Management of cerebral venous thrombosis in Spain: MOTIVATE descriptive study

INTRODUCTION

Cerebral venous thrombosis (CVT) is an uncommon cause of stroke that mainly affects young adults. Early, accurate diagnosis can reduce the rate and severity of complications.

OBJECTIVE

The aim of this study was to analyse the clinical characteristics, management, and treatment of CVT in different centres in Spain.

METHODS

We conducted a multicentre, retrospective, descriptive study of patients hospitalised due to CVT between 2008 and 2017 at 10 Spanish centres.

RESULTS

We included 256 patients, with a mean age (SD) of 49.8 (18.7) years; 51% of patients were women. The most frequent symptoms were headache (73%), focal deficits (50%), epileptic seizures (33%), and encephalopathy (21%). The most frequent localisations were the superior sagittal sinus (12.5%), the transverse sinus (10.9%), and 2 or more sinuses or veins (66.4%). Thrombophilia was the most frequent known aetiology (24%), and was most commonly associated with the prothrombin G20210A mutation (19%). Forty-six percent of patients were treated with antithrombotics for 3 to 6 months, 21% for one year, and 22.6% required indefinite anticoagulation. Endovascular therapy was performed in 5% of cases, and 33% required neurosurgery. Regarding outcomes, 75% of patients were independent at 3 months (modified Rankin Scale [mRS] score ≤ 2), with papilloedema (P =  .03), focal deficits (P = .001), and encephalopathy (P < .001) showing a statistically significant association with poor prognosis (mRS > 3). The in-hospital mortality rate was 4.3%, with a 3-month mortality rate of 6.3%.

CONCLUSION

The diverse risk factors and variable presentation of CVT represent a challenge in the diagnosis and treatment of this condition. To improve prognosis and reduce mortality, it is essential to establish management protocols for this entity.

Diagnosis and treatment of disorders of intracranial pressure: consensus statement of the Spanish Society of Neurology's Headache Study Group

Primary intracranial pressure disorders include idiopathic intracranial hypertension and spontaneous intracranial hypotension. Remarkable advances have been made in the diagnosis and treatment of these 2entities in recent years. Therefore, the Spanish Society of Neurology's Headache Study Group (GECSEN) deemed it necessary to prepare this consensus statement, including diagnostic and therapeutic algorithms to facilitate and improve the management of these disorders in clinical practice. This document was created by a committee of experts belonging to GECSEN, and is based on a systematic review of the literature, incorporating the experience of the participants, and establishes practical recommendations with levels of evidence and grades of recommendation.

[New therapeutic era for migraine attacks with recently approved monoclonal antibodies, ditans and gepants]

Treatment of migraine attacks is advised in all patients, using non-steroidal anti-inflammatory drugs when the pain is mild and triptans when the pain intensity is moderate-severe. However, the effectiveness of these drugs is moderate, a high percentage of patients have side effects, and triptans are contraindicated in people with a history of stroke, ischaemic heart disease or poorly controlled hypertension. Hence, there is an urgent need for new therapeutic alternatives. In recent years, new drugs for migraine attacks have become available, most notably ditans (lasmiditan) and gepants (ubrogepant and rimegepant). Furthermore, eptinezumab, which has been approved for the preventive treatment of migraine in adults, has also been used for migraine attacks. This manuscript reviews the efficacy and safety results of the new drugs for migraines that will soon be on the market.

Telemedicine in the management of patients with headache: current situation and recommendations of the Spanish Society of Neurology's Headache Study Group

INTRODUCTION

The COVID-19 pandemic has caused an unexpected boost to telemedicine. We analyse the impact of the pandemic on telemedicine applied in Spanish headache consultations, review the literature, and issue recommendations for the implementation of telemedicine in consultations.

METHOD

The study comprised 3 phases: 1) review of the MEDLINE database since 1958 (first reported experience with telemedicine); 2) Google Forms survey sent to all members of the Spanish Society of Neurology's Headache Study Group (GECSEN); and 3) online consensus of GECSEN experts to issue recommendations for the implementation of telemedicine in Spain.

RESULTS

COVID-19 has increased waiting times for face-to-face consultations, increasing the use of all telemedicine modalities: landline telephone (from 75% before April 2020 to 97% after), mobile telephone (from 9% to 27%), e-mail (from 30% to 36%), and video consultation (from 3% to 21%). Neurologists are aware of the need to expand the availability of video consultations, which are clearly growing, and other e-health and m-health tools.

CONCLUSIONS

The GECSEN recommends and encourages all neurologists who assist patients with headaches to implement telemedicine resources, with the optimal objective of offering video consultation to patients under 60-65 years of age and telephone calls to older patients, although each case must be considered on an individual basis. Prior approval and advice must be sought from legal and IT services and the centre's management. Most patients with stable headache and/or neuralgia are eligible for telemedicine follow-up, after a first consultation that must always be held in person.

[Prognosis of patients assisted in the emergency unit by the 'TIA protocol' in a third-level hospital at 90 days]

INTRODUCTION

Care models developed for the rapid management of patients with transient ischaemic attack (TIA) are safe, effective and reduce recurrence rates. The aim is to determine the prevalence of cardiovascular events at 90 days.

