Informed consent in cancer clinical care: Perspectives of healthcare professionals on information disclosure at a tertiary institution in Uganda.

INTRODUCTION: While there have been several studies examining the understanding and quality of informed consent in clinical trials of cancer therapies, there is limited empirical research on health practitioners' experiences on the informed consent process in cancer care, especially from low resource settings. This study explored health professionals' perspectives on information disclosure during the consenting process in cancer care. METHODS: A qualitative descriptive approach was used to collect data. Face to face interviews were conducted with 10 purposively selected healthcare professionals who were actively involved in soliciting informed consent at a cancer treatment centre in Uganda. A thematic approach was used to interpret the results. RESULTS: There were five key themes, and these included information disclosure to patients; assessment of patients' cancer awareness, treatment preferences and expectations; informed consent practices; barriers to optimal informed consent and information disclosure; and recommendations for improving the consenting process. All respondents appreciated the value of disclosing accurate information to patients to facilitate informed decision making. However, the informed consent process was deemed sub-optimal. Respondents asserted that patients should be the psychological wellbeing of patients should be protected by mentally preparing them before disclosing potentially distressing information. All healthcare professionals were appreciative of the central role the family plays in the consenting process. CONCLUSION: Overall, informed consent practices were not ideal because of the several challenges. Inadequate time is devoted to information disclosure and patient education; there is lack of privacy; and informed consent documentation is poor. There is a need for significant improvement in informed consent practices and healthcare professional-patient communication.

Periodontitis is associated with insulin resistance in adults living with diabetes mellitus in Uganda: a cross- sectional study.

INTRODUCTION: Evidence suggests that majority of patients with diabetes mellitus in Uganda have poor glycaemic control as well as periodontal disease. This study set out to determine the association between periodontitis and insulin resistance in adult patients with diabetes mellitus in Uganda using the triglyceride glucose index. METHODS: Two hundred and twenty-three adult study participants with confirmed diabetes mellitus were enrolled in a cross-sectional study. Oral examination was carried with the aid of a periodontal probe to determine the periodontal status and findings recorded using the WHO Oral Health Assessment Tool for Adults, 2013. We recorded clinical details for body mass index (BMI in kg/m2) and laboratory parameters including fasting blood sugar (mmol/L), glycated hemoglobin levels (HbA1c, %) and serum triglycerides (mmol/L) using a study questionnaire. Data were analyzed using R version 4.10. The glucose triglyceride index was used as a measure of insulin resistance. Logistic regression analysis carried out to determine the factors associated insulin resistance. RESULTS: The majority of the study participants was female (70%) with an average age of 48.5 years (SD+/- 11.1). The mean body mass index was 29.6 kg/m2 (SD+/- 5.82). The mean serum triglyceride index was 9.48 (SD+/- 0.675). Eighty-six-point 1% of the participants had periodontal disease. Bivariate analysis revealed high odds for male sex (OR = 1.31, 95% C.I = 0.44-4.84, p = 0.65) and periodontitis (OR = 3.65, 95% C.I = 0.79-26.15, p = 0.13) but low odds for a high BMI (OR = 0.45. 95% C.I = 0.07-1.67, p = 0.30). Multivariate regression revealed a significant association between insulin resistance and periodontitis. (AOR = 3.52, 95% C.I = 1.19-1.83, p = 0.03). CONCLUSION: Insulin resistance is highly prevalent in patients with diabetes mellitus in Uganda and is associated with periodontitis and low body weight.

Informed consent process for emergency surgery: A scoping review of stakeholders' perspectives, challenges, ethical concepts, and policies.

