A Hydrogel-Based Ultrasonic Backscattering Wireless Biochemical Sensing

Wireless monitoring of the physio-biochemical information is becoming increasingly important for healthcare. In this work, we present a proof-of-concept hydrogel-based wireless biochemical sensing scheme utilizing ultrasound. The sensing system utilizes silica-nanoparticle embedded hydrogel deposited on a thin glass substrate, which presents two prominent interfaces for ultrasonic backscattering (tissue/glass and hydrogel/glass). To overcome the effect of the varying acoustic properties of the intervening biological tissues between the sensor and the external transducer, we implemented a differential mode of ultrasonic back-scattering. Here, we demonstrate a wireless pH measurement with a resolution of 0.2 pH level change and a wireless sensing range around 10 cm in a water tank.

Setting up pharmacovigilance based on available endTB Project data for bedaquiline

SETTING: Active pharmacovigilance (PV) is recommended for TB programmes, notably for multidrug-resistant TB (MDR-TB) patients treated with new drugs. Launched with the support of UNITAID in April 2015, endTB (Expand New Drug markets for TB) facilitated treatment with bedaquiline (BDQ) and/or delamanid of >2600 patients in 17 countries, and contributed to the creation of a central PV unit (PVU).OBJECTIVE: To explain the endTB PVU process by describing the serious adverse events (SAEs) experienced by patients who received BDQ-containing regimens.DESIGN: The overall PV strategy was in line with the ‘advanced´ WHO active TB drug safety monitoring and management (aDSM) system. All adverse events (AEs) of clinical significance were followed up; the PVU focused on signal detection from SAEs.RESULTS and CONCLUSION: Between 1 April 2015 and 31 March 2019, the PVU received and assessed 626 SAEs experienced by 417 BDQ patients. A board of MDR-TB/PV experts reviewed unexpected and possibly drug-related SAEs to detect safety signals. The experts communicated on clusters of risks factors, notably polypharmacy and off-label drug use, encouraging a patient-centred approach of care. Organising advanced PV in routine care is possible but demanding. It is reasonable to expect local/national programmes to focus on clinical management, and to limit reporting to aDSM systems to key data, such as the SAEs.

Introducing new and repurposed TB drugs: the endTB experience

In 2015, the initiative Expand New Drug Markets for TB (endTB) began, with the objective of reducing barriers to access to the new and repurposed TB drugs. Here we describe the major implementation challenges encountered in 17 endTB countries. We provide insights on how national TB programmes and other stakeholders can scale-up the programmatic use of new and repurposed TB drugs, while building scientific evidence about their safety and efficacy. For any new drug or diagnostic, multiple market barriers can slow the pace of scale-up. During 2015-2019, endTB was successful in increasing the number of patients receiving new and repurposed TB drugs in 17 countries. The endTB experience has many lessons, which are relevant to country level introduction of new TB drugs, as well as non-TB drugs and diagnostics. For example: the importation of TB drugs is possible even in the absence of registration; emphasis on good clinical monitoring is more important than pharmacovigilance reporting; national guidelines and expert committees can both facilitate and hinder innovative practice; clinicians use new and repurposed TB drugs when they are available; data collection to generate scientific evidence requires financial and human resources; pilot projects can drive national scale-up.

Complaints of neuropathic pain, noxious cervical plexus neuropathy and neck tightness are reported by patients who undergo neck dissection: an institutional study and narrative review

