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1.
J Infect Dis ; 224(12 Suppl 2): S691-S693, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34882204

RESUMO

Africa has the highest number of pregnant women with human immunodeficiency virus (HIV). In some studies, HIV has been associated with adverse perinatal outcomes. However, the pathophysiological mechanism leading to adverse fetal outcomes is not known. Maternal vascular malformation, chorioamnionitis, and decreased placental weight have been described as placental features associated with HIV in some studies. The use of antiretroviral therapy has reduced perinatal transmission of HIV and adverse fetal outcomes. However, placental mechanisms associated with HIV and the fetal immune response to maternal HIV infection are poorly understood. Additional research is required to understand whether altered maternal immunity in women living with HIV can trigger fetal responses leading to stillbirth or preterm birth.


Assuntos
Retardo do Crescimento Fetal/virologia , Infecções por HIV/complicações , Trabalho de Parto Prematuro/virologia , Placenta/patologia , Complicações Infecciosas na Gravidez/virologia , Nascimento Prematuro , Natimorto , Adulto , Terapia Antirretroviral de Alta Atividade , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/transmissão , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Placenta/virologia , Gravidez , Resultado da Gravidez
3.
Lancet Glob Health ; 8(7): e909-e919, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32562647

RESUMO

BACKGROUND: Sub-Saharan Africa and south Asia contributed 81% of 5·9 million under-5 deaths and 77% of 2·6 million stillbirths worldwide in 2015. Vital registration and verbal autopsy data are mainstays for the estimation of leading causes of death, but both are non-specific and focus on a single underlying cause. We aimed to provide granular data on the contributory causes of death in stillborn fetuses and in deceased neonates and children younger than 5 years, to inform child mortality prevention efforts. METHODS: The Child Health and Mortality Prevention Surveillance (CHAMPS) Network was established at sites in seven countries (Baliakandi, Bangladesh; Harar and Kersa, Ethiopia; Siaya and Kisumu, Kenya; Bamako, Mali; Manhiça, Mozambique; Bombali, Sierra Leone; and Soweto, South Africa) to collect standardised, population-based, longitudinal data on under-5 mortality and stillbirths in sub-Saharan Africa and south Asia, to improve the accuracy of determining causes of death. Here, we analysed data obtained in the first 2 years after the implementation of CHAMPS at the first five operational sites, during which surveillance and post-mortem diagnostics, including minimally invasive tissue sampling (MITS), were used. Data were abstracted from all available clinical records of deceased children, and relevant maternal health records were also extracted for stillbirths and neonatal deaths, to incorporate reported pregnancy or delivery complications. Expert panels followed standardised procedures to characterise causal chains leading to death, including underlying, intermediate (comorbid or antecedent causes), and immediate causes of death for stillbirths, neonatal deaths, and child (age 1-59 months) deaths. FINDINGS: Between Dec 10, 2016, and Dec 31, 2018, MITS procedures were implemented at five sites in Mozambique, South Africa, Kenya, Mali, and Bangladesh. We screened 2385 death notifications for inclusion eligibility, following which 1295 families were approached for consent; consent was provided for MITS by 963 (74%) of 1295 eligible cases approached. At least one cause of death was identified in 912 (98%) of 933 cases (180 stillbirths, 449 neonatal deaths, and 304 child deaths); two or more conditions were identified in the causal chain for 585 (63%) of 933 cases. The most common underlying causes of stillbirth were perinatal asphyxia or hypoxia (130 [72%] of 180 stillbirths) and congenital infection or sepsis (27 [15%]). The most common underlying causes of neonatal death were preterm birth complications (187 [42%] of 449 neonatal deaths), perinatal asphyxia or hypoxia (98 [22%]), and neonatal sepsis (50 [11%]). The most common underlying causes of child deaths were congenital birth defects (39 [13%] of 304 deaths), lower respiratory infection (37 [12%]), and HIV (35 [12%]). In 503 (54%) of 933 cases, at least one contributory pathogen was identified. Cytomegalovirus, Escherichia coli, group B Streptococcus, and other infections contributed to 30 (17%) of 180 stillbirths. Among neonatal deaths with underlying prematurity, 60% were precipitated by other infectious causes. Of the 275 child deaths with infectious causes, the most common contributory pathogens were Klebsiella pneumoniae (86 [31%]), Streptococcus pneumoniae (54 [20%]), HIV (40 [15%]), and cytomegalovirus (34 [12%]), and multiple infections were common. Lower respiratory tract infection contributed to 174 (57%) of 304 child deaths. INTERPRETATION: Cause of death determination using MITS enabled detailed characterisation of contributing conditions. Global estimates of child mortality aetiologies, which are currently based on a single syndromic cause for each death, will be strengthened by findings from CHAMPS. This approach adds specificity and provides a more complete overview of the chain of events leading to death, highlighting multiple potential interventions to prevent under-5 mortality and stillbirths. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Mortalidade da Criança , Vigilância da População/métodos , África Subsaariana/epidemiologia , Autopsia , Causas de Morte , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , África do Sul/epidemiologia
4.
J Comp Neurol ; 528(17): 2994-3007, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32112418

