Ultrasensitive malaria detection system for Anopheles mosquito field surveillance using droplet digital PCR

Malaria remains a significant global public health concern, with a recent increase in the number of zoonotic malaria cases in Southeast Asian countries. However, limited reports on the vector for zoonotic malaria exist owing to difficulties in detecting parasite DNA in Anopheles mosquito vectors. Herein, we demonstrate for the first time that several Anopheles mosquitoes contain simian malaria parasite DNA using droplet digital PCR (ddPCR), a highly sensitive PCR method. An entomological survey was conducted to identify simian malaria vector species at Phra Phothisat Temple (PPT), central Thailand, recognized for a high prevalence of simian malaria in wild cynomolgus macaques. A total of 152 mosquitoes from six anopheline species were collected and first analyzed by a standard 18S rRNA nested-PCR analysis for malaria parasite which yielded negative results in all collected mosquitoes. Later, ddPCR was used and could detect simian malaria parasite DNA, i.e. Plasmodium cynomolgi, in 25 collected mosquitoes. And this is the first report of simian malaria parasite DNA detection in Anopheles sawadwongporni. This finding proves that ddPCR is a powerful tool for detecting simian malarial parasite DNA in Anopheles mosquitoes and can expand our understanding of the zoonotic potential of malaria transmission between monkeys and humans.

Histone H3.3 variant plays a critical role on zygote-to-oocyst development in malaria parasites

The Plasmodium life cycle involves differentiation into multiple morphologically distinct forms, a process regulated by developmental stage-specific gene expression. Histone proteins are involved in epigenetic regulation in eukaryotes, and the histone variant H3.3 plays a key role in the regulation of gene expression and maintenance of genomic integrity during embryonic development in mice. However, the function of H3.3 through multiple developmental stages in Plasmodium remains unknown. To examine the function of H3.3, h3.3-deficient mutants (Δh3.3) were generated in P. berghei. The deletion of h3.3 was not lethal in blood stage parasites, although it had a minor effect of the growth rate in blood stage; however, the in vitro ookinete conversion rate was significantly reduced, and the production of the degenerated form was increased. Regarding the mosquito stage development of Δh3.3, oocysts number was significantly reduced, and no sporozoite production was observed. The h3.3 gene complemented mutant have normal development in mosquito stage producing mature oocysts and salivary glands contained sporozoites, and interestingly, the majority of H3.3 protein was detected in female gametocytes. However, Δh3.3 male and female gametocyte production levels were comparable to the wild-type levels. Transcriptome analysis of Δh3.3 male and female gametocytes revealed the upregulation of several male-specific genes in female gametocytes, suggesting that H3.3 functions as a transcription repressor of male-specific genes to maintain sexual identity in female gametocytes. This study provides new insights into the molecular biology of histone variants H3.3 which plays a critical role on zygote-to-oocyst development in primitive unicellular eukaryotes.

Diameters of the optic sheath and superior ophthalmic vein can expand and contract at positional changes: a magnetic resonance imaging study

PURPOSE

This study aimed to explore the diameters of the optic sheath (OSD) and superior ophthalmic vein (SOVD) in response to positional changes using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Fifty adult outpatients who presented to the hospital underwent thin-slice coronal T2-weighted MRI in the supine position followed by the prone position.

RESULTS

The OS and SOV were well delineated in all the patients. The OSD in the anterior orbit was measured in the supine and prone positions on both sides. In addition, the SOVD in the anterior and posterior orbits was measured in the supine and prone positions on both sides. The OSD demonstrated an increase on both sides in 100% of the cases. The SOVD demonstrated an increase on both sides in 94% of the cases, whereas the remaining 6% demonstrated a decrease. The OSD measured at the anterior orbit and the SOVD at the anterior and posterior orbits significantly increased on both sides with positional changes from the supine to the prone position.

CONCLUSION

OSD and SOVD may expand and contract in response to alterations in the intracranial pressure and venous flow patterns. MRI examination in the supine position combined with positional changes can help to better understand the OS and SOV as dynamic structures.

Dental, skeletal and soft tissue changes after bimaxillary protrusion treatment with temporary anchorage devices using different retraction mechanics

BACKGROUND

Temporary anchorage devices (TADs), which are absolute anchorage, are used for retraction of the anterior teeth in cases of severe bimaxillary protrusion. There have been a number of studies regarding anterior tooth movement using TADs performed by simulation systems and actual treated materials with sliding mechanics. However, there are few studies regarding anterior tooth movement using TADs treated by loop mechanics The purpose of this study was to investigate the effect of TADs in anterior tooth movement using loop mechanics performed in actual cases of bimaxillary protrusion.

METHODS

This study was performed in 20 adult patients with severe bimaxillary protrusion treated with four bicuspid extraction with sliding or loop mechanics (n = 10 in each mechanics) using TADs. The skeletal and denture patterns, as well as the soft tissue profile from pre-treatment (T0) and post-treatment (T1) lateral cephalograms, were compared between sliding and closing loop mechanics.

RESULTS

The use of TADs is useful for retraction of anterior teeth without molar anchorage loss. in sliding and loop mechanics. The upper anterior teeth were less lingual tipped and lower anterior teeth were more upright resulting in less clockwise rotation of the occlusal plane in loop mechanics compared to sliding mechanics.

CONCLUSION

An oblique retraction force vector with a lower point of application causes less intrusion and more lingual tipping of upper anterior teeth as well as more clockwise rotation of the occlusal plane compared to a parallel retraction force vector.

Association of steroid administration with larger coronary artery abnormalities in patients with Kawasaki disease

We sought to elucidate the risk profiles of patients with Kawasaki disease who developed coronary artery abnormalities through a retrospective analysis with special reference to steroid treatment. Demographics of the patients were obtained from medical records, and characteristics of the coronary artery abnormalities were evaluated by echocardiography and coronary angiography, which included number, location, size, and length of coronary artery abnormalities (we evaluated by cardiac catheterisation with the American Heart Association classification with segments). We divided the patients into two groups based on steroid use and compared their characteristics and the complications of coronary artery abnormalities and cardiac events. A total of 29 patients were diagnosed with coronary artery abnormalities by echocardiography and coronary angiography during the study period (24 male; median age, 24 months [range: 2-84 months]). Eighteen patients were treated with aspirin and intravenous immunoglobulin (63%, non-steroid group), whereas 11 received aspirin and intravenous immunoglobulin plus steroids (37%, steroid group). No significant differences were found in the number and location of coronary artery abnormalities between the steroid and non-steroid groups. However, the size and number of segments for coronary artery abnormalities were significantly larger and shorter, respectively, in the steroid group (z-score: non-steroid group 6.3 versus steroid group 8.7; p < 0.01). The coronary artery abnormality segments under steroid use were also shorter (non-steroid group versus steroid group, two segments versus one segment; p = 0.02). Coronary artery abnormality size was larger in patients who used steroids than that of non-steroids. This study showed that steroid use significantly affected coronary artery abnormality size in patients with Kawasaki disease. However, cardiac complications from coronary artery abnormalities and cardiac events were comparable between the steroid and non-steroid groups. Further prospective, multicentre studies are needed to confirm these findings.

Objective Evaluation With Noncontrast Computed Tomography Can Reveal Calcified Plaque Solidity in Peripheral Artery Diseases

PURPOSE

The presence of severely calcified plaque remains problematic in endovascular therapy, and no specific endovascular treatment strategy has been established. Estimating plaque solidity before the procedure may help operators penetrate calcified plaque with a guide wire. The aim of this study was to establish a method of measuring plaque solidity with noncontrast computed tomography (CT).

