Effect of the COVID-19 pandemic on blood donations and transfusions in Nigeria - A multi-facility study of 34 tertiary hospitals.

Background: The coronavirus disease 2019 (COVID-19) pandemic affected blood supplies globally. Mobile blood drive campaigns halted, and voluntary blood donations reduced, challenging available blood supplies. Furthermore, fears of virus transmission led to deferrals of elective surgeries and non-urgent clinical procedures with noticeable declines in blood donations and transfusions. Aims: We aimed to assess the effect of the COVID-19 pandemic on the number of blood donations and transfusions across the country by blood product type across various hospital departments. Materials and Methods: A retrospective descriptive study was conducted to determine the impact of the COVID-19 pandemic on blood services in 34 tertiary hospitals in Nigeria, comparing January to July 2019 (pre-COVID-19) to January to July 2020 (peri-COVID-19). Data were collected from the country's web-based software District Health Information System, Version 2 (DHIS2). Results: A 17.1% decline in numbers of blood donations was observed over the study period, especially in April 2020 (44.3%), a 21.7% decline in numbers of blood transfusions, especially in April 2020 (44.3%). The largest declines in transfusion were noted in surgery department for fresh frozen plasma (80.1%) [p = 0.012] and accident and emergency department transfusion of platelets (78.3%) [p = 0.005]. The least decline of statistical significance was observed in internal medicine transfusions of whole blood (19.6%) [p = 0.011]. Conclusions: The COVID-19 pandemic significantly affected the numbers of blood donations and transfusions in Nigeria. Strengthening blood services to provide various blood components and secure safe blood supplies during public health emergencies is therefore critical.

South African traditional values and beliefs regarding informed consent and limitations of the principle of respect for autonomy in African communities: a cross-cultural qualitative study.

BACKGROUND: The Western-European concept of libertarian rights-based autonomy, which advocates respect for individual rights, may conflict with African cultural values and norms. African communitarian ethics focuses on the interests of the collective whole or community, rather than rugged individualism. Hence collective decision-making processes take precedence over individual autonomy or consent. This apparent conflict may impact informed consent practice during biomedical research in African communities and may hinder ethical principlism in African bioethics. This study explored African biomedical researchers' perspectives regarding informed consent and potential limitations to the principle of respect for autonomy in African communities. METHODS: We conducted a qualitative study based on in-depth interviews with 12 biomedical researchers, five females and seven males aged 34 to 74 years, currently working at an African university. Interviews lasted 35-40 min each and involved semi-structured open-ended interviews, which allowed participants to offer information about their perceptions and feelings regarding respect for autonomy and informed consent as practised in Africa. Empirical data from the interviews were recorded, transcribed, and analysed using thematic content analysis, together with an interrogation of relevant scientific literature about African communitarian ethics, making evaluations and drawing inferences consistent with the empirical bioethics approach. RESULTS: Based on these interviews and analysis of relevant literature, we found that informed consent is difficult to apply in an African context because it derives from a Western conception of libertarian rights-based autonomy. Most respondents pointed out that it was challenging to implement informed consent in the African setting. Furthermore, communalism, customary beliefs, spirituality, and relational autonomy are predominant in most African communities, as exemplified by the African moral philosophies of Ubuntu/Botho and Ukama, which emphasize communitarianism over individual rights. We also found that language, education, poverty, and cultural beliefs are barriers to obtaining proper informed consent in African communities. CONCLUSIONS: We conclude that there are limitations to applying the principle of respect for autonomy and informed consent in African communities, especially in the context of human biomedical research. We recommend using a more relational approach, such as Ross's prima facie duties, to implement informed consent in African communities.

Doctor and healthcare workers strike: are they ethical or morally justifiable: another view.