RESUMO

We quantified both proliferative (Ki-67 immunohistochemistry) and immature (doublecortin immunohistochemistry) cells within the dentate gyrus of adult Egyptian fruit bats from three distinct environments: (a) primary rainforest, (b) subtropical woodland, and (c) fifth-generation captive-bred. We used four different previously reported methods to assess the effect of the environment on proliferative and immature cells: (a) the comparison of raw totals of proliferative and immature cells; (b) these totals standardized to brain mass; (c) these totals expressed as a density using the volume of the granular cell layer (GCLv) for standardization; and (d) these totals expressed as a percentage of the total number of granule cells. For all methods, the numbers of proliferative cells did not differ statistically among the three groups, indicating that the rate of proliferation, while malleable to experimental manipulation or transiently in response to events of importance in the natural habitat, appears to occur, for the most part, at a predetermined rate within a species. For the immature cells, raw numbers and standardizations to brain mass and GCLv revealed no difference between the three groups studied; however, standardization to total granule cell numbers indicated that the two groups of wild-caught bats had significantly higher numbers of immature neurons than the captive-bred bats. These contrasting results indicate that the interpretation of the effect of the environment on the numbers of immature neurons appears method dependent. It is possible that current methods are not sensitive enough to reveal the effect of different environments on proliferative and immature cells.


Assuntos
Domesticação , Florestas , Hipocampo/crescimento & desenvolvimento , Neurogênese/fisiologia , Neurônios/fisiologia , Floresta Úmida , Fatores Etários , Animais , Quirópteros , Meio Ambiente , Feminino , Hipocampo/citologia , Imuno-Histoquímica/métodos , Masculino
5.
Clin Infect Dis ; 69(Suppl 4): S361-S373, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598659

RESUMO

BACKGROUND: Current estimates for causes of childhood deaths are mainly premised on modeling of vital registration and limited verbal autopsy data and generally only characterize the underlying cause of death (CoD). We investigated the potential of minimally invasive tissue sampling (MITS) for ascertaining the underlying and immediate CoD in children 1 month to 14 years of age. METHODS: MITS included postmortem tissue biopsies of brain, liver, and lung for histopathology examination; microbial culture of blood, cerebrospinal fluid (CSF), liver, and lung samples; and molecular microbial testing on blood, CSF, lung, and rectal swabs. Each case was individually adjudicated for underlying, antecedent, and immediate CoD by an international multidisciplinary team of medical experts and coded using the International Classification of Diseases, Tenth Revision (ICD-10). RESULTS: An underlying CoD was determined for 99% of 127 cases, leading causes being congenital malformations (18.9%), complications of prematurity (14.2%), human immunodeficiency virus/AIDS (12.6%), diarrheal disease (8.7%), acute respiratory infections (7.9%), injuries (7.9%), and malignancies (7.1%). The main immediate CoD was pneumonia, sepsis, and diarrhea in 33.9%, 19.7%, and 10.2% of cases, respectively. Infection-related deaths were either an underlying or immediate CoD in 78.0% of cases. Community-acquired pneumonia deaths (n = 32) were attributed to respiratory syncytial virus (21.9%), Pneumocystis jirovecii (18.8%), cytomegalovirus (15.6%), Klebsiella pneumoniae (15.6%), and Streptococcus pneumoniae (12.5%). Seventy-one percent of 24 sepsis deaths were hospital-acquired, mainly due to Acinetobacter baumannii (47.1%) and K. pneumoniae (35.3%). Sixty-two percent of cases were malnourished. CONCLUSIONS: MITS, coupled with antemortem clinical information, provides detailed insight into causes of childhood deaths that could be informative for prioritization of strategies aimed at reducing under-5 mortality.


