Association between placental mineral deposition, villous architecture and fetal aneuploidy

We retrospectively evaluated the relationship between fetal aneuploidy and placental mineral deposits and villous architecture in 2nd trimester placentas of mid-trimester pregnancy terminations for fetal anomaly. Study cases were aneuploid and matched with euploid controls. Six slides per case were histologically evaluated. Our findings showed significantly increased subtrophoblastic mineral depositions in aneuploidy placentas; also, villous architecture changes between study and control cases were significant for multifocal/extensive villous scalloping and syncytial budding. Our conclusion was that placental histological findings of extensive subtrophoblastic mineral deposition, multifocal/extensive villous scalloping and syncytial budding may suggest aneuploidy.

Substance use among university students at the St Augustine campus of the University of the West Indies

OBJECTIVE

Substance use and abuse is a well known public health risk that peaks in persons between 18 and 25 years of age and is prevalent among university students. While this has been repeatedly documented in developed nations, there have been limited studies in the English-speaking Caribbean. This study therefore sought to assess the prevalence of alcohol, tobacco and marijuana use among university students in the English-speaking Caribbean and any associated risk factors.

METHODS

The study was designed as a descriptive, cross-sectional study to assess substance use in full-time, undergraduate students of The University of the West Indies (UWI), Trinidad and Tobago, over a six-month period. Questionnaires were distributed and students asked to self-report on their use of alcohol, tobacco and marijuana during the preceding six months.

RESULTS

The six-month prevalence rate for alcohol was 70% and 28% of students were identified as regular users. Binge drinking was estimated at 31%. Muslims were least likely to have used alcohol when compared to other religious groupings. The prevalence rate for tobacco and marijuana was 17% and 13%, respectively Ten per cent used all three substances. The use of all three substances was associated with multiple problems.

CONCLUSION

We conclude that substance use is common among many students of the UWI but generally lower than reports from other regions of the world. Despite this, substance use is associated with a number of problems and immediate educational interventions may be necessary to assist students in making informed and responsible choices.

Antenatal management of the expectant mother and extreme preterm infant at the limits of viability

We explored the opinions of healthcare providers on the antenatal management and outcome of preterm delivery at less than 28 weeks gestation. An anonymous postal questionnaire was sent to health care providers. The response rate was 55% (74% Obstetrician, 70% neonatologist). Twenty four weeks is the limit at which most would advocate intervention. At 23 weeks 67% of neonatologists advocate antenatal steroids. 50% of all health care providers advocate cardiotocographic monitoring at 24 weeks gestation. Written information on survival and long-term outcome is provided by 8% of the respondents. Neonatologists (50%) were more likely than obstetrician (40%) to advocate caesarean section at 25 weeks. We conclude that 24 weeks is the limit at which most would advocate intervention. Significant variation exists both between and within each health care group at less than 25 weeks. Establishment and provision of national outcome data may aid decision making at the limits of viability.

Low prevalence of the intact cag pathogenicity island in clinical isolates of Helicobacter pylori in Karachi, Pakistan

Clinical diseases that follow Helicobacter pylori infection are associated with expression of the cagA gene, a part of cytotoxin-associated gene pathogenicity island (cag-PAI). This study aims to determined whether or not the presence of cagA is associated with the presence of complete cag-PAI and to evaluate inflammatory changes associated with the five loci in the cag-PAI of H. pylori comprising cagA, cagA promoter region (cagAP), cagE, cagT and the left end of the cagA gene (LEC). H. pylori isolates were obtained from patients with dyspeptic symptoms. Clinical strains of H. pylori were screened by the polymerase chain reaction (PCR) for respective genes of the cag-PAI. Of 115 H. pylori isolates, 31 (28%) were positive for the five cag-PAI loci. H. pylori isolates with intact cag-PAI were associated with gastric carcinoma (GC; n=9 [60%]) and gastric ulcer (GU; n=5 [45%]) compared to non-ulcer dyspepsia (NUD; n=14 [18%]) (P=0.001 and P=0.049, respectively). In patients with intact cag-PAI, acute on chronic inflammation was present in 25 (81%) and was more common than chronic inflammation (P=0.013). The cagE and cagAP had deletions in 25 (37%) and 23 (35%) cases, respectively. The cagAP region was significantly associated with GC (n=12 [80%], P<0.001) and GU (n=9 [82%], P=0.001) compared to NUD (n=24 [30%] and with significant acute on chronic inflammation (n=40 [80%], P=0.007). The distribution of vacAs1a with intact cag-PAI in GC was 9 (60%) and in NUD was 10 (13%) (P<0.001). The presence of the cagA gene does not signify presence of an intact cag-PAI. Most of the H. pylori isolates studied had partial cag-PAI with missing cagE and cagA promoter regions.

