Development of a 3D Brain Model to Study Sex-Specific Neuroinflammation After Hemorrhagic Stroke

Subarachnoid hemorrhage (SAH) accounts for 5% of stroke, with women having a decreased inflammatory response compared to men; however, this mechanism has yet to be identified. One hurdle in SAH research is the lack of human brain models. Studies in murine models are helpful, but human models should be used in conjunction for improved translatability. These observations lead us to develop a 3D system to study the sex-specific microglial and neuroglial function in a novel in vitro human SAH model and compare it to our validated in vivo SAH model. Our lab has developed a 3D, membrane-based in vitro cell culture system with human astrocytes, microglia, and neurons from both sexes. The 3D cultures were incubated with male and female cerebrospinal fluid from SAH patients in the Neuro-ICU. Furthermore, microglial morphology, erythrophagocytosis, microglial inflammatory cytokine production, and neuronal apoptosis were studied and compared with our murine SAH models. The human 3D system demonstrated intercellular interactions and proportions of the three cell types similar to the adult human brain. In vitro and in vivo models of SAH showed concordance in male microglia being more inflammatory than females via morphology and flow cytometry. On the contrary, both in vitro and in vivo models revealed that female microglia were more phagocytic and less prone to damaging neurons than males. One possible explanation for the increased phagocytic ability of female microglia was the increased expression of CD206 and MerTK. Our in vitro, human, 3D cell culture SAH model showed similar results to our in vivo murine SAH model with respect to microglial morphology, inflammation, and phagocytosis when comparing the sexes. A human 3D brain model of SAH may be a useful adjunct to murine models to improve translation to SAH patients.

Aflibercept monotherapy versus aflibercept with targeted retinal laser to peripheral retinal ischemia for diabetic macular oedema (LADAMO)

OBJECTIVE

We tested the hypothesis that targeted retinal laser photocoagulation (TPRP) to peripheral retinal ischaemia reduces the overall burden of aflibercept injections when treating diabetic macular oedema (DMO) over a 24-month period.

METHODS

Prospective, double-masked, multicentre, randomised controlled trial in Australia comparing aflibercept monotherapy, following a treat-and-extend protocol, or combination therapy of aflibercept and TPRP for DMO. The aflibercept monotherapy group received placebo laser. The primary outcome measure was the mean number of intravitreal aflibercept injections for each group at 24 months. Secondary outcome included: mean change in central macular thickness (CMT) and vision at trial completion, the proportion of eyes whose DMO resolved and the mean injection treatment interval. Ocular and systemic adverse events were recorded.

RESULTS

We enrolled 48 eyes of 47 patients; 27 eyes were randomised to combination therapy (aflibercept and TPRP) and 21 to aflibercept monotherapy. Thirty-two eyes (67%) completed the 2-year study. The number of intravitreal treatments given were similar for combination therapy (10.5 (SD 5.8) and monotherapy (11.8 (SD5.6)) (P = 0.44). The mean visual improvement (+4.0 (-1.8, 9.8) and +7.8 (2.6, 12.9) letters, P = 0.32), mean decrease in CMT (-154 (-222,-87) µm and -152 (-218,-86) µm, P = 0.96), proportion of eyes with CMT < 300 µm (48% and 67%; P = 0.50) and safety outcomes were similar in both the combination and monotherapy treatment groups (respectively).

CONCLUSIONS

Laser to areas of ischaemic peripheral retina does not reduce the burden of intravitreal aflibercept injections when treating diabetic macular oedema.

Intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction

Calorie restriction can enhance the regenerative capacity of the injured intestinal epithelium. Among other metabolic changes, calorie restriction can activate the autophagy pathway. Although independent studies have attributed the regenerative benefit of calorie restriction to downregulation of mTORC1, it is not known whether autophagy itself is required for the regenerative benefit of calorie restriction. We used mouse and organoid models with autophagy gene deletion to evaluate the contribution of autophagy to intestinal epithelial regeneration following calorie restriction. In the absence of injury, mice with intestinal epithelial-specific deletion of autophagy gene Atg7 (Atg7ΔIEC) exhibit weight loss and histological changes similar to wild-type mice following calorie restriction. Conversely, calorie-restricted Atg7ΔIEC mice displayed a significant reduction in regenerative crypt foci after irradiation compared with calorie-restricted wild-type mice. Targeted analyses of tissue metabolites in calorie-restricted mice revealed an association between calorie restriction and reduced glycocholic acid (GCA) in wild-type mice but not in Atg7ΔIEC mice. To evaluate whether GCA can directly modulate epithelial stem cell self-renewal, we performed enteroid formation assays with or without GCA. Wild-type enteroids exhibited reduced enteroid formation efficiency in response to GCA treatment, suggesting that reduced availability of GCA during calorie restriction may be one mechanism by which calorie restriction favors epithelial regeneration in a manner dependent upon epithelial autophagy. Taken together, our data support the premise that intestinal epithelial Atg7 is required for the regenerative benefit of calorie restriction, due in part to its role in modulating luminal GCA with direct effects on epithelial stem cell self-renewal.NEW & NOTEWORTHY Calorie restriction is associated with enhanced intestinal regeneration after irradiation, but the requirement of autophagy for this process is not known. Our data support the premise that intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction. We also report that luminal levels of primary bile acid glycocholic acid are modulated by epithelial cell autophagy during calorie restriction with direct effects on epithelial stem cell function.

