PHARMACOGNISTIC, ACUTE TOXICITY AND ANALGESIC STUDIES OF THE STEM OF GUIERA SENEGALENSIS J.F GMIEL (COMBRETACCEAE)

The various features of the whole stem of Guiera senegalensis J.F. Gmiel were observed macroscopically and microscopically using standard description of terms. Macroscopically, it presents an ash grey stem with numerous knots that send out fibrous/pubescent bark branches with a characteristic odour and a slightly bitter taste. The length of the stem ranges from 1 to 3m and 5 to 10mm in diameter. Microscopically, the powdered stem revealed lignified fibres, prism calcium oxalate crystals, modullary rays on the fibres, parenchyma cells and cork cells. The tranverse section of the stem shows cork cells of thin paranchymatous cells arranged in rows, thick walled and lignified sclereids, sieve tubes, medullary rays. The moisture content of the crude drug was found to be 6.75% w/w. the total ash value, water soluble ash value and acid insoluble ash value were 1.92% w/w, 0.88% w/w, and 1.23% w/w respectively. The percentage of alcohol extractive value was found to be 0.94% w/w and the water extractive value was found to be 0.53% w/w. In the mice writhing assay, the extract was found to inhibit the acetic acid induced writhing in mice in dose dependant manner. The acute toxicity study did not result in any observable symptoms or in death. No toxic effects were observed throughout the 7-day study period. No mouse showed signs of toxic effect such as changes on skin, fur, eyes, mucus membrane and behavioral patterns. There were no tremors, salivation, diarrhea, sleep/coma or death of any mouse

Penetrating abdominal injuries in children: a study of 33 cases

Background: Trauma is gradually becoming a major cause of disability and it can be of any form, physical or emotional. For the surgeon the physical form is of major interest, especially its causes and incidence, which can be influenced by environmental or social factors.Aim: The aim of this work was to study the incidence, etiology, principles of management and outcome of children with penetrating abdominal injuries.Materials and methods: This was a 2-year prospective study of 33 children aged 0–15 years with penetrating abdominal injuries at the University of Maiduguri Teaching Hospital in northeast Nigeria. Information obtained included the following: the patient’s biodata, mechanism of injury, time of presentation to the Accident and Emergency Department after the injury, haemodynamic status at presentation, presence or absence of abdominal organ evisceration, presence or absence of associated injuries, the timing of surgery, intraoperative findings, the type of surgical procedure and outcome.Results: Thirty-three (31.4%) children [of whom 24 (i.e. 72.7%) were from the rural areas] of 105 children with trauma-related injuries had penetrating abdominal injuries. The male : female ratio was 3 : 1, and the mean age ± SD was 2.30± 0.81 years. There were 15 (45.4%) children with gunshot wounds, 11 (33.3%) with bomb blast wounds, three (9.1%) with impalement injuries and two (6.1%) with arrow injuries. Fourteen (42.4%) patients had abdominal organ evisceration; of them, nine were as a result of gunshot injuries. Routine exploratory laparotomy was carried out in all 33 patients. Seven (21.2%) were operated on with simultaneous resuscitation in the immediate laparotomy group, and 26 (78.8%) underwent delayed laparotomy. There was a negative laparotomy in four (12.1%) patients, two of whom had only omental evisceration with no other accompanying visceral injuries, and two without evisceration. Three (9.1%) patients died after developing enterocutaneous fistula, compartment syndrome and sepsis.Conclusion: There were more cases of penetrating abdominal injuries among boys and children from the rural areas than in those from urban areas.Keywords: evisceration, exploratory laparotomy, penetrating abdominal injur

Fasting increases susceptibility to acute myocardial ischaemia/reperfusion injury through a sirtuin-3 mediated increase in fatty acid oxidation.

Fasting increases susceptibility to acute myocardial ischaemia/reperfusion injury (IRI) but the mechanisms are unknown. Here, we investigate the role of the mitochondrial NAD+-dependent deacetylase, Sirtuin-3 (SIRT3), which has been shown to influence fatty acid oxidation and cardiac outcomes, as a potential mediator of this effect. Fasting was shown to shift metabolism from glucose towards fatty acid oxidation. This change in metabolic fuel substrate utilisation increased myocardial infarct size in wild-type (WT), but not SIRT3 heterozygous knock-out (KO) mice. Further analysis revealed SIRT3 KO mice were better adapted to starvation through an improved cardiac efficiency, thus protecting them from acute myocardial IRI. Mitochondria from SIRT3 KO mice were hyperacetylated compared to WT mice which may regulate key metabolic processes controlling glucose and fatty acid utilisation in the heart. Fasting and the associated metabolic switch to fatty acid respiration worsens outcomes in WT hearts, whilst hearts from SIRT3 KO mice are better adapted to oxidising fatty acids, thereby protecting them from acute myocardial IRI

Intermittent left cervical vagal nerve stimulation damages the stellate ganglia and reduces the ventricular rate during sustained atrial fibrillation in ambulatory dogs

