Squamous cell carcinoma of the cystic duct: A case report and literature review

RATIONALE

Pure squamous cell carcinoma (SCC) of the gallbladder is a rare malignant biliary tract tumor predominantly found in the body and neck of the gallbladder. However, its occurrence in the cystic duct is even rarer. Given its rarity, no established guidelines or consensus currently exist regarding the treatment of pure SCC of the gallbladder. We report an unusual case of SCC originating from the cystic duct with the intent of providing insights into the therapeutic approach for this type of malignancy.

PATIENT CONCERNS

A male patient presented to our hospital with acute cholecystitis. Unexpectedly, imaging revealed gallbladder malignancy.

DIAGNOSES

Pathologic examination after surgery confirmed SCC of the cystic duct.

INTERVENTIONS

Despite elevated bilirubin levels, we were able to exclude hilar involvement, enabling radical tumor resection. Intraoperatively, we discovered that the tumor was located in the cystic duct, a site associated with a high likelihood of invasion into neighboring organs. The tumor demonstrated a predominantly exophytic growth pattern, which prompted us to refrain from extending the resection range, thereby striking a balance between complete tumor removal and surgical trauma. We performed liver wedge resection only to ensure a negative resection margin while preserving the anatomical structure to the greatest extent possible. Postoperative recovery was rapid and uncomplicated. Pathological examination confirmed pure SCC, which led us to initiate a regimen of nab-paclitaxel and cisplatin, which is known to be effective in other organ SCCs. Remarkably, the patient experienced a rare and severe posttreatment cardiovascular event. Consequently, we switched the patient to a chemotherapy regimen of gemcitabine and cisplatin, which ultimately yielded positive clinical outcomes.

OUTCOMES

no evidence of tumor recurrence was observed within 1 year after surgery.

LESSONS

The diagnosis and therapeutic strategy for rare tumors such as gallbladder SCC should be meticulously tailored based on their unique characteristics to optimize postoperative patient outcomes.

[Clinicopathological features of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma]

Objective: To investigate the clinicopathological features, immunophenotype and gene alterations of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA). Methods: Fifteen case of TL-LGNPPA diagnosed at Zhejiang Cancer Hospital (5 cases) and the First Affiliated Hospital, Zhejiang University School of Medicine (10 cases) from November 2011 to August 2020 were collected. Clinical and pathological examinations, immunohistochemical staining and next-generation sequencing were performed. The clinicopathological and molecular characteristics were summarized, and relevant literature was reviewed. Results: Fifteen patients were identified and included. Their median age was 36 years (range, 20-60 years). The male-female ratio was 1.0∶1.1. The most common symptoms were epistaxis and nasal obstruction. The neoplasms were located on the roof of the nasopharynx or the posterior margin of the nasal septum. The pathological features included complex papillary and glandular structures mainly composed of single or pseudostratified cubic and columnar cells, with mild to moderate cytological atypia. In some cases, spindle cell features, nuclear grooves, ground glass nuclei, squamous metaplasia, or scattered psammoma bodies were identified. In addition, nuclear polar reversal cells, hobnail cells and micropapillary structures were found, but have not been reported in previous literature. Immunohistochemistry showed that the tumor cells were diffusely positive for TTF1, CK7, vimentin and CKpan; focally positive for p40, CK5/6 and p16; and negative for Tg, NapsinA, CK20, CDX2, S-100 and PAX8. The Ki-67 positive rates ranged from 1% to 20% and were≤10% in thirteen cases (13/15). EBER in situ hybridization was negative in all cases. DNA sequencing of 6 specimens was performed and all specimens were found harboring gene mutations (EWSR1, SMAD2, ROS1, JAK3, GRIN2A, ERRCC5, STAT3, and TET2), but no hot spot gene alterations were found. No MSI-H and MMR related gene changes were detected. All tumors showed low tumor mutation burden. All 15 patients underwent endoscopic surgery, and only 1 of them underwent radiotherapy postoperatively. All patients were recurrence free and alive at the end of follow-up periods (range: 23 to 129 months). Conclusions: TL-LGNPPA is a rare indolent tumor of the nasopharynx and exhibits a unique morphology and immunophenotype. Endoscopic resection is an effective treatment for TL-LGNPPA with excellent overall prognosis.

TRIM5α recruits HDAC1 to p50 and Sp1 and promotes H3K9 deacetylation at the HIV-1 LTR

Tripartite motif-containing protein 5α (TRIM5α) is generally known to block the postentry events of HIV-1. Here, we report an uncharacterized role for TRIM5α in the maintenance of viral latency. Knockdown of TRIM5α potentiates the transcription of HIV-1 in multiple latency models, which is reversed by shRNA-resistant TRIM5α. TRIM5α suppresses TNFα-activated HIV-1 LTR-driven as well as NF-κB- and Sp1-driven gene expression, with the RING and B-box 2 domains being the essential determinants. Mechanistically, TRIM5α binds to and enhances the recruitment of histone deacetylase 1 (HDAC1) to NF-κB p50 and Sp1. ChIP‒qPCR analyses further reveal that the association of TRIM5α with HIV-1 LTR induces HDAC1 recruitment and local H3K9 deacetylation. Conserved suppression effects of TRIM5α orthologs from multiple species on both HIV-1 and endo-retroelement HERV-K LTR activities have also been demonstrated. These findings provide new insights into the molecular mechanisms by which proviral latency is initially established and activatable proviruses are resilenced by histone deacetylase recruitment.

[Clinical features and prognoses of re-operated patients for persistent/recurrent papillary thyroid carcinoma]