The effect of grain boundaries inside the individual ZnO nanowires in gas sensing

We present the gas sensing characteristics of the individual ZnO nanowires with single-crystalline and multiple grain boundaries (GBs) fabricated using bottom-up and top-down approaches, respectively. The sensor response of the individual ZnO nanowires with the multiple GBs was enhanced approximately three times as compared to that of single-crystalline ZnO nanowires due to well-known GB modulations. However, the response and recovery times of the individual ZnO nanowires with multiple GBs were much slower than those of the single-crystalline ZnO nanowire, indicating the presence of oxygen diffusion resistance to GBs due to the relatively fast surface kinetic reaction. Simplified kinetic diffusion modeling and experimental results could quantify the significant diffusion resistance of gas molecules into the GBs of the individual ZnO nanowires.

Sensitivity-Enhanced CMOS Phase Luminometry System Using Xerogel-Based Sensors

We present the design and implementation of a phase luminometry sensor system with improved and tunable detection sensitivity achieved using a complementary metal-oxide semiconductor (CMOS) integrated circuit. We use sol-gel derived xerogel thin films as an immobilization media to house oxygen (O2) responsive luminescent molecules. The sensor operates on the principal of phase luminometry wherein a sinusoidal modulation signal is used to excite the luminophores encapsulated in the porous xerogel films and the corresponding phase shift of the emission signals is monitored. The phase shift is directly related to excited state lifetimes of the luminophores which in turn are related to the concentration of the target analyte species present in the vicinity of the luminophores. The CMOS IC, which consists of a 16 times 16 high-gain phototransistor array, current-to-voltage converter, amplifier and tunable phase shift detector, consumes an average power of 14 mW with 5-V power supply operating at a 38-kHz modulation frequency. The output of the IC is a dc voltage that corresponds to the detected luminescence phase shift with respect to the excitation signal. As a prototype, we demonstrate an oxygen sensor system by encapsulating the luminophore tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) within the xerogel matrices. The sensor system showed a fast response on the order of few seconds and we obtained a detection sensitivity of 118 mV per 1% change in O2 concentration. The system demonstrates a novel concept to tune and improve the detection sensitivity for specific concentrations of the target analyte in many biomedical monitoring applications.

Polyaniline-cerium oxide nanocomposite for hydrogen peroxide sensor

Hydrogen peroxide (H2O2) sensor has been fabricated by immobilizing horse radish peroxidase (HRP) onto polyaniline(PANI)-cerium oxide (CeO2) nano-composite film onto indium-tin-oxide (ITO) coated glass substrate using electrochemical technique. The HRP/PANI-CeO2/ITO bioelectrode has been characterized using scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy, UV-visible spectroscopy and electrochemical analysis, respectively. This electrode shows improved sensitivity (159.6 nA/mM) and detection limit (50 mM). Further this H2O2 sensor shows high HRP affinity to the PANI-CeO2 matrix as indicated by low value (2.9) mM of Michaelis-Menten constant (K(m)). This bioelectrode exhibits maximum response current at pH 7.0 and retains 90% of its initial response current after about 8 weeks.

Day-case management of hyperemesis gravidarum: Feasibility and clinical efficacy

Day-case management of hyperemesis gravidarum was introduced at the Whipps Cross University Hospital in September 2003. A prospective study of patients managed as day cases between September and December 2003 was undertaken. A total of 27 cases were managed as day cases in accordance with set criteria. All were discharged within 24 h of admission. There were no re-admissions. Patient satisfaction, assessed using a questionnaire, revealed an 88% satisfaction rate. Day-case management of hyperemesis gravidarum should be encouraged. The benefits to the patient are considerable.