Efficacy of pentamidine-loaded chitosan nanoparticles as a novel drug delivery system for Leishmania tropica

The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.

An Investigation of Vascular Endothelial Growth Factor (VEGFR-1 and VEGFR-2) in Burn Wound Healing

Burn damage is a complicated trauma that causes local and general tissue edema as a result of cell breakage and capillary leak syndrome. Angiogenesis plays a key part in the mechanisms that are initiated by tissue damage (e.g., burns) since it works directly and precisely on endothelial cells. The primary mediators of angiogenesis are vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1 and VEGFR-2). This study aimed to figure out what functions VEGF and its receptors play in wound healing after burn, and the systemic release of VEGF in people following severe burn damage. This study included 23 burnt adult serum and 20 healthy controls. The enzyme-linked immunosorbent test was used to assess circulating VEGF serum levels and its receptors (VEGFR-1 and VEGFR-2). VEGF serum levels were considerably higher in this study, compared to VEGF levels in healthy controls. The levels of VEGFR-1 and VEGFR-2 have significantly risen; moreover, VEGF and its receptors have a significant impact on edema-related problems in severely burned individuals. Burn is a frequent disease that damages the skin and induces the production of mediators that cause neovasculature in the majority of patients. VEGF, which causes vasculogenesis and angiogenesis, is one of the most important factors in the skin.

Involvement of soluble proteins in growth and metabolic adjustments of drought-stressed Calligonum mongolicum seedlings under nitrogen addition

The planting of seedlings is the most effective measure for vegetation restoration. However, this practice is challenging in desert ecosystems where water and nutrients are scarce. Calligonum mongolicum is a sand-fixing pioneer shrub species, and its adaptive strategy for nitrogen (N) deposition and drought is poorly understood. Thus, in a pot experiment, we studied the impacts of four N levels (0, 3, 6, 9 gN·m^-2 ·year^-1 ) under drought or a well-watered regime on multiple eco-physiological responses of 1-year-old C. mongolicum seedlings. Compared to well-watered conditions, drought considerably influenced seedling growth by impairing photosynthesis, osmolyte accumulation and activity of superoxide dismutase and enzymes related to N metabolism. Nitrogen addition improved the productivity of drought-stressed seedlings, as revealed by increased water use efficiency, enhanced superoxide dismutase and nitrite reductase activity and elevated N and phosphorus (P) levels in seedlings. Nevertheless, the addition of moderate to high levels of N (6-9 gN·m^-2 ·year^-1 ) impaired net photosynthesis, osmolyte accumulation and nitrate reductase activity. N addition and water regimes did not markedly change the N:P ratios of aboveground parts; while more biomass and nutrients were allocated to fine roots to assimilate the insufficient resources. Soluble protein in assimilating shoots might play a vital role in adaptation to the desert environment. The response of C. mongolicum seedlings to N addtion and drought involved an interdependency between soluble protein and morphological, physiological and biochemical processes. These findings provide an important reference for vegetation restoration in arid lands under global change.

Role of endophytic Penicillium species and Pseudomonas monteilii in inducing the systemic resistance in okra against root rotting fungi and their effect on some physiochemical properties of okra fruit

AIMS

The efficacy of three isolates of endophytic Penicillium species that have shown significant suppressive effect on root rotting fungi in our previous study were further evaluated in pots and field plot experiments for their effect on root diseases of okra, induction of systemic resistance and physiochemical properties of okra fruit.

METHODS AND RESULTS

Aqueous suspensions of endophytic Penicillium and Pseudomonas monteilii were applied in pots and field plots using okra as test plant. Data on the fungal infection of roots, plant growth, plant resistance markers like polyphenol, salicylic acid and antioxidant status of plant were determined. These isolates significantly suppressed root diseases and induced systemic resistance via increasing level of resistance markers, polyphenol and salicylic acid besides improving antioxidant activity of Penicillium and P. monteilii-treated plants as compared to control plants. GC-MS analysis of n-hexane extract of mycelium of P. nigricans revealed the presence of 15 different volatile compounds.