PURPOSE OF REVIEW: This review analyzed legal and ethical issues surrounding recent doctor and healthcare worker (HCW) strikes and considered whether HCW strikes are legally and morally justifiable, underlying causes, and impact of such strikes on healthcare service delivery. RECENT FINDINGS: Recent reports show that doctor and HCW strikes are an ongoing phenomenon globally, occurring in both developed and developing countries. The main reasons for HCW strikes are failed employer-employee negotiations regarding fair wages and working conditions, policy issues, infrastructural deficiencies in poorer countries, and concerns by HCWs regarding personal security in the workplace. The main impact of HCW strikes is disruption of healthcare service delivery, such as canceled outpatients' appointments, hospital admissions, and elective surgeries. There was no clear evidence of increased patients' mortality during strikes, except in isolated cases, where emergency services were also withdrawn during strikes. SUMMARY: Doctors and HCWs strikes are lawful deadlock-breaking mechanisms when collective bargaining negotiations have reached an impasse. Doctors' strikes appear to create an ethical conflict with the Hippocratic tradition and obligation to place patients' best interests as the primary moral consideration in medical practice. However, the rise of consumerism in healthcare, and loss of power by doctors, many of whom now work as employees, subject to regulations imposed by different stakeholders, including governments, health-maintenance organizations, and healthcare insurers, has impacted on modern medical practice. Therefore, doctors, like other employees may occasionally resort to strikes to extract concessions from employers. Mortality is rarely increased during HCW strikes, especially where emergency healthcare services are provided.

Face processing in adolescents with positive and negative threat bias.

BACKGROUND: Individuals with anxiety disorders exhibit a 'vigilance-avoidance' pattern of attention to threatening stimuli when threatening and neutral stimuli are presented simultaneously, a phenomenon referred to as 'threat bias'. Modifying threat bias through cognitive retraining during adolescence reduces symptoms of anxiety, and so elucidating neural mechanisms of threat bias during adolescence is of high importance. We explored neural mechanisms by testing whether threat bias in adolescents is associated with generalized or threat-specific differences in the neural processing of faces. METHOD: Subjects were categorized into those with (n = 25) and without (n = 27) threat avoidance based on a dot-probe task at average age 12.9 years. Threat avoidance in this cohort has previously been shown to index threat bias. Brain response to individually presented angry and neutral faces was assessed in a separate session using functional magnetic resonance imaging. RESULTS: Adolescents with threat avoidance exhibited lower activity for both angry and neutral faces relative to controls in several regions in the occipital, parietal, and temporal lobes involved in early visual and facial processing. Results generalized to happy, sad, and fearful faces. Adolescents with a prior history of depression and/or an anxiety disorder had lower activity for all faces in these same regions. A subset of results replicated in an independent dataset. CONCLUSIONS: Threat bias is associated with generalized, rather than threat-specific, differences in the neural processing of faces in adolescents. Findings may aid in the development of novel treatments for anxiety disorders that use attention training to modify threat bias.

Evaluating the quality of informed consent and contemporary clinical practices by medical doctors in South Africa: an empirical study.

