[Mechanism of Tianhe Zhuifeng Ointment in treating rheumatoid arthritis with syndrome of internal obstruction and cold-dampness and compatibility principles based on "disease-syndrome-formula" association network]

This study aims to explore the mechanism of Tianhe Zhuifeng Ointment in treating rheumatoid arthritis(RA) with syndrome of internal obstruction and cold-dampness and the compatibility characteristics based on the "disease-syndrome-formula" association network. A gene set associated with the clinical symptoms of RA was collected from Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine v2.0(TCMIP v2.0). The different expression gene set of RA with syndrome of internal obstruction and cold-dampness was screened out by transcriptomic expression profile detection and bioinformatics data mining of the comparison of RA patients with syndrome of internal obstruction and cold-dampness and healthy volunteers. The chemical composition information of 35 Chinese medicines from Tianhe Zhuifeng Ointment was collected from TCMIP v2.0 and Traditional Chinese Medicine Bank(TCMBank). The candidate targets were predicted based on the similarity principle of compounds structure. The interactive network of "related gene of RA with syndrome of internal obstruction and cold-dampness-candidate target of Tianhe Zhuifeng Ointment" was constructed. The core network targets were screened out by topological characteristics of calculating network, and the functional exploration was carried out based on Kyoto Encyclopedia of Genes and Genomes(KEGG) and Reactome Pathway Database. The compatibility mechanisms of various efficacy groups of Tianhe Zhuifeng Ointment were further explored. The results showed that the candidate targets of Tianhe Zhuifeng Ointment were mainly involved into the modules of "immune-inflammation" regulation, nervous system function, cell function, and substance and energy metabolism, etc. The mechanisms of various efficacy groups emphasized on different aspects. The group of dispelling wind and removing dampness-dredging channels and activating collaterals, the group of extinguishing wind and stopping convulsions, and the group of pungent analgesia regulated "immune-inflammation" system by warming meridians and dissipating cold. The group of activating blood and resolving stasis and the group of strengthening sinews and bones regulated "immune-inflammation" system by activating blood and dredging channels. The group of dispelling wind and removing dampness-dredging channels and activating collaterals, the group of extinguishing wind and stopping convulsions, the group of activating blood and resolving stasis, the group of strengthening sinews and bones, and the group of clearing heat and draining water affected the nervous system by invigorating Qi-blood and benefiting spirit. The group of dispelling wind and removing dampness-dredging channels and activating collaterals and the group of extinguishing wind and stopping convulsions regulated cell function and substance and energy metabolism by dispelling wind and eliminating cold-dampness. The group of activating blood and resolving stasis and the group of strengthening sinews and bones regulated the cell function and substance and energy metabolism by activating blood and strengthening sinews and bones. The results showed that Tianhe Zhuifeng Ointment exerted the comprehensive efficacy of dispelling wind, removing dampness, activating blood, removing stasis, warming meridians, dredging channels, and strengthening sinews and bones through adjusting the imbalance of "immune-inflammation", regulating nervous system, cell function, and interfering with substance and energy metabolism, thus improving the syndrome of internal obstruction and cold-dampness. The findings of this study laid foundations for clarifying the therapeutic characteristics and clinical orientation of Tianhe Zhuifeng Ointment.

[Biological connotation of four traditional Chinese medicine syndromes of rheumatoid arthritis based on "disease-syndrome-symptom" association network]

The present study explored the biological connotation of traditional Chinese medicine(TCM) syndromes of rheumatoid arthritis(RA) from the "disease-syndrome-symptom" association network. RA patients with four TCM syndromes(dampness-heat obstruction, phlegm-stasis obstruction, Qi-blood deficiency, and liver and kidney deficiency), three for each type, were assigned as the RA TCM syndrome group, and three healthy volunteers as the normal control group. The differential gene sets of four syndromes were screened out through transcriptome expression profiling and bioinformatics mining. The relevant gene sets of syndrome-related clinical symptoms were collected from TCMIP v2.0(http://www.tcmip.cn/). The "disease-syndrome-symptom" association networks of four RA syndromes were established by using the intersection genes of syndrome-related differential genes and symptom-related genes, and the key network target genes of each syndrome were screened out and the corresponding biological functions were mined through topological feature calculation and enrichment analysis. The genes associated with clinical symptoms such as vasculitis, joint pain, and fever in the damp-heat obstruction syndrome ranked the top, and the key network target genes of this syndrome were most significantly enriched in the pathways related to material and energy metabolism and thermal reaction biological processes. The clinical symptom-related genes of the phlegm-stasis obstruction syndrome were most significantly enriched in the pathways related to "immunity-inflammation", nervous system regulation, and sensory response. The clinical symptoms such as hypoglycemia, hypotension, weight loss, palpitation, and arrhythmia in Qi-blood deficiency syndrome were predominant, and its key network target genes were most significantly enriched in the pathways related to the nervous system and "immunity-inflammation" response. The abnormal symptoms in the liver and kidney in the liver and kidney deficiency syndrome were commonly seen, and its key network target genes were most significantly enriched in the "immunity-inflammation" regulatory pathways, and liver and kidney development and metabolic response. In conclusion, the differences and connections of the biological basis between different TCM syndromes of RA are in line with the theoretical interpretation of TCM on the etiology and pathogenesis of RA. This study summarized the objective essence of syndromes to a certain extent from the "disease-syndrome-symptom" association network and is expected to provide a theoretical basis for the discovery of serum biomarkers of RA syndromes.

Effect of integrated Traditional Chinese and Western Medicine on gout

OBJECTIVE

To evaluate the curative effect of integrated Traditional Chinese and Western Medicine on gout, and to investigate the therapy timing and exact treatment options of integrated medicine.

METHODS

Totally 860 patients were enrolled, including 460 patients with intermittent gout, 200 patients with active Traditional Chinese Medicine (TCM) syndrome (TCM syndrome score ≥ 6) and 200 patients with stable TCM syndrome (score < 6). They were randomly divided into intervention and control groups. The control group was treated according to Western Medicine guidelines. The intervention group was treated with integrated Traditional Chinese and Western Medicine. The efficacy of TCM syndrome, joint pain score, joint swelling score, ESR, C-reactive protein, serum uric acid, liver and kidney function, and the duration of remission of TCM syndrome were compared between the two groups before and after treatments.

RESULTS

For the patients with stable TCM syndrome, there was no significant difference in the effective rate and inefficiency between the intervention group and the control group. For the active type, the effective rate of the intervention group is better than the control group significantly. For the stable type, there was no significant difference between the intervention group and the control group in improving the scores of joint pain and swelling, reducing the level of ESR, C-reactive protein, serum uric acid and improving liver and kidney function. For the active type, the differences between the two groups were significant. The stable stage of gout in the intervention group was longer than the control group.