Distribution of soil carbon fractions under different bamboo species in northwest Himalayan foothills, India

Soil carbon and its fractions are important in understanding the mechanism of soil carbon sequestration. The present study evaluated the impact of seven commercial bamboo species, viz., Bambusa balcooa, B. bambos, B. vulgaris, B. nutans, Dendrocalamus hamiltonii, D. stocksii, and D. strictus, on labile and non-labile carbon fractions. In the 0-15-cm layer, B. nutans had the highest very labile C (7.65 g kg^-1) followed by B. vulgaris > B. balcooa > D. stocksii > D. hamiltonii > B. bambos > D. strictus > open. The active carbon pool was significantly low under the control plot (i.e. the open) indicating the positive influence of bamboo in soil C build-up in the top 0-15 cm soil layer. Amongst the different species of bamboo evaluated in this study, D. strictus accumulated the highest active C pool in 0-30-cm soil layer followed by B. vulgaris. Of the total organic C in the 0-30 cm soil depth, majority (55-60%) was contributed by the passive C pool comprising the less labile and the non-labile fraction of SOC. A high value of carbon stratification ratio (> 2) was observed for D. strictus, B. bambos, and D. hamiltonii which proves their potential for restoration of the degraded lands. The majority of bamboo species except for B. balcooa and D. stocksii showed a higher carbon management index than open systems, thereby indicating higher rates of soil C rehabilitation. Of the seven bamboo species, B. vulgaris, D. strictus, and B. nutans can be adopted for cultivation in the northwest Himalayas given their ability to positively impact the SOC and its fractions in both surface and sub-surface soil.

In hospital outcomes of orbital/rotational coronary atherectomy in diabetic vs non-diabetic population: insights from the nationwide inpatient sample

Background

Atherectomy (AT) using an orbital/rotational system is useful in altering calcified plaque thereby facilitating stent placement and optimal stent expansion. Patients with diabetes mellitus (DM) are known to have a higher rate of complications after percutaneous coronary intervention. We aimed to assess the incidence of major adverse cardiovascular events after atherectomy in the diabetic population using a nationwide inpatient sample (NIS).

Methods

NIS-HCUP database from 2015–2017 was used to identify patients who underwent atherectomy. A cohort of patients with and without diabetes was identified. Demographics, in-hospital outcomes, complications in both groups were compared. Statistical significance was assigned at p&lt;0.05.

Results

Out of 6184 patients who underwent AT, 3134 (50.6%) patients had DM. Baseline characteristics have been outlined in the table below. Complications were comparable between the two groups except for higher incidence of post-procedure VTE in Diabetic patients. In-hospital mortality was lower among patients with DM (2.24% vs 3.29%, p-0.27), while the mean length of stay (5.92 vs 4.91 days, p-0.002) and the hospitalization charges ($165118.4 vs 151226, p-0.04) were higher, but this difference in length of stay and hospitalization charges were nullified on multivariate regression.

Conclusion

Our study suggests that an AT for severely calcified plaque in the coronary artery is a safe option in patients with DM with comparable in-hospital complications and outcomes to non-DM patients.

Funding Acknowledgement

Type of funding sources: None. Demographics and Outcomes of Atherectomy

Assessment of eco-hydrological parameters for important sympodial bamboo species in Himalayan foothills

Bamboos due to high soil water conservation potential are gaining increased attention in plantation programs across the globe. Large-scale plantation of fast-growing bamboo, however, can have important hydrological consequences. The study aims to quantify the eco-hydrological parameters, viz., throughfall (TF), stemflow (SF), and interception (I) in seven important sympodial bamboo species in north western Himalayan foothills of India. The species selected include Bambusa balcooa, Bambusa bambos, Bambusa vulgaris., Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii, and Dendrocalamus strictus. Throughfall versus gross rainfall (GR) relationship in different species indicated high throughfall production during high rainfall events with r² > 0.90. Average throughfall was lowest (62.1%) in D. hamiltonii and highest in B. vulgaris (74.6%). SF ranged from 1.32% in B. nutans to 3.39% in D. hamiltonii. The correlation coefficient (r) between leaf area index (LAI), number of culms, and crown area with the interception were 0.746, 0.691, and 0.585, respectively. The funneling ratio (F) was highest (27.0) in D. hamiltonii and least in B. nutans. Canopy storage capacity was highest in D. strictus (3.57 mm) and least in D. hamiltonii (1.09 mm). Interception loss was highest (34.4%) in D. hamiltonii and lowest in B. vulgaris (23.5%) and D. strictus (23.6%). Higher interception in bamboos make them suitable for soil conservation, but careful selection of species is required in low rainfall areas.

