Uduak Emmanuel Umana

Von Economo neurons: A review of the anatomy and functions

Von Economo neurons (VENs) are large bipolar neurons found in the anterior cingulate, fronto-insular, and dorsolateral prefrontal cortices of great apes and the humans. VENs are defined by their thin, elongated cell body, and long dendrites projecting from the apical and basal ends. These neurons are mostly present in particularly high densities in cetaceans, elephants, and hominoid primates mainly, humans and apes. VENs have been shown to contribute in the specializations of neural circuits in species that share both large brain size and complex social cognition due to their location. This could possibly be due to the adaptation to rapidly relay of socially-relevant information over long distances across the brain. The VENs have been shown to be recently evolved cell type that may be involved in the fast intuitive assessment of complex social situations. As such, they could be the part of the circuitry supporting human social networks. The VENs emerge mainly after birth and increase in number until 4 years of age. The presence of VENs in the fronto-insular cortex has been linked to a possible role in the integration of bodily feelings, emotional regulation, and goal-directed behaviors. Some studies have shown decreased number of VENs in neuropsychiatric diseases, in which social cognition is markedly affected. Some researchers have shown that selective destruction of VENs in the early stages of frontotemporal dementia implies that they are involved in empathy, social awareness, and self-control which are consistent with evidence from functional imaging.

Nutritional evaluation using different anthropometric variables in Nigerian school children

The anthropometric characteristics of 600 apparently healthy children of ages between 5 and 10 years of Gbagyi tribe of Abuja Nigeria, consisting of males (n = 300) with a mean age of 7.10 ΁ 1.98 and females (n = 300) with a mean age of 7.68 ΁ 1.86 were selected for the evaluation of their nutritional status using different anthropometric variables. The anthropometric characteristic of their height, age, weight, mid-upper arm circumference (MUAC), chest circumference and body mass index (BMI) was measured and analysed statistically for any significant difference, and correlation between the parameters studied. The results show some significant differences (P ≤ 0.05) between the anthropometric parameters and a significant correlation (≤0.001) between the height and BMI, and other parameters in males and females. The study derived a linear regression and a multiple linear regression equations for Gbagyi children from which height, age, weight, MUAC, chest circumference and BMI could be predicted if one factor is known. The results from the present study provided an insight into the nutritional status of Nigerian school children of Gbagyi tribe of Abuja using the BMI and MUAC which showed if a child is malnourished, overweight or obese. The results from the present study show that there is a positive correlation between height and age, and other parameters indicating that height could be predicted using age, weight, BMI, chest circumference and MUAC, while BMI and mid upper arm circumference could be a useful tool in the estimation of nutritional status among Nigerian school children of Gbagyi tribe of Abuja.

Effects of vitamin E administration on phostoxin-induced changes in the kidney of adult Wistar rats

Aim: The effect of vitamin E on phostoxin-induced changes in biochemical parameters and the kidney of adult Wistar rats were studied. Materials and Methods: Thirty adult Wistar rats of both sexes were randomly separated into six groups of five rats each. Group 1 was the Control and was given normal saline. Group 2 was exposed to phostoxin for 3 hours per day with vitamin E and Group 3 was exposed to phostoxin for 1΍ hours with vitamin E. Groups 4 and 5 were treated with phostoxin only on exposure time of 1΍ and 3 hours respectively while Group 6 was treated with vitamin E only. The rats were exposed to phostoxin through inhalational method for 7 days and at the end of the exposure period, the rats were sacrificed. The blood and tissues were collected for analysis and were processed for histological studies. Results: The results showed significant changes in body weight of the rats (P < 0.05) while there was a significant increase in weight of the kidneys in Groups 3 and 6 when compared to the Control (P < 0.05). The results of the biochemical parameters Na + , K + , Cl−, urea, creatinine and HCO3 showed a significant difference (P < 0.05) between the control and the experimental groups. The results of histological examination of the kidney showed changes in animals exposed to phostoxin when compared to the Control animals. Conclusion: The changes in the kidney depend on the duration of the exposure time while vitamin E administration has been shown to have some level of protection on phostoxin-induced toxicity on the kidney tissues and biochemical parameters of the adult Wistar rats.

Effect of ethanolic extract of Ocimum gratissimum on sodium nitrite-induced cerebellar cortex toxicity in adult Wistar rats

Introduction: Intoxication of nitrites mainly from food and water constitute a potential hazard with a resultant hypoxia. Aim: The aim was to study the effects of ethanolic leaves extract of Ocimum gratissimum on sodium nitrite (NaNO2)-induced cerebellar toxicity in adult Wistar rats. Materials and Methods: Twenty-four adult Wistar rats weighing 150–250g were divided into six groups of four rats each. Group I was the control and received distilled water, Group II received 54 mg/kg body weight (bwt) of NaNO2, Group III received 750 mg/kg bwt of the extract and 54 mg/kg bwt of NaNO2, Group IV received 375 mg/kg bwt of the extract and 54 g/kg bwt of NaNO2, Group V received 54 mg/kg bwt of NaNO2and 2 ml/kg bwt of olive oil, and Group VI received 2 ml/kg bwt of olive oil. The administration was by oral route and lasted for 21 days, after which the animals were sacrificed and blood collected for analyses, and the tissues were processed for histological studies. Results: The result showed a decrease in the mean bwt of the animals in Groups III and IV, a significant increase in serum levels of malondialdehyde and a decrease in superoxide dismutase, glutathione peroxidase, and catalase in Group II. The result of the hematological analysis showed a significant increase in red blood cells, white blood cells, mean corpuscular volume, and mean corpuscular hemoglobin (P < 0.05). The result of histological studies showed degenerative changes in Group IIwith less degeneration in Group IV. Conclusion: The result showed that O. gratissimum in a controlled manner may be useful in the management of neurodegenerative conditions that involve free radical generation and reduction in brain energy production.

Effects of Mercury Chloride on the Cerebral Cortex of Adult Wistar Rats

Mercury is among the heavy metals that have been reported to cause devastating health problem worldwide. The primary site of action of mercury chloride is the central nervous system. This study investigated the effect of mercury chloride on the cerebral cortex of adult wistar rats. Twenty-four (24) adult wistar rats were used for this study. Following four (4) weeks of acclimatization, the rats were randomly divided into five groups of five animals per group. The animals were allowed free access to food and water throughout the period of experment. Group 1 was the control group and was administered distilled water, while groups 2, 3, 4 and 5 were administer 6.6mg/kg, 13.2mg/kg, 26.3mg/kg and 52.2mg/kg body weight of mercury chloride solution orally respectively for eight (8) days. After the period of mercury chloride administration, the animals were anaesthetized using chloroform and where sacrificed. The brain was fixed in Bouins fluid and the tissue processed and stained with haematoxylin and eocin stains and were studied under the microscope. The photomicrographs reveal distortion and diffusion of cells and a widespread necrosis of the cortical neurons. Keywords : Mercury chloride, Cerebral cortex, Degenerative changes