung cancer

PURPOSE

To relate lung dose-volume histogram-based factors to symptomatic radiation pneumonitis (RP) in patients with lung cancer undergoing 3-dimensional (3D) radiotherapy planning.

METHODS AND MATERIALS

Between 1991 and 1999, 318 patients with lung cancer received external beam radiotherapy (RT) with 3D planning tools at Duke University Medical Center. One hundred seventeen patients were not evaluated for RP because of <6 months of follow-up, development of progressive intrathoracic disease making scoring of pulmonary symptoms difficult, or unretrievable 3D dosimetry data. Thus, 201 patients were analyzed for RP. Univariate and multivariate analyses were performed to test the association between RP and dosimetric factors (i.e., mean lung dose, volume of lung receiving >or=30 Gy, and normal tissue complication probability derived from the Lyman and Kutcher models) and clinical factors, including tobacco use, age, sex, chemotherapy exposure, tumor site, pre-RT forced expiratory volume in 1 s, weight loss, and performance status.

RESULTS

Thirty-nine patients (19%) developed RP. In the univariate analysis, all dosimetric factors (i.e., mean lung dose, volume of lung receiving >or=30 Gy, and normal tissue complication probability) were associated with RP (p range 0.006-0.003). Of the clinical factors, ongoing tobacco use at the time of referral for RT was associated with fewer cases of RP (p = 0.05). These factors were also independently associated with RP according to the multivariate analysis (p = 0.001). Models predictive for RP based on dosimetric factors only, or on a combination with the influence of tobacco use, had a concordance of 64% and 68%, respectively.

CONCLUSIONS

Dosimetric factors were the best predictors of symptomatic RP after external beam RT for lung cancer. Multivariate models that also include clinical variables were slightly more predictive.

Acute urinary toxicity following transperineal prostate brachytherapy using a modified Quimby loading method

PURPOSE

To examine the acute urinary toxicity following transperineal prostate implant using a modified Quimby loading method with regard to time course, severity, and factors that may be associated with a higher incidence of morbidity.

METHODS AND MATERIALS

One hundred thirty-nine patients with prostate adenocarcinoma treated with brachytherapy from 1997 through 1999 had follow-up records available for review. Patients considered for definitive brachytherapy alone included those with prostate specific antigen (PSA) < or = 6, Gleason score (GS) < or = 6, clinical stage < T2b, and prostate volumes generally less than 40 cc. Patients with larger prostate volumes were given neoadjuvant antiandrogen therapy. Those with GS > 6, PSA > 6, or Stage > T2a were treated with external beam radiation therapy followed by brachytherapy boost. Sources were loaded according to a modified Quimby method. At each follow-up, toxicity was graded based on a modified RTOG urinary toxicity scale.

RESULTS

Acute urinary toxicity occurred in 88%. Grade I toxicity was reported in 23%, grade II in 45%, and grade III in 20%, with 14% requiring prolonged (greater than 1 week) intermittent or indwelling catheterization. Overall median duration of symptoms was 12 months. There was no difference in duration of symptoms between patients treated with I-125 or Pd-103 sources (p = 0.71). After adjusting for GS and PSA, multivariate logistic regression analysis showed higher incidence of grade 3 toxicity in patients with larger prostate volumes (p = 0.002), and those with more seeds implanted (p < 0.001). Higher incidence of prolonged catheterization was found in patients receiving brachytherapy alone (p = 0.01), with larger prostate volumes (p = 0.01), and those with more seeds implanted (p < 0.001).

CONCLUSION

Interstitial brachytherapy for prostate cancer leads to a high incidence of acute urinary toxicity, most of which is mild to moderate in severity. A prolonged need for catheterization can occur in some patients. Patients receiving brachytherapy alone, those with prostate volumes greater than 30 cc, and those implanted with a greater number of seeds have the highest incidence of significant toxicity.

[The enlarged translabyrinthine removal of large acoustic neuromas: 18 cases report]

OBJECTIVE

To investigate the surgical methods and results of enlarged translabyrinthine approach in the removal of large acoustic neuromas.