Objective: To investigate the clinicopathological characteristics and the survival of re-operated patients for persistent/recurrent papillary thyroid carcinoma (PTC) and risk factors for re-recurrence after the second operation. Method: A retrospective analysis of 69 cases underwent re-operation for persistent/recurrent PTC in Sichuan Cancer Hospital from January 2010 to December 2016 was performed. There were 21 males and 48 females, aged 14-85 (44.8) years old. According to the imaging after initial treatment, they were divided into a recurrence group (42 cases) and a persistent disease/residual group (27 cases). The positive rates of ipsilateral paratracheal lymph node metastases at re-operation were calculated and compared by chi-square test. Patients were divided into different subgroups according to potential risk factors for re-recurrence. Kaplan-Meier (K-M) method was used for survival analysis. Results: The positive rate of ipsilateral paratracheal lymph node metastasis in recurrence group (15/42, 35.7%) was significantly lower than that in the persistent disease/residual group (17/27, 63.0%) (χ²=4.91, P<0.05). The follow-up period after re-operation was 60-104 months, with a median of 66 months, and 8 patients were lost to follow-up. Permanent hypoparathyroidism occurred in 2 cases (2.9%) and permanent recurrent laryngeal nerve palsy in 1 case (1.4%). Twenty patients had structural recurrences and/or distant metastases. The 5-year disease-specific survival rate was 92.8% and the 5-year recurrence-free survival rate was 68.1%. Survival analysis was performed on risk factors such as age≥55 years old, recurrent tumor diameter ≥4 cm, number of positive lymph nodes ≥ 10, and obvious extracapsular invasion (ENE). Among them, age and diameter of recurrent tumor had significant influences on recurrence-free survival rate (χ² was 6.36, 8.17, respectively, both P values<0.05). There was a statistically significant difference in recurrence-free survival rates between ENE(+) group and ENE(-) group (χ²=5.52, P<0.05). Conclusion: For the re-operated patients due to persistence/ recurrence PTC, attention should be paid to protecting the parathyroid gland and recurrent laryngeal nerve during re-operation. Timely and effective postoperative follow-up for patients aged ≥ 55 years, with recurrent tumor diameter ≥ 4 cm and ENE(+), can significantly improve their prognoses.

[Comparison of three kinds of free flaps used in patients with oral and oropharyngeal tumors]

Objective: To compare the recovery and quality of life of patients with oral and oropharyngeal tumors treated with three kinds of free soft tissue flaps. Methods: The clinical data of 103 patients, including 66 males and 37 females, aged 26-74 years, who underwent primary repair of defects after resection of oral and oropharyngeal tumors in Sichuan Tumor Hospital from July 2014 to August 2020 were analyzed. Anterolateral thigh flap (ALTF) was used in 43 patients, radial forearm free flap (RFFF) in 45 patients, and lateral arm free flap (LAFF) in 15 patients. Postoperative qualities of life of patients were evaluated by the university of Washington quality of life questionnaire and oral health impact scale (HIP-14 Chinese edition). SPSS 23.0 software was used for statistical analysis. Results: The T staging of RFFF or LAFF group was significantly lower than that of ALTF group (P<0.05). There was no significant difference in mean flap areas between ALTF group ((55.87±27.38) cm²) and LAFF group ((49.93±19.44) cm²), while RFFF group had smaller mean flap area ((33.18±6.05) cm²) than ALTF group (t=5.311, P<0.001) and LAFF group (t=3.284, P=0.005). In terms of oral functions including swallowing, mastication, taste and spitmouth, there were no significant differences between LAFF group and RFFF group (P>0.05), but both groups had better oral functions than ALTF group (P<0.05). There was no significant difference in appearance scores between LAFF group (75(75, 75)) and ALTF group (75(75,75) vs.75(75,75),Z=-1.532, P=0.126), and both groups had higher scores than RFFF group (50(50, 75),Z values were -3.447 and -3.005 respectively, P<0.05). RFFF group had higher speech score (100(67, 100)) than LAFF group (67(50, 76),Z=-2.480, P<0.05) and ALTF group (67(33, 67),Z=-5.414, P<0.05). ALTF group had lower mean score of quality of life than RFFF group [72(56,77) vs.79(69, 89),Z=-3.070, P<0.05), but there was no statistical difference in the mean scores of qualities of life between ALTF group and LAFF group (Z=1.754, P=0.079). According to the evaluation of oral health impact scale (HIP-14 Chinese version) 1 year after surgery, individual item scores and the average score of all items in ALTF group were lower than those in RFFF and LAFF groups (P<0.05), with no significant difference between RFFF group and LAFF group (P>0.05). Conclusions: RFFF has unique advantages for small tissue defects, while ALTF is suitable for large tissue defects, such as buccal penetrating defect, whole tongue and near whole tongue defect, and LAFF is a compromise choice between ALTF and RFFF. ALTF is inferior to RFFF and LAFF in oral functional reconstruction, including swallowing, chewing, taste and spittle. ALTF and LAFF are superior to RFFF in postoperative appearance.

Successful totally laparoscopic right trihepatectomy following conversion therapy for hepatocellular carcinoma: A case report

BACKGROUND

About 20%-30% of newly diagnosed hepatocellular carcinoma (HCC) patients are surgically feasible due to a variety of reasons. Active conversion therapy may provide opportunities of surgery for these patients. Nevertheless, the choice of surgical procedure is controversial after successful conversion therapy. We report a patient with HCC who underwent successful laparoscopic right trisectionectomy after conversion therapy with portal vein embolization and transarterial chemoembolization.

CASE SUMMARY

A 67-year-old male patient presented to our hospital with epigastric distention/ discomfort and nausea/vomiting for more than 1 mo. Contrast-enhanced computed tomography scan of the abdomen demonstrated multiple tumors (the largest was ≥ 10 cm in diameter) located in the right liver and left medial lobe, and the left lateral lobe was normal. The future remnant liver (FRL) of the left lateral lobe accounted for only 18% of total liver volume after virtual resection on the three-dimensional liver model. Conversion therapy was adopted after orally administered entecavir for antiviral treatment. First, the right portal vein was embolized. Then tumor embolization was performed via the variant hepatic arteries. After 3 wk, the FRL of the left lateral lobe accounted for nearly 30% of the total liver volume. Totally laparoscopic right trisectionectomy was performed under combined epidural and general anesthesia. The in situ resection was performed via an anterior approach. The operating time was 240 min. No clamping was required during the surgery, and the intraoperative blood loss was 300 mL. There were no postoperative complications such as bile leakage, and the incision healed well. The patient was discharged on the 8^th postoperative day. During the 3-mo follow-up, there was no recurrence and obvious hyperplasia of residual liver was observed. Alpha-fetoprotein decreased significantly and tended to be normal.

CONCLUSION

Due to the different biological characteristics of the liver cancer and the pathophysiological features of the liver from other organs, the conversion treatment should take into account both the feasibility of tumor downstaging and the volume and function of the remnant liver. Our case provides a reference for clinicians in terms of both conversion therapy and laparoscopic right trisectionectomy.

