An unusual suspect for heart failure

A 71-year old retired missionary presented with a 2- week history of increasing dyspnoea, orthopnoea, and peripheral oedema. The patient had no previous significant past medical history. On clinical examination, his heart sounds were dual and his jugular venous pressure was elevated to 7cm. On chest auscultation there were bilateral crepitations at his lung bases.

An unusual suspect for heart failure

Constrictive pericarditis though an uncommon diagnosis is a potentially reversible form of heart failure (with surgical pericardiectomy) and hence is imperative to diagnose. Diagnosis is dependent on a high index of clinical suspicion and further testing with appropriate cardiac investigations including cardiac imaging with invasive cardiac catheterisation as the gold standard.

P374 Prediction of an adverse cardiovascular response to physical exercise from resting echocardiography imaging in young adults with suboptimal blood pressure

Funding Acknowledgements

British Heart Foundation (BHF) grants (PG/13/58/30397)

Background

Young adults with mildly elevated blood pressure are less likely to engage with physical activity. This may be because early hypertension alters myocardial response to moderate exercise, leading to greater perceived exertion and lower levels of enjoyment. As atrial and ventricular function are closely coupled we investigated whether subclinical atrial changes at rest may identify this myocardial response.

Purpose

To identify whether subclinical changes in left atrial function at rest predict response to exercise by performing left atrial deep-phenotyping in a cohort of young adults with a range of blood pressures.

Methods

Seventy-one full-term born young adults (25.25 ± 5.13 years) were enrolled in the Young Adult Cardiovascular Health sTudy (YACHT) to undergo baseline clinical and cardiovascular phenotyping including detailed blood pressure measurement. Cardiopulmonary exercise testing combined with echocardiography imaging was performed to assess the myocardial response to physical exercise at 40%, 60% and 80% of peak exercise load for all participants. Left ventricular ejection fraction and global longitudinal strain were measured from an apical four chamber view at each exercise load, and resting left atrial phasic function was assessed by conventional and speckle tracking echocardiography from apical four and two chamber views (figure 1).

Results

In this young cohort with a range of blood pressure (120.9 ± 12.96/70.85 ± 9.78 mmHg), resting left atrial reservoir and conduit function, but not left atrial structural measures, showed good correlation with left ventricular ejection fraction and global longitudinal strain during 40%, 60% and 80% of peak exercise. The association between resting left atrial conduit with left ventricular deformation at 60% of peak exercise intensity remained significant when adjusted for age, sex and mean arterial pressure (P = 0.007).

Conclusion

Left atrial phasic function at rest predicts left ventricular responses to physical exercise in this cohort of young adults, which may relate to early subclinical left atrial remodelling in early hypertension. These findings require validation in other cohorts and investigation of whether this exercise limitation can be overcome in young hypertensives.

Abstract P374 Figure 1

Association of Interleukin-31 gene polymorphisms with risk of cryptorchidism in a Chinese population

This study aims to investigate the possible association between Interleukin-31 (IL-31) gene polymorphisms and cryptorchidism risk.Two single nucleotide polymorphisms of IL-31, rs7977932 (C/G) and rs4758680 (C/A), were selected to be investigated in this study. Polymerase chain reaction-restriction fragment length polymorphism methods were used to discriminate the selected single nucleotide polymorphisms of IL-31 gene. A hospital-based case-control study of 112 cryptorchidism patients and 425 healthy controls was conducted.The frequencies of the C allele of rs4758680 in the patients with cryptorchidism were significantly higher compared with those in controls (89% vs 83%, P = .02, OR = 0.58, 95% CI = 0. 37-0.92). Compared with CC genotype in dominant model, notable decreased frequencies of A carriers (CA/AA genotypes) were observed in cryptorchidism patients (P = . 03, OR = 0.58, 95% CI = 0.35-0.96).Results demonstrated that IL-31 gene polymorphisms were associated with the genetic susceptibility to cryptorchidism in a Chinese population. Compared with CC genotype, the A carriers (CA/AA genotypes) of rs4758680 were protect factors in cryptorchidism susceptibility.

Graphene oxide-film-coated splitting ratio-adjustable Mach-Zehnder interferometer for relative humidity sensing

In this paper, a splitting ratio-adjustable Mach-Zehnder interferometer (MZI) for the measurement of relative humidity (RH) is proposed and experimentally demonstrated. The sensing head contains three sections of single mode fiber (SMF) and two sections of multimode fiber (MMF), in which the two MMFs are spliced among the three SMFs. The MMFs are corroded with hydrofluoric acid and act as mode couplers to split and recombine light owing to the core diameter mismatch with the SMF. A layer of graphene oxide (GO) is coated on the MMFs by dip-coating and natural evaporation. The effective refractive index of the GO will vary when it absorbs the water molecules. As a result, the intensity of the transmission light in the core and cladding of the single mode fiber can be adjusted. Thus, the intensity of the resonant dip will vary when the relative humidity changes. The experimental results show that a humidity sensitivity of 0.263 dB/RH% with a linear correlation coefficient of 99% can be achieved in a relative humidity range of 35% to 85%.

