Phenotypic dimorphism between honeybee queen and worker is regulated by complicated epigenetic modifications

Phenotypic dimorphism between queens and workers is an important biological characteristic of honeybees that has been the subject of intensive research. The enormous differences in morphology, lifespan, physiology, and behavior between queens and workers are caused by a complicated set of factors. Epigenetic modifications are considered to play an important role in this process. In this study, we analyzed the differences in chromosome interactions and H3K27ac and H3K4me1 modifications between the queens and workers using high-throughput chromosome conformation capture (Hi-C) and Chromatin immunoprecipitation followed by sequencing (ChIP-Seq) technologies. We found that the queens contain more chromosome interactions and more unique H3K27ac modifications than workers; in contrast, workers have more H3K4me1 modifications than queens. Moreover, we identified Map3k15 as a potential caste gene in queen-worker differentiation. Our results suggest that chromosomal conformation and H3K27ac and H3K4me1 modifications are involved in regulating queen-worker differentiation, which reveals that the queen-worker phenotypic dimorphism is regulated by multiple epigenetic modifications.

The diverging epigenomic landscapes of honeybee queens and workers revealed by multiomic sequencing

The role of the epigenome in phenotypic plasticity is unclear presently. Here we used a multiomics approach to explore the nature of the epigenome in developing honey bee (Apis mellifera) workers and queens. Our data clearly showed distinct queen and worker epigenomic landscapes during the developmental process. Differences in gene expression between workers and queens become more extensive and more layered during the process of development. Genes known to be important for caste differentiation were more likely to be regulated by multiple epigenomic systems than other differentially expressed genes. We confirmed the importance of two candidate genes for caste differentiation by using RNAi to manipulate the expression of two genes that differed in expression between workers and queens were regulated by multiple epigenomic systems. For both genes the RNAi manipulation resulted in a decrease in weight and fewer ovarioles of newly emerged queens compared to controls. Our data show that the distinct epigenomic landscapes of worker and queen bees differentiate during the course of larval development.

Feeding Asian honeybee queens with European honeybee royal jelly alters body color and expression of related coding and non-coding RNAs

Background and aims: The Asian honeybee (Apis cerana) and the European honeybee (Apis mellifera) are reproductively isolated. Previous studies reported that exchanging the larval food between the two species, known as nutritional crossbreeding, resulted in obvious changes in morphology, physiology and behavior. This study explored the molecular mechanisms underlying the honeybee nutritional crossbreeding. Methods: This study used full nutritional crossbreeding technology to rear A. cerana queens by feeding them with an A. mellifera royal jelly-based diet in an incubator. The body color and the expression of certain genes, microRNA, lncRNA, and circRNA among nutritional crossbred A. cerana queens (NQ), and control A. cerana queens (CQ) were compared. The biological functions of two target genes, TPH1 and KMO, were verified using RNA interference. Results: Our results showed that the NQ's body color turned yellow compared to the black control queens. Whole transcriptome sequencing results showed that a total of 1484, 311, 92, and 169 DEGs, DElncRNAs, DEmiRNAs, and DEcircRNAs, respectively, were identified in NQ and CQ, in which seven DEGs were enriched for three key pathways (tryptophan, tyrosine, and dopamine) involved in melanin synthesis. Interestingly, eight DElncRNAs and three DEmiRNAs were enriched into the key pathways regulating the above key DEGs. No circRNAs were enriched into these key pathways. Knocking down two key genes (KMO and TPH1) resulted in altered body color, suggesting that feeding NQ's an RNAi-based diet significantly downregulated the expression of TPH1 and KMO in 4-day-old larvae, which confirmed the function of key DEGs in the regulation of honeybee body color. Conclusion: These findings reveal that the larval diets from A. mellifera could change the body color of A. cerana, perhaps by altering the expression of non-coding RNAs and related key genes. This study serves as a model of epigenetic regulation in insect body color induced by environmental factors.

Extent and complexity of RNA processing in honey bee queen and worker caste development

The distinct honeybee (Apis mellifera) worker and queen castes have become a model for the study of genomic mechanisms of phenotypic plasticity. Here we performed a nanopore-based direct RNA sequencing with exceptionally long reads to compare the mRNA transcripts between queen and workers at three points during their larval development. We found thousands of significantly differentially expressed transcript isoforms (DEIs) between queen and worker larvae. These DEIs were formatted by a flexible splicing system. We showed that poly(A) tails participated in this caste differentiation by negatively regulating the expression of DEIs. Hundreds of isoforms uniquely expressed in either queens or workers during their larval development, and isoforms were expressed at different points in queen and worker larval development demonstrating a dynamic relationship between isoform expression and developmental mechanisms. These findings show the full complexity of RNA processing and transcript expression in honey bee phenotypic plasticity.

•

Honeybee caste differentiation has a complexity of RNA processing

•

Isoforms differentially express between queens and workers during larval development

•

Isoforms are formatted by a flexible alternative splicing system

•

Poly(A) tails are negatively correlated with isoform expression

[Clinicopathological characteristics of SMARCB1(INI1)-deficient sinonasal carcinoma]

Objective: To investigate the clinicopathological characteristics, diagnosis, differential diagnosis and prognostic factors of SMARCB1 (INI1)-deficient sinonasal carcinoma (SDSC). Methods: Sixteen cases of SDSC diagnosed in the Department of Pathology, Beijing Tongren Hospital from January 2016 to September 2020 were enrolled. Ninety-nine cases of small round cell malignant tumors of the head and neck were selected as the control, including poorly-differentiated squamous cell carcinoma (n=10), poorly-differentiated adenocarcinoma (n=5), undifferentiated carcinoma (SNUC, n=4), NUT carcinoma (n=5), neuroendocrine carcinoma (n=10), and other non-epithelial tumors [olfactory neuroblastoma (n=10), rhabdomyosarcoma (n=10), NK/T-cell lymphoma (n=10), malignant melanoma (n=10), Ewing's sarcoma/primitive neuroectodermal tumor (EWS/PNET, n=5)] and non-keratinizing undifferentiated nasopharyngeal carcinoma (n=20). The clinical and pathologic characteristics of SDSC, and immunohistochemical (IHC) expression of broad-spectrum CKpan, CK7, CK8/18, CK5/6, p63, p40, p16, INI1, NUT and neuroendocrine markers (Syn, CgA, CD56) were evaluated. In situ hybridization (ISH) was used to detect EBER and fluorescence in situ hybridization (FISH) to detect INI1 gene deletion. Results: The 16 cases of SDSC accounted for 1.3% (16/1 218) of all malignant sinonasal tumors in the author's unit during this time period, and 2.4% (16/657) of all malignant epithelial tumors. Microscopically, there was no clear squamous and adenomatous differentiation, but "rhabdoid-like" cells, are often seen. All SDSC cases were positive for CKpan and CK8/18, negative for INI1; Epstein-Barr virus was not detected by ISH; and INI1 gene deletion was observed in all 11 SDSC patients with FISH. Twelve cases were followed up for 3-47 months. One died of tumor-related diseases half a year after diagnosis, and the remaining patients were alive with tumor, the longest survival time was 47 months. Conclusion: SDSC should be differentiated from a variety of poorly-differentiated tumors in the sinonasal area. Histologically, SDSC has no clear differentiation, but the tumor cells are characteristically basal-like or rhabdoid-like, with non-specific vacuoles, translucent or vacuolar nuclei, prominent nucleoli and necrotic foci. They are negative for INI1 IHC staining, and FISH demonstrates INI1 gene deletion. The clinical prognosis is still unclear, further studies on its biologic behavior and treatment methods are warranted.

