Bibliometric Analysis: Six Decades of Scientific Production from a Nationwide Institution: Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE) from Mexico

BACKGROUND

This study employed bibliometric analysis to ascertain the research focus areas among a group of Mexican physicians affiliated with the Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE). ISSSTE, a healthcare institution catering to a diverse range of diseases, offers a distinctive perspective on the investigated specialties within the realm of health. The primary objective was to identify knowledge gaps in medical care disciplines through a comprehensive examination of scholarly publications.

METHODS

We retrieved Scopus papers affiliated with "ISSSTE" and saved them as .CSV files. Subsequently, we employed VOSviewer, biblioshiny, and bibliometrix for bibliometric analysis. This enabled us to identify prominent institutions, prolific authors, highly cited researchers, and their respective affiliations.

RESULTS

Our analysis identified 2063 publications; the specialty internal medicine accounted for the greatest proportion with 831 publications. Original papers accounted for 82% of the total, with 52% of them being written in Spanish. The majority of scientific output, 92%, originated from Mexico City. The annual production has steadily increased since 2010, peaking in 2021 with over 200 publications. However, papers on prevalent conditions, such as metabolic syndrome, received limited citations, and the L0 index (percentage of uncited items) for all papers is close to 60%. Scopus mislabeled one affiliation, and some cases show a low paper-to-author ratio of 0.5 Discussion: Additional concerns, such as honorary authorship due to excessive authors per paper, and the underlying causes of low citation rates in Mexican publications, warrant further examination. Moreover, our research emphasizes the urgency of bolstering research and development funding, which was consistently below 0.5% of GDP for the past four decades, falling short of legal mandates and international benchmarks. We endorse the establishment of robust research collectives in Latin America to address these challenges, foster regional scientific output, and transition from knowledge consumers to knowledge producers, thereby reducing dependence on foreign technology.

The Role of an Exoskeleton Simulation of Senescence in Health Sciences Education

Background

Education in the formation of human capital in health constantly presents challenges. New tools in the emerging contexts may strengthen empathic attitudes. We developed an educational intervention that included a senescence simulator and assessed its impact on perception and attitudes in healthcare students.

Methods

A cross-sectional comparative study was conducted that assessed acquired knowledge and self-perception using a semistructured survey administered before and after the demonstration and intervention using the simulator and reported the experience through the role of the patient and caregiver. The data were analyzed statistically to identify the demographic characteristics and differences between the groups of students. The data were analyzed statistically to identify the demographic characteristics and differences between the groups of students in the responses pre-post intervention, using statistical software (IBM SPSS Statistics 26.0).

Results

Of the 256 participants surveyed before the intervention, 93.8% described cognitive deterioration as a significant disability and 53.1% considered the health system to be inadequate in meeting the needs of older individuals. Only 59.8% stated that the current academic training meets the educational requirements for the care of the elderly. In total, 98.9% of the participants reported that the simulator changed their perception by increasing their empathy. In total, 76.2% showed greater sensitivity to older adults and 79.3% reported that the experiential learning consolidated their professionalizing perspective. Among the younger participants (aged 18-20 years), sensitivity and reorientation toward pursuing an associated graduate degree were higher after the intervention (p=0.01).

Conclusions

Educational strategies, such as the senescence simulator, offer an experiential intervention that strengthens the knowledge and attitudes toward older individuals. During the pandemic emergency, it proved to be a useful educational strategy in consolidating caring behavior as a hybrid educational tactic. The senescence simulation enabled the participants to widen their educational and professional schemes to encompass the care of the older population.

Traumatic brain injury and the fall of the Aztec empire: 500 years of head injury diagnosis

BACKGROUND

The Aztec civilization has been one of the most powerful and organized cultures in the pre-Columbian era in America. Its fall was due to many factors, including the incursion of Spanish colonization and its violent transculturation, associated with the strong influence of its theological traditions and beliefs, which generated a new configuration in its social structure.

METHODS

Through a qualitative analysis and a systematic review based on the keywords Montezuma and TBI (Traumatic Brain Injury), we found 70 texts of interest, of which 32 were selected for their anthropological and medical content and their relationship with the history of neurosurgery.

RESULTS

The traumatic brain injury (TBI) controversy and its consequences on this leader's decision-making capacity and personal and social repercussions is evident. There are basically two versions of the story. That of the TBI was caused by his own people, and the other is the death due to injuries caused by the Spaniards. Historical texts that confirm these findings are presented.