There exists a subgroup of patients who undergo neck dissection (ND) who postoperatively complain of either neuropathic pain, dysaesthesia and/or discomfort that is located within the dermatomal distribution of the cervical plexus. The purpose of our study was to determine the prevalence, characteristic, and demographics of these symptoms in our patient cohort. We undertook a retrospective randomised observational cohort study of 105 patients who had undergone ND. The primary predictor variable was the undertaking of a ND. The secondary outcome variable was the complaint of either neuropathic pain or a noxious neuropathy, at a minimum of twelve months after surgery. A recognised symptom questionnaire and a visual analogue score was employed for the purpose of the study. A descriptive and statistical analysis was applied to the assembled data. Twenty patients (19%) complained of either spontaneous (n=9) or evoked (n=11) neuropathic pain that occurred within the surgical site. In addition, 71 patients (68%) described an altered sensation in the dermatomal distribution of the great auricular or tranverse cervical nerves while 70 patients (67%) described the feeling of 'neck tightness'. There were no characteristics of the study cohort that underpinned these results. Neuropathic pain can occur following ND. This can cause distress to a small but defined group of patients. Despite its importance, we found a paucity of studies in the literature that have investigated neuropathic pain following ND. We believe this condition requires more research attention and clinical awareness.

Human Oral Motion-Powered Smart Dental Implant (SDI) for In Situ Ambulatory Photo-biomodulation Therapy

Peri-implant disease is an inflammatory condition affecting the soft and hard tissues surrounding a dental implant. However, current preventative methods are insufficient due to the limited bioactivity on the dental implant and poor patient compliance. Recently, photo-biomodulation (PBM) therapy that can recover and regenerate peri-implant soft tissue has attracted considerable attention in dentistry. In this paper, a seamless human oral motion-powered dental implant system (called Smart Dental Implant or SDI) is presented as an ambulatory PBM therapy modality. SDI allows the in situ light delivery, which is enabled by the energy harvesting from dynamic human oral motions (chewing and brushing) via an engineered piezoelectric dental crown, an associated circuit, and micro light emitting diodes (LEDs). The SDI also offers adequate mechanical strength as the clinical standards. Using primary human gingival keratinocytes (HGKs) as a model host organism and Pseudomonas aeruginosa lipopolysaccharides (LPS) as a model inflammatory stimulus, effective SDI-mediated PBM therapy is demonstrated. A new class of dental implants could be an ambulatory PBM therapy platform for the prevention of peri-implant disease without patient dependency, warranting long-lasting dental implants.

Hydrogel-Fractal Piezoelectric Bilayer Transducer for Wireless Biochemical Sensing

This paper reports on a novel transducer for wireless biochemical sensing. The bilayer transducer consists of a fractal piezoelectric membrane and pH-sensitive chemo-mechanical hydrogel, which overcomes many shortcomings in the chemical and biochemical sensing. The fractal design on the piezoelectric membrane enhances frequency response and linearity by employing periodically repeated pore architecture. As a basis of the pore, a Hilbert space-filling curve with modifications is used. On the surface of the fractal piezoelectric membrane, the hydrogel is laminated. When the bilayer transducer is introduced to a pH environment (e.g., pH = 4, 8, and 12), the hydrogel swells (or shrinks) and induces the curling of the bilayer transducer (10.47°/pH). The curvature then exhibits various ultrasound responses when the bilayer transducer was excited. The measured voltage outputs using an ultrasonic receiver were 0.393, 0.341, 0.250 mV/cm² when curvature angles were 30°, 60°, and 120°, respectively. Overall pH sensitivity was 0.017 mV/cm²/pH. Ultimately, the biochemical sensing principle using a novel bilayer ultrasound transducer suggests a simple, low-cost, battery-less, and long-range wireless readout system as compared to traditional biochemical sensing.

P0835IDENTIFYING THE FREQUENCY OF CHRONIC KIDNEY DISEASE OF UNKNOWN ETIOLOGY (CKDU) IN A RURAL POPULATION OF BANGLADESH

Background and Aims

The common etiologies of CKD are diabetes, hypertension and glomerulonephritis. Prevalence of CKD of unknown (CKDu) etiology is being increasingly considered as an emerging etiology, especially in the developing countries, with environmental predisposition to hot humid climate, dehydration and toxic metal contaminations. The aim was to identify the frequency of CKDu as an etiology in a rural population with environmental exposure.