[Ruptured chordae tendineae of tricuspid valve in neonate with intractable persistent pulmonary hypertension: a case report and literature review]

Objective: To analyze the clinical characteristics and treatment of tricuspid valve prolapse caused by chordal rupture complicated with persistent pulmonary hypertension in neonates. Methods: The clinical data of a male neonate with tricuspid valve prolapse complicated with persistent pulmonary hypertension admitted to the Neonatal Intensive Care Unit of Children's Hospital of Hebei Province in November 2018 was analyzed retrospectively. Related literature up to September 2020 was searched with the strategy of "(neonate OR newborn) AND (tricuspid valve prolapse) AND (rupture OR necrosis) AND (papillary muscle OR chordae tendineae) AND (pulmonary hypertension)" in Wanfang, CNKI and PubMed database in Chinese and English. The characteristics of the disease were summarized. Results: A male full-term neonate was admitted due to presenting severe cyanosis for 9 hours. He was born by caesarean section and presented severe cyanosis and dyspnea at 10 min of ages, unresponsive to the positive airway pressure resuscitation. After 9 hours of mechanical ventilation, there was no improvement. Thus he was transferred to Children's Hospital of Hebei Province. On admission, the initial blood gas analysis showed an arterial partial pressure of oxygen of 22.5 mmHg (1 mmHg=0.133 kPa). The echocardiography revealed prolapsed anterior leaflet of tricuspid valve, severe tricuspid regurgitation (TR) and pulmonary artery hypertension, and right to left shunt via a patent foramen ovale. The arterial duct was closed. The chest X-ray was normal. The boy was treated with nitric oxide, milrinone, and continued mechanical ventilation initially. Addition of prostacyclin analog (treprostinil) on day 3 led to significant improvement of pulmonary blood flow, oxygenation, and stabilization, so that the extracorporeal membrane oxygenation therapy was avoided. At 11 months after birth, the boy underwent cardiac surgery. At surgery, the rupture of chordal tendineae in anterior leaflet of tricuspid valve was found. Tricuspid annuloplasty, valvuloplasty and repair of patent foramen ovale were successfully performed. The follow-up echocardiogram at postoperative 3 months showed only mild tricuspid insufficiency. The boy was well at last follow-up at 22 months of age with normal cognitive skill development. According to literature, 20 cases of papillary muscle or chordae tendineae rupture in neonates had been reported in 12 English papers. Among the total 21 neonates, there were 12 male infants and only one premature infant with gestational age of 33 weeks. They presented with profound cyanosis soon after birth. All of them received endotracheal intubation and mechanical ventilation. Other treatments included inhalation of nitric oxide, intravenous milrinone, vasoactive drugs, diuretics and prostacyclin, etc. Extracorporeal membrane oxygenation (ECMO) was used in 6 infants as a bridge to surgical treatment. Two cases reported earlier death of cardiopulmonary failure without operation and the rest 19 survived after surgery. The followed surgery or autopsy revealed that all of them had tricuspid valve prolapse, rupture of papillary muscle or chordae tendineae. Conclusions: The severe TR resulting from rupture of papillary muscle or chordate tendineae in neonates is rare and could cause severe hypoxemia. Early recognition, adequate cardiopulmonary support to stabilize the hemodynamic status and timely surgery can significantly reduce the mortality.

[Diagnosis of adult Philadelphia chromosome-like acute lymphoblastic leukemia by fluorescence in situ hybridization]

目的

建立应用荧光原位杂交技术（FISH）筛查成人Ph样急性淋巴细胞白血病（ALL）的体系。

方法

根据Ph样ALL的遗传学特征，设计了针对ABL1、ABL2、JAK2、EPOR、CRLF2、CSF1R、PDGFRB、P2RY8等基因断裂重排的FISH探针；对BCR-ABL1、ETV6-RUNX1、MLL基因断裂重排和E2A断裂重排均阴性的B-ALL，采用FISH进行Ph样ALL筛查，并结合流式免疫表型、靶向二代测序突变检测和RNA测序进行Ph样ALL诊断分析。

结果

2016年1月至2019年4月，南方医院血液科收治189例成人B-ALL，经FISH和（或）PCR检测，BCR-ABL1、ETV6-RUNX1、MLL断裂重排或E2A断裂重排阳性者共83例；其余106例患者接受Ph样ALL FISH探针筛查，其中，12例（11.3％）检出典型的Ph样ALL特异基因断裂重排，2例检出基因缺失。经RNA测序进一步验证，FISH检测Ph样ALL基因断裂重排结果灵敏度为71.4％，特异度为95.8％。综合免疫表型、靶向二代测序突变检测和RNA测序，共诊断融合基因阳性Ph样ALL 14例（13.2％）。

结论

FISH技术检测Ph样ALL具有较高的特异性，结合免疫表型和测序技术可完善诊断体系。

Transgenerational accumulation of methylome changes discovered in commercially reared honey bee (Apis mellifera) queens

Whether a female honey bee (Apis mellifera) develops into a worker or a queen depends on her nutrition during development, which changes the epigenome to alter the developmental trajectory. Beekeepers typically exploit this developmental plasticity to produce queen bee by transplanting worker larvae into queen cells to be reared as queens, thus redirecting a worker developmental pathway to a queen developmental pathway. We studied the consequences of this manipulation for the queen phenotype and methylome over four generations. Queens reared from worker larvae consistently had fewer ovarioles than queens reared from eggs. Over four generations the methylomes of lines of queens reared from eggs and worker larvae diverged, accumulating increasing differences in exons of genes related to caste differentiation, growth and immunity. We discuss the consequences of these cryptic changes to the honey bee epigenome for the health and viability of honey bee stocks.

