A Metalloproteinase Cocktail from the Venom of Protobothrops flavoviridis Cleaves Amyloid Beta Peptides at the α-Cleavage Site

A disintegrin and metalloproteinase (ADAM) family proteins are a major class of membrane-anchored multidomain proteinases that are responsible for the shedding of cell surface protein ectodomains, including amyloid precursor protein (APP). Human ADAM 9, 10, and 17 proteolyze APPs and produce non-amyloid-genic p3 peptides, instead of neurotoxic amyloid-β peptides (Aβs; Aβ40 and Aβ42), which form fibrils and accumulate in the brain of patients with Alzheimer's disease (AD). The ADAM family is closely related to snake venom metalloproteinases (SVMPs), which are derived from ancestral ADAMs but act as soluble proteinases. To test the therapeutic potential of SVMPs, we purified SVMPs from Protobothrops flavoviridis venom using metal ion affinity and pooled into a cocktail. Thus, 9 out of 11 SVMPs in the P. flavoviridis genome were identified in the cocktail. SVMPs inhibited Aβ secretion when added to human cell culture medium without affecting APP proteolysis. SVMPs degraded synthetic Aβ40 and Aβ42 peptides at the same cleavage site (α-site of APP) as ADAM9, 10, and 17. SVMPs did not degrade Aβ fibrils but interfered with their formation, assessed using thioflavin-T. Thus, SVMPs have therapeutic potential for AD as an Aβ-degrading protease, and the finding adds to the discovery of bioactive peptides from venoms as novel therapeutics.

Velocity pausing particle swarm optimization: a novel variant for global optimization

Particle swarm optimization (PSO) is one of the most well-regard metaheuristics with remarkable performance when solving diverse optimization problems. However, PSO faces two main problems that degrade its performance: slow convergence and local optima entrapment. In addition, the performance of this algorithm substantially degrades on high-dimensional problems. In the classical PSO, particles can move in each iteration with either slower or faster speed. This work proposes a novel idea called velocity pausing where particles in the proposed velocity pausing PSO (VPPSO) variant are supported by a third movement option that allows them to move with the same velocity as they did in the previous iteration. As a result, VPPSO has a higher potential to balance exploration and exploitation. To avoid the PSO premature convergence, VPPSO modifies the first term of the PSO velocity equation. In addition, the population of VPPSO is divided into two swarms to maintain diversity. The performance of VPPSO is validated on forty three benchmark functions and four real-world engineering problems. According to the Wilcoxon rank-sum and Friedman tests, VPPSO can significantly outperform seven prominent algorithms on most of the tested functions on both low- and high-dimensional cases. Due to its superior performance in solving complex high-dimensional problems, VPPSO can be applied to solve diverse real-world optimization problems. Moreover, the velocity pausing concept can be easily integrated with new or existing metaheuristic algorithms to enhance their performances. The Matlab code of VPPSO is available at: https://uk.mathworks.com/matlabcentral/fileexchange/119633-vppso.

Induced pathophysiological alterations by the venoms of the most dangerous Moroccan scorpions Androctonus mauretanicus and Buthus occitanus: A comparative pathophysiological and toxic-symptoms study

Scorpion envenomation is a serious public health issue. Androctonus mauretanicus (Am) and Buthus occitanus (Bo) are the most dangerous scorpions in Morocco. Despite their medical relevance, no study has yet related their kinetics of symptom apparition and the consequent tissue disorders at the same interval post-injection. This work achieved the first comparative pathophysiological and toxic-symptoms study between the Am and Bo venoms from a biochemical, toxicological and physiopathological standpoint. The activity of venoms and their subletal dose were determined by administration of increasing concentrations of the venoms. 30, 60 and 120 min following the experimental envenomation in mice, the profile of clinical symptoms was underlined and the main organs: brain, heart, lungs, liver and kidneys were removed for histological examination. The Am venom is a rich source of proteins and three-times more toxic than the Bo. The most observed clinical symptoms are neurological and cardiopulmonary. The Am venom caused histopathological alterations at 30, 60, and 120 min which were more important than the Bo. This study highlighted that both venoms exhibited a strong toxicity with variable intensities. Moreover, we showed the presence of correlation between the level of histopathological disorders observed and the intensity of signs appeared at the same time following venom inoculation.

