[Exploration of construction mode of real-world data system]

Real-world data study evidence, as an important part of evaluating the safety and effectiveness of drugs and devices, has attracted increasing attention from regulatory agencies and scholars both at home and abroad, and has become an essential source of evidence to support the development and review of drugs and devices. This paper systematically discusses the process and mode of real-world data system construction based on the preliminary practical study of real-world data according to the guidelines/technical specifications issued by regulatory agencies and academic research results. This study result provides not only reference for the generation of clinical evaluation evidence to meet the regulatory requirements for innovative drugs and devices, but also reference for researchers, sponsors and regulators to carry out real-world data studies successfully.

[Real-world data studies of medical products in the context of special healthcare policy: study designs and key considerations]

Boao Lecheng International Medical Tourism Pilot Area is the only administrative area in China where the pilot application of real-world data is performed. Based on the special healthcare policy in Boao Lecheng, conducting real-world data study to provide real-world evidence for the clinical evaluations and approvals of innovated medical products has become an important field that supports the reform of China's evaluation and approval system of medical products. Trustworthy real-world evidence needs to rely on both high-quality real-world data and reasonable and rigorous study designs. Based on the real-world data research guidelines and specifications issued by relevant academic research and regulatory authorities both at home and abroad, combined with the special policy environment of Boao Lecheng and previous practice experience, this paper summarizes the study designs of real world data in Boao Lecheng and discusses the key considerations of different study design in the context of special healthcare policies in Boao Lecheng in order to provide reference for the further study of real-world data.

[Surgical treatment of tricuspid valve disease due to permanent pacemaker lead]

Objective: To summarize the etiology and surgical treatment experience of tricuspid valve disease due to permanent pacemaker lead. Methods: The medical records of 22 patients who underwent tricuspid valve operation for tricuspid valve disease due to permanent cardiac pacemaker lead from January 2008 to December 2017 were retrospectively reviewed. There were 12 males and 10 females, with a mean age of (62.6±12.1) years old (45-82 years old). All patients underwent tricuspid valve surgery via open thoracotomy under general anesthesia, including 8 patients through median thoracotomy approach, 4 patients through right mini-thoracotomy approach, and 10 patients with endoscopy-assisted and totally endoscopic technique. Moreover, 8 patients underwent tricuspid valve replacement, and 14 patients received tricuspid valve repair. Results: During the operation, 10 cases of severe tricuspid regurgitation were detected due to valve and subvalvular structures dysfunction involved in the pacing electrode, 7 cases showed tricuspid annulus dilation, and pacing electrode-related infective endocarditis were involved in the tricuspid valve of 5 cases. Compared with conventional median thoracotomy surgery, the amount of postoperative drainage fluid and hospitalization time after minimally invasive surgery (including right mini-thoracotomy and endoscopic surgery) were significantly reduced [281(120, 489) ml vs 368(180, 560) ml, P=0.02; 9.2(4.8, 14.5) d vs 11.2(6.3, 16.9) d, P=0.03]. Postoperative echocardiographic data showed that the size of the right atrium and ventricle in these patients was significantly reduced compared with preoperative data, and their cardiac function were normal. There was no difference of pacing electrode parameters between pre-and postoperative period. All 22 patients were cured and discharged, with no valve-and pacemaker-related complications. Conclusions: Patients with tricuspid valve disease due to permanent cardiac pacemaker lead should actively undergo surgery including tricuspid replacement or repair according to different etiologies, which exhibit satisfactory outcomes. Minimally invasive endoscopic tricuspid surgery is a new technique for the treatment of isolated tricuspid valve disease, with less surgical trauma and faster recovery.

