Antiinflammatory effect of low-level laser therapy on Staphylococcus epidermidis endophthalmitis in rabbits

Clinical Profile, Antibiotic Resistance and Outcomes in Bacterial Endophthalmitis: Coagulase-Negative Staphylococcus Endophthalmitis as Compared to Other Organisms

BACKGROUND

To evaluate the clinical profile, outcomes and antibiotic resistance in bacterial endophthalmitis.

METHODS

This was a post-hoc analysis of a study conducted at a tertiary centre, where 60 consecutive cases of culture-proven bacterial endophthalmitis were included prospectively. Group 1 included coagulase-negative Staphylococcus endophthalmitis (CNSE), while group 2 included the remaining cases. Clinical features, antibiotic resistance and visual outcomes were compared. Visual acuity >3/60 at six months of follow-up was defined as a good visual outcome.

RESULTS

Group 1 had 31 cases, while group 2 had 29. Group 2 included 12 gram-positive and 17 gram-negative isolates. Among the groups, group 2 had more patients with presenting visual acuity below hand motions close to the face (25 vs. 12, p<0.001), poor visual outcomes (26 vs. 3, p<0.001) and retinal detachment (RD) (10 vs. 2, p=0.007). Pseudomonas was most commonly resistant to antibiotics, and ceftazidime (p=0.005) and cefazolin (p=0.009) resistance were higher in group 2 isolates. In group 1, five isolates were resistant to any one of the antibiotics, whereas in group 2, 13 isolates were resistant to any one of the antibiotics (p=0.024).

CONCLUSIONS

In the current study, eyes in the group of endophthalmitis caused by CNSE achieved better visual acuities at the last follow-up compared to eyes with endophthalmitis caused by other bacteria. Antibiotic resistance in isolates other than CNSE is a cause of concern.

Radioreparative Effect of Diode Laser on Leukopoiesis Recovery: A Pilot Study

The aim of the present study was to investigate the effect of laser therapy on leukopoiesis recovery after irradiation with ionizing radiation. A dose of ionizing radiation was used that induced the hematological form of radiation sickness, reducing the number of blood cells. Subsequently, mice were treated with non-ionizing laser radiation. Based on the examination of the peripheral blood, the study found that laser therapy significantly impacted the number of eosinophils and basophils two weeks after irradiation. Laser therapy also led to the faster reparation of the lymphocyte lineage of white blood cells (WBCs). The research showed that the examined therapeutic laser had a long-term radioreparative effect on gamma-irradiated mice, improving the absolute counts of different lines of WBCs. The results of this study could have implications for the treatment of radiation sickness in humans.

Impact of Combined Photo-Biomodulation and Aerobic Exercise on Cognitive Function and Quality-of-Life in Elderly Alzheimer Patients with Anemia: A Randomized Clinical Trial

Purpose

Few data are available on the positive impact of photo-biomodulation (PBM) using low-level laser therapy as a complementary treatment for improving the cognitive function and optimizing the hemoglobin (Hb) level and oxygen carrying capacity in anemic elderly patients and consequently improving the quality-of-life. The present study aimed to evaluate a new, safe, and easy therapeutic approach to improve Alzheimer’s disease-related symptoms that interfere with the whole life activities and social interaction of elderly patients.

Patients and Methods

In this placebo-controlled clinical trial, 60 elderly patients suffering from anemia and mild cognitive dysfunction were randomly assigned into two equal groups to receive active or placebo low-level laser in addition to a moderate-intensity aerobic exercise over a 12-week period. Hb level as well as cognitive and functional tests were reassessed for any change after 12 weeks of intervention.

Results

By the end of this study, both groups showed significant improvements in Hb level, Montreal Cognitive Assessment Scale (MoCa – B basic), Quality-of-Life for Alzheimer’s Disease scale, and Berg Balance scale scores along with significant reduction in body mass index (BMI) and waist–hip ratio (WHR) (P<0.0001). The experimental group which received active low-level laser in addition to moderate-intensity aerobic exercise showed more significant results compared to the control group which received placebo low-level laser in addition to moderate-intensity aerobic exercise in all the measured outcomes (P<0.001).