Anti-Cancer Effect of Moroccan Cobra Naja haje Venom and Its Fractions against Hepatocellular Carcinoma in 3D Cell Culture

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in adults, the fifth most common malignancy worldwide and the third leading cause of cancer related death. An alternative to the surgical treatments and drugs, such as sorafenib, commonly used in medicine is necessary to overcome this public health problem. In this study, we determine the anticancer effect on HCC of Moroccan cobra Naja haje venom and its fraction obtained by gel filtration chromatography against Huh7.5 cancer cell line. Cells were grown together with WI38 human fibroblast cells, LX2 human hepatic stellate cell line, and human endothelial cells (HUVEC) in MCTS (multi-cellular tumor spheroids) models. The hepatotoxicity of venom and its fractions were also evaluated using the normal hepatocytes cell line (Fa2N-4 cells). Our results showed that an anti HCC activity of Moroccan cobra Naja haje venom and, more specifically, the F7 fraction of gel filtration chromatography exhibited the greatest anti-hepatocellular carcinoma effect by decreasing the size of MCTS. This effect is associated with a low toxicity against normal hepatocytes. These results strongly suggest that the F7 fraction of Moroccan cobra Naja haje venom obtained by gel filtration chromatography possesses the ability to inhibit cancer cells proliferation. More research is needed to identify the specific molecule(s) responsible for the anticancer effect and investigate their mechanism of action.

Mass spectrometry-based top-down and bottom-up approaches for proteomic analysis of the Moroccan Buthus occitanus scorpion venom

Buthus occitanus (B. occitanus) is one of the most dangerous scorpions in the world. Despite the involvement of B. occitanus scorpion in severe cases of envenomation in Morocco, no study has focused yet on the proteomic composition of the Moroccan B. occitanus scorpion venom. Mass spectrometry‐based proteomic techniques are commonly used in the study of scorpion venoms. The implementation of top‐down and bottom‐up approaches for proteomic analyses facilitates screening by allowing a global view of the structural aspects of such complex matrices. Here, we provide a partial overview of the venom of B. occitanus scorpion, in order to explore the diversity of its toxins and hereafter understand their effects. To this end, a combination of top‐down and bottom‐up approaches was applied using nano‐high liquid chromatography coupled to nano‐electrospray tandem mass spectrometry (nano‐LC‐ESI MS/MS). The LC‐MS results showed that B. occitanus venom contains around 200 molecular masses ranging from 1868 to 16 720 Da, the most representative of which are those between 5000 and 8000 Da. Interestingly, combined top‐down and bottom‐up LC‐MS/MS results allowed the identification of several toxins, which were mainly those acting on ion channels, including those targeting sodium (NaScTxs), potassium (KScTxs), chloride (ClScTxs), and calcium channels (CaScTx), as well as antimicrobial peptides (AMPs), amphipathic peptides, myotropic neuropeptides, and hypothetical secreted proteins. This study reveals the molecular diversity of B. occitanus scorpion venom and identifies components that may have useful pharmacological activities.

AB0582 DIAGNOSING SYSTEMIC SCLEROSIS WITH PHOTOACOUSTIC AND HIGH-FREQUENCY ULTRASOUND IMAGING

Background:

Vasculopathy is already evident in early systemic sclerosis (SSc); Raynaud’s phenomenon and typical nailfoldcapillaroscopic findings are part of the criteria of very early diagnosis of SSc (VEDOSs) (1). As not all early SSc patients have alterations in their nailfoldcapillaries, there is need for other diagnostic tools. Photoacoustics(PA) and high-frequency ultrasound (HFUS) might be able to fulfill this need (2). The former can measure the oxygen saturation of hemoglobin by using short pulsed laser light while the latter can provide high-resolution images that allow measuring skin thickening distal from DIP joint, which could be used to determine skin involvement early.

Objectives:

We hypothesize that photoacoustics and high-frequency ultrasound can distinguish (early) SSc patients from individuals with primary Raynaud’s phenomenon (PR) by measuring the oxygenation (by PA) of the fingertip and skin thickening (by HFUS).