Assuntos
Manejo de Espécimes/métodos , Adolescente , Autopsia/métodos , Causas de Morte , Criança , Pré-Escolar , Diagnóstico , Estudos Epidemiológicos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Projetos Piloto , Estudos Prospectivos , África do Sul
6.
Clin Infect Dis ; 69(Suppl 4): S342-S350, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598656

RESUMO

BACKGROUND: Despite approximately 2.6 million stillbirths occurring annually, there is a paucity of systematic biological investigation and consequently knowledge on the causes of these deaths in low- and middle-income countries (LMICs). We investigated the utility of minimally invasive tissue sampling (MITS), placental examination, and clinical history, in attributing the causes of stillbirth in a South African LMIC setting. METHODS: This prospective, observational pilot study undertook sampling of brain, lung, and liver tissue using core biopsy needles, blood and cerebrospinal fluid collection, and placental examination. Testing included microbial culture and/or molecular testing and tissue histological examination. The cause of death was determined for each case by an international panel of medical specialists and categorized using the World Health Organization's International Classification of Diseases, Tenth Revision application to perinatal deaths. RESULTS: A cause of stillbirth was identifiable for 117 of 129 (90.7%) stillbirths, including an underlying maternal cause in 63.4% (n = 83) and an immediate fetal cause in 79.1% (n = 102) of cases. The leading underlying causes of stillbirth were maternal hypertensive disorders (16.3%), placental separation and hemorrhage (14.0%), and chorioamnionitis (10.9%). The leading immediate causes of fetal death were antepartum hypoxia (35.7%) and fetal infection (37.2%), including due to Escherichia coli (16.3%), Enterococcus species (3.9%), and group B Streptococcus (3.1%). CONCLUSIONS: In this pilot, proof-of-concept study, focused investigation of stillbirth provided granular detail on the causes thereof in an LMIC setting, including provisionally highlighting the largely underrecognized role of fetal sepsis as a dominant cause.


Assuntos
Manejo de Espécimes/métodos , Causas de Morte , Feminino , Idade Gestacional , Humanos , Masculino , Morte Perinatal , Projetos Piloto , Placenta/patologia , Pré-Eclâmpsia/mortalidade , Gravidez , Complicações Infecciosas na Gravidez/mortalidade , Cuidado Pré-Natal/métodos , Estudo de Prova de Conceito , Estudos Prospectivos , África do Sul , Natimorto
7.
Clin Infect Dis ; 69(Suppl 4): S351-S360, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598660

RESUMO

BACKGROUND: Postmortem minimally invasive tissue sampling (MITS) is a potential alternative to the gold standard complete diagnostic autopsy for identifying specific causes of childhood deaths. We investigated the utility of MITS, interpreted with available clinical data, for attributing underlying and immediate causes of neonatal deaths. METHODS: This prospective, observational pilot study enrolled neonatal deaths at Chris Hani Baragwanath Academic Hospital in Soweto, South Africa. The MITS included needle core-biopsy sampling for histopathology of brain, lung, and liver tissue. Microbiological culture and/or molecular tests were performed on lung, liver, blood, cerebrospinal fluid, and stool samples. The "underlying" and "immediate" causes of death (CoD) were determined for each case by an international panel of 12-15 medical specialists. RESULTS: We enrolled 153 neonatal deaths, 106 aged 3-28 days. Leading underlying CoD included "complications of prematurity" (52.9%), "complications of intrapartum events" (15.0%), "congenital malformations" (13.1%), and "infection related" (9.8%). Overall, infections were the immediate or underlying CoD in 57.5% (n = 88) of all neonatal deaths, including the immediate CoD in 70.4% (58/81) of neonates with "complications of prematurity" as the underlying cause. Overall, 74.4% of 90 infection-related deaths were hospital acquired, mainly due to multidrug-resistant Acinetobacter baumannii (52.2%), Klebsiella pneumoniae (22.4%), and Staphylococcus aureus (20.9%). Streptococcus agalactiae was the most common pathogen (5/15 [33.3%]) among deaths with "infections" as the underlying cause. CONCLUSIONS: MITS has potential to address the knowledge gap on specific causes of neonatal mortality. In our setting, this included the hitherto underrecognized dominant role of hospital-acquired multidrug-resistant bacterial infections as the leading immediate cause of neonatal deaths.