[Posterior sternocleidomastoid border approach of gasless transaxillary endoscopic thyroidectomy in patients with papillary thyroid carcinoma: comparison with sternocleidomastoid fascia approach]

Objective: To examine the posterior sternocleidomastoid border approach which elevated whole sternocleidomastoid in gasless transaxillary endoscopic thyroidectomy. Methods: The clinical data of 46 patients with papillary thyroid carcinoma treated with gasless transaxillary endoscopic thyroidectomy from May 2019 to June 2020 at Department of Head and Neck Surgery, Sichuan Cancer Hospital was analyzed retrospectively. There were 9 males and 37 females, aged (38.6±12.0) years (range: 19 to 74 years). Fourteen and 32 cases performed posterior sternocleidomastoid border and sternocleidomastoid fascia approach, respectively. Comparative analysis were performed on clinical characters, surgical outcomes, postoperative complications, postoperative pain score, and quality-of-life of postoperative 1 month by t test, Wilcoxon rank sum test, Fisher exact test and χ2 test,respectively. Resuts Complete exposure of central compartment was higher (11/14 vs. 34.4%(11/32),χ²=7.624, P=0.006), more lymph nodes was retrieved (4.2±2.9 vs. 2.0±2.5, t=2.663, P=0.011) in posterior sternocleidomastoid border approach. There were no significant differences between groups in postoperative complications such as recurrent laryngeal nerve palsy (1/14 vs. 3.1%(1/32), P=0.521) and transient hypoparathyroidism (0 vs. 6.2%(2/32), P=1) and pains and quality-of-life. Conclusion: Posterior sternocleidomastoid border approach of gasless transaxillary endoscopic thyroidectomy is safe and reliable and has the advantage of central compartment dissection without increasing trauma.

LINC00346 promotes hepatocellular carcinoma progression via activating the JAK-STAT3 signaling pathway

Hepatocellular carcinoma (HCC) remains the most common malignant tumor worldwide. Long noncoding RNAs can modulate various tumorigenic processes. In addition, growing evidence has indicated tha the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is activated in multiple cancers, including HCC. Recently, it was found that LINC00346 can participate in several cancers. Nevertheless, the biological roles of LINC00346 in HCC have been barely investigated. In this study, the function of LINC00346 was specifically concentrated upon. We observed that LINC00346 was obviously elevated in HCC cells (Bel7404, Huh-6, HepG2, and QGY-7703 cells). Then, Bel7404 and HepG2 cells were overexpressed with LINC00346. Overexpression of LINC00346 repressed HCC cell survival and cell proliferation. In addition, apoptosis of Bel7404 and HepG2 cells was triggered by LINC00346 upregulation. Bel7404 and HepG2 cell cycle was arrested in the G1 phase by LINC00346. Meanwhile, we conducted wound-healing assay and Transwell invasion assays. As shown, we observed that the migratory and invasive capacities of Bel7404 and HepG2 cells were remarkably restrained by the increase of LINC00346. Moreover, we showed that LINC00346 overexpression activated the JAK-STAT3 pathway, which is involved in many cancers. Afterward, in vivo experiments were utilized and we proved that LINC00346 was able to induce HCC tumor growth via activating the JAK-STAT3 pathway. To conclude, we revealed the potential possibility of developing LINC00346 as an indicator for HCC.

[Progress in research of thyroid carcinoma related gene mutation and epigenetics]

Thyroid cancer is one of the most common endocrine malignant tumors, and its molecular pathogenesis is also a process of multiple genes involved in many steps of carcinogenesis. With the development of molecular biology technology, a variety of related gene mutations and epigenetic phenomena have been found in thyroid cancer tissues. It is helpful to understand the latest progress in the research of the gene mutation and epigenetics of thyroid cancer for its early diagnosis, prevention and the development of targeted drugs.

[Clinicopathological characteristics of papillary thyroid microcarcinoma and risk factors for central lymph node metastasis]

Objective: To analyze the clinicopathological characteristics of papillary thyroid microcarcinoma (PTMC) and risk factors for central lymph node metastasis(CLNM) in PTMC. Methods: The data of 900 patients with PTMC initially treated in our hospital from January 2004 to December 2015 were retrospectively analyzed. Chi-square test and Logistic regression analysis were performed to determine the risk factors for CLNM. Results: CLNM affected 162 (22.9%) of 707 patients treated with central lymph node dissection. Age, maximum tumor size, multifocality, bilaterality, and extracapsular spread (ECS) were significantly correlated with CLNM (all P<0.01). Age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread were independently correlated with CLNM. Conclusion: A prophylactic central lymph node dissection should be considered in PTMC patients with age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread.

Self-reported Sleep Improvement in Buprenorphine MAT (Medication Assisted Treatment) Population

This is a prospective, naturalistic study to evaluate patient's report on sleep and depression in early recovery while receiving buprenorphine in Medication Assisted Treatment (MAT). 40 Subjects entering into MAT with buprenorphine/naloxonefor opioid dependence disorder were recruited. No change of concurrent treatment was made. Subjects were administered Sleep Scale from the Medical Outcomes Study (MOS-Sleep), a 5-item Supplemental Sleep Scale (SSS), and the Beck Depression Inventory II (BDI-II). The measures were administered at day 0 (baseline), 30, 60 and 90 days. The result showed that patients reported significant progressive improvements in three MOS-Sleep subscales: sleep disturbance, sleep indices I and II. The mean scores of SLPD4 (Sleep disturbance) at day 0, 30, 60, 90 were 62.4, 53.2, 53.3, and 48.4 respectively (p=0.0029). Similarly, subscores of SLP6 (Sleep Problem Index I) and SLP 9 (Sleep Problem Index II) were also significantly decreased over time (P=0.038 for SLP6 and p=0.007 for SLP9). BDI-II depression scores improved from "Moderate depression" at baseline to "Mild depression". The mean BDI score decreased from 24.2 to 17.0 after 90 days of treatment. Findings suggest that subjects reported improvement in both sleep and depression after initiating MAT with buprenorphine/naloxone.

Experimentally simulating quantum walks with self-collimated light

In self-collimated photonic crystal, periodically arranged air holes of sub-wavelength scale provide flattened equi-frequency curves perpendicular to the ΓM direction, which allow light or photons propagating in a quasi-uniform medium without diffraction. Here we for the first time experimentally simulate four-step single-photon discrete time quantum walks with classical light in such a photonic crystal chip fabricated on silicon-on-insulator. Similarities between theoretical expectations and experimental results are higher than 0.98. The functional area is compact and can be extended to construct more complicated linear quantum circuits.

[Expression and significance of toll-like receptors 7 and 8 in brain and lung tissues of death cases caused by EV71 infection]

OBJECTIVE

To study the significance of toll-like receptors (TLR) -7 and -8 in the pathogenesis of infection caused by Enterovirus type 71 (EV71) through measuring the expression of TLR7 and TLR8 in brain and lung tissues from the death cases caused by EV71 infection.

METHODS

Nine children who died of EV71 infection (EV71 group) were selected as study subjects, and 7 children who died of accidents or non-infectious diseases were used as the control group. Brain and lung tissues from the death cases in both groups at autopsy were collected, and immunohistochemistry was applied to detect the expression of TLR7 and TLR8 in lung and brain tissues in both groups. Integrated optical density (IOD) was applied for semi-quantitative analysis of the expression of TLR7 and TLR8.

