Administration of MgSO4 failed to improve the neurological recovery after complete global brain ischemia in dogs

The cerebral protective effects of MgSO₄ after complete global brain ischemia were evaluated with EEG, evoked potentials (EP) and the neurological recovery score (NRS) in the dog. Complete global brain ischemia for 15 min was achieved by occluding the ascending aorta and the caval veins. The MgSO₄ group (N=7) were injected with a 10% MgSO₄ solution and the control group (N=7) were administered a normal saline intravenously from the beginning of the resuscitation to 48 h after ischemia. The EEG grades (1=normal, 5=flat) in the control group and the MgSO₄ group were 3.9±0.1 (mean ±SEM) and 3.7±0.3, and the EEG-EP scores (6=normal, 0=serious deterioration) were 2.6±0.4 and 2.7±0.4 4h after ischemia, respectively. The 7-day survival rates for ischemia were equal in both groups (5/7:71%). The NRSs (0=death, 100=normal) in the control group and the MgSO₄ group were 50±3 (n=7) and 43±9 (n=7) on the 3rd day after ischemia, and were 56±5 (n=5) and 42±12 (n=5) on the 7th day. The differences between the two groups were not significant. We conclude that MgSO₄ administered after ischemia has no beneficial effects on the recovery of EEG, EP and the NRS after 15 min of complete global brain ischemia in the dog.     

New cholesterol biosynthesis inhibitors MC-031 (O-demethylchlorothricin), -032 (O-demethylhydroxychlorothricin), -033 and -034.

In the course of our screening for microbial compounds which possessed inhibitory activities against biosynthesis of cholesterol from mevalonate, we isolated four new compounds from the cultural broth of Streptomyces sp. A7361. They are structurally related to, but distinct from chlorothricin.     

Identification of borinic esters as inhibitors of bacterial cell growth and bacterial methyltransferases, CcrM and MenH

As bacteria continue to develop resistance toward current antibiotics, we find ourselves in a continual battle to identify new antibacterial agents and targets. We report herein a class of boron-containing compounds termed borinic esters that have broad spectrum antibacterial activity with minimum inhibitory concentrations (MIC) in the low microgram/mL range. These compounds were identified by screening for inhibitors against Caulobacter crescentus CcrM, an essential DNA methyltransferase from gram negative alpha-proteobacteria. In addition, we demonstrate that borinic esters inhibit menaquinone methyltransferase in gram positive bacteria using a new biochemical assay for MenH from Bacillus subtilis. Our data demonstrate the potential for further development of borinic esters as antibacterial agents as well as leads to explore more specific inhibitors against two essential bacterial enzymes.     

Anti-viral activity of the extracts of a Kenyan medicinal plant Carissa edulis against herpes simplex virus

Herpes simplex virus (HSV) infection is a major opportunistic infection in immunosuppressed persons. It is therefore a serious disease in high HIV/AIDS prevalence areas as in sub-Saharan Africa where infections due to HSV have risen significantly. The development of resistant strains of HSV to the available drugs for infection management, as is evident in the first drug of choice acyclovir, has further compounded this situation. There is therefore an urgent need to identify and develop new alternative agents for management of HSV infections, more so, for those due to resistant strains. We report here on an aqueous total extract preparation from the roots of Carissa edulis (Forssk.) Vahl (Apocynaceae), a medicinal plant locally growing in Kenya that has exhibited remarkable anti-HSV activity in vitro and in vivo for both wild type and resistant strains of HSV. The extract significantly inhibited formation of plaques in Vero E6 cells infected with 100PFU of wild type strains of HSV (7401H HSV-1 and Ito-1262 HSV-2) or resistant strains of HSV (TK(-) 7401H HSV-1 and AP(r) 7401H HSV-1) by 100% at 50 microg/ml in vitro with minimal cell cytotoxicity (CC(50)=480 microg/ml). When the extract was examined for in vivo efficacy in a murine model using Balb/C mice cutaneously infected with wild type or resistant strains of HSV, the extract at an oral dose of 250 mg/kg significantly delayed the onset of HSV infections by over 50%. It also increased the mean survival time of treated infected mice by between 28 and 35% relative to the infected untreated mice (p<0.05 versus control by Student's t-test). The mortality rate for mice treated with extract was also significantly reduced by between 70 and 90% as compared with the infected untreated mice that exhibited 100% mortality. No acute toxicity was observed in mice at the oral therapeutic dose of 250 mg/kg. These results suggest that this herbal extract has potent anti-viral agents against herpes simplex viruses that can be exploited for development of an alternative remedy for HSV infections.     