Vessel Wall Enhancement and Focal Cerebral Arteriopathy in a Pediatric Patient with Acute Infarct and COVID-19 Infection

Herein, we report the findings of intracranial arterial wall enhancement, consistent with focal cerebral arteriopathy-inflammatory type, in a child presenting with acute infarct in the setting of coronavirus disease 2019 (COVID-19) infection. To our knowledge, this report provides the first description of vessel wall imaging findings in COVID-19-associated acute stroke.

Outcomes of transcatheter mitral valve repair from the latest nationwide inpatient sample database 2016–2017

Background

Transcatheter mitral valve repair (TMVR) is an alternative treatment option for severe mitral regurgitation (severe MR) in patients with high surgical risk. Previous studies have demonstrated safety and efficacy of TMVR. The aim of our study was to assess comorbid and patient outcome data in a nationwide sample.

Methods

From the Nationwide Inpatient Sample (NIS) 2016–2017, all adult patients with mitral valve regurgitation were identified. Patients were divided into two group- TMVR and SMVR (surgical mitral valve repair). Patients requiring surgical valve replacement were excluded. Primary outcomes were inpatient mortality and length of stay. Multivariate analysis was performed to adjust for comorbidities.

Results

A total of 6211 TMVR were performed, while 3789 SMVR were performed. TMVR patients were older (78.34 vs 62.26 years) and had more females (48.86 vs 36.18%). Comorbidities were higher in the TMVR group [heart failure (81.02 vs 46.02%, p&lt;0.001), diabetes mellitus (27.13 vs 15.81%, p&lt;0.001), chronic kidney disease (39.3 vs 13.7%, p&lt;0.001), chronic lung disease (27.13 vs 16.65%, p&lt;0.001). Complications were higher in the SMVR [Cardiogenic shock (3.8 vs 6%, p=0.007), blood transfusion requirement (19.44 vs 4.85%, p=0.001), respiratory failure (10.99 vs 7.37, p=0.012)]. Mean length of stay was higher with SMVR [8.60±0.22 (4.139–5.17) days] compared to TMVR [4.65±0.26 (8.167–9.03) days]. In-patient mortality was lower in TMVR (2.01 vs 2.45%, p-0.02). After adjusting for comorbidities on multivariate analysis, there was no difference in mortality between the groups (adjusted OR=1.081±0.419 (0.506–2.311).

Conclusion

From nationwide data, we report TMVR as a relatively safe treatment modality for severe MR, with comparable inpatient mortality and fewer complications than SMVR, despite having a significantly higher burden of comorbidities.

Funding Acknowledgement

Type of funding source: None

MRI Brain Findings in 126 Patients with COVID-19: Initial Observations from a Descriptive Literature Review

BACKGROUND AND PURPOSE

Recently, numerous investigational studies, case series, and case reports have been published describing various MR imaging brain findings in patients with COVID-19. The purpose of this literature review was to compile and analyze brain MR imaging findings in patients with COVID-19-related illness.

MATERIALS AND METHODS

Literature searches of PubMed, publicly available Internet search engines, and medical journal Web sites were performed to identify articles published before May 30, 2020 that described MR imaging brain findings in patients with COVID-19.

RESULTS

Twenty-two articles were included in the analysis: 5 investigational studies, 6 case series, and 11 case reports, encompassing MR imaging of the brain in 126 patients. The articles originated from 7 different countries and were published in 14 medical journals. MR imaging brain findings included specific diagnoses (such as acute infarct, posterior reversible encephalopathy syndrome) or specific imaging features (such as cortical FLAIR signal abnormality, microhemorrhages).

CONCLUSIONS

The most frequent diagnoses made on brain MR imaging in patients with COVID-19 were acute and subacute infarcts. Other common findings included a constellation of leukoencephalopathy and microhemorrhages, leptomeningeal contrast enhancement, and cortical FLAIR signal abnormality.

Rooting behaviour and soil properties in different bamboo species of Western Himalayan Foothills, India

Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m⁻³ in B. nutans to 2.0 kg m⁻³ in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m⁻³ in B. nutans to 4.5 kg m⁻³ in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha⁻¹ in D. stocksii to 12.4 Mg ha⁻¹ in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion.