RESULTS

Immunohistochemical results showed that the expression of TLR7 and TLR8 in lung and brain tissues was strongly positive in the EV71 group, and the IOD values in the EV71 group were also significantly higher than those in the control group (P<0.05). There was no significant difference in the expression of TLR7 and TLR8 between lung and brain tissues in the EV71 group (P>0.05).

CONCLUSIONS

TLR7 and TLR8 are highly expressed in lung and brain tissues from the patients who die of severe EV71 infection, suggesting that TLR7 and TLR8 may be involved in the pathogenesis of brain and lung damages caused by severe EV71 infection.

Conservation and population genetic diversity of Curcuma wenyujin (Zingiberaceae), a multifunctional medicinal herb

Curcuma wenyujin is an important multifunctional medicinal herb in China. Currently, populations of C. wenyujin are decreasing, and wild individuals have almost disappeared from their natural habitats. Moreover, little is known regarding the molecular characteristics of this plant. In this study, we investigated the genetic diversity and variation of five populations of C. wenyujin, using ran-dom amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. We found that the percentages of polymorphic loci (PPL) at the species level (98.25% by RAPD and 100% by ISSR) were significantly higher than those at the population level (66.32% by RAPD and 67.14% by ISSR). The highest values of PPL, expected heterozygosity, and Shannon's information index were in Pop1, while the lowest values were in Pop2. Both DNA markers revealed a short genetic distance between Pop1 and Pop2 (0.1424 by RAPD and 0.1904 by ISSR). Phylogenetic trees produced similar results, with Pop1, Pop2, and Pop5 in one group and Pop3 and Pop4 in another. There were no significant correlations between their genetic distances and their geographical distances. The highest genetic diversity was in Pop1 and the lowest was in Pop2, and genetic diversity at the species level was relatively low, but much higher than that at the population level. We recommended the establishment of a germplasm bank, in situ con-servation, and propagation of wild individuals. The present study will improve the evaluation, protection, and utilization of the population resources of C. wenyujin.

Relevance of E-cadherin expression to EGFR-TKI molecular targeted therapy sensitivity/resistance and its clinical significance

We examined the effect of E-cadherin expression on epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) molecular targeted therapy sensitivity/resistance. We treated MCF-7, MDA-MB-231, T24, SiHa, H460, SK-HEP-1, MHCC97-H, and THP-1 cells with the EGFR-TKIs PD153035 and gefitinib, and then tested the drug-resistance and sensitivity using the MTT method, calculated IC50 values for each cell line, and compared the results to E-cadherin content. The MTT assay was used to determine the survival rates of MCF-7, MDA-MB-231, T24, SiHa, H460, SK-HEP-1, MHCC97-H, and THP-1 cells upon the action of EGFR-TKI (PD153035, gefitinib). For PD153035, the IC50 in MCF-7, MDA-MB-231, T24, and SiHa cells differed from that of H460, SK-HEP-1, MHCC97-H, and THP-1 (P < 0.05). Following gefitinib treatment, the IC50 values of MCF-7, MDA-MB-231, T24, and SiHa cells differed from those of H460, SK-HEP-1, MHCC97-H, and THP-1 cells (P < 0.01). The survival rate of MCF-7, MDA-MB-231, T24, and SiHa cells clearly decreased with increasing drug concentration, indicating the cells were sensitive to the drugs and that E-cadherin expression was positive; however, H460, SK-HEP-1, MHCC97-H, and THP-1 cells showed no significant decreased with increasing drug concentration, indicating that they were resistant to the drugs and that E-cadherin expression was negative. The survival rate of epithelial tumor cells through the action of EGFR-TKI is related to E-cadherin expression. E-cadherin may play a significant role in the sensitivity regulation of EGFR molecular targeting treatment. E-cadherin may provide important clues for selecting proper EGFR-TKI molecular targeting treatment.

Successful treatment of refractory gastric antral vascular ectasia by distal gastrectomy: A case report

Gastric antral vascular ectasia (GAVE) is an uncommon and often neglected cause of gastric hemorrhage. The treatments for GAVE include surgery, endoscopy and medical therapies. Here, we report an unusual case of GAVE. A 72-year-old man with a three-month history of recurrent melena was diagnosed with GAVE. Endoscopy revealed the classical “watermelon stomach” appearance of GAVE and complete pyloric involvement. Melena reoccurred three days after argon plasma coagulation treatment, and the level of hemoglobin dropped to 47 g/L. The patient was then successfully treated with distal gastrectomy with Billroth II anastomosis. We propose that surgery should be considered as an effective option for GAVE patients with extensive and severe lesions upon deterioration of general conditions and hemodynamic instability.

Angled cavity photonic crystal laser diodes with tilted sidewalls for improving far-field patterns

Angled laser diodes based on the longitudinal photonic band crystal (PBC) waveguide are first proposed and fabricated at a wavelength of 905 nm. Tilted sidewalls are utilized to reflect the light downward, thus enlarging the transverse mode size. In the experiment, continuous wave (CW) output power of 630  mW/facet is achieved, and stable and narrow divergence angles are obtained in the fast and slow axes, simultaneously. The transverse angle is reduced by 44% compared with that of the conventional broad area (BA) laser based on the same wafer, and the lateral angle is only 1.65° with on-axis main-lobe emission. This device shows a promising future for laser emission with ultra-narrow divergence and easy fabrication.

[Metabonomic study on the anti-liver injury effect of Si-Ni-San on rats by using UPLC-MS/MS]

A UPLC-MS/MS method based on metabonomic skills was developed to study the serum metabolic changes of rats after acute liver injury induced by CCl4 and to evaluate the action mechanism of Si-Ni-San. The integrated data were exported for principal components analysis (PCA) by using SIMCA-P software, in order to find the potential biomarkers. It showed that clear separation of healthy control group, model group, silymarin group, Si-Ni-San group was achieved by using the PCA method. Nine significantly changed metabolites were identified as potential biomarkers of acute liver injury. Compared with the health control group, the model group rats showed higher levels of phenylalanine, tryptophan and GCDCA together with lower levels of LPC 16 : 0, LPC 18 : 0, LPC 18 : 1, LPC 16 : 1, LPC 20 : 4 and LPC 22 : 6. These changes of serum metabolites suggested that the disorders of amino acid metabolism, lipid metabolism, bile acid biosynthesis and anti-oxidative damage were related to acute liver injury induced by CCl4. Si-Ni-San might have the anti-liver injury effect on all these four metabolic pathways.

