Use of artificial intelligence in the management of T1 colorectal cancer: a new tool in the arsenal or is deep learning out of its depth?

The field of artificial intelligence is rapidly evolving, and there has been an interest in its use to predict the risk of lymph node metastasis in T1 colorectal cancer. Accurately predicting lymph node invasion may result in fewer patients undergoing unnecessary surgeries; conversely, inadequate assessments will result in suboptimal oncological outcomes. This narrative review aims to summarize the current literature on deep learning for predicting the probability of lymph node metastasis in T1 colorectal cancer, highlighting areas of potential application and barriers that may limit its generalizability and clinical utility.

Real-World Validation of a Computer-Aided Diagnosis System for Prediction of Polyp Histology in Colonoscopy: A Prospective Multicenter Study

INTRODUCTION

Computer-aided diagnosis (CADx) of polyp histology could support endoscopists in clinical decision-making. However, this has not been validated in a real-world setting.

METHODS

We performed a prospective, multicenter study comparing CADx and endoscopist predictions of polyp histology in real-time colonoscopy. Optical diagnosis based on visual inspection of polyps was made by experienced endoscopists. After this, the automated output from the CADx support tool was recorded. All imaged polyps were resected for histological assessment. Primary outcome was difference in diagnostic performance between CADx and endoscopist prediction of polyp histology. Subgroup analysis was performed for polyp size, bowel preparation, difficulty of location of the polyps, and endoscopist experience.

RESULTS

A total of 661 eligible polyps were resected in 320 patients aged ≥40 years between March 2021 and July 2022. CADx had an overall accuracy of 71.6% (95% confidence interval [CI] 68.0-75.0), compared with 75.2% (95% CI 71.7-78.4) for endoscopists ( P = 0.023). The sensitivity of CADx for neoplastic polyps was 61.8% (95% CI 56.9-66.5), compared with 70.3% (95% CI 65.7-74.7) for endoscopists ( P < 0.001). The interobserver agreement between CADx and endoscopist predictions of polyp histology was moderate (83.1% agreement, κ 0.661). When there was concordance between CADx and endoscopist predictions, the accuracy increased to 78.1%.

DISCUSSION

The overall diagnostic accuracy and sensitivity for neoplastic polyps was higher in experienced endoscopists compared with CADx predictions, with moderate interobserver agreement. Concordance in predictions increased this diagnostic accuracy. Further research is required to improve the performance of CADx and to establish its role in clinical practice.

Clinical trial: seven-day vonoprazan- versus 14-day proton pump inhibitor-based triple therapy for first-line Helicobacter pylori eradication

BACKGROUND

One-week triple therapy with vonoprazan is endorsed by Japanese guidelines as an alternative to proton pump inhibitor (PPI)-based triple therapy for first-line Helicobacter pylori eradication. This contrasts with Western guidelines recommending 2-week PPI-based triple therapy.

AIM

To verify the non-inferiority of 1-week vonoprazan-based triple therapy versus 2-week PPI-based triple therapy as first-line H. pylori eradication in a multiracial Asian cohort.

METHODS

Randomised controlled trial of treatment-naïve patients with H. pylori infection assigned 1:1 to either 7 days amoxicillin 1 g + clarithromycin 500 mg + vonoprazan 20 mg twice per day or 14 days amoxicillin 1 g + clarithromycin 500 mg + omeprazole OR esomeprazole OR rabeprazole 20 mg twice/day. Subjects were randomly assigned to each PPI 1:1:1 Demographics, H. pylori resistance, CYP 2C19 genotype, eradication success and safety profiles were compared between groups.

RESULTS

Between June 2019 and June 2021, 252 of 1097 subjects screened were randomised. 244 (age [SD] 51.7 [14.6]) received vonoprazan- (n = 119) or PPI-based (n = 125) triple therapy. Eradication rates by intention-to-treat analysis were 87.4% (vonoprazan-based triple therapy) versus 88.0% (PPI-based triple therapy. By per protocol analysis: 96.3% (vonoprazan-based triple therapy) versus 94.0% (PPI-based triple therapy). Clarithromycin resistance predicted treatment failure on multivariate analysis: RR 11.4; 95% CI [1.4-96.3], p = 0.025. No significant differences in CYP 2C19 genotypes or adverse events occurred between groups.