PATIENTS AND METHODS

An observational, analytical, cross-sectional study was conducted. Adult male and female patients seen in the emergency department using the 'TIA protocol' between January 2016 and December 2019 were analysed. Data were collected on clinical variables, complementary tests, treatment and cardiovascular events (stroke/TIA, acute coronary syndrome or death due to cardiovascular causes) at 90 days. The study was approved by the Research Ethics Committee of Aragon.

RESULTS

The TIA protocol was performed on 163 out of 591 patients diagnosed with TIA in the emergency department. Brain CT and neurosonology scans were performed in 100% and a 24-hour Holter-electrocardiogram was carried out in 52.1%; atrial fibrillation (AF) was detected in 3.6% of them. An MRI brain scan was performed in 78.4% and acute ischaemic injury was seen in diffusion sequences (DWI+) in 13.5%. The prevalence of cardiovascular events at 90 days was 4.9% (8): stroke, 3.1% (five TIAs); acute coronary syndrome, 0.6% (one); and death from cardiovascular causes, 1.2% (two). Major adverse cardiovascular events were significantly associated with a history of ischaemic heart disease (p = 0.014). Cardiovascular death was associated with a history of AF (p = 0.008), anticoagulants at discharge (p = 0.007) and no antiplatelet therapy at discharge (p = 0.012), and there was a tendency towards an association with a history of type 2 diabetes mellitus (p = 0.05).

CONCLUSIONS

Rapid TIA protocols allow early care and avoid hospital admissions, without increasing the incidence of cardiovascular events or recurrence of stroke or TIA at 90 days.

Headache as a reason for consultation: the primary care perspective

INTRODUCTION

Headache is a frequent reason for consultation with primary care (PC) physicians. However, the condition is underdiagnosed and undertreated. One reason for this may be the lack of specific training on headache in PC.

METHODS

We conducted a descriptive cross-sectional study of data gathered with a self-administered survey that was completed by PC physicians from our health district. We collected sociodemographic data and information on previous training in neurology and headache, and training needs.

RESULTS

The survey was completed by 104 PC physicians, 53% of whom were women; mean age was 49 years. Most respondents worked in urban settings (42.3%) and had been trained via residency (77.9%). Although 65.4% spent more time with patients with headache than with other patients, only 32.7% used the International Classification of Headache Disorders. In our sample, 68.3% of respondents reported a high or very high interest in headache, and 75.9% wished to receive further training on the condition; theoretical and practical courses and update lectures were regarded as the most useful tools. In clinical practice, 90% used triptans and 78% used preventive treatments. The most frequently used drug was amitriptyline; only 22.1% choose topiramate.

CONCLUSIONS

PC physicians are in frequent contact with patients with headache and show interest in receiving training on this condition. This could be helpful in designing training programmes aimed at improving quality of care in this area.

Safety of anti-CGRP monoclonal antibodies in patients with migraine during the COVID-19 pandemic: Present and future implications

Background and objective

CGRP, a neuropeptide involved in migraine pathophysiology, is also known to play a role in the respiratory system and in immunological conditions such as sepsis. We analyzed the impact of the use of CGRP antagonists in patients with migraine during the COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus.

Methods

This is a multicentre cross-sectional study. From May to November 2020, through a national survey distributed by the Spanish Society of Neurology, we collected data about the presence of COVID-19 symptoms including headache and their characteristics and severity in patients with migraine treated with anti-CGRP monoclonal antibodies (mAb), and compared them with patients with migraine not receiving this treatment. We also conducted a subanalysis of patients with COVID-19 symptoms.

Results

We recruited 300 patients with migraine: 51.7% (155/300) were taking anti-CGRP mAbs; 87.3% were women (262/300). Mean age (standard deviation) was 47.1 years (11.6). Forty-one patients (13.7%) met diagnostic criteria for COVID-19, with no statistically significant difference between patients with and without anti-CGRP mAb treatment (16.1% vs 11.0%, respectively; P = .320). Of the patients with COVID-19, 48.8% (20/41) visited the emergency department and 12.2% (5/41) were hospitalised. Likewise, no clinical differences were found between the groups of patients with and without anti-CGRP mAb treatment.

Conclusion

Anti-CGRP mAbs may be safe in clinical practice, presenting no association with increased risk of COVID-19.

Management of cerebral venous thrombosis in Spain: MOTIVATE descriptive study

INTRODUCTION

Cerebral venous thrombosis (CVT) is an uncommon cause of stroke that mainly affects young adults. Early, accurate diagnosis can reduce the rate and severity of complications.

OBJECTIVE

The aim of this study was to analyse the clinical characteristics, management, and treatment of CVT in different centres in Spain.

METHODS

We conducted a multicentre, retrospective, descriptive study of patients hospitalised due to CVT between 2008 and 2017 at 11 Spanish centres.