Fluorescent quantitative PCR of Mycobacterium tuberculosis for differentiating intestinal tuberculosis from Crohn's disease

Intestinal tuberculosis (ITB) and Crohn's disease (CD) are granulomatous disorders with similar clinical manifestations and pathological features that are often difficult to differentiate. This study evaluated the value of fluorescent quantitative polymerase chain reaction (FQ-PCR) for Mycobacterium tuberculosis (MTB) in fecal samples and biopsy specimens to differentiate ITB from CD. From June 2010 to March 2013, 86 consecutive patients (38 females and 48 males, median age 31.3 years) with provisional diagnoses of ITB and CD were recruited for the study. The patients' clinical, endoscopic, and histological features were monitored until the final definite diagnoses were made. DNA was extracted from 250 mg fecal samples and biopsy tissues from each patient. The extracted DNA was amplified using FQ-PCR for the specific MTB sequence. A total of 29 ITB cases and 36 CD cases were included in the analysis. Perianal disease and longitudinal ulcers were significantly more common in the CD patients (P<0.05), whereas night sweats, ascites, and circumferential ulcers were significantly more common in the ITB patients (P<0.05). Fecal FQ-PCR for MTB was positive in 24 (82.8%) ITB patients and 3 (8.3%) CD patients. Tissue PCR was positive for MTB in 16 (55.2%) ITB patients and 2 (5.6%) CD patients. Compared with tissue FQ-PCR, fecal FQ-PCR was more sensitive (X2=5.16, P=0.02). We conclude that FQ-PCR for MTB on fecal and tissue samples is a valuable assay for differentiating ITB from CD, and fecal FQ-PCR has greater sensitivity for ITB than tissue FQ-PCR.

[Chest X-ray findings in children with enterovirus 71 infection]

OBJECTIVE

To study the characteristics of the chest X-ray images in children infected with enterovirus 71.

METHODS

A total of 120 children with enterovirus 71 infection between April, 2010 and July, 2011 were classified into three groups according to the disease condition: mild (31 cases), severe (43 cases) and life-threatening (46 cases). The period from the onset of clinical symptoms to the first chest X-ray imaging examination and the results of the first chest X-ray findings were compared among the three groups.

RESULTS

The period from the onset of clinical symptoms to the first chest X-ray imaging examination in the mild, severe and life-threatening groups was 26-48 hrs (median 37 hrs), 10-36 h (median 23 hrs) and 2-36 hrs (median 19 hrs) respectively. Chest X-ray abnormalities were initially observed at 30 hrs after the onset of clinical symptoms in the mild group, at 23 hrs in the severe group and at 2 hrs in the life-threatening group (P<0.01). The mild group presented an initial imaging abnormality rate of 5.8%, the severe group 81.3% and the life-threatening group 100%. The life-threatening group showed a significantly higher initial X-ray abnormality rate than the other two groups (P<0.01). In terms of chest X-ray performance, the mild group usually presented lung marking thickening or vagueness. Most children in the severe group presented lung effusion and consolidation. Signs of pulmonary edema were found in the life-threatening group, and lesions in the life-threatening group were characterized by wide distribution and many lung lobe involvements.

CONCLUSIONS

The interval between the onset of clinical symptoms and the initial chest X-ray examination, the period of time of, and the onset of clinical symptoms, at which chest X-ray abnormalities, the abnormality rate and the severity of chest X-ray findings may be paralleled to the clinical situation in children with enterovirus 71 infection.

3-[(E)-1-(Benzyl-oxyimino)-eth-yl]-7-(3-methyl-but-2-en-yloxy)-2H-chromen-2-one

In the title compound, C₂₃H₂₃NO₄, the dihedral angle beween the chromen-2-one ring system and the benzene ring is 69.73 (10)° and the mol­ecule adopts an E conformation with respect to the C=N double bond. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds occur, generating R₂²(12) loops.

RAPD-based genetic diversities and correlation with morphological traits in Camellia (Theaceae) cultivars in China

Camellia is an economically important ornamental plant that has many uses, such as in beverages, foods and medicines. We examined 15 Camellia cultivars in Wenzhou, China, using RAPD markers and measurements of three traits (petal color, flower diameter, blooming period). PCR amplification with 15 random primers produced 1935 bands, observed at 88 amplification loci; 77% of the amplified loci were polymorphic, with a mean of 4.5 polymorphic loci per primer. The similarity coefficient ranged from 0.5419 to 0.7933 among the 15 samples; the lowest value was between Manao (C. reticulata) and Feibai FR (C. japonica), and the largest value was between Chidan (C. japonica) and Yuanyang FG (C. japonica). Cluster analysis divided the 15 cultivars into two groups at the similarity coefficient of 0.65. A correlation was found between RAPD markers and petal color in the first group. No correlation was found between RAPD markers and the other traits (flower diameter, blooming period). This study provides information useful for the identification, classification, phylogenesis, and breeding of Camellia cultivars.

Realization of a large J(2) quasi-2D spin-half Heisenberg system: Li(2)VOSiO(4)

Exchange couplings are calculated for Li(2)VOSiO(4) using the local-density approximation (LDA). While the sum of in-plane couplings J(1)+J(2) = 9.5+/-1.5 K and the interplane coupling J( perpendicular) approximately 0.2- 0.3 K agree with recent experimental data, the ratio J(2)/J(1) approximately 12 exceeds the reported value by an order of magnitude. Using geometrical considerations, high temperature expansions and perturbative mean field theory, we show that the LDA-derived exchange constants lead to a remarkably accurate description of the properties of these materials including specific heat, susceptibility, Néel temperature, and NMR spectra.

Chronic morphine exposure increases the phosphorylation of MAP kinases and the transcription factor CREB in dorsal root ganglion neurons: an in vitro and in vivo study

