[Study on the mechanism of early pancreatic exocrine function changes in severely scalded rats]

Objective: To explore the mechanism of early pancreatic exocrine function changes in severely scalded rats. Methods: The experimental research methods was used. Eighty male Sprague-Dawley rats aged 7-8 weeks were divided into simple sham injury group (n=8), sham injury+cholecystokinin octapeptide (CCK8) group (n=8), severe scald+CCK8 group (n=32), and extremely severe scald+CCK8 group (n=32) by the random number table, which were treated accordingly. Immediately after injury of rats in the 2 sham injury groups and 1, 2, 3, and 7 days after injury of rats in the 2 scald groups, the improved methods including pancreatic duct puncture and catheterization were used to dynamically collect the pancreatic-bile juice (PBJ) of rats. The PBJ secretory volume within 1 h was recorded, and the content of pancreatic lipase, α-amylase, and trypsin in PBJ was detected by enzyme-linked immunosorbent assay (ELISA), and the number of samples was 8. The femoral venous blood was collected, and the concentrations of pancreatic lipase and α-amylase in serum were detected by standard colorimetry to reflect their activity (n=8). The pancreatic tissue was extracted, and the levels of interleukin-1β (IL-1β) and IL-6 in pancreatic tissue were detected by ELISA (n=8), the expression of hypoxia-inducible factor 1α (HIF-1α) in pancreatic tissue was detected by immunofluorescence method, and the histopathological changes in pancreatic tissue were observed by hematoxylin-eosin staining, the severity of pancreatic tissue injury in the 2 scald groups was evaluated by modified Schmidt method (n=6), and the ultrastructure of acinar cells in pancreatic tissue was observed by transmission electron microscopy. Data were statistically analyzed with analysis of variance for factorial design, Tukey test, independent sample t test, and least significant difference test. Results: Compared with the PBJ secretory volume (0.740±0.030) mL in the pancreatic tissue of rats in simple sham injury group within 1 h immediately after injury, the (0.823±0.033) mL in sham injury+CCK8 group was significantly increased (t=4.92, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the PBJ secretory volume of rats within 1 h in severe scald+CCK8 group ((0.681±0.024), (0.608±0.056), (0.525±0.025), and (0.720±0.044) mL) and extremely severe scald+CCK8 group ((0.540±0.025), (0.406±0.021), (0.475±0.036), and (0.690±0.018) mL) was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the PBJ secretory volume of rats within 1 h in extremely severe scald+CCK8 group was significantly decreased on 1 and 2 days after injury (P<0.05). Compared with that of rats in simple sham injury group immediately after injury, the content of pancreatic lipase, α-amylase, and trypsin in PBJ of rats in sham injury+CCK8 group immediately after injury was significantly increased (with t values of 4.56, 3.30, and 4.99, respectively, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the content of pancreatic lipase and α-amylase in PBJ of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05), the trypsin content in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 2 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the content of pancreatic lipase in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 1, 2, and 3 days after injury (P<0.05), and the content of α-amylase and trypsin in PBJ was significantly decreased on 1 and 2 days after injury (P<0.05). There were no statistically significant differences in the activities of pancreatic lipase and α-amylase in serum of rats among the 4 groups at various time points after injury (P>0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the levels of IL-1β in pancreatic tissue of rats in severe scald+CCK8 group on 1, 2, and 3 days after injury and in extremely severe scald+CCK8 group on 1, 2, 3, and 7 days after injury were significantly increased (P<0.05), and the levels of IL-6 in pancreatic tissue of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group were significantly increased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the IL-1β level in pancreatic tissue of rats in extremely severe scald+CCK8 group was significantly increased on 2 and 3 days after injury (P<0.05), and IL-6 level in pancreatic tissue was significantly increased on 2 days after injury (P<0.05). The expression levels of HIF-1α in pancreatic tissue of rats in simple sham injury group and sham injury+CCK8 group immediately after injury were lower; and compared with that in sham injury+CCK8 group immediately after injury, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups increased to a certain extent at different time points after injury, and the expression position was transited from the edge of the pancreatic tissue to the whole pancreas, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups tended to be normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the proportion of acinar cell cytoplasm in pancreatic tissue of rats in sham injury+CCK8 group was increased; and with the increase of time after injury, edema, hemorrhage, necrosis, and inflammatory infiltration appeared in pancreatic tissue of rats in the 2 scald groups. Compared with that in severe scald+CCK8 group, the scores of edema, inflammatory cell infiltration, bleeding, and necrosis in pancreatic tissue of rats in extremely severe scald+CCK8 group were increased to varying degrees at various time points after injury, and the scores of pancreatic tissue of rats in the 2 scald groups basically recovered to normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the number of enzyme granules in acinar cells of pancreatic tissue of rats in sham injury+CCK8 group was increased, and with the increase of time after injury, the enzyme granules in acinar cells of rats in the 2 scald groups were gradually reduced basically. Conclusions: The exocrine functions of pancreas, such as synthesis and secretion of pancreatic enzymes, are decreased in the early stage in severely scalded rats. And the greater the scalded area, the more significant the decline of pancreatic exocrine function. This change may be related to hypoxic injury and inflammation in pancreatic tissue after severe scald.

Negative correlations between bile reflux gastritis and Helicobacter pylori infection

OBJECTIVE

There are a few articles to study the relationship between bile reflux gastritis (BRG) and H. pylori infection, and the results are debatable. This study set out to determine the relationship between BRG and Helicobacter pylori (H. pylori) infection.

METHODS

In this retrospective study, patients from January, 1st 2013 to January, 1st, 2021 were divided into two groups based on whether they had BRG. The control group was got by 1:1 propensity-score matching (PSM) based on age and sex. Then, the relationship between BRG and H. pylori in patients was analyzed via Chi-squared test and Phi (φ) detection.

RESULTS

26449 patients were included in this study, and there were 1918 patients in each group after age and sex matching. patients with HP were responsible for 35% (9345/26449) and patients with BRG were 7% (1918/26449). Further relationship exploration, there is a negative, but weak, the relationship between BRG and HP infection (X² = 45.62, p < .001, Phi (φ)= -0.109).

CONCLUSION

Patients with bile reflux may have less likely to get HP infection. HP eradication is an important thing for the prevention of gastric cancer and this study serves as a foundation and may provide directions for future research.

Risk of thyroid cancer and benign nodules associated with exposure to parabens among Chinese adults in Wuhan, China

Parabens are widely used as preservatives, which have been found to affect thyroid function in toxicological studies. However, population studies on whether they are associated with thyroid tumors remain unclear. This study aims to investigate the relationship between environmental paraben exposure and thyroid cancer and benign nodules. We recruited participants from the Department of Thyroid and Breast Surgery at Wuhan Central Hospital, Wuhan, China. The detectable percentages of methyl paraben, ethyl paraben, and propyl paraben in the urinary samples of 425 study subjects were 99.1%, 95.3%, and 92.0%, respectively. All uncorrected and creatinine-corrected parabens were moderately correlated with one another. After adjusting for possible confounders, all three parabens were associated with an increased risk of thyroid cancer. Furthermore, the mixture pollutant analysis of parabens found positive associations with risk of thyroid cancer (OR = 0.24, 95% CI: 0.18, 0.31) and benign nodules (OR = 1.33, 95% CI: 0.86, 1.80). We observed that individual exposure to paraben mixtures may be associated with the risk of thyroid cancer and benign nodules.

[Research advances on the role and mechanism of epidermal stem cells in skin wound repair]

Epidermal stem cells play an pivotal role in skin self-renewal, wound repair, and re-epithelialization process. The emergence of new technologies and concepts such as single-cell sequencing and gene knockout further revealed a new mechanism of epidermal stem cells in epidermal self-renewal and wound repair, providing new ideas for wound repair. In this review, the mechanisms of proliferation, differentiation, and migration of epidermal stem cells are discussed. Combined with the analysis of researches on stem cell heterogeneity and cell plasticity, the physiological function of epidermal stem cells can be further understood. The application advances of epidermal stem cells in wound repair is also summarized, which would provide some advice for workers engaged in clinical and basic research on wound repair.