BACKGROUND: Informed consent is a legal and ethical doctrine derived from the principle of respect for autonomy. Generally two rights derived from autonomy are accorded legal protection. The constitutional right to bodily integrity followed by the right to bodily well-being, protected by professional negligence rules. Therefore healthcare professionals treating patients' without valid consent may be guilty of infringing patients' rights. Many challenges are experienced by doctors obtaining informed consent in complex multicultural societies like South Africa. These include different cultural ethos, multilingualism, poverty, education, unfamiliarity with libertarian rights based autonomy, and power asymmetry between doctors and patients. All of which could impact on the ability of doctors to obtain legally valid informed consent. METHODS: The objective of this study was to evaluate whether the quality of informed consent obtained by doctors practicing in South Africa is consistent with international ethical standards and local regulations. Responses from 946 participants including doctors, nurses and patients was analyzed, using a semi-structured self-administered questionnaire and person triangulation in selected public hospitals in Durban, KwaZulu-Natal, South Africa. RESULTS: The median age of 168 doctors participating was 30 years with 51% females, 28% interns, 16% medical officers, 26% registrars, 30% consultant/specialists. A broad range of clinical specialties were represented. Challenges to informed consent practice include language difficulties, lack of interpreters, workload, and time constraints. Doctors spent 5-10 minutes on consent, disclosed most information required to patients, however knowledge of essential local laws was inadequate. Informed consent aggregate scores (ICAS) showed that interns/registrars scored lower than consultants/specialists. ICAS scores were statistically significant by specialty (p = 0.005), with radiologists and anaesthetists scoring lowest, while internists, GPs and obstetricians/gynaecologists scored highest. Comparative ICAS scores showed that professional nurses scored significantly lower than doctors (p ≤ 0.001). CONCLUSIONS: This study shows that though doctors had general knowledge of informed consent requirements, execution in practice was inadequate, with deficiency in knowledge of basic local laws and regulations. Remedying identified deficiencies may require a 'corps' of interpreters in local hospitals to assist doctors in dealing with language difficulties, and continuing education in medical law and ethics to improve informed consent practices and overall quality of healthcare service delivery.

Global medicine: is it ethical or morally justifiable for doctors and other healthcare workers to go on strike?

BACKGROUND: Doctor and healthcare worker (HCW) strikes are a global phenomenon with the potential to negatively impact on the quality of healthcare services and the doctor-patient relationship. Strikes are a legitimate deadlock breaking mechanism employed when labour negotiations have reached an impasse during collective bargaining. Striking doctors usually have a moral dilemma between adherence to the Hippocratic tenets of the medical profession and fiduciary obligation to patients. In such circumstances the ethical principles of respect for autonomy, justice and beneficence all come into conflict, whereby doctors struggle with their role as ordinary employees who are rightfully entitled to a just wage for just work versus their moral obligations to patients and society. DISCUSSION: It has been argued that to deny any group of workers, including "essential workers" the right to strike is akin to enslavement which is ethically and morally indefensible. While HCW strikes occur globally, the impact appears more severe in developing countries challenged by poorer socio-economic circumstances, embedded infrastructural deficiencies, and lack of viable alternative means of obtaining healthcare. These communities appear to satisfy the criteria for vulnerability and may be deserving of special ethical consideration when doctor and HCW strikes are contemplated. SUMMARY: The right to strike is considered a fundamental right whose derogation would be inimical to the proper functioning of employer/employee collective bargaining in democratic societies. Motivations for HCW strikes include the natural pressure to fulfil human needs and the paradigm shift in modern medical practice, from self-employment and benevolent paternalism, to managed healthcare and consumer rights. Minimizing the incidence and impact of HCW strikes will require an ethical approach from all stakeholders, and recognition that all parties have an equal moral obligation to serve the best interests of society. Employers should implement legitimate collective bargaining agreements in a timely manner and high-handed actions such as mass-firing of striking HCWs, or unjustifiable disciplinary action by regulators should be avoided. Minimum service level agreements should be implemented to mitigate the impact of HCW strikes on indigent populations. Striking employees including HCWs should also desist from making unrealistic wage demands which could bankrupt governments/employers or hamper provision of other equally important social services to the general population.

Viewpoint discrimination and contestation of ideas on its merits, leadership and organizational ethics: expanding the African bioethics agenda.