Method

In this observational study subjects were selected from a geographically defined rural population in Bangladesh. Baseline information was recorded by the translated WHO STEP wise approach surveillance- Instrument v.3.1 (Core and Expanded). Blood Pressure was measured by digital blood pressure monitor. Serum creatinine was measured by enzymatic method using assays traceable to isotope dilution mass spectrometry (IDMS). A fasting blood sample and spot urine was collected. BP ≥140/90mmHg; FBS > 5.6 mmol/l and HbA1c ≥6.5%; and eGFR< 60ml/min (CKD-EPI equation) or urine ACR > 30mg/g was taken as diagnostic cut-offs for hypertension, diabetes and nephropathy respectively. From diagnosed CKD patients CKDu group was further identified by stepwise approach of WHO criteria as suspected and probable stages.

Results

The mean age was 41.3 ± 12.7 years with male/female ratio 37/63 in preliminary 303 study subjects. They were 12.5% diabetic, 21% hypertensive and 75% had some form of dyslipidemia. Among all 51 subjects (16.8%) were diagnosed as CKD based on single measurement of eGFR and ACR. Of these 30 study subjects (58%) met the criteria of suspected CKDu. After repeat measures of eGFR and ACR at 3 months, prevalence of CKD came down to 10.2% persisting in 31 subjects (G1:5.3%, G2:2.3% and G3: 2.6%). Of these 7 study subjects (23%) met the criteria of probable CKDu. The main etiologies of CKD among these subjects were diabetic nephropathy (48%) followed by CKDu. The frequency of CKDu in total study population as a whole was 2.3%.The pattern of environmental exposures like types of farming, use of pesticide-fertilizer, NSAIDs intakes, water sources, amount of drinking water per day, duration of work under direct sun, pattern of fish-meat intakes, etc. were not different between subjects with CKDu versus the others.

Conclusion

The prevalence of chronic kidney disease in a rural area of Bangladesh is one in ten (10.2%). Among these nearly one-fourth (23%) of the subjects belonged to probable CKDu category. This alarmingly high frequency of CKDu needs further extensive evaluation to identify the predisposing factors responsible.

Effect of vitamin D on bone strength in older African Americans: a randomized controlled trial

There is controversy over whether African Americans have higher vitamin D requirements than recommended by the Institute of Medicine. We previously reported that maintaining serum 25(OH)D above 30 ng/mL does not prevent age-related bone loss. Herein, we report that bone strength is also unaffected by maintaining this level in this population.

INTRODUCTION

The role of vitamin D in bone strength has not been investigated in the African American (AA) population.

METHODS

A 3-year randomized controlled trial was designed to examine the effect of vitamin D supplementation on physical performance, bone loss, and bone strength in healthy older AA women. A total of 260 postmenopausal AA women, ages ≥ 60 years were randomized to a vitamin D₃ or placebo arm. Vitamin D₃ dose was adjusted to maintain serum 25OHD > 30 ng/mL. Bone mineral density, femoral axis length, and femoral neck (FN) width were measured by dual-energy X-ray absorptiometry. Composite indices of FN strength [compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI)] were computed.

RESULTS

The mean age of participants was 68.2 ± 4.9 years. Baseline characteristics between groups were similar. The average dose of vitamin D₃ was 3490 ± 1465 IU/day in the active group. The mean serum 25OHD was 46.8 ± 1.2 ng/mL versus 20.7 ± 1.1 ng/mL in the active versus placebo group. Serum 25OHD did not correlate with any composite indices. The longitudinal differences observed in FN width, CSI, BSI, and ISI in both groups were not statistically significant (all p values > 0.05). Further, there was no group × time interaction effect for any of the composite indices (all p values > 0.05).

CONCLUSION

Maintaining serum 25OHD > 30 ng/mL (75 nmol/L) does not affect bone strength in older AA women. There is no evidence to support vitamin D intake greater than the recommended RDA by the Institute of Medicine in this population for bone strength.

