Internal capsule: Seth of dissectors for an integral boarding of its fibers

Abstract

Introduction: Classically, the morphologic study of the internal capsule (IC) is made by two cuts: the coronal of Charcot and the axial of Fleschig. Recent neuroradiologic studies and clinical investigations contribute to the observation in the non-invasive form of this region.

Objective: The present work tries to complement the study of this important anatomical region, demonstrating it in integral and three-dimensional form. For that reason, the channeled soundings and instruments of manicurist and odontology were modified, and were conformed to a Seth of dissectors designed specifically to approach the IC. Each dissector presents particular characteristics, which allows the delicate dissections of the different anatomical structures to be made.

Materials and methods: Twenty encephala of adult corpses were used for this investigation, fixed with a solution of formol to 10% in distilled water. They were approached at the external face of the cerebral hemisphere at level of the lateral fissure. The middle cerebral artery and the insula lobe were dissected and extirpated using the dissector no. 1, exposing the extreme capsule. The dissector no. 2 was used to dissect the fibers and the extreme capsule was extracted jointly with the claustrum, demonstrating the external capsule. The fibers were dissected using the dissector no. 3, thus exposing the lentiform nucleus. Then, the external face of the nucleus was delimited with the dissector no. 4 and then underwent exeresis, to allow for the entry of the genu of the IC. The genu constituted nervous fibers, laid out vertically and perpendicular to the greater axis the nucleus before mentioned. The fibers were dissected with the dissector no. 5, also appreciating the route of the lenticuloestriadas arteries that irrigate the region in the study. Using the dissector no. 6, nervous fibers of the corona radiata were dissected, as well as the short arciformes fibers and the endings in the cerebral cortex. Lastly, the dissector no. 7 was used to dissect the fibers of the pyramidal route and their route by the cerebral trunk, from above to below.

Conclusion: With the use of the presented instruments, a selective boarding of the IC was obtained, and thanks to the specific characteristics of each dissector, the different anatomical structures related to the IC can be approached with facility. Also, the nervous fibers that compose it can be dissected, which expose the IC in an integral and three-dimensional way.     

Loss of heterozygosity on chromosomes 10q, 9p, 17p and 13q in Malays with malignant glioma

Abstract

Recent advances in neuro-oncology have revealed different pathways of molecular oncogenesis in malignant gliomas including loss of heterozygosity on chromosomal regions harboring tumor suppressor genes. In the present study, we performed polymerase chain reaction–loss of heterozygosity (PCR-LOH) analysis using microsatellite markers to identify loss of heterozygosity on chromosomes 10q, 9p, 17p and 13q in the Malays with malignant gliomas. Of 12 cases with allelic losses, seven (58.3%) cases showed LOH on chromosome 10q, three (25.0%) cases showed LOH on chromosome 9p, four (33.3%) cases showed LOH on chromosome 17p and two (16.7%) cases showed LOH on chromosome 13q. The cases include five (41.7%) cases of glioblastoma multiforme, three (25.0%) cases of anaplastic astrocytoma, three (25.0%) cases of anaplastic oligodendroglioma and one (8.3%) case of anaplastic ependymoma. Four cases showed loss of heterozygosity on more than one locus. Our findings showed that loss of heterozygosity on specific chromosomal regions contributes to the molecular pathway of glioma progression in Malay population. In addition, these data provide useful evidence of molecular genetic alterations of malignant glioma in South East Asian patients, particularly in the East Coast of Malaysia.     

Optimal dosing as a necessary condition for the efficacy of hyperbaric oxygen therapy in acute ischemic stroke: A critical review

Abstract

The effectiveness of hyperbaric oxygen therapy (HBOT) in clinical and experimental acute ischemic stroke (AIS) has been controversial for many years. However, in the literature, no data was found on the dose/effect of HBOT in patients with AIS. We analyzed retrospectively the published data of clinical studies performed in different hyperbaric centers (a total of 265 patients). The dose of HBOT (D_HBOT) was calculated considering the product intrabarochamber pO₂ (ATA), the duration of a single HBOT exposure (hours), and the number of HBOT treatments. Efficacy of HBOT (Ef_HBOT) data regarding the number of patients who showed significant clinical improvement of their neurologic status in the course of the treatment HBOT (the percentage of the total number of patients). The level of Ef_HBOT in each study was compared with a corresponding value of D _HBOT. A comparison of the data shows a pronounced tendency H for higher values of Ef_HBOT as the level of the average values of the total D_HBOT increases. The coefficient of correlation between these parameters appears to be fairly high (r = 0.92). The maximum possible value of Ef_HBOT is 100%, which corresponded to the average values of D_HBOT at a level of no less than 30 agreed units. The examined data suggest that applying optimal total D_HBOT may provide a maximum possible Ef_HBOT in treating patients with AIS.     

