Maternal and neonatal colonisation of group B streptococcus at Muhimbili National Hospital in Dar es Salaam, Tanzania: prevalence, risk factors and antimicrobial resistance

Group B streptococcus (GBS), which asymptomatically colonises the vaginal and rectal areas of women, is the leading cause of septicemia, meningitis and pneumonia in neonates. In Tanzania no studies have been done on GBS colonisation of pregnant women and neonates. This study was conducted in Dar es Salaam, Tanzania to determine the prevalence of GBS colonisation among pregnant women, the neonatal colonisation rate and the antimicrobial susceptibility, thus providing essential information to formulate a policy for treatment and prevention regarding perinatal GBS diseases. This cross sectional study involved 300 pregnant women attending antenatal clinic and their newborns delivered at Muhimbili National Hospital (MNH) between October 2008 and March 2009. High vaginal, rectal, nasal, ear and umbilical swabs were cultured on Todd Hewitt Broth and in 5% sheep blood agar followed by identification of isolates using conventional methods and testing for their susceptibility to antimicrobial agents using the Kirby-Bauer method. GBS colonisation was confirmed in 23% of pregnant women and 8.9% of neonates. A higher proportion of GBS were isolated from the vagina (12.3%) as compared to the rectum (5%). Prolonged duration of labour (>12 hrs) was significantly shown to influence GBS colonisation in neonates P < 0.05. Other risk factors such as prolonged rupture of membrane, intrapartum fever, low birth weight and HIV infection did not correlate with GBS colonisation. All isolates were sensitive to vancomycin and ampicillin. Resistance to clindamycin, erythromycin and penicillin G was found to 17.6%, 13% and 9.4%, respectively. Our findings seem to suggest that a quarter of pregnant women attending ANC clinic at MNH and approximately 10% of their newborns are colonised with GBS. All isolates were found to be sensitive to vancomycin and ampicillin which seem to be the most effective antibiotics for the time being. However there is a need for continuous antibiotics surveillance of GBS to monitor trend of resistance. The high isolation frequency of GBS among pregnant women suggests routine antenatal screening at 35 to 37 weeks of gestation in order to provide antibiotic prophylaxis to GBS carrier

Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum

BACKGROUND: Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including horses. Currently, the gold standard protocol for generating dendritic cells from monocytes across various species relies upon a combination of GM-CSF and IL-4 added to cell culture medium which is supplemented with FBS. The aim of this study was to substitute FBS with heterologous horse serum. For this purpose, equine monocyte-derived dendritic cells (eqMoDC) were generated in the presence of horse serum or FBS and analysed for the effect on morphology, phenotype and immunological properties. Changes in the expression of phenotypic markers (CD14, CD86, CD206) were assessed during dendritic cell maturation by flow cytometry. To obtain a more complete picture of the eqMoDC differentiation and assess possible differences between FBS- and horse serum-driven cultures, a transcriptomic microarray analysis was performed. Lastly, immature eqMoDC were primed with a primary antigen (ovalbumin) or a recall antigen (tetanus toxoid) and, after maturation, were co-cultured with freshly isolated autologous CD5+ T lymphocytes to assess their T cell stimulatory capacity. RESULTS: The microarray analysis demonstrated that eqMoDC generated with horse serum were indistinguishable from those generated with FBS. However, eqMoDC incubated with horse serum-supplemented medium exhibited a more characteristic dendritic cell morphology during differentiation from monocytes. A significant increase in cell viability was also observed in eqMoDC cultured with horse serum. Furthermore, eqMoDC generated in the presence of horse serum were found to be superior in their functional T lymphocyte priming capacity and to elicit significantly less non-specific proliferation. CONCLUSIONS: EqMoDC generated with horse serum-supplemented medium showed improved morphological characteristics, higher cell viability and exhibited a more robust performance in the functional T cell assays. Therefore, horse serum was found to be superior to FBS for generating equine monocyte-derived dendritic cells

Structural rearrangements maintain the Glycan Shield of an HIV-1 envelope trimer after the loss of a glycan