A Machine Learning Enabled Wireless Intracranial Brain Deformation Sensing System

A leading cause of traumatic brain injury (TBI) is intracranial brain deformation due to mechanical impact. This deformation is viscoelastic and differs from a traditional rigid transformation. In this paper, we describe a machine learning enabled wireless sensing system that predicts the trajectory of intracranial brain deformation. The sensing system consists of an implantable soft magnet and an external magnetic sensor array with a sensing volume of 12 × 12 × 4 mm³. Machine learning algorithm predicts the brain deformation by interpreting the magnetic sensor outputs created by the change in position of the implanted soft magnet. Three different machine learning models were trained on calibration data: (1) random forests, (2) k-nearest neighbors, and (3) a multi-layer perceptron-based neural network. These models were validated using both in vitro (a needle inserted into PVC gel) and in vivo (blast exposure to live and dead rat brains) experiments. The in vitro gel deformation predicted by these machine learning models showed excellent agreement with the camera measurements and had absolute error = 138 μm, Fréchet distance = 372 μm with normalized Procrustes disparity = 0.034. The in vivo brain deformation predicted by these models had absolute error = 50 μm, Fréchet distance = 95 μm with normalized Procrustes disparity = 0.055 for dead animal and absolute error = 125 μm, Fréchet distance = 289 μm with normalized Procrustes disparity = 0.2 for live animal respectively. These results suggest that the proposed machine learning enabled sensor system can be an effective tool for measuring in situ brain deformation.

Association of Hyperbilirubinemia Requiring Phototherapy or Exchange Transfusion with Hearing Impairment among Admitted Term and Late Preterm Newborn in a NICU

Hearing impairment is one of the deleterious ramifications of neonatal hyperbilirubinemia, but its impact during the newborn period has not been well studied in Bangladesh. This prospective observational study was conducted during January 2016 to December 2017 in the Department of Neonatology and Otolaryngology-Head and Neck Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh to identify the relationship between hyperbilirubinemia requiring phototherapy or exchange transfusion with hearing impairment in term and late preterm neonates. Admitted term and late preterm neonates with hyperbilirubinemia requiring either phototherapy or exchange transfusion were taken as hyperbilirubinemia group. Neonates without hyperbilirubinemia from postnatal ward were taken as control. All newborn were screened with Distortion Product Otoacoustic Emissions (DPOAE) prior to discharge from hospital. A second screen was done in referred newborn after one month of first screen. A diagnostic Auditory Brainstem Response (ABR) was performed in both the ears prior to 3 months of postnatal age if referred in both 1st and 2nd screen. Total 264 neonates included in this study; 132 in the hyperbilirubinemia and 132 in the control group. In the hyperbilirubinemia group 74(56.06%) were male and 58(43.94) were female. Mean gestational ages in the hyperbilirubinemia group and control group were 36.95±1.60 weeks and 37.01±1.67 weeks respectively. Newborn in the hyperbilirubinemia group, 4(3.03%) had hearing impairment and none had hearing impairment in the control group. Peak Total Serum Bilirubin (TSB) 23mg/dl was found as best cut off value with a sensitivity of 100% and specificity of 93% for the development hearing impairment. Hearing impairment was significantly more frequent among newborn with TSB level >23mg/dl when compared to those having TSB level ≤23mg/dl (20% vs. 0.9%, p=0.009; OR=29, 95% CI 2.79, 301). Hearing impairment was associated with newborns with hyperbilirubinemia requiring phototherapy or exchange transfusion. Peak TSB level >23mg/dl can be predictive for the development of hearing impairment.

Proton pump inhibitors and histamine-2 receptor antagonists on the risk of pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

Proton pump inhibitors (PPI) and histamine-2 receptor antagonists (H2RA) have been widely used for multiple purposes. Recent studies have suggested an association between these medications and the risk of pancreatic cancer. However, the results have been inconclusive.

AIM

We, therefore, conducted a study to assess the risk of developing pancreatic cancer in patients who used PPI and H2RA.

DESIGN

A systematic review and meta-analysis.

METHODS

A literature search was performed using MEDLINE and EMBASE databases from inception through February 2019. Studies that reported risk ratio comparing the risk of pancreatic cancer in patients who received PPI or H2RA versus those who did not receive treatments were included. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated using a random-effect generic inverse variance method. Sensitivity analysis, excluding one study at a time, was performed.