METHOD

A large mastoidectomy involved complete exposure of sigmoid sinus, the dura behind the sinus for at least 1 cm, the superior petrosal sinus and the middle fossa dura. The jugular bulb was exposed and pressed downwards if necessary. The internal auditory meatus was skeletonized and uncovered for at least 270 degrees. The debulking of the tumor began inside the anterior and inferior poles in order to find the brainstem and the facial nerve root as early as possible, then the dissection of the nerve was performed medially to laterally. Intraoperative facial nerve monitoring and postoperative CT and MRI were performed in all cases.

RESULT

Total removal was achieved in all 18 patients with tumors larger than 3 cm (mean size: 4.2 cm). There were no death as well as other complications such as intracranial infection and persistent cerebrospinal fluid leakage. There were no obvious cerebral sequela. The facial nerve was preserved both anatomically and functionally in 14 cases, with Grade I or II in 8 cases, Grade III or IV in 6 cases. Nerve interruption occurred in 4 cases who all had severe facial paralysis or nerve interruption before operation. 16 patients returned to work within 1-3 months.

CONCLUSION

Total removal of large acoustic neuroma could be accomplished via the translabyrinthine approach, with good result of facial nerve function and minimum incidence of morbidity.

A new three-dimensional dose distribution reduction scheme for tubular organs

In tubular structures, spatial aspects of the dose distribution may be important in determining the normal tissue response. Conventional dose-volume-histograms (DVHs) and dose-surface-histograms (DSHs) lack spatial information and may not be adequate to represent the three-dimensional (3D) dose data. A new 3D dose distribution data reduction scheme which preserves its longitudinal and circumferential character is presented. Dose distributions were generated at each axial level for esophagus or rectum in 123 patients with lung cancer or prostate cancer. Dose distribution histograms at each axial level were independently analyzed along the esophageal or rectal circumference to generate dose-circumference-histogram (DCH) sheets. Two types of plots were then generated from the DCH sheet. The first considered the percentage of the circumference at each axial level receiving various doses. The second considered the minimum dose delivered to any percentage of the circumference at each axial level. The DCH as a treatment planning tool can be easily implemented in a 3D planing system and is potentially useful for the study of the relationship between the complication risk and the longitudinal and circumferential dose distributions.

Routine 3D treatment planning: opportunities, challenges, and hazards

Three-dimensional (3D) treatment planning refers to the use of software and hardware tools to design and implement more accurate and conformal radiation therapy. This is a major advance in oncology that should lead to the reduction of treatment-associated morbidity and facilitate safe dose escalation for many tumor sites. This technology affords the incorporation of physiologic and anatomic information into the treatment planning process, further enhancing our ability to improve the therapeutic ratio. However, as with any new technology, care must be taken when applying it in the clinic. The introduction of 3D planning presents new challenges to existing quality assurance systems. These need to be addressed to maintain patient safety. Based on our experience with over 1,500 patients treated at Duke University, the benefits, challenges, and hazards of routine 3D treatment planning are discussed.

[The semiconductor diode laser application in tympanoplasty]

OBJECTIVE

To investigate the method, indications and initial results of semiconductor diode laser application in tympanoplasty.

METHOD

The diode laser was used in 14 tympanoplasty procedures. The laser manipulation was mainly used in cases of malleus and incus bony fixation with the tympanum, the fibrous scar tissue around the ossicular chain and the malleus head resection.

RESULT

There was no postoperative vertigo and facial paralysis. The average hearing improvement was 24 dB. Seven cases (50%) reached an air-bone gap within 20 dB.

CONCLUSION

The application of diode laser in tympanoplasty could effectively reduce the manipulation trauma of ossicular chain and control the bleeding of operative field, especially in managing the bony adhesion of the ossicular chain.

Asymmetry in elementary events of magnetization reversal in a ferromagnetic/antiferromagnetic bilayer

Real-time magneto-optical indicator film images reveal distinct asymmetry in the motion of a single domain wall in a wedged-NiFe/uniform-FeMn bilayer due to the nucleation and behavior of an exchange spring in the antiferromagnetic layer. Magnetization reversal from the ground state begins at the thick end of the wedge where the exchange anisotropy field (HE) is minimal and the magnetostatic field (HMS) is maximal, whereas reversal into the ground state begins from the thin end where HE is maximal and HMS is minimal.

Clinical and dosimetric predictors of radiation-induced esophageal toxicity

PURPOSE

To evaluate the incidence, severity, and clinical/dosimetric predictors of acute and chronic esophageal toxicities in patients with non-small cell lung cancer (NSCLC) treated with high-dose conformal thoracic radiation.

