Association of Red Meat Intake and Colorectal Cancer among East-Asians: A Systematic Review and Meta-analysis of Observational Studies Performed between 2011-2021

BACKGROUND AND AIMS

Colorectal cancer has the third highest incidence and second highest mortality among all cancers worldwide. Although numerous studies investigating the associations between high red meat intake and risk of colorectal cancer have been published, the association between the intake of red meat and the risk of colorectal cancer in Asians remains unclear. We performed a systematic review and meta-analysis of cohort and case-control studies to estimate the association between red meat intake and colorectal cancer incidence rate between 2011-2021.

METHOD

We searched PubMed database from 1 Jan 2011 to 21 July 2021. Prospective cohort studies and nested case-control studies that reported results on the association between red meat consumption and colorectal cancer were included in the meta-analysis. The outcome of interest was the association between the intake of red meat and the risk of colorectal cancer. We performed a meta-analysis to calculate the odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

A total of 5 studies enrolling 48,158 participants were included. The results showed no significant association between red meat intake and colorectal cancer risks (OR=1.38; 95%CI: 0.98-1.93). The aspect of the corresponding funnel plot suggested the presence of significant publication bias. Egger's test confirmed the significant asymmetry of the funnel plot (t = 9.3024, p = 0.0026).

CONCLUSIONS

Contrary to many other meta-analyses, our study showed that intake of red meat was not associated with increased risk of colorectal cancer in East-Asians from China, Japan and South Korea. However, due to the limited number of included papers and the lack of confounders adjustments, our results warrant cautious interpretations.

Nitric oxide synthase neurons in different areas of normal aged and Alzheimer's brains

This study investigated the distribution of nitric oxide synthase-containing neurons in the cerebral cortex of individuals with Alzheimer's disease, and compared them with age-matched controls. Paraffin-embedded sections of the frontal (area 10), occipital (area 17) and entorhinal cortices (area 28), and hippocampal formation obtained from 13 autopsy cases were used in the study. Neurons expressing nitric oxide synthase messenger RNA and protein were identified, respectively, by in situ hybridization and immunohistochemistry. Optical densities of nitric oxide synthase-positive neurons were assessed in 50 randomly selected fields of each of the above regions of the cortices, in each case by microscopic photometry. In the frontal cortex of the Alzheimer group, while a decrease in the number of nitric oxide synthase-positive neurons was evident, the nitric oxide synthase neurons, on the other hand, showed an increased optical density in layers II-IV when compared with those of normal ageing. In the occipital cortices, no significant differences in optical density were recorded between the normal ageing and Alzheimer specimens. In the entorhinal cortex, the optical densities of nitric oxide synthase neurons were again similar between the Alzheimer and age-matched control groups. In the hippocampar formation itself, there was an increase of nitric oxide synthase staining in the Alzheimer patients. These results show that (i) nitric oxide synthase neurons are abundant in the human cortex, (ii) the distribution of nitric oxide synthase neurons differs between different cortical regions, and (iii) there are differences between normal ageing and Alzheimer patients in the frontal cortex and the hippocampus.

Reactive hemophagocytic syndrome in childhood--frequent occurrence of atypical mononuclear cells

Reactive hemophagocytic syndrome, which is characterized by systemic proliferation of benign hemophagocytic histiocytes, usually presents as an acute febrile illness with pancytopenia and hepatosplenomegaly. The commoner diseases associated with the syndrome are infection and malignant lymphoma. In this report, eight cases of reactive hemophagocytic syndrome occurring in infants and young children are described. Unlike the disease occurring in adults, there is frequent occurrence of atypical mononuclear cells both in the peripheral blood and bone marrow. The morphological spectrum of these atypical cells is however still within that seen in infectious mononucleosis, and their reactive nature is substantiated by their spontaneous disappearance and subsequent recovery of the patients. It is important to distinguish this reactive proliferation from the neoplastic cells of 'malignant histiocytosis' or malignant lymphoma, since cytotoxic drugs are not warranted for treatment of this non-neoplastic condition.

Evaluation of a low-cost automatic counting system for nuclear track detectors

This paper describes a low-cost automatic counting system for recognising and counting microscopic track holes in plastic nuclear track detectors. The hardware includes an Olympus BH2 microscope, (manufactured by the Olympus Optical Company, Japan) a Philips resistive gate sensor (RGS) board, (manufactured by the Philips Company, Netherlands) a frame-grabber board and an IBM PC compatible. The RGS board acts like a camera, sending analog video signals of the microscope's field image to the frame-grabber, which produces a digital image with a resolution of 256 x 256 pixels and 128 grey levels in about 20 ms. This is then stored in either one of two 64K on-board RAMs for processing by the PC. The software is menu-driven and allows image grabbing, saving, loading and processing. The image processing can be divided into three parts namely: segmentation, speckle elimination and the removal of ill-formed track holes. In this paper we will present the results of testing the system with sample images obtained from CR-39 plastic nuclear track detectors. The limitations of the system for counting track holes on these detectors will be discussed.

Effect of endothelin-1 on the vascular smooth muscle cell cycle

Rabbit vascular smooth muscle cells were cultured in various concentrations of endothelin-1 (ET-1) at 37 degrees C for 24 h. The vascular smooth muscle cell cycle distribution was determined by flow cytometry according to DNA content. In the control group, the mitotically active phase (S + G2 + M phase) of vascular smooth muscle cells was 11.94%. In ET-1-cultured smooth muscle cells, the mitotically active phase was 11.69% at a concentration of 1 pM ET-1, whereas the mitotically active phases were 18.98 and 26.91% at concentrations of 0.1 and 10 nM ET-1, respectively. The findings show that ET-1 significantly increased mitotic activity of cultured vascular smooth muscle cells.

Four documented cases of eosinophilic meningoencephalitis due to Angiostrongylus cantonensis in Hong Kong

4 cases of eosinophilic meningoencephalitis in Hong Kong are described. The major clinical features of the patients, who were 2-60 years old, were low grade fever, headache, mild meningeal signs, right facial palsy or hemiplegia. Eosinophilia in the peripheral blood and eosinophilic pleocytosis were prominent. Computerized tomography scans of brain showed a small area of attenuation with surrounding hypodense area; the lesion was resolved 1-2 months after admission to hospital. Electroencephalograms revealed abnormally slow dysrhythmia. Sections of a nematode observed in the brain of a patient who died were identified as those of young adult Angiostrongylus cantonensis. High ELISA titres against the crude antigens of this nematode were also noted in the serum of 3 patients. The disease is probably under-recognized in Hong Kong.

Ristocetin-induced platelet agglutination in four Chinese patients with Glanzmann's thrombasthenia

We studied the degree of Ristocetin-induced platelet agglutination in 4 Chinese patients with Glanzmann's thrombasthenia. At Ristocetin concentrations of 1.2-2.0 mg/ml (final concentration) variable, abnormal responses were observed. The most notable feature in 3 of 4 patients studied was the phenomenon of dose dependent, cyclic platelet agglutination-disagglutination. However, this phenomenon could be reproduced in only one of the 2 patients who were investigated on 2 separate occasions. Variable, but often characteristic responses of thrombasthenic platelets to different concentrations of Ristocetin are a useful additional diagnostic marker for this disease.

Simultaneous glottic and supraglottic laryngeal webs: report of a case

In a rare case of simultaneous glottic and supraglottic webbing a tantalum keel, as described by McNaught, and a silcone elastomer keel, as described by Montgomery, were placed simultaneously via laryngofissure. Use of different materials appeared to have no bearing on the final, successful outcome.