[Assessment of mortality burden and economic loss attributed to long-term PM(2.5) exposure in the Beijing-Tianjin-Hebei area]

Objective: To accurately estimate the health burden and corresponding economic loss attributed to PM(2.5) pollution in the Beijing-Tianjin-Hebei (BTH) area in China in 2015. Method: By using satellite-retrieved PM(2.5) concentration data and population data provided by NASA (the spatial resolution was 1 km×1 km), this study estimated excess mortality attributed to long-term PM(2).5 exposure in BTH area in 2015 based on Global Exposure Mortality Model (GEMM). Besides, Value of Statistic Life (VSL) method was used to evaluate the corresponding health economic loss. Result: In BTH area, the population-weighted average PM(2.5) concentration during 2012-2014 was 46.25 μg/m(3), and 56.6% of total population lived in the area where annual average PM(2.5) concentration exceeded Grade Ⅱ of National Ambient Air Quality Standard in China (35 μg/m(3)); The PM(2.5)-related premature deaths amounted to 193.8 thousand (95%CI: 140.9 thousand-233.3 thousand), Beijing, Tianjin, Baoding, Shijiazhuang, and Handan were the top five cities with high incidences of PM(2.5)-related premature deaths; The corresponding health economic loss was about 35.934 billion (95%CI: 26.099 billion - 43.255 billion) RMB, accounting for 0.70% (95%CI: 0.51%-0.85%) of the area's GDP in 2015, Beijing, Tianjin, Baoding, Shijiazhuang, and Cangzhou were the top five cities with high health economic loss. Conclusions: PM(2.5) pollution has caused severe disease and economic burden in BTH area. Its spatial distribution suggested that it is particularly necessary to develop the air pollution prevention and control policies for key cities.

Clinical course of suspected small gastrointestinal stromal tumors in the stomach

BACKGROUND

Gastric subepithelial lesions are frequently encountered during endoscopic examinations, and the majority of them are small and asymptomatic. Among these lesions, gastrointestinal stromal tumors (GISTs) are the major concern for patients and clinicians owing to their malignant potentials. Although previous guidelines suggested periodic surveillance for such small (≤ 20 mm) lesions, several patients and clinicians have still requested or prescribed repeated examinations or radical resection, posing extra medical burdens and risks.

AIM

To describe the clinical course of suspected small gastric GISTs and provide further evidence for surveillance strategy for tumor therapy.

METHODS

This single-center, retrospective study was conducted at West China Hospital, Sichuan University. Consecutive patients with suspected small gastric GISTs were reviewed from November 2004 to November 2018. GIST was suspected according to endoscopic ultrasonography features: hypoechoic lesions from muscularis propria or muscularis mucosa. Eligible patients with suspected small (≤ 20 mm) GISTs were included for analysis. Patients’ demographic data, lesions’ characteristics, and follow-up medical records were collected.

RESULTS

A total of 383 patients (male/female, 121/262; mean age, 54 years) with 410 suspected small gastric GISTs (1 lesion in 362 patients, 2 lesions in 16, 3 lesions in 4, and 4 lesions in 1) were included for analysis. The most common location was gastric fundus (56.6%), followed by body (29.0%), cardia (12.2%), and antrum (2.2%). After a median follow-up of 28 mo (interquartile range, 16-48; range, 3-156), 402 lesions (98.0%) showed no changes in size, and size of 8 lesions (2.0%) was increased (mean increment, 10 mm). Of the 8 lesions with size increment, endoscopic or surgical resection was performed in 6 patients (5 GISTs and 1 leiomyoma). For other 2 remaining patients, unroofing biopsy or endoscopic ultrasound-guided fine-needle aspiration was carried out (2 GISTs), while no further change in size was noted over a period of 62-64 mo.

CONCLUSION

The majority of suspected small (≤ 20 mm) gastric GISTs had no size increment during follow-up. Regular endoscopic follow-up without pathological diagnosis may be highly helpful for such small gastric subepithelial lesions.

Biliary spontaneous dislodgement spiral stent for patients who underwent mechanical lithotripsy

BACKGROUND

The incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis (PEC) in patients who underwent mechanical lithotripsy (ML) for large stone removal is high (up to 13.3%). One of the main causes is remaining small fragments or sludge that can impair normal biliary drainage. Endoscopic placement of a nasobiliary tube or a conventional plastic biliary stent has been commonly used under such conditions, but the patient may suffer from significant discomfort after the placement of a nasobiliary tube, while additional endoscopy is required for stent removal. We developed a biliary spontaneous dislodgement spiral stent (BSDSS) to overcome those shortcomings.

AIM

To evaluate the feasibility, safety, and effectiveness of inserting a BSDSS for patients who underwent ML for large stone removal.

