Leptin mediates protective effects on the vasculature

Introduction and purpose

Lipodystrophy (LD) syndromes are characterized by the loss of adipose tissue resulting in metabolic complications and accelerated atherosclerosis. The systemic concentration of the adipokine leptin is reduced in LD as a result of adipose tissue deficiency. A therapeutical option to treat LD is the substitution of leptin, which improves metabolic complications and reduces mortality. However, the vascular effects of leptin remain largely unknown.

Here we analyze the direct effects of leptin on the vascular system and the development of atherosclerosis.

Methods and results

Treatment of human endothelial cells (ECs) with leptin reduced endothelial inflammation and the process of endothelial-to-mesenchymal transition (EndMT) (CNN1, −41.4%, p<0.05, n=4). In addition, leptin administration prevented the EndMT-induced increase of endothelial permeability. The protective effect of leptin on EndMT was confirmed in vivo in a combined lipodystrophic and atherosclerosis-prone mouse model (LDLR−/−; aP2-nSrebp1c). Treatment of the mice with leptin (3.0 mg/kg body weight daily for 8 weeks) decreased EndMT. Leptin showed no effect on plaques size but reduced the protrusion of plaques in atherosclerotic areas of the aortic roots (−31%, p<0.05, n=4–6).

Cytokine screening revealed an increase of the growth differentiation factor 15 (GDF15) in serum of LD patients (+26.2%, p<0.05, n=53–58) and in ECs after EndMT (+138%, p<0.05, n=6743–10920). This increase was reversed using leptin treatment in ECs undergoing EndMT, in the LD mice model, and in LD patients after 4 weeks of leptin administration. Indeed, treatment of endothelial cells with GDF15 induced EndMT (CNN1, +7.7-fold-control, p<0.05, n=3), and impaired EC barrier function. Neutralizing antibodies targeting GDF15 inhibited EndMT-mediated expression of mesenchymal genes (CNN1, −54%, p<0.05, n=4). The treatment of ECs with serum from LD patients induced EndMT and the increase of mesenchymal marker expression was inhibited with additional administration with neutralizing antibodies targeting GDF15 (CNN1, −28%, p<0.05, n=3).

Conclusion

Our findings indicate that EndMT is part of the cardiovascular disease progression in lipodystrophy syndromes. Leptin treatment has direct protective vascular effects by preventing inflammation, EndMT, and maintaining endothelial integrity.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)

Reduced RNA editing in the failing human heart mediates alternative circular RNA splicing

Background and purpose

Post-transcriptional RNA editing is an important mechanism in the development of human diseases. RNA editing can affect RNA stability and alternative splicing. The aim of our study was to characterize RNA editing and its impact on alternative RNA splicing in the healthy and failing human heart.

Methods and results

Human heart samples of heart failure (HF) patients (n=20) and controls (n=10) were analyzed using RNA sequencing with subsequent analysis of RNA editing. We identified adenosine-to-inosine (A-to-I) editing as the major form of RNA editing in human hearts, being reduced in HF patients. Consistently, we found the editing enzyme ADAR2 reduced in HF patients. A-to-I RNA editing predominantly occurred in intronic regions of protein-coding genes, specifically in repetitive, primate-specific Alu elements which can affect RNA splicing. Indeed, we found 173 circular RNAs (circRNAs) regulated by alternative mRNA splicing in the failing heart.

Loss of ADAR2 led to reduced RNA editing concomitant with an increase of circRNA, while overexpression reduced circRNA expression and enhanced RNA editing.

Conclusion

A-to-I editing is the major type of RNA editing in the human heart, being reduced in HF. We demonstrate a primate-specific alternative RNA splicing mechanism mediated by RNA editing in human hearts. The findings may be relevant to diseases with reduced RNA editing such as cancer, neurological and cardiac diseases.

Funding Acknowledgement

Type of funding sources: None.

Mood and suicidality amongst cyberbullied adolescents- a cross-sectional study from youth risk behavior survey

Introduction

There is a limited literature available showing mental health burden among adolescents following cyberbullying.

Objectives

Aim is to evaluate the association of low mood and suicidality amongst cyberbullied adolescents.