Tolerance to opiates reduces their effectiveness in the treatment of severe pain. Although the mechanisms are unclear, overactivity of pro-nociceptive systems has been proposed to contribute to this phenomenon. We have reported that the development of morphine tolerance significantly increased calcitonin-gene-related-peptide-like immunoreactivity (CGRP-IR) in primary sensory afferents of the spinal dorsal horn, suggesting that changes in pain-related neuropeptides in the dorsal root ganglion (DRG) neurons may be involved (Menard et al., 1996, J. Neurosci., 16, 2342-2351). Recently, we have shown that repeated morphine treatments induced increases in CGRP- and substance P (SP)-IR in cultured DRG, mimicking the in vivo effects (Ma et al., 2000, Neuroscience, 99, 529-539). In this study, we investigated the intracellular signal transduction pathways possibly involved in morphine-induced increases in CGRP- and SP-IR in DRG neurons. Repeated morphine exposure (10-20 microm) for 6 days increased the number of neurons expressing phosphorylated (p) mitogen-activated protein (MAP) kinases, including the extracellular signal-regulated kinase (pERK), c-jun N-terminal kinase (pJNK) and P38 (pP38 MAPK). The number of neurons expressing phosphorylated cAMP responsive element binding protein (pCREB) was also markedly increased in morphine-exposed cultured DRG neurons. pERK-, pP38-, pJNK- and pCREB-IR were colocalized with CGRP-IR in cultured DRG neurons. Naloxone effectively blocked these actions of morphine, whereas a selective MEK1 inhibitor, PD98059, inhibited the morphine-induced increase in the phosphorylation of ERK and CREB, and the expression of CGRP and SP. Moreover, in morphine-tolerant rats, the number of pCREB-, CGRP- and SP-IR neurons in the lumbar DRG was also significantly increased. These in vitro and in vivo data suggest that the phosphorylation of MAP kinases and CREB plays a role in the morphine-induced increase in spinal CGRP and SP levels in primary sensory afferents, contributing to the development of tolerance to opioid-induced analgesia.

Insulin-like growth factor-1 (IGF-1): a neuroprotective trophic factor acting via the Akt kinase pathway

Insulin-like growth factor-I (IGF-I) is a pleiotropic polypeptide with a wide range of actions in both central and peripheral nervous sytems. Over the past few years, we studied the trophic as well as neuromodulatory roles of IGF-I in the brain. Accumulated evidence indicates that IGF-I, apart from regulating growth and development, protects neurons against cell death induced by amyloidogenic derivatives, glucose or serum deprivation via the activation of intracellular pathways implicating phosphatidylinositide 3/Akt kinase, winged-helix family of transcription factor FKHRL1 phosphorylation or production of free radicals. The effects of IGF-I on neuroprotection, glucose metabolism and activity-dependent plasticity suggest the potential usefulness of this growth factor or related mimetics in the treatment of Alzheimer's disease and other neurodegenerative disorders.

Effects of amyloid peptides on cell viability and expression of neuropeptides in cultured rat dorsal root ganglion neurons: a role for free radicals and protein kinase C

Chronic pain caused by nerve injury and inflammation is more common in the elderly. However, mechanisms underlying this phenomenon are unclear. Higher sensitivity of sensory neurons to free radicals has been suggested as one possibility. The production of free radicals can be induced by various agents, including the highly toxic protein beta-amyloid (A beta), which is found in higher amounts in the brains of Alzheimer's Disease patients. In dorsal root ganglion (DRG) cultures exposed to A beta, we examined cellular toxicity and peptide expression, in particular calcitonin gene-related peptide (CGRP), a peptide which is abundantly expressed by nociceptive afferents and is known to be involved in pain processes. Exposure of cultured rat DRG neurons to A beta(25--35) or A beta(1--40) (10 or 20 microM for 24--96 h) increased trypan blue-stained cells in a concentration- and time-dependent manner, thus, indicating cellular toxicity. These treatments also increased the number of CGRP immunoreactive (IR) neurons while decreasing the number of neuropeptide Y- and galanin-IR neurons. The free radical scavenger, superoxide dismutase, attenuated both the toxicity and neuropeptide changes induced by A beta, thus, suggesting that oxidative stress probably contributes to these effects. Exposure of cultured DRG neurons to A beta also increased the number of protein kinase C alpha (PKC alpha)-IR neurons. The PKC inhibitors, chelerythrine chloride and Gö6976, significantly augmented A beta-induced cellular toxicity while attenuating the increases in CGRP-and PKC alpha-IR cells, supporting the notion of a protective role for PKC in A beta insults. These in vitro data suggest that A beta peptides may, in addition to causing neurotoxicity, regulate neuropeptide expression in primary afferents. This finding could be relevant to the higher incidence of neuropathic pain that occurs with ageing.

Morphine treatment induced calcitonin gene-related peptide and substance P increases in cultured dorsal root ganglion neurons

The mechanism of spinal tolerance to the analgesic effects of opiates is unclear at present. We have reported previously that calcitonin gene-related peptide-like immunoreactivity was significantly increased in primary afferents of the spinal dorsal horn during the development of morphine tolerance, suggesting that changes in the level of pain-related neuropeptides in dorsal root ganglion neurons may be involved [Menard D. P. et al. (1996) J. Neurosci. 16, 2342-2351]. In this study, we investigated if in vitro treatment with morphine can mimic the in vivo findings and induce increases in calcitonin gene-related peptide-like immunostaining in cultured dorsal root ganglion neurons from young (three-month-old) and middle-aged (10-month-old) adult rats. Following a repetitive exposure to morphine sulfate (1, 5, 10 microM) for six days, the number of calcitonin gene-related peptide- and substance P-immunoreactive neurons in cultured dorsal root ganglia from three- and 10-month-old rats was significantly increased. A lower concentration (0.5 microM) of morphine induced these increases only in dorsal root ganglion neurons from middle-aged rats. Morphine treatment was also found to increase the number of calcitonin gene-related peptide-immunoreactive neurons possessing multiple, long branches (i.e. with at least one branch >0.5mm). This apparent increase in the number of calcitonin gene-related peptide- and substance P-immunoreactive neurons observed following morphine treatment was blocked by naloxone, an opiate antagonist, indicating the involvement of genuine opioid receptors. No significant change in the number of neuropeptide Y- or galanin-immunoreactive neurons in cultured dorsal root ganglia was detected following any of these treatments. These data suggest that repeated exposure to morphine rather selectively increases calcitonin gene-related peptide- and substance P-like immunoreactivity in cultured dorsal root ganglion neurons. Moreover, the sensitivity to morphine-induced changes is greater in cultured dorsal root ganglion neurons from 10- compared to three-month-old rats. Hence, cultured dorsal root ganglion neurons can provide a model to investigate the cellular and molecular mechanisms underlying alterations in neuropeptide levels following repeated exposure to opiates and their relevance to the development of opioid tolerance.

DiSSiMiL: Diverse Small Size Mini-Libraries applied to simple and rapid epitope mapping of a monoclonal antibody

Methods for screening protein-protein interactions are useful in protein science and for the generation of drug leads. We set out to develop a simplified assay to rapidly test protein-protein interactions, with a library of 400 pentapeptides comprising the 20 natural amino acids at two variable positions followed by three glycines (NH2-X1X2GGG). The library was used to identify the epitope of monoclonal antibody (mAb) 10D11 directed against the HOXD4 protein. Three pentapeptide 'hits' were selected (VYGGG, PWGGG and WKGGG) from direct binding assays screening for pentapeptide-mAb interactions; and from assays using pentapeptides in solution to competitively block HOXD4-mAb interactions. Alignment of the three 'hit' pentapeptides to the HOXD4 sequence predicts the mAb 10D11 epitope as NH2-VYPWMK. Synthesis of NH2-VYPWMK hexapeptide confirmed this prediction; and an alanine scan of HOXD4 ablated binding by mAb 10D11 when amino acids in the putative epitope were mutated. We propose that these simplified but diverse libraries can be used for rapid epitope mapping of some mAbs, and for generating lead small peptide analogs that interfere with receptor-ligand or other protein-protein interactions, or with enzymatic activity.