CONCLUSION

One-week vonoprazan-based triple therapy achieved comparable efficacy to 2-week PPI-based triple therapy and was well tolerated.

Role of artificial intelligence in early detection and screening for pancreatic adenocarcinoma

Pancreatic adenocarcinoma remains to be one of the deadliest malignancies in the world despite treatment advancement over the past few decades. Its low survival rates and poor prognosis can be attributed to ambiguity in recommendations for screening and late symptom onset, contributing to its late presentation. In the recent years, artificial intelligence (AI) as emerged as a field to aid in the process of clinical decision making. Considerable efforts have been made in the realm of AI to screen for and predict future development of pancreatic ductal adenocarcinoma. This review discusses the use of AI in early detection and screening for pancreatic adenocarcinoma, and factors which may limit its use in a clinical setting.

Short- and long-term predictors of spontaneous bacterial peritonitis in Singapore

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is the commonest complication of liver cirrhosis. Timely and appropriate treatment of SBP is crucial, particularly with the rising worldwide prevalence of multidrug-resistant organisms (MDROs). We aimed to investigate the clinical outcomes of SBP in Singapore.

METHODS

All cirrhotic patients with SBP diagnosed between January 2014 and December 2017 were included. Nosocomial SBP (N-SBP) was defined as SBP diagnosed more than 48 hours after hospitalisation. Clinical outcomes were analysed as categorical outcomes using univariate and multivariate analysis.

RESULTS

There were 33 patients with 39 episodes of SBP. Their mean age was 64.5 years and 69.7% were male. The commonest aetiology of cirrhosis was hepatitis B (27.3%). The Median Model for End-stage Liver Disease (MELD) score was 17; 33.3% had acute-on-chronic liver failure and 60.6% had septic shock at presentation. N-SBP occurred in 25.6% of SBP cases. N-SBP was more commonly associated with MDROs, previous antibiotic use in the past three months (p = 0.014) and longer length of stay (p = 0.011). The 30-day and 90-day mortality among SBP patients was 30.8% and 51.3%, respectively. MELD score > 20 was a predictor for 30-day mortality. N-SBP and MELD score > 20 were predictors for 90-day mortality.

CONCLUSION

N-SBP was significantly associated with recent antibiotic use, longer hospitalisation, more resistant organisms and poorer survival among patients with SBP. N-SBP and MELD score predict higher mortality in SBP. Judicious use of antibiotics may reduce N-SBP and improve survival among cirrhotic patients.

Telomere length as a predictor of response to Pioglitazone in patients with unremitted depression: a preliminary study

We studied peripheral leukocyte telomere length (LTL) as a predictor of antidepressant response to PPAR-γ agonist in patients with unremitted depression. In addition we examined correlation between LTL and the insulin resistance (IR) status in these subjects. Forty-two medically stable men and women ages 23-71 with non-remitted depression participated in double-blind placebo-controlled add-on of Pioglitazone to treatment-as-usual. Oral glucose tolerance tests were administered at baseline and at 12 weeks. Diagnostic evaluation of psychiatric disorders was performed at baseline and mood severity was followed weekly throughout the duration of the trial. At baseline, no differences in LTL were detected by depression severity, duration or chronicity. LTL was also not significantly different between insulin-resistant and insulin-sensitive subjects at baseline. Subjects with longer telomeres exhibited greater declines in depression severity in the active arm, but not in a placebo arm, P=0.005, r=-0.63, 95% confidence interval (95% CI)=(-0.84,-0.21). In addition, LTL predicted improvement in insulin sensitivity in the group overall and did not differ between intervention arms, P=0.036, r=-0.44, 95% CI=(-0.74,0.02) for the active arm, and P=0.026, r=-0.50, 95% CI=(-0.78,-0.03) for the placebo arm. LTL may emerge as a viable predictor of antidepressant response. An association between insulin sensitization and LTL regardless of the baseline IR status points to potential role of LTL as a non-specific moderator of metabolic improvement in these patients.