A Maternal Effect on Queen Production in Honeybees

Influences from the mother on offspring phenotype, known as maternal effects, are an important cause of adaptive phenotypic plasticity [1, 2]. Eusocial insects show dramatic phenotypic plasticity with morphologically distinct reproductive (queen) and worker castes [3, 4]. The dominant paradigm for honeybees (Apis mellifera) is that castes are environmentally rather than genetically determined, with the environment and diet of young larvae causing caste differentiation [5-9]. A role for maternal effects has not been considered, but here we show that egg size also influences queen development. Queens laid significantly bigger eggs in the larger queen cells than in the worker cells. Eggs laid in queen cells (QE), laid in worker cells (WE), and 2-day old larvae from worker cells (2L) were transferred to artificial queen cells to be reared as queens in a standardized environment. Newly emerged adult queens from QE were heavier than those from the other two groups and had more ovarioles, indicating a consequence of egg size for adult queen morphology. Gene expression analyses identified several significantly differentially expressed genes between newly emerged queens from QE and those from the other groups. These included a disproportionate number of genes involved in hormonal signaling, body development, and immune pathways, which are key traits differing between queens and workers. That egg size influences emerging queen morphology and physiology and that queens lay larger eggs in queen cells demonstrate both a maternal effect on the expression of the queen phenotype and a more active role for the queen in gyne production than has been realized previously.

[Combined use of the Solitaire AB stent and Navien delivery catheter for mechanical thrombectory of acute vertebrobasilar artery occlusion]

Objective: To investigate the efficacy and safety of mechanical thrombectory with a tri-axial system of the solitaire AB stent through a Navien delivery catheter to treatment acute vertebrobasilar artery occlusion. Methods: The clinical data of 16 consecutive patients with acute ischemic stroke of vertebrobasilar artery occlusion treated with the Solitaire AB device from March 2016 to March 2018 in Department of Neurosurgery, the First Affiliated Hospital, Medical College of Shihezi University, were extracted and then retrospectively analyzed.Recanalization rate as well as complications after treatment were analysized. Also, neurological functions of the patients before and after operation 1 weeks, measured by National Institute of Health stroke scale (NIHSS) score were compared via t test and the clinical outcomes were assessed by modified Rankin score (mRS) at 90 days after operation. Results: There were 10 male and 6 female patients with a median age of 59 years (ranging from 45 to 78 years).Fourteen patients resulted in successfully recanalization, and 2 cases failed both of whose onset to sheath mean time were 8.5 hours.The NIHSS score at 7 days was 13±7, which was significantly decreased compared to the admission NIHSS score 24±4 (P=0.000).No symptomatic intracranial hemorrhage case was found after operation.At 90 days, 8 patients achieved good outcome (mRS 0 to 2), one patient died (mRS 6),two patients moderately seriously disabled (mRS 4).Three patients resulted in moderate outcome (mRS 3).In 3 cases of death,2 patients died due to failure in recanalization,another patient died of severe pulmonary infection. Conclusion: The results suggest that this technique of a tri-axial system used of the Solitaire AB stent through a Navien delivery catheter can effectively retrieve clots from the occlusive artery and improves functional outcome in patients with acute ischemic stroke of vertebrobasilar artery.

Aclidinium bromide inhibits human glioma cell proliferation, migration and invasion and promotes apoptosis via the PI3K/AKT signaling pathway

This study investigates the anti-cancer potential of Aclidinium bromide (INN) in glioblastoma. Glioblastoma cell lines U251 and U87 were treated with INN and its effects on cell migration and invasion were assessed by transwell migration and invasion assays., The effects of INN on proliferation and apoptosis were detected by CCK-8 kit and flow cytometry, and Western blotting determined anti-apoptotic proteins and signaling pathway changes. The results show that INN effectively suppressed proliferation, migration and invasion and induced apoptosis in U251 and U87 cells, respectively. Furthermore, the expression levels of the Bcl-2 anti-apoptotic protein was significantly decreased while Bax and caspase-3 expression were both increased in glioblastoma cells (all, p<0.05). Moreover, INN inactivated the PI3K/AKT signaling pathway by down-regulating the level of p-AKT, p-mTOR, P70 and CyclinD1 (all, p<0.05). In conclusion, our data suggests that INN could provide novel anticancer therapy in the treatment of glioblastoma.

Detection of hand-foot-mouth disease and its spatial-temporal Epidemiological characteristics with GIS platform

The aim of this study is to investigate the main category of hand-foot-mouth (HFM) virus and analyze the distribution characteristics and susceptible population of HFM disease in China. Infants who have had HFM disease for less than 7 days were selected from the First Affiliated Hospital of Guangxi Medical University, Guangxi, China. Various specimens were collected from the infants, and EV71 and CA16 nucleic acid detections were performed using fluorescence quantitative assay. The positive results of the specimens were compared to determine the components of the pathogen. Moreover, the data of the target cases were analyzed based on Geographic Information System (GIS) to obtain the spatial-temporal epidemiological features of HFM disease in China. The detection rate of HFM virus in the throat swab, feces, bleb fluid and cerebrospinal fluid were 75%, 81.13%, 85.71% and 25%, respectively, indicating that the detection rate of virus in the bleb fluid was the highest. When the detection was based on more than one specimen, it was found that the positive rate was higher compared to detection based on a single specimen. The positive detection rate of EV71 in the target specimens was significantly higher than that of CA16 and mixed infection. Moreover, CA16 infection was usually accompanied by EV71 infection. As to spatial-temporal distribution, hand-foot-month disease broke out in the South of China in April, then spread to the north, and diminished in July. There was a notable difference in the number of cases between different provinces. EV71 and CA16 are the main viruses inducing HFM disease, especially EV71. Fluorescence quantitative polymerase chain reaction with high sensitivity can be used to detect the copy number of viruses, which is applicable to the early diagnosis of HFM disease. The incidence of HFM disease is notably different according to the influence of time, geographical space, gender and the living conditions of the children. Early diagnosis and treatment based on scientific methods are needed to reduce the incidence of severe diseases and avoid death.

Practical Experiences and Lessons of Medical Response to Major Disasters in China

Introduction

The construction of a medical emergency response system for disasters, which plays an important role in medical emergency response to multiple catastrophic events, has been sped up in China since the 2008 Wenchuan earthquake. However, the implementation process has also exposed some problems, particularly the disaster relief system.