CONCLUSION

There is documentary evidence of TBI in the Aztec emperor, which partly explains his decision making behavior in the face of the invading Europeans. However, there is no forensic evidence to determine the causes of his death.

Subsequent Curves of COVID-19 in Society

Beyond the strict biological scenarios inherent to the virus, other consequences exist that require attention due to the duration and evolving alternate implications of the pandemic in our society. The relevance of other "curves" in the Covid-19 Pandemic, related with Non Covid diseases, socio-economic issues, the wear and tear on the medical and social service infrastructure, and the physical and mental deterioration in the human resources, need a special focus in the global strategies in the management of Covid-19 pandemic. Civil rights and legal implications, are another issue to have in mind in the decisions, because these guidelines must not be the cause of social discrimination or stigma in the society. This bioethics approach is particularly targeted to those who are primarily responsible for decision making in matters with an impact on public health.

Bilaminar Chitosan Scaffold for Sellar Floor Repair in Transsphenoidal Surgery

Background

Endoscopic endonasal transsphenoidal surgery (EETS) is a standard technique used to approach sellar tumors. It is relatively safe, minimally invasive and carries a low risk of complications. However, one of the common complications reported with this technique is CSF leakage which causes morbidity, an increase in recovery time and hospital costs. This complication usually occurs from violation of the diaphragma sellae and a defect in the structures of the sellar floor or incomplete repair. In this article we report the first case with the use of a novel bilaminar chitosan scaffold which can be potentially used in the repair of the sellar floor, primarily aiming to the bony part of this structure.

Case Presentation

After a personalized design employing a tissue engineering strategy, we reconstructed the sellar floor in a 65-year-old woman who had undergone EETS for a pituitary adenoma with progressive bilateral visual loss. To repair the bony defect of the sellar floor, we used a novel bilaminar chitosan scaffold. The patient had an unremarkable postoperative course with no evidence of CSF leak. The polymer was well tolerated without toxicity, infection or complications. After 2 years of follow up the patient remains neurologically intact, and in good endocrinological status.

Conclusion

This is the first report of the use of this biomaterial and its biocompatibility in a clinical setting for the repair of the sellar floor during EETS. Our experience with chitosan bilaminar scaffold and in several preclinical studies in the literature have demonstrated good biocompatibility and effective bioengineered bone regeneration due to its excellent osteoconductive properties, this study pretends to be one landmark for further clinical research and larger case series with the use of this personalized tissue engineering materials in order to see they real efficacy to increase the surgeon armamentarium.

Chitosan-Hydroxyapatite Scaffold for Tissue Engineering in Experimental Lumbar Laminectomy and Posterolateral Spinal Fusion in Wistar Rats

Study Design

Experimental study with an animal model.

Purpose

To evaluate the role of a chitosan and hydroxyapatite composite for spinal fusion in a lumbar experimental model based on regenerative tissue engineering principles.

Overview of Literature

Chitosan and hydroxyapatite represent an alternative biodegradable implant material for tissue engineering and regeneration. The combination of chitosan and hydroxyapatite in a 20:80 ratio could potentiate their individual properties as an implantable composite for experimental laminectomy.

Methods

Phase I: design and synthesis of a porous composite scaffold composed of chitosan-hydroxyapatite using a freeze drying technique. Phase II: experimental microsurgical lumbar laminectomy at L5. A total of 35 Wistar rats were categorized into three experimental groups: control (laminectomy alone), experimental (laminectomy with implant), and reference (intact spine) (n=5 per group). Postoperative structural and functional evaluations were performed using computed tomography scans. In addition, radiologic, clinical, histological, and immunohistochemical microstructures were evaluated.

Results

At the laminectomy site, the composite implant induced bone regeneration, which was observed in the axial reconstruction of the rat lumbar spine in all cases. Biomechanical changes in the lumbar spine were observed by radiology in both groups after the surgery. The posterolateral space was covered by a bone structure in the treated spine, a condition not seen in the control group. The range of motion was 7.662°±0.81° in the scaffold group versus 20.72°±3.47° in the control group. Histological findings revealed qualitatively more bone tissue formation in the implant group.

Conclusions

A composite of chitosan-hydroxyapatite at a 20:80 ratio induced bone formation after experimental laminectomy in rats and led to spinal fusion, which was assessed by radiology and biomechanical tests. No functional complications in posture or walking were observed at 90 days post-surgery, despite biomechanical changes in the spine.