CONCLUSIONS

Endophytic Penicillium and P. monteilii have potential against root-infecting fungi of okra and can improve plant growth and yield.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic Penicillium species and P. monteilii can suppress root rotting fungi by direct mechanism or induction of systemic resistance in plants.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

A Modified Technique in Submandubular Salivary Gland Excision: Preservation of Facial Artery

Cutting and ligation of facial artery is the conventional practice for excision of submandibular gland. Facial artery is the main arterial supply to the lower face. Its preservation results in preservation of large proportion of vascularity to the lower face, preserves vascularity of platysma myocutaneous flap, allows repair of lower lip using Bernard's technique; facial artery is one of the most important recipient artery for microvascular free flap in modern reconstructive surgery in head and neck oncology. This prospective study was carried out in Department of Otolaryngology, Bangabandhu Sheikh Mujib Medical University Hospital (BSMMU), Dhaka, Bangladesh from October 2005 to October 2012 on 31 cases. Chronic submandibular sialoadenitis, benign submandibular gland tumours and cases of neck dissection where level I cervical lymph nodes were not involved by metastasis were included in this study. The facial artery was identified proximal to the gland and was dissected free from the gland by ligating or cauterizing its glandular branches to mobilize the gland. Appropriate anatomical aspects were noted and the time required for separation of the artery from the gland was recorded. Thirty-one consecutive cases were studied. The indications were chronic sialoadenitis (67.7%), pleomorphic adenoma (12.9%) and as a part of neck dissection for oncologic clearance of neck (19.4%). The mean duration of time for separation of the artery from the gland was 10.26 minutes. In two cases the facial artery could not be safely separated due to excessive adhesion from chronic inflammation. No significant complications were noted. Preservation of facial artery in submandibular gland excision is a simple procedure. So it should not be routinely sacrificed during this surgery.

Real-time forecasting of epidemic trajectories using computational dynamic ensembles

Forecasting the trajectory of social dynamic processes, such as the spread of infectious diseases, poses significant challenges that call for methods that account for data and model uncertainty. Here we introduce an ensemble model for sequential forecasting that weights a set of plausible models and use a frequentist computational bootstrap approach to evaluate its uncertainty. We demonstrate the feasibility of our approach using simple dynamic differential-equation models and the trajectory of outbreak scenarios of the Ebola Forecasting Challenge. Specifically, we generate sequential short-term forecasts of epidemic outbreaks by combining phenomenological models that incorporate flexible epidemic growth scaling, namely the Generalized-Growth Model (GGM) and the Generalized Logistic Model (GLM). We rely on the root-mean-square error (RMSE) to quantify the quality of the models' fits during the calibration periods for weighting their contribution to the ensemble model while forecasting performance was evaluated using the RMSE of the forecasts. For a given forecasting horizon (1-4 weeks), we report the performance for each model as the percentage of the number of times each model outperforms the other models. The overall mean RMSE performance of the GLM and the GGM-GLM ensemble models outcompeted that of participant models of the Ebola Forecasting Challenge. We also found that the ensemble model provided more accurate forecasts with higher frequency than the GGM and GLM models, but its performance varied across forecasting horizons. For instance, across all of the Ebola Challenge Scenarios, the ensemble model outperformed the other models at horizons of 2 and 3 weeks while the GLM outperformed other models at horizons of 1 and 4 weeks.

Restraining the multidrug efflux transporter STY4874 of Salmonella Typhi by reserpine and plant extracts

Efflux-mediated multidrug resistance is a well-known phenomenon facilitated by multidrug resistant (MDR) transporters. One of the approaches to counteract efflux-mediated resistance is the use of MDR pump inhibitors, and thus be used in combination with the conventional antibiotics to treat deadly diseases like typhoid fever. We have previously reported that STY4874, an efflux transporter of Salmonella serotype Typhi, exhibited promising characteristics as MDR pump. In this study, we aimed to get an insight into possible STY4874 inhibitors of plant origin. STY4874 was overexpressed in Escherichia coli and extracts from pomegranate peel, milk thistle seeds and reserpine, a synthetic plant alkaloid, were screened for inhibition of ciprofloxacin efflux. The extracts of milk thistle seeds and reserpine when incubated with ciprofloxacin showed statistically significant STY4874-mediated inhibitory activity, rendering the efflux pump inactive and hence early growth inhibition of host cells compared with cells expressing efflux pump and incubated only with ciprofloxacin. This efflux pump inhibitory activity was further confirmed by time-kill experiments. This study is the first to report on efflux pump inhibition of S. Typhi STY4874 and results can be extended towards its close homologues such as MdfA and MdtM from E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding and combating resistance governed by multidrug efflux transporters is an ongoing research intensive area, affecting treatment of various nosocomial and endemic/epidemic infections. Confronting drug resistance requires that inhibitors debilitating the underlying mechanisms should be included in combination therapy. One such example is the prescription of clavulanic acid as combination therapy with amoxicillin, collectively called as co-amoxiclav to combat β-lactamase-mediated resistance. However, research related to finding the inhibitors of efflux transporters, the resistance mechanism distinct from β-lactamase mediated resistance is at an early stage. The current study finds that plant-derived inhibitors can be an option towards restraining efflux-mediated resistance.