The 3rd Pan-African Ethics Human Rights and Medical Law (3rd EHRML) conference was held in Johannesburg on July 7, 2013, as part of the Africa Health Congress. The conference brought together bioethicists, researchers and scholars from South Africa, Zimbabwe, Kenya and Nigeria working in the field of bioethics as well as students and healthcare workers interested in learning about ethical issues confronting the African continent. The conference which ran with a theme of "Bioethical and legal perspectives in biomedical research and medical practice in Africa with a focus on: Informed consent, HIV-AIDS & Tuberculosis, leadership & organizational ethics, patients and healthcare workers rights," was designed to expand the dialogue on African bioethics beyond the traditional focus on research ethics and the ethical dilemmas surrounding the conduct of biomedical research in developing countries. This introductory article highlights some of areas of focus at the conference including issues of leadership, organizational ethics and patients and healthcare workers rights in Africa. We analyze the importance of free speech, public debate of issues, argumentation and the need to introduce the teaching and learning of ethics to students in Africa in accordance with UNESCO guidelines. This article also focuses on other challenges confronting Africa today from an ethical standpoint, including the issues of poor leadership and organizational ethics which are main contributors to the problems prevalent in African countries, such as poverty, poor education and healthcare delivery systems, terrorism, social inequities, infrastructural deficits and other forms of 'structural violence' confronting vulnerable African communities. We believe that each of the eight articles included in this supplement, which have been rigorously peer-reviewed are a good example of current research on bioethics in Africa, and explore some new directions towards broadening the African bioethics agenda as we move forward to a new dawn for Africa in the 21st century.

Stigmatization of people living with HIV/AIDS by healthcare workers at a tertiary hospital in KwaZulu-Natal, South Africa: a cross-sectional descriptive study.

BACKGROUND: The issue of stigma is very important in the battle against HIV/AIDS in Africa since it may affect patient attendance at healthcare centres for obtaining antiretroviral (ARV) medications and regular medical check-ups. Stigmatization creates an unnecessary culture of secrecy and silence based on ignorance and fear of victimization. This study was designed to determine if there is external stigmatization of people living with HIV and AIDS (PLWHA) by health care workers (HCWs) at a tertiary hospital in KwaZulu-Natal (KZN) province, South Africa. The study investigated the impact of knowledge of HIV/AIDS by HCWs on treatment of patients, as well as the comfort level and attitude of HCWs when rendering care to PLWHA. METHODS: A descriptive cross sectional study was designed to collect data using an anonymous self-administered structured questionnaire from 334 HCWs. The study was conducted in clinical departments of a large multidisciplinary 922-bed tertiary care teaching hospital in Durban, KZN. RESULTS: Overall HCWs had an above average knowledge about HIV/AIDS although some gaps in knowledge were identified. Tests of statistical significance showed that there was association between level of education and knowledge of HIV/AIDs (p ≤ 0.001); occupation and knowledge of HIV/AIDS (p ≤ 0.001); and gender and knowledge of HIV/AIDS (p = 0.004). Test for comfort level was only significant for gender, with males showing more comfort and empathy when dealing with PLWHA (p = 0.003). The study also revealed that patients were sometimes tested for HIV without informed consent before surgery, due to fear of being infected, and there was some gossiping about patients' HIV status by HCWs, thereby compromising patient confidentiality. The majority of HCWs showed a willingness to report incidents of stigmatization and discrimination to higher authorities, for better monitoring and control. CONCLUSIONS: Although knowledge, attitude and comfort level of HCWs taking care of PLWHA was above average, enforcement of existing antidiscrimination laws and continuing education in medical ethics and healthcare law, would greatly improve the performance of HCWs taking care of PLWHAs. More psychological support and counselling should be provided to HCWs, to further reduce the impact of stigmatization and discrimination against PLWHA.

Traditional Health Care Practitioners' Perspectives on Applying Informed Consent During African Traditional Medical Practice in Akwa Ibom State, Nigeria: A Cross-Sectional Qualitative Study.