A Retrospective Study of Administrative Data to Identify Factors Associated with Future Disability Status among Older Colorectal Cancer Survivors

Disability is associated with loss of independence and early mortality. Currently, only 1–2% of cancer survivors who reported physical limitations received rehabilitation services. It is critical to identify factors associated with the development of disability to guide clinical practice given treatment changes. We aimed to 1) identify demographic and cancer-related characteristics associated with future disability status among older colorectal cancer survivors, and 2) compared the future disability status among cancer and matched non-cancer cohorts. Methods: We conducted a retrospective cohort study using the Texas Cancer Registry-national Medicare linked database. The cancer cohort included Medicare beneficiaries with a primary colorectal cancer diagnosis between 2005 and 2013 (n = 13,229). The non-cancer cohort was identified from a 5% sample of Medicare beneficiaries (n = 11,416). Diagnosis dates from the cancer cohort were used as the index date for the non-cancer cohort. Cohorts were matched 1:1 based on index date, age, and gender. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals. Disability status was defined according to Davidoff and colleagues using inpatient, outpatient and durable medical equipment claims files, and assessed monthly, beginning 1 month after cancer diagnosis (or index date), continuing until disability, death, end of Medicare continuous enrollment, or end of study. Results: Factors that were significantly associated with disability status in the cancer cohort were age (HR = 3.50 for &gt;80 years old), female gender (HR = 1.50), race/ethnicity (HR = 1.34 for Hispanic and 1.21 for Black), stage (HR = 2.26 for distant stage), comorbidity (HR = 2.18 for &gt;1), and radiation (HR = 1.21). When compared to the non-cancer cohort, having a cancer diagnosis (HR = 1.07) and comorbidity (HR = 2.09 for &gt;1) were associated with developing disability. Conclusions: Colorectal diagnosis is an independent risk for disability status. Beyond well-known risk factors “age and mortality” subsets of survivors (Hispanic and Black survivors and those with comorbidity) are found to be at higher risk for developing disability. This warrants further investigation and may indicate targeted intervention to prevent future disability.

Minimizing Radiation Exposure in Evaluation of Pediatric Head Trauma: Use of Rapid MR Imaging

BACKGROUND AND PURPOSE

With >473,000 annual emergency department visits for children with traumatic brain injuries in the United States, the risk of ionizing radiation exposure during CT examinations is a real concern. The purpose of this study was to assess the validity of rapid MR imaging to replace CT in the follow-up imaging of patients with head trauma.

MATERIALS AND METHODS

A retrospective review of 103 pediatric patients who underwent initial head CT and subsequent follow-up rapid MR imaging between January 2010 and July 2013 was performed. Patients had minor head injuries (Glasgow Coma Scale, >13) that required imaging. Initial head CT was performed, with follow-up rapid MR imaging completed within 48 hours. A board-certified neuroradiologist, blinded to patient information and scan parameters, then independently interpreted the randomized cases.

RESULTS

There was almost perfect agreement in the ability to detect extra-axial hemorrhage on rapid MR imaging and CT (κ = 0.84, P < .001). Evaluation of hemorrhagic contusion/intraparenchymal hemorrhage demonstrated a moderate level of agreement between MR imaging and CT (κ = 0.61, P < .001). The ability of MR imaging to detect a skull fracture also showed a substantial level of agreement with CT (κ = 0.71, P < .001). Detection of diffuse axonal injury demonstrated a slight level of agreement between MR imaging and CT (κ = 0.154, P = .04). However, the overall predictive agreement for the detection of an axonal injury was 91%.

CONCLUSIONS

Rapid MR imaging is a valid technique for detecting traumatic cranial injuries and an adequate examination for follow-up imaging in lieu of repeat CT.

Structural changes of the choroid in sarcoid- and tuberculosis-related granulomatous uveitis

AIM

The aim of this study is to characterise the choroidal features of patients diagnosed with sarcoid- and tuberculosis (TB)-associated granulomatous uveitis using spectral domain optical coherence tomography (OCT).

METHODS

Twenty-seven patients (27 eyes) diagnosed with sarcoid- (13 eyes) and TB (14 eyes)-related uveitis were included in this retrospective, cross-sectional study. Over a six-month period, patients diagnosed with sarcoid and TB granulomatous uveitis were scanned using enhanced depth imaging OCT. Clinical and demographical characteristics were recorded, including the method of diagnosis, disease activity, site of inflammation (anterior or posterior), treatments, and visual acuity (VA). Manual segmentation of the choroidal layers was performed using custom image analysis software.

RESULTS

The main outcome measure was OCT-derived thickness measurements of the choroid and choroidal sublayers (Haller's large vessel and Sattler's medium vessel layers) at the macula region. The ratio of Haller's large vessel to Sattler's medium vessel layer was significantly different at the total macula circle in eyes diagnosed with TB uveitis (1.47 (=140.71/95.72 μm)) compared with sarcoid uveitis (1.07 (=137.70/128.69 μm)) (P=0.001). A thinner choroid was observed in eyes with a VA ≥0.3 LogMAR (Snellen 6/12; 198.1 μm (interquartile range (IQR)=147.0-253.4 μm) compared with those with VA <0.3 LogMAR (292.4 μm (IQR=240.1-347.6 μm)) at the total macula circle (P=0.004). At the foveal central subfield, the median choroidal thickness was 336.8 μm (IQR=272.3-375.4 μm) in active compared with 239.3 μm (IQR=195.3-330.9 μm) in quiescent disease (P=0.04).