Assuntos
Manejo de Espécimes/métodos , Autopsia/métodos , Causas de Morte , Feminino , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Masculino , Morte Perinatal , Projetos Piloto , Gravidez , Estudos Prospectivos , África do Sul , Natimorto
8.
Clin Infect Dis ; 69(Suppl 4): S333-S341, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598661

RESUMO

Mortality surveillance and cause of death data are instrumental in improving health, identifying diseases and conditions that cause a high burden of preventable deaths, and allocating resources to prevent these deaths. The Child Health and Mortality Prevention Surveillance (CHAMPS) network uses a standardized process to define, assign, and code causes of stillbirth and child death (<5 years of age) across the CHAMPS network. A Determination of Cause of Death (DeCoDe) panel composed of experts from a local CHAMPS site analyzes all available individual information, including laboratory, histopathology, abstracted clinical records, and verbal autopsy findings for each case and, if applicable, also for the mother. Using this information, the site panel ascertains the underlying cause (event that precipitated the fatal sequence of events) and other antecedent, immediate, and maternal causes of death in accordance with the International Classification of Diseases, Tenth Revision and the World Health Organization death certificate. Development and use of the CHAMPS diagnosis standards-a framework of required evidence to support cause of death determination-assures a homogenized procedure leading to a more consistent interpretation of complex data across the CHAMPS network. This and other standardizations ensures future comparability with other sources of mortality data produced externally to this project. Early lessons learned from implementation of DeCoDe in 5 CHAMPS sites in sub-Saharan Africa and Bangladesh have been incorporated into the DeCoDe process, and the implementation of DeCoDe has the potential to spur health systems improvements and local public health action.


Assuntos
Saúde da Criança/normas , Vigilância da População/métodos , África Subsaariana , Bangladesh , Causas de Morte , Criança , Mortalidade da Criança , Saúde Global/normas , Humanos , Padrões de Referência , Natimorto
9.
Clin Infect Dis ; 69(Suppl 4): S262-S273, 2019 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-31598664

RESUMO

Despite reductions over the past 2 decades, childhood mortality remains high in low- and middle-income countries in sub-Saharan Africa and South Asia. In these settings, children often die at home, without contact with the health system, and are neither accounted for, nor attributed with a cause of death. In addition, when cause of death determinations occur, they often use nonspecific methods. Consequently, findings from models currently utilized to build national and global estimates of causes of death are associated with substantial uncertainty. Higher-quality data would enable stakeholders to effectively target interventions for the leading causes of childhood mortality, a critical component to achieving the Sustainable Development Goals by eliminating preventable perinatal and childhood deaths. The Child Health and Mortality Prevention Surveillance (CHAMPS) Network tracks the causes of under-5 mortality and stillbirths at sites in sub-Saharan Africa and South Asia through comprehensive mortality surveillance, utilizing minimally invasive tissue sampling (MITS), postmortem laboratory and pathology testing, verbal autopsy, and clinical and demographic data. CHAMPS sites have established facility- and community-based mortality notification systems, which aim to report potentially eligible deaths, defined as under-5 deaths and stillbirths within a defined catchment area, within 24-36 hours so that MITS can be conducted quickly after death. Where MITS has been conducted, a final cause of death is determined by an expert review panel. Data on cause of death will be provided to local, national, and global stakeholders to inform strategies to reduce perinatal and childhood mortality in sub-Saharan Africa and South Asia.


