Burn injury: review of pathophysiology and therapeutic modalities in major burns

Despite a considerable decrease in their incidence worldwide, burn injuries remain one of the commonest forms of trauma and account for a weighty proportion of trauma cases in health-care emergencies around the globe. Although the latest data reveal a substantial decline in burn-related mortality and hospital admissions in the US over the past three decades, severe thermal injuries continue to trigger devastating morbidity and significant mortality while their management remains a dynamic challenge for the entire medical and paramedical community. Concrete evidence continues to be established regarding burn-associated pathophysiologic responses, and their destructive sequelae and deleterious effects in survivors at cellular, systemic as well as socio-economic level. Better understanding of these responses have contributed to advances in therapeutic strategies, improved long-term outcomes and catalyzed the reintegration of victims back into society. This paper describes the current understanding of the pathophysiology of a burn injury and characterizes both local and systemic pathophysiologic responses in terms of metabolic, hemodynamics, cardiac, renal, hepatic, gastro-intestinal, immunologic, endocrine as well as male reproductive systems in an attempt to understand the corresponding treatment modalities for this unique patient population.

Bone mineral density and insulin-like growth factor-1 in children with spastic cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) have significant decrease linear growth rate and low bone mineral density (BMD).

AIMS

This study is to evaluate BMD in children with CP and its relation to the levels of insulin-like growth factor-1 (IGF-1).

SUBJECTS AND METHODS

This cross-sectional study was carried out on 58 children suffering from spastic CP with the age range 4-12 years compared to 19 controls. All assessed by dual energy x-ray absorptiometry (DXA) to measure BMD, serum level of IGF-1, and serum vitamin D. The patients were classified according to their GMFCS.

RESULTS

Fractures were reported in seven (12.1%) of cases. Our study demonstrated that, IGF-1 level and BMD decrease in correlation with the severity of CP. IGF-1correlates positively with serum vitamin D, BMI, and BMD. CP children with severe GMFCS level or who use anticonvulsive drugs are at a high risk for low BMD and low levels of IGF-1.

CONCLUSION

Both BMD and IGF-1 were significantly in low children with spastic CP; IGF-1 negatively correlates with the severity of osteopenia in children with spastic. Children with CP who are not independently ambulant or with severe GMFCS level or who use anticonvulsive drugs are at a high risk for developing low BMD.

Prevalence of Hepatitis B surface antigen among biomedical students of African descent in Usmanu Danfodiyo University, Sokoto, Nigeria

BACKGROUND

Hepatitis B (HB) is a serious global public health problem that put health professionals particularly at risk.

OBJECTIVE

The aim of this study was to investigate the prevalence of Hepatitis B surface antigen (HBsAg) among Biomedical Students of African descent attending Usmanu Danfodiyo University Sokoto in North-Western Nigeria.

METHODS

The Onsite HBsAg (CTK Biotech, USA) was used to detect the presence of hepatitis B surface antigen.

RESULTS

We tested 186 consecutively-recruited students consisting of 147 males and 39 females aged 18-35 years (mean age 26 ± 2.0 years). Of the 186 students tested, 25 (13.4%) were positive for HBsAg. The prevalence of HBsAg was significantly higher among students in the 21-25 years age group. Hepatitis B vaccination uptake among students was 7%. Majority of subjects were single 173(93.1%) compared to married 13 (6.9%). Ethnic distribution of the subjects indicated that 104(55.9%) were Hausa compared to Yoruba 32 (17.2%), other ethnic groups 21(11.3%), Fulani 20(10.8%) and Igbo 9(4.8%).

CONCLUSIONS

This study indicates a high prevalence of hepatitis B virus infection among Biomedical students in Sokoto, North Western, Nigeria. Finding from this study is enough justification for the implementation of a policy to routinely test students entering into the biomedical professions for Hepatitis B virus infection. There is the need to provide hepatitis B vaccination universally to all those who are found negative prior to commencement of their biomedical training. There is also need to educate students entering biomedical professions and healthcare workers on the modes of transmission and prevention, importance of being compliant with protective vaccination as well as the need to observe universal precaution and infection control guidelines during their training and future professional practice.

Repeated Acute Oral Exposure to Cannabis sativa Impaired Neurocognitive Behaviours and Cortico-hippocampal Architectonics in Wistar Rats

The most abused illicit drug in both the developing and the developed world is Cannabis disposing users to varying forms of personality disorders. However, the effects of cannabis on cortico-hippocampal architecture and cognitive behaviours still remain elusive.  The present study investigated the neuro-cognitive implications of oral cannabis use in rats. Eighteen adult Wistar rats were randomly grouped to three. Saline was administered to the control rats, cannabis (20 mg/kg) to the experimental group I, while Scopolamine (1 mg/kg. ip) was administered to the last group as a standard measure for the cannabis induced cognitive impairment. All treatments lasted for seven consecutive days. Open Field Test (OFT) was used to assess locomotor activities, Elevated Plus Maze (EPM) for anxiety-like behaviour, and Y maze paradigm for spatial memory and data subjected to ANOVA and T test respectively. Thereafter, rats were sacrificed and brains removed for histopathological studies. Cannabis significantly reduced rearing frequencies in the OFT and EPM, and increased freezing period in the OFT. It also reduced percentage alternation similar to scopolamine in the Y maze, and these effects were coupled with alterations in the cortico-hippocampal neuronal architectures. These results point to the detrimental impacts of cannabis on cortico-hippocampal neuronal architecture and morphology, and consequently cognitive deficits.