Comparative in vitro cytotoxicity study on uncoated magnetic nanoparticles: effects on cell viability, cell morphology, and cellular uptake

Magnetic iron oxide nanoparticles (MIONPs) must be biocompatible, and a thorough knowledge on their potential cytotoxicity is crucial for their biomedical applications. However, the detailed study about the effects of iron oxide nanoparticles on cell viability, cell morphology, and cellular uptake of different mammalian cells is still insufficient. In this paper, comparative cytotoxicity study of uncoated magnetite nanoparticles at different concentrations was performed on human cervical cancer cell line (HeLa) and immortalized normal human retinal pigment epithelial cell line (RPE). The size, structure, and magnetic behavior of the MIONPs were characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD), and vibrating sample magnetometry (VSM) respectively. After 24-hour incubation with the MIONPs, the cell viability was determined by live/dead assay, the cell morphology at high magnification was observed under scanning electron microscopy (SEM), and the cellular uptake of MIONPs was measured under TEM and verified by energy-dispersive X-ray spectroscopy (EDX) analysis. Our results indicate that the uncoated MIONPs at a high concentration (0.40 mg/ml) were toxic to both HeLa and RPE cells. However, the cytotoxicity of uncoated MIONPs at low concentrations was cell-type specific, and RPE cells were more susceptible to these MIONPs than HeLa cells. The effects of the MIONPs on cell morphology and the nanoparticles uptake also showed different features between these two cell lines. Hence cell type should be taken into consideration in the in vitro cytotoxicity study of uncoated MIONPs. Additionally, it should be noticed that the cell morphological changes and the uptake of nanoparticles can take place even though no toxic effect of these MIONPs at low concentrations was reflected in the traditional cell viability assay.

Cooling field and ion-beam bombardment effects on exchange bias behavior in NiFe/(Ni,Fe)O bilayers

The dependence of the cooling field and the ion-beam bombardment on the exchange bias effects in NiFe/(Ni,Fe)O bilayers were investigated. The positive exchange bias was found in the zero-field-cooled (ZFC) process whereas a negative exchange bias occurred in the FC process. The increased exchange field, H(ex) with increasing (Ni,Fe)O thicknesses indicates the thicker the AF (Ni,Fe)O, the stronger the exchange coupling between the NiFe layer and the (Ni,Fe)O layer. In addition, the dependence of the H(ex) (ZFC vs. FC) on the (Ni,Fe)O thicknesses reflects the competition between the applied magnetic field and the (Ni,Fe)O surface layer exchange coupled to the NiFe layer. Further, an unusual oscillating exchange bias was observed in NiFe/(Ni,Fe)O bilayers that results from the surface of the (Ni,Fe)O layer being bombarded with different Ar-ion energies using End-Hall deposition voltages (V(EH)) from 0 to 150 V. The behavior of the H(ex) and the H(c) with the V(EH) is attributed to the surface spin reorientation that is due to moderate ion-beam bombardment effects on the surface of the (Ni,Fe)O layer. Whether the (Ni,Fe)O antiferromagnetic spins are coupled to the NiFe moments antiferromagnetically or ferromagnetically changes the sign of the exchange bias.

Adenocarcinoma of the duodenum

Adenocarcinoma of the duodenum is an exceedingly rare disorder. Its vague and non-specific symptoms often lead clinicians and patients to suspect other more benign differential diagnoses. Improved endoscopy and radiology have enabled more of these cases to be unearthed. Definitive surgery is the only means of potential cure, with the prognosis being significantly better for node-negative patients. We present a case of a 52-year-old man who underwent a Whipple's operation for this uncommon disease and a literature review of the subject.

