Histological pattern of laryngeal cancers in Komfo Anokye Teaching Hospital

Carcinoma of the larynx is one of the commonest malignant tumours of the upper respiratory system.The main objective of this study was to highlight the histological pattern and evaluate the occurrence of the  malignant tumours of the larynx. This was a retrospective study involving 146 patients aged between 36 to 77 years with an average age of 59.7 years. Patients with symptoms and signs of laryngeal tumour were studied at the Komfo Anokye Teaching Hospital, Kumasi for a 10 year period from 2003 to 2012. Biopsies of suspected cases were taken and sent to the Histopathology Laboratory for histological analysis. The study revealed that there was a high occurrence of squamous cell carcinoma resulting in 92.0% of the patients. This was followed by verrucous carcinoma in 3.4% of the patients, adenocarcinoma and adenoid cystic carcinoma in 1.7% of the patients. Lastly, there was neuroendocrine carcinoma in only one patient (0.9%). This study confirmed histologically that the squamous cell  carcinoma was the most frequently manifested tumour of the larynx.Keywords: Larynx, Cancers, Histology, Carcinoma

The modern pollen-vegetation relationship of a tropical forest-savannah mosaic landscape, Ghana, West Africa

Transitions between forest and savannah vegetation types in fossil pollen records are often poorly understood due to over-production by taxa such as Poaceae and a lack of modern pollen-vegetation studies. Here, modern pollen assemblages from within a forest-savannah transition in West Africa are presented and compared, their characteristic taxa discussed, and implications for the fossil record considered. Fifteen artificial pollen traps were deployed for 1 year, to collect pollen rain from three vegetation plots within the forest-savannah transition in Ghana. High percentages of Poaceae and Melastomataceae/Combretaceae were recorded in all three plots. Erythrophleum suaveolens characterised the forest plot, Manilkara obovata the transition plot and Terminalia the savannah plot. The results indicate that Poaceae pollen influx rates provide the best representation of the forest-savannah gradient, and that a Poaceae abundance of >40% should be considered as indicative of savannah-type vegetation in the fossil record

Expression of immunohistochemical markers in non-oropharyngeal head and neck squamous cell carcinoma in Ghana.

BACKGROUND:Head and neck cancers include carcinomas of the oral cavity, larynx, sinonasal tract and nasopharynx. Studies on molecular expression of prognostic tumour markers in Ghana are scarce. The purpose of this study was to determine the expression of p53, p16, EGFR, Cyclin-D1 and HER2 among patients with non-oropharyngeal head and neck squamous cell carcinoma (HNSCC). METHODOLOGY:Tissue microarrays from 154 histologically confirmed non-oropharyngeal HNSCC at the Komfo Anokye Teaching Hospital from 2006-2014 were constructed using duplicate cores of representative and viable areas from tumours. Expression of EGFR, p53, p16, Cyclin-D1 and HER2 was evaluated using immunohistochemistry. RESULTS:For non-oropharyngeal HNSCC, majority of the cases (66.2%; 102/154) had stage IV disease. EGFR was the most expressed molecular marker (29.4%; 25/85) followed by p53 (24.0%; 29/121), p16 (18.3%; 23/126) and Cyclin-D1 (10.0%; 12/120). HER2 was not expressed in any of the cases. There was a significantly (p = 0.022) higher expression of Cyclin-D1 in tumours of the oral cavity (19.6%; 9/46) than in those of the larynx (4.7%; 2/43) and nose (3.2%; 1/31). Tumours in stages I-III were more frequently positive for p16 (28.6%; 12/42) than tumours in stage IV (13.1%; 11/84). CONCLUSION:Expression of p53, EGFR, p16 and Cyclin-D1 in non-oropharyngeal HNSCC in Ghana is largely similar to what has been reported in published studies from other countries

Correction: Expression of immunohistochemical markers in non-oropharyngeal head and neck squamous cell carcinoma in Ghana.

[This corrects the article DOI: 10.1371/journal.pone.0202790.]

Contrasting carbon cycle along tropical forest aridity gradients in West Africa and Amazonia

International audienceTropical forests cover large areas of equatorial Africa and play a substantial role in the global carbon cycle. However, there has been a lack of biometric measurements to understand the forests’ gross and net primary productivity (GPP, NPP) and their allocation. Here we present a detailed field assessment of the carbon budget of multiple forest sites in Africa, by monitoring 14 one-hectare plots along an aridity gradient in Ghana, West Africa. When compared with an equivalent aridity gradient in Amazonia, the studied West African forests generally had higher productivity and lower carbon use efficiency (CUE). The West African aridity gradient consistently shows the highest NPP, CUE, GPP, and autotrophic respiration at a medium-aridity site, Bobiri. Notably, NPP and GPP of the site are the highest yet reported anywhere for intact forests. Widely used data products substantially underestimate productivity when compared to biometric measurements in Amazonia and Africa. Our analysis suggests that the high productivity of the African forests is linked to their large GPP allocation to canopy and semi-deciduous characteristics