Introduction: This study explored the perspectives of traditional health care practitioners (THPs) practicing in the areas of herbalism, bone setting, and traditional birth attendance, from Akwa Ibom state, Nigeria, on the possibility and implications of applying informed consent (IC) during African traditional medicine (ATM) practice. Methods: Semistructured interviews were conducted with 11 THPs, consisting of 5 herbalists, 3 traditional bone setters (TBS), and 3 traditional birth attendants (TBAs), who represented the diverse groups that the study intended to cover. In-depth interviews were conducted using a semistructured guide and were recorded, transcribed, and analyzed using thematic analysis with the assistance of NVivo® qualitative analysis software. Results: Participants were seven males (64%) and four females (36%), 35-67 years of age, with 5-25 years of experience as THPs. Forty-six percent of participants were herbalists (27%), TBS, and TBAs (27%). Most participants (82%) were Annang, and (18%) were Ibibio first-language speakers. Three major themes emerged from the data analysis: (i) Existing ethical framework related to IC, (ii) knowledge of consent, and (iii) application of IC during traditional medical practice. These themes and relevant subthemes were explored. All (100%) THPs agreed that it was essential to communicate risks and benefits while allowing patients to ask questions before treatment. All participants (100%) stated that risk communication is essential in ATM, whereas 36% said they communicated all therapy benefits to their patients. Respondents believed patients could make an informed choice if they had complete information disclosure. However, THPs in this study had limited knowledge of formal IC rules and regulations. Conclusions: This study revealed that THPs in this setting disclose a diagnosis, risks, some benefits, and treatment options to patients. Consent/agreement was obtained verbally and voluntarily during ATM practice, consistent with IC doctrine. THPs had limited knowledge of the critical elements of IC. However, they suggested that a form of IC that does not conflict with traditional African norms could be applicable in ATM. IC could facilitate documentation and help reduce risks in ATM practice.

Patients' Experience on Practice and Applicability of Informed Consent in Traditional Medical Practice in KwaZulu-Natal Province, South Africa.

BACKGROUND: Informed consent (IC) is constitutionally protected in South Africa based on individual rights to bodily integrity and well-being. In terms of the law, patients cannot be involved in medical treatment or research without IC. This study explored patients' experience on practice and applicability of IC in African traditional medicine (ATM) in Msunduzi and eThekwini municipalities, KwaZulu-Natal province, South Africa, to evaluate whether important elements of IC such as full information disclosure, capacity, understanding, and volition are considered or being applied during ATM. METHODS: This cross-sectional quantitative study was conducted using semistructured questionnaires administered to patients attending traditional health practitioners' (THPs') treatment centres. Stata V15.1 was used to analyse variables including descriptive and inferential data analysis. RESULTS: One hundred and twenty-nine (129) participants completed this study, of which 62% were females. Most participants were in the age range of 26-35 (38.8%). All respondents were IsiZulu home-language speakers, single (62.8%), employed (48%), and with some tertiary education (48.8%). Most patients were informed about their diagnosis (58.9%), treatment benefits (79.8%), and recommended treatment (79.8%). Fewer were informed about risks of treatment (36.4%), right of refusal (3.1%), and risks of refusing recommended treatment (0.8%). All participants reported satisfaction with information disclosed by the THPs and did not feel coerced to accept treatment. Consent was obtained verbally in all cases. The majority of participants (76.7%) sought surrogate assistance when consulting THPS, and 81.4% preferred being informed about all treatment risks. Most respondents also preferred involvement in healthcare decision-making during ATM. CONCLUSION: This study reveals that most patients consulting THPs in the KwaZulu-Natal province for treatment are aware of their right to information disclosure and the need to reach agreement before involvement in ATM treatment procedures. The study also showed that some key elements of IC are currently being applied during ATM practice in South Africa.

Protective effect of Cyperus esculentus (tiger nut) extract against scopolamine-induced memory loss and oxidative stress in mouse brain.