CONCLUSION

For the gout patients with stable TCM syndrome in the acute stage of gout, we can use TCM treatment or Western Medicine alternatively; for the patients with active TCM syndrome, the scheme of combination of Traditional Chinese and Western Medicine can be applied, with the better curative effect than any medicine alone.

Genome-wide association study reveals a quantitative trait locus and two candidate genes on Sus scrofa chromosome 5 affecting intramuscular fat content in Suhuai pigs

Intramuscular fat content (IFC) is an essential quantitative trait of meat, affecting multiple meat quality indicators. A certain amount of IFC could not only improve the sensory score of pork but also increase the flavour, tenderness, juiciness and shelf-life. To dissect the genetic determinants of IFC, two methods, including genome-wide efficient mixed-model analysis (GEMMA) and linkage disequilibrium adjusted kinships (LDAKs), were used to carry out genome-wide association studies for IFC in Suhuai pig population. A total of 14 and 18 significant single nucleotide polymorphisms (SNPs) were identified by GEMMA and LDAK, respectively. The results of these two methods were highly consistent and all 14 significant SNPs in GEMMA were detected by LDAK. Seven of the 18 SNPs reached the genome-wide significance level (P < 9.85E-07) while 11 cases reached the suggestive significance level (P < 1.77E-05). These significant SNPs were mainly distributed on Sus scrofa chromosome (SSC) 5, 3, and 7. Moreover, one locus resides in a 2.27 Mb (71.37-73.64 Mb) region on SSC5 harbouring 13 significant SNPs associated with IFC, and the lead SNP (rs81302978) also locates in this region. Linkage disequilibrium (LD) analysis showed that there were four pairs of complete LD (r² = 1) among these 13 SNPs, and the remaining 9 SNPs with incomplete LD (r² ≠ 1) were selected for subsequent analyses of IFC. Association analyses showed that 7 out of 9 SNPs were significantly associated with IFC (P < 0.05) in 330 Suhuai pigs, and the other 2 SNPs tended to reach a significant association level with IFC (P < 0.1). The phenotypic variance explained (PVE) range of these 9 SNPs was 0.92-3.55%. Meanwhile, the lead SNP was also significantly associated (rs81302978) with IFC (P < 0.05) in 378 commercial hybrid pigs (Pietrain × Duroc) × (Landrace × Yorkshire) (PDLY), and the PVE was 1.38%. Besides, two lipid metabolism-relevant candidate genes, the leucine rich repeat kinase 2 (LRRK2) and PDZ domain containing ring finger 4 (PDZRN4) were identified in the 2.27 Mb region on SSC5. In conclusion, our results may provide a set of markers useful for genetic improvement of IFC in pigs and will advance the genome selection process of IFC on pig breeding programmes.

[Clinical characteristics of anti-CV2 antibody-associated neurological diseases]

This study reviewed the clinical data of patients who were hospitalized in the Department of Neurology of Henan Provincial People's Hospital from January 2017 to October 2020. A total of 46 patients with positive serum anti-CV2 antibody were included. The average age of the patients was (54±15) years old, with a male to female ratio of 1.88∶1. Twenty-six patients were diagnosed with paraneoplastic neurological syndrome (PNS). The most malignant tumors were thymoma, small cell lung cancer, and prostate cancer. The most common PNS included myasthenia gravis, subacute cerebellar degeneration, and subacute/chronic sensorimotor neuropathies. Twenty non-PNS patients exhibited subacute/old cerebral infarction, Parkinson's disease, Alzheimer's disease, and so on. Among them, brain magnetic resonance imaging (MRI) of 10 cases showed different degrees of white matter demyelination, some of which were accompanied by brain atrophy. The current study found that the positive predictive value of anti-CV2 antibody for the diagnosis of PNS was 56.5%, which was relatively weak. As an accompanying antibody, it may be a coincidence, and it may also be related to the involvement of family members in the pathological process of the diseases.

Epidemiology and outcomes of geriatric and non-geriatric patients with drug allergy labels in Hong Kong

INTRODUCTION

Adverse drug reactions are more common in geriatric patients than in younger patients, but there have been insufficient studies concerning the epidemiology or burden of drug allergy labels in geriatric patients. We prospectively investigated the prevalence and outcomes of geriatric patients with drug allergy labels in a cohort of hospitalised patients.

METHODS

Patients admitted to a regional hospital over a 6-month period were recruited for this study. All patients with drug allergy labels were prospectively followed until discharge; clinical data were anonymously extracted for analyses. Patients were categorised into either geriatric (aged ≥65 years) or non-geriatric (aged <65 years) groups. Demographic characteristics, clinical outcomes, and prevalences of drug allergy labels were compared between groups.

RESULTS

There were 4361 admissions involving 3641 patients during the 6-month study period. Overall, 492 patients (13.5%) had drug allergy labels, consisting of 151 non-geriatric patients (30.7%) and 341 geriatric patients (69.3%). The prevalence of drug allergy labels did not significantly differ between geriatric and non-geriatric patients (13.5% vs 13.5%, P=0.976). Significantly more patients in the geriatric group had drug allergy labels to cardiovascular system drugs (15.5% vs 4.6%, P=0.001). Geriatric patients had a significantly lower rate of direct discharge from the hospital (73.0% vs 88.1%, P<0.001) and required transfers to convalescent or rehabilitation care for further management.

CONCLUSIONS

More than 13% of hospitalised geriatric patients had drug allergy labels. The leading causes of drug allergy labels were similar between geriatric and non-geriatric patients. Geriatric patients with drug allergy labels had significantly more labelled allergies to cardiovascular system drugs and adverse clinical outcomes.

Hong Kong Institute of Allergy and Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases joint consensus statement 2018 on vaccination in egg-allergic patients

Vaccination of egg-allergic individuals has been a historical concern, particularly for influenza and measles-mumps-rubella-varicella vaccines that are developed in chicken egg embryos or chicken cell fibroblasts. The egg proteins in these vaccines were believed to trigger an immediate allergic reaction in egg-allergic individuals. However, recently published international guidelines have updated their recommendations and now state that these vaccines can be safely administered to egg-allergic individuals. This joint consensus statement by the Hong Kong Institute of Allergy and the Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases summarises the updates and provides recommendations for local general practitioners and paediatricians. Hong Kong Institute of Allergy and Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases joint consensus statement 2018 on vaccination in egg-allergic patients Background.