[Effects of collagen type ⅩⅦ α1 on epidermal stem cells in aging skin and the microRNA intervention mechanism]

Objective: To investigate the expression and function of collagen type ⅩⅦ α1 (COL17α1) in aging mouse skin and its effect on the stemness and proliferation of human epidermal stem cells (ESCs), and to explore the mechanism of related microRNA (miR) in intervening the expression of COL17α1 of human ESC. Methods: The method of experimental research was used. Twelve 2-month-old (young) and twelve 24-month-old (aged) male C57BL/6J mice were selected, and full-thickness skin samples from their upper back were taken for follow-up detection. After hematoxylin-eosin staining of the full-thickness skin samples of young mice and aged mice, the structure of the epidermis was observed and the thickness of the epidermis was measured; the morphology of epidermal basement membrane and hemidesmosomes were observed by transmission electron microscopy, and the hemidesmosomes were counted; the mRNA and protein expressions of COL17α1 were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively, and the protein expression and distribution of COL17α1 was observed and detected by immunofluorescence method. The fresh foreskin tissue discarded after surgery was obtained from 3 healthy men aged 20-30 years who underwent circumcision at the Fourth Medical Center of PLA General Hospital, ESCs were extracted and well-grown cells were wsed for follow-up experiments. According to the random number table (the same grouping method below), ESCs were divided into blank control group, transfection reagent control group, empty vector plasmid group, and COL17α1 knockdown plasmid group with corresponding treatment. After 48 hours of culture, the mRNA expression of COL17α1 was detected by real-time fluorescent quantitative RT-PCR, the protein expressions of COL17α1 and cytokeratin 14 (CK14) were detected by Western blotting, and the cell proliferation level was detected by cell counting kit 8. miRs that might act on the 3' non-coding region of COL17α1 mRNA were screened through DIANA, miRTarBase, miRNAMap, TargetScan, and microRNA databases. The ESCs were divided into negative control group transfected with miR mimic negative control and each miR mimic group transfected with each of the previously screened miR mimics. Forty-eight hours after transfection, the protein expression of COL17α1 was detected by Western blotting. Based on the sequencing data set GSE114006 in Gene Expression Omnibus (GEO), the GEO2R tool was used to statistically analyze the expression of the previously screened miRs that could cause the reduction of COL17α1 protein expression in the skin of 30 young (18-25 years old) and 30 elderly (>70 years old) human skins. The full-thickness skin samples of young mice and aged mice were taken, and the expressions of increased miRs in the aforementioned aged human skin were detected by real-time fluorescent quantitative RT-PCR. Two batches of human ESCs were taken, the first batch was divided into COL17α1 wild type+miR-203b-3p negative control group and COL17α1 wild type+miR-203b-3p mimic group, and the second batch was divided into COL17α1 mutant+miR-203b-3p negative control group and COL17α1 mutant+miR-203b-3p mimic group. Each group of ESC was transfected with corresponding sequences respectively. Forty-eight hours later, the luciferase reporter gene detection kit was used to detect the gene expression level of COL17α1. The number of samples in the tissue experiment was 6, and the number of samples in the cell experiment was 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, least significant difference test or Dunnett's test, Mann-Whitney U test or Kruskal-Wallis H test. Results: Compared with those of young mice, the boundary between the epidermis and the dermis of the aged mice skin was blurred and the cell layers were less, and the thickness of epidermis was significantly thinner (Z=-2.88, P<0.01); the morphology of basement membrane was discontinuous, with less unevenly distributed hemidesmosomes at the epidermis-dermis junction, and the number of hemidesmosomes was significantly reduced (Z=-2.91, P<0.01); the mRNA and protein expression levels of COL17α1 in the skin of aged mice were significantly decreased (with t values of 10.61 and 6.85, respectively, P<0.01). Compared with those of young mice, the protein expression of COL17α1 in the basal layer of epidermis and the bulb of hair follicle in the skin of aged mice was significantly decreased (Z=-2.24, P<0.05). After 48 hours of culture, the protein expression levels of COL17α1 in ESCs of blank control group, transfection reagent control group, empty vector plasmid group, and COL17α1 knockdown plasmid group were 1.00±0.27, 1.12±0.21, 1.13±0.23, and 0.42±0.18, respectively. Compared with those of blank control group, the mRNA and protein expression levels of COL17α1, the protein expression level of CK14, and the proliferation level of ESCs in transfection reagent control group and empty vector plasmid group did not change significantly (P>0.05), while these indexes in COL17α1 knockdown plasmid group were significantly decreased (P<0.05 or P<0.01). miR-203a-3p, miR-203b-3p, miR-512-5p, miR-124-3p, miR-28-5p, miR-590-3p, and miR-329-5p might bind to the 3' non-coding region of COL17α1 mRNA. Forty-eight hours after transfection, compared with 1.000±0.224 in negative control group, the protein expression level of COL17α1 in ESCs of miR-329-5p mimic group, miR-203b-3p mimic group, and miR-203a-3p mimic group decreased significantly (0.516±0.188, 0.170±0.025, and 0.235±0.025, with t values of 3.17, 5.43, and 5.07, respectively, P<0.05 or P<0.01). Only the expression level of miR-203b-3p in the skin of the elderly was significantly higher than that of the young (t=3.27, P<0.01). The expression level of miR-203b-3p in the skin of aged mice was significantly higher than that of young mice (Z=-2.88, P<0.01). Forty-eight hours after transfection, the gene expression level of COL17α1 in ESCs of COL17α1 wild type+miR-203b-3p mimic group was significantly lower than that of COL17α1 wild type+miR-203b-3p negative control group (t=7.66, P<0.01). The gene expression level of COL17α1 in ESCs of COL17α1 mutant+miR-203b-3p mimic group was similar to that of COL17α1 mutant+miR-203b-3p negative control group (P>0.05). Conclusions: The mRNA and protein expression levels of COL17α1 decrease with age increasing in mice, which may lead to the detachment of mouse ESC from the epidermal basement membrane. Decreased expression of COL17α1 can inhibit the expression of CK14 and ESC proliferation, which may be responsible for the thinning of the epidermis and slower wound healing in aged human skin. The increased expression of miR-203b-3p in aged mouse skin can target and bind to the 3' non-coding region of COL17α1 mRNA, hindering the post-transcriptional translation process, thus resulting in decreased COL17α1 protein expression.

[Spectral CT multi-parameter imaging in preoperatively evaluation the status of lymphovascular and perineural invasion of gastric cancer]

Objective: To explore the application value of spectral CT multi-parameter imaging in preoperative assessment the status of lymphovascular invasion (LVI) and perineural invasion (PNI) in patients with gastric cancer. Methods: A total of 62 patients who underwent energy spectral CT and with pathology confirmed gastric cancer in Lanzhou Uiversity Second Hospital from September 2020 to September 2021 were retrospectively collected, which including 46 males and 16 females, aged from 36 to 71 (57.5±9.1) years. According to the presence or absence of LVI/PNI in postoperative pathological results, they were divided into the positive group (42 cases) and the negative group (20 cases). The CT values of 40 keV and 70 keV (CT_{40 keV}, CT_{70 keV}), iodine concentration (IC), normalized iodine concentration (NIC) were measured in the arterial phase, the venous phase, and the delay phase, and the spectral curve slope of 40 keV to 70 keV (K_(40-70)) and the combined parameters (the arterial phase: AP~all, the venous phase: VP~all, the delay phase: DP~all) were calculated. Spectral parameters between the positive and negative groups were compared, and the receiver operating characteristic curve (ROC) with the area under the curve (AUC), sensitivity, specificity, and optimal threshold were calculated for evaluating the diagnostic performance of each parameter. Results: The CT_{40 keV}, CT_{70 keV}, K_(40-70), IC, and NIC in the arterial phase and the venous phase and the CT_{70 keV} and NIC in the delay phase of the LVI/PNI-positive group were all higher than those of the negative group [the representative parameters: the arterial phase NIC 0.14±0.04 vs 0.12±0.04, the venous phase NIC 0.5(0.5, 0.6) vs 0.4(0.4, 0.5), the delay phase NIC 0.6±0.1 vs 0.5±0.1, all P<0.05]. ROC curve analysis showed that the diagnostic efficacy of the parameters of the venous phase is better than that of the arterial phase and the delay phase, and the diagnostic efficiency of the combined parameters is better than that of the individual parameters. The AUC value, sensitivity, and specificity of the most optimal parameter VP~all of the venous phase were 0.931(95%CI:0.872-0.990), 80.95%, and 95.00%, respectively. Conclusions: In the preoperative evaluation the status of the LVI and PNI in gastric cancer, the diagnostic efficacy in the venous phase parameters is better than that in the arterial phase and delay phase, and the diagnostic efficacy of combined parameters is better than that of individual parameters.