Strategies in Traumatic Brain Injury and Alcohol Consumption: A Professional's Survey

BACKGROUND

Traumatic brain injury associated with alcohol consumption is a global public health problem. It is important to identify and rethink the strategies to approach this challenge for health care institutions from a professional perspective.

METHODS

An online survey, created with Google Forms, was sent to professional neurosurgeons in Mexico and Latin America. Participation was voluntary, and responses were anonymous and confidential. Data were captured after 1 month and subjected to descriptive statistical analysis using Fisher exact and χ² tests.

RESULTS

There were 83 questionnaires answered by certified neurosurgeons with a response rate of 52.9%. Responses indicated that 78% of hospitals have no specific management guidelines for patients with TBI and alcohol intoxication. In 90% of cases, no triage strategies are defined for the case, and at hospital admission, there are no specific identified strategies for extraordinary surveillance of risks in these patients (P = 0.062).

CONCLUSIONS

These findings confirm a lack of systematic strategies for management of patients with TBI and associated comorbidity of alcohol intoxication in the acute phase. It is important to define specific management guidelines to improve treatment efficacy and limit complications in patients with TBI and alcohol intoxication.

Paradoxical Herniation in the Postcraniectomy Syndrome: Report and Literature Update

Introduction The decompressive craniectomy is a surgical strategy widely used with specific criteria to control the refractory intracranial pressure (ICP). However, it is important to warn about the presence of a postcraniectomy syndrome and analyze the risk-benefit on a long term. Case Report A 72-year-old male patient diagnosed with a subarachnoid hemorrhage secondary to the rupture of an anterior circulation aneurysm that develops vasospasm, secondary ischemia, and edema with signs of herniation that required a decompressive craniectomy on a first step. Afterwards, the aneurysm was approached and he consequently developed hydrocephaly. A ventriculoperitoneal shunt is installed, contralateral to the craniectomy, and progressive sinking of the skin flap, there is neurological deterioration and paradoxical herniation. Its association with the clinical deterioration by bronchoaspiration did not allow the cranioplasty to resolve the ICP decompensation. Conclusions The paradoxical herniation as part of the postcraniectomy syndrome is an increasingly common condition identified in adult patients with cortical atrophy, and who have also been treated with ventricular shunt systems. Timely cranioplasty represents the ideal therapeutic plan once the compromise from the mass effect has resolved to avoid complications derived from the decompressive craniectomy per se.

Neurofibromatosis type 1 and pregnancy: The transformation of a nodular to cystic neurofibroma in the cervical region

Background:

The peripheral hallmarks of neurofibromatosis type 1 (NF1) are Café au lait and solid nodular neurofibromas. The morphological behavior of these lesions could be susceptible to modification during pregnancy. The present case report describes a case of cystic transformation of a nodular neurofibroma, with progressive growth and mass effect in the anterior cervical region, which was surgically resolved without any complications.

Case Description:

A 33-year-old female patient with a known personal history of NF1, with annual control of the peripheral neurofibromas and cerebral and spinal magnetic resonance imaging follow-ups. Under genetic counseling, she decides to get pregnant following all the medical advises. Once the pregnancy is confirmed, she starts to notice the growth of one of them adjacent to the left cervical region. Such neurofibroma presented with the progressive gradual increase and in the last month, she presented dysphagia, dysphonia, and postural pain localized by the mass effect. Once the pregnancy concluded, the microsurgical approach was scheduled for resection of the lesion, where a cystic mass was found within the walls of the neurofibroma. The resection was uneventful.

Conclusion:

The transformation of a nodular to cystic neurofibroma during pregnancy is a very rare presentation, which may exacerbate the clinical symptomatology depending on the topography of the lesion due to the mass effect it may create. This condition may alert to the recommendations and vigilance in patients with NF1, who are pregnant or are planning on a future pregnancy. The neurosurgical resolution in this region is safe and beneficial.

A microsurgical anterior cervical approach and the immediate impact of mechanical retractors: A case control study

Introduction:

A microsurgical anterior cervical approach with discectomy and fusion (MACDF) is one of the most widely used procedures for treating radicular disorders. This approach is highly successful; however, it is not free from complications. These can be associated with soft tissue injuries.

Aim of the Study:

The recognition of the risks for these complications should be identified for timely prevention and safe treatment.