The effects of Lactobacillus pentosus strain b240 and appropriate physical training on salivary secretory IgA levels in elderly adults with low physical fitness: a randomized,double-blind,placebo-controlled trial

The purpose of the study was to evaluate the effects of Lactobacillus pentosus strain b240 (b240) intake and appropriate physical training on salivary secretory immunoglobulin A secretion in elderly adults with low physical fitness. Elderly adults with low physical fitness (daily step count below 3,500 steps) were divided into 2 groups: a b240 intake + exercise group (b240 group) and a placebo intake + exercise group (placebo group). Each subject continued intake of b240 or placebo and moderate-intensity resistance exercise for 12 weeks. Before and 4, 8, and 12 weeks after the start of intervention, each subject underwent saliva sampling. Before and after intervention, physical fitness tests and step count were measured. Our results showed that secretory immunoglobulin A secretion in 57 subjects during the b240/placebo intake period was significantly greater in the b240 group than in the placebo group (p<0.05). There were no significant changes in physical fitness tests before and after intervention in the 2 groups. The daily amount of walking increased significantly after intervention in both groups (p<0.05). These results suggest that in elderly adults with low physical activity and fitness, intake of b240 with appropriate physical exercise elevate salivary secretory immunoglobulin A secretion.     

Effects of High-Intensity Endurance Exercise on Epidermal Barriers against Microbial Invasion

For athletes, preventing infectious disease on skin is important. Examination measurement of epidermal barriers could provide valuable information on the risk of skin infections. The aim of this study was to determine the effects of high-intensity endurance exercise on epidermal barriers. Six healthy adult males (age; 22.3 ± 1.6 years) performed bicycle exercise at 75%HR_max for 60 min from 18:30 to 19:30. Skin surface samples were measured 18:30 (pre), 19:30 (post), 20:30 (60 min), and 21:30 (120 min). Secretory immunoglobulin A (SIgA) and human β-defensin 2 (HBD-2) concentrations were measured using an enzyme-linked immunosorbent assay (ELISA). SIgA concentration at pre was significantly higher than at post, 60 min and 120 min (p < 0.05). HBD-2 concentration at post and 120 min was significantly higher than at pre (p < 0. 05). Moisture content of the stratum corneum was significantly higher at post than at pre, 60 min, and 120 min (p < 0.05). On the chest, moisture content of the stratum corneum was significantly lower at 120 min than at pre (p < 0.05). The number of staphylococci was significantly higher at post than at pre (p < 0.05), and tended to be higher at 60 min than at pre on the chest (p = 0. 08). High-intensity endurance exercise might depress the immune barrier and physical barrier and enhance the risk of skin infection. On the other hand, the biochemical barrier increases after exercise, and our findings suggest that this barrier might supplement the compromised function of other skin barriers.

Key points

• The immune barrier and physical barrier might be depressed and the risk of skin infection might be enhanced by high-intensity endurance exercise.
• The biochemical barrier increases after high-intensity endurance exercise and might supplement the compromised function of other skin barriers.
• We recommend that athletes maintain their skin surface in good condition, for example, by showering immediately after sports activities and using moisturizers.

Key words: Staphylococcus, skin infections, athletes, secretory immunoglobulin a, beta-defensins     

HIV attitudes, awareness and testing among older adults in Africa

In Africa, older adults aged 50 and older are still sexually active and play a critical role as caregivers, yet little is known about their attitudes towards HIV and awareness of services. In this study, surveys were conducted in nine African sites. A multilevel model was fitted to evaluate the relationship between age and outcome variables. The study reveals that people aged 50 years and older have lower levels of HIV-related knowledge and awareness than those aged 25–49. Older adults were less likely to have been tested for HIV and women aged 50 and older showed particularly low levels of awareness.