Objectives The juice extract of Cyperus esculentus commonly known as tiger nuts (TINUT) is widely used for its numerous health promoting effects including alleviation of symptoms associated with neurological disorders. Herein, we investigated the influence of the aqueous extract of C. esculentus on cognitive disorder and the underlying changes in acetylcholinesterase (AChE) activity and oxidative stress biomarkers in mice exposed to scopolamine. Methods C. esculentus (50-200 mg/kg) or saline (10 mL/kg) was given alone or with scopolamine 30 min after, to male Swiss mice (6/group) daily for seven days. We evaluated the cognitive performance using Y-maze and object recognition on day seven post-treatment. Brains of the animals were afterwards processed for spectrophotometric determination of AChE activity and contents of oxidative stress biomarkers (malondialdehyde [MDA], glutathione [GSH], catalase, superoxide dismutase and nitrite). Results The extract improves cognitive function and also upturned scopolamine amnesia in mice. The extract markedly reduced brain AChE, MDA, and nitrite contents in mice injected with scopolamine (p<0.05). It also attenuated scopolamine-induced deregulated GSH contents and antioxidant enzymes in mouse brain. Conclusions The results of this study suggest that regular consumption of TINUT might offer beneficial effects in memory-related disorders.

Joint movements associated with minimum toe clearance variability in older adults during level overground walking.

BACKGROUND: Approximately one-third of falls are caused by the swing foot contacting an object or the ground, resulting in a trip. The increased incidence of trip-related falls among older adults may be explained by greater within-person minimum toe clearance (MTC) variability. RESEARCH QUESTION: Will kinematic variability at any of the 6 major joints in the lower limbs, individually or in combination, be associated with MTC variability? METHODS: This cross-sectional study investigated whether single or multiple joint movements best explained MTC variability in older adults. Twenty healthy older adults (7 males, 13 females; mean age = 71.3 ±â€¯7.2 years) were recruited. Participants were fitted with a modified Cleveland Clinic marker set and walked for 50 trials at self-selected speeds over a 7-meter walkway (with a rest at 25 trials) while 6 infrared cameras recorded kinematics. RESULTS: Seven joint movements were evaluated, and swing hip flexion-extension variability was the only joint movement significantly associated with MTC variability (r = 0.577, p = 0.008) and explained 29.6% (adjusted R2) of the variance of MTC variability in older adults (F (1, 18) = 8.897, p = 0.008). SIGNIFICANCE: Identifying the joint movement/s associated with inconsistencies in toe clearance will improve our understanding of endpoint control in older adults and may lead to the development of effective trip prevention strategies.

The first report of Histophilus somni pneumonia in Nigerian dairy cattle.

Clinical signs of severe bronchopneumonia, including anorexia, coughing, nasal discharge, dyspnoea, diarrhoea, distension of the neck, lethargy, recumbency, lameness preceding collapse, and death were observed among a herd of Holstein-Friesian dairy cattle. The outbreak occurred over a 30-day period, and attack and case-fatality rates were 0.4% and 50%, respectively. At necropsy, extensive consolidation in the cranioventral parts of the lungs was observed. Histologically, a severe acute bronchopneumonia with slight pleuritis was present. Both pathological and bacteriological evaluation of the lungs incriminated Histophilus somni (heavy growth). Supplementary laboratory investigations also isolated Clostridium and Klebsiella species (scanty growth) from the lungs. Histophilosis in cattle was confirmed for the first time in Nigeria.

Knowledge and practice of informed consent by physiotherapists and therapy assistants in KwaZulu-Natal Province, South Africa.

BACKGROUND: Informed consent is a doctrinal prerequisite in accordance with the National Health Act 2003 and professional ethical guidelines. Current regulations stipulate that healthcare professionals obtain informed consent from patients prior to treatment. Misconduct charges relating to inadequate information disclosure have been recorded against South African physiotherapists. OBJECTIVES: This study evaluated knowledge and barriers to informed consent practice among physiotherapists and assistants at Ethekwini District public health institutions. METHODS: This cross-sectional study utilised self-administered questionnaires. Statistical Package for Social Sciences was used to analyse variables. Significance level and attitude correlation was determined using chi-squared tests, Pearson's correlation and Spearman's coefficient. RESULTS: Forty-nine respondents (43 physiotherapists, 3 technicians, 3 assistants) completed this study. Mean age and professional experience of respondents were 38 and 14 years, respectively. The majority were female (93%); 56% spent 5 to 10 min obtaining informed consent, mostly verbally (89%); while 47% correctly identified age of consent to routine treatment (12 years). Information provided to patients by respondents included treatment benefits (100%), common risks (81%) and 'all material risks' (31%). Fifty per cent of respondents showed positive attitudes to informed consent. CONCLUSIONS: Some practising physiotherapists and assistants in KwaZulu-Natal public healthcare institutions had only partial knowledge of informed consent regulations and local laws. Barriers to informed consent included language and excessive workload. CLINICAL IMPLICATIONS: Patient-centred care is quality healthcare, and adequate informed consent knowledge improves clinical outcomes, respects patients' dignity and autonomy. Continued professional education on healthcare law and ethics should be provided to practising physiotherapists and assistants.

