99 Effect of application of seminal plasma on Day 0, 5, or 7 postmating on pregnancy rate and embryonic survival in alpacas (Lama pacos)

Alpacas, similar to other camelids, are classified as induced ovulators, as an external stimulus is required for the occurrence of ovulation. A protein identified as β-nerve growth factor, present in the seminal plasma (SP), has the capacity to induce ovulation and corpus luteum formation. Alpacas exhibit poor reproductive efficiency, with birth rates below 50% due in part to high embryo mortality before 35 days post-mating. A study was carried out to evaluate the effect of the application of SP on Day 0, 5, or 7 post-mating on pregnancy rate and embryo survival, defined as the difference in the numbers of pregnant females between Day 35 and 25. Nonpregnant adult alpaca females (n=124) between 5 to 6 years old were evaluated by transrectal ultrasonography to determine presence of a follicle ≥7mm, and then 2 days later to confirm permanence of the follicle. Alpacas were then bred by natural mating and assigned randomly to 1 of 4 treatments: 1mL of SP IM at mating; 1mL of SP IM Day 5 post-mating; 1mL of SP IM Day 7 post-mating; and control. Semen was collected from adults male and ejaculates were diluted 1:1 with PBS and then centrifuged for 30min at 3000 rpm. Supernatant was separated and a drop evaluated to determine absence of spermatozoa and SP-free sperm was stored at −20°C. Twenty adult males with optimal reproductive performance were used for mating with females assigned to the different treatments. Animals were evaluated by ultrasound with an Aloka SSD 500 (Aloka, Tokyo, Japan) and 5.0-MHz linear transducer on Day 25 and 35 to determine pregnancy rate and embryonic survival. Data were analysed by chi-square. Results are present in Table 1. The results differ from our initial hypothesis and a possible explanations may be that additional application of SP IM could saturate receptors and block the action of the seminal plasma present in the ejaculate of males. Table 1.Pregnancy rate and embryonic survival in alpacas with application of seminal plasma on Day 0, 5, or 7 Study was supported by project no. 405-PNICP-PIAP-UNMSM.

Selectivity Conversion of Protease Inhibitory Antibodies

Solid tumors are inherently difficult to treat because of large regions of hypoxia and are often chemotherapy- or radiotherapy-resistant. It seems that cancer stem cells reside in hypoxic and adjacent necrotic tumor areas. Therefore, new treatments that are highly selective for tumors and can eradicate cells in both hypoxic and necrotic tumor regions are desirable. Antibody α-radioconjugates couple an α-emitting radionuclide with the specificity of a tumor-targeting monoclonal antibody. The large mass and energy of α-particles result in radiation dose delivery within a smaller area independent of oxygen concentration, thus matching key criteria for killing hypoxic tumor cells. With advances in radionuclide production and chelation chemistry, α-radioconjugate therapy is regaining interest as a cancer therapy. Here, we will review current literature examining radioconjugate therapy specifically targeting necrotic and hypoxic tumor cells and outline how α-radioconjugate therapy could be used to treat tumor regions harboring more resistant cancer cell types.

Statement of Significance

Tumor-targeting antibodies are excellent vehicles for the delivery of toxic payloads directly to the tumor site. Tumor hypoxia and necrosis promote treatment recurrence, resistance, and metastasis. Targeting these areas with antibody α-radioconjugates would aid in overcoming treatment resistance.

Epitope-specific affinity maturation improved stability of potent protease inhibitory antibodies

Targeting effectual epitopes is essential for therapeutic antibodies to accomplish their desired biological functions. This study developed a competitive dual color fluorescence-activated cell sorting (FACS) to maturate a matrix metalloprotease 14 (MMP-14) inhibitory antibody. Epitope-specific screening was achieved by selection on MMP-14 during competition with N-terminal domain of tissue inhibitor of metalloproteinase-2 (TIMP-2) (nTIMP-2), a native inhibitor of MMP-14 binding strongly to its catalytic cleft. 3A2 variants with high potency, selectivity, and improved affinity and proteolytic stability were isolated from a random mutagenesis library. Binding kinetics indicated that the affinity improvements were mainly from slower dissociation rates. In vitro degradation tests suggested the isolated variants had half lives 6-11-fold longer than the wt. Inhibition kinetics suggested they were competitive inhibitors which showed excellent selectivity toward MMP-14 over highly homologous MMP-9. Alanine scanning revealed that they bound to the vicinity of MMP-14 catalytic cleft especially residues F204 and F260, suggesting that the desired epitope was maintained during maturation. When converted to immunoglobulin G, B3 showed 5.0 nM binding affinity and 6.5 nM inhibition potency with in vivo half-life of 4.6 days in mice. In addition to protease inhibitory antibodies, the competitive FACS described here can be applied for discovery and engineering biosimilars, and in general for other circumstances where epitope-specific modulation is needed.

Impact of the introduction of a nucleic acid amplification test for Clostridium difficile diagnosis on stool rejection policies

Background

The change from non-molecular to nucleic acid amplification tests (NAATs) is known to increase the detection of Clostridium difficile infection (CDI); however, the impact on stool rejection policies in clinical laboratories is unclear. The current guidelines have reinforced the importance of respecting strict conditions for performing tests on stool samples for CDI diagnosis. The purpose of this study was to estimate whether the implementation of molecular tests has resulted in changes in stool rejection policies between clinical laboratories that introduced NAATs and those that did not.