Materials and Methods:

Study Design: Retrospective case control study. This study includes a retrospective case series of 37 patients, paying special attention to immediate complications related to the use of mechanical retraction of soft tissue (dysphagia, dysphonia, esophageal lesions and local hematoma); and a comparative analysis of the outcomes after changes in the retraction method.

Results:

All selected cases had a positive neurological symptom response in relation to neuropathic pain. Dysphagia and dysphonia were found during the first 72 h in 94.1% of the cases in which automatic mechanical retraction was used for more than one hour during the surgical procedure. A radical change was noted in the reduction of the symptoms after the use of only manual protective blades without automatic mechanical retraction: 5.1% dysphagia and 0% dysphonia in the immediate post-operative period, P = 0.001.

Conclusions:

Soft tissue damage due to the use of automatic retractors in MACDF is not minor and leads to general discomfort in the patient in spite of good neurological results. These problems most often occur when automatic retractors are used continuously for more than 1 hour, as well as when they are used in multiple levels. Dysphagia, dysphonia and local pain decreased with the use of transient manual blades for retraction, and with intermittent release following minimally invasive principles.

[Mass-gathering medical strategies: The experience in the International Book Fair in Guadalajara]

INTRODUCTION

The Guadalajara International Book Fair (FIL) is a mass gathering, hosting publishing companies from 40 countries and more than 750,000 visitors. It is necessary to prioritize preventive measures focusing on earthquakes, fires, terrorist acts, and prevention of infections. The objective of this study is to describe and analyze the health problems encountered during FIL 2013 in order to improve civil protection services during future events.

MATERIAL AND METHODS

Descriptive, cross-sectional study, collecting medical histories in accordance with Mexican Official Standard NOM-004-SSA3-2012, and classifying respondents into age groups. A total of 794 medical sheets for patients who received assistance at the Mobile Health Units were analyzed.

RESULTS

Altogether, 794 (0.1%) patients were medically evaluated out of 750,987 fair visitors during the study period. Of these, 32 patients were <12 years old; 111 were 13-20 years old; 540 were 20-50 years old; and 111 were >50 years old. There were no complicated medical cases. A favorable impact of preventives strategies was observed.

CONCLUSIONS

Non-complicated medical incidents were observed. It is necessary to increase the knowledge on health among the general public who attend this type of event. Training health professionals is a priority in prevention measures and providing care during mass events of this kind in Mexico's territory.

Early-life exposure to noise reduces mPFC astrocyte numbers and T-maze alternation/discrimination task performance in adult male rats

In this experiment, we evaluated the long-term effects of noise by assessing both astrocyte changes in medial prefrontal cortex (mPFC) and mPFC-related alternation/discrimination tasks. Twenty-one-day-old male rats were exposed during a period of 15 days to a standardized rats' audiogram-fitted adaptation of a human noisy environment. We measured serum corticosterone (CORT) levels at the end of the exposure and periodically registered body weight gain. In order to evaluate the long-term effects of this exposure, we assessed the rats' performance on the T-maze apparatus 3 months later. Astrocyte numbers and proliferative changes in mPFC were also evaluated at this stage. We found that environmental noise (EN) exposure significantly increased serum CORT levels and negatively affected the body weight gain curve. Accordingly, enduring effects of noise were demonstrated on mPFC. The ability to solve alternation/discrimination tasks was reduced, as well as the number of astroglial cells. We also found reduced cytogenesis among the mPFC areas evaluated. Our results support the idea that early exposure to environmental stressors may have long-lasting consequences affecting complex cognitive processes. These results also suggest that glial changes may become an important element behind the cognitive and morphological alterations accompanying the PFC changes seen in some stress-related pathologies.

[Temporal lobe epilepsy and active neurocysticercosis: two representative case reports]

INTRODUCTION

There are limited evidences reported of temporal lobe epilepsy associated with active cysticercosis in cystic stage. The objective is to present the correlation between active cysticercosis in topographical zones associated with temporal lobe epilepsy, with neuropsychiatric manifestations and pattern of secondarily generalized partial seizures.

CASE REPORTS

Two cases of adult patients with neuropsychiatric manifestations of one year evolution, refractory to antipsychotic drug treatment, and who subsequently appear late onset partial-secondarily generalized seizures. Cysticercosis active presence in the temporal lobe in one patient, and the insula in the other, is identified. A better clinical control after albendazol treatment and subsequently anticonvulsant therapy only remained to evaluate pertinence of pharmacological withdrawal criteria.