Methods

In this review, we summarised and analysed emergency medical rescue efforts after major disasters in China in recent years, including 2008 Wenchuan earthquake, 2010 Yushu earthquake, ‘7.23’ Yongwen major railway line accident and 2013 Lushan earthquake.

Results

Critically wounded persons after Wenchuan and Lushan earthquake were managed according to the “four centralised strategies of care”, namely casualties, experts, resources and patients, which were designed to make the best use of limited resources. The collection of disaster response resources was not the sooner the better. The vulnerability and anti-disaster capacity of quake-hit zone and the degree of matching between critical elements of a response system and its supporting systems should be considered. The training of rescue teams in rural and high-altitude areas should be strengthened. Non-government organisations, the government and the public should join together to deal with the disaster.

Conclusions

In this paper, we evaluate the disaster relief systems in China through a retrospective analysis of medical practice of catastrophic events in recent years. This review suggests that there are a lot of experiences and lessons on how to prepare and respond to disasters in China, especially those in plateau mountain region and those considering emergency responses to catastrophic events. (Hong Kong j.emerg.med. 2015;22:270-280)

Evaluation of the Revised Trauma Score in Predicting Outcomes of Trauma Patients

Introduction

The revised trauma score (RTS) was developed more than 20 years ago. Few studies investigated its usefulness in predicting trauma outcomes. This is especially true for the weighted version of RTS (RTS-w). The aim of this study was to test the predicting power of RTS-w for the trauma outcomes including mortality, admission to intensive care unit (ICU), hospital length of stay and ICU length of stay through a comparison with Injury Severity Score (ISS).

Methods

Descriptive data, variables related to the trauma scores and outcomes were collected. The statistical performance of RTS-w and ISS in predicting the trauma outcomes using receiver operating characteristics (ROC) curves and the area under the curve (AUC) with 95% confidence interval and p value were calculated. The Hosmer-Lemeshow chi-squared statistic was performed to measure its calibration.

Results

A total of 3323 patients were enrolled in the study. RTS-w was significantly better than ISS in predicting mortality of trauma patients (AUC: 0.934 vs.0.880, p<0.0001). However, for the other three outcomes, i.e. admission to ICU, hospital length of stay and intensive care unit length of stay, the performance of RTS-w was inferior to ISS.

Conclusions

The RTS-w is a better predictor of mortality than ISS. But its ability to predict other trauma outcomes is not as good as ISS. More studies are needed to identify the predictive ability of RTS-w for the outcomes other than mortality. Besides, updating the coefficients of the formula may make RTS-w more accurate.

Analysis of hemorrhagic fever with renal syndrome and its pathogenic gene sequence based on geographic information system

This study analyzed the temporal-spatial distribution characteristics, epidemiological characteristics and gene sequences of hemorrhagic fever with renal syndrome (HFRS) in Guangxi, with the intention of providing a theoretical and technical support for the prevention of HFRS. A map of the incidence of HFRS of different cities in Guangxi was drawn up using the Geographic Information System (GIS) to investigate the epidemiological characteristics and infection source of HFRS between 2013 and 2016. Guangxi has a low incidence of HFRS, and autumn and winter are the main high-incidence seasons. Cases of HFRS were reported in all regions in Guangxi except Laibin city between 2013 and 2016. The distribution of cases in the four years suggested that Guilin, Nanning, Hechi and Wuzhou were the main infected regions, especially the local areas in the north of Guilin. The nucleotide and amino acid of S fragment and M fragment of Hantaviruses (HV) detected were highly homologous, and no obvious variation was found. Through analyzing the space-time characteristics, epidemiological characteristics and gene sequence of HFRS in Guangxi, it was found that areas rich in water, grass and moisture, such as paddy fields, are the main active areas for the host of HFRS.

Inhibition of subcutaneously implanted human pituitary tumor cells in nude mice by LRIG1

The aim of this study was to explore the inhibition of subcutaneously implanted human pituitary tumor cells in nude mice by LRIG1 and its mechanism. For this study, athymic nude mice were injected with either normal pituitary tumor RC-4B/C cells or LRIG1-transfected RC-4B/C cells. We then calculated the volume inhibition rate of the tumors, as well as the apoptosis index of tumor cells and the expression of Ras, Raf, AKt, and ERK mRNA in tumor cells. Tumor cell morphological and structural changes were also observed under electron microscope. Our data showed that subcutaneous tumor growth was slowed or even halted in LRIG1-transfected tumors. The tumor volumes were significantly different between the two groups of mice (χ2 = 2.14, P < 0.05). The tumor apoptosis index was found to be 8.72% in the control group and 39.7% in LRIG1-transfected mice (χ2 = 7.59, P < 0.05). The levels of Ras, Raf, and AKt mRNA in LRIG1-transfected RC-4B/C cells were significantly reduced after transfection (P < 0.01). Transfected subcutaneous tumor cells appeared to be in early or late apoptosis under an electron microscope, while only a few subcutaneous tumor cells appeared to be undergoing apoptosis in the control group. In conclusion, the LRIG1 gene is able to inhibit proliferation and promote apoptosis in subcutaneously implanted human pituitary tumors in nude mice. The mechanism of LRIG1 may involve the inhibition of the PI3K/ Akt and Ras/Raf/ERK signal transduction pathways.

Functional calcium imaging in zebrafish lateral-line hair cells

Sensory hair-cell development, function, and regeneration are fundamental processes that are challenging to study in mammalian systems. Zebrafish are an excellent alternative model to study hair cells because they have an external auxiliary organ called the lateral line. The hair cells of the lateral line are easily accessible, which makes them suitable for live, function-based fluorescence imaging. In this chapter, we describe methods to perform functional calcium imaging in zebrafish lateral-line hair cells. We compare genetically encoded calcium indicators that have been used previously to measure calcium in lateral-line hair cells. We also outline equipment required for calcium imaging and compare different imaging systems. Lastly, we discuss how to set up optimal imaging parameters and how to process and visualize calcium signals. Overall, using these methods, in vivo calcium imaging is a powerful tool to examine sensory hair-cell function in an intact organism.

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.

AKR1B10, a good prognostic indicator in gastric cancer

BACKGROUND AND OBJECTIVES

The aim of the study was to investigate the correlation between AKR1B10 expression and clinicopathological features of gastric cancer (GC).

METHODS

Real-time polymerase chain reaction (RT-PCR) was performed to determine AKR1B10 mRNA expression. AKR1B10 protein levels were measured by immunohistochemistry.