Background: A scoping review of literature about the informed consent process for emergency surgery from the perspectives of the patients, next of kin, emergency staff, and available guiding policies. Objectives: To provide an overview of the informed consent process for emergency surgery; the challenges that arise from the perspectives of the patients, emergency staff, and next of kin; policies that guide informed consent for emergency surgery; and to identify any knowledge gaps that could guide further inquiry in this area. Methods: We searched Google Scholar, PubMed/MEDLINE databases as well as Sheridan Libraries and Welch Medical Library from 1990 to 2021. We included journal articles published in English and excluded non-peer-reviewed journal articles, unpublished manuscripts, and conference abstracts. The themes explored were emergency surgery consent, ethical and theoretical concepts, stakeholders' perceptions, challenges, and policies on emergency surgery. Articles were reviewed by three independent reviewers for relevance. Results: Of the 65 articles retrieved, 18 articles were included. Of the 18 articles reviewed, 5 addressed emergency informed consent, 9 stakeholders' perspectives, 7 the challenges of emergency informed consent, 3 ethical and theoretical concepts of emergency informed consent, and 3 articles addressed policies of emergency surgery informed consent. Conclusion: There is poor satisfaction in the informed consent process in emergency surgery. Impaired capacity to consent and limited time are a challenge. Policies recommend that informed consent should not delay life-saving emergency care and patient's best interests must be upheld.

Genetic and Genomic Researchers' Perspectives on Biological Sample Sharing in Collaborative Research in Uganda: A Qualitative Study.

Numerous ethical, legal, and social issues arise with biological sample sharing. The study explored the perspectives of genetic and genomic researchers on the sharing of biological samples in international collaborative research. Qualitative in-depth interviews were conducted with 15 researchers. Participants expressed positive attitudes towards biobanking and appreciated the benefits of cross-border sharing of biological samples but noted that this practice had adversely affected local capacity building efforts. There was limited understanding of the ethical and regulatory frameworks governing sample sharing. Researchers emphasized the importance of respecting cultural values in biobanking research. Issues concerning poor governance and inequitable benefit sharing were also raised. There is a need for fair and equitable international collaborations where all researchers are treated with respect and as equal partners.

Quality of life of patients with traumatic spinal cord injuries: a cross-sectional study at a tertiary hospital in Uganda.

Background: The study aimed to assess the perceived quality of life of patients with traumatic spinal cord injuries. Methodology: This was a cross sectional study conducted in the Spine Unit of a tertiary hospital in Uganda. The study population comprised of patients with spinal cord injuries. Data were collected using the WHO Quality of Life Brief questionnaire and Functional Independence Measure tool. Results: 103 patients participated in the study, most were male (73.8%), and had a mean age of 37.7 years. Most participants were married (57.3%), unemployed (72.8%) and had no steady source of income (62.1%). Road traffic accidents accounted for most injuries (59.2%). The mean duration since injury was 20.5 months. Most participants (58.3%) had incomplete spinal cord injuries and 84.5% had complications. The perceived overall quality of life was poor in 87.4% of patients. Being employed (p= 0.02), the presence of complications (p= 0.03), and injury severity (p= 0.003) significantly affected quality of life. Functional independent measure scores were significantly better in individuals less severe injuries and those with lumbar level of injury with mean scores of 113.1±8.9 and 99.9±15.3 respectively. Conclusion: The overall self-reported quality of life among patients with traumatic spinal cord injury was generally poor.

Benefit sharing in genomic and biobanking research in Uganda: Perceptions of researchers and research ethics committee members.