METHODS AND MATERIALS

Ninety-one patients with localized NSCLC treated definitively with high-dose conformal radiation therapy (RT) at Duke University Medical Center (DUMC) were reviewed. Patient characteristics were as follows: 53 males and 38 females; median age 64 yr (range 46-82); stage I--16, II--3, IIIa--40, IIIb--30, X--2; dysphagia pre-RT--6 (7%). Treatment parameters included: median corrected dose-78.8 Gy (range 64.2-85.6); BID fractionation-58 (64%); chemotherapy-43 (47%). Acute and late esophageal toxicities were graded by RTOG criteria. Using 3D treatment planning tools, the esophagus was contoured in a uniform fashion, the 3D dose distribution calculated (with lung density correction), and the dose-volume (DVH) and dose-surface histograms (DSH) generated. At each axial level, the percentage of the esophageal circumference at each dose level was calculated. The length of circumferential esophagus and the maximum circumference treated to doses >50 Gy were assessed. Patient and treatment factors were correlated with acute and chronic esophageal dysfunction using univariate and multivariate logistic regression analyses.

RESULTS

There were no acute or late grade 4 or 5 esophageal toxicities. Ten of 91 patients (11%) developed grade 3 acute toxicity. On univariate analysis of clinical parameters, both dysphagia pre-RT (p = 0.10) and BID fractionation (p = 0.11) tended toward significantly predicting grade 3 acute esophagitis. None of the dosimetric parameters analyzed significantly predicted for grade 3 acute esophagitis. Twelve of 66 assessable patients (18%) developed late esophageal toxicity. Of the clinical parameters analyzed, only dysphagia pre-RT (p = 0.06) tended toward significantly predicting late esophageal toxicity. On univariate analyses, the effects of percent organ volume treated >50 Gy (p = 0.05), percent surface area treated >50 Gy (p = 0.05), length of 100% circumference treated >50 Gy (p = 0.04), and maximum percent of circumference treated >80 Gy (p = 0.01) significantly predicted for late toxicity of all grades. On multivariate analysis, percent organ volume treated >50 Gy (p = 0.02) and maximum percent of circumference treated >80 Gy (p = 0.02) predicted for late toxicity.

CONCLUSIONS

Late esophageal toxicity following aggressive, high-dose conformal radiotherapy is common but rarely severe. Dosimetric variables addressing the longitudinal and circumferential character of the esophagus have biologic rationale and are predictive of late toxicity. Further studies are needed to assess whether these parameters are better predictors than those derived from traditional DVHs.

[Repair of recurrent laryngeal nerve injuries after thyroidectomy]

OBJECTIVE

In order to investigate the opportunity of repair and prognosis of recurrent laryngeal nerve injuries after thyroidectomy.

METHODS

Twelve cases with recurrent laryngeal nerve injuries after thyroidectomy were immediately and delayed operated on nerve repair and reinnervation. In immediate operation, 5 cases were repaired by direct recurrent laryngeal nerve suture, and 1 case was treated by transposition of the phrenic nerve to the recurrent laryngeal nerve and sutured the adductor branch to the branch of ansa cervicalis. In delayed operation, 3 cases were treated by anastomosis the main trunk of ansa cervicalis to the adductor branch of recurrent laryngeal nerve, and 3 cases were operated on neuromuscular pedicle to reinnervate posterior cricoarytenoid muscle.

RESULTS

Followed up 6 months, the effect was excellent in 1 case who was immediately operated by selective reinnervation of the abductor and adductor muscles of the larynx, better in 9 cases, and poor in 2 cases who were delayed operated over 12 months.

CONCLUSION

It can be concluded that the earlier reinnervation is performed, the better prognosis is.

Conformal radiation therapy treatment planning reduces the dose to the optic structures for patients with tumors of the paranasal sinuses

PURPOSE

Compare dose distributions of traditional versus conformal beam orientations in paranasal sinus malignancies.

MATERIALS AND METHODS

Maximum normal tissue doses, dose volume histograms (DVH), normal tissue complication probabilities (NTCP), and the percentage of each normal tissue receiving >80% of the average target dose (V80) were calculated.

RESULTS/CONCLUSIONS

Conformal planning reduced the V80 to the optic nerves and chiasm as well as the normal tissue maximum doses to the ipsilateral and contralateral optic nerves and chiasm, and mean NTCPs.