The HIV-1 envelope (Env) glycoprotein is the primary target of the humoral immune response and a critical vaccine candidate. However, Env is densely glycosylated and thereby substantially protected from neutralisation. Importantly, glycan N301 shields V3 loop and CD4 binding site epitopes from neutralising antibodies. Here, we use molecular dynamics techniques to evaluate the structural rearrangements that maintain the protective qualities of the glycan shield after the loss of glycan N301. We examined a naturally occurring subtype C isolate and its N301A mutant; the mutant not only remained protected against neutralising antibodies targeting underlying epitopes, but also exhibited an increased resistance to the VRC01 class of broadly neutralising antibodies. Analysis of this mutant revealed several glycans that were responsible, independently or through synergy, for the neutralisation resistance of the mutant. These data provide detailed insight into the glycan shield’s ability to compensate for the loss of a glycan, as well as the cascade of glycan movements on a protomer, starting at the point mutation, that affects the integrity of an antibody epitope located at the edge of the diminishing effect. These results present key, previously overlooked, considerations for HIV-1 Env glycan research and related vaccine studies.IS

Ensiling quality of maize as influenced by the addition of wet distillers grains with soluble

Wet distillers grains with soluble (WDGS) were blended with whole maize plants on an as-fed basis at 0%, 20%, 30%, and 40% and ensiled in 3 L bottles to evaluate the silage fermentation characteristics and ensiling quality in a complete randomized design. Each treatment was ensiled in 15 mini-silos and three bottles were opened on days 7, 21, 42 and 120. Each treatment was sampled for chemical composition and silage fermentation parameters. There was a steady decrease in dry matter (DM) concentration of silage with increasing WDGS inclusion level over time. Initial pH (at day 0) decreased with increasing level of WDGS inclusion, with 40% WDGS inclusion recording the lowest pH (3.6) at day 120. Lactic acid concentration was slightly lower for WDGS-blended silages compared with the control. In contrast, the acetic acid concentration for WDGS-blended silage increased across all treatments, suggesting a possible diminished effect of clostridium bacteria in the silage owing to a reduced pH. The acid detergent fibre (ADF), neutral detergent fibre (NDF) and IVDOM (in vitro digestible organic matter) did not differ at the time of ensiling among treatments. During post ensiling, ADF increased slightly over time for WDGS-blended treatments (at 120 days). The results from this study indicated that WDGS could be ensiled effectively with maize plants without compromising silage quality.Keywords: Acetic acid, butyric acid, fermentation, lactic acid, preservation, silag

Spinal shape modulation in a porcine model by a highly flexible and extendable non-fusion implant system

Purpose: In vivo evaluation of scoliosis treatment using a novel approach in which two posterior implants are implanted: XSLAT (eXtendable implant correcting Scoliosis in LAT bending) and XSTOR (eXtendable implant correcting Scoliosis in TORsion). The highly flexible and extendable implants use only small, but continuous lateral forces (XSLAT) and torques (XSTOR), thereby allowing growth and preventing fusion. Methods: Since (idiopathic) scoliosis does not occur spontaneously in animals, the device was used to induce a spinal deformity rather than correct it. Six of each implants were tested for their ability to induce scoliotic deformations in 12 growing pigs. Each implant spanned six segments and was attached to three vertebrae using sliding anchors. Radiological and histological assessments were done throughout the 8-week study. Results: In all animals, the intended deformation was accomplished. Average Cobb angles were 19° for XSLAT and 6° for XSTOR. Average apical spinal torsion was 0° for XSLAT and 9° for XSTOR. All instrumented segments remained mobile and showed 20 % growth. Moderate degeneration of the facet joints was observed and some debris was found in the surrounding tissue. Conclusions: The approach accomplished the intended spinal deformation while allowing growth and preventing fusion

A reliability and validity study for different coronal angles using ultrasound imaging in adolescent idiopathic scoliosis