RESULTS

We included 256 patients, with a mean age (SD) of 49.8 (18.7) years; 51% of patients were women. The most frequent symptoms were headache (73%), focal deficits (50%), epileptic seizures (33%), and encephalopathy (21%). The most frequent localisations were the superior sagittal sinus (12.5%), the transverse sinus (10.9%), and 2 or more sinuses or veins (66.4%). Thrombophilia was the most frequent known aetiology (24%), and was most commonly associated with the prothrombin G20210A mutation (19%). Forty-six percent of patients were treated with antithrombotics for 3-6 months, 21% for one year, and 22.6% required indefinite anticoagulation. Endovascular therapy was performed in 5% of cases, and 33% required neurosurgery. Regarding outcomes, 75% of patients were independent at 3 months (modified Rankin Scale [mRS] score ≤ 2), with papilloedema (P=.03), focal deficits (P=.001), and encephalopathy (P <.001) showing a statistically significant association with poor prognosis (mRS> 3). The in-hospital mortality rate was 4.3%, with a 3-month mortality rate of 6.3%.

CONCLUSION

The diverse risk factors and variable presentation of CVT represent a challenge in the diagnosis and treatment of this condition. To improve prognosis and reduce mortality, it is essential to establish management protocols for this entity.

Telemedicine in the management of patients with headache: current situation and recommendations of the Spanish Society of Neurology's Headache Study Group

INTRODUCTION

The COVID-19 pandemic has caused an unexpected boost to telemedicine. We analyse the impact of the pandemic on telemedicine applied in Spanish headache consultations, review the literature, and issue recommendations for the implementation of telemedicine in consultations.

METHOD

The study comprised 3 phases: 1) review of the MEDLINE database since 1958 (first reported experience with telemedicine); 2) Google Forms survey sent to all members of the Spanish Society of Neurology's Headache Study Group (GECSEN); and 3) online consensus of GECSEN experts to issue recommendations for the implementation of telemedicine in Spain.

RESULTS

COVID-19 has increased waiting times for face-to-face consultations, increasing the use of all telemedicine modalities: landline telephone (from 75% before April 2020 to 97% after), mobile telephone (from 9% to 27%), e-mail (from 30% to 36%), and video consultation (from 3% to 21%). Neurologists are aware of the need to expand the availability of video consultations, which are clearly growing, and other e-health and m-health tools.

CONCLUSIONS

The GECSEN recommends and encourages all neurologists who assist patients with headaches to implement telemedicine resources, with the optimal objective of offering video consultation to patients under 60-65 years of age and telephone calls to older patients, although each case must be considered on an individual basis. Prior approval and advice must be sought from legal and IT services and the centre's management. Most patients with stable headache and/or neuralgia are eligible for telemedicine follow-up, after a first consultation that must always be held in person.

Safety of anti-CGRP monoclonal antibodies in patients with migraine during the COVID-19 pandemic: Present and future implications

BACKGROUND AND OBJECTIVE

CGRP, a neuropeptide involved in migraine pathophysiology, is also known to play a role in the respiratory system and in immunological conditions such as sepsis. We analyzed the impact of the use of CGRP antagonists in patients with migraine during the COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus.

METHODS

This is a multicentre cross-sectional study. From May to November 2020, through a national survey distributed by the Spanish Society of Neurology, we collected data about the presence of COVID-19 symptoms including headache and their characteristics and severity in patients with migraine treated with anti-CGRP monoclonal antibodies (mAb), and compared them with patients with migraine not receiving this treatment. We also conducted a subanalysis of patients with COVID-19 symptoms.

RESULTS

We recruited 300 patients with migraine: 51.7% (155/300) were taking anti-CGRP mAbs; 87.3% were women (262/300). Mean age (standard deviation) was 47.1 years (11.6). Forty-one patients (13.7%) met diagnostic criteria for COVID-19, with no statistically significant difference between patients with and without anti-CGRP mAb treatment (16.1% vs 11.0%, respectively; P=.320). Of the patients with COVID-19, 48.8% (20/41) visited the emergency department and 12.2% (5/41) were hospitalised. Likewise, no clinical differences were found between the groups of patients with and without anti-CGRP mAb treatment.

CONCLUSION

Anti-CGRP mAbs may be safe in clinical practice, presenting no association with increased risk of COVID-19.

[Degree of compliance with treatment at three months in migraine patients]

INTRODUCTION

Adherence to oral preventive treatment (OPT) in migraine is often compromised. The aim was to determine the degree of adherence to OPT in migraine patients at three months.

PATIENTS AND METHODS

We conducted a multicentre observational study of patients diagnosed with episodic or chronic migraine (criteria of the International Headache Classification, third edition) in whom OPT was initiated. Demographic data (age, gender, educational level, marital status) and disease data (number of attacks, Headache Impact Test-6 and Migraine Disability Assessment Scale scores) were collected. At three months, the Morisky-Green scale was administered, which differentiates levels of adherence: excellent (0), moderate (1-2) and low (3-4).

RESULTS

Altogether 100 patients participated in the study: 87% women aged 42 ± 13 years, 14% with chronic migraine; 53.2% of them were beginning their first OPT. Beta-blockers were initiated in 23.2%, tricyclic antidepressants in 35.4%, flunarizine in 21.2%, neuromodulators in 19.2% and antihypertensives in 1%. Severe disability was observed in 56%, and the impact was very severe in 79.5%. Adhesion at three months was excellent in 41.8%, moderate in 28.6% and low in 29.6%. The most frequent reason for discontinuing was the occurrence of adverse effects (44%). A significant relationship was found between excellent adherence and being single (p = 0.046), and between low adherence and adverse effects (p = 0.009). No significant differences were found between the OPT used and the degree of adherence or the other variables studied.