RESULTS

RT-PCR analysis confirmed that AKR1B10 was significantly down-regulated in gastric cancer compared with paired, normal mucosa. Immunohistochemistry revealed that the percentage of AKR1B10-positive specimens was lower in gastric carcinoma compared with normal specimens. The frequency of AKR1B10-positive GC specimens was higher in patients with tumor size <5 cm, no lymph node metastasis, no distant metastasis and lower tumor stages The mean survival time for patients in the AKR1B10-positive group was significantly higher compared with the AKR1B1-negative group. The 5-year survival rate for the AKR1B10-positive group was also significantly higher than for the AKR1B1-negative group. Cox regression analysis revealed that AKR1B10 expression is an independent prognostic factor of GC.

CONCLUSIONS

Expression of AKR1B10 in gastric cancer was significantly associated with tumor size, lymph node metastasis, distance metastasis and TNM stage, and AKR1B10 may be a good prognostic indicator in gastric cancer.

Sphingosine-1-phosphate is a possible fibrogenic factor in gluteal muscle fibrosis

Gluteal muscle contracture (GMC) is a chronic fibrotic disease of gluteal muscles due to multiple etiologies. The main pathologic process is characterized by proliferation of fibroblasts and excessive accumulation of collagen in the extracellular matrix of the muscle. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and has been reported to be associated with various fibrotic diseases. However, the role of S1P in GMC remains unknown. Here in this article, High-performance liquid chromatography and immunohistochemistry were applied to evaluate S1P localization and expression in clinical samples from patients with GMC, Quantitative real time PCR, Western blot, and enzyme-linked immunosorbent assay were used to explore the link between transforming growth factor-beta1 (TGF-beta1), plasminogen activator inhibitor-1 (PAI-1) and S1P. The results showed that S1P was enhanced in contraction band (CB) tissues. Studies using the cell proliferation and transformation assay indicated that exogenous S1P stimulated CB fibroblast proliferation in a time-dependent manner and in higher concentration also in a dose-dependent manner. Furthermore, we demonstrated that S1P not only promoted collagen type I production, but also up-regulated mRNA and protein expression of transforming growth factor-beta1 and plasminogen activator inhibitor-1. These findings suggest that S1P may regulate increased synthesis of collagen and other fibrogenic factors, and significantly contributes to the process of gluteal muscle scarring in patients with GMC.

Pathogenicity and distribution of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs

The pathogenesis of highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) strain (HuN4) is poorly understood. Therefore, highly pathogenic PRRSV strain (HuN4) and its derivative strain (HuN4-F112) (obtained by propagation in MARC145 cells for 112 passages) were inoculated into a total of 48 PRRSV-sero-negative pigs (age: 4-5 weeks) by the intranasal route. Virological, pathological and in situ hybridization analyses were performed. The results exhibited that pigs infected with HuN4 showed a loss of appetite, decrease in body weight, raised body temperature and respiratory symptoms, along with interstitial pneumonia lesions. In the HuN4 group, multifocal interstitial pneumonia with macrophage infiltration was found in the lung. The lesions in the lymph node were characterized by collapsed follicles, depletion of germinal centres and reduction in lymphocytes. Perivascular cuffing and glial nodules were observed in the brains of some pigs. By comparison, the HuN4-F112 group had milder lesions. PRRSV was detected in macrophages, alveolar epithelial cells and vascular endothelial cells in the tonsil and lymph nodes. The PRRSV amounts in the pigs infected with HuN4 were 10(5) -10(9) copies/ml in the blood and 10(10) -10(11) copies/g in the lung tissues, whereas the virus amounts with HuN4-F112 were 10(2.15) -10(3.13) copies/ml in the blood and 10(3.0) -10(3.6) copies/g in the lung. Our results demonstrate that the PRRS HuN4 virus infects alveolar epithelial cells, macrophages and vascular endothelial cells causing diffuse alveolar damage and lymph node necrosis. Its higher pathogenicity compared with HuN4-F112 virus may be explained in part by higher replication rate in the previously mentioned organs.

Studies of lithium ion dynamics in paramagnetic cathode materials using (6)Li 1D selective inversion methods

The effectiveness of two different selective inversion methods is investigated to determine timescales of Li ion mobility in paramagnetic Li intercalation materials. The first method is 1D exchange spectroscopy, which employs a 90°-τ(1)-90° sequence for selective inversion of a Li resonance undergoing site exchange. The experiment is most easily applied when the first delay period, τ(1), is set to the frequency difference between two resonances undergoing ion exchange. This enables the determination of ion hopping timescales for single exchange pair systems only. To measure ion dynamics in systems having more than one exchange process, a second selective inversion method was tested on two paramagnetic Li intercalation materials. This second technique, replaces the 90°-τ(1)-90° portion of 1D EXSY with a long, selective shaped pulse (SP). Two paramagnetic solid-state materials, which are both cathode materials for lithion ion batteries, were chosen as model compounds to test the effectiveness of both the selective inversion methods. The first compound, Li(2)VPO(4)F, was chosen as it hosts two Li sites with 1-exchange process. The second model compound is a 3-site, 3-exchange process system, Li(2)VOPO(4). For the 2-site material, Li(2)VPO(4)F, the timescales of the single A-B exchange process were found to be within error of one another regardless of the inversion method. For the 3 Li-site material Li(2)VOPO(4), the three exchange processes, AB, BC, and AC, were found to be on the millisecond timescale as revealed using the SP method. These timescales were determined over a variable temperature range where activation energies extended from 0.6 ± 0.1 eV up to 0.9 ± 0.2 eV.

Evaluation of normal fetal pulmonary veins from the early second trimester by enhanced-flow (e-flow) echocardiography

OBJECTIVES

To explore the feasibility of using enhanced-flow (e-flow) imaging technology to identify fetal pulmonary veins and establish gestational age-specific reference values at 12-40 weeks' gestation.

METHODS

The pulmonary venous internal diameter, peak systolic and diastolic flow velocities and visualization rate were analyzed in 332 normal fetuses at 12-40 weeks of gestation. Two-dimensional gray-scale (2D) ultrasound, color Doppler and e-flow imaging were used to detect the pulmonary veins in the four-chamber view by taking the lung as the penetration window.