Background Context: Radiation exposure remains a big concern in adolescent idiopathic scoliosis (AIS). Ultrasound imaging of the spine could significantly reduce or possibly even eliminate this radiation hazard. The spinous processes (SPs) and transverse processes (TPs) were used to measure the coronal deformity. Both landmarks provided reliable information on the severity of the curve as related to the traditional Cobb angle. However, it remained unclear which coronal ultrasound angle is the most appropriate method to measure the curve severity. Purpose: The objective of this study was to test the reliability and the validity of several ultrasound angle measurements in the coronal plane as compared with the radiographic coronal Cobb angle in patients with AIS. Study Design/Setting: This is a cross-sectional study. Patient Sample: The study included 33 patients with AIS, both male and female (Cobb angle range: 3°-90°, primary and secondary curves), who underwent posterior-anterior radiography of the spine. Outcome Measures: The outcome measures were the reliability (intraclass correlation coefficients [ICCs] for the intra- and interobserver variabilities) and the validity (linear regression analysis and Bland-Altman method, including the mean absolute difference [MAD]) of different ultrasound measurements. Materials and Methods: The patients were scanned using a dedicated ultrasound machine (Scolioscan, Telefield Medical Imaging Ltd, Hong Kong). The reliability and the validity were tested for three coronal ultrasound angles: an automatic and manual SP angle and a manual TP angle as compared with the radiographic coronal main thoracic or (thoraco)lumbar Cobb angles. Results: The ICC showed very reliable measurements of all ultrasound methods (ICC ≥0.84). The ultrasound angles were 15%-37% smaller as compared with the Cobb angles; however, excellent linear correlations were seen between all ultrasound angles and the Cobb angle (thoracic: R 2≥0.987 and (thoraco)lumbar R 2≥0.970), and the Bland-Altman plot showed a good agreement between all ultrasound angles and the Cobb angle. The MADs of the ultrasound angles, corrected using the linear regression equation, and the Cobb angles showed no significant difference between the different ultrasound angles (MAD: automatic SP angle 4.9°±3.2°, manual SP angle 4.5°±3.1°, and manual TP angle 4.7°±3.6°; p≥.388). Conclusions: Coronal ultrasound angles are based on different landmarks than the traditional Cobb angle measurement and cannot represent the same angle values. In this study, we found excellent correlations between the ultrasound and Cobb measurements, without differences in the reliability and validity between the ultrasound angles based on the SPs and TPs. Therefore, the severity of the deformity in patients with AIS can be assessed by ultrasound imaging, avoiding hazardous ionizing radiation and enabling more individualized patient care. It also opens possibilities for screening

Anterior Spinal Overgrowth is the Result of the Scoliotic Mechanism and is Located in the Disc

STUDY DESIGN: Cross-sectional. OBJECTIVE: To investigate the presence and magnitude of anterior spinal overgrowth in neuromuscular scoliosis and compare this to the same measurements in idiopathic scoliosis and healthy spines. SUMMARY OF BACKGROUND DATA: Anterior spinal overgrowth has been described as a potential driver for the onset and progression of adolescent idiopathic scoliosis (AIS). Whether this anterior overgrowth is specific for AIS or also present in non-idiopathic scoliosis has not been reported. METHODS: Supine CT scans of thirty AIS patients (thoracic Cobb 21-81°), thirty neuromuscular (NM) scoliotic patients (thoracic Cobb 19-101°) and thirty non-scoliotic controls were used. The difference in length in per cents between the anterior and posterior side (((ΔA-P)/P)*100%, abbreviated to A-P%) of each vertebral body and intervertebral disc, and between the anterior side of the spine and the spinal canal (A-C%) were determined. RESULTS: The A-P% of the thoracic curves did not differ between the AIS (+1.2 ± 2.2%) and NM patients (+0.9 ± 4.1%, P = 0.663), both did differ, however, from the same measurements in controls (-3.0 ± 1.6%; P < 0.001) and correlated linearly with the Cobb angle (AIS r = 0.678, NM r = 0.687). Additional anterior length was caused by anterior elongation of the discs (AIS: A-P% disc +17.5 ± 12.7% versus A-P% body -2.5 ± 2.6%; P < 0.001, NM: A-P% disc +19.1 ± 18.0% versus A-P% body -3.5 ± 5.1%; P < 0.001). The A-C% T1-S1 in AIS and NM patients were similar (+7.9 ± 1.8% and +8.7 ± 4.0%, P = 0.273), but differed from the controls (+4.2 ± 3.3%; P < 0.001). CONCLUSIONS: So called anterior overgrowth has been postulated as a possible cause for idiopathic scoliosis, but apparently it occurs in scoliosis with a known origin as well. This suggests that it is part of a more generalized scoliotic mechanism, rather than its cause. The fact that the intervertebral discs contribute more to this increased anterior length than the vertebral bodies suggests an adaptation to altered loading, rather than a primary growth disturbance