Tuning the exchange bias in NiFe/Fe-oxide bilayers by way of different Fe-oxide based mixtures made with an ion-beam deposition technique

We have investigated the structural and magnetic properties of ion-beam deposited polycrystalline NiFe (25 nm)/Fe-oxide (35 nm) bilayers. A film prepared with an assist beam O2 to Ar gas ratio of 0% during deposition had a bottom layer that consisted of pure b.c.c. Fe (a = 2.87 A) whereas films prepared with 19%O2/Ar and 35%O2/Ar had either Fe3O4 (a = 8.47 angstroms) or alpha-Fe2O3 (a = 5.04 angstroms, c = 13.86 angstroms) bottom layers, respectively. Cross-sectional transmission electron microscopy revealed a smooth interface between the top nano-columnar NiFe and bottom nano-columnar Fe-oxide layer for all films. At room temperature, the observed coercivity (Hc approximately 25 Oe) for a film prepared with 19% O2/Ar indicates the existence of a magnetically hard ferrimagnetic Fe3O4 phase that is enhancing the plain NiFe (Hc approximately 2 Oe) by way of exchange coupling. A significant amount of exchange bias is observed below 50 K, and at 10 K the size of exchange bias hysteresis loops shift increases with increasing oxygen in the films. Furthermore, the strongest exchange coupling (H(ex) approximately 135 Oe at 10 K) is with alpha-Fe2O3 (35% O2/Ar) as the bottom film layer. This indicates that the pure antiferromagnetic phases work better than ferrimagnetic phases when in contact with ferromagnetic NiFe. H(ex) (T) is well described by an effective AF domain wall energy that creates an exchange field with a (1 - T/T(crit)) temperature dependence. Hc (T) exhibits three distinct regimes of constant temperature that may indicate the existence of different AF spin populations that couple to the FM layer at different temperatures.

Ethnobotanical study of medicinal plants used by the Jah Hut peoples in Malaysia

CONTEXT

An ethnobotanical study was carried out among the Jah Hut people who live in the central part of peninsular Malaysia.

MATERIALS AND METHODS

The information on the medicinal plants was obtained from interview with a traditional medicinal man. The traditional uses and remedies were documented. The literature searches were carried out for the evaluation on the current status of investigations on these plants.

RESULTS

In this study, we present 16 species of plants, which are commonly used among the Jah Hut people to cure some common diseases.

DISCUSSION

This study is important to preserve the knowledge of medicinal plants used by Jah Hut people. The surveys of phytopharmacological literatures of these plants have great pharmacological and ethnobotanical significance.

Dietary oxidized oil influences the levels of type 2 T-helper cell-related antibody and inflammatory mediators in mice

The aim of this present study was to investigate the effect of amount and degree of oxidation of dietary oil on type 2 T-helper cell (TH)-related immune responses. Four groups of BALB/c mice were fed either 50 g soyabean oil/kg (50-S), 50 g oxidized oil/kg (50-O), 150 g soyabean oil/kg (150-S) or 150 g oxidized oil/kg (150-O). After 14 weeks consuming the experimental diets, the mice were immunized with ovalbumin (OVA) plus Al and antigen-specific immunoglobulin (Ig)E, IgG1 and IgG2a, inflammatory mediators such as prostaglandin (PG) E2 and leukotriene (LT)B4 were determined. Higher hepatic microsomal cytochrome P450 was noted in mice fed 150 g oxidized oil/kg compared with those of other groups. OVA-specific IgG1 and IgE were higher in mice fed 150 g oxidized oil/kg compared with those of the other groups. The data suggested the interleukin (IL)-4: interferon (IFN)-gamma ratio was higher in mice fed 50 g dietary oxidized oil/kg compared with that of the 50-S group. The IL-5:IFN-gamma ratios were higher in the 150-S and 150-O groups than in the 50-S and 50-O groups. PGE2 and LTB4 produced by macrophages stimulated by lipopolysaccharide were highest in mice in the 150 g oxidized oil/kg group. The data suggested that an increased intake of oxidized oil might exert an unfavourable effect on the TH2 response involved in allergic disease.