Identification of an (AC)n microsatellite in the Six1 gene promoter and its effect on production traits in Pietrain × Duroc × Landrace × Yorkshire pigs

The Sine oculis homeobox 1 (Six1) gene is important for skeletal muscle growth and fiber specification; therefore, it is considered as a promising candidate gene that may influence porcine growth and meat quality traits. Nevertheless, the association of Six1 with these processes and the mechanisms regulating its expression remain unclear. The objectives of this study were to identify variant sites of Six1 in different pig breeds, conduct association analysis to evaluate the relationship between polymorphisms of these variants and porcine production traits in Pietrain × Duroc × Landrace × Yorkshire commercial pigs, and explore the potential regulatory mechanisms of Six1 affecting production traits. A total of 12 variants were identified, including 10 single- nucleotide variations (SNVs), 1 insertion- deletion (Indel), and 1 (AC)n microsatellite. Association analysis demonstrated that the SNV, g.1595A>G, was significantly associated with meat color (redness, a*); individuals with the G allele had greater a* values (P < 0.05). Moreover, our results demonstrated that the (AC)n polymorphism in the Six1 promoter was significantly associated with weaning weight (P < 0.05), carcass weight (P < 0.05), and thoracic and lumbar back fat (P < 0.01).In addition, we found that the (AC)n variant was closely related with Six1 expression levels and demonstrated this polymorphism on promoter activity by in vitro experiments. Overall, this study provides novel evidence for elucidating the effects of Six1 on porcine production traits as promising candidate and describes two variants with these traits, which are potential reference markers for pig molecular breeding. In addition, our data on the relationship between porcine Six1 expression and the polymorphic (AC)n microsatellite in its promoter may facilitate similar studies in other species.

Fowl adenovirus serotype 4: Epidemiology, pathogenesis, diagnostic detection, and vaccine strategies

Fowl adenovirus (FAdV) serotype-4 is highly pathogenic for chickens, especially for broilers aged 3 to 5 wk, and it has emerged as one of the foremost causes of economic losses to the poultry industry in the last 30 years. The liver is a major target organ of FAdV-4 infections, and virus-infected chickens usually show symptoms of hydropericardium syndrome. The virus is very contagious, and it is spread both vertically and horizontally. It can be isolated from infected liver homogenates and detected by several laboratory diagnostic methods (including an agar gel immunodiffusion test, indirect immunofluorescence assays, counterimmunoelectrophoresis, enzyme-linked immunosorbent assays, restriction endonuclease analyses, polymerase chain reaction (PCR), real-time PCR, and high-resolution melting-curve analyses). Although inactivated vaccines have been deployed widely to control the disease, attenuated live vaccines and subunit vaccines also have been developed, and they are more attractive vaccine candidates. This article provides a comprehensive review of FAdV-4, including its epidemiology, pathogenesis, diagnostic detection, and vaccine strategies.

Immunoglobulin G4-related disease in Hong Kong: clinical features, treatment practices, and its association with multisystem disease

INTRODUCTION

Immunoglobulin G4-related disease remains an under-recognised and evolving disease. Local data are sparse and previous publications have been limited to individual case reports or case series only. We conducted this study to review the clinical features, treatment practices, and factors associated with multisystem involvement in Hong Kong. We described the clinical features and treatment modalities of the largest cohort of immunoglobulin G4-related disease in our locality thus far.

METHODS

We retrospectively evaluated all patients with immunoglobulin G4-related disease between January 2003 and December 2015 in Queen Mary Hospital and combined this with patient data extracted from previous local publications. We analysed the clinical features, treatment practices, and factors associated with the number of organ systems involved.

RESULTS

A total of 104 patients (55 from Queen Mary Hospital and 49 from literature review) were identified. Patients were predominantly older men (mean [standard deviation] age, 61.9 [12.7] years; male-to-female ratio=3:1) and 94.4% had elevated pre-treatment serum immunoglobulin G4 levels. Hepatobiliary and pancreatic system (40.4%), salivary gland (33.7%), lymph node (29.8%), and eye (19.2%) were the most common organ systems involved. Lymphadenopathy was associated with glucocorticoid use (odds ratio=2.65; 95% confidence interval, 1.08-6.54; P=0.034). Pre-treatment serum immunoglobulin G4 levels correlated with the number of organ systems involved (β=0.347; P=0.004) and, specifically, more associated with patients having salivary gland involvement than those without (mean, 1109 mg/dL vs 599 mg/dL; P=0.012).

CONCLUSION

We identified pre-treatment serum immunoglobulin G4 to be associated with multisystem disease, especially with salivary gland involvement, highlighting its potential for disease prognostication and monitoring. Increased physician awareness and multidisciplinary efforts are required for early diagnosis and optimal management of this masquerading disease.

Identification of new single nucleotide polymorphisms affecting total number born and candidate genes related to ovulation rate in Chinese Erhualian pigs

The Chinese Erhualian pig has the highest record for litter size in the world. However, the genetic mechanism of its high prolificacy remains poorly understood. In our study, large phenotypic variations in litter size were found among Erhualian sows. Significant differences in total number born (TNB) and corpora lutea numbers were observed between sows with high and low estimated breeding values (EBVs) for TNB. To identify single nucleotide polymorphisms (SNPs) associated with TNB, a selective genomic scan was conducted on 18 sows representing the top 10% and 18 sows representing the bottom 10% of EBVs of 177 sows using Illumina Porcine SNP60 genotype data. Genome-wide fixation coefficient (F_ST ) values were calculated for each SNP between the high- and low-EBV groups. A total of 154 SNPs were significantly differentiated loci between the two groups. Of the top 10 highest F_ST SNPs, rs81399474, rs81400131 and rs81405013 on SSC8 and rs81434499 and rs81434489 on SSC 12 corresponded to previously reported QTL for litter size. The other five SNPs, rs81367039 on SSC2, rs80891106 on SSC7, rs81477883 on SSC12 and rs80938898 and rs80971725 on SSC14, appeared to be novel QTL for TNB. Significant associations between rs81399474 on SSC8 and TNB were confirmed in 313 Erhualian sows. Forty genes were identified around the top 10 highest F_ST SNPs, of which UCHL1, adjacent to rs81399474, and RPS6KB1 and CLTC, adjacent to rs81434499, have been reported to affect the ovulation rate in pig. The findings can advance understanding of the genetic variations in litter size of pigs.