METHODS

This retrospective, single-center study included consecutive patients who, between October 2020 and July 2022, underwent noncontrast 5 mm and 1 mm CTs before endovascular therapy to penetrate calcified plaque with a wire in the common femoral, superficial femoral, and popliteal arteries. Three cross-sectional CT slices were selected. To target a calcified plaque lesion, the operator identified a region of interest, which corresponded to 24×24 pixels, and Hounsfield unit (HU) values of each pixel were displayed on the CT image. The average HU values and the ratio of number of pixels of lower values (130-599 HU) represented plaque solidity. We used the Mann-Whitney-Wilcoxon rank-sum test and the chi-square test to compare the solidity of plaques penetrated and not penetrated by the wire.

RESULTS

We evaluated 108 images of 36 calcified plaque lesions (in 19 patients). The wire penetrated 28 lesions (77.8%) successfully. The average HU value was significantly lower in the lesions that the wire penetrated than in the others, in both the 5 mm CT slices (434.7±86.8 HU vs 554.3±112.7 HU, p=0.0174) and 1 mm slices (497.8±103.1 HU vs 593.5±114.5 HU, p=0.0381). The receiver operating curve revealed that 529.9 and 533.9 HU in the 5 and 1 mm slices, respectively, were the highest values at which wires could penetrate. Moreover, at the lesions that were penetrates successfully, the ratio of number of lower HU value pixels was significantly higher both in 5 mm slice CTs (74.7±13.4 vs 61.7±13.1%, p=0.0347) and 1 mm (68.7±11.8 vs 57.1±11.4%, p=0.0174).

CONCLUSION

The use of noncontrast CT to evaluate plaque solidity was associated with successful wire penetration of calcified lesions in peripheral arteries.

CLINICAL IMPACT

This study revealed an association between the wire penetration inside calcified plaque and plaque solidity estimated using non-contrasted computed tomography. The mean Hounsfield unit values of three cross-sections in calcified plaques were associated with the successful wire penetration. This wire penetration difficulty is associated with extended procedure time, excessive radiation exposure, usage of extra contrast agents, and increased medical costs. Therefore, estimating calcified plaque solidity before procedure enables us to choose effective and lean procedures. In addition, to predict the success of dilating calcified plaque from the inside is also beneficial when the operator wants to avoid extra scaffold implantation for target lesions.

Time to Pain Relapse After Palliative Radiotherapy for Bone Metastasis: A Prospective Multi-institutional Study

BACKGROUND/AIM

Low risk asymptomatic bone metastasis (LRABM) without gross osteolytic changes tends to be out of indication for radiotherapy. The aim of this study was to evaluate the time between the end of palliative radiotherapy of bone metastasis (BM) until the start of new pain, in patients with painful BM.

PATIENTS AND METHODS

Patients with BM were prospectively assessed for location and strength of pain every month for one year after radiotherapy. The correlation of pain relapse at irradiated site, and pain onset outside the irradiated site was evaluated with sex, age, primary tumor, pathology of tumor, visceral metastases, baseline scores for Eastern Cooperative Oncology Group performance status (PS), and baseline verbal rating scale (VRS).

RESULTS

A hundred and thirty-two patients were included (79 males and 53 females). Median age was 66 years. Primary sites were lung (n=60), breast (n=17), colon (n=12), prostate (n=11), and others (n=33) (one patient had two primary sites). Median follow-up was 185 days. Pain relief was observed in 92 patients (86.0%). Out of them, pain progression was observed in 69.6%. Median time to pain progression was 75.5 days. Pain onset outside the irradiated site was observed in 57 patients (43.2%). Median time to pain onset was 109 days. Out of the 57 patients, 13 (22.8%) had LRABM which existed before the start of radiotherapy. There were 54 patients with LRABM in this study and because many patients had more than one LRABM, the total LRABM sites were 123. Out of them, pain onset was observed within one year after irradiation in 44 (36%) lesions. Median time to pain onset was 67 days, which was the shortest of the three: irradiated site, out of the irradiated site, and LRABM site. Risk factors for high probability of pain onset within one year in LRABM lesions were female sex (showing a trend in univariate analysis), and pelvic, skull and spine metastasis (significant in multivariate analysis).

CONCLUSION

Time to pain onsets in LRABM are relatively short, especially in female patients with pelvic, skull and spine metastasis. In these patients, prophylactic radiotherapy could be an option to consider.

Prevalence and distribution of non-pulmonary vein atrial fibrillation triggers in real-world clinical settings

Background

Epidemiology of non-pulmonary vein (PV) triggers of atrial fibrillation (AF) is not fully known.

Purpose

This study aimed to clarify the prevalence and distribution of non-PV triggers in real-world clinical settings of AF catheter ablation.

Methods

One-thousand and twenty patients undergoing AF ablations were retrospectively analyzed (mean age 65 years old, 702 males (69%), 506 paroxysmal and 514 non-paroxysmal). Induction and observation of AF triggers were attempted using intravenous isoproterenol/adenosine triphosphate and repeated direct current cardioversion during AF in each session. Documentable non-PV AF triggers were characterized in the studied population. Premature atrial contractions that did not initiate AF were excluded.

Results

A hundred and twenty-six non-PV triggers were documented in 108 patients (10.6%). Non-PV trigger was documented in 6.3% of 1st session cases, whereas 30.9% of recurrent cases undergoing multiple sessions (p&lt;0.0001). Left atrial (LA) posterior wall was the most prevalent site (N=34), followed by 30 intra-atrial septum (IAS), 29 superior vena cava (SVC), 13 crista terminalis, 7 right atrial (RA) free wall, 6 LA anterior wall, 3 coronary sinus (CS), 3 left atrial appendage, and 1 persistent left superior vena cava (LSVC). We classified those non-PV triggers into 4 groups; 43 LA, 33 thoracic veins (SVC, CS and LSVC), 30 IAS and 20 RA. Thoracic vein/RA origins were more prevalently detected in paroxysmal AF cases (57%) compared to non-paroxysmal AF (28%) (p&lt;0.01). Conversely, LA origin was more prevalently detected in non-paroxysmal AF cases (48%) compared to paroxysmal AF (20%) (p&lt;0.01).

Conclusions

Prevalence of non-PV trigger in cases undergoing multiple sessions is extremely high, suggesting a particular importance of non-PV trigger targeting in patients with recurrent AF undergoing 2nd or 3rd ablation sessions. Progressive nature of AF with newly generated AF triggers should be under consideration. Distributions of non-PV triggers are largely different between paroxysmal and non-paroxysmal AF. These findings may help ablation strategy regarding non-PV trigger targeting in practice.

Funding Acknowledgement

Type of funding sources: None.

Catheter ablation of persistent atrial fibrillation with heart failure improves hemodynamic status without deteriorating renal function in the elderly

Background/Introduction

Atrial fibrillation (AF) and heart failure (HF) frequently coexist in the elderly people, leading to worse clinical outcomes. HF with preserved ejection fraction (HFpEF) is the most common form of HF in the elderly, particularly in women, associated with AF. Ablation of AF in younger patients with HF with reduced EF (HFrEF) has become an established treatment option. However, clinical impact of ablation for persistent AF accompanying with HF in the elderly remains unclear.

Purpose

This study aimed to evaluate the effect of catheter ablation of persistent AF with heart failure in the elderly.