BACKGROUND: The effects of intermittent open-loop vagal nerve stimulation (VNS) on the ventricular rate (VR) during atrial fibrillation (AF) remain unclear. OBJECTIVE: The purpose of this study was to test the hypothesis that VNS damages the stellate ganglion (SG) and improves VR control during persistent AF. METHODS: We performed left cervical VNS in ambulatory dogs while recording the left SG nerve activity (SGNA) and vagal nerve activity. Tyrosine hydroxylase (TH) staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess neuronal cell death in the SG. RESULTS: We induced persistent AF by atrial pacing in 6 dogs, followed by intermittent VNS with short ON-time (14 seconds) and long OFF-time (66 seconds). The integrated SGNA and VR during AF were 4.84 mV·s (95% confidence interval [CI] 3.08-6.60 mV·s) and 142 beats/min (95% CI 116-168 beats/min), respectively. During AF, VNS reduced the integrated SGNA and VR, respectively, to 3.74 mV·s (95% CI 2.27-5.20 mV·s; P = .021) and 115 beats/min (95% CI 96-134 beats/min; P = .016) during 66-second OFF-time and to 4.07 mV·s (95% CI 2.42-5.72 mV·s; P = .037) and 114 beats/min (95% CI 83-146 beats/min; P = .039) during 3-minute OFF-time. VNS increased the frequencies of prolonged (>3 seconds) pauses during AF. TH staining showed large confluent areas of damage in the left SG, characterized by pyknotic nuclei, reduced TH staining, increased percentage of TH-negative ganglion cells, and positive TUNEL staining. Occasional TUNEL-positive ganglion cells were also observed in the right SG. CONCLUSION: VNS damaged the SG, leading to reduced SGNA and better rate control during persistent AF

Severe Exercise and Exercise Training Exert Opposite Effects on Human Neutrophil Apoptosis via Altering the Redox Status

Neutrophil spontaneous apoptosis, a process crucial for immune regulation, is mainly controlled by alterations in reactive oxygen species (ROS) and mitochondria integrity. Exercise has been proposed to be a physiological way to modulate immunity; while acute severe exercise (ASE) usually impedes immunity, chronic moderate exercise (CME) improves it. This study aimed to investigate whether and how ASE and CME oppositely regulate human neutrophil apoptosis. Thirteen sedentary young males underwent an initial ASE and were subsequently divided into exercise and control groups. The exercise group (n = 8) underwent 2 months of CME followed by 2 months of detraining. Additional ASE paradigms were performed at the end of each month. Neutrophils were isolated from blood specimens drawn at rest and immediately after each ASE for assaying neutrophil spontaneous apoptosis (annexin-V binding on the outer surface) along with redox-related parameters and mitochondria-related parameters. Our results showed that i) the initial ASE immediately increased the oxidative stress (cytosolic ROS and glutathione oxidation), and sequentially accelerated the reduction of mitochondrial membrane potential, the surface binding of annexin-V, and the generation of mitochondrial ROS; ii) CME upregulated glutathione level, retarded spontaneous apoptosis and delayed mitochondria deterioration; iii) most effects of CME were unchanged after detraining; and iv) CME blocked ASE effects and this capability remained intact even after detraining. Furthermore, the ASE effects on neutrophil spontaneous apoptosis were mimicked by adding exogenous H2O2, but not by suppressing mitochondrial membrane potential. In conclusion, while ASE induced an oxidative state and resulted in acceleration of human neutrophil apoptosis, CME delayed neutrophil apoptosis by maintaining a reduced state for long periods of time even after detraining

More accurate macro-models of solid oxide fuel cells through electrochemical and microstructural parameter estimation - Part II: Parameter estimation

This paper presents a systematic synergetic approach between experimental measurements, equivalent circuit modelling (described in Part I) and macro-scale modelling theory which has proved to be instrumental for the estimation of microstructural and electrochemical features of a Ni- YSZ|YSZ|Pr2NiO4+δ-GDC solid oxide fuel cell (SOFC). The aforementioned parameters have been used to generate a more accurate CFD macro-model which has been validated against the experimental results (presented in Part III)

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Challenges of Management of Childhood Cervical teratomas in a Developing Country

Background: Cervical teratomas are uncommon tumours in paediatric age groups. These are mostly benign and of favourable outcome when promptly diagnosed and surgically extirpated. The objective of this study is to report our experience with the challenges of management of 5 cases of cervical teratoma. Patients and Methods: This is a retrospective study of all cases of cervical teratoma managed at the University of Maiduguri Teaching Hospital and the Federal Medical Centre Gombe, Gombe ,Nigeria. Results: Five cases, comprising 3 neonates and 2 infants. There were 4 females and 1 male. Four of them had predominantly left sided tumour while 1 was right sided. Four had mild to moderate respiratory compromise, which necessitated emergency operation and all the tumours were completely extirpated. Four of the tumours were benign and 1 malignant. Surgical complications encountered were tracheal perforation, and wound infection in 1 patient, wound haematoma in another, and post-extubation tracheal collapse in one other child which resulted in the only mortality recorded. Conclusion: Cervical site remains a rare site of teratoma occurrence and respiratory compromise is an ever-present danger peri-operatively because of the presenting large cervical masses, anatomical distortions and attenuation of tissues. Postoperative ventilation is advisable for at least 72 hours to forestall preventable mortality. Keywords: Cervical Teratoma, Children, antenatal diagnosis, Nigeria African Journal of Paediatric Surgery Vol. 3 (1) 2006: pp. 9-1