SARS CoV subunit vaccine: antibody-mediated neutralisation and enhancement

1. A SARS vaccine was produced based on recombinant native full-length Spike-protein trimers (triSpike) and efficient establishment of a vaccination procedure in rodents. 2. Antibody-mediated enhancement of SARS-CoV infection with anti-SARS-CoV Spike immune-serum was observed in vitro. 3. Antibody-mediated infection of SARS-CoV triggers entry into human haematopoietic cells via an FcγR-dependent and ACE2-, pH-, cysteine-protease-independent pathways. 4. The antibody-mediated enhancement phenomenon is not a mandatory component of the humoral immune response elicited by SARS vaccines, as pure neutralising antibody only could be obtained. 5. Occurrence of immune-mediated enhancement of SARS-CoV infection raises safety concerns regarding the use of SARS-CoV vaccine in humans and enables new ways to investigate SARS pathogenesis (tropism and immune response deregulation).

Optimization models for siting water quality monitoring stations in a catchment

A water quality monitoring network (WQMN) must be designed so as to adequately protect the water quality in a catchment. Although a simulated annealing (SA) method was previously applied to design a WQMN, the SA method cannot ensure the solution it obtained is the global optimum. Therefore, two new linear optimization models are proposed in this study to minimize the deviation of the cost values expected to identify the possible pollution sources based on uniform cost (UC) and coverage elimination uniform cost (CEUC) schemes. The UC model determines the expected cost values by considering each sub-catchment being covered by which station, while the CEUC model determines the coverage of each station by eliminating the area covered by any upstream station. The proposed models are applied to the Derchi reservoir catchment in Taiwan. Results show that the global optimal WQMN can be effectively determined by using the UC or CEUC model, for which both results are better than those from the SA method, especially when the number of stations becomes large.

Association of CD247 with systemic lupus erythematosus in Asian populations

OBJECTIVE

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. CD247 (CD3Z, TCRZ) plays a vital role in antigen recognition and signal transduction in antigen-specific immune responses, and is known to be involved in SLE pathogenesis. Weak disease association was reported for genetic variants in this gene in Caucasian studies for SLE, Crohn's disease and systemic sclerosis, but its role as a genetic risk factor was never firmly established.

METHODS

In this study, using a collection of 612 SLE patients and 2193 controls of Chinese ethnicity living in Hong Kong in a genome-wide study, single nucleotide polymorphisms (SNPs) in and around CD247 were identified as being associated with SLE. The two most significant SNPs in this locus were selected for further replication using TaqMan genotyping assay in 3339 Asian patients from Hong Kong, Mainland China, and Thailand, as well as 4737 ethnically and geographically matched controls.

RESULTS

The association of CD247 with SLE in Asian populations was confirmed (rs704853: odds ratio [OR] = 0. 81, p = 2.47 × 10(-7); rs858543: OR = 1.10, p = 0.0048). Patient-only analysis suggested that rs704853 is also linked to oral ulcers, hematologic disorders and anti-double-stranded DNA (dsDNA) antibody production.

CONCLUSION

A significant association between variants in CD247 and SLE was demonstrated in Asian populations. Understanding the involvement of CD247 in SLE may shed new light on disease mechanisms and development of new treatment paradigms.

Siting analyses for water quality sampling in a catchment

Pollution loads discharged from upstream development or human activities significantly degrade the water quality of a reservoir. The design of an appropriate water quality sampling network is therefore important for detecting potential pollution events and monitoring pollution trends. However, under a limited budgetary constraint, how to site an appropriate number of sampling stations is a challenging task. A previous study proposed a method applying the simulated annealing algorithm to design the sampling network based on three cost factors including the number of reaches, bank length, and subcatchment area. However, these factors are not directly related to the distribution of possible pollution. Thus, this study modified the method by considering three additional factors, i.e. total phosphorus, nitrogen, and sediment loads. The larger the possible load, the higher the probability of a pollution event may occur. The study area was the Derchi reservoir catchment in Taiwan. Pollution loads were derived from the AGNPS model with rainfall intensity estimated using the Thiessen method. Analyses for a network with various numbers of sampling sites were implemented. The results obtained based on varied cost factors were compared and discussed. With the three additional factors, the chosen sampling network is expected to properly detect pollution events and monitor pollution distribution and temporal trends.

Knee flexion after total knee arthroplasty

PURPOSE

To identify factors related to knee flexion after total knee arthroplasty in a Chinese population.

METHODS

Records of 242 total knee arthroplasties were retrospectively reviewed. The parameters evaluated were age, gender, diagnosis, preoperative knee flexion and extension, preoperative flexion arc, tibiofemoral angle, Knee Society knee score and functional score, and implant design.

RESULTS

Advanced age, female gender, and good preoperative flexion and flexion arc were related to better postoperative flexion. Postoperative flexion tended to migrate to the middle range despite different ranges of preoperative flexion. Preoperative tibiofemoral malalignment had no significant effect on postoperative flexion.

CONCLUSION

Contemporary designs of posterior stabilised prostheses with right and left femoral components were superior to older designs.

Synthesis of "cactus" top-decorated aligned carbon nanotubes and their third-order nonlinear optical properties

We report a new morphology of "cactus" top-decorated aligned carbon nanotubes grown by the PECVD method using pure C2H2 gas. Unlike most previous reports, no additional carrier gas is used for pretreatment. Carbon nanotubes can still grow and maintain the tubular structure underneath the "cactus" tops. It is proposed that the H atoms produced by the dissociation of C2H2 activate the catalyst nanoparticles. Scanning electron microscopy (SEM) shows that the top "cactus" morphology is composed of a large quantity of small nanosheets. Transmission electron microscopy (TEM) reveals the amorphous carbon nature of these "cactus" structures. The formation of these "cactus" structures is possibly due to covalent absorption and reconstruction of carbon atoms on the broken graphite layers of nanotubes produced by the strong ion bombardment under plasma. The third-order optical nonlinearities and nonlinear dynamics are also investigated. The third-order nonlinear susceptibility magnitude /chi(3)/ is found to be 2.2 x 10(-11) esu, and the relaxation process takes place in about 1.8 ps.

Epidemiology and cause of severe acute respiratory syndrome (SARS) in Guangdong, People's Republic of China, in February, 2003

BACKGROUND

An epidemic of severe acute respiratory syndrome (SARS) has been associated with an outbreak of atypical pneumonia originating in Guangdong Province, People's Republic of China. We aimed to identify the causative agent in the Guangdong outbreak and describe the emergence and spread of the disease within the province.

METHODS

We analysed epidemiological information and collected serum and nasopharyngeal aspirates from patients with SARS in Guangdong in mid-February, 2003. We did virus isolation, serological tests, and molecular assays to identify the causative agent.

