Multifunctional 58S Bioactive Glass/Silver/Cerium Oxide-Based Biocomposites with Effective Antibacterial, Cytocompatibility, and Mechanical Properties

58S bioactive glass (BG) has effective biocompatibility and bioresorbable properties for bone tissue engineering; however, it has limitations regarding antibacterial, antioxidant, and mechanical properties. Therefore, we have developed BGAC biocomposites by reinforcing 58S BG with silver and ceria nanoparticles, which showed effective bactericidal properties by forming inhibited zones of 2.13 mm (against Escherichia coli) and 1.96 mm (against Staphylococcus aureus; evidenced by disc diffusion assay) and an increment in the antioxidant properties by 39.9%. Moreover, the elastic modulus, hardness, and fracture toughness were observed to be increased by ∼84.7% (∼51.9 GPa), ∼54.5% (∼3.4 GPa), and ∼160% (∼1.3 MPam1/2), whereas the specific wear rate was decreased by ∼55.2% (∼1.9 × 10-11 m3/Nm). X-ray diffraction, high-resolution transmission electron microscopy, and field emission scanning electron microscopy confirmed the fabrication of biocomposites and the uniform distribution of the nanomaterials in the BG matrix. The addition of silver nanoparticles in the 58S BG matrix (in BGA) increased mechanical properties by composite strengthening and bactericidal properties by damaging the cytoplasmic membrane of bacterial cells. The addition of nanoceria in 58S BG (BGC) increased the antioxidant properties by 44.5% (as evidenced by the 2,2-diphenyl-1-picrylhydrazyl assay). The resazurin reduction assay and MTT assay confirmed the effective cytocompatibility for BGAC biocomposites against mouse embryonic fibroblast cells (NIH3T3) and mouse bone marrow stromal cells. Overall, BGAC resulted in mechanical properties comparable to those of cancellous bone, and its effective antibacterial and cytocompatibility properties make it a good candidate for bone healing.

Population Growth and Development of the Psocid Liposcelis fusciceps (Psocoptera: Liposcelididae) at Constant Temperatures and Relative Humidities

We investigated the effects of seven temperatures (22.5, 25.0, 27.5, 30.0, 32.5, 35.0, and 37.5°C) and four relative humidities (43, 55, 63, and 75%) on population growth and development of the psocid Liposcelis fusciceps Badonnel (Psocoptera: Liposcelididae). Results demonstrated that L. fusciceps did not survive at 43% RH, at all temperatures tested. At 55% RH, L. fusciceps did not survive at the highest three temperatures and no psocids survived at 37.5°C and 63% RH. The highest population growth was recorded at 30.0°C and 75% RH where populations increased 16-fold from an initial population of five females. L. fusciceps males have two to four nymphal instars, and the percentages of males with two, three, and four instars were 28, 70, and 2%, respectively. Female L. fusciceps have two to five instars, and the percentages of females with two, three, four, and five instars were 2, 33, 63, and 2%, respectively. The total developmental time for males was shorter than females. We developed temperature-dependent development equations for male and female eggs, individual nymphal, combined nymphal, and combined immature stages. Based on 30-d population growth, L. fusciceps can survive and multiply at a relative humidity of 55% at 22.5-30.0°C, but does better at 27.5-32.5°C and a higher relative humidity of 75%. Relative humidities of ≤ 63% and temperatures of ≥ 32.5°C are detrimental to L. fusciceps. These data provide a better understanding of L. fusciceps population dynamics and can be used to develop effective management strategies for this psocid.

Visual Outcome after Treatment with High Dose Intravenous Methylprednisolone in Indirect Traumatic Optic Neuropathy

BACKGROUND

Traumatic optic neuropathy is an acute injury of the optic nerve due to trauma. It is an ocular emergency, requiring early treatment though there is no proven standard treatment protocol for the condition. Various studies have shown improvement in vision after intravenous steroids, but not statistically significant. Studies have revealed even optical decompression surgery is not the ultimate treatment because of no significant improvement of vision. Our study aims to assess visual outcome after high dose (1 gram) of intravenous methylprednisolone in cases with indirect optic neuropathy.