Methods

Consecutive 70 patients who underwent catheter ablation of persistent AF accompanying with HF (NYHA class&gt; II, mean LVEF 51.7%) in our institution were retrospectively analyzed with regards to their 1-year clinical outcomes, HF markers such as BNP, renal function and transthoracic echocardiographic findings. Patients were dichotomized by age of 75-year-old (31 elderly vs 39 younger subjects) and separately analyzed.

Results

Mean age of the studied population was 70.5 year-old; 79.6±3.8 in the elderly group and 63.2±8.5 in the younger group. The elderly patients were more frequently females (45% vs 21%). Longstanding persistent AF was observed in 32% in the elderly and 28% in the younger group. Circumferential pulmonary vein isolation (PVI) was performed in all patients, with additional ablations of liner lesions and/or non-PV foci as needed. PVI alone was observed in 54.8% in the elderly and 41% in the younger group. There were no serious complications associated with the procedure. During 1 year after ablation, recurrence of AF was observed in 15 patients [6/31 (19%) in the elderly, 9/39 (23%) in the younger]. Readmission due to HF was observed in only 1 patient in the elderly and 2 patients in the younger group (3% vs. 5%, respectively). Cardiovascular events were observed in 3 patients [2/31 (6%) in the elderly, 1/39 (3%) in the younger], but there was no death. The BNP level as well as the NYHA class significantly decreased at 1-year follow-up compared to baseline in the both groups (Figure A and B). There was no change in serum creatinine level in the both groups (Figure C). The left atrial dimension and the LA volume index decreased at 1-year follow-up in the both groups (Figure D and E). The LVEF improved only in the younger group (Figure F).

Conclusions

Ablation of persistent AF in the elderly with HF (mostly with preserved EF) was associated with hemodynamic and functional improvements without deteriorating renal function in a mid-term, which was mostly comparable to the results in the younger.

Funding Acknowledgement

Type of funding sources: None.

Aggressive combined pharmacotherapy for heart failure reduces new onset atrial fibrillation

Backgrounds

Heart failure (HF) is a risk factor for new onset atrial fibrillation (AF), and the new onset AF is associated with a worse prognosis in HF patients. It has been reported that renin-angiotensin system inhibitor (RASi), β-blocker and mineral-corticoid receptor antagonist (MRA) prevent the new onset AF in HF patients. However, the effect of combined pharmacotherapy including angiotensin receptor neprilysin inhibitor (ARNI) and sodium glucose co-transporter 2 inhibitor (SGLT2i) on AF is unknown. We investigated the impact of contemporary regimen of combined pharmacotherapy for HF (RASi/ARNI+β-blocker+MRA+SGLT2i) on new onset AF.

Methods and results

We retrospectively studied rEF and mrEF patients without AF admitted to our hospital due to decompensated HF between 2015 and 2021 (n=366). Long-term (The mean follow-up was 635±421 days) incidence of new onset AF was investigated with regard to medical therapies. Patients were divided into 2 groups; patients with ≤2 HF drugs (n=181) and patients with ≥3 HF drugs (n=185). Patients with ≤2 HF drugs group were older (77.3 vs 67.0 years old, P&lt;0.001), had a poorer renal function (Cre: 1.66 vs 1.09 mg/dl, P&lt;0.001), and had a higher rate of ischemic heart disease (52 vs 38%, P=0.009), whereas left ventricular systolic function was better (EF: 31.9 vs 27.3%, P&lt;0.001). There were 19 (10.5%) new onsets AF in the ≤2 HF drugs group, whereas only 7 (3.8%) had new onsets AF in the ≥3 HF drugs group (HR 0.36, 95% CI 0.15–0.85, P=0.01). All-cause death and hospitalization for HF were fewer in the ≥3 HF drugs group. A multivariate analysis revealed that ≥3 HF drugs use was an independent negative predictor of new onset AF (HR 0.37, 95% CI 0.15–0.93, P=0.03). Even after a propensity score matching of the clinical variables, the incidence of new onset AF was consistently fewer in the ≥3 HF drugs group (HR 0.36, 95% CI 0.13–0.99, P=0.04). Finally, patients with new onset AF had a higher rate of hospitalization for HF in the studied population (HR 9.68, 95% CI 5.67–16.5, P&lt;0.01).

Conclusion

Aggressive combined pharmacotherapy for HF may be associated with fewer new onset AF in patients with HF.

Funding Acknowledgement

Type of funding sources: None.

SICA-mediated cytoadhesion of Plasmodium knowlesi-infected red blood cells to human umbilical vein endothelial cells

Zoonotic malaria due to Plasmodium knowlesi infection in Southeast Asia is sometimes life-threatening. Post-mortem examination of human knowlesi malaria cases showed sequestration of P. knowlesi-infected red blood cells (iRBCs) in blood vessels, which has been proposed to be linked to disease severity. This sequestration is likely mediated by the cytoadhesion of parasite-iRBCs to vascular endothelial cells; however, the responsible parasite ligands remain undetermined. This study selected P. knowlesi lines with increased iRBC cytoadhesion activity by repeated panning against human umbilical vein endothelial cells (HUVECs). Transcriptome analysis revealed that the transcript level of one gene, encoding a Schizont Infected Cell Agglutination (SICA) protein, herein termed SICA-HUVEC, was more than 100-fold increased after the panning. Transcripts of other P. knowlesi proteins were also significantly increased, such as PIR proteins exported to the iRBC cytosol, suggesting their potential role in increasing cytoadhesion activity. Transgenic P. knowlesi parasites expressing Myc-fused SICA-HUVEC increased cytoadhesion activity following infection of monkey as well as human RBCs, confirming that SICA-HUVEC conveys activity to bind to HUVECs.

Jejunogastric intussusception after pancreaticoduodenectomy: a case report

Background

Jejunogastric intussusception (JGI) is a rare, but potentially fatal complication that can occur following gastric surgery, and the reported incidence of JGI is as low as 0.1%. Early diagnosis and treatment are critical for JGI to prevent major complications such as bowel necrosis and death. Although emergency surgery is the standard treatment, endoscopic reduction has also been reported to be effective in JGI patients without bowel necrosis. Several early recurrent cases treated with surgical or endoscopic reduction have been reported. We report an extremely rare case of JGI after pancreaticoduodenectomy (PD) using Child’s procedure that was successfully treated with surgical reduction and fixation.

Case presentation

An 81-year-old man who had undergone PD using Child’s procedure 3 years ago presented to our hospital with epigastric pain and nausea. His vital signs were stable, and abdominal examination revealed mild tenderness with a palpable mass in the mid-epigastrium. Abdominal computed tomography (CT) and gastroscopy revealed a JGI of the efferent loop, and exploratory laparotomy was immediately performed. During the operation, the efferent loop showed no adhesions and was intussuscepted through the gastrojejunostomy into the gastric lumen. An incision in the anterior wall of the stomach revealed no evidence of ischemia of the intussusceptum. The efferent loop was reduced using Hutchinson’s maneuver and fixed to the afferent loop to prevent a recurrence. The postoperative course was uneventful, and there was no sign of recurrence 12 months postoperatively.

Conclusions

JGI after PD is an extremely rare, but has severe complications. Surgery might be the optimal treatment for JGI in terms of preventing recurrence, even in cases without bowel necrosis.