FINDINGS

SARS had been circulating in other cities of Guangdong Province for about 2 months before causing a major outbreak in Guangzhou, the province's capital. A novel coronavirus, SARS coronavirus (CoV), was isolated from specimens from three patients with SARS. Viral antigens were also directly detected in nasopharyngeal aspirates from these patients. 48 of 55 (87%) patients had antibodies to SARS CoV in their convalescent sera. Genetic analysis showed that the SARS CoV isolates from Guangzhou shared the same origin with those in other countries, and had a phylogenetic pathway that matched the spread of SARS to the other parts of the world.

INTERPRETATION

SARS CoV is the infectious agent responsible for the epidemic outbreak of SARS in Guangdong. The virus isolated from patients in Guangdong is the prototype of the SARS CoV in other regions and countries.

Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China

A novel coronavirus (SCoV) is the etiological agent of severe acute respiratory syndrome (SARS). SCoV-like viruses were isolated from Himalayan palm civets found in a live-animal market in Guangdong, China. Evidence of virus infection was also detected in other animals (including a raccoon dog, Nyctereutes procyonoides) and in humans working at the same market. All the animal isolates retain a 29-nucleotide sequence that is not found in most human isolates. The detection of SCoV-like viruses in small, live wild mammals in a retail market indicates a route of interspecies transmission, although the natural reservoir is not known.

Expression of steroidogenic enzyme messenger ribonucleic acid and cortisol production in adrenocortical cells isolated from halothane-sensitive and halothane-resistant pigs

Stress susceptibility in pigs is inherited by a single recessive gene (Hal(n)), and homozygous individuals can be identified by exposure to halothane anesthesia. Previous studies have shown that in stress-susceptible pigs, exposure to a high ambient temperature resulted in a twofold increase in corticotropin (ACTH) and lower plasma cortisol. To determine whether there is a fundamental difference in adrenocortical function between halothane-sensitive (HAL-S) and halothane-resistant (HAL-R) pigs, independent of other factors influencing the hypothalamic-pituitary-adrenal (HPA) axis, we compared cortisol responses to ACTH and 8-bromo-cyclic AMP (8-Br-cAMP) in HAL-S and HAL-R pig adrenocortical cells in vitro. We also determined directly the accumulation of four different mRNAs encoding cholesterol side-chain cleavage cytochrome P450 (P450(scc)), 17alpha-hydroxylase cytochrome P450 (P450(17alpha)), 21-hydroxylase cytochrome P450 (P450(c21)) and 11beta-hydroxylase cytochrome P450 (P450(11beta)) in HAL-S pig adrenal cells and compared them to HAL-R pigs. A time- and dose-dependent increase in medium content of cortisol and cAMP was observed after ACTH treatment. 8-Br-cAMP also caused a time- and dose-dependent increase in cortisol production in the medium. Addition of ACTH or 8-Br-cAMP to HAL-S and HAL-R male Lanyu small-ear miniature pig adrenocortical cells increased cortisol production in a dose- and time-related manner. However, cells isolated from HAL-S pigs had a lower cortisol production in response to ACTH or 8-Br-cAMP compared to those from HAL-R pigs. Treatment of cultured cells with 8-Br-cAMP (0.5 mM) for 18 h resulted in a significant increase in P450(scc), P450(17alpha), P450(c21), and P450(11beta) mRNA levels. In the absence of 8-Br-cAMP, the four genes were expressed constitutively in both HAL-S and HAL-R pig adrenal cells. Densitometric scanning of the autoradiograph indicated that the relative amounts of P450(scc) and P450(17(alpha)) mRNAs in HAL-S pig adrenal cells were between 48% and 53% of those detected in HAL-R pig adrenal cells (P < 0.05). No difference in the amounts of P450(c21) and P450(11beta) was seen in HAL-S and HAL-R pig adrenal cells. Addition of 8-Br-cAMP (0.5 mM) resulted in a uniform increase in the levels of all four P450 mRNAs in both HAL-S and HAL-R pig adrenal cells. However, the amounts of P450(scc) mRNA in HAL-S pig adrenal cells were 67% (P < 0.05) of those measured in HAL-R pig adrenal cells, whereas the amounts of P450(17alpha ), P450(c21), and P450(11beta) mRNAs were similar in these cells. Our data suggest an HPA axis defect in HAL-S pigs at the adrenal level. This defect appears to be at the level of P450scc gene expression, which could be partially related to reduced cortisol production by ACTH stimulation.

An electron microscopic-cytochemical localization of plasma membrane Ca(2+)-ATPase activity in poplar apical bud cells during the induction of dormancy by short-day photoperiods

Plasma membrane (PM) Ca2+-ATPase activity in poplar apical bud meristematic cells during short-day (SD)-induced dormancy development was examined by a cerium precipitation EM-cytochemical method. Ca2+-ATPase activity, indicated by the status of cerium phosphate precipitated grains, was localized mainly on the interior face (cytoplasmic side) of the PM when plants were grown under long days and reached a deep dormancy. A few reaction products were also observed on the nuclear envelope. When plant buds were developing dormancy after 28 to 42 d of SD exposure, almost no reaction products were present on the interior face of the PM. In contrast, a large number of cerium phosphate precipitated grains were distributed on the exterior face of the PM. After 70 d of SD exposure, when buds had developed a deep dormancy, the reaction products of Ca2+-ATPase activity again appeared on the interior face of the PM. The results seemed suggesting that two kinds of Ca2+-ATPases may be present on the PM during the SD-induced dormancy in poplar. One is the Ca2+-pumping ATPase, which is located on the interior face of the PM, for maintaining and restoring the Ca2+ homeostasis. The other might be an ecto-Ca2+-ATPase, which is located on the exterior face of the PM, for the exocytosis of cell wall materials as suggested by the fact of the cell wall thickening during the dormancy development in poplar.

Guillain-Barré syndrome presenting with severe pain: report of one case

Most neurologists are familiar with pain in Guillain-Barré syndrome but some pediatricians may still miss or underestimate it. We report a 10-year-old girl who presented with headache and numbness in lower extremities. On examination, she could walk and showed hyporeflexia, mild muscle weakness, prominent neck rigidity and right facial nerve palsy. Headache and pain in neck, low back and calves were so severe that she could not fall asleep and the response to analgesic was very poor. On 8th day of illness, she needed mechanical ventilation and suffered tetraplegia. Symptoms of autonomic dysfunction including hypertension and sinus tachycardia appeared thereafter and lasted for a week. After receiving a high dose of intravenous immunoglobulin (2 g/kg in 2 days), her condition improved gradually although joint pain persisted for about three weeks. She could walk unaided by day 40 and run by day 70, and recovered completely 6 months later. We emphasize that pain in GBS needs proper evaluation and management in children as well as in adults.