CONCLUSION

A disproportionately enlarged Sattler's layer may indicate a diagnosis of sarcoid-related uveitis, and choroidal thickening may be a feature of active granulomatous uveitis.

Observation and quantification of nanoscale processes in lithium batteries by operando electrochemical (S)TEM

An operando electrochemical stage for the transmission electron microscope has been configured to form a "Li battery" that is used to quantify the electrochemical processes that occur at the anode during charge/discharge cycling. Of particular importance for these observations is the identification of an image contrast reversal that originates from solid Li being less dense than the surrounding liquid electrolyte and electrode surface. This contrast allows Li to be identified from Li-containing compounds that make up the solid-electrolyte interphase (SEI) layer. By correlating images showing the sequence of Li electrodeposition and the evolution of the SEI layer with simultaneously acquired and calibrated cyclic voltammograms, electrodeposition, and electrolyte breakdown processes can be quantified directly on the nanoscale. This approach opens up intriguing new possibilities to rapidly visualize and test the electrochemical performance of a wide range of electrode/electrolyte combinations for next generation battery systems.

Vibration platform for mice to deliver precise, low intensity mechanical signals to the musculoskeleton

OBJECTIVE

Low intensity vibration as a therapeutic and training modality has received increased attention despite the lack of clear mechanistic pathways. Thus, to determine mechanisms underpinning vibration-induced musculoskeletal adaptations, a vibration platform for mice was designed, constructed, and validated.

METHODS

Critical aspects of the platform include use of off-the-shelf components to (1) tailor individual parameter selection (acceleration and frequency), (2) produce low error across the plate's surface and throughout the range of vibration parameters, and (3) utilize accelerometer feedback to ensure fidelity within and between bouts of vibration. The vibration device is controlled by a centrally-mounted linear actuator on the underside of the platform that is modulated by accelerometer feedback.

RESULTS

Triaxial accelerometers confirmed that vibrations were purely vertical and acceleration responses were within 5% of target stimuli for all accelerations (0.2-1.0 g) and frequencies (25-90 Hz). The platform produced acceleration responses with ≤4% error between 25-90 Hz. Vibration modes were not detected indicating that the circular plate produced uniform stimuli across the platform (error ≤1.1%, P≥0.23) and mouse body mass did not affect the platform's performance (P≥0.43).

CONCLUSIONS

Our vibration device for mice improves upon existing devices and enables precise, low intensity mechanical signals to be applied with confidence.

Biomechanical analysis of pedicle screw thread differential design in an osteoporotic cadaver model

BACKGROUND

Pedicle screw fixation, the standard surgical care for posterior stabilization in the thoraco-lumbar spine has a high rate of failure in osteoporotic individuals. Screw design factors and insertion techniques have been shown to influence the biomechanical performance of pedicle screws. Our objective was to investigate the biomechanical characteristics of pedicle screw fixation in osteoporotic bone by comparing standard screws with newly designed differential crest thickness dual lead screws.

METHODS

An in-vitro spinal-level paired factorial study design was used to examine thoraco-lumbar spine biomechanical outcomes for differential pedicle screw thread designs. Six cadaveric human spines (T8-L5) were tested for six groups (n=20) consisting of 2 different crest thickness and 3 different insertion techniques. Bone mineral density was assessed and peak insertion torque measured while placing one screw of new design and control on the contralateral side. Screw pullout properties were measured from classical American Society for Testing and Materials protocols.

FINDINGS

The screws designed specifically for osteoporotic bone showed significantly larger insertion torque compared with the standard screw design irrespective of insertion technique. Much of the variability in pullout failure and stiffness was explained by bone mineral density. The osteoporotic screws of different crest thickness were statistically similar to each other in all outcome measures.

INTERPRETATION

Compared with standard pedicle screws, the dual lead osteoporotic-specific pedicle screws demonstrated significantly larger insertion torques and similar pullout properties. Non-significant increased biomechanical strength was observed for thin crest compared to thick crest dual lead pedicle screws indicating their enhanced purchase in osteoporotic bone.

Skeletal muscle MRI magnetisation transfer ratio reflects clinical severity in peripheral neuropathies

MRI may provide treatment outcome measures in neuromuscular conditions. The authors assessed MRI magnetisation transfer ratios (MTRs) in lower-limb musculature as markers of pathology in peripheral neuropathies and compared the findings with associated clinical data. Ten patients with Charcot-Marie-Tooth disease type 1A (CMT1A) and nine patients with chronic inflammatory demyelinating polyneuropathy (CIDP) were compared with 10 healthy subjects. The MTR in the calf muscles was significantly lower than controls in the two patient groups (both p<0.001). The median MTRs (IQR) were 50.5(1.6) percentage units (p.u.) (control), 41.5(10.6) p.u. (CMT1A) and 39.3(8.7) p.u. (CIDP). Moreover, anterior lower leg MTR correlated strongly with strength of ankle dorsiflexion, measured with the Medical Research Council scale, in CIDP (ρ=0.88, p<0.001) and also in CMT1A (ρ=0.50, p<0.05), where MTR also showed an association with disease duration (ρ=-0.86, p<0.001). Short tau inversion recovery MRI of the same muscles showed abnormalities associated with regions of reduced MTR (p<0.001), and MTR was also reduced in other muscles otherwise deemed normal appearing (p<0.001), indicating that MTR may be more sensitive to muscle damaged by denervation than conventional MRI. The significant reductions in muscle MTR in peripheral neuropathies and the associated correlations with clinical measures indicate that MTR has potential as an imaging outcome measure in future therapeutic trials.