Quality of Life of Victims Bullies,and Bully/Victims Among School-Aged Children in the Netherlands

Two studies were conducted to examine the Quality of Life (QoL) of victims, bullies and bully/victims among Dutch school-aged children. Study 1 studied associations of QoL dimensions with self-reported victimisation in the Dutch sample from the KIDSCREEN Project (N = 1,669). Study 2 examined QoL of self-reported and peer-nominated victims, bullies and bully/victims using baseline data from an evaluation study of an anti-bullying intervention (N = 3,483). In both studies victimisation appeared to be consistently associated with statistically significantly poorer child and adolescent QoL in regard to all QoL dimensions measured. The strongest associations were found with the QoL dimension Moods and Emotions and least with QoL regarding Physical Well-Being. This indicates that victims of bullying are generally less happy and cheerful, feel sad and depressed more often, have a less positive perception of themselves and are less positive about going to school than non-involved children. Active bullying was only associated with decreased QoL in regard to School Environment. That is, bullies are on average less positive about going to school and attending classes than non-involved children are. Finally, QoL of bully/victims mostly resembled that of victims; whereas the association of being a bully/victim was strongest with the QoL dimension Moods and Emotions, the association with QoL regarding Physical Well-Being appeared to be statistically non-significant.     

Motor recovery after stroke: Lessons from functional brain imaging

Abstract

Several theories have been proposed to explain recovery from stroke. Functional brain imaging offers an opportunity to evaluate these theories and visualize recovery after stroke. Functional brain imaging has proven to be an effective tool to map brain areas activated during a specific task. This paradigm can extend our understanding of the mechanisms of motor recovery after stroke. Functional brain imaging tools such as functional MRI, PET, transcranial Doppler ultrasonography, and transcranial magnetic stimulation can be used to evaluate motor activation after stroke. Functional imaging is proving useful in identifying areas, pathways and mechanisms involved in motor recovery after stroke. Studies have shown changes in motor organization with rehabilitation. Functional brain imaging may assist in the selection of rehabilitation methods that best foster recovery. [Neurol Res 2002; 24: 453-458]     

Inhibition of AF116909 gene expression enhances the differentiation of neural stem cells

Abstract

Objectives: Neural stem cells (NSCs) are self-renewed, pluripotent cells that can differentiate into neurons, astrocytes and oligodendrocytes. Such multipotency that allows production of specific types of nerve cells for basic research and therapeutic purposes depends on how these cells are directed in their differentiation. Here, we investigate the function of the AF116909 gene in the differentiation of NSC.

Methods: NSC culture was isolated from the striatum corpora of embryonic brain tissues in a 14-day pregnant rat. A constructed RNAi (RNA-mediated interference) vector was transfected to knock down the expression of this gene. Afterwards, RT–PCT was applied to examine the presence of endogenous AF116909 mRNA and the effect of RNA interference.

Results: After the knockdown of this gene, we detected that the differentiation rate of cells was enhanced to 80% on the 11th day in comparison with 12% in the control cells transfected with the expression vector alone.

Discussion: These findings suggest that AF116909 functions in inhibiting the differentiation of NSCs, and AF116909 gene-targeting by RNAi provides a useful method to study the differentiation mechanisms of NSCs.     

Randomized evaluation of adverse events and length-of-stay with routine emergency department use of phenytoin or fosphenytoin

Abstract

Intravenous phenytoin has come under increased scrutiny with the introduction of the prodrug, fosphenytoin. We evaluated adverse events and length-of-stay using parenteral the two drugs in routine emergency department use. Open-label randomization of phenytoin or fosphenytoin in 256 Emergency Department patients prescribed 279 parenteral doses of a phenytoin-equivalent. All phenytoin was administered intravenously, and fosphenytoin was given intravenously or intramuscularly (physician preference). Adverse events and Emergency Department length-of-stay were recorded; re-presentation to the Emergency Department within three months was reviewed for evidence of the purple glove syndrome. Nonparametric statistics were used to analyze the data. Seventy-seven patients received phenytoin and 202 fosphenytoin; 28 (10.0%) received intramuscular fosphenytoin. The mean phenytoin-equivalent dose was similar between the groups. Eighteen patients required reduction in infusion rates because of an adverse event (phenytoin = 6.5%, fosphenytoin = 6.4%; OR 0.9, 95% CI 0.42.6; p = 1.0). Adverse events occurred with similar frequency (phenytoin 9.1%, fosphenytoin 15.8%; OR 0.7, 95% CI 0.31.4; p = 0.3). The most common events were: pruritis, pain on infusion, and paresthesias. One patient developed hypotension (fosphenytoin); there were no other serious adverse events, including phlebitis. Median Emergency Department length-of-stay was 6.7 h for phenytoin and 5.7 h for fosphenytoin (p = 0.6). In routine Emergency Department use, our data do not support formulary conversion from phenytoin to fosphenytoin, based on the incidence of adverse events or Emergency Department length-of-stay.     