Intermittent form of maple syrup urine disease: report of one case

We present a Chinese female infant with an intermittent form of MSUD whose early development was relatively well. A total of three episodes of stupor and metabolic acidosis developed with a concurrent illness after the age of 13 months. The initial analyses of plasma amino acid and urinary organic acid were normal. Initially, an abnormal oral glucose lactate stimulation test and high signal in the bilateral globus pallidus over T2-weighted brain MRI led us to suspect a mitochondrial disorder. The final diagnosis was made after the patient died at 31 months of age.

Corticotropin-releasing hormone stimulates the expression of the steroidogenic acute regulatory protein in MA-10 mouse cells

We have previously demonstrated that corticotropin-releasing hormone (CRH) treatment of MA-10 mouse Leydig tumor cells results in a dose-dependent stimulation of progesterone production. In view of this observation we wished to determine the effects of CRH on the synthesis of the steroidogenic acute regulatory (StAR) protein in these cells. StAR is a steroidogenic tissue-specific, hormone-induced, rapidly synthesized protein previously shown to be involved in the acute regulation of steroidogenesis, probably by promoting the transfer of cholesterol to the inner mitochondrial membrane and the cytochrome P450 side-chain cleavage enzyme. Treatment of MA-10 cells with the cAMP analogue dibutyryl cAMP (dbcAMP) resulted in a dose- and time-dependent increase in the levels of StAR protein that reached a maximum at 800 microM dbcAMP and within a time period of 6 h. Further, treatment of MA-10 cells with CRH also resulted in a dose-dependent increase in the synthesis of the StAR protein with a maximal response observed at 1 microM. Slightly different from that observed with dbcAMP, the maximal response to 1 microM CRH was seen at 4 h following stimulation. These results indicate that the observed increase in steroid production in response to CRH in MA-10 Leydig tumor cells is similar to that previously seen with trophic hormone stimulation acting through the cAMP second messenger pathway, and that it occurs as a result of an increase in the synthesis of the StAR protein.

Clinical analysis of 22 infants with afebrile cluster seizures

The inclusion criteria for afebrile cluster seizures in infancy are defined as follows: (1) frequency of afebrile seizures at least 2 episodes within 72 hours; (2) seizure onset between 2 months and 3 years of age; (3) excluding febrile convulsion, central nervous system infections, status epilepticus, well-known epileptic syndromes in infancy (e.g. early myoclonic encephalopathy, early infantile epileptic encephalopathy, benign myoclonic epilepsy, infantile spasms. Lennox-Gastaut syndrome), electrolyte imbalance, watery diarrhea, head injury and intoxication. From 1986 to 1996, retrospectively and prospectively 22 patients were collected who fulfilled the above criteria. Based on whether or not a strong family history was present and a history of mild diarrhea was associated with seizure onset, they were divided into three groups: Group I, benign infantile familial convulsions (4 patients); Group II, cluster seizures with mild diarrhea in infancy (5 patients); Group III, cluster seizures without diarrhea in infancy (13 patients). Before seizure onset and during follow-up, all of the patients had normal development. The seizure pattern in all was generalized, most tonic type with duration of seizure less than five minutes in the majority. Recurrence rate was 100% in Group I and no recurrence in Group II. In 16 patients who were seizure-free over 12 months, the duration of persistence varied from 1 day to 8 months, and was shortest in Group II (range, 1 to 3 days). It was concluded that the vast majority of afebrile cluster seizures in infancy are benign in nature. Whether anticonvulsant therapy is justified must be individualized.

Emergence of avian H1N1 influenza viruses in pigs in China

Avian influenza A viruses from Asia are recognized as the source of genes that reassorted with human viral genes to generate the Asian/57 (H2N2) and Hong Kong/68 (H3N2) pandemic strains earlier in this century. Here we report the genetic analysis of avian influenza A H1N1 viruses recently isolated from pigs in southern China, a host suspected to generate new pandemic strains through gene reassortment events. Each of the eight gene segments was of avian origin. Phylogenetic analysis indicates that these genes form an Asian sublineage of the Eurasian avian lineage, suggesting that these viruses are an independent introduction into pigs in Asia. The presence of avian influenza viruses in pigs in China places them in an optimal position for transmission to humans and may serve as an early warning of the emergence of the next human influenza virus pandemic.

Alagille syndrome with interstitial 20p deletion derived from maternal ins(7;20)

We present a 6-year-old Chinese boy with Alagille syndrome and an interstitial 20p deletion, with a karyotype of 46,XY,der(20)dir ins(7;20)(q11.23;p11.23p12.2 or p12.2p13)mat. He had a peculiar face and suffered from congenital heart disease, growth retardation, severe cholestasis, hepatosplenomegaly, and impaired renal function. The karyotype of his mother showed a balanced translocation, 46,XX,dir ins(7;20)(q11.23; p11.23p12.2 or p12.2p13), and her phenotype was normal. His dead elder brother was highly suspected as another victim of Alagille syndrome. The findings in the present family suggested that if Alagille syndrome is a single gene defect, the putative gene responsible for the syndrome would not be located at the insertion breakpoints but located within the deletion extent.

Analysis of late-blight disease resistance and freezing tolerance in transgenic potato plants expressing sense and antisense genes for an osmotin-like protein

The expression patterns of plant defense genes encoding osmotin and osmotin-like proteins imply a dual function in osmotic stress and plant pathogen defense. We have produced transgenic potato (Solanum commersonii Dun.) plants constitutively expressing sense or antisense RNAs from chimeric gene constructs consisting of the cauliflower mosaic virus 35S promoter and a cDNA (pA13) for an osmotin-like protein. Transgenic potato plants expressing high levels of the pA13 osmotin-like protein showed an increased tolerance to the late-blight fungus Phytophthora infestans at various phases of infection, with a greater resistance at an early phase of fungal infection. There was a decrease in the accumulation of osmotin-like mRNAs and proteins when antisense transformants were challenged by fungal infection, although the antisense transformants did not exhibit any alterations in disease susceptibility. Expression of pA13 sense and antisense RNAs had no effect on the development of freezing tolerance in transgenic plants when assayed under a variety of conditions including treatments with abscisic acid or low temperature. These results provide evidence of antifungal activity for a potato osmotin-like protein against the fungus P. infestans, but do not indicate that pA13 osmotin-like protein is a major determinant of freezing tolerance.