Background: Genomic and biobanking research has increased in Africa over the past few years. This has raised pertinent ethical, legal, and societal concerns for stakeholders such as sample or data ownership, commercialization, and benefit sharing. There is limited awareness of the concept of benefit sharing by stakeholders in sub-Saharan Africa. Objective: This study aimed to explore the perceptions of researchers and research ethics committee members on benefit sharing in international collaborative genomic and biobanking research. Methods: Qualitative in-depth interviews were conducted with 15 researchers and 19 research ethics committee members. A thematic approach was used to interpret the results. Results: Six themes emerged from the data and these included perceptions on the benefits of genomic and biobanking research; discussion of benefit sharing with participants during the informed consent process; legal implications of benefit sharing and the role of material transfer agreements; equity and fairness in sharing the benefits of genomic research; perceived barriers to fair benefit sharing; and recommendations for fostering fair and equitable benefit sharing in genomic and biobanking research. Most respondents clearly understood the various forms of benefits of genomic and biobanking research and opined that such benefits should be fairly and equitably shared with low and middle-income country researchers and their institutions, and research communities. The perceived barriers to the fair benefit sharing unfavorable include power disparities, weak research regulatory frameworks, and lack of scientific integrity. Conclusion: Overall, respondents believed that the distribution of the advantages of genomic and biobanking research in North-South collaborative research was not equitable nor fair, and that the playing field was not leveled. Therefore, we advocate the following for fair and equitable benefit sharing: Building the capacities and empowering research scientists in developing nations; strengthening regulatory frameworks and extending the purview of the research ethics committee in the development and implementation of material transfer agreements; and meaningfully involving local research communities in benefit sharing negotiations.

Experiences and practices of key research team members in obtaining informed consent for pharmacogenetic research among people living with HIV: a qualitative study.

This study aimed to explore experiences and practices of key research team members in obtaining informed consent for pharmacogenetics research and to identify the approaches used for enhancing understanding during the consenting process. Data collection involved 15 qualitative, in-depth interviews with key researchers who were involved in obtaining informed consent from HIV infected individuals in Uganda for participation in pharmacogenetic clinical trials. The study explored two prominent themes: approaches used to convey information and enhance research participants' understanding and challenges faced during the consenting process. Several barriers and facilitators for obtaining consent were identified. Innovative and potentially effective consenting strategies were identified in this study that should be studied and independently verified.

Understanding of Critical Elements of Informed Consent in Genomic Research: A Case of a Paediatric HIV-TB Research Project in Uganda.

Several studies have reported inadequate comprehension of informed consent for genomic research. This study aimed to assess research participants' understanding of critical elements of informed consent for genomic research. A cross-sectional survey involving 123 parents/caregivers of children participating in a paediatric genomic TB/HIV study was conducted. Only 47.2% of the participants had adequate understanding of consent information. The mean objective (actual) and subjective (perceived) understanding scores were 78.7% and 91.7% respectively. Participants adequately understood most elements of consent however, some elements were poorly understood including foreseeable risks, protection of confidentiality and compensation for research related injury. Overall there was inadequate comprehension of critical elements of informed consent and there was dissonance between actual and perceived comprehension of informed consent.

Ethical, Legal, and Sociocultural Issues in the Use of Mobile Technologies and Call Detail Records Data for Public Health in the East African Region: Scoping Review.

BACKGROUND: The exponential scale and pace of real-time data generated from mobile phones present opportunities for new insights and challenges across multiple sectors, including health care delivery and public health research. However, little attention has been given to the new ethical, social, and legal concerns related to using these mobile technologies and the data they generate in Africa. OBJECTIVE: The objective of this scoping review was to explore the ethical and related concerns that arise from the use of data from call detail records and mobile technology interventions for public health in the context of East Africa. METHODS: We searched the PubMed database for published studies describing ethical challenges while using mobile technologies and related data in public health research between 2000 and 2020. A predefined search strategy was used as inclusion criteria with search terms such as "East Africa," "mHealth," "mobile phone data," "public health," "ethics," or "privacy." We screened studies using prespecified eligibility criteria through a two-stage process by two independent reviewers. Studies were included if they were (1) related to mobile technology use and health, (2) published in English from 2000 to 2020, (3) available in full text, and (4) conducted in the East African region. We excluded articles that (1) were conference proceedings, (2) studies presenting an abstract only, (3) systematic and literature reviews, (4) research protocols, and (5) reports of mobile technology in animal subjects. We followed the five stages of a published framework for scoping reviews recommended by Arksey and O'Malley. Data extracted included title, publication year, target population, geographic region, setting, and relevance to mobile health (mHealth) and ethics. Additionally, we used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Extension for Scoping Reviews checklist to guide the presentation of this scoping review. The rationale for focusing on the five countries in East Africa was their geographic proximity, which lends itself to similarities in technology infrastructure development. RESULTS: Of the 94 studies identified from PubMed, 33 met the review inclusion criteria for the final scoping review. The 33 articles retained in the final scoping review represent studies conducted in three out of five East African countries: 14 (42%) from Uganda, 13 (39%) from Kenya, and 5 (16%) from Tanzania. Three main categories of concerns related to the use of mHealth technologies and mobile phone data can be conceptualized as (1) ethical issues (adequate informed consent, privacy and confidentiality, data security and protection), (2) sociocultural issues, and (3) regulatory/legal issues. CONCLUSIONS: This scoping review identified major cross-cutting ethical, regulatory, and sociocultural concerns related to using data from mobile technologies in the East African region. A comprehensive framework that accounts for the critical concerns raised would be valuable for guiding the safe use of mobile technology data for public health research purposes.

