Surface-enhanced Raman spectroscopy for the study of interaction of an antibacterial agent ([bis(1,3-dipentyl-1H-imidazol-2(3H)-ylidene)silver(i)]bromide) with Bacillus subtilis bacterial biofilms.

Bacterial resistance towards antibiotics is a significant challenge for public health, and surface-enhanced Raman spectroscopy (SERS) has great potential to be a promising technique to provide detailed information about the effect of antibiotics against biofilms. SERS is employed to check the antibacterial potential of a lab synthesized drug ([bis(1,3-dipentyl-1H-imidazol-2(3H)-ylidene)silver(i)] bromide) against Bacillus subtilis and to analyze various SERS spectral features of unexposed and exposed Bacillus strains by observing biochemical changes in DNA, protein, lipid and carbohydrate contents induced by the lab synthesized imidazole derivative. Further, PCA and PLS-DA are employed to differentiate the SERS features. PCA was employed to differentiate the biochemical contents of unexposed and exposed Bacillus strains in the form of clusters of their representative SERS spectra and is also helpful in the pairwise comparison of two spectral data sets. PLS-DA provides authentic information to discriminate different unexposed and exposed Bacillus strains with 91% specificity, 93% sensitivity and 97% accuracy. SERS can be employed to characterize the complex and heterogeneous system of biofilms and to check the changes in spectral features of Bacillus strains by exposure to the lab synthesized imidazole derivative.

Surface-enhanced Raman spectroscopy for characterization of filtrates of blood serum samples from patients with tuberculosis obtained by 50 kDa filtration devices.

The ability of surface-enhanced Raman spectroscopy (SERS) to generate spectroscopic fingerprints has made it an emerging tool for biomedical applications. The objective of this study is to confirm the potential use of Raman spectroscopy for early disease diagnosis based on blood serum. In this study, a total of sixty blood serum samples, consisting of forty from diseased patients and twenty (controls) from healthy individuals, was used. Because disease biomarkers, found in the lower molecular weight fraction, are suppressed by higher molecular weight proteins, 50 kDa Amicon ultrafiltration centrifugation devices were used to produce two fractions from whole blood serum consisting of a filtrate, which is a low molecular weight fraction, and a residue, which is a high molecular weight fraction. These fractions were then analyzed, and their SERS spectral data were compared with those of healthy fractions. The SERS technique was utilized on blood serum, filtrate and residue of patients with tuberculosis to identify characteristic SERS spectral features associated with the development of disease, which can be used to differentiate them from healthy samples using silver nanoparticles as a SERS substrate. For further analysis, the effective chemometric technique of principal component analysis (PCA) was used to qualitatively differentiate all the analyzed samples based on their SERS spectral features. Partial least squares discriminant analysis (PLS-DA) accurately classified the filtrate portions of healthy and tuberculosis samples with 97% accuracy, 97% specificity, 98% sensitivity, and an area under the receiver operating characteristic (AUROC) curve of 0.74.

Teleguidance-based remote navigation assistance for visually impaired and blind people-usability and user experience.

This paper reports the development of a specialized teleguidance-based navigation assistance system for the blind and the visually impaired. We present findings from a usability and user experience study conducted with 11 blind and visually impaired participants and a sighted caretaker. Participants sent live video feed of their field of view to the remote caretaker's terminal from a smartphone camera attached to their chest. The caretaker used this video feed to guide them through indoor and outdoor navigation scenarios using a combination of haptic and voice-based communication. Haptic feedback was provided through vibrating actuators installed in the grip of a Smart Cane. Two haptic methods for directional guidance were tested: (1) two vibrating actuators to guide left and right movement and (2) a single vibrating actuator with differentiating vibration patterns for the same purpose. Users feedback was collected using a meCUE 2.0 standardized questionnaire, interviews, and group discussions. Participants' perceptions toward the proposed navigation assistance system were positive. Blind participants preferred vibrational guidance with two actuators, while partially blind participants preferred the single actuator method. Familiarity with cane use and age were important factors in the choice of haptic methods by both blind and partially blind users. It was found that smartphone camera provided sufficient field of view for remote assistance; position and angle are nonetheless important considerations. Ultimately, more research is needed to confirm our preliminary findings. We also present an expanded evaluation model developed to carry out further research on assistive systems.