Activation of two osmotin-like protein genes by abiotic stimuli and fungal pathogen in transgenic potato plants

Osmotin-like proteins are encoded by at least six members of a multigene family in Solanum commersonii. A genomic clone (lambda pGEM2a-7) that contains two osmotin-like protein genes (OSML13 and OSML81) arranged in the same transcriptional orientation has been isolated. Restriction mapping and sequence analysis indicated that the two intronless genes correspond to the previously characterized pA13 and pA81 cDNAs. To study the transcriptional activation of OSML13 and OSML81 promoters, the 5' flanking DNA sequence (-1078 to +35 of OSML13 and -1054 to +41 of OSML81) was fused to the beta-glucoronidase (GUS) coding region, and the chimeric gene fusions were introduced into wild potato (S. commersonii) plants via Agrobacterium-mediated transformation. Analysis of the chimeric gene expression in transgenic potato plants showed that both 5' flanking DNA sequences are sufficient to impart GUS inducibility by abscisic acid, NaCl, salicylic acid, wounding, and fungal infection. Low temperature activated both chimeric genes only slightly. Infection with Phytophthora infestans resulted in strong GUS expression from both chimeric genes primarily in the sites of pathogen invasion, suggesting a limited diffusion of fungal infection-mediated signals. The expression patterns of both osmotin-like protein genes implicate their dual functions in osmotic stress and plant pathogen defense.

Outbreak of equine influenza among horses in Hong Kong during 1992

Equine-2 influenza virus A (H3N8) infection occurred among vaccinated thoroughbred horses in Hong Kong during November and December 1992. The outbreak was unique in that it occurred among a large population stabled under intensive conditions. It resulted in the postponement of seven race meetings over a period of 32 days. The outbreak originated after the importation of horses 25 to 32 days before any clinical signs were reported. Vaccination did not prevent 75 per cent of the population from becoming infected, and half the infected horses developed clinical signs. Vaccination did, however, contribute to reducing the morbidity and the severity and duration of the clinical signs.

Expression of three osmotin-like protein genes in response to osmotic stress and fungal infection in potato

We have characterized three cDNAs encoding osmotin-like proteins from potato (Solanum commersonii) cell cultures. These cDNAs (pA13, pA35, and pA81) have extensive nucleotide identity in the coding regions but low homology in the 3' non-coding sequences, and may encode three isoforms of potato pathogenesis-related (PR) type 5 proteins. Using gene-specific probes, RNA gel blot analyses showed constitutive accumulation of osmotin-like protein mRNAs in cell cultures, leaves, stems, roots and flowers, with high abundance in the roots and mature flowers. Treatments with abscisic acid (ABA), low temperature, and NaCl increased the accumulation of all three mRNAs in S. commersonii cell cultures and plants grown in vitro. Salicylic acid (SA), and wounding resulted in a moderate increase in the levels of pA13 and pA81 but not pA35 mRNAs. Infection with the fungus Phytophthora infestans activated strong and non-systemic expression of all three osmotin-like protein genes. The accumulation of osmotin-like proteins, however, was detected only in P. infestans-infected tissues but not in plants treated with ABA, SA, NaCl, low temperature, or wounding.

Rapid diagnosis of equine influenza by the Directigen FLU-A enzyme immunoassay

The Directigen FLU-A enzyme immunoassay was tested for its ability to detect equine-2 influenza viruses in nasopharyngeal fluids from horses and ponies. A total of 125 swabs from experimental infections and from different sources of natural infection in the USA and Hong Kong were examined. The assay results were compared with the results of standard virus culture in embryonated chicken eggs or Madin-Darby canine kidney cells, and with the serology of the horses sampled. In comparison with virus culture the enzyme immunoassay exhibited 83 per cent sensitivity, 78 per cent specificity, 70 per cent positive predictive value and 88 per cent negative predictive value. The test appeared to be more sensitive than haemagglutination for the detection of low levels of virus in embryonated egg cultures. It also detected equine-1 influenza virus in culture. The test is rapid (15 minutes), simple, and should be a convenient method for the rapid diagnosis and screening of horses for equine influenza infection.

The facilitatory effect of N-methyl-D-aspartate on sexual receptivity in female rats through GnRH release

The purpose of this study was to examine whether N-methyl-D-aspartate affects the sexual receptivity of female rats. Monosodium L-glutamate was used as a neurotoxin to induce hypogonadal status. Matured normal and monosodium L-glutamate-treated rats were ovariectomized and implanted subcutaneously with estradiol capsules. One week later, lordosis responsiveness was observed before and 10 min after N-methyl-D-aspartate (40 mg/kg of BW, ip) administration. The results showed that N-methyl-D-aspartate caused a remarkable increase of lordosis quotient in control rats but not in monosodium L-glutamate-treated rats. Moreover, the possible action site of N-methyl-D-aspartate in the enhancement of receptivity was evaluated by the post-castrational LH rise, pituitary LH release in response to GnRH, and N-methyl-D-aspartate-evoked GnRH releasability. The results revealed that: (a) serum levels of LH in monosodium L-glutamate-treated rats were lower (p < 0.01) than those of control rats after ovariectomy; (b) there was no significant difference of pituitary LH release responsiveness to GnRH test between two groups; and (c) N-methyl-D-aspartate-evoked LH release in monosodium L-glutamate-treated rats was similar to that in the control rats. In conclusion, N-methyl-D-aspartate may facilitate the sexual receptivity through stimulating GnRH release. The failure of N-methyl-D-aspartate in enhancing receptivity in monosodium L-glutamate-treated rats is probably due to the cellular damage by monosodium L-glutamate on specific areas responsible for lordosis.

Expression of an ABA-responsive osmotin-like gene during the induction of freezing tolerance in Solanum commersonii

We have isolated a cDNA (pA13) of an ABA-responsive gene from suspension cultures of Solanum cultures of Solanum commersonii. The deduced amino acid sequence of pA13 cDNA revealed 89 and 91% identity with tobacco osmotin and tomato NP24 protein, respectively. The accumulation of the transcript corresponding to pA13 cDNA was regulated by ABA, cold temperature, and low water potential treatments. Cold-induced accumulation of the pA13 transcript was partially suppressed by fluridone, an ABA synthesis inhibitor, and the suppression was restored by exogenous ABA application. The transcript corresponding to pA13 also accumulated in an organ-specific manner in response to ABA or cold treatment.