Methods:

In our cross-sectional study, we compared measurements of the third finger in (early)SSc patients with individuals with PR and healthy volunteers. Smoking and beta-blockage were exclusion criteria. The level of oxygenation (by PA) and skin thickness (by HFUS) were compared between groups. Nailfoldcapillaroscopy was performed on all subjects and analyzed for the pattern.

Results:

Thirty-one adult subjects participated in this study: twelve patients with SSc, 5 patients with early SSc, 5 volunteers with PR and 9 healthy controls.

We found a significant difference in median (IQR) oxygen saturation between earlySSc patients 75.9% (IQR 75.1%-86.6%) and subjects with PR 94.1% (IQR 93.1%-94.5%) (p=0.0002) using the Wilcoxon rank-sum test (figure 1).

Figure 1.

Boxplot of saturation (%) per group.

Measurements of skin thickening also showed a significant difference in early SSc patients compared to subjects with PR, respectively 0.5mm (IQR 0.4mm-0.5mm) vs. 0.3mm (IQR 0.3mm-0.3mm), P=0.0002 (figure 2).

Figure 2.

Boxplot of skin thickness (mm) per group.

Conclusion:

Our results demonstrate that photoacoustic and high-frequency ultrasound can distinguish between (early)SSc and PR in both oxygenation saturation and skin thickening. In a larger prognostic study we want to determine the value of photoacoustic and high frequency ultrasound in diagnosing earlySSc.

References:

[1]Minier T, Guiducci S, Bellando-Randone S, Bruni C, Lepri G, Czirjak L, et al. Preliminary analysis of the very early diagnosis of systemic sclerosis (VEDOSS) EUSTAR multicentre study: evidence for puffy fingers as a pivotal sign for suspicion of systemic sclerosis. Annals of the rheumatic diseases. 2014;73(12):2087-93.

[2]Wang LV, Yao J. A practical guide to photoacoustic tomography in the life sciences. Nature methods. 2016;13(8):627-38

Disclosure of Interests:

Brigit Kersten: None declared, Khalid Daoudi: None declared, C.H.M. van den Ende: None declared, FHJ van den Hoogen Consultant of: AbbVie, Actelion, Biogen, BMS, Celltrion, Corbus, Eli-Lilly, Mundipharma, Pfizer, Sanofi-Genzyme, Speakers bureau: Amgen, Boehringer-Ingelheim, Novartis, CL de Korte: None declared, Madelon Vonk Grant/research support from: Janssen and Ferrer, Consultant of: Boehringer Ingelheim, Janssen and GSK, Speakers bureau: Boehringer Ingelheim, BMS and Roche

Consequences of Androctonus mauretanicus and Buthus occitanus scorpion venoms on electrolyte levels in rabbits

Androctonus mauretanicus (A. mauretanicus) and Buthus occitanus (B. occitanus) scorpions, which belong to the Buthidae family, are the most venomous scorpions in Morocco. For the first time, we investigated the effects of such scorpion venoms on serum electrolytes in subcutaneously injected rabbits. For this purpose, 3 groups of 6 albinos adult male rabbits (New Zealand) were used in this experiment. Two of the groups were given a single subcutaneous injection of either crude Am venom (5 μg/kg) or Bo venom (8 μg/kg) whereas the third group (control group) only received physiological saline solution (NaCl 0.9%). The blood samples were collected from injected rabbits via the marginal vein at time intervals of 30 min, 1 h, 2 h, 4 h, 6 h and 24 h after venom injection. The concentrations of electrolytes in the serum samples were measured. Our study indicates that scorpion envenomation in vivo, rabbit animal model, caused severe and persistent hypomagnesaemia and hypochloremia, which are accompanied of hypernatremia, hyperkalemia and hypercalcaemia. The intensity of electrolytes imbalance was clearly superior in the case of A. mauretanicus scorpion venom (although a lower quantity of venom was injected). This is coherent with the experimental data which indicate that A. mauretanicus venom is more toxic than B. occitanus venom.

