The effect of low-energy laser irradiation on apoptotic factors following experimentally induced transient cerebral ischemia.

Apoptosis, or programmed cell death, resulting from cerebral ischemia may be related to decreased levels of anti-apoptotic factors, such as serine/threonine kinase (Akt), phosphorylated Akt (pAkt), pBAD, and Bcl-2, and increased levels of pro-apoptotic factors, such as BAD, caspase 9, and caspase 3 activities. In this study, we investigated the effects of low-energy laser (660 nm) irradiation (LLI) on the levels and activity of various anti- and pro-apoptotic factors following ischemia. Transient cerebral ischemia was induced in Sprague-Dawley rats by unilateral occlusion of the middle cerebral artery for 1 h, followed by reperfusion. LLI was then directed on the cerebrum for varying lengths of duration (1, 5, or 10 min at an energy density of 2.64 J/cm², 13.2 J/cm², and 24.6 J/cm², respectively). The expression levels of Akt, pAkt, BAD, pBAD, Bcl-2, caspase 9, and caspase 3 activities were measured 4 days after injury. The levels of Akt, pAkt, Bcl-2, and pBAD were significantly increased following laser irradiation. In addition, LLI significantly decreased caspase 9 and caspase 3 activities caused by ischemia-reperfusion. LLI may protect the brain by upregulating Akt, pAkt, pBAD, and Bcl-2 expression and downregulating caspase 9 and caspase 3 expression following transient cerebral ischemia. This modality is a promising protective therapeutic intervention after strokes or other ischemic events.

The influence of mariculture on mercury distribution in sediments and fish around Hong Kong and adjacent mainland China waters.

To study the influence of mariculture on mercury (Hg) speciation and distribution in sediments and cultured fish around Hong Kong and adjacent mainland China waters, sediment samples were collected from six mariculture sites and the corresponding reference sites, 200-300 m away from the mariculture sites. Mariculture activities increased total mercury, organic matter, carbon, nitrogen and sulfur concentrations in the surface sediments underneath mariculture sites, possibly due to the accumulation of unconsumed fish feed and fish excretion. However, methylmercury (MeHg) concentrations and the ratio of MeHg to THg (% MeHg) in sediments underneath mariculture sites were lower than the corresponding reference sites. The % MeHg in sediments was negatively correlated (r = -0.579, p < 0.05) with organic matter (OM) content among all sites, indicating that OM may have inhibited Hg methylation in surface sediments. Three mariculture fish species were collected from each mariculture site, including red snapper (Lutjanus campechanus), orange-spotted grouper (Epinephelus coioides) and snubnose pompano (Trachinotus blochii). The average MeHg concentration in fish muscle was 75 µg kg⁻¹ (wet weight), and the dietary intake of MeHg through fish consumption for Hong Kong residents was 0.37 µg kg⁻¹ week⁻¹, which was lower than the corresponding WHO limits (500 µg kg⁻¹ and 1.6 µg kg⁻¹ week⁻¹).

Differential protein expression induced by a lipid extract of Perna canaliculus in splenocytes of rats with adjuvant-induced arthritis.

The lipid extract of Perna canaliculus (Lyprinol) has known anti-inflammatory effects. However, the only information on mechanisms is regulation of cytokine secretion. Therefore, we conducted a proteomic study exploring the effects of Lyprinol on protein expression in splenocytes collected from AIA rats. Splenocytes from AIA rats fed with Lyprinol had increased protein expression of malate dehydrogenase (MDH). Lyprinol also decreased the expressions of 5 other proteins: protein-o-mannosyl- transferase 2 (PMT-2), Tdrd 7, telethonin, dynactin 2 and protein disulfide isomerase (PDI or glucose-regulated protein (GRP)). Besides MDH, PMT- 2, titin-cap protein and protein disulfide isomerase (PDI) are known to be related to metabolism. However, it is currently unknown if Lyprinol administration decreases metabolic glucose in the body and alleviates symptoms of inflammation and arthritis. Further experiments are required to correlate levels of citric acid intermediates and glucose to the severity of inflammation and pain in AIA rats fed Lyprinol.

A lipid extract of Perna canaliculus affects the expression of pro-inflammatory cytokines in a rat adjuvant-induced arthritis model.

As published initially in this same journal in 2000, the lipid extract of Perna canaliculus (New Zealand green-lipped mussel; Lyprinol) is known for its anti-inflammatory effects in animal models and in human controlled studies (arthritis; asthma). As a follow-up of its effects on pain in a rat model of adjuvant-induced arthritis (ALA), we studied its effects on the production of cytokines known to be associated with inflammation (IL-6, IL-1alpha TNF-alpha, IFN-gamma). Feeding with Lyprinol was associated with significantly decreased expression levels of TNF-alpha and IFN-gamma when compared to Naproxen (positive control) and, even more when compared with sham and extra-virgin olive oil (negative control). When compared to Naproxen, sham and extra-virgin olive oil, the levels of IL-6 and IL-1alpha were also marginally decreased in rats fed with Lyprinol. This study demonstrates that AIA rats fed with Lyprinol had decreased production ofcytokines associated with inflammation.

Hydrogen peroxide induces a rapid production of nitric oxide in mung bean (Phaseolus aureus).

Nitric oxide (NO) has recently been identified as an important signaling molecule in plant immune response. The present study aims to investigate the signaling pathway that leads to NO production. Using the NO specific fluorescent dye DAF-2DA, we observed rapid production of NO in mung bean leaves after the addition of 10 mM hydrogen peroxide (H(2)O(2)). NO was probably produced by a NOS-like enzyme in plants, as the NO production was inhibited by l-NAME, a NOS inhibitor. The NOS-like activity in the total leaf protein preparation of mung bean (Phaseolus aureus) was elevated 8.3-fold after 10 mM H(2)O(2) treatment, as demonstrated using the chemiluminescence NOS assay. The NOS-like activity was BH(4) dependent: omitting BH(4) in the reaction mixture of NOS assay reduced the NOS activity by 76%. We also found that the H(2)O(2) induced NO production was mediated via calcium ion flux, as it was blocked in the presence of a calcium ion channel blocker, verapamil. Results from the present study identified H(2)O(2) as an upstream signal that leads to NO production in plants. H(2)O(2) and NO, besides acting as two independent signaling molecules in plant immune response, may interrelate to form an oxidative cell death (OCD) cycle.