Actions of corticotropin-releasing factor or cortisol on follicle-stimulating hormone secretion by isolated pig pituitary cells

This study investigated the direct effects of hydrocortisone (HS), corticotropin-releasing factor (CRF), and adrenocorticotropin (ACTH) on basal and gonadotropin-releasing hormone (GnRH)-stimulated secretion of follicle-stimulating hormone (FSH) from dispersed pig pituitary cells in vitro. Pig pituitaries were dispersed into cells with collagenase, DNAase, and hyaluronidase and then cultured in McCoy's 5a medium containing horse serum (10%) and fetal calf serum (2.5%) pretreated with dextran-coated charcoal for 3 days. Cells were preincubated with steroids, CRF, or ACTH before GnRH was added. HS did not affect basal FSH secretion after 72 h of incubation. Treatment of pituitary cells with increasing concentrations (0.001-800 micrograms/ml) of HS for 72 h resulted in a dose-dependent decrease in GnRH-stimulated FSH release. HS pretreatment did not cause a change in cellular FSH content. Increasing duration (6-72 h) of treatment with HS (200 micrograms/ml) led to a time-dependent decrease in GnRH-stimulated FSH release, achieving statistical significance by 12 h. Porcine ACTH had no influence on basal and GnRH-stimulated FSH secretion. CRF decreased GnRH-stimulated FSH secretion in a dose-dependent manner, and the inhibitory effect required preincubation (6-18 h) with CRF. HS inhibited the FSH secretory responses to phospholipase C, melittin, and 8-bromo-cAMP but did not affect the response to 1,2-dioctanoyl-sn-glycerol and ionophore A23187. These results indicate that both cortisol and CRF can act directly on pig pituitary to inhibit FSH responsiveness to GnRH.

An enzyme-immunoassay of abscisic acid in potato (Solanum commersonii) cultured cells

Estimation of abscisic acid (ABA) content in potato (Solanum commersonii) suspension-cultured cells with an enzyme-immunoassay (EIA) was investigated. In crude extracts of potato cultured cells or even after simple clean-up using C18 cartridge, EIA based on commercial monoclonal antibodies (Idetek, Inc) failed to detect any ABA content. An interference could be removed by partitioning against ethyl acetate after the C18 cartridge so that the EIA yielded an estimate of ABA similar to that determined by high pressure liquid chromatography and gas chromatography-mass spectrometry analysis. These results demonstrate the presence of metabolites in potato cultured cell extract that prevent the binding of ABA to its binding site but not the binding of tracer.

Abscisic Acid-induced chilling tolerance in maize suspension-cultured cells

The induction of chilling tolerance by abscisic acid (ABA) in maize (Zea mays L. cv Black Mexican Sweet) suspension cultured cells was examined. Cell viability during exposure to chilling was estimated by triphenyl tetrazolium chloride reduction immediately after chilling and a filter paper growth assay. Both methods yielded comparable results. Chilling tolerance was induced by transferring 5-day-old cultures (late log phase) to a fresh medium containing ABA (10 to 100 micromolar). The greatest chilling tolerance was achieved with ABA at 100 micromolar. Growth of cells was inhibited at this concentration. After a 7-day exposure to 4 degrees C in the dark, the survival of ABA-treated cells (100 micromolar ABA, 28 degrees C for 24 h in the dark) was sevenfold greater than untreated cells. Effective induction of chilling tolerance was first observed when cells were held at 28 degrees C for 6 hours after adding ABA. No tolerance was induced if the culture was chilled at the inception of ABA treatment. Induction of chilling tolerance was inhibited by cycloheximide. These results indicate that ABA is capable of inducing chilling tolerance when ABA-treated cells are incubated at a warm temperature before exposure to chilling, and this induction requires de novo synthesis of proteins.

Catecholamine inhibition of luteinizing hormone secretion in isolated pig pituitary cells

This study investigated the direct effect of catecholamines, epinephrine (EPI), and norepinephrine (NE) on basal and gonadotropin-releasing hormone (GnRH)-stimulated secretion of luteinizing hormone (LH) from dispersed pig pituitary cells in vitro. Pig pituitaries were dispersed into cells with collagenase and DNAase and then cultured in McCoy's 5a medium containing horse serum (10%) and fetal calf serum (2.5%) pretreated with dextran-coated charcoal for 3 days. EPI and NE did not affect basal LH secretion after 4 h of incubation. When pituitary cells were incubated with EPI or NE (1 microgram/ml) for longer than 30 min, GnRH-stimulated LH secretion was reduced. The degree of this reduction was dependent on EPI and NE, and a concentration of EPI and NE higher than 1 ng/ml and 100 ng/ml, respectively, was needed. L-isoproterenol, a nonselective beta-agonist, also inhibited the LH response to GnRH. Propranolol, a beta-antagonist, blocked the inhibitory effect of EPI, whereas phentolamine, an alpha-antagonist, had no effect. These results suggest that catecholamines, acting by a beta 2-adrenergic receptor, may play a role in the control of the porcine pituitary gonadotrope's response to GnRH.

Effect of cortisol or adrenocorticotropic hormone on luteinizing hormone secretion by pig pituitary cells in vitro

The effect of cortisol or adrenocorticotropic hormone (ACTH) on basal and gonadotropin-releasing hormone (GnRH)-induced secretion of luteinizing hormone (LH) was studied in vitro using dispersed pig pituitary cells. Pig pituitary cells were dispersed with collagenase and DNAase and then grown in McCoy's 5a medium containing 10% dextran charcoal-pretreated horse serum and 2.5% fetal calf serum for 3 days. Cells were preincubated with cortisol or ACTH before GnRH was added. When pituitary cells were incubated with 400 micrograms cortisol/ml medium for 6 h or longer, increase basal secretion of LH was observed. However, GnRH-induced LH release was reduced by cortisol. The degree of this reduction was dependent on cortisol, and a concentration of cortisol higher than 100 micrograms/ml was needed. Cortisol also inhibited the 17 beta-estradiol-induced increase in GnRH response. ACTH-(1-24), ACTH-(1-39), or porcine ACTH had no influence on GnRH-induced LH secretion. Our results show that cortisol can act directly on pig pituitary to inhibit both normal and estradiol-sensitized LH responsiveness to GnRH.

Effect of 3-hydroxy-4-1(H)pyridone on the basal and thyrotropin-releasing hormone-stimulated release of thyroid-stimulating hormone from perifused anterior pituitary fragments

This study investigated the direct effect of 3-hydroxy-4-1(H)-pyridone (DHP), the breakdown product of mimosine in the rumen, on thyroid-stimulating hormone (TSH) secretion by perifusion of rat anterior pituitary fragments. During a 2-h perifusion with thyrotropin-releasing hormone (TRH), the total release of TSH increased linearly (P less than 0.05, r = 0.966) with increasing concentration of TRH from 1 to 100 ng/ml. The release was maximal at 100 ng/ml. There were no differences in total basal TSH release among control and DHP-treated pituitary fragments. DHP at concentrations of 1, 10, and 100 micrograms/ml had no significant effect on the TSH response to TRH. However, DHP at the concentration of 1 mg/ml significantly suppressed the TSH response to TRH administered continuously or as a 10-min pulse. These results suggest that DHP modulates the pituitary thyrotroph's response to TRH.