Chemical group-dependent plasma polymerisation preferentially directs adipose stem cell differentiation towards osteogenic or chondrogenic lineages

Human adipose derived stem cells (ADSCs) are being explored for the repair of craniofacial defects due to their multi-differentiation potential and ease of isolation and expansion. Crucial to using ADSCs for craniofacial repair is the availability of materials with appropriate biomechanical properties that can support their differentiation into bone and cartilage. We tested the hypothesis that different modifications of chemical groups on the surface of a nanocomposite polymer could increase human ADSC adhesion and selectively enhance their osteogenic and chondrogenic differentiation. We show that the COOH modification significantly promoted initial cell adhesion and proliferation over 14 days compared to NH₂ surfaces. Expression of focal adhesion kinase and vinculin was enhanced after plasma surface polymerisation at 24 h. The COOH modification significantly enhanced chondrogenic differentiation as indicated by up-regulation of aggrecan and collagen II transcripts. In contrast, NH₂ group functionalised scaffolds promoted osteogenic differentiation with significantly enhanced expression of collagen I, alkaline phosphatase and osteocalcin both at the gene and protein level. Finally, chorioallantoic membrane grafting demonstrated that both NH₂ and COOH functionalised scaffolds seeded with ADSCs were biocompatible and supported vessel ingrowth apparently to a greater degree than unmodified scaffolds. In summary, our study shows the ability to direct ADSC chondrogenic and osteogenic differentiation by deposition of different chemical groups through plasma surface polymerisation. Hence this approach could be used to selectively enhance bone or cartilage formation before implantation in vivo to repair skeletal defects.

Statement of Significance

Human adipose derived stem cells (hADSCs) are an exciting stem cell source for regenerative medicine due to their plentiful supply and ease of isolation. However, the optimal environmental cues to direct stem cells towards certain lineages change have to has not been identified. We have shown that by modifying the surface of the scaffold with specific chemical groups using plasma surface polymerisation techniques we can control ADSCs differentiation. This study shows that ADSCs can be differentiated towards osteogenic and chondrogenic lineages on amine (NH₂) and carboxyl (COOH) modified scaffolds respectively. Plasma polymerisation can be easily applied to other biomaterial surfaces to direct stem cell differentiation for the regeneration of bone and cartilage.

Effect of the oxygen affected layer in multilayered photopolymers

Photopolymerization is known to be limited in depth by light absorption.

Nanotechnology for Stimulating Osteoprogenitor Differentiation

Background:

Bone is the second most transplanted tissue and due to its complex structure, metabolic demands and various functions, current reconstructive options such as foreign body implants and autologous tissue transfer are limited in their ability to restore defects. Most tissue engineering approaches target osteoinduction of osteoprogenitor cells by modifying the extracellular environment, using scaffolds or targeting intracellular signaling mechanisms or commonly a combination of all of these. Whilst there is no consensus as to what is the optimal cell type or approach, nanotechnology has been proposed as a powerful tool to manipulate the biomolecular and physical environment to direct osteoprogenitor cells to induce bone formation.

Methods:

Review of the published literature was undertaken to provide an overview of the use of nanotechnology to control osteoprogenitor differentiation and discuss the most recent developments, limitations and future directions.

Results:

Nanotechnology can be used to stimulate osteoprogenitor differentiation in a variety of way. We have principally classified research into nanotechnology for bone tissue engineering as generating biomimetic scaffolds, a vector to deliver genes or growth factors to cells or to alter the biophysical environment. A number of studies have shown promising results with regards to directing ostroprogenitor cell differentiation although limitations include a lack of in vivo data and incomplete characterization of engineered bone.

Conclusion:

There is increasing evidence that nanotechnology can be used to direct the fate of osteoprogenitor and promote bone formation. Further analysis of the functional properties and long term survival in animal models is required to assess the maturity and clinical potential of this.

Spectral and fluorescence lifetime endoscopic system using a double-clad photonic crystal fiber

We present a customized small-core double-clad photonic crystal fiber for spectral and fluorescence lifetime measurements of human samples. In this Letter, the new fiber has been characterized on different fluorophores and samples of human brain tumor; a comparison to a bi-fiber homemade system and a commercial fiber probe was made.