Strategies for Oral Health Research in Africa and the Middle Eastern Region

The highest burden of diseases worldwide is in low- and middle-income countries, but due to lack of capacity and inadequate infrastructure, research output from these countries is unable to address existing and emerging challenges in health care. Oral health research has particularly been hampered by low prioritization, resulting in insufficient development of this sector. There is an urgent need for research correlating oral health to upstream social and environmental determinants and promoting the common risk factor approach for prevention of noncommunicable diseases. Population-wide preventive measures for oral health care are more effective than purely curative approaches, especially for vulnerable groups who have limited access to information and appropriate health care. This article identifies priorities and proposes strategies for researchers, stakeholders, and policy makers for the initiation and sustenance of appropriate oral health care research. The proposed interventions are intended to promote collaboration, capacity building, and health advocacy. Local ownership in multinational research projects in low- and middle-income countries, complemented by skills transfer from high-income countries, is encouraged to ensure that regional health needs are addressed. Emphasis is placed on a shift toward translational research that has a direct impact on oral health care systems.

Global oral health inequalities in incidence and outcomes for oral cancer: causes and solutions

The mouth and oropharynx are among the ten most common sites affected by cancer worldwide, but global incidence varies widely. Five-year survival rates exceed 50% in only the best treatment centers. Causes are predominantly lifestyle-related: Tobacco, areca nut, alcohol, poor diet, viral infections, and pollution are all important etiological factors. Oral cancer is a disease of the poor and dispossessed, and reducing social inequalities requires national policies co-ordinated with wider health and social initiatives - the common risk factor approach: control of the environment; safe water; adequate food; public and professional education about early signs and symptoms; early diagnosis and intervention; evidence-based treatments appropriate to available resources; and thoughtful rehabilitation and palliative care. Reductions in inequalities, both within and between countries, are more likely to accrue from the application of existing knowledge in a whole-of-society approach. Basic research aimed at determining individual predisposition and acquired genetic determinants of carcinogenesis and tumor progression, thus allowing for targeted therapies, should be pursued opportunistically.

Catha edulis(Khat) Induces Cell Death by Apoptosis in Leukemia Cell Lines

Khat is the Celastraceus edulis plant, a flowering evergreen tree or large shrub, which grows in the Horn of Africa and southwestern Arabia. Khat use has been associated with development of oral cancer, but its molecular effects remain controversial. This study describes a novel cytotoxic effect of whole khat extract on three leukemia cell lines. Cells were exposed to khat extract and harvested for analysis by fluorescent and electron microscopy, trypan blue exclusion, as well as immunoblotting to characterize the mode of cell death. In a separate series, cells were pretreated with a panel of caspase inhibitors for possible inhibitory effects. Khat induced a rapid cell death effect in HL-60, Jurkat, and NB4 cells that occurred within 2 h of exposure. The treated cells retained their ability to exclude trypan blue dye, a key feature in the apoptotic process. Exposed cells consistently developed morphological features of manifest apoptosis. Z-VAD, a pan-caspase inhibitor, completely inhibited toxic activity for up to 8 h, with partial inhibition by other caspase-specific agents. Western blot analysis showed specific cleavage of caspase-3 in khat-exposed cells. This study shows that khat induces cell death by apoptosis in a process sensitive to inhibition by caspase inhibitors, suggesting that subcellular interactions could be of particular relevance for the biological effects of khat in the cell death process and possibly carcinogenesis.

Neural tumours of the head and neck

OBJECTIVE

To document the pattern of occurrence of all primary neural tumours arising in the neck and craniofacial region over the period 1982 to 1991.

DESIGN

A retrospective study.

SETTING

Cancer Registry, Nairobi, Kenya.

RESULTS

Out of the 289 cases who were identified to have had whole body neural tumours, 225 (77.8%) had the lesions distributed in the neck and craniofacial area. While 80% of the neoplasms located in this region were retinoblastomas (mainly occurring in the age group 0 to 4 years), other lesion types occurred in small numbers thus: neurofibromas comprised 12.4%, Schwannomas four per cent, neuroblastomas and neuromas each 0.4%; and extracranial gliomas 2.7%. Overall, the male to female ratio was 1:1 and the site distribution revealed that over 90% of the lesions afflicted the upper face.

CONCLUSION

Neural tumours of the neck and craniofacial region appear generally rare in this population as has been shown elsewhere.