Unbalanced relationships: insights into the interaction between gut microbiota, geohelminths, and schistosomiasis

Hosts and their microbiota and parasites have co-evolved in an adaptative relationship since ancient times. The interaction between parasites and intestinal bacteria in terms of the hosts' health is currently a subject of great research interest. Therapeutic interventions can include manipulations of the structure of the intestinal microbiota, which have immunological interactions important for modulating the host's immune system and for reducing inflammation. Most helminths are intestinal parasites; the intestinal environment provides complex interactions with other microorganisms in which internal and external factors can influence the composition of the intestinal microbiota. Moreover, helminths and intestinal microorganisms can modulate the host's immune system either beneficially or harmfully. The immune response can be reduced due to co-infection, and bacteria from the intestinal microbiota can translocate to other organs. In this way, the treatment can be compromised, which, together with drug resistance by the parasites makes healing even more difficult. Thus, this work aimed to understand interactions between the microbiota and parasitic diseases caused by the most important geohelminths and schistosomiasis and the consequences of these associations.

Reduction in Plasmodium falciparum Pfk13 and pfg377 allele diversity through time in southern Vietnam

Background

Plasmodium falciparum has acquired resistance to artemisinin in Southeast Asia, with mutations in the P. falciparum Kelch-13 (Pfk13) gene associated with the resistance phenotype. The widespread use of Artemisinin-based combination therapy (ACT)s in Southeast Asia has led to the selection and spread of parasites carrying mutations in Pfk13. We characterised the allele diversity of Pfk13 and pfg377, an artemisinin-resistance neutral polymorphic gene, in parasite DNA extracted human blood from in southern Vietnam in 2003, 2012, 2015 and 2018.

Method

This study was conducted in Bu Gia Map commune, Binh Phuoc province, Vietnam, from May 2018 to January 2019. Twenty-four samples from 2018 to 2019, 30 from 2003, 24 from 2012 and 32 from 2015 were analysed. Malaria-infected human blood was collected by finger-prick and used for molecular analysis. A nested-PCR targeting the small subunit ribosomal RNA gene was used for Plasmodium species identification, followed by amplification and nucleotide sequencing of Pfk13 and region 3 of pfg377. Archived blood samples collected in the same region in 2012 and 2015 were also analysed as above for comparison.

Results

The genetic diversity of Pfk13 and pfg377 was lower in 2018–2019 compared to 2012 and 2015. The number of distinct Pfk13 mutants decreased from three in 2012 and 2015, P553L, V568G and C580Y, to one, C580Y in 2018–2019. In 2018–2019, the frequency of C580Y mutant strains was 71% (17/24 isolates). All samples were wild type in 2003. In 2012 and 2015, there were single-strain infections as well as co-infections with two mutant strains or with mutant and wild strains, whereas there were no co-infections in 2018. pfg377 allele diversity decreased from five alleles in 2012 to two alleles in 2018–2019.

Conclusion

The genetic diversity of P. falciparum was reduced at the two genetic loci surveyed in this study, Pfk13 and pfg377. In the case of the former gene, we observed an increase in the prevalence of parasites carrying the C580Y gene, known to confer reduced susceptibility to ACTs. The reduction in the diversity of pfg377 may be linked to the clonal expansion of parasite strains carrying the C580Y mutation, leading to an overall reduction in parasite genetic diversity across the population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-022-00409-4.

Electrocardiographic Diagnosis of Hypertrophic Cardiomyopathy in the Pre- and Post-Diagnostic Phases in Children and Adolescents

BACKGROUND

The usefulness of electrocardiographic (ECG) voltage criteria for diagnosing hypertrophic cardiomyopathy (HCM) in pediatric patients is poorly defined.Methods and Results:ECGs at the 1st grade (mean [±SD] age 6.6±0.3 years) were available for 11 patients diagnosed with HCM at around the 7th grade (13.2±0.3 years). ECGs were available for another 64 patients diagnosed with HCM in the 1st (n=15), 7th (n=32), and 10th (n=17) grades. Fifty-one voltage criteria were developed by grade and sex using 62,841 ECGs from the general population. Voltage criteria were set at the 99.95th percentile (1/2,000) point based on the estimated prevalence of childhood HCM (2.9 per 100,000 [1/34,483]) to decrease false negatives. Conventional criteria were from guidelines for school-aged children in Japan. Of 11 patients before diagnosis, 2 satisfied conventional criteria in 1st grade; 5 (56%) of the remaining 9 patients fulfilled 2 voltage criteria (R wave in limb-lead I [RI]+S wave in lead V3 [SV3] and R wave in lead V3 [RV3]+SV3). Robustness analysis for sensitivity showed RV3+SV3 was superior to RI+SV3. For all patients after diagnosis, RI+SV4 was the main candidate. However, conventional criteria were more useful than voltage criteria.

CONCLUSIONS

Early HCM prediction was possible using RV3+SV3 in >50% of patients in 1st grade. Voltage criteria may help diagnose prediagnostic or early HCM, and prevent tragic accidents, although further prospective studies are required.

Laparoscopic surgery for sigmoid colon cancer with complicated communication between the superior and inferior mesenteric arteries

To perform complete mesocolic excision with central vessel ligation, it is important to recognize the vessel anomaly and the location of the tumor. For left-sided colon cancer, the variations in the course of the left colic artery and accessary middle colic artery must be recognized preoperatively. Here, we describe our experience with a 57-year-old man who was diagnosed with sigmoid colon cancer with complicated inter-mesenteric connections between the inferior mesenteric artery (IMA) and superior mesenteric artery (SMA), possibly due to median arcuate ligament syndrome. We performed laparoscopic sigmoidectomy with low ligation of the IMA to preserve the extremely enlarged left colic artery. The total operative time was 155 minutes, and the estimated total blood loss was 10 mL. The patient was discharged on postoperative day 9 without any postoperative complications. For patients with vascular anomalies in the left-sided mesocolon, preoperatively ruling out SMA stenosis by using angiography and 3-D CT might be important.

Reduction of Pneumocystis jirovecii pneumonia and bloodstream infections by trimethoprim-sulfamethoxazole prophylaxis in patients with rheumatic diseases

Objective: Trimethoprim-sulfamethoxazole (TMP/SMX) prophylaxis against Pneumocystis jirovecii pneumonia (PJP) is routinely administered to patients with rheumatic diseases in Japan. The present study aimed to evaluate the effect of TMP/SMX prophylaxis on PJP and non-central line-associated bloodstream infections (BSIs) in patients receiving high-dose glucocorticoids for the treatment of rheumatic diseases.Method: This study enrolled patients who were admitted between 1 October 2003 and 31 March 2018 and began high-dose glucocorticoid therapy for rheumatic diseases during hospitalization. The observation period was 4 months from the commencement of high-dose glucocorticoid therapy. The effect of TMP/SMX prophylaxis on PJP and non-central line-associated BSI was analysed.Results: Of the 437 patients included in the study, 376 received TMP/SMX prophylaxis and 61 patients did not. During the observation period, TMP/SMX prophylaxis was discontinued in 76 patients (20.2%). Three PJP cases (0.7%) occurred. Among the 399 patients included in our analysis of non-central line-associated BSI, eight experienced non-central line-associated BSI (2.0%). Among the covariates, TMP/SMX prophylaxis was associated with reduced PJP and non-central line-associated BSI incidence [odds ratio (OR) 0, 95% confidence interval (CI) 0.00-0.38, and OR 0.08, 95% CI 0.01-0.42, respectively].Conclusion: Routine TMP/SMX prophylaxis reduced the incidence of both PJP and BSI in patients with rheumatic diseases undergoing high-dose glucocorticoid therapy.

Presence of low voltage area predicts atrial tachyarrhythmia inducibility with atrial burst pacing after pulmonary vein isolation

Background

Induction of atrial fibrillation (AF)/atrial tachycardia (AT) by atrial burst pacing following ablation procedure may reflect the presence of residual substrates in the atria that maintain AF. However, the relation between the inducibility and left atrial low voltage area (LVA) has not been established.