Methods

A study on CDC National Youth Risk Behavior Surveillance (YRBS) (1991-2017). Responses from adolescence related to cyberbullying and suicidality were evaluated. Chi-square and mix-effect multivariable logistic regression analysis was performed to find out the association of cyberbullying with sadness/hopelessness, suicide consideration, plan, and attempts.

Results

A total of 10,463 adolescents, 14.8% of adolescents faced cyberbullying a past year. There was a higher prevalence of cyberbullying in youths aged 15-17 years (25 vs 26 vs 23%), which included more females to males (68 vs 32%).(p<0.0001) Caucasians (53%) had the highest number of responses to being cyberbullied compared to Hispanics (24%), African Americans (11%).(p<0.0001) There was an increased prevalence of cyberbullied youths with feelings of sadness/hopelessness (59.6 vs 25.8%), higher numbers considering suicide (40.4 vs 13.2%), suicide plan (33.2 vs 10.8%), and multiple suicidal attempts in comparison to non-cyberbullied.(p<0.0001) On regression analysis, cyberbullied adolescence had a 155% higher chance of feeling sad and hopeless [aOR=2.55; 95%CI=2.39-2.72], considered suicide [1.52 (1.39-1.66)], and suicide plan [1.24 (1.13-1.36)].

Conclusions

In our study, cyberbullying was associated with negative mental health outcomes. Further research is warranted to examine the impact and outcomes of cyberbullying amongst adolescents and guiding the policies to mitigate the consequences.

Disclosure

No significant relationships.

Safety and efficacy of electrocautery scalpel utilization for skin opening in neurosurgery

Diathermy is used widely in neurosurgical procedures, mainly for subcutaneous and deeper layers dissection. The use on scalp and skin of other body parts has been precluded by the fear of scar formation and wound dehiscence. One-hundred-and-seventy-seven skin incisions for neurosurgical procedures have been performed using the micro-needle electrocautery scalpel (MES) and the steel scalpel. The elements in this study included: electrocautery generator unit, cutting mode, power, waveform, size and shape of the MES, depth of the incision, the speed of the electrode movement through tissue, amount of blood loss, physical inspection of the wound edges and wound complication. Patients tolerated the procedures well, with no increased risk from the use of the MES. Only two incisions had wound infection and dehiscence. All other patients had usual wound healing. Time taken during skin opening was significantly shorter when using the MES. Blood loss during skin opening was three to five times less when the micro-needle electrocautery scalpel was used. The MES is both safe and useful in neurosurgical procedures. The findings of this study recommend the use of the MES in all neurosurgical procedures, especially when blood loss has significant importance, such as in paediatric cases.

Extraosseous endolymphatic sac low-grade adenocarcinoma mimicking posterior fossa meningioma

Low-grade adenocarcinoma arising from the endolymphatic sac is an uncommon tumor that is characterized clinically by hearing loss and radiologically by temporal bone destruction. The authors report a case of low-grade adenocarcinoma of endolymphatic sac origin that mimicked a posterior fossa meningioma in both clinical and neuroimaging examinations. In this case, the most unusual and interesting feature was the lack of auditory symptoms and temporal bone destruction. The lesion occurred in a 21-year-old man who presented with headaches that had been increasing in frequency for 6 months and was associated with blurring of vision, diplopia, occasional nausea and vomiting, and gait disturbance. On examination, this patient exhibited bilateral papilledema, left sixth cranial nerve palsy, and gait ataxia. Neuroimaging studies revealed a large right posterior fossa tumor. At surgery, a hemorrhagic papillary adenocarcinoma of endolymphatic sac origin was found.

Cerebellar mutism caused by arteriovenous malformation of the vermis

Transient mutism following posterior fossa tumour resection in children is well known in the literature. To our Knowledge, this phenomenon has never been reported without surgical intervention. We report a case of cerebellar mutism secondary haemorrhage from a vermian arteriovenous malformation (AVM), which resolved to ataxic dysarthria after 6 weeks. Embolization of the AVM was performed and the patient's clinical status continued to improve gradually till she became normal 6 months from the insult. The mutism was due to rupture of the AVM which might correlate the cerebellar mutism with the transient vasospasm of the blood vessels supplying the cerebellum. It is possible for a spontaneus posterior fossa bleed to result in transient mutism similar to post surgical mutism.