Multi-Organ Omics-Based Prediction for Adaptive Radiation Therapy Eligibility in Nasopharyngeal Carcinoma Patients Undergoing Concurrent Chemoradiotherapy

Purpose

To investigate the role of different multi-organ omics-based prediction models for pre-treatment prediction of Adaptive Radiotherapy (ART) eligibility in patients with nasopharyngeal carcinoma (NPC).

Methods and Materials

Pre-treatment contrast-enhanced computed tomographic and magnetic resonance images, radiotherapy dose and contour data of 135 NPC patients treated at Hong Kong Queen Elizabeth Hospital were retrospectively analyzed for extraction of multi-omics features, namely Radiomics (R), Morphology (M), Dosiomics (D), and Contouromics (C), from a total of eight organ structures. During model development, patient cohort was divided into a training set and a hold-out test set in a ratio of 7 to 3 via 20 iterations. Four single-omics models (R, M, D, C) and four multi-omics models (RD, RC, RM, RMDC) were developed on the training data using Ridge and Multi-Kernel Learning (MKL) algorithm, respectively, under 10-fold cross validation, and evaluated on hold-out test data using average area under the receiver-operator-characteristics curve (AUC). The best-performing single-omics model was first determined by comparing the AUC distribution across the 20 iterations among the four single-omics models using two-sided student t-test, which was then retrained using MKL algorithm for a fair comparison with the four multi-omics models.

Results

The R model significantly outperformed all other three single-omics models (all p-value<0.0001), achieving an average AUC of 0.942 (95%CI: 0.938-0.946) and 0.918 (95%CI: 0.903-0.933) in training and hold-out test set, respectively. When trained with MKL, the R model (R_MKL) yielded an increased AUC of 0.984 (95%CI: 0.981-0.988) and 0.927 (95%CI: 0.905-0.948) in training and hold-out test set respectively, while demonstrating no significant difference as compared to all studied multi-omics models in the hold-out test sets. Intriguingly, Radiomic features accounted for the majority of the final selected features, ranging from 64% to 94%, in all the studied multi-omics models.

Conclusions

Among all the studied models, the Radiomic model was found to play a dominant role for ART eligibility in NPC patients, and Radiomic features accounted for the largest proportion of features in all the multi-omics models.

Iodine-imine Synergistic Promoted Povarov-Type Multicomponent Reaction for the Synthesis of 2,2'-Biquinolines and Their Application to a Copper/Ligand Catalytic System

An efficient iodine-imine synergistic promoted Povarov-type multicomponent reaction was reported for the synthesis of a practical 2,2'-biquinoline scaffold. The tandem annulation has reconciled iodination, Kornblum oxidation, and Povarov aromatization, where the methyl group of the methyl azaarenes represents uniquely reactive input in the Povarov reaction. This method has broad substrate scope and mild conditions. Furthermore, these 2,2'-biquinoline derivatives had been directly used as bidentate ligands in metal-catalyzed reactions.

[Changes of insulin secretion and its signal transduction mechanism at early stage of severe scald in rats]

Objective: To observe the changes of insulin secretion in the early stage of severe scald in rats, and to explore its signal transduction mechanism. Methods: Twenty-four male Wistar rats aged 7 weeks were divided into sham injury alone (SIA) group, sham injury+ BPV (HOpic) (SIB) group, scald alone (SA) group, and scald+ BPV (HOpic) (SB) group using the random number table, with 6 rats in each group. Full-thickness scald of 50% total body surface area was inflicted in rats of SA and SB groups by a 6-s immersion of the abdomen and a 12-s immersion of the back in 94 ℃ hot water. Rats in SIA and SIB groups received sham injuries through immersion of the back and abdomen in 37 ℃ warm water for 6 and 12 seconds respectively. From 0 (immediately) to 2 day (s) after injury, the rats in groups SB and SIB were intraperitoneally injected with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway enhancer BPV (HOpic) solution (0.5 mg/mL) at the dosage of 0.6 mg/kg once a day, and the rats in groups SA and SIA were intraperitoneally injected with the same volume of dimethyl sulfoxide once a day. At post injury hour (PIH) 72, the tail blood of rats was sampled for measuring fasting blood glucose (FBG) with a glucometer, and the pancreatic tissue samples of rats was harvested for observing the pathological manifestations of islets by hematoxylin-eosin staining, counting the docked granules per 10 μm membrane of islet beta cells and calculating the proportion of insulin vesicles through the observation of the ultrastructure of islet beta cells by transmission electron microscope, and detecting the phosphorylation level of Akt in the pancreatic PI3K/Akt signaling pathway by Western blotting. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: (1) At PIH 72, the rat FBG levels in SIA and SIB groups were normal and similar (P>0.05). Compared with the levels of those two groups, the rat FBG level in SA group was increased significantly (P<0.01), while the level in SB group showed no obvious change (P>0.05). Compared with that in SA group, the rat FBG level in SB group was decreased significantly (P<0.01). (2) At PIH 72, the morphology of rat islets was complete and the islet cells distributed regularly in SIA and SIB groups. Compared with those in SIA and SIB groups, the morphology of rat islets was incomplete, the insulin vesicles in islets were common, the islet cells distributed irregularly, and the cytoplasm of some islet beta cells was lightly stained or translucent in SA group; the morphology of islets in SB group did not change obviously. Compared with those in SA group, the morphology of islets was comparatively complete, the insulin vesicles in islets were less common, the islet cells distributed comparatively regularly, and the lightly stained or translucent cytoplasm of islet beta cells was less in SB group. (3) At PIH 72, the number of docked granules per 10 μm membrane of rat islet beta cells and the proportion of insulin vesicles in SIA and SIB groups were similar (P>0.05). Compared with those in SIA and SIB groups, the number of docked granules per 10 μm membrane of rat islet beta cells in SA group was decreased significantly (P<0.01), while the proportion of insulin vesicles was increased significantly (P<0.01); the number of docked granules per 10 μm membrane of rat islet beta cells in SB group was obviously decreased (P<0.05), while the proportion of insulin vesicles did not change obviously (P>0.05). Compared with those in SA group, the number of docked granules per 10 μm membrane of rat islet beta cells in SB group was significantly increased (P<0.01), while the proportion of insulin vesicles was significantly decreased (P<0.01). (4) At PIH 72, the phosphorylation levels of Akt in SIA, SIB, SA, and SB groups were 0.91±0.03, 0.98±0.03, 0.78±0.08, and 0.87±0.08, respectively. Compared with that in SIA group, the phosphorylation level of Akt was increased obviously in SIB group (P<0.05) but was decreased significantly in SA group (P<0.01), while the level in SB group did not change obviously (P>0.05). Compared with the level in SIB group, the phosphorylation levels of Akt in SA and SB groups were decreased significantly (P<0.01). Compared with that in SA group, the phosphorylation level of Akt in SB group was increased significantly (P<0.05). Conclusions: At the early stage post severe scald in rats, the activity of the pancreatic PI3K/Akt signaling pathway and the function of insulin secretion are reduced. Improving the activity of the pancreatic PI3K/Akt signaling pathway in rats can ameliorate the function of insulin secretion and recover the physiological level of blood glucose.