CONCLUSIONS

Although our results are better than those published in the literature, we consider that therapeutic adherence in our setting is low and educating our patients in this regard is a priority.

Impact of the COVID-19 pandemic on headache management in Spain: an analysis of the current situation and future perspectives

Introduction

The COVID-19 pandemic has had a great impact on healthcare systems. Spain, where headache is the main reason for outpatient neurology consultation, is one of the countries with the most reported cases of the disease.

Objectives

This study aimed to analyse the impact of the COVID-19 pandemic on headache units in Spain and to evaluate how neurologists see the future of these units.

Methods

We conducted a cross-sectional online survey of headache units during the sixth week of the state of alarm declared in Spain in response to the pandemic.

Results

The response rate was 74%, with the participation of centres with different characteristics and from all Autonomous Communities of Spain. Limitations in face-to-face activity were reported by 95.8% of centres, with preferential face-to-face consultation being maintained in 60.4%, and urgent procedures in 45.8%. In 91.7% of centres, the cancelled face-to-face activity was replaced by telephone consultation. 95.8% of respondents stated that they would use personal protection equipment in the future, and 86% intended to increase the use of telemedicine. The majority foresaw an increase in waiting lists (93.8% for initial consultations, 89.6% for follow-up, and 89.4% for procedures) and a worse clinical situation for patients, but only 15% believed that their healthcare structures would be negatively affected in the future.

Conclusions

As a consequence of the pandemic, headache care and research activity has reduced considerably. This demonstrates the need for an increase in the availability of telemedicine in our centres in the near future.

[OnabotulinumtoxinA in the treatment of atypical odontalgia: description of a clinical case]

Atypical odontalgia (AO) is defined as a continuous dental pain in the area of one or several teeth, sometimes preceded by dental procedures in the absence of signs of dental pathology after complete examination. It is thought to have a neuropathic origin in which the response to local and systemic treatment is insufficient. We present the case of a 50-year-old patient with AO after dental extraction, who presented a significant reduction in pain after local treatment with OnabotulinumtoxinA (OnabotA) in the symptomatic area. The response to the administration of OnabotA in this patient is in line with what had previously been observed in small series of cases, so it could be a therapeutic alternative in this type of pain that is difficult to control.

Headache as a reason for consultation: the primary care perspective

INTRODUCTION

Headache is a frequent reason for consultation with primary care (PC) physicians. However, the condition is underdiagnosed and undertreated. One reason for this may be the lack of specific training on headache in PC.

METHODS

We conducted a descriptive cross-sectional study of data gathered with a self-administered survey that was completed by PC physicians from our health district. We collected sociodemographic data and information on previous training in neurology and headache, and training needs.

RESULTS

The survey was completed by 104 PC physicians, 53% of whom were women; mean age was 49 years. Most respondents worked in urban settings (42.3%) and had been trained via residency (77.9%). Although 65.4% spent more time with patients with headache than with other patients, only 32.7% used the International Classification of Headache Disorders. In our sample, 68.3% of respondents reported a high or very high interest in headache, and 75.9% wished to receive further training on the condition; theoretical and practical courses and update lectures were regarded as the most useful tools. In clinical practice, 90% used triptans and 78% used preventive treatments. The most frequently used drug was amitriptyline; only 22.1% choose topiramate.

CONCLUSIONS

PC physicians are in frequent contact with patients with headache and show interest in receiving training on this condition. This could be helpful in designing training programmes aimed at improving quality of care in this area.

Bioactive polymeric systems with platelet antiaggregating activity for the coating of vascular devices

The preparation, characterization, and analysis of physicochemical and biological properties of a new bioactive polymer system, based on a copolymer of an acrylic derivative of triflusal (a molecule with chemical structure related to aspirin with antiaggregating activity for platelets) is described and evaluated as thin bioactive coating for vascular grafts and coronary stents. The acrylic monomer derived from triflusal (THEMA) provides random copolymers when it is polymerized with butyl acrylate (BA), according to their reactivity ratios, r(THEMA) = 1.05 and r(BA) = 0.33. The copolymer THBA70, containing a molar composition f(THEMA) = 0.45 and f(BA) = 0.55 presents the optimal properties of stability, flexibility, and adhesion, with a T(g) = 21 ± 2 °C, to be applied as bioactive and biostable coatings for vascular grafts and coronary stents. Thin films of this copolymer system present an excellent biocompatibility and a good inherent antiaggregant activity for platelets.

Biocompatibility of alendronate-loaded acrylic cement for vertebroplasty

This paper reports a biological evaluation of a non-resorbable acrylic cement loaded with alendronate for the treatment of osteoporotic vertebral compression fractures. The cement formulation was based on polymethyl methacrylate and acrylic monomers; one of these had covalently linked vitamin E residues. The same cement in the absence of alendronate was used as a control. The setting of the charged cement presented a maximum polymerization temperature of 44°C, a setting time of 24 min, a residual monomer content lower than 3 wt.%, a compressive strength of 99±10 MPa and an elastic modulus of 1.2±0.2 GPa. Cytotoxicity studies using human osteoblast cultures revealed that the leachable substances of the alendronate loaded cement collected between 1 and 7 days decreased cell viability to values lower than 80%. However, morphological changes and cellular damage in cells produced by the extracts decreased with the leak time. Cell adhesion and growth on charged cement was significantly lower than on the control. Implantation of the cement paste in the intra-femoral cavity of rabbits showed that initially the osteogenic activity was evident for the cement charged with alendronate, and the osteosynthesis process took place mainly in the trabeculae and was manifested by the presence of a non-mineralised osseous spicule. The interface between material and adjacent bone tissue was initially characterized by a variable fibrous response that in many cases it appeared reduced to thin connective tissue after a 24-week-period.