Climbing the ladder: a step by step approach to international guidelines for water recycling

Given the pressures on the world's freshwater resources, recycled water is a valuable resource. Recycled water can increase the reliability of water supply because it is an independent source of water. Water recycling requires effective measures to protect public health and the environment. In the absence of comprehensive international guidelines, different countries have developed different approaches to managing water recycling depending on the understanding of the health risks, their individual economic circumstances, and affordability. Approaches vary between high technology/high cost/low risk and low technology/low cost/controlled risk. Furthermore, differences occur between countries and within individual countries. Inconsistencies can often be traced to lack of a unified scientific position on health effects. These inconsistencies increase public concerns about health risks and may give rise to conservative controls on responses to water recycling projects that some countries may be unable to afford. In this paper, an international panel of authors discusses how the different water recycling approaches might be linked together into international water recycling guidelines. These guidelines would incorporate a uniform approach to assessing hazards and risks while providing flexibility for individual countries to vary requirements to suit local circumstances of affordability and risk. The authors propose a framework of guidelines in which individual countries can progressively improve recycled water quality as lower risk levels become more affordable. The authors argue that a uniform international approach will result in a number of benefits including a better focus on risk management, better targeted research and development efforts and greater public confidence in water recycling. The authors invite discussion on the concepts put forward in the paper.

Surgical management of syringomyelia associated with spinal adhesive arachnoiditis

The authors describe a new surgical technique to minimise the postoperative recurrence of adhesion after microlysis of adhesion to treat syringomyelia associated with spinal adhesive arachnoiditis. A 47 year old male presented with numbness of the lower extremities and urinary disturbance and was demonstrated to have a case of syringomyelia from C1 to T2 which was thought to be secondary to adhesive spinal arachnoiditis related to a history of tuberculous meningitis. Following meticulous microlysis of the adhesions, maximal expansion of a blocked subarachnoid space was performed by expansive duraplasty with a Gore-Tex surgical membrane, expansive laminoplasty and multiple tenting sutures of the Gore-Tex graft. Postoperatively, the syringomyelia had be en completely obliterated and improvement of the symptoms had been also achieved. The technique described may contribute to improvement of the surgical outcome following arachnoid dissection by maintaining continuity of the reconstructed subarachnoid space.

A grading system for intracranial arteriovenous malformations applicable to endovascular procedures

SUMMARY

A grading system was designed by the first author (B.S.) specifically to predict the difficulty of endovascular obliteration of an intracranial arteriovenous malformation based on the feeding arterial characteristics, and the venous drainage system. We have retrospectively reviewed our cases of intracranial arteriovenous malformation, with special interest in those underwent endovascular embolization. The grading of the AVM was by either our new proposed system or by a surgically oriented grading system. Both systems were compared from the endovascular point of view.Using the present proposed grading system intracranial arteriovenous malformation may range from grade I to grade V. The difficulty of the endovascular embolization correlated well with the new grading system, while in most cases it did not reflect the degree of difficulty of the procedure when a pure surgical grading system was used. This newly designed grading system has a better prediction value to the difficulty of performing endovascular embolization than does other grading systems.

Intraparenchymal pericatheter cyst. A rare complication of ventriculoperitoneal shunt for hydrocephalus

Intraparenchymal pericatheter cyst is rarely reported. Obstruction in the ventriculoperitoneal shunt leads to recurrence of hydrocephalus, signs of raised intracranial pressure and possibly secondary complications. Blockage of the distal catheter can result, unusually, in cerebrospinal fluid oedema and/or intraparenchymal cyst around the ventricular catheter which may produce focal neurological deficit. We report two cases of distal catheter obstruction with formation of cysts causing local mass effect and neurological deficit. Both patients had their shunt system replaced, which led to resolution of the cyst and clinical improvement. One patient had endoscopic exploration of the cyst which confirmed the diagnosis made on imaging studies. Magnetic resonance imaging was more helpful than computed tomography in differentiating between oedema and collection of cystic fluid. Early recognition and treatment of pericatheter cyst in the presence of distal shunt obstruction can lead to complete resolution of symptoms and signs.