Methods

Fifty-nine patients (65 years old, 43 males) with persistent AF who underwent pulmonary vein isolation (PVI)-based ablation were studied. All patients underwent left atrial voltage mapping during sinus rhythm and atrial burst pacing after PVI. Atrial burst pacing was performed with 30-beat at an amplitude of 10V from the ostium of the coronary sinus; increasing from 240 to 320 ppm in steps of 20 ppm or failure to 1:1 atrial capture. Inducibility was defined as AF/AT lasting more than 5 minutes following burst pacing. Left atrial LVA and other co-variates were analyzed with regard to burst pacing positivity.

Results

AF/AT was induced by burst pacing in 23 patients (39%). Univariate analysis revealed that past history of stroke, CHADS2 score and presence of left atrial LVA were significantly associated with the inducibility of AF/AT. Multivariate analysis revealed that only the presence of LVA was associated with the inducibility (OR 1.5: per 10% increase; p=0.04). We focused on the relationship between the extent of LVA and burst positivity. AF/AT inducibility increased as low voltage area increased, and it was as high as 72.7% when low voltage area was more than 20% (P&lt;0.05). Interestingly, induced arrhythmia type was AT rather than AF when low voltage area was more than 20%.

Conclusions

Presence of left atrial LVA is an independent predictor of atrial tachyarrhythmia inducibility after PVI in patients with persistent AF. A large amount of low voltage area is related to AT inducibility rather than AF.

Extent of LVA and burst positivity

Funding Acknowledgement

Type of funding source: None

Early follow-up visit at outpatient care after discharge improves 2-year heart failure readmission rate and long-term prognosis in patients with decompensated heart failure

Background/Introduction

It has been reported that heart failure (HF) readmission has not declined even with current cardiology practice in the last 10 years. It has been also reported that HF readmission tends to occur shortly after discharge. This may be due to overwork and excessive salt intake after discharge. In other words, it is conceivable that patient factors are largely attributable, which should be intervene for better clinical outcomes.

Purpose

We hypothesized and investigated whether an early follow-up visit at outpatient care within 2 weeks after discharge affects the re-admission rate and prognosis in patients with decompensated HF.

Methods

We retrospectively investigated consecutive 407 hospitalized patients due to decompensated HF. After exclusion of 99 patients with in-hospital death, transfer to another hospital and readmission within 2 weeks after discharge, consecutive 308 out of 407 patients were investigated. Two-year clinical outcomes after discharge were collected and analyzed. An early follow-up was defined as an outpatient care visit within 2 weeks after discharge with the adjustment of drugs and/or the lifestyle guidance, if necessary. A setting of early follow-up in each patient was according to a physician's discretion.

Results

One hundred-twenty eight patients underwent early follow-up visits and other 180 patients were without it. An univariate analysis showed that the early follow-up was significantly associated with a lower HF readmission rate during 2 years (17.1% in the early follow-up group, 34.4% in the control group, p≤0.001, OR=0.397, 95% CI=0.230–0.685, Figure) and a 2-year composite adverse outcome (all cause death and HF readmission; 18.7% vs. 40.5%, p&lt;0.001, OR=0.332, 95% CI=0.196–0.563, Figure). To exclude possible relationships of other co-variable factors, we performed a multivariate analysis about the association with HF readmission rate and the 2-year composite adverse outcome (co-variate factors as follows are included; factors of which p-value was less than 0.1 and general confounding factors). The multivariate analysis showed that the early follow-up was independently associated with HF readmission during 2 years (p=0.002, OR=0.376, 95% CI=0.197–0.716) and the 2-year composite outcome (p&lt;0.001, OR=0.343, 95% CI=0.182–0.648). Finally, we characterized the practical interventions at outpatient care after discharge. Lifestyle guidance was done in all patients. However, medication adjustments were done in only 36.7% patients. Interestingly, whether or not a medication adjustment was done at the early follow-up visit was not associated with the HF readmissions (p=0.781).

Conclusions

The present study suggests that an early follow-up approach after discharge in decompensated HF patients may improve the long-term prognosis. These results were not dependent on whether a medication adjustment was performed or not. An early follow-up may help improve patient factors of HF worsening.

Main results

Funding Acknowledgement

Type of funding source: None

Human toxocariasis, a silent helminthic disease revealed in Savannakhet, Lao PDR

Toxocariasis is a zoonotic helminthiasis caused by the migrating larvae of Toxocara canis and T. cati, common roundworms of dogs and cats. Our previous study in Savannakhet Province of Lao PDR showed an infection rate of 44.1% of Toxocara spp. in dogs. Thus, we investigate if this previous high prevalence in the definitive hosts influenced the occurrence of human toxocariasis. For that we used a 38 kDa recombinant protein derived from T. canis larvae excretion secretion products in ELISA. Human serum samples were collected in the Lahanam area of Savannakhet province. The population attending the study in Lahanam village were aged from 7 to 59 years old (y/o) 65.9% (54/82) were male and 34.1% (28/82) were female. The total percentage of seropositivity to Toxocara sp. was 30.4% (25/82). Males were more likely to test positive for toxocariasis with a risk ratio of 2.70 (CI95 0.87–4.93). No significant differences between ages were seen. However, it was possible to observe an increase of optical density (OD) values in ELISA according to age. The awareness of the health system on the high prevalence of seropositivity to Toxocara sp. in Savannakhet can prevent irreversible consequences as permanent vision loss and seizures caused by this silent chronic disease revealed in the Lahanam area.

•

The first survey for human toxocariasis was carried out in Savannakhet, Lao-PDR.

•

Seropositivity was higher in males than females.

•

Despite no reported clinical cases of toxocariasis 30.4% of seropositivity was found.

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People are at risk of exposure to Toxocara sp. larvae in Savannakhet, Lao-PDR.

Oncologic Reappraisal of Bile Duct Resection for Middle-Third Cholangiocarcinoma

BACKGROUND

Although bile duct resection (BDR) in addition to pancreaticoduodenectomy (PD) is considered a surgical approach in patients with middle-third cholangiocarcinoma (MCC), available prognostic information after BDR remains very limited. The aim of this study was to reappraise BDR from the viewpoint of surgical oncology.

METHODS

Patients who underwent BDR or PD for MCC between 2001 and 2010 at 32 Japanese hospitals were included. Clinicopathological factors were retrospectively compared according to surgical procedure to identify a subset cohort who benefited most from BDR.

RESULTS

During the study, 92 patients underwent BDR (n = 38) or PD (n = 54). BDR was characterized by a shorter operation time, less blood loss, less frequent complications, and lower mortality, than PD. The incidence of positive surgical margins was 26.3% versus 5.6% (P = 0.007). The survival rate after BDR was significantly worse than that after PD: 38.8% versus 54.8% at 5 years (P = 0.035), and BDR was independently associated with deteriorated survival [hazard ratio (HR), 1.76; P = 0.023] by multivariable analysis. In the BDR group, tumor length < 15 mm (HR, 3.38; P = 0.017) and ductal margin length ≥ 10 mm (HR, 2.54; P = 0.018) were independent positive prognostic factors. Stratified by these two favorable factors, the 5-year survival rate was 63.0% in patients with 1/2 factors and 6.7% in those with 0 factors (P < 0.001).

CONCLUSION

In patients with MCC, BDR provided a better short-term and a worse long-term outcome than PD. However, patient selection using tumor length and ductal margin length may allow a favorable survival probability even after BDR.