Review of photoacoustic flow imaging: its current state and its promises

Flow imaging is an important method for quantification in many medical imaging modalities, with applications ranging from estimating wall shear rate to detecting angiogenesis. Modalities like ultrasound and optical coherence tomography both offer flow imaging capabilities, but suffer from low contrast to red blood cells and are sensitive to clutter artefacts. Photoacoustic imaging (PAI) is a relatively new field, with a recent interest in flow imaging. The recent enthusiasm for PA flow imaging is due to its intrinsic contrast to haemoglobin, which offers a new spin on existing methods of flow imaging, and some unique approaches in addition. This review article will delve into the research on photoacoustic flow imaging, explain the principles behind the many techniques and comment on their individual advantages and disadvantages.

Handheld probe integrating laser diode and ultrasound transducer array for ultrasound/photoacoustic dual modality imaging

Ultrasound and photoacoustics can be utilized as complementary imaging techniques to improve clinical diagnoses. Photoacoustics provides optical contrast and functional information while ultrasound provides structural and anatomical information. As of yet, photoacoustic imaging uses large and expensive systems, which limits their clinical application and makes the combination costly and impracticable. In this work we present and evaluate a compact and ergonomically designed handheld probe, connected to a portable ultrasound system for inexpensive, real-time dual-modality ultrasound/photoacoustic imaging. The probe integrates an ultrasound transducer array and a highly efficient diode stack laser emitting 130 ns pulses at 805 nm wavelength and a pulse energy of 0.56 mJ, with a high pulse repetition frequency of up to 10 kHz. The diodes are driven by a customized laser driver, which can be triggered externally with a high temporal stability necessary to synchronize the ultrasound detection and laser pulsing. The emitted beam is collimated with cylindrical micro-lenses and shaped using a diffractive optical element, delivering a homogenized rectangular light intensity distribution. The system performance was tested in vitro and in vivo by imaging a human finger joint.

Correcting photoacoustic signals for fluence variations using acousto-optic modulation

We present a theoretical concept which may lead to quantitative photoacoustic mapping of chromophore concentrations. The approach supposes a technique capable of tagging light in a well-defined tagging volume at a specific location deep in the medium. We derive a formula that expresses the local absorption coefficient inside a medium in terms of noninvasively measured quantities and experimental parameters and we validate the theory using Monte Carlo simulations. Furthermore, we performed an experiment to basically validate the concept as a strategy to correct for fluence variations in photoacoustics. In the experiment we exploit the possibility of acousto-optic modulation, using focused ultrasound, to tag photons. Results show that the variation in photoacoustic signals of absorbing insertions embedded at different depths in a phantom, caused by fluence variations of more than one order of magnitude, can be corrected for to an accuracy of 5%.

Changes in intraocular pressure after clear corneal phacoemulsification in normal patients

Purpose:

To evaluate changes in intraocular pressure (IOP) after clear corneal phacoemulsification (CCP) in normal patients.

Materials and Methods:

A prospective study including 273 normal patients selected for cataract extraction by CCP. Intraocular pressure was recorded on the 15^th day, l^st, 2^nd, 3^rd month and 6 months after surgery.

Statistical Analysis:

For statistical analysis, Epi Info was used to determine the statistical significance of changes in IOP.

Results:

The mean age of 96 women and 177 men was 71 ± 12 years. The mean IOP before surgery was 14.18 ± 3.4 mmHg. Our patients showed a mean decrease in IOP of 2.25 mmHg (16%) compared to preoperative values. Change in IOP was not related to lens thickness (P = 0.12), but significantly correlated with change in anterior chamber depth (ACD) (P = 0.002). The postoperative IOP was inversely related to preoperative ACD (P = 0.012). Age, sex and axial length were not significantly related to IOP reduction (P = 0.2–0.5)

Conclusion:

CCP was associated with a statistically significant reduction in IOP. The exact mechanism by which cataract surgery results in IOP reduction is unclear. CCP can be performed with the intent of achieving better IOP control.

Orbital osteoma: three case reports

INTRODUCTION

Osteoma is the most frequent benign tumor of paranasal sinuses. It is generally asymptomatic and usually discovered by chance during radiological imaging. Three cases with orbital extension are reported and discussed.