Conclusion

Combined low-level laser therapy and moderate-intensity aerobic exercises are more effective in improving the cognitive function and quality-of-life of Alzheimer’s disease patients.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier NCT04496778.

Baihui Point Laser Acupuncture Ameliorates Cognitive Impairment, Motor Deficit, and Neuronal Loss Partly via Antioxidant and Anti-Inflammatory Effects in an Animal Model of Focal Ischemic Stroke

Stroke is recognized as one of the most dangerous killer diseases in Thailand and other countries worldwide. The development of a novel strategy for treating stroke patients is therefore urgently required. The present study investigated the effect of laser acupuncture at the Baihui point on cognitive and functional recovery, neuronal loss, antioxidant enzyme activities, and interleukin-6 (IL-6) activity in the hippocampus in an animal model of focal ischemic stroke. Male Wistar rats were randomly divided into 4 groups: sham operation; permanent occlusion of the right middle cerebral artery (Rt.MCAO); Rt.MCAO with sham laser acupuncture; and Rt.MCAO with Baihui point laser acupuncture. Laser acupuncture at the Baihui point and sham acupuncture at a nonacupoint were performed once daily (10 min at each point) for 14 days after Rt.MCAO. Half of the rats in each group were examined to determine neuron density by Cresyl violet staining, while the other half were examined by biochemical assays to measure glutathione peroxidase (GSH-Px) in the hippocampus, superoxide dismutase (SOD) in mitochondria and interleukin-6 (IL-6) activity in the hippocampus. Laser acupuncture treatment was found to significantly enhance memory and neuron density in CA1 and CA3. Improved neurological score, improved GSH-Px and SOD activities, and decreased density ratio of IL-6 to β-actin were also observed in the hippocampus. In conclusion, Baihui point laser acupuncture alleviates cognitive impairment and motor deficits via antioxidant and anti-inflammatory effects in focal ischemic rats. Further study is warranted to investigate other possible mechanisms of action.

Intravitreal Infliximab Injection to Treat Experimental Endophthalmitis

Objective

The purpose of this study was to compare the use of an intravitreal injection of infliximab and of dexamethasone combined with vancomycin to treat experimental endophthalmitis induced by Staphylococcus epidermidis.

Materials and Methods

The study was conducted between March 25 and April 13, 2012. Twenty-five six-month-old healthy rabbits were used, each weighing 2.5-3 kg. The rabbits were randomized into five groups with five animals per group. Endophthalmitis was induced by 0.1 mL (103 colony-forming units) S. epidermidis in all groups. In group 1, injection was not implemented after the occurrence of endophthalmitis. In groups 2, 3, and 4, the following intravitreal injections were given 24 h after the occurrence of endophthalmitis: group 2, 0.1 mg/0.1 mL vancomycin; group 3, 1 mg/0.1 mL vancomycin and 1 mg/0.1 mL dexamethasone; and group 4, 1 mg/0.1 mL vancomycin and 2 mg/0.1 mL infliximab. Group 5 was the control/uninfected group. The rabbits were clinically assessed each day for seven days. On day 9, a histopathologic evaluation was performed after enucleation.

Results

After a clinical evaluation, no statistically significant difference was found between the vancomycin+infliximab and vancomycin+dexamethasone groups (p>0.05). The difference was significant when both groups were compared with the vancomycin group (p<0.001). After the histopathologic evaluation, no statistically significant difference was found among the three groups (p>0.05).

Conclusion

An intravitreal injection of infliximab and of dexamethasone combined with vancomycin have similar clinical and histopathologic effects. To supplement the antibiotic treatment of endophthalmitis, infliximab in a safe dose range can be used as an alternative to dexamethasone to suppress inflammation and prevent ocular damage.