[A randomized single blind comparison of conventional bowel preparation and unplanned preoperative preparation for pelvic organ prolapse]

Objective: To investigate the influence of conventional preoperative intestinal preparation and unplanned preparation on the visual field of pelvic organ prolapse repair surgery. Methods: The patients who underwent transvaginal pelvic organ prolapse repair surgery in Peking University People's Hospital from September 2017 to July 2018 were selected as the research objects except those who had undergone colorectal surgery and chronic constipation. The surgery doctor was blinded by intestinal preparation. There was no intestinal preparation in non intestinal preparation group and polyethylene glycol was taken orally in intestinal preparation group. The main outcome measures were the effect of intestinal contents on the surgical field, the presence of fecal leakage, and the nature and volume of fecal leakage. The standard of fecal contamination was: mild, less than 15 ml, moderate, 15-30 ml, and severe, >30 ml. Secondary indicators were patient satisfaction and symptoms of routine bowel preparation. Results: A total of 120 patients (60 cases of non intestinal preparation group, 60 cases of intestinal preparation group) were selected, including transvaginal hysterectomy, vaginal anterior or posterior colporrhaphy (some patients with anterior prolapse repair with mesh), sacrospinal ligament suspension, total colpectomy and colpocleisis, laparoscopic sacral colpopexy, anti-incontinence surgery. The median age of the patients in non intestinal preparation group was 62 years, and the median age of intestinal preparation group was 60 years. There were no significant differences in median age, anesthesia, operation method, blood loss, operation time and perioperative infection between the two groups (all P>0.05). Fecal contamination occurred in 10% (6/60) of the patients without intestinal preparation and 32% (19/60) of the patients with intestinal preparation (P=0.042). Comparing the two groups, 10% (6/60) of the patients with intestinal preparation had moderate and severe contamination, and the patients without intestinal preparation was only 2% (1/60), there was significant difference (P=0.017). In intestinal preparation group, nausea (8%, 5/60), vomiting (5%, 3/60), abdominal distension (22%, 13/60), fatigue (5%, 3/60) and palpitation (2%, 1/60) were higher than those in non intestinal preparation group. Conclusions: Intestinal preparation with oral laxatives before pelvic organ prolapse repair surgery is not beneficial to the cleaning of the surgical field and increases the discomfort of intestinal preparation. It is safe and feasible for most patients with pelvic organ prolapse to perform pelvic organ prolapse repair surgery without intestinal preparation.

Abstract P4-08-32: Derivation and validation of a novel prediction model in breast phyllodes tumors after surgery

Aim

This study aimed to develop a nomogram based on clinicopathological features to evaluate the recurrence probability of breast phyllodes tumors following surgery. The criteria for atypia, mitoses, overgrowth, and surgical margin (AMOS) were also validated.

Method

Data from 334 patients with breast phyllodes tumors, who underwent surgical treatment at Sun Yat-sen Memorial Hospital from January 2005 to December 2014, were used to develop a prediction model. Additionally, data of 36 patients from Peking University Shenzhen Hospital and data of 140 patients from Sun Yat-sen University Cancer Center during the same period were used to validate the model. The medical records and tumor slides were retrospectively reviewed. The log-rank and Cox regression tests were used to develop a clinical prediction model of breast phyllodes tumors as well as validating the AMOS criteriaAll statistical analyses were performed using R and STATA.

Results

Of all 334 patients included in the study, 224 had benign, 91 had borderline, and 19 had malignant tumors. The local and distant recurrence rate was 17.7%. The 1-,3-, and 5-year cumulative recurrence-free survival was 98.5%, 97.9%, and 96.8%, respectively. Surgical margin, mitoses, and tumor border were identified as independent risk factors for breast phyllodes tumors. A nomogram was developed based on these three variables. The C-index of internal and external validation was 0.71and 0.67, respectively. The area under the curve of AMOS criteria was 0.59.

Conclusions

The present study model presented a more concise and objective variables to evaluate the recurrence-free survival of patients after surgery compared with that using the AMOS criteria, which is more appropriate for clinical practice and also allows for a more accurate prediction.

Citation Format: Song E, Chao X, Nie Y, Jin X, Tan C, Cui J, Hu H, Yao H. Derivation and validation of a novel prediction model in breast phyllodes tumors after surgery [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 P4-08-32.

Asp305Gly mutation improved the activity and stability of the styrene monooxygenase for efficient epoxide production in Pseudomonas putida KT2440

Background

Styrene monooxygenase (SMO) catalyzes the first step of aromatic alkene degradation yielding the corresponding epoxides. Because of its broad spectrum of substrates, the enzyme harbors a great potential for an application in medicine and chemical industries.

Results

In this study, we achieved higher enzymatic activity and better stability towards styrene by enlarging the ligand entrance tunnel and improving the hydrophobicity through error-prone PCR and site-saturation mutagenesis. It was found that Asp305 (D305) hindered the entrance of the FAD cofactor according to the model analysis. Therefore, substitution with amino acids possessing shorter side chains, like glycine, opened the entrance tunnel and resulted in up to 2.7 times higher activity compared to the wild-type enzyme. The half-lives of thermal inactivation for the variant D305G at 60 °C was 28.9 h compared to only 3.2 h of the wild type SMO. Moreover, overexpression of SMO in Pseudomonas putida KT2440 with NADH regeneration was carried out in order to improve biotransformation efficiency for epoxide production. A hexadecane/buffer (v/v) biphasic system was applied in order to minimize the inactivation effect of high substrate concentrations on the SMO enzyme. Finally, SMO activities of 190 U/g CDW were measured and a total amount of 20.5 mM (S)-styrene oxide were obtained after 8 h.

Conclusions

This study offers an alternative strategy for improved SMO expression and provides an efficient biocatalytic system for epoxide production via engineering the entrance tunnel of the enzyme’s active site.

Electronic supplementary material

The online version of this article (10.1186/s12934-019-1065-5) contains supplementary material, which is available to authorized users.