Identification of core sequences involved in metabolism-dependent nuclear protein binding to the rat insulin-like growth factor I gene

In the liver, most insulin-like growth factor I (IGF-I) transcripts originate in exon 1, where important cis-regulatory regions are located downstream from the major transcription initiation sites. Within these regions, we have attempted to identify sequences which are involved in the decrease in IGF-I gene transcription associated with diabetes mellitus. The function of different genomic templates was assessed by in vitro transcription, which revealed a consistent 50-80% decrease in the activity of nuclear extracts from streptozotocin-diabetic as compared with normal rats. The disparity in transcriptional activity between normal and diabetic nuclear extracts was reduced with templates containing 11-bp mutations within DNase I protected regions III or V (+42 and +129 bp, respectively, from the major transcription initiation site), but a mutation between regions IV and V had little effect. Within region III, gel mobility shift analysis and methylation interference studies indicated that DNA-protein interactions involve a GCGC core sequence. In region V, gel mobility shift studies and uracil interference analysis revealed interactions involving a TTAT core. While gel mobility shift analysis and transient transfection studies indicate that the GCGC core sequence in region III recognizes C/EBP, the AT-rich sequence in region V is likely to recognize a protein with homeodomain characteristics. Identification of the nuclear factor(s) interacting with regions III and V, downstream from exon 1 initiation sites, will be important for understanding the mechanism of reduced IGF-I gene transcription due to diabetes mellitus.

[Inhibition of gastric myoelectric activity and gastric motility by microinjection of substance P into dorsal vagal nucleus in rats]

The present investigation showed that microinjection of substance P (SP) into dorsal vagal nucleus inhibited gastric myoelectric fast wave and gastric motility. The effect could be blocked by SP antiserum or SP antagonist [Arg6, D-Trp7,9, N-Me-Phe8]-SP6-11 or vagotomy. Depletion of sympathetic transmitters by reserpine did not affect induction of the inhibition. The results indicate that both exogenous and endogenous SP of dorsal vagal nucleus decrease the gastric myoelectric fast wave and motility, which is mediated by vagus nerve.

[Inhibitory effect of substance P of caudate nucleus on gastric motility via substantia nigra and dorsal vagal nucleus mediated by vagus nerve]

Effects of lesion of bilateral hypothalamus (LH), substantia nigra and dorsal vagal nucleus as well as their efferent pathway on the inhibition of gastric myoelectric fast wave and gastric motility due to injection of substance P (SP) to caudate nucleus were studied in rats. The experimental results showed that this induced inhibition was independent of the presence of intact LH but abolished by lesioning substantia nigra, dorsal vagal nucleus or vagus nerve. Depletion of sympathetic transmitter by reserpine did not affect the occurrence of the inhibition. Thus, it appears that the gastric inhibitory effect of caudate nucleus SP is mediated via substantia nigra and dorsal vagal nucleus to vagus nerve.

In vitro transcription of the rat insulin-like growth factor-I gene

Although the liver is the major source of circulating insulin-like growth factor-I (IGF-I), relatively little is known about the regulation of IGF-I gene transcription in this tissue. Since transcripts are initiated largely in exon 1, we established an in vitro transcription system to evaluate activation of transcription via the major exon 1 initiation site. Transcription of a G-free cassette reporter was directed by rat IGF-I genomic fragments, and the adenovirus major late promoter was used as an internal control. Tissue specificity was demonstrated by a 60-90% decrease in transcripts with spleen extracts as compared with liver. 54 base pairs (bp) of upstream sequence were sufficient to direct IGF-I gene transcription, and activity increased 5-fold with 300 bp of upstream sequence. DNase I footprinting revealed four protected regions between -300 and -60 bp; binding was confirmed by gel shift analysis, and tissue specificity was demonstrated by reduced shifts with spleen extracts. The necessity of transcription factor binding to such sites was established by competition analysis, which revealed a specific decrease in IGF-I transcription in the presence of a competing fragment. Use of this in vitro transcription system should permit analysis of the function of individual transcription factors involved in regulation of IGF-I gene expression.