METHODS

This was a non-randomized interventional study carried out in Kathmandu Medical College Teaching Hospital from May 1st 2013- June 1st 2014.

RESULTS

There were 10 cases with indirect traumatic optic neuropathy included in the study. Four cases received IV methylprednisolone and six cases were observed without steroid treatment. Traumatic optic neuropathy was observed more in males[8 (80%)]with higher number in age group 21-30 years old. The visual recovery after intravenous steroid treatment was rapid and beneficial in cases with vision better than Non Perception of Light (NPL), even in cases presented 4 days after the trauma.

CONCLUSIONS

There was rapid and beneficial improvement in visual acuity after high dose of intravenous steroid treatment in cases with indirect traumatic optic neuropathy with vision better than Non Perception of Light (NPL).

Corneal edema after phacoemulsification surgery in patients with type II diabetes mellitus

INTRODUCTION

Corneal edema delays early visual recovery after phacoemulsification surgery in diabetes mellitus.

OBJECTIVE

To compare corneal edema of eyes in patients with type II diabetes mellitus and in non-diabetics after phacoemusification surgery.

MATERIALS AND METHODS

A hospital-based, retrospective study involving 96 eyes that underwent phacoemulsification surgery for immature cataract at the Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, Kathmandu, Nepal was carried out. Evaluation was performed of 33 eyes in patients with diabetes mellitus (diabetic group) and of 63 eyes in patients without diabetes mellitus (non-diabetic group). All diabetic patients had controlled blood glucose for at least one week prior to the surgery. The operated eye was examined before surgery and on one day, one week, and one month after surgery. Intraocular pressure was measured on each visit.

MAIN OUTCOME MEASURES

The findings of post-operative corneal edema and visual acuity between the diabetic and non-diabetic groups were studied and compared.

RESULTS

There was no difference clinically in any pre-operative corneal examination between the diabetic and non-diabetic groups. The corneal edema after surgery was significantly higher in the diabetic group than in the non-diabetic group (p less than 0.001). The number of patients with corneal edema one day and one week after surgery was significantly higher in the diabetic group than in the non-diabetic group (after 1 day, OR = 62.5; 95 % CI = 15.31 - 255.11, p less than 0.000) and after 1 week, OR = 6.77; 95 % CI = 1.28 - 35.76, p less than 0.006).

CONCLUSION

Corneal edema following phacoemusification surgery in diabetic eyes is likely to be more frequent than in non-diabetic eyes.

Population growth and development of Liposcelis pearmani (Psocoptera: Liposcelididae) at constant temperatures and relative humidities

Psocids of genus Liposcelis are now considered serious pests of stored products. We investigated the effects of eight temperatures (22.5, 25.0, 27.5, 30.0, 32.5, 35.0, 37.5, and 40.0°C) and four relative humidities (43, 55, 63, and 75%) on population growth and development of the psocid Liposcelis pearmani Lienhard. L. pearmani did not survive at 37.5 and 40.0°C, at all relative humidities tested; at 43% RH, at all temperatures tested; and at 55% RH, at 32.5 and 35°C. The greatest population growth was recorded at 32.5°C and 75% RH (32-fold growth). L. pearmani males have two to four nymphal instars, and the percentages of males with two, three, and four instars were 17, 63, and 20%, respectively. Female L. pearmani have two to five instars, and the percentages of females with two, three, four, and five instars were 5, 39, 55, and 1%, respectively. We developed temperature-dependent development equations for male and female eggs, individual nymphal, combined nymphal, and combined immature stages. Based on 30-d population growth, L. pearmani cannot survive at temperatures >35.0°C; does not thrive at low relative humidities (55%), at temperatures above 25°C; and has a high optimum relative humidity for population growth (75%). Therefore, we expect it to have a more limited distribution compared with other Liposcelis species. These data provide a better understanding of how temperature and RH may influence L. pearmani population dynamics and can be used in population growth models to help develop effective management strategies for this psocid, and to predict its occurrence.