CONCLUSIONS

Active neurocysticercosis, may be the cause of acquired neuropsychiatric disorders and temporal lobe epilepsy of late onset when the topography is in the mesolimbic circuit. Early etiologic diagnosis and appropriate treatment allows adequate control of their symptoms and potentially final cure.

Ethical implications in the use of embryonic and adult neural stem cells

The advent and growth of technological advances have led to new routes of knowledge. Thereby, we currently face new challenges. We have just started to get a glimpse of the structural and functional role of neural stem cells in differentiation and migration processes, the origin of synaptic networks, and subsequent readjustments in specific circuits. A whole range of treatment possibilities originates from this knowledge that potentially can be used for different neurological diseases in humans. Although this is an encouraging scenario, it implies that the human brain is the object of such study, as well as its potential manipulation and transplantation. It is, therefore, pertinent that ethical principles should be followed in such research to have proper balance between what can be done and what should be done, according to every specific context. Hence, it is wise to consider ethical implications in every research project, along with potential clinical applications, under the principle of causing no harm, following risk and benefit rules in decision making and with respect of the human condition as a priority.

Combined approach for experimental Oto-neurosurgical procedures

Background:

Experimental procedures will continue to be a key element while going through the learning curve in the use of the endoscope and minimally invasive procedures. We describe the technical procedure of an experimental approach to middle ear in New Zealand rabbits through external auditory canal and its relevance as an ideal model to study graft materials and serve as a training tool for potential applications in otoneurology.

Methods:

A group of 28 adult New Zealand rabbits were subjected to an experimental myringoplasty, combining the transmeatal and retroauricular approach with endoscopic assistance and microsurgical technique. The different anatomical steps and systematization of the complete experimental procedure are described.

Results:

An experimental approach to middle ear live model and basic anatomic description was successfully used, standardizing the ideal technique. The eardrum could regenerate with no complications and with functional preservation in all the myringoplasty cases. This strategy involves a safe combined approach to the tympanic membrane and others neurosurgical as transcochlear and translaberyntic approaches and is useful as a test of other experimental procedures to evaluate biomaterials to repair the eardrum currently studied. This experimental myringoplasty model also facilitates functional tests such as impedanciometry and the endoscopic follow-up of the whole process.

Conclusions:

The method described to perform an experimental myringoplasty (type I tympanoplasty) in a New Zealand rabbit is an option to be used as a basic model to study the behavior of the graft in the tympanic membrane. Also, basic concepts for the use of combined instrumentation are established in the treatment of eardrum lesions, as a refinement of the technical training application in microsurgery and assisted endoscopy in the transcochlear and translaberintic approaches and otoneurology areas.

The medical education and its impact on public health. Perspectives and challenges

BACKGROUND

This paper presents an analysis of the relevance of the formation of human resources trained in health sciences as an essential strategy for sustainability projects applied to health schemes. A solid linkage is required between training and application aspects through the transfer of knowledge in concrete actions.

DISCUSSION

A series of actions aimed to improve the quality and coverage in health services has been proposed. However, the treatment given to education and training in human resources has not been in the same proportion. As a consequence, the formation of qualified human resources represents one of the fundamental axes to perform these actions in health fields.

CONCLUSIONS

Training of human resources for health provided by educational institutions must not be separate from global decisions in health fields. Evidence shows that the higher density, quality and appropriate distribution of health workforce, the greater the impact on public health in an efficient manner. This rubric must be considered as a priority, achieving the training of professionals with leadership and with the ability of transforming their environment before the predictions about potential collapses in health systems are presented as an emerging challenge.

Incidental consequences of antihelmintic treatment in the central nervous system

BACKGROUND

Neurocysticercosis (NCC) is the most common parasitic infection in the central nervous system and the most common cause of acquired neurological symptoms in young adults living in developing countries. Many "asymptomatic" patients begin experiencing neurological symptoms after the use of antiparasitic drugs for gastrointestinal treatment. Patients who are previously diagnosed with NCC require special care during cysticidal treatment because of the inflammatory effects caused by the interaction between the drug, the parasite, and the host.

CASE DESCRIPTION

Of a series of 46 cases, we selected five patients with a history of being "asymptomatic" and who began experiencing neurologic symptoms after the use of albendazole, which led to a diagnosis of cysticercosis. Another case of the patient, who already had been diagnosed of ventricular cysticercosis, was given a drug treatment without consulting the neurosurgeon and had a fatal outcome attributable to secondary meningoencephalitis.