Insulin-like growth factor-1-induced phosphorylation of the forkhead family transcription factor FKHRL1 is mediated by Akt kinase in PC12 cells

The Forkhead family transcription factor FKHRL1, a mammalian homolog of DAF16 in the nematode Caenorhabditis elegans, is an inducer of apoptosis in its unphosphorylated form and was recently reported as a substrate of Akt kinases. Insulin-like growth factor (IGF-1) is a potent stimulant of Akt kinase, leading to inhibition of the apoptotic pathway. In this study, we characterized the phosphorylation of FKHRL1 induced by IGF-1 in PC12 cells and various neuronal cell types and examined the potential role of Akt in this regard. IGF-1 rapidly induced the phosphorylation of Akt and FKHRL1 in PC12 cells. The phosphorylation of Akt and FKHRL1 induced by 10 nm IGF-1 was inhibited by the phosphatidylinositide 3-kinase (PI3K) inhibitors wortmannin (0.25-2 microm) and LY294002 (12.5-100 microm), but not by the MEK inhibitor PD98059 (50 microm) or the p70 S6 kinase pathway inhibitor rapamycin (50 nm), suggesting that the phosphorylation of FKHRL1 induced by IGF-1 is mediated by the PI3K pathway. As observed for IGF-1, an in vitro kinase assay with purified active Akt kinase demonstrated that the kinase is capable of directly phosphorylating FKHRL1 at Thr(32) and Ser(253), leading to inhibition of its pro-apoptotic properties. Moreover, transient expression of constitutively active Akt (MS-Akt, where MS is a myristylation signal) increased the phosphorylation of FKHRL1, whereas the expression of kinase-dead Akt (M179A Akt) attenuated the phosphorylation of FKHRL1 induced by 10 nm IGF-1 in PC12 cells. Interestingly, FKHRL1 co-immunoprecipitated with Akt in PC12 cells, indicating that these two proteins can associate in these cells. As IGF-1 also induced the phosphorylation of FKHRL1 in primary cortical and cerebellar neuronal cultures, these data, taken together, demonstrate that IGF-1, acting via the PI3K/Akt kinase pathway, can regulate the phosphorylation of FKHRL1, leading to inhibition of this apoptotic transcription factor in neuronal cells.

The Ginkgo biloba extract (EGb 761) protects and rescues hippocampal cells against nitric oxide-induced toxicity: involvement of its flavonoid constituents and protein kinase C

An excess of the free radical nitric oxide (NO) is viewed as a deleterious factor involved in various CNS disorders. Numerous studies have shown that the Ginkgo biloba extract EGb 761 is a NO scavenger with neuroprotective properties. However, the mechanisms underlying its neuroprotective ability remain to be fully established. Thus, we investigated the effect of different constituents of EGb 761, i.e., flavonoids and terpenoids, against toxicity induced by NO generators on cells of the hippocampus, a brain area particularly susceptible to neurodegenerative damage. Exposure of rat primary mixed hippocampal cell cultures to either sodium nitroprusside (SNP; 100 microM) or 3-morpholinosydnonimine resulted in both a decrease in cell survival and an increase in free radical accumulation. These SNP-induced events were blocked by either EGb 761 (10-100 microg/ml) or its flavonoid fraction CP 205 (25 microg/ml), as well as by inhibitors of protein kinase C (PKC; chelerythrine) and L-type calcium channels (nitrendipine). In contrast, the terpenoid constituents of EGb 761, known as bilobalide and ginkgolide B, as well as inhibitors of phospholipases A [3-[(4-octadecyl)benzoyl]acrylic acid (OBAA)] and C (U-73122), failed to display any significant effects. Moreover, EGb 761 (50 microm) CP 205 (25 microg/ml), and chelerythrine were also able to rescue hippocampal cells preexposed to SNP (up to 1 mM). Finally, EGb 761 (100 microg/ml) was shown to block the activation of PKC induced by SNP (100 microM). These data suggest that the protective and rescuing abilities of EGb 761 are not only attributable to the antioxidant properties of its flavonoid constituents but also via their ability to inhibit NO-stimulated PKC activity.

Stimulation of protein kinase C modulates insulin-like growth factor-1-induced akt activation in PC12 cells

Activation of protein kinase C (PKC) plays an important role in the negative regulation of receptor signaling, but its effect on insulin-like growth factor-1 (IGF-1) receptor signaling remains unclear. In this study, we characterized the intracellular pathways involved in IGF-1-induced activation of Akt and evaluated the effects of the PKC activator phorbol 12-myristate 13-acetate (PMA) on the Akt activation by IGF-1. IGF-1 induced a time- and concentration-dependent activation of Akt. The effect of IGF-1 was blocked by the phosphatidylinositide 3-kinase (PI3K) inhibitors LY294002 (50 micrometer) and wortmannin (0.5 micrometer), but not by the MEK inhibitor PD98059 (50 micrometer) or the p70 S6 kinase pathway inhibitor rapamycin (50 nm), suggesting that the stimulation of Akt by IGF-1 is mediated by the PI3K pathway. Interestingly, cotreatment with PMA (400 nm) attenuated IGF-1-induced activation of Akt. The attenuation was blocked completely by the PKC inhibitor GO6983 (0.5 micrometer), but only partially by the MEK inhibitor PD98059 (50 micrometer), indicating that MAPK-dependent and -independent pathways are involved. PMA induced the activation of PKC in PC12 cells, and this induction was blocked by GO6983. These data further support the role of PKC in the effect of PMA. Moreover, PKCdelta is likely involved in the action of PMA on the basis of data obtained using isoform-specific inhibitors such as rottlerin. PMA also decreased IGF-1-induced tyrosine phosphorylation of insulin receptor substrate-1 and its association with PI3K. Taken together, these results suggest, for the first time, that stimulation of PKC modulates IGF-1-induced activation of Akt.