Oral misoprostol versus oxytocin in the management of third stage of labour.

OBJECTIVES: To compare oral misoprostol versus intramuscular oxytocin in the management of third stage of labour. METHODS: The quasi-experimental study was conducted at the Obstetrics and Gynaecology Unit II, Civil Hospital, Karachi, from June 20 to December 19, 2006. A total of 70 patients diagnosed in active phase of labour who fulfilled the inclusion criteria were selected by non-probability convenience sampling. These patients were divided into 2 groups of 35 patients each, for Oxytocin (Group 1) and misoprostol (Group 2). Main and secondary outcome measures were analysed. SPSS 10 was used for statistical analysis. RESULTS: Average amount of blood loss(ml) was 267.14 +/- 140.35 with Oxytocin versus 302.86 +/- 160.4, with Misoprostol, this difference was statistically insignificant (p = 0.236). Average drop in haemoglobin concentration (g/dl) with Oxytocin was 1.55 +/- 0.38 vs 1.66 +/- 0.61 with Misoprostol (p = 0.684). Drop in haematocrit (%) was 4.18 +/- 0.64 with Oxytocin vs. 4.50 +/- 0.92 with Misoprostol (p = 0.133). There was also insignificant difference in duration of third stage of labour, between oxytocin and Misoprostol groups (5.37 +/- 2.20 vs. 5.23 +/- 2.46, p = 0.451) Shivering, in Misoprostol group occured in n = 11 (31.4%) vs n = 3 (8.6%) with Oxytocin (p = 0.017) and pyrexia in n = 6 (17.1%) with misoprostol vs n = 0, with oxytocin (p = 0.025) thus significantly higher in misoprostol group. CONCLUSION: There were no major differences in oral misoprostol and intramuscular oxytocin in the management of third stage of labour.

Twin births and their complications in women of low socioeconomic profile.

OBJECTIVE: To determine the frequency of twin births and their foetomaternal complications in women of low socioeconomic profile. METHODS: The cross-sectional study was conducted from January 2009 to December 2010 at the Obstetrics and Gynaecolgy Unit I, Civil Hospital, Karachi. Patients with twin pregnancy giving birth beyond 24 weeks, were selected by non-probability purposive sampling. Data on patient characteristics, gestation, antepartum and peripartum complications, chorionicity, mode of delivery and perinatal outcome was recorded and analysed through SPSS 16. RESULTS: Out of 6077 deliveries during the study period, 119 twin births gave a frequency of 19.58/1000 births. Patients' mean age was 27.51+/-4.2 years, mean parity 2.4+/-2.2 and mean gestational age was 34.76+/-3.4 weeks. Unbooked and referred patients were 96 (80.67%). Final paired outcome was alive twin pairs in 74 (62.18%) cases, stillbirth in 7 (5.88%), neonatal deaths in 10 (8.40%). Perinatal mortality rate was 277/1000 twin births. Most frequent foetal complications were low birth weight (n=84; 70.58%), pre-term births (n=70; 58.82%) and intrauterine growth restriction (n=59; 49.57%). The second twin was at significantly higher risk (p< 0.05). Monochorionic twins had significantly high rates of stillbirths than dichorionic (p = 0.023). Most frequent maternal complications comprised pre-term labour (n=56; 47.05%), severe anaemia (n=22; 18.48%), hypertensive disorders (n=19; 15.96%) and postpartum haemorrhage (n=10; 8.40%). CONCLUSION: Twin pregnancies in women of low socioeconomic profile result in very high rates of low birthweight, pre-term births, intrauterine growth restriction, anaemia, hypertensive disorders and postpartum haemorrhage. Monochorionic pregnancies result in high rates of stillbirths and second twin is more likely to be compromised.

Morbidly adherent placenta: can we limit the aftermath?

Morbidly adherent placenta is a grave complication of pregnancy referring to a pathological adherence of placenta to uterine wall with a reported incidence of 1:2500 deliveries. Women with previous two caesarean sections and placenta previa are at greater risk and also those with previous damage to uterine wall. This commentary discusses the pathophysiology, diagnosis and management of the condition in local perspective.