RESULTS

The pulmonary veins could be visualized as early as 12 weeks' gestational age by e-flow imaging. The right and left pulmonary venous internal diameters and peak systolic and diastolic flow velocities increased with increasing gestational age. Between 12 and 40 gestational weeks, the internal diameter and both the systolic and diastolic flow velocities of the fetal right pulmonary vein were significantly larger than were those of the left vein (P < 0.05). Of 118 fetuses at 12-22 gestational weeks, the visualization rate of the four pulmonary veins (left superior and inferior, right superior and inferior) was 5.9% (7/118) by 2D ultrasound, 41.5% (49/118) by color Doppler and 61.9% (73/118) by e-flow imaging. The visualization rate by e-flow imaging was significantly higher than that using the other two techniques (P < 0.001).

CONCLUSION

e-flow imaging is apparently a feasible and promising technology with which to identify the fetal pulmonary veins in the early stages of the second trimester.

Effect of melittin on potassium currents and action potential in ventricular myocytes of guinea pig

AIM

To examine the effects of melittin (Mel), the major component of bee venom, on delayed rectifier K+ current (Ik), inward rectifier K+ current (Ikl) and action potential (AP) in guinea pig ventricular myocytes.

METHODS

Ik, Ikl, and AP were recorded using the whole-cell patch-clamp technique.

RESULTS

The action potential duration (APD) was shortened by Mel in a concentration-dependent manner. Mel 0.05, 0.1, 0.2 mumol.L-1 shortened APD50 from (520 +/- 55) to (459 +/- 91) (n = 5, P > 0.05), (385 +/- 102) (n = 5, P < 0.01), and (281 +/- 81) ms (n = 5, P < 0.01), respectively; and APD90 from (613 +/- 96) to (536 +/- 93) (n = 5, P > 0.05), (467 +/- 96) ms (n = 5, P < 0.01), and (354 +/- 95) ms (n = 5, P < 0.01), respectively. Mel increased the amplitude of Ik also in a concentration-dependent manner. Mel 0.05, 0.1, 0.2 mumol.L-1 increased Ik from (295 +/- 109) to (371 +/- 142) (n = 5, P < 0.05), (467 +/- 180) (n = 5, P < 0.05), (552 +/- 248) pA (n = 5, P < 0.05), respectively at testing potential of + 40 mV. But no significant effect of Mel on Ikl was observed at these concentrations.

CONCLUSION

Mel significantly increased Ik in a concentration-dependent manner which contributed to shortening of APD.

[A quantitative analysis of renal pathology in the children with anaphylactoid purpura nephritis (APN)]

OBJECTIVE

To provide the theoretical value for the treatment and prognostic judgement of APN.

METHODS

All cases were scored on the pathologic change of glomeruli and tubules.

RESULTS

The pathologic scores of glomeruli in 30 cases were as follows: no one on Grade 0; 6(20%) on Grade 1; 17(56.7%) on Grade 2 and 7 (23.3%) on Grade 3. The pathologic scores of tubule were: Grade 0 was 2(6.7%); Grade 1 was 6(20%); Grade 2 was 14(46.7%); Grade 3 was 8(26.7%). There was positive correlation between glomerulus and tubule pathologic degree(r = 0.783, P < 0.01). The pathologic score of nephrotic syndrome in clinical manifestation was higher than that of non-nephrotic syndrome(P < 0.01). There was no significant difference in glomerular pathologic score between the simple urinary protein group and acute glomerulonephritis(AGN) group(P > 0.05), but tubular pathologic score in simple urinary proteins group was higher than that of AGN and essential hematuria group (P < 0.01, P < 0.05). The pathologic score of kidney(including glomerulus and tubule) was positively correlated with the disease course(r = 0.563, P < 0.01), but not with serum urea nitrogen and creatinine(r = 0.281, r = 0.236, P > 0.05).

CONCLUSION

Serious tubular pathologic changes(not only glomerular pathologic change, but also tubular pathologic change in the APN children) were found in the patients with nephrotic syndrome and simple urinary proteins. Long-term urinary protein and the recurrence of the disease may be the important risk factor in kidney pathologic of APN.

Blocking effects of heteroclitin D and gomisin J on L-type calcium channels in ventricular cells of guinea pig

AIM

To study the effects of heteroclitin D (HD) and gomisin J (GJ), two lignans from Kadsura medicinal plants, on L-type calcium channels in ventricular cells of guinea pig.

METHODS

The calcium currents were measured by whole-cell patch-clamp recording technique.

RESULTS

HD 1 and 10 mumol/L decreased the L-type calcium current from (770 +/- 155) to (482 +/- 104) and (384 +/- 85) pA, respectively. GJ 10 mumol/L inhibited calcium current from (822 +/- 169) to (436 +/- 143) pA. Neither HD nor GJ affected the steady-state activation curve. But they had impact on steady-state inactivation curve. HD 10 mumol/L changed the half inactivation voltage (V0.5) from -22.7 to -40.9 mV, and slope factor (kappa) from 10.2 to 20.6 (n = 4 cells from 3 guinea pigs, P < 0.05). GJ 10 mumol/L changed the V0.5 from -17.7 to -33.3 mV, and kappa from 15.9 to 27.8 (n = 5 cells from 3 guinea pigs, P < 0.05).

CONCLUSION

HD and GJ inhibited L-type calcium channels.

Non-ketotic hyperosmolar coma complicating steroid treatment in childhood nephrosis

Two nephrotic children treated with prednisone developed steroid-induced diabetes and non-ketotic hyperosmolar coma (NKHC). Both patients presented with convulsions, coma and shock. The glucose concentration of the cerebrospinal fluid was 425 mg/dl and 622 mg/dl, respectively. Both patients had no diabetic family history, but had been treated with prednisone for 4 and 8 months, receiving total doses of 6.6 and 10.8 g, respectively. Despite conventional therapy, both patients deteriorated rapidly and died several hours later. Steroid-induced diabetes associated with NKHC is a rare but serious complication of steroid therapy.

[New techniques of cultivating Ganoderma lucidum (W. Curt.:Fr)Karst.,Rev. with woodlog]

Imitating wild cultivation of Ganoderma lucidum with short-woodlog is a method of cultivating artificial G. lucidum developed in recent years. The method can be applied to large scale production. This paper shows that section-inoculating and impregnating with steamed shortwoodlog indoors and soil-cover cultivating under large shed are important in the cultivation.