Distribution of artificial cerebral microemboli in stroke patients with patent foramen ovale

Abstract

Objectives: Patent foramen ovale (PFO) is considered as an important risk factor for cerebrovascular diseases. Nevertheless, the relationship between the distribution of highintensity transient signals (HITS), resulting from injection of air mixed with saline and detected by transcranial Doppler (TCD), and clinical cerebrovascular syndromes in these patients has not been investigated.

Methods: Using TCD, we screened 40 patients with stroke or transient ischemic attack (TIA), in whom PFO was proven by transesophageal echocariography (TEE). Of these, 30 patients (75%) with artificially produced HITS either in the middle cerebral artery (MCA) or the basilar artery (BA) were included in the analysis.

Results: Nineteen patients had a stroke or TIA in the carotid territory and 11 patients in the vertebro-basilar territory. HITS were found in the MCA in all 30 patients and in 21 of the 30 patients in the BA. Of the latter, ten patients were in the carotid group and 11 patients were in the veretebro-basilar group, p=0.011.

Conclusion: There is a significant association between the distribution of artificial HITS and the clinical cerebrovascular syndromes.     

Social Support and Sense of Coherence: Independent,Shared and Interaction Relationships with Life Stress and Mental Health

Both perceived social support and sense of coherence are used extensively as intervening factors to predict and explain the relationship of external factors to individuals' state of mental health. The aim of the study was to investigate whether the present operational definitions of these concepts measure the same or different dimensions of the intervening process and/or have a distinct interaction effect on mental health. A survey was carried out in seven local communities in Lofoten, a series of islands in Northern Norway. The questionnaires were constructed for self-completion and delivered to all households (people 18 years and above) in the selected communities. Sixty-seven per cent of the universe responded (N = 1062). By factor analysis, the items were subdivided for perceived social support and sense of coherence. The two concepts make both significant independent and shared contributions to explained variance on the mental health index. All second-order terms (any combination of two of the indexes, sense of coherence, perceived social support or negative life events) show modification effects with regard to mental health. The combination of sense of coherence, perceived social support and negative life events showed a thirdorder effect modification with regard to mental health. The interaction between social support and sense of coherence increases with the number of experienced negative life events. Thus all three factors need to be considered to maximise the efficiency of health promotion projects.     

Neuropathy is a major contributing factor to diabetic erectile dysfunction

Abstract

Erectile dysfunction (ED) in diabetes is multifactorial. So far, the impact of neuropathy has not been well determined. This study was performed to assess the frequency of abnormal neurophysiological tests in patients with ED due to diabetes compared to patients with ED due to nondiabetic neuropathies in order to estimate the contribution of neuropathy in diabetic ED. Forty-nine men with ED were studied. We classified ED as 'diabetic', 'neuropathic' or 'ED of other origin'. 26.6% of the men fulfilled the criteria of diabetic ED, 42.9% had neuropathic ED. In every patient history taking, a questionnaire focusing on autonomic symptoms other than ED, clinical examination, nerve conduction studies (NCS), sphincter ani electromyography (EMG), heart rate variability testing (HRV) and quantitative sensory testing (QST) was performed. Vascular function was assessed by the intracavernosal prostaglandin E1 (PGE1) injection test. The frequency of abnormal results in diabetic and neuropathic patients was compared. Vascular function was abnormal in only one patient with diabetic ED and three patients with neuropathic ED. Both groups had similar frequencies of autonomic symptoms other than ED (64% in diabetic vs. 64% in neuropathic patients), abnormal EMG (33% vs. 40%) and abnormal QST (vibratory perception 83% vs. 84%, cold perception 9% vs. 19%, warm perception 42% vs. 43%). Abnormal clinical findings (50% vs. 33%), NCS (75% vs. 50%) and HRV (39% vs. 25%) were slightly, but not significantly more frequent in men with diabetic ED than neuropathic ED. The tests indicating neuropathy showed abnormalities in men with diabetic ED as frequently as in men with neuropathic ED. Some tests even suggested neuropathy more often in diabetic than in neuropathic ED. The findings support the hypothesis that neuropathy contributes significantly to the pathophysiology of ED in diabetes mellitus. [Neurol Res 2001; 23: 651-654]     

Spatiotemporal Model of Family Engagement: A Qualitative Study of Family-Driven Perspectives on Family Engagement

The Family-School-Community Partnerships Practice Group of the National Community of Practice on Collaborative School Behavioral Health conducted a survey of 30 families across the United States in an effort to develop a family-driven definition of family engagement. Literature on family engagement is reviewed, qualitative methods using a grounded theory approach are described and a model of family engagement is presented. The resulting spatiotemporal model of family engagement puts forth family engagement as a process that represents a continuum, either moving toward increased partnership between families with children with mental health needs or sliding away from that goal, as part of a larger developmental process. We hope that this model may enable us to begin to recognize early when we fall into patterns that take us away from increased collaboration between systems and families, and to support identification of the next steps toward righting those relationships.     