Rediscovering good old friend IGF-I in the new millenium: possible usefulness in Alzheimer's disease and stroke

Much research has been done over the past two decades on the role of insulin-like growth factors I and II (IGF) in the maintenance of normal body homeostasis, especially in regard to various endocrine functions, growth and aging. For example, IGF-I is a well established promoter of tissue growth and has been used in the clinics for the treatment of growth related disorders, even being abused by athletes to enhance performance in competitions. In contrast, comparatively limited attention has been given to the potential significance of the IGFs in the central nervous system. Over the past few years, we have studied the trophic as well as neuromodulatory roles of the IGFs in the brain. IGF-I and IGF-II are potent modulators of acetylcholine release, IGF-I inhibiting release while IGF-II is a potent stimulant. Moreover, only the internalization of the IGF-I receptor complex was blocked by an inhibitor of phosphotyrosylation. This is in accordance with the differential nature of the IGF-I and IGF-II receptors, the former being a tyrosine kinase receptor while the later is a single transmembrane domain protein bearing binding sites for 6-mannose phosphate containing residues. The activation of IGF-I receptors protected neurons against cell death induced by amyloidogenic derivatives likely by an intracellular mechanism distinct from those involved in the regulation of acetylcholine release and neuronal growth. The stimulation of IGF-I receptors can activate intracellular pathways implicating a PI3/Akt kinase and CREB phosphorylation or modulate the production of free radicals. The effects, particularly those of IGF-I on key markers of the Alzheimer's (AD) brains namely cholinergic dysfunction, neuronal amyloid toxicity, tau phosphorylation and glucose metabolism suggest the potential usefulness of this growth factor in the treatment of neurodegenerative diseases. However, the poor bioavailability, enzymatic stability and brain penetration of IGF-I hamper progress in this regard. The recent development of a small, non-peptidyl mimetic of insulin able to directly activate the insulin receptor [Zhang, B., Salituro, G., Szalkowski, D., Li, Z., Zhang, Y., Royo, I., Vilella, D., Diez, M.T., Pelaez, F., Ruby, C., Kendall, R.L., Mao, X., Griffin, P., Calaycay, J., Zierath, J.R., Heck, J. V., Smith, R.G., Moller, D.E., 1999. Science, 284, 974-977] suggests that a similar strategy could be used for IGF-I and the IGF-I receptor leading to the characterization of IGF-I mimics of potential clinical usefulness.

Crosstalk between alpha-1A and alpha-1B adrenoceptors in neonatal rat myocardium: implications in cardiac hypertrophy

The myocardial effect of alpha-1A adrenoceptor (alpha-1 AR) agonists in neonatal rats are mediated by alpha-1A AR and not by alpha-1B AR, although both receptor subtypes are equally expressed; the functions of alpha-1B AR are not known. Here, we report that alpha-1 B ARs inhibit the activities of alpha-1A ARs in neonatal rat myocardium so that the inactivation of alpha-1 B ARs by chloroethylclonidine (CEC) potentiated the effects of nonselective alpha-1 AR agonist phenylephrine (PE) on myocardial protein synthesis and early gene (c-fos and c-jun) expression. CEC did not modify the hypertrophic effect of angiotensin II. The potentiation of the effects of PE by CEC was associated with a translocation of Ca(++)-dependent protein kinase C (PKC)alpha, which did not occur in the absence of CEC. Alpha-1A AR-selective agonist A61603 was approximately 1000-fold more potent than PE as a positive inotropic agent; it caused the translocation of PKC alpha, which was not affected by CEC. 5-Methylurapidil antagonized the effects of PE and A61603, suggesting that these were mediated via alpha-1A ARs. Alpha-1D AR antagonist BMY 7378 did not modify PE-induced translocation of PKC. CEC potentiated the effects of PE on Ca++ transients in Fura 2-AM-loaded dispersed cardiomyocytes, and this potentiation was prevented by nifedipine. In whole-cell patch-clamp recordings of cultured cardiomyocytes, CEC potentiated the effect of norepinephrine on Ca++ channel currents, which was blocked by 5-methylurapidil. We conclude that alpha-1A ARs are positively and alpha-1B ARs are negatively coupled to nifedipine-sensitive Ca++ channels, possibly via Gi protein, and this antagonistic relationship between alpha-A AR and alpha-1B AR in the neonatal heart might be required physiologically for normal alpha-1 AR-mediated responses and myocardial development.

Involvement of protein kinase C in nerve growth factor- and K-252a-stimulated calcium uptake into PC12 cells

Both nerve growth factor (NGF) and K-252a stimulate the uptake of calcium into PC12 cells. Stimulation by either is prevented by pretreatment of the cells with the tumor promoter phorbol 12-myristate 13-acetate (PMA), suggesting an involvement of protein kinase C in the stimulation. The effect of PMA is specific in that the calcium uptake stimulated by either the L-type channel agonist BAY K 8644 or by ATP is not altered in PMA-pretreated cells. An involvement of kinase C is also suggested by the inhibition of NGF- or K-252a-stimulated calcium uptake by the kinase C inhibitors staurosporine and calphostin C. Inhibition by the isoform-specific agents GO 6976 and thymeleatoxin implicates one of the classic calcium-sensitive isoforms of kinase C. The close similarity in the profiles of inhibition of NGF-stimulated and K-252a-stimulated calcium uptake by the various effectors suggests that NGF and K-252a act on calcium uptake through some of the same signaling elements.

Role of protein kinase C alpha in nerve growth factor-induced arachidonic acid release from PC12 cells

Nerve growth factor (NGF) increases arachidonic acid (AA) release by PC12 pheochromocytoma cells. To explore the role of protein kinase C (PKC) in this action of NGF, PKC was down-regulated by long-term treatment of the cells with phorbol 12-myristate 13-acetate (PMA). Such prolonged exposure to PMA (1 microM) resulted in the inhibition of NGF-induced AA release. Moreover, pretreatment of PC12 cells with the protein kinase inhibitor staurosporine or with calphostin C, a specific inhibitor of PKC, also blocks the increase of AA release induced by NGF. These data, as well as that PMA alone can induce AA release in PC12 cells, suggest that PKC is necessary for NGF-induced AA release. Immunoblot analysis of whole cell lysates by using antibodies against various PKC isoforms revealed that our PC12 cells contained PKCs alpha, delta, epsilon, and zeta. PMA down-regulation depleted PKCs alpha, delta, and epsilon, and partially depleted zeta. To see which isoform was involved in NGF-induced AA release, an isoform-specific PKC inhibitor was used. GO 6976, a compound that inhibits PKCs alpha and beta specifically, blocked NGF-induced AA release. In addition, thymeleatoxin, a specific activator of PKCs alpha, beta, and gamma, induced AA release from PC12 cells in amounts comparable with those seen with NGF. Taken together, these data suggest that PKC alpha plays a role in NGF-induced AA release.