Developing digital contact tracing tailored to haulage in East Africa to support COVID-19 surveillance: a protocol.

INTRODUCTION: At the peak of Uganda's first wave of SARS-CoV-2 in May 2020, one in three COVID-19 cases was linked to the haulage sector. This triggered a mandatory requirement for a negative PCR test result at all ports of entry and exit, resulting in significant delays as haulage drivers had to wait for 24-48 hours for results, which severely crippled the regional supply chain.To support public health and economic recovery, we aim to develop and test a mobile phone-based digital contact tracing (DCT) tool that both augments conventional contact tracing and also increases its speed and efficiency. METHODS AND ANALYSIS: To test the DCT tool, we will use a stratified sample of haulage driver journeys, stratified by route type (regional and local journeys).We will include at least 65% of the haulage driver journeys ~83 200 on the network through Uganda. This allows us to capture variations in user demographics and socioeconomic characteristics that could influence the use and adoption of the DCT tool. The developed DCT tool will include a mobile application and web interface to collate and intelligently process data, whose output will support decision-making, resource allocation and feed mathematical models that predict epidemic waves.The main expected result will be an open source-tested DCT tool tailored to haulage use in developing countries.This study will inform the safe deployment of DCT technologies needed for combatting pandemics in low-income countries. ETHICS AND DISSEMINATION: This work has received ethics approval from the School of Public Health Higher Degrees, Research and Ethics Committee at Makerere University and The Uganda National Council for Science and Technology. This work will be disseminated through peer-reviewed publications, our websites https://project-thea.org/ and Github for the open source code https://github.com/project-thea/.

Researchers' perspectives on return of individual genetics results to research participants: a qualitative study.

Genetic results are usually not returned to research participants in Uganda despite their increased demand. We report on researchers' perceptions and experiences of return of individual genetic research results. The study involved 15 in-depth interviews of investigators involved in genetics and/or genomic research. A thematic approach was used to interpret the results. The four themes that emerged from the data were the need for return of individual results including incidental findings, community engagement and the consenting process, implications and challenges to return of individual results. While researchers are willing to return clinically significant genetic results to research participants, they remain unsure of how this should be implemented. Suggestions to aid implementation of return of results included reconsenting of participants before receiving individual genetic results and increasing access to genetic counseling services. Community engagement to determine community perceptions and individual preferences for the return of results, and also prepare participants to safely receive results emerged as another way to support return of results. Researchers have a positive attitude toward the return of clinically significant genetic results to research participants. There is need to develop national guidance on genetic research and also build capacity for clinical genetics and genetic counseling.

Low bone mass in people living with HIV on long-term anti-retroviral therapy: A single center study in Uganda.