Insight into miRNAs related with glucometabolic disorder

A microRNA (miRNA) is a single-stranded, small and non-coding RNA molecule that contains 20-25 nucleotides. More than 2000 miRNAs have been identified in human genes since the first miRNA was discovered in Caenorhabditis elegans in the early 1990s. miRNAs play a crucial role in various biological processes by regulating gene expression through post-transcriptional mechanisms. The alterations of their levels are associated with various diseases, such as glucometabolic disorder and lipid metabolism disorder. In recent years, miRNAs have been proved to be involved in regulating the functions of pancreatic β-cells, insulin resistance and other biological behaviors related to glucometabolic disorder and the pathogenesis of diabetes mellitus (DM). This review summarized specific miRNAs, including miRNA-375 (miR-375), miRNA-155 (miR-155), miRNA-21 (miR-21), miRNA-33 (miR-33), the let-7 family and some other miRNAs related to glucometabolic regulation, introduced the obstacles and challenges in miRNA therapy, and discussed the prospect of new treatment methods for glucometabolic disorder.

[Triptolide reverses apatinib resistance in gastric cancer cell line MKN45 via inhibition of heat shock protein 70]

Objective: To investigate the effect of triptolide, a specific inhibitor of heat shock protein 70 (HSP70), on apatinib resistance in gastric cancer cells line MKN45. Methods: The apatinib-resistant cells (MKN45/AR) and MKN45 parental cells were treated with apatinib, triptolide and apatinib combined with triptolide, respectively. CCK-8 assay was performed to determine the half maximal inhibitory concentration (IC(50)) of MKN45/AR and MKN45 cells in the presence of different treatment. The mRNA expression of heat shock protein gene (HSPA1A and HSPA1B) was detected by RT-PCR, while the protein expression of heat shock protein 70 was analyzed using Western blot in MKN45/AR and MKN45 cells. Results: The IC(50) values of apatinib-sensitive and apatinib-resistant MKN45 cells were 10.411 μmol/L and 70.527 μmol/L, respectively, showing a significant difference (P<0.05). The mRNA expression of HSPA1A and HSPA1B in MKN45/AR cells was significantly higher than that in MKN45 cells (P<0.001). The protein expression of heat shock protein 70 was significantly decreased after 0.25 μmol/L triptolide treatment in MKN45/AR cells (P<0.01). When heat shock protein 70 was inhibited by triptolide, the IC(50) value of apatinib in MKN45/AR cells was reduced to 11.679 μmol/L, which was significantly lower than cells treated with apatinib alone (P<0.05). Conclusions: The apatinib-resistant MKN45 cells have high levels of heat shock protein 70. Low doses of triptolide can significantly inhibit heat shock protein 70, leading to reverse the resistance phenotype of MKN45/AR cells. Therefore, inhibition of heat shock protein 70 provides a new therapy strategy for patients with apatinib resistance.

Abstract P5-07-03: GD2-mediated FAK signaling regulates breast cancer stem cell function in triple negative breast cancer

Ganglioside GD2 identifies breast cancer stem cells (BCSCs, Battula et al., JCI, 2012) and expression of GD2 is tightly regulated by GD3 synthase (GD3S). GD3S is highly expressed in GD2+ cells and inhibition of GD3S inhibits tumor formation and metastasis of breast cancer cells. However, the mechanism of GD2-mediated regulation of BCSC function is not known. Here we hypothesize that GD2 regulates signaling pathways involved in cell adhesion, migration and invasion of breast cancer cells. To identify these signaling pathways, antibody micro-arrays were used with 850 validated antibodies specific to total or phosphorylated proteins. Interestingly, focal adhesion kinase (FAK) was the most significantly phosphorylated protein in GD2+ compared to GD2- cells (S910 and S722). In addition, expression of FAK downstream mediators including Csk, PKCq, PKCl/I, Pyk2, and p38MAPK, was up-regulated in GD2+ compared to GD2- cells. Western blot analysis of FACS sorted SUM159 cells also revealed increased phosphorylation of FAK &gt;80% at Y397 and &gt;25% at Y861 in GD2+ compared to GD2- cells. FAK downstream targets including paxillin, p130 Cas, pERK were also up-regulated in GD2+ cells compared to GD2- cells indicating definitive activation of FAK signaling in GD2+ BCSCs. To investigate the functional role of GD2 in FAK mediated functions, we genetically deleted GD3S using the CRISPR knock-out system in SUM159 cells. only &lt;1% GD2expression compared to &gt;20% in parental cells was observed. GD3S-KO cells grew 5-10% slower in cell culture mostly because of the reduction (15±5%) in adherence. Trans-well assays revealed 3-5 fold reduction in migration and invasion of GD3S-KO compared to parental cells. These data indicate that GD2 and GD3S are not only the markers of BCSCs but also regulators of their function. Finally, we tested the effect of FAK inhibitor (PF-573228) against GD2+ BCSCs and GD3S-KO SUM159 cells. PF-573228 treatment decreased the number of mammospheres generated by GD2+ cells 3-4 fold in a dose dependent manner (100nM-1µm). In addition, treatment of PF-573228, inhibited migration and invasion of GD2+ cells 2 and 3 fold, respectively. However, treatment with PF-573228 on GD3S-KO cells further reduced their ability to migrate and invade by over 70% compared to untreated cells. In addition, GD3S-KO cells failed to form any mammospheres when cultured under low adherence conditions (p&lt;0.00001), whereas the parental cells formed 15-20 mammospheres per 1,000 cells plated. In conclusion, our data demonstrate that FAK signaling is activated in GD2+ cells but that FAK inhibition alone may not be sufficient to inhibit BCSC function. Combined FAK and GD3S inhibition may exert highly synergistic effects against BCSCs.

Citation Format: Nguyen K, Sun JC, Hortobagyi GN, Andreeff M, Battula VL. GD2-mediated FAK signaling regulates breast cancer stem cell function in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-07-03.

Abstract P5-07-02: ST8SIA1 regulates tumorigenesis in triple negative breast cancer

Recurrence in breast cancer is mainly due to metastases and drug resistance in a fraction of primary tumors cells which are also known as cancer stem cells or tumor initiating cells. We found that Ganglioside GD2 identifies breast cancer stem cell (BCSCs) in triple negative breast cancer (TNBC) and that GD2 biosynthesis is tightly regulated by enzyme ST8SIA1 (GD3 synthase) in GD2+ cells. We have reported that ST8SIA1 is highly expressed in TNBC and its expression is highly correlated with p53 mutations primary tumors (Yan et al, SABCS abstract 2016). Here we hypothesize that ST8SIA1 has a functional role in BCSC mediated tumorigenesis in TNBC. To test the hypothesis, we deleted ST8SIA1 in SUM159 cells using CRISPR-Cas9 technology. As expected, deletion of ST8SIA1 in SUM159 cells reduced GD2+ cells from 17±1.5% to 0.3±0.1%. However, cell proliferation assay revealed no significant difference between ST8SIA1-KO and Cas9 control cells. In contrast, in-vitro tumorigenesis by soft-agar assays revealed a complete loss of colony formation in ST8SIA1-KO cells, whereas Cas9 control cells produced 30±10 colonies out of 1000 cells plated. To investigate tumor initiation potential, ST8SIA1-KO- or Cas9 control- SUM159 cells were transplanted in mammary fat pad of NSG mice. Cas9 control cells produced tumors within 1-2 weeks and reached the maximum allowed size by IACUC (1.5cm) within 3-4 weeks. In contrast, ST8SIA1-KO cells failed to produce any tumors even 15 weeks after injections. In addition, survival analysis by log-rank test revealed that most of the cas9 control cell injected mice died within 4 weeks after cell implantation whereas no deaths were observed in ST8SIA1-KO cells injected mice even 100 days after tumor implantation. These data indicate that loss of ST8SIA1 in TNBC cells depletes GD2+ BCSCs and inhibits in-vitro and in-vivo tumorigenesis.