Assuntos
Causas de Morte/tendências , Saúde da Criança/tendências , Mortalidade da Criança/tendências , África Subsaariana/epidemiologia , Ásia/epidemiologia , Autopsia/tendências , Criança , Saúde Global/tendências , Humanos , Vigilância da População/métodos , Natimorto/epidemiologia
10.
Lancet Glob Health ; 7(4): e503-e512, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30879510

RESUMO

BACKGROUND: About 2·6 million third-trimester stillbirths occur annually worldwide, mostly in low-income and middle-income countries, where the causes of these deaths are rarely investigated. METHODS: We did a prospective, hospital-based, observational study in Soweto, South Africa, to investigate the causes of stillbirths in fetuses of at least 22 weeks' gestational age or with a birthweight of at least 500 g. Maternal clinical information was abstracted from medical records. Investigations included placental macroscopic and histopathological examination and fetal blood culture (including screening for pathogenic bacteria associated with stillbirth). Cases missing one or more of these investigations were considered to have incomplete samples and were excluded from the analysis of cause of stillbirth. Causes of stillbirths were assessed by individual case reviews by at least two obstetricians, and classified with a modified Stillbirth Collaborative Research Network classification system. FINDINGS: Between Oct 9, 2014, and Nov 8, 2015, we enrolled 354 stillbirths (born to 350 women). Among the women with available data, 133 (38%) of 350 had hypertension, median age was 27 years (IQR 23-33), 51 (18%) of 291 were obese, six (2%) of 344 had syphilis, and 94 (27%) of 350 had HIV. 63 (18%) of 341 fetuses showed intrauterine growth restriction. Of 298 cases (born to 294 mothers) with complete samples, the most common causes of stillbirth were maternal medical conditions (64 [21%] cases; among them 56 [19%] with hypertensive disorders and six [2%] with diabetes), placental or fetal infections (58 [19%]; 47 [16%] with fetal invasive bacterial infection), pathological placental conditions (57 [19%]; among them 27 [9%] with fetal membrane and placental inflammation and 26 [9%] with circulatory abnormalities), and clinical obstetric complications (54 [18%]; 45 [15%] with placental abruption). Six (2%) stillbirths were attributed to fetal, genetic, or structural abnormalities. In 55 (18%) cases, no cause of death was identified. The most common bacteria to which stillbirths due to fetal invasive infections were attributed were group B streptococcus (15 [5%] cases), E coli (12 [4%]), E faecalis (six [2%]), and S aureus (five [2%]). INTERPRETATION: Targeted investigation of stillbirths (even without fetal autopsy) can ascertain a cause of stillbirth in most cases. Further studies using such investigations are needed to inform the prioritisation of interventions to reduce stillbirths globally. FUNDING: Novartis and GlaxoSmithKline.


Assuntos
Causas de Morte , Complicações Infecciosas na Gravidez , Natimorto/epidemiologia , Adulto , Autopsia , Feminino , Humanos , Hipertensão/mortalidade , Doenças Placentárias/mortalidade , Gravidez , Complicações Infecciosas na Gravidez/mortalidade , Cuidado Pré-Natal , Estudos Prospectivos , África do Sul
11.
Anat Rec (Hoboken) ; 299(11): 1548-1560, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27532288