Design challenges for electronic medication administration record systems in residential aged care facilities: a formative evaluation

INTRODUCTION

Electronic medication administration record (eMAR) systems are promoted as a potential intervention to enhance medication safety in residential aged care facilities (RACFs). The purpose of this study was to conduct an in-practice evaluation of an eMAR being piloted in one Australian RACF before its roll out, and to provide recommendations for system improvements.

METHODS

A multidisciplinary team conducted direct observations of workflow (n=34 hours) in the RACF site and the community pharmacy. Semi-structured interviews (n=5) with RACF staff and the community pharmacist were conducted to investigate their views of the eMAR system. Data were analysed using a grounded theory approach to identify challenges associated with the design of the eMAR system.

RESULTS

The current eMAR system does not offer an end-to-end solution for medication management. Many steps, including prescribing by doctors and communication with the community pharmacist, are still performed manually using paper charts and fax machines. Five major challenges associated with the design of eMAR system were identified: limited interactivity; inadequate flexibility; problems related to information layout and semantics; the lack of relevant decision support; and system maintenance issues. We suggest recommendations to improve the design of the eMAR system and to optimize existing workflows.

DISCUSSION

Immediate value can be achieved by improving the system interactivity, reducing inconsistencies in data entry design and offering dedicated organisational support to minimise connectivity issues. Longer-term benefits can be achieved by adding decision support features and establishing system interoperability requirements with stakeholder groups (e.g. community pharmacies) prior to system roll out. In-practice evaluations of technologies like eMAR system have great value in identifying design weaknesses which inhibit optimal system use.

Are soft tissue measurements on lateral cervical spine X-rays reliable in the assessment of traumatic injuries?

INTRODUCTION

Traumatic neck pain is a common presentation to the emergency department. Lateral plain radiographs remain the primary investigation in the assessment of these injuries. Soft tissue assessment forms an integral component of these radiographs. They can provide information on subtle injuries that may not be obvious. Many methods are used to assess the prevertebral soft tissue shadows. The two more commonly used techniques include the 'seven at two and two at seven' rule (method 1) and the ratio of the soft tissues with respect to the vertebral width (method 2).

AIM

To assess which of the above two methods in assessing cervical spine soft tissue shadows on lateral radiographs is more sensitive in the presence of cervical spine injuries.

METHODS

A retrospective analysis of consecutive traumatic cervical spine films performed within a busy trauma tertiary centre over a period of 7 months. Patients were divided into two groups: group 1-fractures; group 2-no fractures. The prevertebral soft tissue shadows were measured at referenced points on the lateral cervical spine films with respect to the above two methods and comparisons between the groups were made.

RESULTS

Thirty-nine patients in group 1 were compared to a control group of 60 patients in group 2. Both methods failed to identify any significant differences between the two groups. The sensitivity and specificity for method 1 was 7.6 and 93 %, and for method 2, they were 7.6 and 98 %, respectively.

CONCLUSION

There is no significant difference between the soft tissue shadows when comparing patients with and without cervical spine fractures on lateral radiographs. Both commonly used measures of soft tissue shadows in clinical practice are insensitive in identifying patients with significant osseous injuries. They, therefore, do not offer any further value in interpreting traumatic cervical spine radiographs. The management of patients with cervical spine trauma in the absence of obvious osseous injury on standard radiographs should warrant a computed tomography (CT) scan if clinically indicated.