BACKGROUND: This study set out to determine the prevalence of low bone mass following long-term exposure to antiretroviral therapy in Ugandan people living with HIV. METHODS: A cross-sectional study was conducted among 199 people living with HIV that had been on anti-retroviral therapy for at least 10 years. All participants had dual X-ray absorptiometry to determine their bone mineral density. The data collected included antiretroviral drug history and behavioral risk data Descriptive statistics were used to summarize the data. Inferential statistics were analyzed using multilevel binomial longitudinal Markov chain Monte Carlo mixed multivariate regression modelling using the rstanarm package. RESULTS: One hundred ninety nine adults were enrolled with equal representation of males and females. The mean age was 39.5 (SD 8.5) years. Mean durations on anti-retroviral treatment was 12.1 (SD 1.44) years, CD4 cell count was 563.9 cells/mm3. 178 (89.5%) had viral suppression with <50 viral copies/ml. There were 4 (2.0%) and 36 (18%) participants with low bone mass of the hip and lumbar spine respectively. Each unit increase in body mass index was associated with a significant reduction in the odds for low bone mineral density of the hip and lumbar spine. The duration on and exposure to the various antiretroviral medications had no significant effect on the participant's odds for developing low bone mass. All the coefficients of the variables in a multivariable model for either hip or lumbar spine bone mass were not significant. CONCLUSION: These results provide additional evidence that patients on long term ART achieve bone mass stabilization. Maintaining adequate body weight is important in maintaining good bone health in people on antiretroviral therapy.

Charcot arthropathy of the diabetic foot in a sub-Saharan tertiary hospital: a cross-sectional study.

BACKGROUND: Charcot foot arthropathy is a potentially limb-threatening condition that leads to progressive destruction of the bones and joints in the neuropathic foot. One of its main causes is diabetes mellitus whose prevalence is steadily increasing. The acute phase is often misdiagnosed thus leading to foot deformity, ulceration and increased risk of amputation. There is a paucity of literature on this condition from sub-Saharan Africa. This study aimed at determining the extent of Charcot foot arthropathy, the radiological patterns of Charcot foot arthropathy and patient's factors associated with Charcot foot arthropathy among adult patients with longstanding diabetes in an African setting. METHODS: This was a cross-sectional study that was carried at a national referral and university teaching hospital in Kampala, Uganda. One hundred patients with longstanding diabetes mellitus were consecutively recruited. Patients with a history of having diabetes mellitus for at least seven years since diagnosis were considered to have a longstanding disease. Clinical assessment of both feet was done. Weight-bearing radiographs of the selected foot were taken and evaluated using the Sanders and Frykberg and modified Eichenholtz classifications. A blood sample was taken for glycosylated haemoglobin (HbA1c). Data were summarized using descriptive statistics and student t-test. RESULTS: The proportion of Charcot foot arthropathy among patients with longstanding diabetes was 12% of which one-third (4 out of 12) were acute cases. Fifty percent of the lesions were in the forefoot and 50% in the midfoot. Seventeen percent of lesions were at the inflammatory stage of the modified Eichenholtz classification, 50% at the developmental stage, 25% at the healing stage, and 8% at the remodelling stage. An abnormal foot radiograph was significantly associated with Charcot foot arthropathy among patients with longstanding diabetes. CONCLUSION: Charcot foot arthropathy is fairly common in patients with longstanding diabetes mellitus in these settings with one third of patients presenting in the early acute phase. An abnormal weight-bearing radiograph was an associated factor of Charcot foot arthropathy among this specific group of patients. To reduce on the morbidity and limb threatening sequelae of this condition, clinicians are therefore advised to routinely examine the feet of patients with diabetes and send those with suspicious signs and symptoms for radiographic assessment.

Students' perspectives of undergraduate research methods education at three public medical schools in Uganda.