Better Respiratory Education and Treatment Help Empower (BREATHE) study: Methodology and baseline characteristics of a randomized controlled trial testing a transitional care program to improve patient-centered care delivery among chronic obstructive pulmonary disease patients.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of hospitalizations. Interventional studies focusing on the hospital-to-home transition for COPD patients are few. In the BREATHE (Better Respiratory Education and Treatment Help Empower) study, we developed and tested a patient and family-centered transitional care program that helps prepare hospitalized COPD patients and their family caregivers to manage COPD at home. METHODS: In the study's initial phase, we co-developed the BREATHE transitional care program with COPD patients, family-caregivers, and stakeholders. The program offers tailored services to address individual patients' needs and priorities at the hospital and for 3months post discharge. We tested the program in a single-blinded RCT with 240 COPD patients who were randomized to receive the program or 'usual care'. Program participants were offered the opportunity to invite a family caregiver, if available, to enroll with them into the study. The primary outcomes were the combined number of COPD-related hospitalizations and Emergency Department (ED) visits per participant at 6months post discharge, and the change in health-related quality of life over the 6months study period. Other measures include 'all cause' hospitalizations and ED visits; patient activation; self-efficacy; and, self-care behaviors. DISCUSSION: Unlike 1month transitional care programs that focus on patients' post-acute care needs, the BREATHE program helps hospitalized COPD patients manage the post discharge period as well as prepare them for long term self-management of COPD. If proven effective, this program may offer a timely solution for hospitals in their attempts to reduce COPD rehospitalizations.

Fluorescence-activated cell sorter analysis of bulk-isolated porcine oligodendrocytes.

We describe here the methods by which enriched populations of oligodendrocytes were isolated from adult porcine brains using Percoll density gradient centrifugation and their immunological properties analyzed by a fluorescence-activated cell sorter (FACS). The analyses by immunofluorescence microscopy and FACS indicated 95% and 93% purity of oligodendrocytes in the cell preparations when galactocerebroside antibody, an oligodendrocyte-specific marker, was employed. Further FACS analysis indicated that 90% of the cells with the forward angle light scatter characteristics of oligodendrocytes were immunolabelled by the monoclonal antibody HNK-1. The FACS sorting capability was then used to correlate the forward angle light scatter and propidium iodide uptake characteristics of our cell preparations to cell debris, erythrocytes as well as viable and non-viable oligodendrocytes. By gating on a multiparameter basis on both defined forward light scatter and positive galactocerebroside immunolabelling, oligodendrocyte populations exceeding 98% purity were obtained which were suitable for long-term culture and further immunological and neurobiological studies.

Suprachiasmatic nucleus projection to the medial prefrontal cortex: a viral transneuronal tracing study.