Results

A survey was conducted to evaluate the change in the number of stool samples rejected and the rejection criteria among 12 hospital laboratories in southwestern France before and after the switch from non-molecular tests to NAATs using retrospective data from June 1 till September 30, 2013 and the same period 2014. Four laboratories introduced NAATs as a second or third step in the process. A total of 1378 and 1297 stools samples were collected in 2013 and 2014, respectively. The mean number of rejected stool samples significantly increased (p < 0.001, Chi square test), with a total of 99 (7.1%) and 147 (11.3%) specimens rejected in 2013 and 2014, respectively. Notably, these laboratories had more stringent criteria and were no longer testing the stool samples of patients with CDI-positive results within 7 days. In contrast, there was a significant decrease in the rate of rejected stool samples (p < 0.001, Chi square test) in the five laboratories that did not adopt NAATs and a less stringent stool rejection policy.

Conclusion

Nucleic acid amplification test implementation improved compliance with recommended stool rejection policies. Laboratories should follow the recommended laboratory algorithm for the CDI diagnosis combined with the correct stool rejection policy.

Electronic supplementary material

The online version of this article (10.1186/s13099-018-0245-x) contains supplementary material, which is available to authorized users.

A Model for Estimation of the Pulmonary Capillary Pressure

To estimate the pulmonary capillary pressure, a theory was introduced by Holloway and coworkers. Based upon this, a mathematical model describing the measured data was developed. Because the physiologic data are embedded in noise and the pulmonary capillary pressure cannot be measured directly, we simulated an extensive series of data. The noise properties of the data were as analyzed to design a signal-processing tool, that cancels the noise from the measured data. The signal processing tool developed for the current application consists of pre-processing with a moving time average filter and post-processing with a neural network. After a verification procedure the tool can be applied to measured data, hence a more reliable measurement of the pulmonary capillary pressure is achieved.

[A case of gonococcal arthritis: Diagnostic difficulties and usefulness of synovial fluid PCR]

INTRODUCTION

The incidence of Neisseria gonorrhoeae septic arthritis remains low in the general population. Its clinical and microbiological diagnostic remains difficult.

CASE REPORT

We report a 44-year-old man who presented with a monoarthritis of the right ankle. The diagnosis of gonoccocal septic arthritis was obtained by PCR from the joint fluid. Treatment with ceftriaxone was effective.

CONCLUSION

In patients with high risk of N. gonorrhoeae infection, PCR for detection of gonorrhea in synovial fluid could potentially facilitate the diagnostic of gonococcal septic arthritis.

Defining the ultrasound longitudinal natural history of newly diagnosed pediatric small bowel Crohn disease treated with infliximab and infliximab-azathioprine combination therapy

BACKGROUND

Little is known about changes in the imaging appearances of the bowel and mesentery over time in either pediatric or adult patients with newly diagnosed small bowel Crohn disease treated with anti-tumor necrosis factor-alpha (anti-TNF-α) therapy.

OBJECTIVE

To define how bowel ultrasound findings change over time and correlate with laboratory inflammatory markers in children who have been newly diagnosed with pediatric small bowel Crohn disease and treated with infliximab.

MATERIALS AND METHODS

We included 28 pediatric patients treated with infliximab for newly diagnosed ileal Crohn disease who underwent bowel sonography prior to medical therapy and at approximately 2 weeks, 1 month, 3 months and 6 months after treatment initiation; these patients also had laboratory testing at baseline, 1 month and 6 months. We used linear mixed models to compare mean results between visits and evaluate whether ultrasound measurements changed over time. We used Spearman rank correlation to assess bivariate relationships.

RESULTS

Mean subject age was 15.3±2.2 years; 11 subjects were girls (39%). We observed decreases in mean length of disease involvement (12.0±5.4 vs. 9.1±5.3 cm, P=0.02), maximum bowel wall thickness (5.6±1.8 vs. 4.7±1.7 mm, P=0.02), bowel wall color Doppler signal (1.7±0.9 vs. 1.2±0.8, P=0.002) and mesenteric color Doppler signal (1.1±0.9 vs. 0.6±0.6, P=0.005) at approximately 2 weeks following the initiation of infliximab compared to baseline. All laboratory inflammatory markers decreased at 1 month (P-values<0.0001). There was strong correlation between bowel wall color Doppler signal and fecal calprotectin (ρ=0.710; P<0.0001). Linear mixed models confirmed that maximum bowel wall thickness (P=0.04), length of disease involvement (P=0.0002) and bowel wall color Doppler signal (P<0.0001) change over time in response to infliximab, when adjusted for age, sex, azathioprine therapy, scanning radiologist and baseline short pediatric Crohn's disease activity index score.

CONCLUSION

The ultrasound appearance of the bowel changes as early as 2 weeks after the initiation of infliximab therapy. There is strong correlation between bowel wall color Doppler signal and fecal calprotectin.