Case Report: Acute Amebic Colitis Triggered by Colonoscopy: Exacerbation of Asymptomatic Chronic Infection with Entamoeba histolytica Accompanied by Dysbiosis

Recent data show that the gut microbiome plays a role in determining the clinical outcome of Entamoeba histolytica infection. We report the case of a patient who developed recurrent acute amebic colitis (second episode of acute colitis) after colonoscopy. Genotyping of E. histolytica revealed that she developed a second episode of acute amebic colitis with the same genotype as that of the first episode, indicating chronic infection had persisted asymptomatically for > 10 months between the first and second episodes. Analysis of the gut microbiome, in addition to the clinical findings, suggested that dysbiosis at colonoscopy induced the change in the clinical form of E. histolytica infection from asymptomatic chronic infection to symptomatic colitis.

Development of an effective alternative model for in vivo hypnozoite-induced relapse infection: A Japanese macaque (Macaca fuscata) model experimentally infected with Plasmodium cynomolgi

In the present study, we demonstrate that the Japanese macaque (Macaca fuscata) can be used as an effective alternative in vivo model for investigating hypnozoite-induced relapsing infection caused by Plasmodium cynomolgi B strain, and that this model is comparable to the rhesus macaque model. Two female Japanese macaques (JM-1 and JM-2; aged 5 years; weighing about 4.0 kg) were used for the experiment. To produce sporozoites in mosquitoes, blood infected with P. cynomolgi B strain was collected from the donor monkey JM-1 and fed to approximately 200 mosquitoes using the standard artificial membrane feeding method. The isolated sporozoites (2 × 10⁵) were intravenously inoculated into the JM-2 monkey, and the blood stage of the parasite was detected on day 8 after the infection. Chloroquine sulfate (CQ) was intramuscularly administered at a dosage of 6.0 mg/kg into the JM-2 monkey for 6 consecutive days from day 12 onward, after which the parasites disappeared from the peripheral blood. The first relapse occurred on day 26, which was treated again with CQ. Then, the second relapse occurred on day 44, which was cured by CQ treatment followed by the administration of primaquine phosphate (PQ) at a dosage of 1.0 mg/kg/day for 15 days. The JM-2 monkey was observed until 69 days after PQ administration, and there was no relapse during the entire follow-up period. We propose that the Japanese macaque model could contribute not only to drug screening for anti-hypnozoite activity, but could also be used as a powerful tool for investigating hypnozoite biology.

Three-dimensional electron microscopy analysis reveals endopolygeny-like nuclear architecture segregation in Plasmodium oocyst development

The genus Plasmodium is a unicellular eukaryotic parasite that is the causative agent of malaria, which is transmitted by Anopheline mosquito. There are a total of three developmental stages in the production of haploid parasites in the Plasmodium life cycle: the oocyst stage in mosquitoes and the liver and blood stages in mammalian hosts. The Plasmodium oocyst stage plays an important role in the production of the first generation of haploid parasites. Nuclear division is the most important event that occurs during the proliferation of all eukaryotes. However, obtaining the details of nuclear division at the oocyst stage is challenging owing to difficulties in preparation. In this study, we used focused-ion-beam-milling combined with scanning-electron-microscopy to report the 3D architecture during nuclear segregations in oocyst stage. This advanced technology allowed us to analyse the 3D details of organelle segregation inside the oocyst during sporogony formation. It was revealed that multiple nuclei were involved with several centrosomes in one germ nucleus during sporozoite budding (endopolygeny). Our high-resolution 3D analysis uncovered the endopolygeny-like nuclear architecture of Plasmodium in the definitive host. This nuclear segregation was different from that in the blood stage, and its similarity to other apicomplexan parasite nuclear divisions such as Sarcocystis is discussed.

Cranial-first approach of laparoscopic left colectomy for T4 descending colon cancer invading the Gerota's fascia

BACKGROUND

The safety and feasibility of laparoscopic colectomy for T4 colorectal cancer remain controversial. We believe that setting a "Goal" that will guide the surgeons in returning from the deep layer could be the key to safe en bloc resection of neighboring organs. For descending colon cancer, the cranial-first approach makes it possible to clearly visualize the pancreas and origin of the transverse mesocolon, leading to safe splenic flexure mobilization and complete mesocolic excision, which is the strongest advantage of this approach.

CASE PRESENTATION

A 75-year-old woman was diagnosed with T4 descending colon cancer invading the Gerota's fascia. We performed laparoscopic left colectomy using the cranial-first approach to set a "Goal" at the inferior border of the pancreas for safe resection of the Gerota's fascia. The total operative time was 233 min, and the estimated blood loss was 98 ml. She was discharged after surgery without postoperative complications. Pathological findings revealed the invasion into the Gerota's fascia, and the resection margin was negative for cancer.

CONCLUSIONS

The cranial-first approach of laparoscopic left colectomy appears to be safe and feasible and could be a promising method for selected patients with T4 descending colon cancer invading the Gerota's fascia.

P3764Morphological mechanisms of atrial functional mitral regurgitation in patients with atrial fibrillation

Background

Atrial functional mitral regurgitation (AFMR) occurs in patients with atrial fibrillation. However, morphological mechanisms of AFMR are poorly understood.

Purpose

The purpose of this study was to examine the morphological characteristics in patients with AFMR.

Methods

Among consecutive 795 patients undergoing initial radiofrequency catheter ablation (RFCA) at our hospital, twenty-five patients with persistent AF accompanied by AFMR (≥ moderate) before RFCA (AFMR group) were studied. Age-matched 25 patients with persistent AF without MR were defined as a control group.

Results

Left ventricular ejection fraction (LVEF) was lower and left atrium volume index was larger in the AFMR group (Table). Mitral valve annulus diameter and length of anterior mitral leaflet (AML) were similar between groups, whereas length of posterior mitral leaflet (PML) was significantly shorter in the AFMR group. Smaller tethering angle of AML (γ in the figure) and shorter tethering height were significantly associated with the occurrence of AFMR, which were different from morphology of functional mitral regurgitation in patients with dilated LV. Multiple regression analysis revealed that less tenting height (p<0.05) and LA dilatation toward the posterior (p<0.01) were significantly related to AFMR.

Echocardiographic parameters AFMR (n=25) Control (n=25) P value Age, y 69±8 66±10 NS Male, n (%) 9 (36) 20 (80) P=0.001 LVEF,% 60±9 67±6 P=0.004 LAD, mm 44±5 41±7 NS LAVI, ml/m2 56±17 41±13 P<0.001 MV diameter, mm 3.9±0.4 3.8±0.5 NS α angle, ° 34±9 35±7 NS β angle, ° 48±9 50±8 NS γ angle, ° 32±5 37±5 P=0.0005 AML length, mm 3.0±0.5 3.0±0.5 NS PML length, mm 2.1±0.1 2.4±0.1 P=0.03 Tenting height, mm 1.5±0.1 1.8±0.1 P=0.02 D, mm 0.8±0.3 0.5±0.3 P=0.001 LVEF: left ventricular ejection fraction; LAD: left atrial diameter; LAVI: left atrial volume index; AML: anterior mitral leaflet; PML: posterior mitral leaftlet.

Conclusions

AFMR occurs in patients with unique morphological features, such as less tethering height and LA dilatation toward the posterior.

P1025Clinical predictors for the improvement of left ventricular ejection fraction and prognosis after catheter ablation of atrial fibrillation in patients with systolic dysfunction

Background

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) and clinical outcomes in patients with left ventricular systolic dysfunction (LVSD). However, predictors of the improvement of LV function and clinical outcomes by CA were poorly understood.