RESULTS

In the first five cases, with new neurological symptoms after antihelmintic treatment, the self-prescription is remarkable. The symptoms appear between the third and fifth day of treatment. All of them had a clinical course without complications. Only two cases minimally invasive techniques were required. The case who had been already diagnosed developed meningoencephalitis and died after eight days of antihelmintic treatment.

CONCLUSIONS

Anthelminthic drug treatment requires tailor-based prescription considering risk-benefit ratio with the drug-parasite-host interaction in mind. Treatment is not harmless so patients have to be closely watched. In select cases, medical treatment cannot replace surgical procedures, which can be the primary approach with drug treatment as a complement.

A new bilayer chitosan scaffolding as a dural substitute: experimental evaluation

OBJECTIVE

To evaluate whether bilayer chitosan scaffolding (BChS) can provide a watertight dural closure and permit regeneration by fibroblasts in an experimental in vivo model.

METHODS

In the in vitro phase, BChS was elaborated and the following characteristics were evaluated: pore size, thickness, water absorption capacity, tensile strength, strain, and toughness. In the second in vivo phase, 27 durectomized New Zealand rabbits were randomly assigned into three duraplasty groups with autologous dura, collagen matrix (CM), or BChS. In all groups, fluid leakage pressure was measured at 10, 21, or 180 days. Histology response to regeneration was evaluated through hematoxylin and eosin stain.

RESULTS

BChS was standardized to obtain bilayer scaffoldings with a nonporous layer and a porous layer. The pore size was 10 μm, total thickness was 400 μm, strain was 57.8%, and tensile strength was 5.5 gr/mm(2). The physical characteristics of BChS allowed dural closure without cerebrospinal fluid (CSF) leak. There were no differences in fluid leakage pressures between the BChS, dura, and CM groups. Histologic analysis showed fibroblast migration with adequate dural regeneration.

CONCLUSIONS

BChS is an ideal alternative for a watertight dural closure because it can be sutured, and it induces organized regeneration with fibroblasts without evidence of fibrosis.

Long-term follow-up and pregnancy in a patient with neurenteric cyst: case report

BACKGROUND

Neurenteric cysts (NC) are rare congenital anomalies. Cysts are secretory with an epithelial lining and features that resemble those of gastrointestinal and/or respiratory mucosa. They originate embryologically and result from an incomplete separation of the neurenteric canal from the foregut.

CLINICAL CASE

We describe the 21-year follow-up of a female patient with a history of partial control of urinary and anal sphincters. The patient had a 6-month course of pain associated with saddle hypoesthesia, limited gait, chronic constipation, plus inferior paresthesia of the limbs. These features, along with the MRI findings, were compatible with the diagnosis of neurenteric cyst. The patient underwent two surgical procedures. We used a nonradical approach because of the connection of the cyst with the rectum and nerves in the deep plane. At age 22, she became pregnant and, after an uneventful gestation, gave birth to a healthy newborn.

DISCUSSION

The selection of surgical strategy is oriented to mass effect resolution. In accordance with the literature, evaluation of the best choice for each patient is mandatory to obtain a balance of the risk and the potential functional preservation. This report demonstrates the importance of sensory and motor function preservation instead of using aggressive treatment.

CONCLUSION

Our goal in each procedure was symptom alleviation, reduction of cyst size, clearance of the mass effect, and an attempt to resect the cyst capsule as much as possible without compromising quality of life and neurological functions.

[Bioethical triangle of transplants]

BACKGROUND

Organ transplantation is one of the highest forms of medical procedures due to the many technical implications as well as to new frontiers to be conquered while searching for new therapeutic options that reach far beyond ordinary decisions. Although technical skills were developed primarily, it was not until immune reaction to rejection was understood and control of biological variables achieved that transplantation acquired a greater scope. Bioethical performance is currently a challenge. As a human multidisciplinary activity, this is not without bias or skew. Therefore, the social and cultural context in the deontological and bioethical sense acquire the greatest relevance, particularly when values and principles inherent to human life are taken into account along with the complex angles derived from human interactions in the bioethical triangle.

CONCLUSIONS

This triangle is represented by the individual requiring an organ, the person who is the donor under specific circumstances, and the individuals who are responsible for procurement, transplantation and evaluation of the validity of this therapeutic option.