OBSERVATIONS

1st observation: Mrs. M.N. is an 18 years-old caucasian female who presented a stony orbital deformity associated with chronical dacryocystitis. Tomography of the orbit revealed a probable ethmoidal osteoma compressing the lacrimal canals. The management consisted in a surgical excision of the whole tumor by external approach, associated with a dacryocystorhinostomy. The patient's follow-up for the last 12 months was normal. 2nd observation: Miss K.A. is a 16 years-old caucasian female who came to consultation for a swelling of the medial angle of the left eye. Computed tomography images showed a fronto-ethmoidal process displaying a bone density consistent with an osteoma. The tumor was removed through an external ethmoidectomy. The patient was free of symptoms at 6 months follow-up. 3rd observation: Mrs. F. Z. is a 45 years-old patient who presented a 5 years history of right painful exophthalmos. The computed tomography was consistent with a fronto-ethmoidal osteoma with intraorbital extension near the optic nerve. The surgical excision was limited to the intraorbital portion. Postoperative complications included ptosis and diplopia.

DISCUSSION

Osteomas most commonly affect the fronto-ethmoid sinuses. They rarely show intraorbital extension or cause intracranial complications. They are generally asymptomatic. Symptoms are generally of late onset and are a consequence of tumoral growth and compression of neighbouring organs, as it is the case in our patients. Tumoral exophtalmos is the major ophthalmological sign. The computed tomography is of a great contribution, not only for diagnosis but also for the choice of the surgical approach. The classical surgical technique consists generally in a surgical excision of the osteoma. This surgery may induce ocular or neurochirurgical complications.

CONCLUSION

Osteomas of the paranasal sinuses are usually asymptomatic. If they become voluminous, they may cause orbital manifestations and serious complications. The rarity of ethmoidal osteoma with orbital growth made our cases interesting to report.

[Pseudoexfoliation syndrome in Moroccan patients with cataract scheduled for sugery]

PURPOSE

To evaluate the prevalence of pseudoexfoliation syndrome (PES) in Moroccan patients with age-related cataract scheduled for surgery.

PATIENTS AND METHODS

In a retrospective study, 837 consecutive eyes with age-related cataract scheduled for surgery were evaluated for the prevalence of PES, type of cataract, intraocular pressure (IOP) and operative complications.

RESULTS

Exfoliation material was detected in 82 patients (9.8 %). The mean age was 69.3 years with no sex predilection. The condition was unilateral in 44 cases (53.7%) and bilateral in 38 cases (46.3%). The prevalence of PES increased with age (p=0.02). Patients with hypermature cataract had significantly more PES (p <0.001). Mean IOP was significantly higher in eyes with PES (17.7 +/- 6.4 mmHg) than those without PES (14.3 +/- 2.9 mmHg) (p<0.001). Operative complications occurred more frequently in patients with PES: 14 (17 %) than in those without PES: 58 (6.9 %).

DISCUSSION

PES is a generalized degenerative fibrillopathy bound to age. The ethiopathogeny remains even unknown. The epidemiological data concerning the prevalence of the SPE in the African populations are scarce, and have not been published in Morocco, what motivated this study. Our study shows that this syndrome is common in Moroccan patients scheduled for cataract surgery with a prevalence of 9.8%. Its presence constitutes an important risk factor of primary open-angle glaucoma, and exposes more to peroperative complications at the time of surgery of cataract, independently of the technique used.

CONCLUSION

There is great variation in the prevalence of PES among people of different regions and ethnic groups, although many factors interfere in the comparative analysis of results, hence the interest to achieve other complementary epidemiological studies.

La sclérose tubéreuse de Bourneville

INTRODUCTION

Bourneville's tuberous sclerosis (BTS) is an autosomal dominant phakomatosis characterized by the development of a benign hamartoma-like tumor, which is usually located in the skin, kidney, heart, brain, and eyes. We present here a case of a retinal BTS of late diagnosis. We also discuss the clinical course and progress of this condition.

OBSERVATION

A 28-year-old man was a known BTS patient followed in the dermatology clinic. The ophthalmologic exam and the angiography with fluorescein revealed retinal astrocytic hamartomas bilaterally. Dermatologic examination also showed facial angiofibromas. The remainder of the physical examination was unremarkable. The chest X-ray, renal scan, heart scan and a CT scan of the brain failed to show any other localizations of the disease. The lesions described had remained unchanged over a period of 6 years.