The effect of lanthanide chloride on abscisic acid and electron-transport activity of some crops

The abscisic acid (ABA) content of the root tips of four crops grown in lanthanide chloride solution and their root lengths had been determined. At lanthanide concentrations of 5 and 10 ppm, these crops all grew well and the ABA decreased. At higher lanthanide concentrations (100-500 ppm), the ABA is increased again. At these concentrations of lanthanum chloride, the photosystems I and II (PSI and PSII) and whole electron chain transport activities were inhibited. PSII was more sensitive than PSI, and it is concluded that La3+ acts on the diphenylcarbazide (DPC) action place of PSII oxidizing site.

A robust method of multileaf collimator (MLC) leaf-configuration verification

Presents a novel and robust method for leaf-position verification with a multileaf collimator (MLC). On the portal image associated with an MLC-generated treatment field, all true treatment-held-edge lines are either parallel or perpendicular to each other. This unique feature of an MLC treatment field has been fully exploited by the authors' method. Employing a Hough-type transformation as an edge-line-orientation detector and a chamfer-matching method, the authors can find the best matching parameters (including translation, rotation and scaling) adaptively between a prescribed MLC leaf configuration and the actual treatment-held edges generated by the MLC system. This works even if the portal image is partially corrupted by noise or covered by compact bony structures. Comparing these parameters with clinically accepted tolerances, the authors can make a "go-or-no-go" decision quickly.

The effect of Epstein-Barr virus gene BHRF1 expression on radioresistance of nasopharyngeal carcinoma cells

In order to investigate the effect of the expression of Epstein-Barr virus gene BHRF1 on the apoptotic resistance of nasopharyngeal carcinoma cells to radiation, a highly expressing vector for BHRF1 was constructed and transfected into the nasopharyngeal carcinoma cell line CNE2. Then, the biologic alterations of the cells were tested after 60Co radiation. The results showed that, in the BHRF1-expressing cells, the apoptotic index was far lower than in the control groups after 60Co radiation, and cells recovered faster from the radiation, with a higher cell-proliferative rate, stronger ability of colony formation and tumor development in nude mice than that in the control groups. Given the functional homology of BHRF1 with bcl-2, our data indicate that BHRF1 expression could prohibit nasopharyngeal carcinoma cellular apoptosis caused by radiation and in this way contribute to oncogenic transformation.

Differences in gross target volumes on contrast vs. noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma

PURPOSE

To compare the gross target volumes (GTVs) (prostate and seminal vesicles) defined on noncontrast and contrast-enhanced computed tomography (CT) images used for three-dimensional conformal treatment planning (3DCRT).

METHODS AND MATERIALS

From 1993 to 1996, 39 patients referred for radiation therapy for adenocarcinoma of the prostate underwent pretreatment pelvic CT scanning with and without intravenous (i.v.) contrast for treatment planning purposes. Seven patients were excluded because of incomplete data sets. The prostate and seminal vesicles were outlined by the same physician on all images of 32 patients. On 18 CT exams, the prostate and seminal vesicles were blindly outlined a second time by the same physician to evaluate intraphysician consistency. Discrepancies between the GTVs outlined with and without contrast and between the first and second outline on the same study were assessed by calculating the projected area in the anterior-to-posterior (AP) and right lateral (RLAT) beam's-eye view (BEV). To assess the magnitude, frequency, and direction of discrepancies between the two GTVs, the extension of the GTVs in six directions (right, left, anterior, posterior, cephalad, and caudal) was determined.

RESULTS

The GTV outlined with contrast was larger in all directions, except caudal, in the majority of patients. The change in the GTV with contrast was significant in the cephalad (p=0.0003) and right (p=0.0007) directions, but not in the other directions. Although the increase with contrast in any direction was usually small (average < or =5 mm), these changes resulted in a significant increase in GTV area in both the AP and RLAT BEV (9.0%, p=0.0017 and 8.2%, p=0.023, respectively). The intraphysician variability in outlining the prostate/ seminal vesicles was minimal.

CONCLUSIONS

The addition of i.v. contrast does appear to make a significant difference in how the prostate and seminal vesicles are outlined by an experienced observer. The increase in area of the target, found when contrast is used, should be taken into consideration when designing the treatment fields for patients with carcinoma of the prostate.