METHODS

We conducted a single-center, retrospective, cohort study at West China Hospital, Sichuan University. A total of 91 consecutive patients with large biliary stones (≥ 10 mm) in the common bile duct who underwent ML between November 2017 and July 2018 were included. The 49 eligible patients were divided into the BSDSS group and the nasobiliary tube group. Technical success, post-ERCP adverse events (including PEC, post-ERCP pancreatitis, stone recurrence, BSDSS retention, self-extraction and dislocation of the nasobiliary tube), drainage time, and postoperative stay were measured and compared.

RESULTS

Twenty-one patients in the BSDSS group and 28 patients in the nasobiliary tube group were included in the analyses. The baseline characteristics and clinical information were similar in the two groups. Insertions of BSDSS and nasobiliary tube were technically successful in all 49 patients. There was no significant difference in the incidence of overall post-ERCP adverse events between the two groups (4.8% in the BSDSS group vs 17.9% in the nasobiliary tube group, P = 0.219). The median duration of drainage time (3 d in the BSDSS group vs 4 d in the nasobiliary tube group) and length of postoperative stay (4 d in the BSDSS group vs 5 d in the nasobiliary tube group) also did not differ (P = 0.934, and P = 0.223, respectively).

CONCLUSION

Endoscopic placement of a BSDSS appears to be feasible, safe and effective for patients who underwent ML for large stone removal.

Expression and prognostic significance of melatonin receptor MT1 in patients with gastric adenocarcinoma

Melatonin receptor type 1 (MTNR1A or MT1) is known to play an important role in cancer progression; however, its prognostic value for resected gastric adenocarcinoma (RGA) is unknown. In this study, we examined the potential of MT1 as a prognostic biomarker for RGA. The expression of the MT1 was evaluated in 67 patients with RGA by immunohistochemistry, and the relationship between MT1 levels and RGA prognosis was analyzed by Chi-square test, multivariate Cox regression, Kaplan-Meier method, and log-rank test. High MT1 expression was associated with a poor survival rate (29.0%, p=0.002) and the occurrence of metastasis (62.9%, p=0.004). Kaplan-Meier survival analysis and log rank tests revealed that patients with high expression of the MT1 had significantly shorter median overall survival compared to those with low expression (33.0 vs. 65.0 months, respectively; p=0.02). Multivariate Cox analysis indicated that the calculated death risk (hazard ratio [HR]) in patients with high expression levels of the MT1 increased to 2.68 (95% confidence interval [CI] 1.21-5.94, p=0.015), which was higher compared to those with low levels. HR of death was also high in patients with advanced T stage (2.51; 95 % CI 1.00-6.26, p=0.049) and metastasis (5.02; 95% CI 1.94-13.03, p=0.001). Our results showed that high MT1 expression in primary gastric adenocarcinoma tissues was associated with the occurrence of metastasis and poor prognosis. It may have prognostic significance as a potential biomarker in patients with RGA.

All-cause child mortality in minority and non-minority areas in Sichuan Province in Western China, 2008-2017

This study aimed to evaluate the disparity in the under-five mortality rate (U5MR) between minority and non-minority areas in Sichuan Province in Western China. Data for this study was obtained from the National Health Statistics Survey System. The Cochran-Armitage trend test was used to analyze the time trend of the U5MR. We conducted Poisson regression model to compare the differences of U5MRs between minority and non-minority areas. The U5MR in Sichuan province was reduced by 62.19% from 2008 to 2017, with the minority and non-minority areas reduced by 60.48% and 65.39%, respectively. The under-five mortality risk in minority areas was approximately 1.791 times (95% CI: 1.790–1.793; P < 0.01) that in non-minority areas. The primary cause of death of children under-five years old in minority areas was the respiratory disease, which was significantly higher than that in non-minority areas (P all < 0.01). The U5MR significantly declined both in minority and non-minority areas in Sichuan Province in Western China from 2008 to 2017. However, disparities still existed between minority and non-minority areas. Respiratory diseases were the main causes of death in minority areas and corresponding rates were higher than those in non-minority areas.