CONCLUSION

Retinal lesions during BTS are dominated by the presence of astrocytic hamartomas essentially around the papillae. They are often an incidental diagnosis and evolve slowly. Except in complicated cases, their prognosis is usually satisfactory.

[Tyrosinemia type II. Case report]

Tyrosinemia type II or Richner-Hanhart syndrome is a rare hereditary disease characterized by the association of pseudoherpetiform corneal ulcerations and palmoplantar hyperkeratosis. We report the case of a 12 year-old young man presenting a superficial punctate keratitis and a corneal dystrophy in both eyes, associated with a palmoplantar hyperkeratosis. The dosage of the serum level of tyrosine is meaningfully raised to 1236 micromol/l. A dietary treatment restraining tyrosine and phenylalanine is started with favorable results after an evolution of 6 months. Tyrosinemia type II is an autosomal recessive disease, due to an enzymatic deficit in tyrosine aminotransferase. The diagnosis is based on the clinic and high level of serum and urinary tyrosine as well as of its urinary metabolites. This disease must be suspected in all cases of dentritic keratitis not reacting on the antiviral treatment, and more especially if it is associated with cutaneous lesions such as palmo-plantar keratosis.

[Marcus-Gunn Syndrome. Based on a case report]

The Marcus-Gunn syndrome associates an unilateral congenital blepharoptosis and "jaw-winking" synkinesia. We report a 12-year-old girl presenting an unilateral Marcus-Gunn syndrome and discuss the clinic, pathogenesis and treatment of this syndrome.

[Predictive factors of local recurrence of in situ intraductal carcinoma. Apropos of 217 cases]

The authors have reviewed 217 cases of pure intraductal carcinomas with a mean follow-up of 98 months (with 2 deaths out of 31 recurrences from which 35% into adenocarcinomas). The data concerning the diagnosis, the tumor size, the pathological type, the surgical treatment, more of less associated to radiation therapy are detailed. The aim of this work was to give a more reliable way or approaching the recurrence rate (31/217) to be able to apply a more conservative treatment to these cases. The lymph node dissection and removal seams to be useless in the in situ carcinomas. Concerning the tumor size, the local tumors can be treated by conservative surgical procedures and do not get any benefit from radiotherapy. The opposite is true concerning more largely invasive tumor. Concerning the histology, the non-comedocarcinomatous tumors get less benefit from radiotherapy than the comedocarcinomatous type. The study of the tumor limits and the reliquats seem to be useful. The treatment chosen and applied remains the major prognostic element in the probability of recurrence.

[Umbilical endometriosis. A case report]

Umbilical endometriosis is a rare site of the disease. The authors report a case of umbilical endometriosis only. Umbilical involvement is estimated at 0.5 to 1% of all site of the disease. This is a disorder affecting women of childbearing age, with a mean age of about 40. Medical treatment by progestogens or Danazol is inconstantly and partially effective regarding umbilical endometriosis. Surgical excision remains the only effective treatment: omphalectomy with wide removal of the tumor and reconstruction of an umbilicus. Surgery enables histologic study and, in the presence of suggestive symptomatology, search for and treatment of other genital sites.

[Monitoring of pregnancy in HIV seropositive women]

The management of pregnancy in a seropositive woman implies awareness of the effects of the disease on pregnancy and, inversely, of the pregnancy on HIV infection. It is important to be aware of the risk of materno-fetal transmission, as well as of the recent positive results of therapeutic trials of AZT during pregnancy regarding the prevention of such transmission. This quite stereotyped management approach is relatively simple, both clinically and regarding laboratory investigations, and in particular when the patient is at an asymptomatic stage of the disease. Obstetric management is, for the present, the same as in normal women. It is important to stress the need for specialised management of the newborn infant and of taking advantage of the postpartum period to ensure future effective contraception.

[Evaluation of risks of HIV transmission during medically assisted reproduction]

HIV transmission risks were specified during infertility treatment. An investigation was performed by gynecologists who work in IVF. Most of gynecologist refuse to treat infertility in these cases.