Contralateral approach to carotid cave aneurysms

BACKGROUND

To evaluate the surgical approach and clipping of aneurysms located at the carotid cave region.

METHOD

Between 1980 and 1998 we have adopted the well known ipsilateral approach for exposure and securing of carotid cave aneurysms. In four patients, we had the opportunity to use a contralateral approach to carotid cave aneurysms, with easier dissection and application of a simple aneurysmal clip. The visual acuity of the patients did not deteriorate from the pre-operative level.

FINDING AND INTERPRETATION

Aneurysms located at the carotid cave region may be approached easily and safely through a contralateral craniotomy with application of the aneurysm clip from an angle medial and inferior to the optic nerve.

Contralateral approach to junctional C2-C3 and proximal C4 aneurysms of the internal carotid artery: microsurgical anatomic study

OBJECTIVE

To evaluate a contralateral approach to aneurysms located in the internal carotid artery cave and proximal C4 segments.

METHODS

In six adult cadaveric head sides, proposed aneurysms in the carotid cave or proximal C4 segments were approached via contralateral craniotomies. We summarize the approach in the following steps: 1) frontotemporal orbital craniotomy, 2) drilling of the lateral sphenoid wing and opening of the dura along the frontotemporal base, 3) drilling of the planum sphenoidale and the tuberculum sellae more extensively toward the aneurysm side and opening of the sphenoid sinus, 4) drilling of the medial part of the anterior clinoid process on the side of the aneurysm and removal of the superior, medial, and inferior walls of the optic canal, 5) opening of the optic sleeve, and 6) opening of the space between the medial wall of the internal carotid artery C2-C3 segments and the lateral edge of the pituitary gland.

RESULTS

The contralateral approach to expose the opposite internal carotid artery cave and proximal C4 segments provided excellent views of the region, without mobilization or retraction of either the optic nerve or the carotid artery.

CONCLUSION

We recommend that this approach be used only for selected aneurysms, which are small and directed medially, anteriorly, or inferiorly, in the defined locations.

Osteoplastic laminotomy as a minimally invasive spinal procedure

A minimally invasive surgical technique is demonstrated to perform osteoplastic laminotomy. It consists of protection of the dural sac and the nerve roots with a rubber or silicone tube, cutting of the laminae with an oscillating saw and bilateral refixation of the laminae. This simple and safe technique, which has been used by the authors for six years, provides good stability of the spine postoperatively and helps to avoid post-laminectomy membrane formation.

Trochanteric osteotomy and wire fixation: a comparison of 2 techniques

Between 1986 and 1989, 190 patients (214 hips) with the diagnosis of osteoarthritis or posttraumatic arthritis underwent cemented Charnley total hip replacement surgeries via the biplane or single plane transtrochanteric approach. The technique of surgery was identical in every aspect except for the technique of the trochanteric osteotomy and reattachment. The results indicate that there was no significant difference in union rates between the 2 groups. Six (6.4%) patients in the biplane group and 7 (6.2%) patients in the single plane group had obvious evidence of nonunion at the 1-year evaluation. This study suggests no significant difference in union rate between a group of patients with biplane osteotomy and a closely paired group of patients with single plane osteotomy. Other equally important factors also may influence the rate of union of the trochanter in total hip arthroplasty.

Primary lymphoma of the central nervous system

Eleven patients with primary lymphoma of the central nervous system were seen in the King Faisal Specialist Hospital and Research Centre, Saudi Arabia, between 1986 and 1992. None had previously received immunosuppressive therapy. All cases were confirmed by biopsy and histopathological studies. Of the eleven patients, six had debulking of the tumour, seven received radiation therapy and six received chemotherapy. This report confirms the very poor prognosis for patients with primary lymphoma of the central nervous system, with only a few long-term survivors.

Lymph node metastasis in medulloblastoma

A 14-year-old boy was diagnosed as having a medulloblastoma in the posterior fossa. Radiation therapy was given and the patient made a good recovery. Three months later he presented with supraclavicular lymph node metastasis, in the absence of other foci of metastases. He was treated with 60Co and the metastasis decreased. Two months later a bone scan and bone marrow aspiration showed bone metastasis. He was started on chemotherapy. The different possible mechanisms of metastasis are discussed.