Comparison of microarray preprocessing methods

Data preprocessing in microarray technology is a crucial initial step before data analysis is performed. Many preprocessing methods have been proposed but none has proved to be ideal to date. Frequently, datasets are limited by laboratory constraints so that the need is for guidelines on quality and robustness, to inform further experimentation while data are yet restricted. In this paper, we compared the performance of four popular methods, namely MAS5, Li & Wong pmonly (LWPM), Li & Wong subtractMM (LWMM), and Robust Multichip Average (RMA). The comparison is based on the analysis carried out on sets of laboratory-generated data from the Bioinformatics Lab, National Institute of Cellular Biotechnology (NICB), Dublin City University, Ireland. These experiments were designed to examine the effect of Bromodeoxyuridine (5-bromo-2-deoxyuridine, BrdU) treatment in deep lamellar keratoplasty (DLKP) cells. The methodology employed is to assess dispersion across the replicates and analyze the false discovery rate. From the dispersion analysis, we found that variability is reduced more effectively by LWPM and RMA methods. From the false positive analysis, and for both parametric and nonparametric approaches, LWMM is found to perform best. Based on a complementary q-value analysis, LWMM approach again is the strongest candidate. The indications are that, while LWMM is marginally less effective than LWPM and RMA in terms of variance reduction, it has considerably improved discrimination overall.

Kartagener syndrome: a rare genetic disorder

Kartagener Syndrome is a rare autosomal recessive disorder consisting of triad of sinusitis, bronchiectasis and situs inversus with dextrocardia. It is the subset of disorder called primary ciliary dyskinesia in which the cilia have abnormal structure and/or function resulting in multisystem diseases of various severity. Clinical manifestations include lifelong, chronic upper and lower respiratory tract diseases secondary to ineffective mucociliary clearance. Early diagnosis and management of chest infections can prevent irreversible damage to lungs and prevent potential lifelong complications. This case report is on a patient who presented with long standing history of sinusitis, bronchiectasis and on examination situs inversus with dextrocardia.

Impact of heavy metals (copper, zinc, and lead) on the chlorophyll content of some mosses

The effects of the heavy metals copper (Cu), zinc (Zn), and lead (Pb) on the chlorophyll content of two mosses Thuidium delicatulum (L.) Mitt. and T. sparsifolium (Mitt.) Jaeg., as well as leafy liverwort Ptychanthus striatus (Lehm. & Linderb.) were examined to understand the impact of metal accumulation on the chlorophyll content of mosses and leafy liverwort, which are found only in uncontaminated sites of the Kathmandu valley. These plants were treated with different concentrations of CuCl(2, )ZnCl(2), and Pb(NO(3))(2), ranging from 10(-10) M to 10(-2) M, in isolation and in combination under experimental conditions. Metal accumulation in the plant bodies increased with metal concentrations. Cu accumulation showed a significant inhibitory effect on chlorophyll-a, chlorophyll-b, and total chlorophyll in the mosses and the leafy liverwort. An insignificant decrease in chlorophyll content in both Thuidium species, but a significant decrease in leafy liverwort, was observed after Zn and Pb accumulation. Chlorophyll-a decreased significantly in T. sparsifolium; chlorophyll-b and total chlorophyll decreased significantly in T. delicatulum; and all chlorophyll contents decreased insignificantly in P. striatus after accumulation of Cu+Zn+Pb ions together from mixed metal solution. The ratio of chlorophyll-a to -b decreased more rapidly in both Thuidium species, with higher concentrations occurring when Cu+Zn+Pb ions were together than when Cu, Zn, or Pb ions were alone. This indicated a more destructive effect of Cu metals on the chlorophyll contents of both Thuidium species. High concentrations of Cu are known to activate oxidative damage and alter cell-membrane properties by lipid peroxidation, thereby demonstrating the inhibitory effect on the enzymes involved in chlorophyll production. The greater loss of chlorophyll from heavy-metal accumulation in P. striatus than in T. delicatulum and T. sparsifolium may have been caused by relatively more K(+) efflux in leafy liverwort than in the mosses, thus indicating their differences in membrane integrity.