New antireflux plastic stent for patients with distal malignant biliary obstruction

BACKGROUND

Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction (MBO). However, the main problem with stent placement is the relatively short duration of stent patency. Although self-expanding metal stents (SEMSs) have a longer patency period than plastic stents (PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS (ARPS) has been proposed. We developed a new ARPS with a “duckbilled” valve attached to the duodenal end of the stent.

AIM

To compare the patency of ARPSs with that of traditional PSs (TPSs) in patients with unresectable distal MBO.

METHODS

We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success, adverse events, and patient survival.

RESULTS

Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events (P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range (IQR), 170], which was significantly longer than that in the TPS group (median, 130 d; IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups (P = 0.900).

CONCLUSION

The new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency than a TPS.

Association between Polymorphisms and Haplotype in the ABCA1 Gene and Overweight/Obesity Patients in the Uyghur Population of China

OBJECTIVE

This study aimed to detect the association between polymorphisms and haplotype in the ATP-binding cassette transporter A1 (ABCA1) gene and overweight/obese Uyghur patients in China.

METHODS

A total of 259 overweight/obese patients and 276 normal weight subjects, which were randomly selected from among 3049 adult Uyghurs, were matched for age. We genotyped ABCA1 single nucleotide polymorphisms of rs2515602, rs3890182, rs2275542, rs2230806, rs1800976, and rs4149313.

RESULTS

(1) The genotypic and allelic frequencies of rs2515602 and rs4149313 differed between the control group and case group. The genotypic frequency of rs2275542 also differed between the control group and case group (p < 0.05); (2) rs2515602, rs2230806, and rs4149313 polymorphisms were significantly related to risk of overweight/obese; (3) a significant linkage disequilibrium (LD) was observed between the ABCA1 gene rs2275542 with rs3890182 and rs2515602 with rs4149313. (4) the C-C-C-A-G-G, T-C-G-A-G-G, and T-T-G-G-G-A haplotypes were significant in normal weight and overweight/obese subjects (p < 0.05); (5) the levels of HDL-C (rs2515602, rs2275542, rs4149313) in normal weight subjects were different among the genotypes (p < 0.05); the levels of TC, LDL-C and TG (rs1800976) in overweight/obese subjects were different among the genotypes (p < 0.05).

CONCLUSIONS

The rs2515602, rs4149313, and rs2275542 polymorphisms were associated with overweight/obese conditions among Uyghurs. Strong LD was noted between rs2275542 with rs3890182 and rs2515602 with rs4149313. The C-C-C-A-G-G and T-C-G-A-G-G haplotypes may serve as risk factors of overweight/obesity among Uyghurs. The T-T-G-G-G-A haplotype may serve as a protective factor of overweight/obesity among Uyghurs. Rs2515602, rs2275542, rs4149313, and rs1800976 polymorphisms in the ABCA1 gene may influence lipid profiles.

Epidemiological characteristics of malaria in Ningbo City, China 2000-2011

The objective of this study was to explore the trend and the epidemiological characteristics of malaria in Ningbo from 2000 through 2011 and provide scientific evidence for the prevention and control. Using the retrospective study, data relating to malaria epidemics during 2000-2011 in Ningbo were collected through the questionnaires of the cases and other important surveillance data. Adult mosquitoes were collected using CDC light traps baited with CO2. Results showed that Plasmodium vivax was the main species, and Anopheles sinensis was the only vector species of malaria. The annual incidence rates (per 100000) ranged from 0.156 to 3.224, and about 95.41% of the cases were imported. The cases occurred mainly between May and November and the incidence showed two peaks, and the local transmission of malaria was determined by vector density. Considering the vast majority of these infections were imported vivax malaria cases from domestic endemic areas (particularly Anhui province), and may lead to limited local transmission, strengthening the routine monitoring of imported malaria, ensuring timely diagnosis, improving case detection rate, giving a standardized treatment to patients and intensifying public health education on malaria prevention are extremely important to malaria prevention and control activities.