RESUMO

This study uses Ki-67 and doublecortin (DCX) immunohistochemistry to delineate potential neurogenic zones, migratory pathways, and terminal fields associated with adult neurogenesis in the brains of three microchiropterans. As with most mammals studied to date, the canonical subgranular and subventricular neurogenic zones were observed. Distinct labeling of newly born cells and immature neurons within the dentate gyrus of the hippocampus was observed in all species. A distinct rostral migratory stream (RMS) that appears to split around the medial aspect of the caudate nucleus was observed. These two rostral stream divisions appear to merge at the rostroventral corner of the caudate nucleus to turn and enter the olfactory bulb, where a large terminal field of immature neurons was observed. DCX immunolabeled neurons were observed mostly in the rostral neocortex, but a potential migratory stream to the neocortex was not identified. A broad swathe of newly born cells and immature neurons was found between the caudoventral division of the RMS and the piriform cortex. In addition, occasional immature neurons were observed in the amygdala and DCX-immunopositive axons were observed in the anterior commissure. While the majority of these features have been found in several mammal species, the large number of DCX immunolabeled cells found between the RMS and the piriform cortex and the presence of DCX immunostained axons in the anterior commissure are features only observed in microchiropterans and insectivores to date. In the diphyletic scenario of chiropteran evolution, these observations align the microchiropterans with the insectivores. Anat Rec, 299:1548-1560, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Encéfalo/metabolismo , Antígeno Ki-67/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Animais , Quirópteros , Proteínas do Domínio Duplacortina , Imuno-Histoquímica , Células-Tronco Neurais/metabolismo , Neurogênese/fisiologia
12.
Brain Struct Funct ; 220(1): 361-83, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24178679

RESUMO

The hippocampus is essential for the formation and retrieval of memories and is a crucial neural structure sub-serving complex cognition. Adult hippocampal neurogenesis, the birth, migration and integration of new neurons, is thought to contribute to hippocampal circuit plasticity to augment function. We evaluated hippocampal volume in relation to brain volume in 375 mammal species and examined 71 mammal species for the presence of adult hippocampal neurogenesis using immunohistochemistry for doublecortin, an endogenous marker of immature neurons that can be used as a proxy marker for the presence of adult neurogenesis. We identified that the hippocampus in cetaceans (whales, dolphins and porpoises) is both absolutely and relatively small for their overall brain size, and found that the mammalian hippocampus scaled as an exponential function in relation to brain volume. In contrast, the amygdala was found to scale as a linear function of brain volume, but again, the relative size of the amygdala in cetaceans was small. The cetacean hippocampus lacks staining for doublecortin in the dentate gyrus and thus shows no clear signs of adult hippocampal neurogenesis. This lack of evidence of adult hippocampal neurogenesis, along with the small hippocampus, questions current assumptions regarding cognitive abilities associated with hippocampal function in the cetaceans. These anatomical features of the cetacean hippocampus may be related to the lack of postnatal sleep, causing a postnatal cessation of hippocampal neurogenesis.


Assuntos
Hipocampo/citologia , Hipocampo/fisiologia , Mamíferos/anatomia & histologia , Neurogênese/fisiologia , Neurônios/fisiologia , Animais , Cetáceos/anatomia & histologia , Proteínas do Domínio Duplacortina , Modelos Lineares , Proteínas Associadas aos Microtúbulos/metabolismo , Neuropeptídeos/metabolismo , Especificidade da Espécie
13.
Brain Behav Evol ; 84(3): 227-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25377859

RESUMO

Adult neurogenesis in the mammalian brain is now a widely accepted phenomenon, typically occurring in two forebrain structures: the subgranular zone (SGZ) of the hippocampal dentate gyrus and the subventricular zone (SVZ). Until recently, the majority of studies have focused on laboratory rodents, and it is under debate whether the process of adult neurogenesis occurs outside of the SGZ and the SVZ in other mammalian species. In the present study, we investigated potential adult neurogenetic sites in the brains of two elephant shrews/sengis, a golden mole and a rock hyrax, all members of the superorder Afrotheria. Doublecortin (DCX) immunoreactivity was used as a proxy to visualise adult neurogenesis, which is expressed in neuronal precursor cells and immature neurons. In all four species, densely packed DCX-positive cells were present in the SVZ, from where cells appear to migrate along the rostral migratory stream towards the olfactory bulb (OB). DCX-immunopositive cells were present in the granular cell layer and the glomerular layer of the OB. In the hippocampus, DCX-immunopositive cells were observed in the SGZ and in the granular layer of the dentate gyrus, with DCX-immunopositive processes extending into the molecular layer. In addition to these well-established adult neurogenic regions, DCX-immunopositive cells were also observed in layer II of the neocortex and the piriform cortex. While the present study reveals a similar pattern of adult neurogenesis to that reported previously in other mammals, further studies are needed to clarify if the cortical DCX-immunopositive cells are newly generated neurons or cells undergoing cortical remodelling.