INTRODUCTION: In this study we used a model of adult learning to explore undergraduate students' views on how to improve the teaching of research methods and biostatistics. METHODS: This was a secondary analysis of survey data of 600 undergraduate students from three medical schools in Uganda. The analysis looked at student's responses to an open ended section of a questionnaire on their views on undergraduate teaching of research methods and biostatistics. Qualitative phenomenological data analysis was done with a bias towards principles of adult learning. RESULTS: Students appreciated the importance of learning research methods and biostatistics as a way of understanding research problems; appropriately interpreting statistical concepts during their training and post-qualification practice; and translating the knowledge acquired. Stressful teaching environment and inadequate educational resource materials were identified as impediments to effective learning. Suggestions for improved learning included: early and continuous exposure to the course; more active and practical approach to teaching; and a need for mentorship. CONCLUSION: The current methods of teaching research methods and biostatistics leave most of the students in the dissonance phase of learning resulting in none or poor student engagement that results in a failure to comprehend and/or appreciate the principles governing the use of different research methods.

Traumatic spondyloptosis of the lumbar spine: a case report.

INTRODUCTION: Spondyloptosis is the most severe of translation spine injuries. It results in complete disruption of the structural elements of the vertebral column and the adjacent paravertebral soft tissues, culminating in severe biomechanical instability. Although several cases of lumbosacral spondyloptosis have been documented, not many cases of traumatic lumbar spondyloptosis have been published in the literature. CASE PRESENTATION: We present a case of a 34-year-old man of Nilo-Hamitic ethnicity who presented to our unit with paraplegia following injury from the collapse of a concrete wall. Radiographic images showed spondyloptosis at the fourth lumbar vertebral level. He underwent surgery where decompression, reduction, posterior instrumentation and bone grafting through a posterior approach were done. He started regaining motor power 48 hours postoperatively. He is currently undergoing rehabilitation and is steadily improving, 2 months postoperatively. CONCLUSIONS: In limited-resource settings there is a tendency of "skilful neglect" of complex injuries. Where resources allow, surgical reconstruction of spondyloptosis should be attempted irrespective of the severity of the initial neurological deficit because there are chances of neurological improvement.

Musculoskeletal disorders among nursing staff: a comparison of five hospitals in Uganda.

INTRODUCTION: Low and middle income countries have severe nursing staff shortages which is associated with risk of poor quality of patient care and increased patient exposure to adverse events. This is accompanied with increased risk of musculoskeletal disorders to the nursing staff. This paper sets out to identify and compare factors associated with musculoskeletal disorders among nursing staff in 5 different hospitals in Uganda. METHODS: This was a cross sectional study on nurses from 5 different hospitals in Uganda. The study used a 12 month recall of reported Musculoskeletal disorders (MSD) among nurses. Ethical approval was obtained. Logistic regression analysis and ANOVA were used. The level of significance was set at 0.05 for all statistical tests. RESULTS: There were 755 respondents of whom 433 (58.4%) were nurses. The prevalence of MSD at anybody site was 80.8%. There were significant differences in reported MSD among nursing staff across different hospital settings which were worse in the public hospitals as compared to the private and private not for profit hospitals (p <0.001). Age (adjusted OR 1.03, 95% CI 1.01-1.06), self reported poor general health status (adj OR 4.5, 95% CI 2.8-7.24) and stress as suggested by waking up tired in the morning (adj OR 3.4, 95% CI 2.17-5.32) were significant associated factors for MSD in this population. CONCLUSION: Reported MSD among nursing staff across 5 different hospitals is worse in public as compared to private hospitals. Age, self reported poor general health status and stress were important factors for MSD in this population.

Mycotic aneurysm of the femoral artery resulting from mismanagement of a pathological femur fracture due to chronic osteomyelitis: a case report.

INTRODUCTION: Mycotic aneurysms are rarely listed among the possible complications of osteomyelitis of the long bones. To the best of our knowledge this is the first case of chronic osteomyelitis associated with a pathological fracture of the femur and a mycotic aneurysm of the femoral artery. CASE PRESENTATION: We present the case of a 13-year-old Ugandan boy who was referred to our hospital with chronic osteomyelitis associated with a pathological fracture of the right femur and a mycotic aneurysm of the femoral artery. He underwent a successful above-knee amputation and is currently undergoing rehabilitation. CONCLUSIONS: Aneurysms associated with chronic osteomyelitis of the long bones are very rare. However, in Africa, where people often still believe in crude traditional remedies, they should be considered among the possible diagnoses especially where acute injuries of the limbs are massaged and manipulated.