Acute Acute Renal Failure and Hepatic Disfunction in Malaria

The clinical presentations of severe and complicated malaria vary. The prognosis is poor when associatedwith cerebral malaria and acute renal failure. Clinical profile, biochemical parameters and outcome werestudied in 46 adult patients of malaria admitted in a tertiary care hospital between April 2002 to April2003. The age of the patients ranged from 15 to 60 years. Majority (n=30) of the patients were in age groupof 15 to 34 years. 67% of the patients were from terai belt. Mean duration of febrile illness was 10 days atthe time of presentation. 39% (n=18) patients had hepatic dysfunction and 22% (n=10) had acute renalfailure (ARF) according to WHO criteria. All patients with ARF were oligo-anuric and required dialysissupport. Four patients died of which three were patients with ARF and hepatic dysfunction. Althoughmalaria still remains a major health problem, malarial renal disease has not been formally reported previouslyfrom Nepal. Early initiation of antimalarial therapy, close observation for organ failure and early initiationof dialysis in ARF is instrumental in the recovery of the patient.Key Words: Malaria, Organ Failure.

Neonatal mortality and maternal health care in Nepal: searching for patterns of association

This study explores the factors associated with neonatal mortality and maternal health care in Nepal. The subjects were 4375 births reported in the 1996 Nepal Family Health Survey. Maternal and child health care was found to have a significant association with neonatal mortality, although preceding birth interval and sex of child had stronger effects. Four aspects of maternal care were found to be highly associated with region, household ownership of assets, mother's education and father's education. This indicates that accessibility, affordability and availability of maternal health care are important factors to consider in future research on neonatal mortality.

Association between diabetic retinopathy and serum lipoproteins level

Introduction: Diabetic retinopathy is the leading cause of blindness of working-age patients in the urban areas. Objective: To find out the association between diabetic retinopathy and serum lipoproteins in patients with diabetes mellitus Materials and methods: A community-based cross-sectional study involving 100 subjects with type II diabetes living in the cities of Kathmandu, Bhaktapur and Lalitpur of Nepal was carried out using a purposive sampling method. The retinopathy was classified according to the modified Airlie House classification of diabetic retinopathy. The patients with systolic hypertension were excluded. The blood sugar level was assessed by using glycosylated hemoglobin. The fasting serum lipoproteins were assessed by photometric enzymatic methods. Statistics: The SPSS version 10.0 software was used. The p value of <0.05 was considered significant. Results: The majority (n=91) of the patients were in the age group 31-60 years with the mean of 48.2 ± 9.5. The mean duration of diabetes mellitus in the patients with no-diabetic-retinopathy was 4 ±3.4 years and that in those with the retinopathy was 6.4 ± 4years, (p =0.006). The mean glycosylated hemoglobin level for no-diabetic-retinopathy group was 6.9 ±1.1 %, whereas for the diabetic retinopathy group, it was 7.7 ± 1.5% (p = 0.004). The mean values of serum lipoproteins when taken together were slightly higher in the diabetic retinopathy group than in the group with no-diabetic-retinopathy. The serum triglyceride value was higher in the group with diabetic retinopathy than in the group with no retinopathy. Serum triglyceride had a low degree of positive correlation with HbA1c value. Conclusion: There is no significant association between the serum lipoprotein levels and diabetic retinopathy in patients with type II diabetes mellitus. Serum triglyceride level has a low degree of positive correlation with HbA1c value. Keywords: diabetic retinopathy; lipoproteins; glycosylated hemoglobin DOI: 10.3126/nepjoph.v1i2.3684 Nep J Oph 2009;1(2):107-113