A pilot study into the effect of low-level laser therapy in patients with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a common inflammatory disease of the nose and paranasal sinuses that has a significant impact on patients' quality of life. No study has examined the effectiveness of applying low-level laser therapy (LLLT) locally over the sinuses in patients with CRS. The aim of this study was to evaluate the effect of LLLT in patients with CRS. Fifteen adult patients with CRS participated in this pilot pretest-posttest clinical study. Patients were treated with a 830-nm Ga-Al-As laser in continuous-wave mode at a power output of 30 mW and energy dose of 1 J. Laser irradiation was delivered on six points over each maxillary or frontal sinus with 33 sec irradiation for each point and a total treatment duration of 198 sec for each sinus. Patients were given LLLT three times per week for ten treatment sessions. Patients were asked to score their symptoms in accordance with a four-point scale (0-3), and a total symptom score (TSS) for each patient was calculated. Percentage improvement of TSS was considered as the primary outcome measure. TSS was calculated at baseline (T0), at 2 weeks (T1) and at 4 weeks (T2). The TSS was improved significantly at T1 (39%) and at T2 (46.34%). A large effect size for LLLT was found (ηp(2) ηp(2)  =  0.63). The therapeutic effect was sustained for a mean of 5 months. This pilot study indicates that LLLT applied for 4 weeks improves symptoms in patients with CRS.

Effect of low-level laser therapy on allergic asthma in rats

Asthma is a complex chronic inflammatory disease of the airways that involves the activation of many inflammatory and other types of cells. We investigated the effect of low-level laser therapy (LLLT) on allergic asthma in rats and compared its effect with that of the glucocorticoid budesonide. Asthma was induced by challenge and repeated exposure to ovalbumin. Asthmatic rats were then treated with LLLT or budesonide suspension. LLLT at 8 J/cm(2) once daily for 21 days could relieve pathological damage and airway inflammation in asthmatic rats. LLLT could decrease the total numbers of cells and eosinophils in bronchoalveolar lavage fluid. LLLT could reduce levels of IL-4 and increase IFN-γ levels in bronchoalveolar lavage fluid and serum, meanwhile reduce serum IgE levels. Flow cytometry assay showed that LLLT can regulate the Th1/Th2 imbalance of asthmatic rats. LLLT had a similar effect to that of budesonide. These findings suggest that the mechanism of LLLT treatment of asthma is by adjustment of Th1/Th2 imbalance. Thus, LLLT could take over some of the effects of budesonide for the treatment of asthma, thereby reducing some of the side effects of budesonide.

Intraocular pressure changes: an important determinant of the biocompatibility of intravitreous implants

BACKGROUND

In recent years, research efforts exploring the possibility of using biomaterial nanoparticles for intravitreous drug delivery has increased significantly. However, little is known about the effect of material properties on intravitreous tissue responses.

PRINCIPAL FINDINGS

To find the answer, nanoparticles made of hyaluronic acid (HA), poly (l-lactic acid) (PLLA), polystyrene (PS), and Poly N-isopropyl acrylamide (PNIPAM) were tested using intravitreous rabbit implantation model. Shortly after implantation, we found that most of the implants accumulated in the trabecular meshwork area followed by clearance from the vitreous. Interestingly, substantial reduction of intraocular pressure (IOP) was observed in eyes implanted with particles made of PS, PNIPAM and PLLA, but not HA nanoparticles and buffered salt solution control. On the other hand, based on histology, we found that the particle implantation had no influence on cornea, iris and even retina. Surprisingly, substantial CD11b+ inflammatory cells were found to accumulate in the trabecular meshwork area in some animals. In addition, there was a good relationship between recruited CD11b+ cells and IOP reduction.

CONCLUSIONS

Overall, the results reveal the potential influence of nanoparticle material properties on IOP reduction and inflammatory responses in trabecular meshwork. Such interactions may be critical for the development of future ocular nanodevices with improved safety and perhaps efficacy.