Anterior Spinal Overgrowth is the Result of the Scoliotic Mechanism and is Located in the Disc

STUDY DESIGN: Cross-sectional. OBJECTIVE: To investigate the presence and magnitude of anterior spinal overgrowth in neuromuscular scoliosis and compare this to the same measurements in idiopathic scoliosis and healthy spines. SUMMARY OF BACKGROUND DATA: Anterior spinal overgrowth has been described as a potential driver for the onset and progression of adolescent idiopathic scoliosis (AIS). Whether this anterior overgrowth is specific for AIS or also present in non-idiopathic scoliosis has not been reported. METHODS: Supine CT scans of thirty AIS patients (thoracic Cobb 21-81°), thirty neuromuscular (NM) scoliotic patients (thoracic Cobb 19-101°) and thirty non-scoliotic controls were used. The difference in length in per cents between the anterior and posterior side (((ΔA-P)/P)*100%, abbreviated to A-P%) of each vertebral body and intervertebral disc, and between the anterior side of the spine and the spinal canal (A-C%) were determined. RESULTS: The A-P% of the thoracic curves did not differ between the AIS (+1.2 ± 2.2%) and NM patients (+0.9 ± 4.1%, P = 0.663), both did differ, however, from the same measurements in controls (-3.0 ± 1.6%; P < 0.001) and correlated linearly with the Cobb angle (AIS r = 0.678, NM r = 0.687). Additional anterior length was caused by anterior elongation of the discs (AIS: A-P% disc +17.5 ± 12.7% versus A-P% body -2.5 ± 2.6%; P < 0.001, NM: A-P% disc +19.1 ± 18.0% versus A-P% body -3.5 ± 5.1%; P < 0.001). The A-C% T1-S1 in AIS and NM patients were similar (+7.9 ± 1.8% and +8.7 ± 4.0%, P = 0.273), but differed from the controls (+4.2 ± 3.3%; P < 0.001). CONCLUSIONS: So called anterior overgrowth has been postulated as a possible cause for idiopathic scoliosis, but apparently it occurs in scoliosis with a known origin as well. This suggests that it is part of a more generalized scoliotic mechanism, rather than its cause. The fact that the intervertebral discs contribute more to this increased anterior length than the vertebral bodies suggests an adaptation to altered loading, rather than a primary growth disturbance

What is the Actual 3D Representation of the Rib Vertebra Angle Difference (Mehta Angle)?

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To establish the relevance of the conventional two-dimensional (2D) RVAD and the relationship with the complex three-dimensional (3D) apical morphology in scoliosis. SUMMARY OF BACKGROUND DATA: The rib vertebra angle difference (RVAD, also known as Mehta's angle) describes apical rib asymmetry on conventional radiographs and was introduced as a prognostic factor for curve severity in early onset scoliosis, and later applied to other types of scoliosis as well. METHODS: An existing idiopathic scoliosis database of high-resolution CT scans used in previous work, acquired for spinal navigation, was used. Eighty-eight patients (Cobb angle 46-109°) were included. Cobb angle and 2D RVAD, as described by Mehta, were measured on the conventional radiographs and coronal digitally reconstructed radiographs (DRR) of the prone CT scans. A previously validated, semi-automatic image processing technique was used to acquire complete 3D spinal reconstructions for measurement of the 3D RVAD in a reconstructed true coronal plane, axial rotation and sagittal morphology. RESULTS: The 2D RVAD on the X-ray was on average 25.3 ± 11.0° and 25.6 ± 12.8° on the DRR (P = 0.990), but in the true 3D coronal view of the apex, hardly any asymmetry remained (3D RVAD: 3.1 ± 12.5°; 2D RVAD on X-ray and DRR versus 3D RVAD: P < 0.001). 2D apical rib asymmetry in the anatomical coronal plane did not correlate with the same RVAD measurements in the 3D reconstructed coronal plane of the rotated apex (r = 0.155; P = 0.149). A larger 2D RVAD was found to correlate linearly with increased axial rotation (r = 0.542; P < 0.001) and apical lordosis (r = 0.522; P < 0.001). CONCLUSIONS: The 2D RVAD represents a projection-based composite radiographic index reflecting the severity of the complex 3D apical morphology including axial rotation and apical lordosis. It indicates a difference in severity of the apical deformation. LEVEL OF EVIDENCE: 4