To investigate gene expression changes due to loss of ST8SIA1 in CRISPR knockout cells, we analyzed mRNA expression in ST8SIA1-KO- and Cas9 control- SUM159 cells by RNAseq analysis (done in triplicates for each cell type). At p&lt;0.05 and fold change &gt;2, we found 1502 genes down-regulated and 842 genes up-regulated in ST8SIA1-KO- compared to cas9 control- cells. Ingenuity pathway analysis revealed that several stem cell associated signaling pathway including, wnt, stat3, NFκB, nanog and IL8 whereas tumor suppressor PTEN and p38 MAPK signaling were activated in ST8SIA1-KO- compared to cas9 control- cells. In specific, proteins associated with stem cell function including NOTCH3, PDGFRB, PDGFRA, VCAM1, CXCR4, CXCL12, SOX2, wnt5a were down regulated in ST8SIA1-KO cells whereas DKK1 which acts as an antagonist for wnt-β-catenin signaling, was up-regulated in ST8SIA1-KO cells. These findings were validated by flow cytometry and western blot analysis using specific antibodies. In conclusion, our data suggests that deletion of ST8SIA1 in TNBC cells depletes BCSCs and inhibits tumorigenesis in-vitro and in-vivo. Development of specific inhibitors of ST8SIA1 could be of potential therapeutic value for patients with TNBC.

Citation Format: Battula VL, Nguyen K, Sun JC, Dasgupta A, Bartholomeusz C, Andreeff M. ST8SIA1 regulates tumorigenesis in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-07-02.

Abstract P6-02-01: Metabolic stress induces GD2 expression and cancer stem cell phenotype in triple negative breast cancer

Breast cancer stem cells (BCSCs) have been characterized as a fraction of cells in primary tumors that are drug resistant and have metastatic potential. Ganglioside GD2 has been shown by us and others as a marker for BCSCs. Furthermore, nutrient deprivation associated metabolic stress seen during tumor progression is reportedly associated with the cancer stem cell phenotype. We hypothesized that metabolic stress could induce spontaneous generation of GD2+ BCSCs during tumor progression. To test our hypothesis, we cultured breast cancer cell lines MDA-MB-231 and SUM159 at low seeding density and measured percentage and absolute number of GD2+ cells daily. Flow cytometry analysis revealed that the percentage of GD2+ cells increased from 4.5 ± 2.5 on day 2 to 15 ± 3.8% on day 5 in MDA MB-231 cells and from 8.5 ± 2.8% on day2 to 28 ± 6.2% on day 5 in SUM159 cells (both designated as triple-negative breast cancer, TNBC). To investigate this phenomenon in-vivo, we injected GFP+ MDA-MB-231 cells in NSG mice mammary fat pads and examined GD2 expression in the implanted tumors weekly. Interestingly, we noticed that the percentage of GD2+ also increased from 12 ± 1.5% on week 1 to 30 ± 2.5% on week 6. Next, SUM159 cells were cultured in either nutrient rich (NR, i.e., 10% serum) or nutrient deprived (ND, 1% serum) for 4 days. We found that the percentage of GD2+ cells in NR medium at the end of 4 day culture was ~20% of the total cell population, whereas in ND medium was almost 50%. We then tested the effects of nutrient rich environment on GD2 expression by refreshing the media daily. Interestingly, cells that received fresh media had lower number of GD2+ cells (15 ± 1.5%) compared to cells cultured in the same medium for 4 days (33 ± 2.5%). Our data suggests that nutrient deprivation induces a stem cell phenotype in TNBC cells.

Next, we performed global metabolic profiling (i.e., for a total of 300 biochemical metabolites) using a mass spectroscopy-based approach. We profiled SUM159 cells cultured with NR vs. ND medium (set-1); GD2+ vs GD2- SUM159 cells (set -2); GD2+ vs GD2- MDA-MB-231 cell (set-3). Metabolites associated with amino acid metabolism, in particular glutathione metabolism, including glutamyl-alanine, 5-oxy-proline, proline, glutamine, and glutathione itself were found to be most highly up-regulated in GD2+ compared to GD2- cells and also in cells cultured in serum starved compared to serum rich conditions. Further analysis of these metabolites and their association with GD2+ cell signature raveled that gamma-glutamyl transferase (GGT5), was one of the most highly up-regulated (&gt;150-fold) gene across all the groups. GGT is expressed on cell surface and transfers glutamyl group to amino acids, which then get transported across the membrane. In cancer, cells expressing GGT has been shown to be resistant to chemotherapeutic agents including cisplatin. Targeting glutathione metabolism could be future therapeutic strategy to inhibit BCSC growth in TNBC.

Citation Format: Battula VL, Piyaranthna B, Nguyen K, Sun JC, Jin F, Coarfa C, Nagireddy P, Andreeff M. Metabolic stress induces GD2 expression and cancer stem cell phenotype in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-02-01.

[Mid- to long-term outcomes of cervical disc arthroplasty for symptomatic cervical disc disease: a meta-analysis]

Objective: To compare the benefits and harms of cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion(ACDF) for symptomatic cervical disc disease at mid- to long-term follow-up. Methods: Electronic searches were made in PubMed, EMBASE, and the Cochrane Library for randomized controlled trials with at least 48 moths follow-up.Outcomes were reported as relative risk or standardized mean difference.Meta-analysis was carried out using Revman version 5.3 and Stata version 12.0. Results: Seven trials were included, involving 2 302 participants.The results of this meta-analysis indicated that CDA brought about fewer secondary surgical procedures, lower neck disability index (NDI) scores, lower neck and arm pain scores, greater SF-36 Physical Component Summary (PCS) and Mental Component Summary(MCS) scores, greater range of motion (ROM) at the operative level and less superior adjacent-segment degeneration(P<0.05) than ACDF.CDA was not statistically different from ACDF in inferior adjacent-segment degeneration, neurological success, and adverse events (P>0.05). Conclusions: CDA can significantly reduce the rates of secondary surgical procedures compared with ACDF.Meanwhile, CDA is superior or equivalent to ACDF in other aspects.As some studies without double-blind are included and some potential biases exites, more randomized controlled trials with high quality are required to get more reliable conclusions.

Effects of the balance between type 1 and type 2 T helper cells on ovarian cancer

The balance between type 1 and type 2 T helper cells (the Th1-Th2 balance) is closely correlated with cancer, but the correlation in ovarian cancer remains unconfirmed. We investigated the Th1-Th2 balance for the diagnosis, treatment, and prognostic evaluation of ovarian cancer. Fifty healthy subjects and 50 ovarian cancer patients were recruited. The levels of various cytokines were determined in sera and ovarian cancer tissues using a Th1-Th2 human cytokine array. The usefulness of TNFα, IFNγ, TNFα/IL-4, and IFNγ/IL-4 for ovarian cancer diagnosis was assessed based on receiver operating characteristic (ROC) curves. The relationship between the TNFα/IL-4 level and survival time was investigated based on a survival curve. In the ovarian cancer patients, the levels of Th1 factors (IL-2, IFNγ, TNFα, and IL-13) increased significantly in the sera, and IFNγ and TNFα increased significantly in the ovarian cancer tissues. The levels of Th2 factors (IL-5 and IL-6) increased in the sera, but the level of IL-6 decreased significantly in the ovarian cancer tissues. Serum TNFα/IL-4 and IFNγ/IL-4 levels increased significantly in the peripheral blood of the ovarian cancer patients. ROC curve analysis revealed that TNFα, IFNγ, TNFα/IL-4, and IFNγ/IL-4 levels are useful for ovarian cancer diagnosis, with area under the curve values of 0.831, 0.753, 0.846, and 0.803, respectively. The TNFα/IL-4 level in the ovarian cancer patients was positively correlated with survival time, and the Th1-Th2 balance shifted toward Th1 in the ovarian cancer patients. The TNFα/IL-4 ratio might be useful for the diagnosis and prognosis of ovarian cancer.