Purpose

We examined the efficacy of CA in AF patients with LVSD and predictive factors associated with clinical outcomes.

Method

Among consecutive 795 patients undergone initial RFCA at our hospital, we studied 51 patients with LVSD (LVEF ≤50%). Improved LVEF more then 5% at 1-year after CA was classified as “responder” to CA. We analyzed clinical variables and echocardiographic parameters before and after the CAs.

Results

In the responder group, LVEF was significantly improved 1-year after catheter ablation compared with the non-responder group. (ΔLVEF 22±12% vs. −1±4%, p<0.001). The responder group was significantly younger, had more non-paroxysmal AF, smaller LV systolic diameter and lower plasma BNP level before CA (Table). Late gadolinium enhancement (LGE)-positive rate in cardiovascular magnetic resonance imaging (CMR) before CA was higher in the non-responder group than in the responder group (100% [6/6] vs. 38% [5/13], p<0.005). After CAs of AF, event-free survival from hospitalization for heart failure was significantly higher in the responder group (Figure) with less AF recurrence (27% vs. 47%, p=0.04) than in the non-responder group.

Baseline characteristics Responder (N=35) Non-Responder (N=16) P value Age, y 62±11 69±8 p<0.01 Male, n (%) 26 (74) 13 (76) NS Non-pAF 26 (74) 4 (24) p<0.01 LAD, mm 48±7 48±8 NS LAVI, ml/m2 54±17 58±20 NS LVDd, mm 54±7 58±10 NS LVDs, mm 43±7 48±10 p=0.05 EF, % 37±8 38±8 NS BNP (pg/ml) 278±225 684±848 p<0.05

Conclusion

Younger age, absence of LV dilatation, lower plasma BNP, or absence of LGE may well predict favorable clinical outcomes after CA in patients with LVSD.

Analysis of Environmental DNA and Edaphic Factors for the Detection of the Snail Intermediate Host Oncomelania hupensis quadrasi

BACKGROUND

The perpetuation of schistosomiasis japonica in the Philippines depends to a major extent on the persistence of its intermediate host Oncomelania hupensis quadrasi, an amphibious snail. While the malacological survey remains the method of choice in determining the contamination of the environment as evidenced by snails infected with schistosome larval stages, an emerging technology known as environmental DNA (eDNA) detection provides an alternative method. Previous reports showed that O. hupensis quadrasi eDNA could be detected in water, but no reports have been made on its detection in soil.

METHODS

This study, thus focused on the detection of O. hupensis quadrasi eDNA from soil samples collected from two selected schistosomiasis-endemic barangays in Gonzaga, Cagayan Valley using conventional and TaqMan-quantitative (qPCR) PCRs.

RESULTS

The results show that qPCR could better detect O. hupensis quadrasi eDNA in soil than the conventional method. In determining the possible distribution range of the snail, basic edaphic factors were measured and correlated with the presence of eDNA. The eDNA detection probability increases as the pH, phosphorous, zinc, copper, and potassium content increases, possibly indicating the conditions in the environment that favor the presence of the snails. A map was generated to show the probable extent of the distribution of the snails away from the body of the freshwater.

CONCLUSION

The information generated from this study could be used to determine snail habitats that could be possible hotspots of transmission and should, therefore, be targeted for snail control or be fenced off from human and animal contact or from the contamination of feces by being a dumping site for domestic wastes.

Graft Immunocomplex Capture Fluorescence Analysis Can Detect Intragraft Anti-Major Histocompatibility Complex Antibodies in Mice Cardiac Transplant

BACKGROUND

Immunocomplex capture fluorescence analysis has recently been applied as a method for detection of intragraft donor-specific anti-major histocompatibility complex (MHC) antibodies (DSA) in humans. Although intragraft DSA in humans is an intense topic of investigation, there is no report to assess intragraft DSA in murine organ transplantation.

METHODS

A model of presensitized mouse cardiac transplantation by donor splenocytes was used. To capture mouse MHC, anti-MHC class I/II antibodies were immobilized on Luminex beads. The MHC/DSA complexes were captured by the Luminex beads followed by detection of phycoerythrin-conjugated antimouse IgG antibodies where DSA had already reacted with the allograft in vivo.

RESULTS

Luminex beads were capable of detecting class I DSA in the cardiac allograft, though results for class II DSA were negative. Immunohistochemical investigation revealed that cardiac allografts had abundant MHC class I expression but only minor expression of MHC class II. Furthermore, MHC/class II DSA complexes were successfully detected in splenocytes and serum from a presensitized recipient.

CONCLUSIONS

These data suggested that graft immunocomplex capture fluorescence analysis can be also applied in murine cardiac transplantation. This novel application in mice would accelerate our comprehension of DSA through mechanistic studies.

Abstract P1-15-12: Axillary lymph node metastasis and HER2-receptor positivity significantly associate with recurrence and worse survival in breast cancer patients who achieved pathological complete response after neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NAC) has become a common practice in breast cancer care since it not only expands the opportunity for breast conservation surgery, but also allows in vivo assessment of individual cancer biology. Patients who achieved pathological complete response (pCR) after NAC are known to have significantly improved outcomes than those who did not. To date, there has been no large study of factors that associate with tumor recurrence after patients had pCR following NAC. To identify such factors, we examined a cohort of 394 patients.

METHODS

Patients diagnosed during 2007-16 with clinical stage I-III breast cancer who achieved pCR following NAC were identified from clinical records at four hospitals in urban Japan. Nearly 70% of patients received standard NAC regimen, which was a combination of anthracycline and taxane, with trastuzumab added as needed. pCR was defined as no pathological evidence of invasive cancer in the breast; residual ductal carcinoma in situ (DCIS) and residual axillary lymph node metastasis were included in this study. The median follow-up time was 63 months (range = 16-161 months). Outcomes were assessed by 5-year disease-free survival (DFS) and 5-year overall survival (OS).

RESULTS

Among the 394 patients with pCR, the breast cancer subtype was as follows: Luminal – 49 (12.4%), Luminal-HER2 – 97 (24.6%), HER2 – 117 (29.7%), and TNBC – 131 (33.2%). During follow up, 28 (7.1%) of the 394 patients had experienced tumor recurrence. In univariate Cox regression analysis, each of HER2-receptor status, pre-NAC tumor size, and pre-NAC axillary lymph node status were associated with recurrence. The hazard ratios, and their 95% confidence intervals (CI) and P values for these significant factors were as follows. HER2-receptor negative vs. positive: 2.5 (CI = 1.0-5.8; P = 0.036); cT1/2 vs. cT3/4: 2.2 (CI = 1.3-6.1; P = 0.008); cN0 vs. cN1-3: 9.5 (2.2-40.7; P = 0.002). However, age (&lt;50 vs. ≥50 y), residual DCIS, post-NAC axillary lymph node status, type of mastectomy (total vs. partial), and adjuvant radiation therapy were not associated with recurrence. Of the 28 patients with recurrence, site of first event was local for 8, and brain and visceral for 10 each. Seven of the 10 patients with brain metastasis were HER2-receptor positive. Eleven of the 28 patients with recurrence had deceased, with a median post-recurrence survival duration of 40 months (range = 2–94 months). Shorter survival was associated with HER2-receptor positivity (P = 0.003).