The Effects of a School-Based Educational Intervention on Preadolescents' Knowledge of and Attitudes towards Mental Illness

This study set out to identify the sources of help Irish adolescents would be willing to access when distressed, and to investigate associations between participants' willingness to seek help and their emotional and behavioural difficulties. The participants were 1079 thirteenfifteen year old secondary school students. They completed the Strengths and Difficulties Questionnaire (Goodman, 1997) and a specially designed measure assessing likelihood of seeking help from various sources, as part of the baseline assessment in an on-going evaluation of a school-based mental health promotion initiative. Results show that participants are most willing to seek help from informal sources when distressed, and males are significantly more likely than females to report that they would not seek help from any source. Greater reluctance to seek help is associated with increased difficulties for both males and females. Possible barriers to help seeking by adolescents are discussed.     

Mental Health Promotion in Irish Schools: A Selective Review

School-based mental health promotion work continues to attract considerable attention in the general health promotion literature. Schools certainly represent one important element in any integrated system of health promotion, with both guaranteed availability of large target groups of pupils and the expertise of experienced teachers. Given high rates of identified youth psychopathology and the recognised inadequacy of youth mental health services, Irish schools are increasingly seen as important locations for preventative mental health promotion work. Some general issues in effective health promotion are outlined. The review then describes the application of a representative selection of mental health promotion resources in Irish schools, and identifies some emerging common elements. Optimising the delivery and selection of resources is then discussed, and one resource is examined. The review concludes with discussion of likely future developments in Irish school-based mental health promotion.     

Contextual Features of Public Schools in the United States as Settings for Mental Health Promotion

Scanning the current policy and practice landscape of mental health promotion in the United States reveals indicators of significant progress in establishment of comprehensive school-based programs and services. At the same time, however, there remain significant challenges to advancing the SMH agenda. Using a conceptual lens, the authors elucidate fundamental political and practical dimensions of public education that must be addressed, including collaboration with stakeholders opposed to school mental health and partnering with teachers in mental health promotion. Concept mapping is introduced as a strategy to increase understanding about the role of school mental health in public education.     

Purinergic mechanisms of the nucleus of the solitary tract and neural cardiovascular control

Abstract

Objectives: This review addresses the role of central purinergic receptors in the operation of the cardiovascular reflexes.

Methods: Potential physiological role of purinergic receptors operating in the nucleus of the solitary tract (NTS) was assessed via comparison of the regional patterns of hemodynamic and sympathetic responses evoked by selective stimulation/inhibition of NTS purinergic receptor subtypes, with the patterns evoked by stimulation and unloading of arterial baroreceptors, and other known patterns of autonomic responses. The effects of sino-aortic denervation plus vagotomy and ionotropic glutamatergic blockade of NTS mechanisms on the patterns of the responses were also considered.

Results: Selective stimulation of NTS A1 receptors with CPA evoked a pattern of regional autonomic responses consistent with inhibition of baroreflex mechanisms and facilitation/ disinhibition of chemoreflex mechanisms. Selective stimulation of NTS A_2a receptors with CGS 21680-evoked pattern of the responses different than that evoked by stimulation of baroreflex afferents what remains in contrast to previous reports suggesting that NTS A2a receptors facilitate baroreflex transmission. The pattern of the responses was similar to that observed during hypotensive hemorrhage. Preferential, b -adrenergic iliac vasodilation evoked by stimulation of adenosine A2a receptors and preferential activation of sympathetic output to the adrenal medulla by both adenosine A1 and A2a receptors are consistent with contribution of these receptors to the defense response, stress and exercise. These observations support previous findings that NTS A1 receptors contribute to the hypothalamic defense response. The effects of stimulation and blockade of NTS P2x receptors with α, β-methylene ATP and suramin, respectively, suggested that neuronally-released ATP operating via P2x receptors may be a crucial co-transmitter with glutamate in mediating baroreflex responses.

Discussion: The above observations strongly suggest that purinergic receptor subtypes operating in NTS circuitry are linked to specific afferent and descending mechanisms primarily integrated in the NTS.