Occupational exposure to aluminum and its amyloidogenic link with cognitive functions

As many other metals, aluminum is a widely recognized neurotoxicant and its link with neurodegenerative disorders has been the subject of scientific debate. One proposal focuses on amyloid β deposition (amyloidogenesis) as the key player in triggering neuronal dysfunction the so-called amyloid cascade hypothesis. We undertook this study first to investigate the cognition status of workers exposed to Al dust in an Al factory in Southern Cairo, second, to evaluate serum amyloid precursor protein (APP) and cathepsin D (CD) enzyme activity to study the possible role of Al in amyloidogenesis, and finally to explore the relation between these potential biomarkers and cognitive functions. The study was conducted on 54 exposed workers and 51 matched controls. They were subjected to questionnaire, neurological examination and a cognitive test battery, Addenbrooke's Cognitive Examination - Revised (ACE-R). Serum Al, APP and CD enzyme activity were measured. A significant increase of serum Al was found in the exposed workers with an associated increase in serum APP and decrement in CD activity. The exposed workers displayed poor performance on the ACE-R test. No significant correlation was detected between ACE-R test total score and either APP or CD activity. We concluded that occupational exposure to Al is associated with cognitive impairment. The effect of occupational Al exposure on the serum levels of APP and CD activity may be regarded as a possible mechanism of Al in amyloidogenesis. However, our findings do not support the utility of serum APP and CD activity as screening markers for early or preclinical cognitive impairment.

Matrix metalloproteinase-3, vitamin D receptor gene polymorphisms, and occupational risk factors in lumbar disc degeneration

BACKGROUND

Lumbar disc degeneration (LDD) is a process that begins early in life, contributing to the development of low back pain. LDD is a consequence of a variety of factors, and its etiology remains poorly understood. Objectives to investigate occupational and genetic risk factors inducing lumbar disc degeneration, and to evaluate the possible association of genetic polymorphisms of matrix metalloproteinase 3 (MMP-3) and vitamin D receptor (VDR) with the severity of LDD in an Egyptian population.

SUBJECTS AND METHODS

A case control study involving 84 LDD and 60 controls was carried out. Five types of work related factors were investigated by questionnaire, complete neurological examination for all subjects and MRI for the cases. Polymerase chain reaction and restriction fragment length polymorphism methods were applied to detect polymorphisms in MMP-3 Promoter (-1,171 6A/5A) (rs 731236) and VDR-Apa (rs 35068180).

RESULTS

We found that family history, back injury, smoking, high level of sitting, bending/twisting, physical workload, lifting, whole body vibration, mutant allele 5A of MMP-3 and mutant allele T of VDR were significantly associated with LDD (OR = 2.9, 3.1, 2.1, 11.1, 15.9, 11.7, 8.2, 12.6, 2.5 and 3.1 respectively, p < 0.05). Cases that carry allele 5A and/or allele T were associated with LDD severity.

CONCLUSION

LDD is closely associated in occurrence and severity with occupational, environmental risk factors and susceptibility genes namely MMP-3, and VDR (ApaI). This study throws light on the importance of screening for early detection of susceptible individuals and disease prevention.

Survival effects of cyclooxygenase-2 and 12-lipooxygenase in Egyptian women with operable breast cancer

BACKGROUND

Breast cancer (BC) is the commonest among women in Egypt as well as in many other countries. Cyclo-oxygenase-2 (COX-2) and 12-lipo-oxygenase (12-LOX) are over-expressed in 30-40% of patients and carry a poor prognosis. The objectives of this study were to correlate COX-2 and 12-LOX expression with various clinico-pathologic patients' characteristics and their impact on overall survival (OS) and disease free survival (DFS) in Egyptian women with operable BC.

MATERIALS AND METHODS

This prospective study included 57 consecutive BC cases presenting to the Egyptian National Cancer Institute. Sections from BC and nearby normal tissues were examined for expression of COX-2 and 12-LOX using reverse transcriptase polymerase chain reaction.

RESULTS

The patients' median age was 45 years. Fifty-three percent were premenopausal. Stage II and III disease represented 25 and 75% respectively. Adjuvant chemotherapy, radiotherapy and tamoxifen were used in 90, 75 and 60% respectively. Sixty percent had hormone-receptor positive tumors and 28% over-expressed HER2/neu. Forty-nine and sixty-five percent showed over-expression of COX-2 and 12-LOX respectively. Patients with higher TNM stage or who developed visceral metastases had significantly higher COX-2 expression. For the whole group of patients, the median DFS was 37 months, while the median OS was not reached. OS or DFS did not differ significantly between patients with normal and over-expression of COX-2. DFS but not OS was significantly higher in 12-LOX over-expression compared to normal expression.

CONCLUSION

COX-2 over-expression was associated with poor prognostic criteria in BC, but did not affect DFS or OS. 12-LOX over-expression was associated with better DFS, but not OS.