Modafinil exerts a dose-dependent antiepileptic effect mediated by adrenergic α1 and histaminergic H1 receptors in mice

Epilepsy is characterized by neuronal hyperexcitability and hypersynchronization. Disruption of electroencephalographically (EEG) synchronized epileptiform discharges may be a possible therapy for epilepsy. In the present study, to clarify the role of EEG desynchronization on epilepsy, we investigated the effect of modafinil, a potent wake-promoting substance with EEG desynchronization activity, on epilepsy in mice and clarified the receptors involved in the suppression of seizure caused by maximal electroshock (MES) and pentylenetetrazol (PTZ) kindling models. Modafinil given at 22.5, 45, and 90 mg/kg, i.p. significantly decreased the incidence of tonic hindleg extension in MES seizure models, and protected against PTZ-induced convulsive behaviors in a dose-dependent manner. In addition, modafinil at 180 mg/kg exerted an antiepileptic effect in the MES model; however, at the same dosage it increased the seizure stage in the PTZ-kindling model. The antiepileptic effect in both MES and PTZ models was antagonized by the adrenergic alpha(1) receptor antagonist terazosin, but not by the adrenergic alpha(2) receptor antagonist yohimbine or by dopaminergic receptor antagonists, SCH-23390 (for D(1) receptors) and haloperidol (for D(2) ones). Pyrilamine, a histaminergic H(1) receptor antagonist, counteracted the antiepileptic action of modafinil in the PTZ induced-kindling model, but not in the MES seizure model. Taken together, the present findings indicate that modafinil exerted its antiepileptic effect via adrenergic alpha(1) and histaminergic H(1) receptors, and might be of potential use in the treatment of epilepsy.

Complex segregation analysis of nasopharyngeal carcinoma in Guangdong, China: evidence for a multifactorial mode of inheritance (complex segregation analysis of NPC in China)

The striking geographical and ethnic distribution of nasopharyngeal carcinoma (NPC) suggests the involvement of genetic and environmental factors in NPC development. The purpose of this study is to investigate the fit of single gene, polygenic and multifactorial models to the observed pattern of transmission of NPC in a hospital-based family history study conducted by the Cancer Center of Sun Yat-Sen University (CCSYU) in Guangzhou, China. Complex segregation analysis of a total of 1903 Cantonese pedigrees ascertained at CCSYU was conducted using a unified mixed model after the pedigrees were partitioned into 3737 nuclear families. The mixed model assumes that a phenotype is influenced by the additive and independent effect of a major gene, together with multifactorial components (genetic and environmental) and a random environmental effect. The current results do not provide evidence for a major gene and the observed data are best explained by a multifactorial mode of inheritance for NPC.

Familial risk and clustering of nasopharyngeal carcinoma in Guangdong, China

BACKGROUND

Previous studies have suggested that genetic susceptibility may play an important role in the etiology of nasopharyngeal cancer (NPC). However, to date, few large-scale studies have been conducted on familial risk and clustering of NPC in a high-risk area of China.

METHODS

In the current study, 2252 patients with NPC who were treated at the Cancer Center of Sun Yat-Sen University in Guangdong Province, China, were identified as probands. Family histories of NPC and other malignancies were observed in first-degree relatives (FDRs) and second-degree relatives, and other information was obtained through interviews. One thousand nine hundred and three Cantonese families were selected for further investigation. To assess familial aggregation, the authors used standardized incidence ratios (SIRs) to measure the risk of NPC for FDRs and compared the observed number of cases with the number predicted by population-based frequencies in the Cantonese population of Hong Kong.

RESULTS

The current analysis indicated that families with > or = 3 relatives who had NPC were distributed predominantly among a high-risk subgroup of the Cantonese population in Guangdong Province and that the frequency of these families was 0.68%. An SIR of 2.09 (95% confidence interval [CI], 1.80-2.40) was observed among 13,833 FDRs in the high-risk subgroup, and a significantly elevated risk for NPC was observed in FDRs of probands with early age of onset (age < 40 years; SIR, 9.01 [95% CI, 6.10-13.30]). Furthermore, decreased risks of hepatic, lung, esophageal, gastric, and breast carcinoma, as well as malignancy of all sites, were observed among FDRs of probands with NPC when Hong Kong and Shanghai populations were used as reference groups.

CONCLUSIONS

NPC tends to aggregate in Cantonese families in Guangdong Province, and the malignancies in these families appear to be site specific, with no excess of any other malignancy.