Acrylic injectable and self-curing formulations for the local release of bisphosphonates in bone tissue

Two bisphosphonates (BPs), namely 1-hydroxy-2-[4-aminophenyl]ethane-1,1-diphosphonic acid (APBP) and 1-hydroxy-2-[3-indolyl]ethane-1,1-diphosphonic acid (IBP), have been synthesized and incorporated to acrylic injectable and self-curing formulations. Alendronic acid monosodium trihydrated salt (ALN) containing cement was formulated as control. These systems have potential applications in low density hard tissues affected by ailments characterized by a high osteoclastic resorption, i.e. osteoporosis and osteolysis. Values of curing parameters of APBP and IBP were acceptable to obtain pastes with enough fluency to be injected through a biopsy needle into the bone cavity. Working times ranged between 8 and 15 min and maximum temperature was around 50 degrees C. Cured systems stored for a month in synthetic body fluid had compressive strengths between 90 and 96 MPa and modulus between 1.2 and 1.3 GPa, which suggest mechanical stabilization after setting and in the short time. BPs were released in PBS at an initial rate depending on the corresponding chemical structure in the order ALN > APBP > IBP to give final concentrations in PBS of 2.21, 0.44, and 0.19 mol/mL for ALN, APBP, and IBP, respectively. Cytotoxicities of bisphosphonates were evaluated, IC(50) values being in the order APBP > ALN > IBP. Absence of cytotoxicity coming from leachables of the cured systems was observed in all cases independently of the BP. An improved cell growth and proliferation for the systems loaded with APBP and IBP compared with that loaded with ALN was observed, as assessed by measuring cell adhesion and proliferation, and total DNA content.

Assessment of natural and synthetic wollastonite as source for bioceramics preparation

Pseudowollastonite ceramics (beta-CaSiO3) from synthetic and natural sources were assessed with regard to their properties relevant to biomedical applications. Synthetic and natural CaSiO3 powders, with average particle size of 1.6 and 13.2 microm, respectively, were first employed. Powders were pressed and sintered at 1400 degrees C for 2 h. Pseudowollastonite was the only crystalline phase in sintered materials. Glassy phase, eight times more abundant in sintered natural wollastonite (SNW) than in the synthetic one (SSW), was observed in grain boundaries and in triple points. Larger grains and bigger and more abundant pores were present in SNW, resulting in lower diametral tensile strength (26 MPa), than in SSW (42 MPa). However, by milling the natural wollastonite starting powder to a particle size of 2.0 microm and sintering (SNW-M), the microstructure became finer and less porous, and diametral tensile strength increased (48 MPa). Weibull modulus of SNW and SNW-M samples was twice that of the SSW. All the samples released Si and Ca ions, and removed phosphate ions from simulated body fluid in similar amounts and were completely coated by apatite-like spherules after soaking in simulated body fluid for 3 wk. The aqueous extracts from all samples studied were not cytotoxic in a culture of human fibroblastic cells. No differences in fibroblast-like human cells adhesion and proliferation were observed between samples. According to the obtained results, properly processed pseudowollastonite bioceramics, obtained from the natural source, exhibit the same in vitro behavior and better performance in terms of strength and reliability than do the more expensive synthetic materials.

Acrylic bone cements with bismuth salicylate: Behavior in simulated physiological conditions

In a previous work, we reported the development of acrylic bone cement formulations for application in percutaneous vertebroplasty, by using bismuth salicylate (BS) as the radiopaque agent. Our objective was to obtain high radiopacity along with a therapeutical effect produced by the release of salicylic acid in situ. To follow that study, the setting kinetics and static and dynamical mechanical properties of the BS cements were studied in simulated physiological conditions. Moreover, radiopacity after various times of immersion in saline and the wettability of the cements surfaces were determined. The study finished with the analysis of the biological response. From the results, it can be concluded that physiological conditions did not affect negatively to the cements performance, since all BS-loaded cements fulfilled the ISO standard requirements. Radiopacity of the formulations was maintained over time and cements with BS were found to be biocompatible.