High expression of HIF-2α and its anti-radiotherapy effect in lung cancer stem cells

Hypoxia-inducible factor-2 alpha (HIF-2α) has been shown to regulate cell stemness, although the expression and effects of HIF-2α in lung cancer stem cells remained unclear. This study investigated HIF-2α expression in lung cancer stem cells, as well as the relationship between HIF-2α expression and radioresistance in lung cancer cells. Stem-like cells (CD133(+)) in the non-small-cell lung cancer cell line A549 were enriched by serum-free culture conditions, and CD133(+) cells were sorted via fluorescence-activated cell sorting. A549 cells were treated with middle-infrared radiation, and the level of HIF-2α expression was determined by a quantitative polymerase chain reaction assay and western blot analysis. The level of HIF-2α expression in tissue sections from 50 cases of clinically confirmed non-small-cell lung cancer was determined via immunohistochemical analysis, and its correlation with prognosis after radiotherapy was analyzed. HIF-2α levels in CD133(+) cells were significantly higher than those in CD133(-) cells (P = 0.032). However, after radiation treatment, these levels were significantly upregulated in both CD133(+) and CD133(-) cells (P = 0.031 and P = 0.023, respectively). After irradiation, the proportions of apoptotic, dead, and autophagic CD133(+) A549 cells were considerably lower than those of CD133(-) A549 cells (P < 0.05). Furthermore, the recovery of carcinoembryonic antigen to pre-radiation levels was more rapid in lung cancer patients with high levels of HIF-2α expression, and these patients had shorter survival times (P = 0.018). HIF-2α is highly expressed in lung cancer stem cells, which may lead to radioresistance. In conclusion, HIF-2α is a potential prognostic marker for lung cancer.

Associations of depression with impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in Chinese adults

AIM

To examine the association between depression and impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes in middle-aged and elderly Chinese people, and whether depression was associated with different treatment regimens or durations of diabetes.

METHODS

A cross-sectional study was performed among 229,047 adults living in the community aged ≥ 40 years from 25 centres in China. The self-reported depression rating scale Patient Health Questionnaire 9 (PHQ-9) was used to diagnose probable and sub-threshold depression. Glucose metabolism status was determined according to World Health Organization 1999 diagnostic criteria.

RESULTS

The numbers of participants with normal glucose regulation, impaired glucose regulation, newly diagnosed diabetes and previously diagnosed diabetes were 120,458, 59,512, 24,826 and 24,251, respectively. The prevalence of sub-threshold depression in the total sample of participants was 4.8% (4.8%, 4.8%, 4.4% and 5.6% from normal glucose regulation to previously diagnosed diabetes, respectively), and the prevalence of probable depression was 1.1% (1.1%, 1.0%, 0.9% and 1.8% from normal glucose regulation to previously diagnosed diabetes, respectively). Compared with participants with normal glucose regulation, those with previously diagnosed diabetes had increased odds of probable depression [odds ratio (OR) = 1.61, 95% confidence interval (CI) 1.39-1.87] and sub-threshold depression (OR = 1.14, 95% CI 1.06-1.24), after adjustment for multiple confounding factors. Newly diagnosed diabetes or impaired glucose regulation was not associated with depression. Among those with previously diagnosed diabetes, insulin treatment was associated with greater odds of depression compared with no treatment or oral anti-diabetic medicine.

CONCLUSION

Previously diagnosed diabetes, but not newly diagnosed diabetes or impaired glucose regulation, was associated with a higher prevalence of depression. Patients receiving insulin were more likely to have depression than those not receiving treatment or being treated with oral anti-diabetic medicine.

[Ecomorphological explanations of passerines coexistence in alpine meadow]

Species ecomorphological characteristics are the evolutionary results of selective pressures that have enabled individuals of a given species to survive and reproduce. Closely related species co-occurring in homogeneous environments should be morphologically distinct to partition limited resources, so as to minimize interspecific competition. From 1983 to 2012, we studied the ecomorphological characteristics of nine passerine species in alpine meadow. Results showed six ecomorphological characteristics of the nine species were significantly different. Approximately, 92.0% of samples were correctly classified and the correct rates ranged from 84.5% to 100.0%, except for the Oriental Skylark (Eremophila alpestris), which was 79.2%. Accordingly, the nine species were divided into five guilds based on their characteristics. Results indicated that the niches of all species were divergent, and the ecomorphological characteristics of the specific species in each guild were related to their habitats and foraging behaviors. These results also explained the possible mechanisms of different species coexistence in alpine meadow.

MR imaging findings of the intraspinal meningeal melanocytoma: correlation with histopathologic findings

Our aim was to better understand and improve the accuracy of the preoperative diagnosis of intraspinal MM by a combined analysis of MR imaging and pathologic findings. All 5 patients had undergone unenhanced and contrast-enhanced MR imaging examinations. All tumor samples had immunohistochemical reactions to HMB-45, vimentin, S-100, EMA, and Leu-7 antibodies. All 5 cases were located in the intradural extramedullary compartment. Two cases had multifocal lesions, and 3 cases were solitary. Two cases showed homogeneously strong enhancement, and 3 cases showed moderate enhancement on contrast-enhanced T1WI. The tumor cells had positive reactions to HMB-45, vimentin, and S-100 antibodies. MR imaging plays an important role in the detection and diagnosis of intraspinal MM. Final diagnosis should be based on histopathology and IHC examinations.

Uteroplacental insufficiency decreases p53 serine-15 phosphorylation in term IUGR rat lungs

Intrauterine growth restriction (IUGR) increases the incidence of chronic lung disease (CLD). The molecular mechanisms responsible for IUGR-induced acute lung injury that predispose the IUGR infant to CLD are unknown. p53, a transcription factor, plays a pivotal role in determining cellular response to stress by affecting apoptosis, cell cycle regulation, and angiogenesis, processes required for thinning of lung mesenchyme. Because thickened lung mesenchyme is characteristic of CLD, we hypothesized that IUGR-induced changes in lung growth are associated with alterations in p53 expression and/or modification. We induced IUGR through bilateral uterine artery ligation of pregnant rats. Uteroplacental insufficiency significantly decreased serine-15-phosphorylated (serine-15P) p53, an active form of p53, in IUGR rat lung. Moreover, we found that decreased phosphorylation of lung p53 serine-15 localized to thickened distal air space mesenchyme. We also found that IUGR significantly decreased mRNA for targets downstream of p53, specifically, proapoptotic Bax and Apaf, as well as Gadd45, involved in growth arrest, and Tsp-1, involved in angiogenesis. Furthermore, we found that IUGR significantly increased mRNA for Bcl-2, an antiapoptotic gene downregulated by p53. We conclude that in IUGR rats, uteroplacental insufficiency induces decreased lung mesenchymal p53 serine-15P in association with distal lung mesenchymal thickening. We speculate that decreased p53 serine-15P in IUGR rat lungs alters lung phenotype, making the IUGR lung more susceptible to subsequent injury.

Recognition and management of atlanto-occipital dislocation: improving survival from an often fatal condition

OBJECTIVE

To provide an overview of atlanto-occipital dislocation and associated occipital condyle fracturcs so as to alert physicians to this rare injury and potentially improve patient outcome. The pertinent anatomy, mechanism of injury, clinical and radiologic evaluation and the management of these rare injuries are discussed in an attempt to alert physicians to this type of injury and to improve outcome.

DATA SOURCES

The data were obtained from a MEDLINE search of the English literature from 1966 to 1999 and the experience of 4 spine surgeons at a quaternary care acute spinal cord injury unit.

STUDY SELECTION

Detailed anatomic and epidemiologically sound radiology studies were identified and analyzed. Only small retrospective studies or case series were available in the literature.

DATA EXTRACTION

Valid anatomic, biomechanical and radiologic evaluation was extracted from studies. Clinical data came from limited studies and expert opinion.

DATA SYNTHESIS

Early diagnosis is essential and is facilitated by a detailed clinical examination and strict adherence to an imaging algorithm that includes CT and MRI scanning. When the dislocation is identified, timely gentle reduction and prompt stabilization throuigh nonoperative or operative means is found to optimize patient outcome.