CONCLUSION

Axillary lymph node metastasis before rather than after NAC, and HER2-receptor positivity are associated with tumor recurrence in patients who achieved pCR in breast cancer. HER2-receptor positive patients had higher risk for brain metastasis and shorter survival. Given the extreme rarity of local recurrence after pCR, we cannot help but speculate that omitting surgical removal of pCR tissue may be permissible when pCR has been diagnosed accurately.

Citation Format: Asaoka M, Narui K, Suganuma N, Chishima T, Yamada A, Kawai S, Uenaka N, Sato E, Katsuta E, Kawaguchi T, Takabe K, Ishikawa T. Axillary lymph node metastasis and HER2-receptor positivity significantly associate with recurrence and worse survival in breast cancer patients who achieved pathological complete response after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-12.

Prevalence of human and non-human primate Plasmodium parasites in anopheline mosquitoes: a cross-sectional epidemiological study in Southern Vietnam

BACKGROUND

Human malaria is a major threat in rural communities of central Vietnam. Anopheles dirus and Anopheles minimus species are critical malaria vectors in Vietnam, which transmit Plasmodium parasites. However, the entomological aspects of malaria transmission in some of the central provinces of Vietnam remain unexplored. Hence, a cross-sectional entomological survey was carried out to identify the malaria vector species and the transmission of Plasmodium parasites in seven endemic provinces of Vietnam.

METHODS

Mosquitoes were collected from seven provinces, Gia Lai, Khanh Hoa, Phu Yen, Ninh Thuan, Binh Thuan, Dong Nai, and Binh Phuoc. The collection was conducted for four to eight consecutive nights using three established methods, indoor and outdoor human landing catches and light trap method. Nested-PCR analysis was performed to detect the Plasmodium species in the separated thorax and the abdomen of the individual mosquitoes.

RESULTS

A total of 2278 mosquitoes belonging to one of the four species of anopheline mosquitoes, An. dirus, An. maculatus, An. aconitus, and An. minimus were collected. Among the collected mosquitoes, 1398 were analysed using nested-PCR, of which, 40 mosquitoes were positive for Plasmodium parasites. Most of these parasites were detected in the samples from the thorax region, followed by the abdominal portion. The parasites were detected in both the thorax and abdomen of An. dirus. Seven species of Plasmodium parasites were detected during the analysis, of which, Plasmodium inui was the most common species, followed by Plasmodium falciparum, Plasmodium vivax, Plasmodium cynomolgi, Plasmodium coatneyi, Plasmodium knowlesi, and Plasmodium fieldi. Out of the 49 positive samples, 12 showed mixed infections. Co-infection of P. inui with human and other non-human primate Plasmodium species was common.

CONCLUSIONS

This study demonstrated the presence of human and non-human primate Plasmodium infection in An. dirus, a predominant malarial vector. Further, we showed that An. maculatus and An. minimus species also take part in malarial transmission. This might potentially lead to an alarming situation conducive for the emergence of novel zoonotic malaria.

Combination of PURE-DNA extraction and LAMP-DNA amplification methods for accurate malaria diagnosis on dried blood spots

BACKGROUND

Malaria is one of the most important parasitic infectious diseases for which almost half of the world's population is at risk. Although several diagnostic methods are now available to detect the infection, more sensitive and applicable tests are still required in the field. The loop-mediated isothermal amplification (LAMP) method is a DNA amplification tool in which the DNA amplification can be achieved by incubation at a stable temperature. A malaria detection kit based on this methodology has already been commercialized and is being used in some countries. The kit includes two reaction tubes: one targeting the common Plasmodium genus (Pan tube) and the other specifically targeting Plasmodium falciparum (Pf tube). In parallel, a simple DNA extraction method, the procedure for ultra rapid extraction (PURE), which can produce a DNA solution suitable for the LAMP reaction without the use of a centrifuge, has also become available. In this study, the sensitivity of the combination of the PURE and LAMP methods (PURE-LAMP) was evaluated with archived dried clinical blood samples of imported malaria cases, including P. falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae.

RESULTS

Using a nested PCR as the reference, 117 samples including 46 P. falciparum, 7 P. vivax, 9 P. ovale, 4 P. malariae, and 51 negative cases were tested. The PURE-LAMP Pan correctly identified 64 of the 66 positives and the 51 negatives. Among the Pan-positive samples 45 P. falciparum were also detected with the PURE-LAMP Pf. The PURE-LAMP Pan and PURE-LAMP Pf had respective sensitivities of 96.96% (95% CI 89.47-99.63) and 97.82% (95% CI 88.47-99.94) and common specificity of 1.

CONCLUSION

The PURE-LAMP system is accurate when used with dried blood spots and extendable to the field.

Human infection with Plasmodium knowlesi on the Laos-Vietnam border

Background

Border malaria in the Greater Mekong region of Southeast Asia poses a serious threat to the health of the ethnic minority populations of the region. Traditionally thought to be caused primarily by the malaria parasites Plasmodium falciparum and Plasmodium vivax, recently a zoonotic parasite, Plasmodium knowlesi, has been identified in some countries of the region. The presence of this parasite poses a challenge to malaria control programmes, as it is maintained in a zoonotic reservoir of forest-dwelling macaque monkeys.

Methods

A cross-sectional malaria parasite species prevalence survey was conducted along the Laos-Vietnam border in the central part of the two countries. Human blood samples were collected from Savannakhet in Laos and Quang Tri in Vietnam between August and October 2010 and assayed for the presence of human malaria parasite species and P. knowlesi. A PCR targeting the 18S small subunit ribosomal RNA gene and circumsporozoite protein gene was used for Plasmodium species identification.

Results

Nine cases of P. knowlesi were detected by PCR in blood samples from the Laos side and three from the Vietnam side. All P. knowlesi infections were found in co-infection with P. vivax, with some triple infections of P. knowlesi, P. vivax and P. falciparum detected in Laos. Phylogenetic analysis of these parasites suggests that P. knowlesi is circulating in the Laos-Vietnam border region.

Conclusion

This report shows that P. knowlesi is transmited on both sides of the Vietnam-Laos border. Continued monitoring of the range and prevalence of P. knowlesi on both the sides of Laos-Vietnam border is of importance to the National Malaria Control Programmes of both countries.

Electronic supplementary material

The online version of this article (10.1186/s41182-018-0116-7) contains supplementary material, which is available to authorized users.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Detection of the Plasmodium falciparum Kelch-13 gene P553L mutation in sporozoites isolated from mosquito salivary glands in South-Central Vietnam

Background

Plasmodium falciparum has developed resistance against artemisinin in Southeast Asia. Mutations in the P. falciparum Kelch-13 (Pfk13) gene are associated with artemisinin resistance in vitro and in vivo. We investigated the prevalence of mutations in PfK13 from sporozoite-stage parasites isolated from the salivary glands of Anopheles dirus mosquitoes.

Methods

Mosquitoes were caught by human-landing catches at two locations within the Khanh Phu commune, South-Central Vietnam. Identification of Anopheles species was performed based on morphological features and nucleotide sequence analysis. Sporozoite-infected salivary glands were stored on filter paper and at 4–6 °C. A nested-PCR targeting the small subunit ribosomal RNA gene was used for Plasmodium species identification. Pfk13 was amplified by nested PCR, and subjected to nucleotide sequencing.

Results

Five of 33 P. falciparum sporozoite samples carried the P553L mutation at the PfK13 locus. This mutation has been recorded previously in Vietnam, but not in Khanh Hoa province, were surveys of K13 polymorphism have not previously been carried out.

Conclusion

These results demonstrate the utility of mosquito-stage malaria parasite samples for studies on the molecular epidemiology of drug resistance.