RESULTS

After screening abstracts from the searching methods, seven studies (six case-control studies and one cohort study) were included in the analysis with total 546 199 participants. Compared to patients who did not take medications, the pooled RR of developing pancreatic cancer in patients receiving PPI and H2RA were 1.73 (95% CI: 1.16-2.57) and 1.26 (95% CI: 1.02-1.57), respectively. However, the sensitivity analysis of PPI changed the pooled RR to 1.87 (95% CI: 1.00-3.51) after a study was dropped out. Likewise, H2RA sensitivity analysis also resulted in non-significant pooled RR.

CONCLUSIONS

This meta-analysis did not find the strong evidence for the associations between the use of PPI and H2RA and pancreatic cancer.

Financial support to the poor for the detection of smear-negative pulmonary and extra-pulmonary TB in Bangladesh

BACKGROUND: The study was conducted in BRAC-administered areas of the Bangladesh National Tuberculosis (TB) Programme (42 of 64 districts). According to the 2013-2017 financial support scheme, direct costs due to TB diagnosis were reimbursed among economically disadvantaged people with presumptive smear-negative pulmonary (PTB) and extrapulmonary TB (EPTB).OBJECTIVE: To describe the implementation of the scheme and associated changes in case notification.DESIGN: This was a descriptive study involving programme data.RESULTS: Between 2013 and 2017, persons reimbursed reduced from 125 680 to 88 763, and the case detection ratio increased from 18% to 24%. The number of patients with presumptive EPTB who were reimbursed decreased from 5024 to 3484. More than 95% were reimbursed for chest radiograph, fine-needle aspiration cytology and biopsy. However, large numbers of ancillary investigations were also reimbursed. During 2013-2017, the observed national quarterly new smear-negative PTB case notification rates (CNRs) were significantly higher than the forecasted CNRs (based on CNR trends during 2008-2012). New EPTB and all form TB CNRs increased but not significantly.CONCLUSION: Implementation of the financial support scheme was accompanied by a significant improvement in new, smear-negative PTB notification. The absence of a comparison arm was a key limitation, but comparison was not possible as the scheme was implemented in all districts.

An Ultrasonically Powered Implantable Microprobe for Electrolytic Ablation

Electrolytic ablation (EA) is a promising nonthermal tumor ablation technique that destroys malignant cells through induction of a locoregional pH change. EA is typically performed by inserting needle electrodes inside the tumor followed by application of direct current (DC), thus inducing electrolysis and creating localized pH changes around the electrodes. In this paper, we report an ultrasonically powered implantable EA microprobe that may increase the clinical relevance of EA by allowing wireless control over device operation (capability to remotely turn the device on and off) and providing flexibility in treatment options (easier to administer fractionated doses over a longer period). The wireless EA microprobe consists of a millimeter-sized piezoelectric ultrasonic receiver, a rectifier circuit, and a pair of platinum electrodes (overall size is 9 × 3 × 2 mm³). Once implanted through a minimally invasive procedure, the microprobe can stay within a solid tumor and be repeatedly used as needed. Ultrasonic power allows for efficient power delivery to mm-scale devices implanted deep within soft tissues of the body. The microprobe is capable of producing a direct current of 90 µA at a voltage of 5 V across the electrodes under low-intensity ultrasound (~200 mW/cm²). The DC power creates acidic (pH < 2) and alkaline (pH > 12.9) regions around the anode and the cathode, respectively. The pH change, measured using tissue-mimicking agarose gel, extends to 0.8 cm³ in volume within an hour at an expansion rate of 0.5 mm³/min. The microprobe-mediated EA ablative capability is demonstrated in vitro in cancer cells and ex vivo in mouse liver.