CONCLUSIONS

Atlanto-occipital dislocation should be suspected in any patient involved in a high speed motor vehicle or pedestrian collision. Once suspected, proper imaging and appropriate management of these once fatal injuries can improve survival and neurologic outcome.

Hereditary familial vestibular degenerative diseases

Identification of genes involved in hereditary vestibular disease is growing at a remarkable pace. Mutant mouse technology can be an important tool for understanding the biological mechanism of human vestibular diseases.

Origin of vestibular dysfunction in Usher syndrome type 1B

It is still debated to what extent the vestibular deficits in Usher patients are due to either central vestibulocerebellar or peripheral vestibular problems. Here, we determined the origin of the vestibular symptoms in Usher 1B patients by subjecting them to compensatory eye movement tests and by investigating the shaker-1 mouse model, which is known to have the same mutation in the myosin-VIIa gene as Usher 1B patients. We show that myosin-VIIa is not expressed in the human or mouse cerebellum and that the vestibulocerebellum of both Usher 1B patients and shaker-1 mice is functionally intact in that the gain and phase values of their optokinetic reflex are normal. In addition, Usher 1B patients and shaker-1 mice do not show an angular vestibuloocular reflex even though eye movement responses evoked by electrical stimulation of the vestibular nerve appear intact. Finally, we show histological abnormalities in the vestibular hair cells of shaker-1 mice at the ultrastructural level, while the distribution of the primary vestibular afferents and the vestibular brainstem circuitries are unaffected. We conclude that the vestibular dysfunction of Usher 1B patients and shaker-1 mice is peripheral in origin.

Traumatically induced lymphangioma of the ulnar nerve. Case report

Lymphangiomas, benign hamartomatous lesions involving lymphatic tissue, result from a failure of lymphatic channels to communicate with the venous system or normal lymphatic channels. The authors describe a case in which a lymphangioma arising within the ulnar nerve developed after trauma to the same area. This is the second reported case of a lymphangioma that originated from a peripheral nerve and the first case in which the lesion was associated with trauma. The authors propose that a lymphangioma involving the peripheral nerve may be the result of trauma.

Cervical myelocystoceles and meningoceles: long-term follow-up

Little is known about the long-term prognosis of patients with cervical myelocystoceles and meningoceles. In this study, we report the long-term follow-up (average 10 years and 8 months) of 8 patients with cervical myelocystoceles and meningoceles. Neurologic, orthopedic, urologic and psychosocial status was assessed on long-term follow-up. The results indicate that in patients with cervical myelocystoceles, neurologic deficits become noticeable in the first year of life as the infant matures. Motor deficit was common in these patients, whereas sensory and urologic deficits did not occur. We believe that this is related to underlying myelodysplasia. In addition, patients with cervical myelocystoceles tend to have significant orthopedic problems. In contrast, patients with cervical meningoceles do not have neurologic deficits, but do develop mild orthopedic problems.

Post-exposure chemoprophylaxis (PECP) against SIV infection of macaques as a model for protection from HIV infection

We report that simian immunodeficiency virus (SIV) infection in macaques is a valuable animal model for studying post-exposure chemoprophylaxis (PECP). PECP with the acyclic nucleoside reverse transcriptase inhibitors 9-(2-phosphonylmetho-xyethyl)adenine (PMEA) and (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA) at early viral infection can provide long-term protection against subsequent heterologous SIV challenge. Eight macaques previously treated with PECP (called PECP macaques) and four naive controls were challenged intravenously with the most virulent form of SIV, SIV(PBj14). All controls showed signs of SIV(PBj14)-induced acute disease syndrome on days 6 and 7 post-inoculation (PI). One had a fatal viral infection and two surviving controls had persistent infection and decreased CD4+ cell count. Virologic studies of the three surviving controls revealed SIV in multiple lymphoid tissues and peripheral blood mononuclear cells (PBMCs) at necropsy. In contrast, the PECP macaques showed none to mild signs of acute disease syndrome at day 9 PI and exhibited only transient SIV infection in PBMCs between weeks 1 and 8 PI. In virologic studies of five PECP macaques necropsied, two macaques were SIV-negative and the other three were SIV-positive only in either lymph node or bone marrow. Three SIV(PBj14)-challenged PECP macaques, that were randomly reserved for a follow-up study for > 4.0 years PI showed extremely low to undetectable levels of PBMC-associated viremia and normal to increased levels of CD4 + and CD8 + cell counts throughout the study. Our results indicate that early PECP could activate immune responses to protect against subsequent infection with heterologous challenge virus.

Spontaneous resolution and recurrence of a Chiari I malformation and associated syringomyelia. Case report

The spontaneous resolution of syringomyelia has been reported infrequently. In patients with Chiari I malformations, resolution of the syringomyelia has sometimes been associated with improvement of their malformation. The authors present a case of spontaneous resolution followed by recurrence of syringomyelia and a corresponding change in the Chiari malformation. This case is of interest in light of the theories postulated to explain spontaneous resolution of syringomyelia.

Hemorrhagic moyamoya disease during pregnancy

BACKGROUND

Intracranial hemorrhage in pregnant patients with Moyamoya disease is rare. We review the case of one such patient who presented with pre-eclampsia and a catastrophic intracerebral hemorrhage in order to highlight the associated management difficulties.

METHODS

A case of a pregnant (31 weeks) female brought to the emergency department with hypertension and a progressive decrease in her level of consciousness is presented. She rapidly developed a dilated right pupil and left extensor posturing. A CT scan of her head showed a large putamenal intracerebral hemorrhage. She was intubated, ventilated and given intravenous mannitol and magnesium sulfate. She underwent a simultaneous craniotomy and Cesarean section. Post-operatively the patient's ICP and jugular venous saturation were monitored in the intensive care unit.

RESULTS

The patient delivered a 1185 g infant who did well. The patient's ICP was well controlled until the tenth post-operative day when she developed malignant brain edema and died.

CONCLUSION

This case highlights three important points. First, simultaneous craniotomy and Cesarean section can be performed. Second, intraoperative control of bleeding Moyamoya vessels is described. Third, the difficult post-operative management of these cases is highlighted. The literature regarding Moyamoya disease and pregnancy is reviewed and some recommendations for the management of this rare but potentially deadly condition are presented.

Effect of speech processor program modifications on cochlear implant recipients' threshold and maximum acceptable loudness levels

This study's purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients' thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants' threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Optimization of speech processor fitting strategies for Chinese-speaking cochlear implantees

OBJECTIVES

To compare speech recognition performance in Chinese-speaking cochlear implant patients with a speech processor program selected by the clinical audiologist in Taiwan and with a new speech processor program based on the Washington University clinical procedure developed by Skinner et al.

STUDY DESIGN

Six adult Chinese-speaking patients implanted with the Nucleus cochlear implant system participated in this study.

METHODS

A fitting procedure developed in 1995 by Skinner et al. at Washington University School of Medicine was used to create a new speech processor program to optimize each patient's hearing in everyday life. Speech tests (vowels, consonants, tones, and words), sound-field thresholds, and a self-report questionnaire were used to evaluate each patient's performance with his or her previous speech processor program and a new one.

RESULTS

Four of the six patients had significant changes from the previous to the new speech processor program. These changes were associated with improvement in score on at least one speech test, more sensitive sound field thresholds, and reported improvement in some everyday listening situations on the questionnaire.

CONCLUSIONS

These results suggest that use of this procedure with adult cochlear implantees may improve benefit in everyday life. Analysis of the speech test stimuli and patients' responses provides a basis for modification or creation of new Mandarin Chinese speech tests for preoperative and postoperative evaluation of adult cochlear implant patients.

Marginal leakage of amalgam restorations pretreated with various liners

PURPOSE

To evaluate and compare the microleakage of amalgam restorations lined with four different liners.