Abnormal hemoglobins in the Silk Road region of China

A review is presented of the occurrence of 24 abnormal hemoglobins (13 alpha-chain variants and 11 beta-chain variants) in populations in the Silk Road area of Northwestern China. Most frequently occurring were Hb D-Punjab [beta 121(GH4)Glu----Gln] in Uygurs, Kazaks, and Khalkhas, Hb G-Taipei [beta 22(B4)Glu----Gly] in persons of the Han nationality, and Hb G-Coushatta [beta 22 (B4)Glu----Ala] in the Uygurs, Kazaks, Hans, and related nationalities. The data suggest that these variants likely originated in Central Asia, in the Han nationality of China, and in the minorities of northern China, respectively. Other variants occurred at considerably lower frequencies and were imported from other countries or arose as independent mutations. Two variants [Hb Tashikuergan or alpha 19(AB1)Ala----Glu; Hb Tianshui or beta 39(C5) Gln----Arg] were observed for the first time. The data from this study of the many variants support the movements of various populations in this area, as reported in numerous historical documents.

Establishment and characterization of 12S adenoviral E1A immortalized rat submandibular gland epithelial cells

Rat submandibular gland (RSMG) cells have been immortalized with a retrovirus vector which encodes the adenovirus 12S E1A gene product. The immortalized cells were epithelial-like in nature and displayed a beta-adrenergic coupled rise in intracellular cAMP upon exposure to norepinephrine. Western- and lectin-blotting experiments of cell lysates demonstrated the presence of blood group A-reactive oligosaccharides. Such oligosaccharides are characteristic of RSMG mucin-glycoproteins. These cells appear to be suitable for use in analysis of cell-specific factors which regulate RSMG glycosylation.

Evidence for two modes of Ca2+ entry following muscarinic stimulation of a human salivary epithelial cell line

We have investigated muscarinic receptor-operated Ca2+ mobilization in a salivary epithelial cell line. HSG-PA, using an experimental approach which allows independent evaluation of intracellular Ca2+ release and extracellular Ca2+ entry. The carbachol (Cch) dose response of intracellular Ca2+ release indicates the involvement of a single, relatively low-affinity, muscarinic receptor site (K0.5 approximately equal to 10 or 30 microM, depending on the method for [Ca2+]i determination). However, similar data for Ca2+ entry indicate the involvement of two Cch sites, one consistent with that associated with Ca2+ release and a second higher affinity site with K0.5 less than or equal to 2.5 microM. In addition, the Ca2+ entry response observed at lower concentrations of Cch (2.5 microM) was completely inhibited by membrane depolarization induced with high K+ (greater than 55 mM) or gramicidin D (1 microM), while membrane depolarization had little or no effect on Ca2+ entry induced by 100 microM Cch. Another muscarinic agonist, oxotremorine-M (100 microM; Oxo-M), like Cch, also induced an increase in the [Ca2+]i of HSG-PA cells (from 72 +/- 2 to 104 +/- 5 nM). This response was profoundly blocked (approximately 75%) by the inorganic Ca2+ channel blocker La3+ (25-50 microM) suggesting that Oxo-M primarily mobilizes Ca2+ in these cells by increasing Ca2+ entry. Organic Ca2+ channel blockers (verapamil or diltiazem at 10 microM, nifedipine at 1 microM), had no effect on this response. The Oxo-M induced Ca2+ mobilization response, like that observed at lower doses of Cch, was markedly inhibited (approximately 70-90%) by membrane depolarization (high K+ or gramicidin D).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) on muscarinic receptor-induced Ca2+ mobilization in a human salivary epithelial cell line

We have investigated the effect of W-7, a calmodulin (CaM) antagonist, on Ca2+ mobilization in a human salivary epithelial cell line, HSG-PA, after muscarinic receptor stimulation. In a medium containing 1.5 mmol/l Ca2+, W-7 reduced both the maximum peak increase in cytosolic Ca2+ [( Ca2+]i) which follows stimulation by carbachol (Cch, 100 mumol/l) and the sustained nature of the response. Using an experimental approach which allows separate visualization of the intracellular Ca2+ release and extracellular Ca2+ entry phases, W-7 was shown preferentially to inhibit Ca2+ release. At 100 mumol/l W-7, Cch-induced Ca2+ release was completely inhibited, but Cch-induced Ca2+ entry was partially (approximately 40%) maintained. This W-7 residual Ca2+ entry response was abolished when cells were depolarized with high K+ or gramicidin D. W-7 also substantially inhibited Cch-induced inositol trisphosphate (IP3) production (approximately 5%). W-5, a less potent CaM antagonist than W-7, had markedly smaller effects on Cch-induced Ca2+ mobilization and IP3 formation. W-7 (100 mumol/l) completely blocked (comparable to 10 mumol/l atropine) the binding of the muscarinic antagonist [3H] quinuclidinyl benzilate (QNB) to muscarinic receptors on cell membranes, whereas Cch (at 100 mumol/l) had minimal effects on ligand binding. W-7 and W-5 were equipotent in their ability to inhibit [3H] QNB binding. These results suggest that W-7 reduces Ca2+ mobilization in HSG-PA cells by a mechanism which likely involves the antagonism of a CaM regulatory step(s) but may also involve at least a partial blockade of the muscarinic receptor.

Beta-adrenergic responsiveness in a human submandibular tumor cell line (A253)

Salivary epithelial functions are regulated by the autonomic nervous system. In this regard, we have been studying the morphology and neuroreceptor composition of A253, an immortal cell line isolated from a human submandibular carcinoma (Giard et al., JNCI, 51:1417-1421, 1973). Phase contrast and electron microscopic observations indicate that A253 cells are of epithelial origin. Physiologically, A253 cells possess beta-adrenergic, but not alpha-adrenergic or muscarinic-cholinergic receptors. The beta-adrenergic receptors (BARs) are composed primarily of a single class of high affinity, beta 2-subtype receptors as judged by [3H]dihydroalprenolol antagonist binding studies. The BARs are functional inasmuch as isoproterenol stimulation increases both intracellular cAMP content and [3H]mannose incorporation into endogeneous glycoproteins. Differences in ultrastructure and neuroreceptor composition between A253 and other immortal salivary tumor cell lines are discussed.

Muscarinic receptor regulation of Ca2+ mobilization in a human salivary cell line

We have studied receptor-mediated Ca2+ mobilization in an established exocrine epithelial cell line (HSG-PA) derived from a human submandibular gland. These cells possess a single class of high-affinity muscarinic cholinergic receptors identified using [3H]-quinuclidinyl-benzilate (Kd = 0.17 +/- 0.07 nmol/l; Bmax = 37 +/- 2 fmol/mg protein; n = 3). The muscarinic agonist carbachol elicits a concentration dependent increase of [3H]-inositol trisphosphate in HSG-PA cells (100 mumol/l; greater than 2 fold by 30 s). Carbachol also results in a rapid, approximately 5-fold increase in cytosolic [Ca2+]. This response is made up of two components, one arising from the release of intracellular Ca2+ (La3+ insensitive; independent of extracellular [Ca2+]), the other from the entry of extracellular Ca2+ (La3+ sensitive; dependent on extracellular [Ca2+]). These Ca2+ mobilizing mechanisms are completely blocked by the muscarinic antagonist atropine (10 mumol/l) but unaffected by several voltage-dependent Ca2+ channel antagonists (verapamil, nifedipine, diltiazem) and by membrane depolarization (incubation in 55 mmol/l KCl). These results demonstrate that HSG-PA cells respond to muscarinic stimulation by mobilizing Ca2+ from an intracellular store and via a receptor-operated Ca2+ entry pathway.