Endoscopic dacryocystorhinostomy

Dacryocystorhinostomy (DCR) is the treatment of distal nasolacrimal duct blockage. It has got many advantages of over external DCR with higher patient's acceptance. Twenty one consecutive cases of endoscopic DCR were studied during the period of two and a half years with a mean follow up period of 13.12 months (SD=7.05). The mean age of cases was 42.95 years (SD=14.49). In most of the cases the cause was either idiopathic (71.43%) or inflammatory (23.81%). The techniques used for making bony window were chisel-hammer (19.50%), powered drill (23.81%), Kerrison punch forceps (14.29%) or combination of powered drill and Kerrison punch forceps (42.86%). Silicon stent was used in 71.43% cases. There was no significant peroperative complication; premature extrusion of stent (4.76%), synaechia (9.52%), excessive granulation tissue formation (9.52%) and stomal stenosis with recurrence of symptoms (9.52%) were the complications noticed here. Anatomical success with patent stoma was observed in 90.48% cases but symptomatic improvement with dry comfortable eyes were seen in 86% cases. There was no statistically significant difference of outcome between this study and that of recently published studies (p>0.05). Some comparative studies showed both higher and lower success rates of endoscopic DCR than external procedure but there was no significant difference (p>0.05).

Audit on the success of partner notification for sexually transmitted infections in the West Midlands

The aim of this study is to investigate the success of partner notification (PN) among 13 genitourinary medicine centres in West Midlands. The West Midlands Audit Group conducted a regional audit between June and August 2007. Information on screening and management of patients with chlamydia, gonorrhoea, early syphilis and HIV were collected separately. Participating centres were asked to provide PN details for 10 index patients with each of chlamydia, gonorrhoea, early syphilis and HIV infections. For each index patient with chlamydia or gonorrhoea, 0.54 and 0.44 partners were screened, respectively. Among partners of patients with syphilis and HIV, 24% and 35% were screened, respectively. Only 9% of 311 screened partners were involved in casual partnerships with index patients. Acquisition of more robust targets for PN, better documentation, improved communication between genitourinary (GU) medicine centres, and provider referral may improve the performance of PN for Sexually transmitted infections.

An audit on the management of pelvic inflammatory disease in the West Midlands, UK

The potential complications of pelvic inflammatory disease (PID) make optimizing its management a high priority. A clinical audit of PID against current national management guidelines was conducted in 14 departments of genitourinary medicine in the West Midlands for women presenting with PID between January and December 2005. There were a total of 810 diagnoses of PID made from a total of 49,390 female attendees for that year, giving an incidence of 164 cases per 10,000 attendees. Of these 810 cases, data collection and analysis for this audit were performed on 139. An ofloxacin 400 mg twice daily (b.i.d.) based regimen was prescribed in 91 (65%, 95% confidence interval [CI] 57-73%) cases. Doxycycline 100 mg b. i. d. for 14 days plus metronidazole 400 mg b. i. d. for 5-14 days was prescribed in 44 (32%, 95% CI 25-40%) cases, but a third-generation cephalosporin was only given with this regimen in three cases. Partner notification was performed in 101 (73%, 95% CI 65-79%) cases. A total of 130 male contacts were recorded on the data collection forms, and of these 58 (45%) were traced and 51 (39%), treated. A follow-up appointment was given to 133 (96%, 95% CI 91-98%) women, although in most cases this was for seven days or more, and 104 (78%, 95% CI 67-81%) women attended for follow-up. Adherence to the national guidelines in this cohort of patients did not reach the national standard for choice of treatment regimen nor did it attain the target for proportion of male partners traced. Barriers preventing adherence to the national guidelines need to be explored and appropriate assistance given to physicians to help meet national standards of care.

Epilepsy: public knowledge and attitude in a slum area of Karachi, Pakistan

BACKGROUND

Epilepsy is a common but widely misunderstood illness. Consequently, epileptics suffer from considerable stigmatization in society. Since no studies have detailed the misperceptions about epilepsy in our community, it is not possible to provide focused intervention aimed at eliminating this prejudice.

PURPOSE

To assess the knowledge and attitude regarding epilepsy in an adult population of a Karachi slum area.

METHODS

A face-to-face interview was conducted on 487 consenting adult non-epileptics (305 males; 182 females) who were conveniently sampled. Chi-square test was employed to calculate the variability in knowledge and attitude with demographic and other variables.