Locomotor activity is a predictive test after global ischemia-reperfusion in Mongolian gerbils

OBJECTIVE

The Mongolian gerbil is one of the main animal species used for the study of global ischemia, due to its specific Circle of Willis. Because of their anatomic variations, a large number of animals is needed. On account of the specific vulnerability of the hippocampus, striatum and neocortex, it is possible to evaluate the severity of the ischemic damage through an analysis of locomotor activity. The tests support the sensitvity of the experimental sample and compensate the interanimal variability.

METHODS

The locomotor pattern of 30 male Mongolian gerbils was recorded before they were subjected to experimental bilateral carotid clippage for 15 minutes followed by reperfusion. A transparent 75x50x90 cm acrylic box was filmed in order to determine the total distance covered by the animals in five minutes, for three consecutive days. The locomotor activity of the animals was also examined in an open field at 24 hours and seven days after ischemia. Serum neurospecific enolase (NSE) was measured in the ischemic group and compared with that of an intact control group.

RESULTS

The recording for normal animals was uniformly similar (average 200 squares in periphery), in the first trial of 3 consecutive days (188+/-6.7 S.D.). After ischemia, the numbers increased to 388 (+/- 40 S.D.), indicating that they were sensitive to the ischemic episode. Seven days later they returned to basal values. Serum NSE was high in the ischemic group versus the intact control group (S=<0.001).

CONCLUSIONS

Locomotor activity in an open field is a useful reference as a predictive test to determine the sensitivity of experimental animals to ischemia. It is also associated to the degree of cerebral damage in global ischemia-reperfusion, and this behavior is representative of the expression of selective ischemic injury. The determination of NSE is useful as an associated parameter of ischemic injury.

Trans-supraorbital approach to supratentorial aneurysms

OBJECTIVE

The trans-supraorbital approach has the advantage of combining the keyhole principle with cranial base surgery. The anatomic fields that can be visualized with the use of this procedure have been demonstrated in cadavers, and the advantages and potential surgical applications of this procedure are described in this report. This article is the first to describe a group of intracranial supratentorial aneurysms.

METHODS

We used the trans-supraorbital approach in 22 cases of supratentorial aneurysms. In this technique, an incision is made through the eyebrow, then a 3.5-cm craniotomy is performed with en bloc extension to the orbital arch, complemented by different drilling extensions of the orbital roof according to the surgical objective. We describe the anatomic details of the experimental work as well as the clinical results.

RESULTS

The trans-supraorbital technique offers an unlimited wide exposure of neurovascular structures in this microsurgical corridor. The craniotomy extension allows greater exposure than the conventional keyhole supraorbital approach, which makes the technique safe for the patient and comfortable for the surgeon. All patient outcomes were successful; no serious complications from the surgical technique occurred. Our success was achieved through better microscopic illumination in the deep field and by gaining access to the complete supratentorial vascular territory with minimal cerebral retraction and an acceptable cosmetic result.

CONCLUSION

The trans-supraorbital approach is effective for gaining access to and treating supratentorial aneurysms. Also, the microsurgical field is more convenient in microscope-assisted surgery because total reliance on the endoscope is not required, and minimal brain retraction is needed. This modification of the keyhole procedure also provides multiple surgical options in this microsurgical corridor, using the principles of minimal invasiveness in cranial base surgery.

Acute interhemispheric subdural hematoma: two case reports and analysis of the literature

Interhemispheric subdural hematoma (ISH) had been considered extremely rare until identification with imaging studies. Its natural history is still quite unknown in terms of potential origin and course. As a consequence of various controversies, there is still no clearly established treatment, particularly in regard to medical or surgical management. The best decision requires tailoring treatment to the individual patient according to his or her clinical condition. Two patients with acute interhemispheric subdural hematomas are reported, the controversial management of this rare entity is analysed. In reviewing current published cases of interhemispheric subdural hematoma, it seems that the outcome of an individual patient is not related to the therapeutic approach, but to the level of consciousness and the neurological condition on admission. Surgical and medical treatment indications are taken into account for management. A patient with ISH developed an extension of the hematoma to the convexity at 2 weeks of his clinical course, with a decline of his neurological condition. The hematoma was then evacuated through a parietal craniotomy with an uneventful postoperative course. Another case of ISH presented as headache and TIA, with spontaneous clinical improvement at 12 hours and with no decline in the patient's neurological condition. Management was conservative. In both cases the neurological examination was normal after 6 months. As in previously reported cases, the clinical and neurological condition of the patient on admission is crucial for the course of an ISH. Treatment strategies are based on the individual neurological response of each case and the risk-benefit ratio to decide on a medical or surgical approach.