Microvascular system of the lumbar dorsal root ganglia in rats. Part I: a 3D analysis with scanning electron microscopy of vascular corrosion casts.

OBJECT: So far, the morphological features of the vascular system supplying the dorsal root ganglion (DRG) have been inferred only from microangiograms. However, in the past most of these studies lacked 3D observations. This study presents the details of the microvasculature of the lumbar DRG visualized by scanning electron microscopy of vascular corrosion casts. METHODS: Wistar rats were anesthetized with intraperitoneal sodium pentobarbital. After thoracotomy, the vascular system was perfused with heparinized saline, and Mercox resin was injected into the thoracic aorta. After polymerization of the resin, the vascular casts were macerated with potassium hydroxide, washed with water, and dried. The casts were examined with a scanning electron microscope. RESULTS: The vascular cast of the DRG was observed to have a higher density of vessels than the nerve root. Bifurcation or anastomoses of capillaries took place at approximately right angles, in a T-shaped pattern. Within the DRG, both the arterial supply and the capillary network contained blood flow control structures (ring-shaped constrictions in the cast probably representing a vascular sphincter in the microvessel). Three types of vessels could be distinguished: tortuous, straight, and bead-like capillaries. The dilations, bulges, and tortuousness of capillaries could serve the function of locally increasing the capillary surface area in a sensory neuron. CONCLUSIONS: The results of this study suggest a causal relationship between the metabolic demands of local neuronal activity and both the density of the capillary network and the placement of the blood flow control structures.

Microvascular system of the lumbar dorsal root ganglia in rats. Part II: neurogenic control of intraganglionic blood flow.

OBJECT: The dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG. METHODS: Ten Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromatic L-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope. RESULTS: In the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E-positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation. CONCLUSIONS: The presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

Vasomotion of intraradicular microvessels in rat.

STUDY DESIGN: This study is to investigate the changes of vasomotion of intraradicular microvessels in vivo. OBJECTIVE: We have observed microvascular corrosion casts of the lumbar nerve root by scanning electron microscopy and used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerve in blood vessels of the nerve root. SUMMARY OF BACKGROUND DATA: It is generally considered that the genesis of radiculopathy associated with the degenerative conditions of the spine may result from both mechanical compression and circulatory disturbance. However, the neurogenic control of intraradicular blood flow has received little attention in the past. METHODS: For three-dimensional observation of intraradicular vessels, we used scanning electron microscopic examination of microvascular corrosion casts in ten Wister rats. To investigate the mechanism of vasomotion of the nerve root, we used immunohistochemical methods. The sections were incubated overnight with antisera to tyrosine hydroxylase, choline acetyl transferase, substance P, calcitonin-gene-related peptide, vasoactive intestinal peptide, somatostatin, neuropeptide Y, leucine-enkephalin, cholecystokinin octapeptide, brain-nitric oxide synthase, and endothelium-nitric oxide synthase. Abidin-biotin complex method was used as the immunohistochemical procedure and the sections were observed under the light microscope. RESULTS: The general view of whole vascular casts of the lumbar spinal cord and nerve roots showed a high density of vessels. Bifurcation or anastomoses of capillaries approximately took place at right angles in a T-shaped pattern and capillaries showed a lot of ring-like compressions. This ring-like compression on the cast may represent a vascular sphincter in the microvessels. This study also reveals the existence of perivascular adrenergic, cholinergic, peptidergic, and nitroxydergic innervation with a possible role in neurogenic regulation of nerve root circulation. CONCLUSION: Perivascular nerve plexuses around intraradicular microvessels suggest that the autonomic nerves play an important role in intraradicular circulation.