RESULTS

In all, 12.5% had never heard about epilepsy. Among the rest, 66.7% identified epilepsy as being non-infectious, while 28.2% were unaware of any treatment available for it. Among the other 71.8%, 62.7% were aware of the existence of anti-epileptic drugs. Religious/spiritual treatment was chosen as the most effective treatment by 33.1%. Males were more likely to identify epilepsy as being non-infectious (p=0.02). Nearly 18% of the respondents would not object to their child marrying an epileptic, 69.5% did not want to socially isolate the epileptics, 83.1% said epileptics could receive academic education, 85.6% said they could perform activities of daily life and 62.4% said they could become useful members of the society. Those who considered epilepsy to be infectious were more likely to carry negative attitudes towards epilepsy (p<0.01 with four attitudes).

CONCLUSIONS

Considerable gaps exist in the community's knowledge about epilepsy. Some of these may explain the prevalence of negative attitudes towards this ailment.

Reducing the risk of gonorrhoea in black Caribbean men: can we identify risk factors?

OBJECTIVES

Grouping patients by self assigned ethnicity may hide intraethnic differences in disease associations and sexual behaviour patterns. The aim of the study was to detect associations between gonorrhoea with differences in ancestry, degree of acculturation, and religious belief in young black Caribbean men, which could subsequently be used to target health promotion interventions.

METHODS

A questionnaire based case-control study of black Caribbean men with gonorrhoea and a community control group without gonorrhoea.

RESULTS

A lesser degree of acculturation, attending a single sex school, increasing numbers of partners, lack of condom use, not being married, and a belief that sex before marriage was not wrong were associated with an increased risk of gonorrhoea. Country of birth and religious belief were not associated with gonorrhoea.

CONCLUSIONS

A number of factors were identified which may be useful in designing healthcare interventions in young black Caribbean men and these differed little from those in other ethnic groups. The healthcare intervention should include advice on reducing the number of partners and increasing the use of condoms.

Audit of official STD returns from genitourinary medicine

We audited the accuracy of KC 60 coding in our department over a two-week period in 1999. Case notes of 400 consecutive new and rebook patients who attended during each of the audit periods were reviewed, and their clinical diagnosis was compared with KC 60 returns entered into the computer and sent to the Department of Health. We concentrated on four KC 60 diagnoses of positive sexually transmitted infections: uncomplicated gonorrhoea (B1) and chlamydia (c4a), first episodes of anogenital warts (C 11 a) and herpes (C 10 a). At the end of the audit, specific recommendations were introduced, aiming at improving accuracy of KC 60 coding, and a re-audit was carried out in 2000, using identical methodology. In the first audit period there were 106 positive diagnoses, of which 41 (38.7%) were not recorded in the KC 60 returns. In the second audit period there were 149 positive diagnoses, of which 20 (13%) were not recorded, showing a significant improvement (Chi square P = 0.0005).

Seroprevalence of hepatitis A immunity in male genitourinary medicine clinic attenders: a case control study of heterosexual and homosexual men

OBJECTIVES

To compare the seroprevalence of hepatitis A in homosexual and heterosexual men to determine their susceptibility to infection and provide guidance for a policy on vaccination.

METHODS

A case-control study design was utilised to compare the risk factors associated with hepatitis A in homosexual and heterosexual men attending a city centre genitourinary medicine clinic. Demographic and sexual behavioural characteristics were included in univariate and multivariate models.

RESULTS

The overall seropositivity rate was 29% with no significant difference between homosexual and heterosexual men. Ethnicity and age were strongly associated with hepatitis A seropositivity in both homosexuals and heterosexuals. A history of sex in a sauna in homosexual men, and being born outside the United Kingdom for heterosexual men, was associated with hepatitis A seropositivity.

CONCLUSIONS

Targeted hepatitis A screening and vaccination of homosexual men attending UK genitourinary medicine clinics is not supported by the results of this study.

Viral sexually transmitted infections: current management strategies

Viral sexually transmitted infections are a major health problem associated with considerable morbidity. This article reviews the current strategies used in the management of infections such as genital warts, genital herpes and molluscum contagiosum. Pros and cons of different treatment regimens have been discussed with an emphasis on a selective approach to therapy. The importance of education, counselling and follow-up is highlighted and issues relating to the associated psychosexual morbidity have been addressed. Treatment of these infections in pregnancy and HIV has also been described.