Beta-adrenergic control of cell volume and chloride transport in an established rat submandibular cell line

Rat submandibular cells treated with methylcholanthrene are able to be propagated in continuous culture while retaining beta-adrenergic responsiveness. A specific clone, RSMT-A5, has been isolated and studied in detail. RSMT-A5 cells possess beta-adrenergic receptors (BARS) as judged by [3H]-dihydroalprenolol ([3H]-DHA) binding studies. [3H]-DHA binds to RSMT-A5 membranes in a specific and saturable manner with respect to time and [3H]-DHA concentration. Specific binding is saturable within three min of incubation, and a Scatchard analysis reveals a single class of high affinity binding sites with an equilibrium dissociation constant of 0.62 +/- 0.03 nM and a receptor density of 101 +/- 4 fmole/mg protein. Antagonist competition studies indicate that the BARs are primarily of the beta 2-subtype. The BARs are functional since isoproterenol stimulation results in an increased intracellular cAMP content, marked morphological change, and decreased cell volume and chloride content. These same responses can be evoked by treating RSMT-A5 cells with 8-bromo-cAMP. Ion transport inhibitors such as bumetanide (an inhibitor of Na/K/Cl cotransport), SITS and DIDS (inhibitors of chloride-bicarbonate exchange), amiloride (an inhibitor of Na-H exchange), ouabain (an inhibitor of Na/K-ATPase), and dipyridamole and 9-anthracene carboxylic acid (chloride channel blockers) fail to inhibit the isoproterenol-stimulated change in chloride content. The effects of either isoproterenol or 8-bromo-cAMP on both chloride content and cell volume can be inhibited by the chloride channel blocker N-phenylanthranilic acid, however. Taken together, our results indicate that RSMT-A5 cells possess a beta-adrenergic receptor system which controls intracellular volume and chloride content by modulating transport processes that are 1) cAMP-responsive and 2) inhibitable by the putative chloride channel blocker N-phenylanthranilic acid.

Characteristics of alpha 1-adrenergic receptors in a rat salivary cell line, RSMT-A5

1. Membrane preparations obtained from RSMT-A5, an established rat submandibular cell line, possess alpha 1-adrenergic receptors as judged by [3H]prazosin binding studies. Scatchard analysis reveals a single class of binding sites with an equilibrium dissociation constant (Kd) of 0.052 nM and a receptor density (Bmax) of 104 fmol/mg protein. 2. These receptors are functional since stimulation by epinephrine results in an increased rate of phosphatidylinositol turnover which is blocked by both phentolamine and phenoxybenzamine. 3. Phenoxybenzamine (10(-5) M) irreversibly blocks 95% of the receptors within 2 min. A kinetic analysis shows that the receptors subsequently reappear at a rate of 6 fmol/mg protein/h. The calculated rate constant for receptor clearance (Kc) is 0.027 hr-1, and the half life (t 1/2) of the receptor is 26 hr. 4. These results are comparable to those reported for alpha 1-adrenergic receptors in the BC3H-1 smooth muscle cell line and suggest that alpha 1-adrenergic receptors in cultured cells, from diverse tissues, display similar characteristics.

Sympathetic denervation fails to produce beta adrenergic supersensitivity in adult rat parotid gland

Parotid acinar cells, prepared from pharmacologically sympathectomized adult rats (reserpine, 0.1 mg/kg/day for 1 week), display decreased responsiveness to beta adrenergic stimulation in vitro compared to cells from control and surgically sympathectomized rats. Both methods of denervation increase amylase content (amylase activity per microgram of DNA). Percent release of amylase activity and percent release of CCl3COOH-precipitable [14C]leucine were used as indicators of protein secretion. Exposure of cells from pharmacologically sympathectomized rats to the beta adrenergic agonist, isoproterenol, resulted in a marked reduction in receptor-coupled secretion (67% and 75% relative to controls, respectively). 8-Bromo-cyclic AMP, like isoproterenol, was unable to surmount this reserpine-induced inhibition of stimulated secretion, suggesting that an alteration in receptor-adenylate cyclase coupling is not responsible for the observed secretion defect. Cells prepared from surgically sympathectomized rats displayed modest decreases in stimulated secretion when the same secretory markers were monitored (30% and 25% relative to controls, respectively). The number of beta adrenoreceptors [( 3H]dihydroalprenolol binding sites) increased (35%), with no change in binding affinity, in membrane preparations from reserpine-treated rats. Thus, the observed inhibition of beta adrenergic agonist-induced secretion is not likely the result of alterations in beta adrenergic receptor characteristics. Short-term (1 week) surgical denervation had no effect on the number of beta adrenergic receptor sites; however, an increase in ligand binding affinity was noted. The decrease in the apparent Kd (30%) was not the result of a shift in receptor subtype as determined by competition studies with specific beta-1 (atenolol) and beta-2 (ICI 118,551) receptor antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein kinase C differentially inhibits muscarinic receptor operated Ca2+ release and entry in human salivary cells

We investigated the effects of phorbol myristate acetate on muscarinic receptor-induced Ca2+ release from intracellular stores and extracellular entry in a human salivary duct cell line, HSG-PA. Phorbol myristate acetate (approximately 10(-7) M) blocked both Ca2+ release and Ca2+ entry induced by the muscarinic agonist carbachol. This blockade was the result of the activation of protein kinase C since 4 alpha-phorbol 12,13-didecanoate, which lacks the ability to activate protein kinase C, did not inhibit Ca2+ mobilization responses to carbachol. Importantly, at lower phorbol myristate acetate concentrations (approximately 10(-9) M), carbachol-induced Ca2+ release was blocked, but carbachol-induced Ca2+ entry was maintained. These results show that carbachol-induced Ca2+ entry does not occur via an intracellular store and that protein kinase C plays a role in a feedback control mechanism for muscarinic-induced Ca2+ mobilization at different levels.