MRI shows increased sciatic nerve cross sectional area in inherited and inflammatory neuropathies

Measurements of the cross sectional area of the sciatic nerve are described in a group of 10 patients with genetically confirmed Charcot-Marie-Tooth disease type 1A (CMT1A), nine patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 10 healthy controls using MRI. One mid-thigh of each individual was imaged using a short tau inversion recovery sequence and the nerve appearance evaluated radiologically with respect to the signal intensity and visibility of the internal neural structure. The cross sectional area of the sciatic nerve of each individual was measured by defining irregular enclosing regions of interest on the MRI images. The sciatic nerve area was enlarged in both CMT1A (p<0.001) and CIDP (p=0.008) compared with controls and in CMT1A compared with CIDP (p<0.001). Median (interquartile range) areas were 67.6 (16.2) mm(2) for the CIDP group, 135.9 (46.5) mm(2) for the CMT1A group and 43.3 (19.9) mm(2) for the control group. The critical upper value for discriminating pathologically enlarged nerves from normal controls with p<0.05 was 64.4 mm(2). Quantification of sciatic nerve hypertrophy on MRI may be of assistance in cases where the diagnosis is still in doubt, providing an objective pathological marker complimenting other clinical investigations.

Cytoplasmic polyadenylation element binding protein is a conserved target of tumor suppressor HRPT2/CDC73

Parafibromin, a tumor suppressor protein encoded by HRPT2/CDC73 and implicated in parathyroid cancer and the hyperparathyroidism-jaw tumor (HPT-JT) familial cancer syndrome, is part of the PAF1 transcriptional regulatory complex. Parafibromin has been implicated in apoptosis and growth arrest, but the mechanism by which its loss of function promotes neoplasia is poorly understood. In this study we report that a hypomorphic allele of hyrax (hyx), the Drosophila homolog of HRPT2/CDC73, rescues the loss-of-ventral-eye phenotype of lobe (Akt1s1). Such rescue is consistent with previous reports that hyx/parafibromin is required for the nuclear transduction of Wingless (Wg)/Wnt signals and that Wg signaling antagonizes lobe function. A screen using double hyx/lobe heterozygotes identified an additional interaction with orb and orb2, the homologs of mammalian cytoplasmic polyadenylation element binding protein (CPEB), a translational regulatory protein. Hyx and orb2 heterozygotes lived longer and were more resistant to starvation than controls. In mammalian cells, knockdown of parafibromin expression reduced levels of CPEB1. Chromatin immunoprecipitation (ChIP) showed occupancy of CPEB1 by endogenous parafibromin. Bioinformatic analysis revealed a significant overlap between human transcripts potentially regulated by parafibromin and CPEB. These results show that parafibromin may exert both transcriptional and, through CPEB, translational control over a subset of target genes and that loss of parafibromin (and CPEB) function may promote tumorigenesis in part by conferring resistance to nutritional stress.

Cigarette smoking and innate immunity

Cigarette smoking is a worldwide epidemic and the most prevalent cause of many diseases leading to increased morbidity and mortality globally. The impact of smoking on pathogenesis of cancer is being extensively studied however cigarette smoke as an immunosuppressant is less well recognized. Here we review the immunosuppressive effects of cigarette smoke and the mechanisms by which smoking affects host innate immunity including structural and functional changes in the respiratory ciliary epithelium, lung surfactant protein, and immune cells such as alveolar macrophages, neutrophils, lymphocytes and natural killer (NK) cells. Thus smoking cessation should be emphasized not only for prevention of cancer and coronary artery disease but also for patients with recurrent infections and immunosuppressive states.

Malignant myelomatous pleural effusion with good response to combination chemotherapy

Malignant pleural effusion in myeloma is a rare terminal event with 91 cases reported so far. Majority of the patients survive less than 4 months. We are presenting a short series of four such cases, who had a good clinical response to combination chemotherapy.