Injectable self-curing bioactive acrylic-glass composites charged with specific anti-inflammatory/analgesic agent

Injectable bioactive acrylic formulations based on poly(methyl methacrylate) (PMMA) and different amounts of bioactive glasses in the system SiO2-CaO-Na2O-P2O5 have been prepared in the presence of the anti-inflammatory analgesic drug fosfosal, the sodium salt of 2-phosphonoxibenzoic acid, to be used in minimally invasive surgery. The injectability of the formulations evaluated according to the established protocol was around 80%. The experimental formulations provided maximum temperatures in the range 50-60 degrees C, which were lower than those of commercial acrylic bone cements currently used in percutaneous vertebroplasty (PVP). Residual monomer content of any formulation was inferior to 5%. Compressive yield strength of dry specimens was in the range 80-95 MPa, but it decreased after immersion in SBF to values in the range 30-50 MPa, due to the dissolution of the bioactive glasses and the drug in the medium. The release of fosfosal was evaluated in vitro (pH = 7.0). The release profile against time obtained from a PMMA cement was quasi-linear and the 80% of the initial amount of drug was released in 175 h. However, for bioactive cements, the 80-100% of the fosfosal charged was released in approximately 48 h, due to the dissolution of the glasses in the medium. Values of weight loss of the cements determined gravimetrically ranged between 16% and 26% depending on the initial amount of fosfosal, i.e. 20 or 30 wt%, respectively. The weight loss and the water uptake were simultaneous processes, and values of hydration degree were around 10-14%. The formation of an apatite-like layer was detected on the surface of the cements at different periods of time depending on the composition of the bioactive glasses. The cements containing the glasses with P2O5 produced the growth of the apatite layer in shorter periods of time. The presence of fosfosal accelerated the precipitation of this layer independently on the glasses. The in vivo biocompatibility studied by intramuscular implantation in rats showed the absence of an anti-inflammatory response and a fibrous layer around the implant for the cement prepared with PMMA/fosfosal which is attributed to the therapeutic action of fosfosal acting in situ. The response to cements prepared with bioactive glasses and fosfosal showed a mild inflammatory reaction with the formation of the typical fibrous capsule around the implanted material.

Biocompatibility and other properties of acrylic bone cements prepared with antiseptic activators

Acrylic bone cements prepared with activators of reduced toxicity have been formulated with the aim of improving the biocompatibility of the final material. The activators used were N,N-dimethylaminobenzyl alcohol (DMOH) and 4,4'-dimethylamino benzydrol (BZN). The toxicity, cytotoxicity, and antiseptic action of these activators were first studied. DMOH and BZN presented LD50 values 3-4 times higher than DMT, were less cytotoxic against polymorphonuclear leucocytes, and possessed an antimicrobial character, with a high activity against the most representative microorganisms involved in postoperative infections. The properties of the acrylic bone cements formulated with DMOH and BZN were evaluated to determine the influence of these activators on the curing process and the physicochemical characteristics of the cements. A decrease of the peak temperature was observed for the curing with DMOH or BZN with respect to that of one commercially available formulation (CMW 3). However, residual monomer content and mechanical properties in tension and compression were comparable to those of CMW 3. The biocompatibility of acrylic bone cements containing DMOH or BZN was studied and compared with CMW 3. To that end, intramuscular and intraosseous implantation procedures were carried out and the results were obtained from the histological analysis of the surrounding tissues at different periods of time. Implantation of rods of cement into the dorsal muscle of rats showed the presence of a membrane of connective tissue, which increased in collagen fibers with time of implantation, for all formulations. The intraosseous implantation of the cements in the dough state in the femur of rabbits, revealed a higher and early osseous neoformation, with the presence of osteoid material surrounding the rest of the cured material, for the cement prepared with the activator BZN in comparison with that obtained following the implantation of the cement cured with DMOH or DMT (CMW 3).

Modulated release of cyclosporine from soluble vinyl pyrrolidone--hydroxyethyl methacrylate copolymer hydrogels. A correlation of 'in vitro' and 'in vivo' experiments

Soluble, uncrosslinked and high molecular weight copolymers of vinylpyrrolidone, VP, with 2-hydroxyethyl methacrylate, HEMA, prepared by free radical copolymerization, are proposed as supports for the modulated release of the immunosuppressor cyclosporine. Two copolymeric systems with copolymer compositions f(VP)=0.52 (namely VP--HEMA 60--40) and 0.42 (VP--HEMA 40--60) have been prepared and tested in vitro and in vivo using rats as animal model. Micellar electrokinetic capillary chromatography, MEKC, has been used for the simultaneous detection of the polymer reabsorption and the drug release for the in vitro experiments. The composition and microstructural distribution of the copolymer system controls the solubilization rate which modulates the in vitro release of the drug (with time profiles from a few days to several weeks for the VP--HEMA 60--40 and 40--60, respectively) and the in vivo response that correlates with the previous in vitro results: the more hydrophobic implant (VP--HEMA 40--60) reverts the immune response more slowly (2--4 weeks) compared to the more hydrophilic one (VP--HEMA 60--40, 1--2 weeks).