Transcriptional regulation of the rat insulin-like growth factor-I gene involves metabolism-dependent binding of nuclear proteins to a downstream region

Insulin-like growth factor-I (IGF-I) gene transcription is mediated largely via exon 1. In an initial search for regulatory regions, rat hepatocytes were transfected with IGF-I constructs. Since omission of downstream sequences led to reduced expression, we then used in vitro transcription to evaluate potential metabolic regulation via downstream regions. With templates including 219 base pairs of downstream sequence, transcriptional activity was reduced 70-90% with hepatic nuclear extracts from diabetic versus normal rats. However, activity was comparable with templates lacking downstream sequences. The downstream region contained six DNase I footprints, and templates with deletion of either region III or V no longer provided reduced transcriptional activity with nuclear extracts from diabetic rats. Nuclear protein binding to regions III and V appeared to be metabolically regulated, as shown by reduced DNase I protection and activity in gel mobility shift assays with nuclear extracts from diabetic rats. Southwestern blotting probes corresponding to regions III and V recognized a approximately 65-kDa nuclear factor present at reduced levels in diabetic rats. These findings indicate that a downstream region in exon 1 may be important for both IGF-I expression and metabolic regulation. Altered concentration or activity of a transcription factor(s) binding to this region may contribute to reduced IGF-I gene transcription associated with diabetes mellitus.

[Participation of dopamine on the muscarinergic inhibitory effect of substance P on gastric myoelectric activity and motility]

Our previous study showed that microinjection of substance P (SP) into caudate nucleus inhibits gastric myoelectric fast wave and gastric motility, an effect mediated by muscarinic receptor. The present investigation showed that this effects of SP could be blocked by coinjected SP antiserum or SP antagonist [Arg6, D-Trip7,9, MePhe8]-SP6-11 or D2 dopamine antagonist haloperidol. In addition, microinjection of dopamine (DA) into caudate nucleus could also inhibit gastric fast wave and motility, an effect again being blockable by coinjected DA antagonist haloperidol or atropine. Thus, it appears that the muscarinergic inhibitory effect of SP on gastric fast wave and motility is mediated by D2 dopamine receptor.

[Inhibition of gastric myoelectric activity and gastric motility induced by microinjection of substance P into caudate nucleus in mouse]

Changes of gastric myoelectric fast wave, slow wave and gastric motility were studied after microinjection of substance P or ACh into caudate nucleus in an attempt to find the interaction between the two substances. Gastric myoelectric activity and motility were recorded by a RM-6200 four channel recorder and then delivered to a IBM-PC computer for analysis. After microinjection of SP or ACh into caudate nucleus, the gastric myoelectric fast wave and gastric motility were significantly suppressed, while the slow wave was not significantly changed.

[Effect and its mechanism of substance P on contractile activity of isolated antral muscle strips of rat]

The present study was aimed at investigating the effect of substance P (SP) on the contractile activity of isolated antral muscle strips of rat and its underlying mechanism. Isolated strips were incubated in an organ bath into which SP was added with or without pretreatment of some antagonists or inhibitors. The results were as follows: (1) SP increased the contractile amplitude of the strips in a dose-dependent manner from 8 x 10(-11) to 8 x 10(-7) mol. At 4 x 10(-8) mol the amplitude was increased by 160.9 +/- 23.0%, while the automaticity of the strips was not affected. (2) This effect of SP could be partially inhibited by hexamethonium (ganglionic blocker), cyproheptadine (blocker of 5-HT2 receptor), diphenhydramine (blocker of H1 receptor), or aminophylline (inhibitor of phosphodiesterase), but not by atropine, propranolol, phentolamine, haloperidol, or naloxone. These results suggested that SP might be a non-cholinergic excitatory transmitter. Its spasmogenic action might be mediated by activating 5-HT neurons, which elicited release of histamine or directly acted on muscle cells.