Assuntos
Encéfalo/citologia , Encéfalo/fisiologia , Neurogênese , Neurônios/citologia , Animais , Proteínas do Domínio Duplacortina , Hipocampo/citologia , Imuno-Histoquímica , Ventrículos Laterais/citologia , Proteínas Associadas aos Microtúbulos/análise , Toupeiras/anatomia & histologia , Neuropeptídeos/análise , Musaranhos/anatomia & histologia
14.
Anat Rec (Hoboken) ; 296(10): 1489-500, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23832836

RESUMO

It is a central assumption that larger bodies require larger brains, across species but also possibly within species with continuous growth throughout the lifetime, such as the crocodile. The current study investigates the relationships between body growth (length and mass) and the rates of growth of various subdivisions of the central nervous system (CNS) (brain, spinal cord, eyes) in Nile crocodiles weighing between 90 g and 90 kg. Although the brain appears to grow in two phases in relation to body mass, initially very rapidly then very slowly, it turns out that brain mass increases continuously as a power function of body mass with a small exponent of 0.256, such that a 10-fold increase in body mass is accompanied by a 1.8-fold in brain mass. Eye volume increases slowly with increasing body mass, as a power function of the latter with an exponent of 0.37. The spinal cord, however, grows more rapidly in mass, accompanying body mass raised to an exponent of 0.54, and increasing in length as predicted, with body mass raised to an exponent of 0.32 (close to the predicted 1/3). While supporting the expectation formulated by Jerison that larger bodies require larger brains to operate them, our findings show that: (1) the rate of increase in brain size is very small compared to body growth; and (2) different parts of the CNS grow at different rates accompanying continuous body growth, with a faster increase in spinal cord mass and eye volume, than in brain mass.


Assuntos
Jacarés e Crocodilos/crescimento & desenvolvimento , Encéfalo/crescimento & desenvolvimento , Olho/crescimento & desenvolvimento , Medula Espinal/crescimento & desenvolvimento , Jacarés e Crocodilos/anatomia & histologia , Jacarés e Crocodilos/metabolismo , Animais , Índice de Massa Corporal , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Olho/anatomia & histologia , Olho/metabolismo , Feminino , Masculino , Medula Espinal/anatomia & histologia , Medula Espinal/metabolismo
15.
Afr J AIDS Res ; 10 Suppl 1: 369-80, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-25865513

RESUMO

Like many other developing nations, South Africa faces the challenge of mobilising resources in response to the HIV pandemic. There is a large budget gap between the ideal and the actual amount of funding needed to achieve universal access to highly active antiretroviral therapy (HAART). In addition to financial demands, new burdens are being placed on HAART programmes with the emergence of HIV drug resistance (HIVDR). Thus, a major threat to successful HAART rollout is HIVDR due to non-adherence to HAART. The use of HAART as a primary and secondary HIV-prevention strategy could be ineffective in situations characterised by high rates of non-adherence. In this context, the research looked at issues related to adherence and non-adherence to HAART from the perspective of the provider. Using the software TreeAge Pro 2009, we developed a Markov model to project economic outcomes for a hypothetical cohort of HIV/AIDS patients on HAART. The model compared two scenarios: adherence and non-adherence to HAART. Input data for the model was obtained from existing literature on HAART uptake in South Africa. Moral arguments were analysed and managed through moral reasoning and critical thinking. Discounted lifetime costs for adherent and non-adherent HAART patients in South Africa were estimated at US$9 771 and US$14 762, respectively. The model showed the loss of 4.55 quality-adjusted life years (QALYs) for non-adherent patients, which could be otherwise gained through improved adherence. The incremental cost-effectiveness ratio (ICER) indicated that restricting HAART access only to adherent patients was the dominant strategy. We suggest that, although not a panacea, the withholding or withdrawal of treatment from non-adherent individuals as a precautionary intervention has economic and moral merit.

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