Hydrophilic polymers derived from vitamin E

Vitamin E containing copolymers for biomedical applications was obtained by copolymerization reaction of vitamin E methacrylate (VEMA) with 2-hydroxyethyl methacrylate (HEMA), N,N-dimethyl acrylamide (DMA) or vinyl pyrrolidone (VP), in different experiments. High molecular weight copolymers prepared by free radical reactions initiated by azobisisobutironitrilo, AIBN, present a random distribution of vitamin E derivatives along the macromolecular chains, and the average composition depends on the initial composition of the reaction medium. The relative flexibility of the polymeric systems was analyzed measuring the glass transition temperature of copolymeric sequences and that of the pure alternating diad (Tg12) obtained by the application of the treatments proposed by Johnston and Barton to all the systems. Tg12 was higher than the average T of both homopolymers (Tg) for the VEMA-HEMA system, Tg12 was lower than Tg for the VEMA-DMA system and Tg12 was similar to Tg for the VEMA-VP system. VEMA-HEMA copolymers gave rise to hydrogels in water, acidic and alkaline media. VEMA-DMA copolymers gave rise to hydrogels in acidic medium and dissolved in water and alkaline medium. VEMA-VP copolymers were soluble in all media. The swelling of all the hydrogels fit a second order kinetics. A VEMA-HEMA hydrogel was selected for in vivo experiments in order to study the influence of vitamin E on the regeneration process of Achilles tendon. The polymeric derivatives of vitamin E stimulated the regenerative process as a consequence of the antiaging effect in the local area of application.

Hydrophilic polymers derived from vitamin E

Vitamin E containing copolymers for biomedical applications were obtained by copolymerization reaction of vitamin E methacrylate (VEMA) with 2-hydroxyethyl methacrylate (HEMA), N,N-dimethyl acrylamide (DMA) or vinyl pyrrolidone (VP), in different experiments. High molecular weight copolymers prepared by free radical reactions initiated by azobisisobutironitrilo, AIBN, present a random distribution of vitamin E derivatives along the macromolecular chains, and the average composition depends on the initial composition of the reaction medium. The relative flexibility of the polymeric systems was analyzed measuring the glass transition temperature of copolymeric sequences and that of the pure alternating diad (Tg12) obtained by the application of the treatments proposed by Johnston and Barton to all the systems. Tg12 was higher than the average Tg of both homopolymers (Tg) for the VEMA-HEMA system, Tg12 was lower than Tg for the VEMA-DMA system and Tg12 was similar to Tg for the VEMA-VP system. VEMA-HEMA copolymers gave rise to hydrogels in water, acidic and alkaline media. VEMA-DMA copolymers gave rise to hydrogels in acidic medium and dissolved in water and alkaline medium. VEMA-VP copolymers were soluble in all media. The swelling of all the hydrogels fit a second-order kinetics. A VEMA-HEMA hydrogel was selected for in vivo experiments in order to study the influence of vitamin E on the regeneration process of Achilles tendon. The polymeric derivatives of vitamin E stimulated the regenerative process as a consequence of the antiaging effect in the local area of application.

Resorbable polyacrylic hydrogels derived from vitamin E and their application in the healing of tendons

A hydrogel containing vitamin E (alpha-tocopherol) was prepared by free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) and alpha-tocopheryl methacrylate (VEMA), the latter being synthesized previously to its use. The hydrogel containing 20 wt % of VEMA showed equilibrium water content in the range of those of hydrogel networks, at any pH. The swelling of the hydrogel followed Fick's law, indicating that sorption of water molecules is controlled by diffusion, although the values of diffusion coefficients for the VEMA-containing hydrogel were lower than those of poly-HEMA in any medium. Surface characterization of the VEMA-containing hydrogel revealed a decrease in the surface energy of solid owing to a decrease of the polar component mainly. The application of finely powdered xerogel of HEMA-VEMA copolymer bearing 20 wt % of the vitamin E derivative gave a very fast and positive response showing an activated regeneration capacity, probably due to the stimulation of the cellular proliferation or the more plausible effect, the cellular protection associated to the antioxidant properties of the vitamin E residue.

Duodenal leishmaniasis diagnosed by biopsy in two HIV-positive patients

We describe two cases of duodenal leishmaniasis in patients with human immunodeficiency virus (HIV) infection, diagnosed by light and electron microscopy. The patients presented nonspecific signs and symptoms, blood cultures were sterile, and serological tests for Leishmania spp. were negative. Endoscopy showed normal-appearing mucosa in one patient and possible peptic duodenitis in the other patient. In these patients, the parasite was only detected in a duodenal biopsy specimen. In view of the unusual location of the parasite and the fact that the diagnostic and dissemination of the disease was established by means of conventional biopsy, this is not a routine procedure for the diagnosis of leishmaniasis because the classic procedures require the demonstration of antibodies and visualization in bone marrow, lymph nodes, liver and/or spleen aspirates. We decided to report these two cases to call attention to the possible finding of Leishmania amastigotes in biopsies from intestinal mucosa in HIV infected patients.

Distribution of glyoxylate dehydrogenase activity in cortical and subcortical regions of the rat brain. A light microscopic histoenzymological study

The distribution of the glyoxylate dehydrogenase (GLYO-DH) (Glyoxylate oxidoreductase) activity has been investigated in rat brain using the corresponding histochemical method. The results have demonstrated a positive histochemical reaction in neurons of several cortical and subcortical areas. These neurons are located in the same regions in which operate monoaminergic neurotransmitters. These facts suggest a possible interaction between glyoxylic acid and monoaminergic neurotransmission.

