Volumetric MRI demonstrates atrophy of the olfactory cortex in AD

OBJECTIVE

Alzheimer disease (AD) is a chronic neurodegenerative disorder that affects millions of individuals worldwide. Symptoms include memory dysfunction and deficits in attention, planning, language, and overall cognitive function. Olfactory dysfunction is a common symptom of AD and evidence supports that it is an early marker. Furthermore, olfactory bulb and entorhinal cortex atrophy are well described in AD. However, in AD, no studies have assessed the olfactory cortex as a whole and if sex effects are observed.

METHODS

Magnetic Resonance Imaging was used to scan 39 participants with an average age of 72 years and included men and women. AAL Single-Subject Atlas (implemented in PNEURO tool - PMOD 3.8) was used to determine the volume of the olfactory cortex and the hippocampus. Olfactory cortex volume was lower in both men and women AD cases compared with controls. This decrease was more apparent in the left olfactory cortex and was influenced by age. As expected, hippocampal volume was also significantly reduced in AD. However, this was only observed in the male cohort. A significant correlation was observed between levels of education and hippocampal volume in controls that were not detected in the AD participants. Asymmetry was observed in the olfactory cortex volume when comparing left and right volumes in both the control and AD participants, which was not observed in the hippocampus.

RESULTS

These data highlight the importance of the role of olfactory cortical atrophy in the pathogenesis of AD and the interplay between the olfactory deficits and degeneration of olfactory regions in the brain.

Subgingival plaque microbiota in Saudi Arabians after use of miswak chewing stick and toothbrush

BACKGROUND

The chewing stick, the miswak, is used in many developing countries as the traditional means for oral hygiene. It is prepared from the roots, twigs and stem of Salvadora persica or other alternative local plants.

OBJECTIVES

To compare the effects of the chewing stick miswak (from S. persica) and toothbrush on subgingival plaque microflora among Saudi Arabian individuals. Further, to investigate whether components extracted from S. persica may interfere with the subgingival plaque micro-organisms.

MATERIAL AND METHODS

Fifteen healthy Saudi Arabian male volunteers aged 21-36 years were included in a single-blind, randomized cross-over study. The participants were taught how to use each device properly. Plaque sampling for DNA test was performed at the baseline, 1 week after professional tooth cleaning, and after 3 weeks of either miswak or toothbrush use. Identification and quantification of microbial species were performed by the checkerboard method, using whole genomic, digoxigenin-labelled DNA probes. Inhibition zones around miswak were examined on agar plates with Actinobacillus actinomycetemcomitans and the leukotoxicity of this bacterium was analyzed in a bioassay with macrophages+/-extracts of miswak.

RESULTS

Miswak and toothbrushing had a similar influence on the levels of the subgingival microbiota. However, A. actinomycetemcomitans was significantly more reduced by miswak (p<0.05) than by toothbrushing. These results were supported by our in vitro results which, indicated that extracts from S. persica might interfere with the growth and leukotoxicity of A. actinomycetemcomitans.

CONCLUSIONS

In contrast to toothbrush use, miswak use significantly reduced the amount of A. actinomycetemcomitans in the subgingival plaque.

Duodenal and ampullary obstruction by a Peutz-Jeghers polyp

We report a case of Peutz-Jeghers syndrome presenting with obstruction of the second part of the duodenum and the ampulla of Vater by a large intra-luminal polyp leading to duodenal obstruction and obstructive jaundice. CT scan of the abdomen showed a large polypoidal lesion, a caecal polyp and jejuno-jejunal intussusception. At surgery, two intussusceptions were reduced and leading polyps were excised via two enterotomies; the caecal polyp was excised via caecotomy. The duodenal polyp was excised by limited duodenectomy after frozen section has shown no evidence of malignancy. Histopathological study of all the excised polyps including that of the duodenum showed hamartomatous polyps with no malignant changes. Apart from acute bleeding, this case highlights many of the surgical gastrointestinal complications of Peutz-Jeghers syndrome. It also highlights the unusual combined duodenal and common bile duct obstruction by a large Peutz-Jeghers polyp. The controversial association of this syndrome with cancer and management options is also discussed.

Treatment of chronic hepatitis C genotype IV with interferon-ribavirin combination in Saudi Arabia: a multicentre study

Between 1996 and 1997, we conducted a multicentre study to assess the effect of combination therapy of interferon (IFN) + ribavirin on chronic hepatitis C genotype 4. Ninety-seven patients were enrolled. Sixty-eight patients (47 male and 21 female) were non-responders to previous therapy with IFN (Group I). Twenty-nine patients (19 male and 10 female) were new (Group II). Following treatment with IFN, 23% in Group I and 9% in Group II had a sustained biochemical response. Only 12% in Group I and 5% in Group II achieved a sustained virological response. Virus load was found to be the major factor determining response, followed by histology grading and staging. Like HCV genotype 1, HCV genotype 4 seems to have a poor response to therapy.