[Cerebral death and bioethics]

INTRODUCTION

Brain death has been a topic of great interest for clinicians throughout the history of Neurosciences. There are so many different ideas about this topic that it has been necessary to constantly define further the criteria and medical decisions applicable in this field. Also about this matter there are a set of cultural, philosophical and religious aspects as well as autonomous principles in the people involved in such an event. Questions and dilemmas are still present in the individuality of every case and especially in terms of management of information and circumstances that define brain death.

DEVELOPMENT

This essay tries to analyze the medical and historical issues around death and its relation to the context of brain death as such. There are also a series of reflections supported by the current bioethical thoughts that are identified with a cultural framework that is crucial to acknowledge the way in which the doctor, the family and society approach an event such as brain death. In spite of all the development of diagnostic technology and the extremes of the futility and extreme cruelty of treatments; there are still open questions that require to be looked into with objective criteria and scientific rigor.

CONCLUSION

We should not put aside bioethical principles that are inherent to human quality and dignity that touch the sensitivity of those who give out the information and those who receive it within this process of interaction between the medical staff and the family.

The trans-supraorbital approach

The trans-supraorbital approach represents the advantage of combining the keyhole principle and skull base surgery. In cadaveric work the author shows the anatomic fields visualized with this procedure, advantages and potential surgical applications. The experimental surgical procedure was performed on 8 adult skulls and on 3 cadavers with intact cerebral structures. First, a 2 cm supraorbital approach for endoscopic exploration was used. The basic anatomic landmarks and corresponding dimensions of the microsurgical field were recorded and then compared with those from the trans-supraorbital approach, after removing the orbital arch and other parts of the orbital ceiling. This technique offers a 0.5 cm average increase in surgical field from the craniotomy. The surgical distance that results is shorter (about 2 cm), as well as the length of the surgical instruments required. A better microscope illumination in the deep fields, and the possibility of access to the intraorbital region, the superior orbital fissure, the optic foramen, and the cavernous sinus through the clinoid space are also obtained, with minimal cerebral retraction and similar advantages as through the pterional trans-sylvian approach. The author concludes that by extending the craniotomy and decreasing the surgical distance, the microsurgical field is more convenient for microscope-assisted surgery without totally relying on the endoscope, and with minimal brain retraction. It also provides multiple options to approach vascular and tumor lesions found in these microsurgical corridors, combining principles of minimal invasion and skull-base surgery.

Neuroprotection in selective focal ischemia in rats by nitrates, an alternative redox manipulation on nitric oxide: experimental model

The recent advances in the histopathology of ischemia have set forth new proposals, particularly in regard to excitotoxicity by the glutamate receptor, NMDA. The participation of the nitric oxide (NO) in normal and pathological conditions and its relationship with toxicity in ischemia, suggest new alternatives for the modulation of the NMDA receptor REDOX site through its pharmacologic manipulation. This event would potentially limit the consequences of the activation-calcium flow and the production of peroxoinitrite during the ischemic phenomenon. The present work delivers two proposals: 1) A modified technique to the ones that have been described, of endovascular, without craniectomy, for experimental cerebral ischemia in Wistar rats, and with particular harmful effect upon the hippocampus. 2) It promotes the use of nitrates as an additional alternative to other elements, in order to restrict excitotoxicity in the described experimental cerebral ischemia, and paying attention to CA1-CA2 of the hippocampus. This area, specially sensitive to hypoxia-ischemia, offers an excellent study option for focal, experimental, cerebral ischemia associated with toxicity mediated by excitatory amino acids, since it stores an important concentration of NMDA receptors (R1/R2 A) as well as endothelial nitric oxide synthase. Our parameters are supported by quantitative-qualitative cell analysis, and not by the extension of the stroke which offers a more objective perspective upon the assessment of the focal ischemic event. By means of this technique, these results confirm the extent of the ischemic injury to the cell at the level of the hippocampus compared to a control/basal group, P = 0.0006. Furthermore, it suggests a neuroprotective effect of isosorbide dinitrate since it preserves the viable cells, and limits the appearance of hypoxic-ischemic cells at the hippocampus when the middle cerebral artery (MCA) is occluded endovascularly, as compared to the animals with no treatment P = 0.0080. However, other research lines are needed to compare the efficacy of this present work with other therapeutic proposals.