Hepatic Morphological alterations induced by zidovudine (ZDV) in an experimental model

Zidovudine (AZT) inhibits HIV replication. Many studies have demonstrated its toxic myopathic effect in both HIV-positive patients treated with the drug and experimental animal models. So far hepatic lesions induced by AZT have not been reported. In our study, an experimental rat model was used in which the rats were administered AZT (1 mg/ml) in drinking water; histological and ultrastructural alterations were observed in the liver of treated animals and compared with the findings in control animals. The histological alterations detected were turbid swelling, vacuolar degeneration and microvacuolar fatty degeneration of panlobular distribution; these lesions were progressively greater as the duration of treatment increased. The ultrastructural alterations detected involved the mitochondria (similar to those described in cardiac muscle), smooth and rough endoplasmic reticulum (SER and RER), and the accumulation of fat and glycogen in the hepatocytes of treated animals. The histopathological and ultrastructural findings in our experimental model suggest hepatotoxicity induced by AZT or its catabolites in treated, as compared to control animals.

Diagnosis of genital infection caused by human papillomavirus using in situ hybridisation: the importance of the size of the biopsy specimen

AIM

To determine the size of a cervical biopsy specimen with human papillomavirus (HPV) infection required to enable in situ hybridisation to be carried out with a guarantee of a reliable result.

METHODS

In situ hybridisation was carried out in 142 cervical uterine biopsy specimens classified histologically as low grade and high grade squamous intraepithelial lesions. Epithelial length at the level of the basal membrane was measured by image analysis. The specimens were divided into 10 groups based on epithelial length.

RESULTS

Of the biopsy specimens, 61.2% were HPV positive. In specimens with an epithelial length below 5 mm 31.9% were HPV positive; in those between 5 and 9 mm in length 67.5% were HPV positive; and in those greater than 9 mm in length 81.8% were positive for HPV. For low grade squamous intraepithelial lesions (n = 90), 68.4% of specimens with an epithelial length greater than 5 mm were HPV positive. For high grade squamous intraepithelial lesions (n = 52), 86.8% of specimens with an epithelial length greater than 5 mm were HPV positive.

CONCLUSIONS

For a diagnosis of HPV infection using in situ hybridisation, the minimum length of epithelium in a cervical biopsy specimen should be 5 mm. For high grade squamous intraepithelial lesions, specimens over 5 mm in length are suitable. For low grade squamous intraepithelial lesions, to minimise the number of false negative results, the ideal minimum length is 10 mm.

Light and electron microscopic immunolocalization of L-asparaginase in the rat central nervous system

The investigation on the localization of L-asparaginase, the enzyme involved in the synthesis of L-aspartic acid, has been carried out using the immunohistochemical method. Antibodies against this enzyme were obtained immunizing BALB/c mice with purified Escherichia coli L-asparaginase. Light microscopic observation revealed positive immunoreactivity in the great majority of neurons and glial cells, and electron microscopic analysis demonstrated immunological localization of the enzyme in the cytosol. The ubiquitous distribution of L-asparaginase suggests its involvement in many important functions of the central nervous system.

Synaptic and non-synaptic immunolocalization of GABA and glutamate acid decarboxylase (GAD) in cerebellar cortex of rat

The existence of a large number of GABA receptors in the cerebellar molecular layer, and the observation of numerous punctate immunoreactive deposits of GABA synthesizing enzyme (GAD) throughout this layer, could indicate the existence of numerous axon terminals that may be involved in neurotransmission modulated by GABA. These axon terminals may be different from those considered classically as cerebellar GABAergic axon terminals. Therefore, we have reinvestigated the localization of GABA- and GAD-immunoreactivities in the cerebellar cortex of the rat with the PAP method, using different antisera obtained from rabbits immunized with GABA, baclofen and GAD. The results observed in our investigation have demonstrated GABA- and GAD-immunoreactivities in the axon terminals considered classically as GABAergic, as well as in others which, until now, have not been considered GABAergic. This fact leads us to think that the distribution of GABA or molecules structurally similar to GABA is far more extended than previously thought in the cerebellum. We have also observed both GABA- and GAD-immunoreactivities within dendrites and glial cells. These facts suggest us a possible extrasynaptic release of GABA.

[Trophic activity of neurotensin in massive intestinal resection]

Regulatory peptides are among the main factors affecting the proliferative adaptive process of the small bowel; its mechanisms of action remains unknown. An 80% small bowel resection was done in Wistar rats (250-300 g) randomly assigned to two groups: control and neurotensin (300 mu/kg). Jejunal and ileal samples were taken on day 14 post-resection and histomorphometric (villous length) and proliferative (DNA content) measures were obtained. Results show an increase in villous length in the neurotensin group but no changes in DNA content were observed. We conclude that neurotensin increases intestinal mucosal growth after massive intestinal resection in the rat.

[The effect of resection of the jejunum and ileum on intestinal mucosal trophism. An experimental study on the rat]

Intestinal resection leads to anatomo-physiological adaptive changes in the small bowel depending on its localization and extension. Two 50% resection models were done, jejunal resection (55 cm.) and ileal resection (55 cm.), in the attempt to determine the trophic response of the remnant bowel from jejunal and ileal samples. Significant increases were seen in mucosal villous length, jejunal values were greater than ileal and the greatest values were when the whole ileum was conserved. No significant changes were observed in DNA contents. These data suggest the importance of the ileal segment in the intestinal adaptive process, especially on the jejunal segment, as well as the apparent end of this response two weeks after resection.