MATERIALS AND METHODS

Cylindrical occlusal cavities were prepared in extracted human molars and the teeth were then divided into four groups and lined with one of four liners: Amalcoden, AM (glass-metal ionomer), FujiDuet, FD (glass ionomer), Amalgambond, AB (adhesive resin), or copal varnish, CV. Each cavity was then restored with a high-copper amalgam alloy and aged for 7 days in 37 degrees C distilled water. The specimens were then thermocycled for 300 cycles followed by immersion in 0.5% basic fuchsin dye solution for 24 hours. The teeth were then embedded in resin, sectioned, and dye penetration at the tooth/amalgam interface evaluated microscopically at x 100 and scored from 0 to 4 (0 = no leakage and 4 = greatest leakage).

RESULTS

The median values were: AM = 1.0; FD = 0.5; AB = 1.1; and CV = 4.0. Statistical analysis using Kruskal-Wallis and Mann-Whitney U indicated no significant differences between AM and AB or FD and AB. CV was however, significantly worse at P < 0.01.

Tibial mononeuropathy from a lower limb synovial cyst

BACKGROUND

Tibial mononeuropathy due to compression by a synovial cyst is uncommon with fewer than 10 cases reported in the literature.

METHOD

Case Study.

RESULTS

Tibial motor mononeuropathy with focal conduction block between the popliteal fossa and ankle was identified by electrophysiological testing. Magnetic resonance imaging and surgical exploration identified a synovial cyst compressing the nerve just distal to the popliteal fossa.

CONCLUSIONS

The combination of electrophysiological localization and imaging in cases of unexplained tibial mononeuropathy may identify an unexpected structural cause.

Is the older ear more susceptible to noise damage?

Eight chinchillas aged 8.9 to 12.8 years were used to examine the effect of noise on the aging ear. The left malleus/incus complex was removed to produce a 50-dB conductive hearing loss which protected those ears from noise damage. The animals were then exposed for 36 days to an octave band of noise with a center frequency of 0.5 kHz and a sound pressure level of 95 dB. After 1 hour (n = 2) or 1 month (n = 6) of recovery, their cochleas were prepared for microscopic examination. The percentages of missing inner hair cells (IHCs) were 7.4 +/- 6.0% and 7.8 +/- 5.1% for their protected and exposed ears, respectively. Outer hair cell (OHC) loss was 12.8 +/- 8.7% and 20.6 +/- 7.8% for their protected and exposed ears, respectively. A paired sample Student's t test revealed that OHC loss was significantly greater (P = .003) in the older-exposed compared to the older-protected ears whereas IHC loss was not significantly different. For younger-exposed ears (i.e., 1 to 3 years), the percentages of missing IHCs and OHCs averaged 2.6 +/- 2.0% and 12.3 +/- 4.6%, respectively. When the aging-related cell loss was subtracted from total loss in the younger- and older-exposed ears, the noise-induced loss of sensory cells in the older ears was not significantly different from that in the younger ears. Therefore, it is concluded that older chinchilla ears are not more susceptible to noise damage than younger ears.

Shivering thermogenesis during acute hypercapnia

The effects of acute hypercapnia on human thermoregulation during cold exposure were investigated by immersion of eight male subjects to the neck in a 15 degrees C water bath until their core temperatures dropped to 35 degrees C or until 1 h of immersion had elapsed. Air was inspired throughout each experiment, with the exception of a 15-min period commencing with the attainment of an esophageal temperature (Tes) of 36.5 degrees C, during which subjects inspired a gas mixture containing 4% CO2, 20% O2, and 76% N2. Oxygen uptake (VO2, L.min-1), inspired minute ventilation (Vi, L.min-1), esophageal temperature (Tes, degrees C), rectal temperature (Tre, degrees C), mean unweighted skin temperature (Tsk, degrees C), mean heat flux (Q, W.m-2), and electromyographic activity (EMG, mV) of the trapezius and masseter muscles were recorded continuously. VO2 and integrated EMG activity (IEMG) were used as the primary indicators of shivering thermogenesis. Shivering EMG was attenuated immediately following the switch of the inhaled gas mixture from air to 4% CO2. For both the masseter and trapezius muscles the IEMG was significantly suppressed (p < 0.05) during the hypercapnic period. The IEMG values preceding the switch to the hypercapnic mixture were 15% greater than those during the CO2 period. Similarly, IEMG values in the post-CO2 period were 55% greater than during the CO2 period. It is concluded that acute periods of hypercapnia during cold exposure may result in transient suppression of shivering tremor, but this does not appear to affect thermal balance, as reflected in the absence of any significant effect on Tes.

Effects of blood-volume distribution on the characteristics of the carotid baroreflex in humans at rest and during exercise

Seven supine subjects were studied at rest and during mild to moderate dynamic leg exercise with and without unloading of the cardiopulmonary baroreceptors accomplished by exposing the lower portion of the body to a subatmospheric pressure of 20 mmHg (Lower Body Negative Pressure, LBNP). The function of the cardiac branch of the carotid baroreflex was studied over its full operational range by measuring R-R intervals during application of pulse synchronous graded pressures (40 to -65 mmHg) in a neck-chamber device. Raising the carotid transmural pressure (systolic arterial pressure minus neck-chamber pressure) induced increasing R-R intervals in all conditions. In conformity with previous results from our laboratories it was found that the maximal rate of change in relative R-R intervals and the corresponding transmural pressure were higher during exercise than at rest, indicating that exercise increased the carotid baroreflex sensitivity and shifted its optimal buffering range to higher arterial pressures. LBNP did not affect the characteristics of the reflex at rest nor during exercise. It is concluded that reduced central venous pressure with consequent selective cardiopulmonary receptor disengagement exerts no influence on the carotid baroreflex control of heart rate (HR), as tested over the entire arterial pressure-effector response relation, either at rest or during mild-moderate exercise.

Autonomic nervous control of heart rate during blood-flow restricted exercise in man

Power spectra of instantaneous heart rate (fc) allows the estimation of the contribution of sympathetic and parasympathetic control of fc during steady-state conditions. The present study was designed to examine autonomic control of fc as influenced by normal dynamic leg exercise and by ischemic leg exercise. Eight subjects performed supine cycle ergometry at 30% of their control peak work rate, with and without blood-flow restriction. Blood-flow restriction was induced by exposing the exercising legs to a supra-atmospheric pressure of 6.7 kPa (leg positive pressure; LPP). The exercise responses of arterial pressure and fc increased (P < 0.05) by LPP exposure. The exaggerated pressor response may be attributed to a chemoreflex drive originating in the ischemic muscles. Exposure to LPP during exercise also produced a significant decrease in parasympathetically mediated high frequency (HF; 0.15-1.00 Hz) fluctuation of fc, as indicated by a decrease (P < 0.05) in percent HF power compared to the control exercise level. During LPP exercise, the sympathetically mediated very low frequency (VLF; 0-0.05 Hz) fluctuation of fc increased, as indicated by an increase (P < 0.05) in percent VLF power above control exercise levels. Both LPP and control exercise conditions decreased (P < 0.05) power in all frequency ranges of interest compared to their respective resting conditions. The results suggest that the increase in fc associated with normal dynamic exercise was mediated predominantly by parasympathetic withdrawal, whereas the exaggerated fc response during ischemic exercise resulted from a combination of cardiac sympathetic drive and parasympathetic withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging modalities of craniosynostosis with surgical and pathological correlation

Premature fusion of the sutures of the skull has been extensively analyzed and several diagnostic imaging modalities have been proposed. Radiographic, scintigraphic and computed tomographic features of craniosynostosis have been reported. This study was initiated (a) to determine the value and accuracy of plain skull radiography, skull scintigraphy and cranial CT; and (b) to determine the optimal imaging modality for the evaluation of a clinically suspected craniosynostosis. The study is based on 36 patients with clinical suspicion of craniosynostosis who underwent craniectomy and cranioplasty. One hundred and three sutures were pathologically and/or surgically evaluated. The overall accuracy rate for skull radiography was 89%, skull scintigraphy, 66%, and cranial CT, 94%. Routine skull series are adequate in the majority of cases of craniosynostosis. Skull scintigraphy is less accurate, more costly, and has a limited role in the evaluation of craniosynostosis. Cranial CT should be reserved for those cases in which the findings in the routine skull series are not clearly positive or negative, or in cases of more complex craniofacial anomalies.