The viral transneuronal labeling method was used to examine whether the suprachiasmatic nucleus (SCN) is linked by multisynaptic connections to the medial prefrontal cortex of the rat. In separate experiments, pseudorabies virus (PRV) was injected into one of the three different cytoarchitectonic regions that comprise the medial prefrontal cortex: infralimbic (Brodmann area 25), prelimbic (Brodmann area 32), and cingulate (Brodmann area 24) cortical areas. After 4-days survival, extensive SCN transneuronal labeling was found following infralimbic cortex (ILC) injections, but almost none occurred when the PRV injections were centered in the prelimbic or cingulate areas. In the ILC cases, transneuronal labeling was localized mainly in the dorsomedial SCN, although a moderate number of labeled neurons were found in the ventrolateral SCN. About 13% of the infected neurons were vasopressin immunoreactive and 4% were vasoactive intestinal polypeptide-positive. Another set of experiments was performed in which the paraventricular thalamic nucleus (PVT) was destroyed 2 weeks prior to making PRV injections into the ILC. Almost no SCN transneuronal labeling occurred in these animals, suggesting that the SCN projection to the ILC is dependent on a relay in the PVT. We propose that the SCN sends timing signals, via its relay in the PVT, to the ILC. This pathway may modulate higher-level brain functions, such as attention, mood, or working memory. Assuming that a homologous circuit exists in humans, we speculate that neurochemical changes affecting this pathway may account for some of the symptoms associated with clinical depression and attention-deficit/hyperactivity disorder.

Photoresponsive Fischer 344 Rats are reproductively inhibited by melatonin and differ in 2-[125I] lodomelatonin binding from nonphotoresponsive Sprague-Dawley rats.

Many temperate-zone species use photoperiod as an environmental cue to regulate reproductive timing. Strains of laboratory rats differ in their responsiveness to photoperiod, with the Fischer 344 (F344) strain being the most responsive known. F344 rats and closely related strains that differ in photoresponsiveness may be useful models to study the mechanisms and genetic basis for photoresponsiveness. We tested two hypotheses: (i) that melatonin mediates photoresponsiveness in F344 rats, as is the case in all other mammals tested, and (ii) that the location, abundance, or affinity of melatonin receptors, as estimated by the amount and location of binding of the radioligand 2-[125I]-iodomelatonin (IMEL) in the brain, might cause variation in photoresponsiveness among rat strains. Melatonin injections 1 h before lights off in a stimulatory photoperiod (L14 : D10) induced reproductive inhibition and reduced weight gain in a manner similar to short days of L8 : D16, while injections of ethanolic saline vehicle did not. Interestingly, melatonin injections administered during an inhibitory photoperiod (L10 : D14) caused greater inhibition of both reproduction and weight gain than short photoperiod alone. Pinealectomized F344 rats implanted subcutaneously with melatonin in a silastic capsule did not differ in testis size or body weight from controls with blank implants. The brains and pars tuberalis of the pituitary from photoresponsive F344 rats and nonphotoresponsive Harlan Sprague-Dawley (HSD) rats were processed for autoradiography using IMEL. We found significantly higher specific IMEL binding in the anterior and posterior regions of the paraventricular nucleus of the thalamus (PVNt) and reuniens nucleus of the thalamus of F344 rats than in the same areas in HSD rats. There were no differences between strains in specific IMEL binding in the medial PVNt, anteroventral and anterodorsal nucleus of the thalamus, suprachiasmatic nucleus, or the pars tuberalis. These results indicate that melatonin mediates photoresponsiveness in F344 rats. In addition, they provide support for the hypothesis that F344 rats may be photoresponsive due to differences from other strains in the location, density, or affinity of melatonin receptors.

Children's concepts of the family.

The past decade has witnessed increased research emphasis on children's developing conceptions of their social environment. In the present study, 64 children in grades 1 through 6 were interviewed to examine age-related changes in their understanding of the concept of family. The study also explored whether children's developing conceptions of the family were mediated by their own family structures. Results indicated five levels of family concept understanding that reflected a growing (i.e., age-related) facility in children's application of kinship criteria across traditional and nontraditional family groupings. However, the sophistication of children's understanding of the family was not related to the structure of their own families. These findings suggest that children's level of cognitive development is more important for their comprehension of the family than the specific experiences derived from living within their own unique family. Implications of these findings for mental health professionals who work with families in transition are discussed.