Neuro-Imaging Changes in Cerebral Palsy: A Cross Sectional Study

Cerebral palsy (CP) is a non- progressive disorder of movement and posture due to a lesion of the developing brain. It is the commonest physical disability in childhood that affects function and development. Neuro imaging is currently recommended as a standard evaluation in children with cerebral palsy. This hospital based cross-sectional study was conducted in Paediatric Neurology out-patient department of Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from July 2015 to December 2015 to see the frequency and pattern of neuro-imaging findings in children with cerebral palsy. A total of 130 cases those who were attended and diagnosed as cerebral palsy based on history, clinical examination and neuro developmental assessment included in this study. All patients were sent to radiology & imaging department of same hospital for CT scan of brain. Among total 130 cerebral palsy patients male were more affected than female (88 boys and 42 girls) with male to female ratio 2.09: 1. Their ages ranged between 6-72 months with a mean age 25.6 months. The commonest age group was 6-24 months (46.9%). Common mode of delivery was normal vaginal delivery (62.3%) & Perinatal asphyxia (PNA) occurred in 66.9% cases. The commonest type of cerebral palsy was spastic form. Among them most cases were quadriplegic type, 64 cases (53.3%). Other cases were hemiplegic 27(20.7%) diplegic 13(10.0%). Total 84.7% had documented cerebral neuroimaging abnormalities; among them, diffuse cortical atrophy (46.9%), encephalomalacic change (19.9%), malformation (6.1%), and calcification (5.3%). CT scan was normal in 15.3% cases of cerebral palsy. The commonest co morbidity was speech delay (50%). Most of the patient with CP had abnormal CT scan finding though some patient had normal CT scan. Diffuse cerebral atrophy and encephalomalacic changes constitute frequent CT neuroimaging findings and commonly found in quadriplegic type of cerebral pulsy patients. Though diagnosis of cerebral palsy is essentially clinical, neuro imaging improves the understanding of the neuro-anatomical basis for function in CP. Etiology, type of CP and extent of motor impairments can easily be identified by the neuro imaging.

Association of Estimated GFR (By MDRD) with the Carotid Intima Media Thickness (CIMT) in Different Stages of CKD among Patients with Type 2 Diabetes Mellitus

Most of the mortalities among Diabetic Nephropathy patients are cardiovascular, if we identify the risk factor, measures can be taken to prevent it. Hence an objective was set to evaluate the association between carotid artery intima media thickness (CIMT) with eGFR in patients of CKD stage III, IV and V among patients with type 2 diabetes mellitus; also, correlation with age, BMI, lipid profile. This cross-sectional, observational study was performed in 70 patients in different stages of CKD in Diabetic Patients selected by Inclusion Criteria (Diabetic nephropathy patients with stages III, IV, V and exclusion Criteria (Acute kidney injury, History of carotid surgery, Patients of MI and stroke). This study was performed in Department of Nephrology, Dhaka Medical College in collaboration with the Department of Radiology and Imaging, laboratory of Department of Biochemistry and Department of Microbiology at Dhaka Medical College Hospital (By standard method in laboratory) from 1st January 2016 to 31st December 2016. eGFR was measured by MDRD formula and the CIMT was measured using an ultrasonographic examination. The mean CIMT was 0.9±0.21mm, and 62.9% of the subjects showed IMT thickening (≥1mm). The carotid IMT elevated significantly with the stage progression of CKD (Overall eGFR mean 28.8±14.5mL/min/1.73m² in CIMT<1mm with range from 6 to 54 and 9.1±9.0mL/min/1.73m² in CIMT ≥1mm with range from 3 to 32 (p=0.001). The eGFR was significantly lower in the patients with CIMT thickening than those without CIMT thickening. eGFR was also significantly associated with CKD stages (p=0.001), serum creatinine (p=0.001), BMI (r = -0.330, p=0.005), and negatively associated with age group, duration of hypertension, smoking. However, the CIMT was not significantly different among the patients at different stages of diabetic nephropathy (r = -0.172, p=156) and age group. It has been concluded that the mean CIMT was markedly high in patients with CKD compared to normal expected value. This study showed a relationship between the CIMT and the renal parameters as eGFR and the stages of diabetic nephropathy with a confirm association between the CIMT and diabetic macroangiopathy.