[Studies on mutation of isoniazid resistant genes in M. tuberculosis]

OBJECTIVE

To understand mutation of isoniazid-resistant genes in M. tuberculosis clinical isolates, and to develop the method for rapid detection of drug resistance.

METHOD

Analyzing the katG genes in 30 M. tuberculosis clinical isolates with PCR-SSCP(single stranded conformation polymorphism) and PCR-DS (direct sequencing) techinques.

RESULTS

With the reference of M. tuberculosis strain H37 Rv was used as control, all isoniazid-sensitive isolates and 4 isoniazid-resistant isolates displayed ab normal PCR-SSCP and PCR-DS patterns. But of 12 isoniazid-resistant isolates, 4(33.4%) isolates displayed abnormal katG PCR-SSCP pattern, 8 (46.7%) isolates displayed abnormal katG PCR-SSCP pattern, 5(41.7%) isolates were missense mutation at codon 94, 3(25%) isolates were cosense mutation at codon 96.

CONCLUSIONS

Resistance to isoniazid in most M. tuberculosis isolates is due to the mutations on katG genes. PCR-SSCP techniques could be used as a method for rapid detection of isoniazid-resistance in M. tuberculosis.

Effects of toquipidine on ionic channels of cultured embryonic Xenopus laevis myoblasts and neurons

AIM

To study the effects of toquipidine (1-p-methyl-phenyl-2-(alpha-piperidinoacetyl)-1, 2, 3, 4-tetrahydroisoquinoline hydrochloride, Toq), a new anti-arrhythmic agent first synthesized in China, on ionic channels.

METHODS

Ionic channel currents were recorded by whole-cell patch clamp technique in cultured embryonic Xenopus laevis myoblasts and neurons.

RESULTS

Toq (0.1, 1, 10, and 100 mumol L-1) caused a concentration-dependent inhibition of the Na+ currents with IC50 7.2 mumol L-1 (5.3-9.8 mumol L-1). Toq (10 mumol L-1) also suppressed the high-voltage-activated Ca2+ currents in neurons. But the steady-state outward K+ currents in myoblasts were activated by Toq (10 mumol L-1).

CONCLUSION

Toq blocked the Na+ and Ca2+ channels and opened the steady-state outward K+ channels.

Effects of nimodipine, felodipine, and verapamil on isolated human arteries

AIM

To evaluate whether there might be some difference in the action modes of nimodipine (Nim) and felodipine (Fel).

METHODS

Compare the inhibitory effects of Nim and Fel with that of verapamil (Ver) as a representative of phenylalklamine on norepinephrine (NE)- and CaCl2-evoked contractions of human arteries.

RESULTS

In Ca(2+)-free and high K+ depolarized solution, inhibitory effects of Nim, Fel, and Ver were more potent on CaCl2-induced contractions on isolated human arteries than those on NE-induced contractions. In CaCl2-induced contraction, the pD2 values for Nim, Fel, and Ver were 7.5, 7.42, 6.35 on uterine arteries; 7.38, 7.65, 7.20 on mesenteric arteries and 7.87, 9.10, 7.32 on renal arteries, respectively. Ver inhibited 2 components of NE-evoked contraction, while Nim and Fel only inhibited extracellular Ca(2+)-dependent contractions.

CONCLUSION

The result indicates that Fel has a selective action on human renal arteries.

Study on the mechanism of interferon action (XI)--Effect of pppA2'p5'A on the level of cAMP and cGMP in macrophages

In this paper, the increase of cellular cAMP and cGMP levels in macrophages induced by ppA2'p5' A2'p5'A (briefly 2'-5'P3A3) is first reported. The optimal concentration of 2'-5' P3A3 for the elevation of cellular cGMP to the highest level is 10(-7)-10(-6) mol/L, while that for cAMP is 10(-7) mol/L. The time for cGMP to reach its peak value is 15 min and that for cAMP is 2 h, when the cells are treated with 2'-5' P3A3 at 10(-7) mol/L, which is the optimal concentration for developing biological effect of macrophages (phagocytosis). These results suggest that cGMP and cAMP may be related to, or may be the mediators for, 2'-5'P3A3 action.