Study on clinico-epidemiological profile of HIV patients in eastern India

In this study, 438 HIV positive patients attending the HIV clinic of Sir Sundar Lal Hospital, IMS, BHU were enrolled. Of these 354 were males (mean CD4 count 179 +/- 9.3 cells/microl) and 84 were females (mean CD4 count 323 +/- 28.26 cells/microl). The mean age of the study subjects at the time of diagnosis was 32.6 years. Heterosexual contact was the commonest mode of transmission in 352 (80.4%) patients followed by blood transfusion in 2.5%. History suggestive of a risk factor for HIV transmission could not be elicited in 62 (14.1%) patients. Among male patients, 71.5% were migrant workers. Fever (70.6%), weight loss (53.3%), chronic diarrhea (43.9%) and cough (40.3%) were the common presenting symptoms. Out of the 438 patients, 66.4% had opportunistic infections at the time of reporting to the hospital. The most common opportunistic infection was tuberculosis (38.8%) followed by oropharyngeal candidiasis (20.3%) and diarrhea (12.7%). CD4 counts of the patients were significantly inversely correlated with the number of symptoms and the number of opportunistic infections (correlation coefficient were -.289 and -.236 respectively).

Complete agenesis of the right and left pulmonary arteries, with main pulmonary artery originating from the right ventricle, presenting as primary pulmonary hypertension of the newborn: case report

A female infant who had been misdiagnosed as having primary pulmonary hypertension of the newborn was found to have agenesis of the branch pulmonary arteries with collateral-dependent pulmonary circulation. The intracardiac anatomy was completely normal. Unifocalization of branch pulmonary artery was done, followed by stenting of the ductus arteriosus.

Percutaneous closure of patent foramen ovale: impact of device design on safety and efficacy

OBJECTIVE

To compare the safety and efficacy of percutaneous closure of patent foramen ovale (PFO) with the Amplatzer PFO occluder (Amplatzer) or the PFO STAR device (STAR) in patients with presumed paradoxical embolism.

METHODS

Implantation characteristics, procedural complications, residual shunt, and recurrence of thromboembolic events were recorded prospectively in 100 consecutive patients undergoing percutaneous PFO closure with the STAR (n = 50) or Amplatzer (n = 50) devices between 1998 and 2001. The study was not randomised. Device implantation was successful in all cases.

RESULTS

There were more procedural complications in the STAR than in the Amplatzer group (8/50 v 1/50, p = 0.01). More than one device placement attempt was an independent predictor of procedural complications (odds ratio (OR) 8.5, 95% confidence interval (CI) 1.3 to 55.8; p = 0.03). A residual shunt six months after PFO closure, assessed by transoesophageal contrast echocardiography, occurred more often in the STAR than the Amplatzer group (17/50 v 3/50, p = 0.004), and was predicted in the STAR group by the use of a device with a 5 mm as opposed to a 3 mm disc connector (OR 6.1, 95% CI 1.1 to 34.0; p = 0.04). The actuarial risk of recurrent thromboembolic events after 3.5 years was 16.8% (95% CI 7.6% to 34.6%) in the STAR and 2.7% (95% CI 0.4% to 17.7%) in the Amplatzer group after three years (p = 0.08).

CONCLUSIONS

Percutaneous PFO closure with the Amplatzer PFO occluder had fewer procedural complications and was more likely to be complete than with the STAR device. These findings underline the importance of device design for successful percutaneous PFO closure.

Review of readmissions due to complications from uterine fibroid embolization

AIM

To determine the frequency, nature and outcome of complications resulting in readmission to hospital following uterine artery embolization (UAE).

MATERIAL AND METHODS

A retrospective review of the medical notes and available imaging of 42 consecutive patients who had undergone elective uterine artery embolization for the treatment of fibroid disease was performed.

RESULTS

The mean age of the patients was 42 years (range 31--54 years) and seven patients (17%) were readmitted to hospital. The median time to readmission was 3 weeks (range 1-29 weeks). All seven patients were admitted with signs and symptoms of infection. In four patients an organism was isolated from high vaginal swabs, and in one patient the midstream urine sample was confirmed as the source of infection. In the other two patients no definite source of infection was identified. All patients were treated with intravenous antibiotics. Six of the seven patients responded to treatment. The remaining patient required hysterectomy for uncontrolled uterine sepsis.

CONCLUSION

Readmission following UAE is common and arises secondary to infection. Infection can occur several months after the procedure.

Noninvasive management of Indian visceral leishmaniasis: clinical application of diagnosis by K39 antigen strip testing at a kala-azar referral unit

Firm diagnosis of visceral leishmaniasis (kala-azar) requires organ aspiration and microscopic examination of tissue specimens. To determine the usefulness of noninvasive diagnosis by strip test detection of anti-K39 immunoglobulin (Ig) G antibody in blood specimens obtained by fingerstick, 143 Indian patients with suspected kala-azar (fever, splenomegaly, anemia) were studied. Of 120 strip test-positive subjects (subjects with presumed kala-azar [group A]), amphotericin B treatment induced clinical cure in 119. Of 23 strip test-negative subjects (subjects presumed to have other diseases [group B]), 16 had other disorders diagnosed at entry, 4 responded to empiric antimalarial therapy, 2 were proven to have kala-azar, and 1 died elsewhere after undergoing splenic aspiration. Six months after treatment ended, all 120 patients in group A and the 18 assessable patients in group B were healthy. In a region in India where visceral infection is prevalent, strip test detection of anti-K39 IgG is a clinically promising diagnostic guide in persons with suspected kala-azar.