Effects of Adrenoceptor Agonists and Antagonists on Cardiovascular Functional Parameters in Rats

The effects of intravenous administration of adrenoceptor agonists and antagonists on electrocardiographic or blood pressure (BP) functional parameters were assessed in urethane-anesthetized rats. The responses of cardiovascular functional parameters produced by these drugs included: (1) isoproterenol decreased the duration of a whole BP cycle (Wd), duration of the diastolic wave (Dd), peak amplitude of the systolic wave (SYa), amplitude of the diastolic notch (DNa), amplitude of the diastolic wave (DWa), pulse pressure (dp) and mean arterial pressure (mp) but increased the heart rate (HR) accompanied by prolonged R-R (RR) or P-P interval (PP) (2) propranolol decreased SYa, DNa, dp, mp, HR, the amplitude of the P wave (Pa) and amplitude of the S wave (Sa) but increased the duration of the QRS wave, P-R interval, duration of the R wave (Rd) and duration of the P wave (Pd); (3) adrenaline decreased HR (accompanied by prolonged RR and PP), Rd, Pa and amplitude of the T wave (Ta) but increased Pd, Wd, Dd, DNA, the time interval between aortic valve opening and closure (Dw), dp, mp, amplitude of the Q wave and amplitude of the R wave (Ra); (4) noradrenaline decreased HR (accompanied by prolonged RR and PP) and Pa but increased Wd, Pd, SYa, DNa, Dw, dp, mp, Ra and Ta; (5) phenylephrine decreased HR (accompanied by prolonged RR and PP) and Pa but increased Wd, Dd, DNa, mp and Ra; (6) phentolamine decreased SYa, DNa, DWa, Dw, dp and mp. This study illustrates the utility of the automated electrocardiogram (ECG) and BP analysis system for investigation of adrenoceptor agonists and antagonists. The use of this methodology not only reproduced most of cardiovascular functional parameter effects produced by these drugs using the conventional methodology but also realizes some new information about the drug-induced ECG or BP waveform effects.

Microcomputer-aided system for electrocardiograms and blood pressure analysis during drug-induced transient periods

In the current experiments, we have developed a microcomputer-aided system for amplitude and duration parameter analysis of electrocardiogram (ECG) and blood pressure (BP) waveforms during the drug-induced transient period. Both ECG and BP are monitored, amplified and recorded using standard techniques. For studying the parameter variation trend, the time course of each parameter was produced. Based on these requirements, the present system combined data acquisition, data selection, data analysis, graph plotting and some experimental techniques to meet the need. Generalized human ECG and arterial BP waveforms were used in this system to expand its usable ranges. From the time course graph plotting, the variation trend of each parameter during each drug-induced transient period was obtained thereafter. The main advantages of this system include: (1) transient analysis--the system is suitable for complete and precise parameter analysis of human and animal ECG and BP in the drug-induced transient period; (2) ease of construction--the simplified hardware interface and IBM PC-AT compatible system make this system easy to be constructed; (3) ease of operation--modular data acquisition, processing and analysis procedures make this system easy to be operated; (4) high expansion potential--the modular hardware interface and modular software procedure make this system easy to be expanded; (5) wide utility--the system can be applied to any other research areas which involve the parameter analysis of ECG and BP.

[Effect of bile salt in duodenum on gastric myoelectric activity and motility of mouse with a preliminary study of its neuromechanism]

Changes of gastric myoelectric fast wave, slow wave and gastric motility were studied after intraduodenal infusion of sodium taurocholate (ST) in an attempt to search the concerned neuromechanism. Frequency and total amplitude of the fast wave and slow wave of gastric myoelectric activity and of gastric contractile wave were recorded every five minutes before and after intraduodenal infusion of ST under the background action of various drugs. The frequency and amplitude were expressed in percentage change of the respective premedication value. After intraduodenal infusion of ST (n = 10) the frequency and the amplitude of fast wave and gastric contractile wave were suppressed. Blocking anesthesia of celiac plexus, reserpinization and intravenous infusion of carbachol could eliminate the inhibition induced by ST, which could be partly eliminated by intravenous infusion of propranolol but not affected by phentolamine at all. The results demonstrate that intraduodenal infusion of bile salt suppresses the fast wave of gastric myoelectric activity and gastric motility, most probably controlled by efferent sympathetic adrenergic fibres through beta-receptor.