Frequency distribution of collateral flow and factors influencing collateral channel development. Functional collateral channel measurement in 450 patients with coronary artery disease

OBJECTIVES

We sought to determine the pathogenetic predictors of collateral channels in a large cohort of patients with coronary artery disease (CAD).

BACKGROUND

The frequency distribution of collateral flow in patients with CAD is unknown. Only small qualitative studies have investigated which factors influence the development of collateral channels.

METHODS

In 450 patients with one- to three-vessel CAD undergoing percutaneous transluminal coronary angioplasty (PTCA), collateral flow was measured. A collateral flow index (CFI; no unit) expressing collateral flow relative to normal anterograde flow was determined using coronary wedge pressure or Doppler measurements through sensor-tipped PTCA guide wires. Frequency distribution analysis of CFI and univariate and multivariate analyses of 32 factors, including gender, age, patient history, cardiovascular risk factors, medication and coronary angiographic data, were performed.

RESULTS

Two-thirds of the patients had a CFI < 0.25 and approximately 40% of patients had a CFI < 0.15, but only approximately 10% of the patients had a recruitable CFI > or =0.4. By univariate analysis, the following were predictors of CFI > or =0.25: high levels of high-density lipoprotein cholesterol, the absence of previous non-Q-wave myocardial infarction, angina pectoris during an exercise test, angiographic indicators of severe CAD and the left circumflex or right coronary artery as the collateral-receiving vessel. Percent diameter stenosis of the lesion undergoing PTCA was the only independent predictor of a high CFI.

CONCLUSIONS

This large clinical study of patients with CAD in whom collateral flow was quantitatively assessed reveals that two-thirds of the patients do not have enough collateral flow to prevent myocardial ischemia during coronary occlusion, and that coronary lesion severity is the only independent pathogenetic variable related to collateral flow.

Biochemical mechanisms of action of Hypericum LI 160 in glial and neuronal cells: inhibition of neurotransmitter uptake and stimulation of extracellular signal regulated protein kinase

We have investigated biochemical mechanisms that may underlie the antidepressant effects of Hypericum LI 160. We found that LI 160 inhibits uptake of serotonin and norepinephrine in cultures of rat cortical astrocytes. Observed differences in the kinetic parameters Km and Vmax as well as in the recovery of uptake after removal of Hypericum indicates that LI 160 does not affect serotonin and norepinephrine transport in the same manner. This suggests that multiple components of the extract can mediate inhibition of these neurotransmitter transporters. Hypericum LI 160 also inhibits serotonin uptake in neuronal cultures from serotonergic-rich raphe nuclei; concentration-response studies indicate LI 160 is 25 times more potent in terms of inhibition of serotonin uptake in neurons than in astrocytes. In addition, Hypericum LI 160 inhibits norepinephrine uptake in SK-N-SH cells, a human neuroblastoma cell line enriched in norepinephrine transporters. A chemical constituent of LI 160, hyperforin, is about 10 to 20 times more potent than LI 160 in inhibiting neurotransmitter uptake in astrocytes and neuronal cells; this finding is consistent with the observation that hyperforin comprises 5% of LI 160 extracts. As several weeks are needed to achieve a clinical response with antidepressants, we have also investigated whether Hypericum LI 160 affects biochemical mechanisms that underlie long-term changes such as gene expression. We found that LI 160 stimulates a sustained activation of extracellular signal regulated protein kinase (ERK), a key component of a signal transduction pathway involved in gene expression. Taken together, our findings suggest that Hypericum LI 160 can affect rapidly-acting as well as slower-developing, long-term biochemical mechanisms related to depressive disorders.

Effects of p-chlorophenylalanine on striatal acetylcholinesterase activity and on biogenic amine levels in nuclei raphe and caudate-putamen during physostigmine-induced tremor in rats

The biochemical mechanism underlying tremor is unknown. We investigated the effects of p-chlorophenylalanine (pCPA), a serotonin (5-HT) depletor, on the neurochemical processes in nuclei raphe dorsalis (NRD) and caudatus putamen (NCP) paralleling physostigmine-induced tremor in rats. Peak of physostigmine tremor correlated with increase in 5-HT in NRD and NCP, and a decrease in striatal dopamine (DA), as assayed employing high pressure liquid chromotography-electrochemistry. Administration of pCPA caused significant decrease in DA, norepinephrine (NE) and 5-HT levels in both the nuclei, without affecting striatal NE content and acetylcholinesterase activity. pCPA pretreatment significantly inhibited physostigmine-induced tremor and blocked corresponding increase in the levels of 5-HT in NRD and NCP. These results indicate involvement of central 5-HT, but not DA or NE, in the genesis of physostigmine tremor.