Post-Operative Severe Hyperbilirubinemia: A Case Report.

Hyperbilirubinemia is commonly seen in medical practice. But what could be the highest level of bilirubin in an individual that is still an unanswered question. We came across to a 37 years old lady in October 2018 with hepaticolithiasis who underwent extended choledocholithotomy. Her preoperative serum bilirubin was within normal range. Post-operatively she developed cholangitis and from 3rd post-operative day onwards she developed severe hyperbilirubinemia, which was high as 70.47 mg/dl on the 6th post-operative day. Other causes of post-operative hyperbilirubinemia were excluded. She was managed conservatively for this hyperbilirubinemia and bilirubin level gradually reduced.

Development and performance assessment of new solar and fuel cell-powered oxygen generators and ventilators for COVID-19 patients.

In this study, a new solar-based fuel cell-powered oxygenation and ventilation system is presented for COVID-19 patients. Solar energy is utilized to operate the developed system through photovoltaic panels. The method of water splitting is utilized to generate the required oxygen through the operation of a proton exchange membrane water electrolyser. Moreover, the hydrogen produced during water splitting is utilized as fuel to operate the fuel cell system during low solar availability or the absence of solar irradiation. Transient simulations and thermodynamic analyses of the developed system are performed by accounting for the changes in solar radiation intensities during the year. The daily oxygen generation is found to vary between 170.4 kg/day and 614.2 kg/day during the year. Furthermore, the amount of daily hydrogen production varies between 21.3 kg/day and 76.8 kg/day. The peak oxygen generation rate attains a value of 18.6 g/s. Moreover, the water electrolysis subsystem entails daily exergy destruction in the range of 139.9-529.7 kWh. The maximum efficiencies of the developed system are found to be 14.3% energetically and 13.4% exergetically.

Development and analysis of a new renewable energy-based industrial wastewater treatment system.

In this research study, a new solar energy-based integrated system is developed for treating industrial brine wastewater. An integrated solar-powered evaporation and membrane-based water treatment technique is utilized. Both forced convection as well as falling film evaporators are incorporated to treat high-concentration rejected brine. The system performance is assessed through a comprehensive thermodynamic investigation at varying operating parameters. The energetic performance is evaluated to vary from 12.5% to 15.9% across the year. Furthermore, the peak efficiency in terms of exergy is found to be 11.1%. Also, the membrane-based wastewater treatment subsystem is found to entail an energetic performance of 73.3% and an exergetic performance of 34.6% in terms of efficiencies. Moreover, an energetic performance of 15.4% and an exergetic performance of 2.9% is found for the evaporation-based subsystem. The exergy destructions in each system component are evaluated and the power generation subsystem is determined to have the highest exergy destruction rate of 15.4 MW. To investigate the effects of varying design parameters and operating conditions on the system performance, several parametric studies are also performed.

A THz graphene metasurface for polarization selective virus sensing.

We propose a novel method to exploit chirality of highly sensitive graphene plasmonic metasurfaces to characterize complex refractive indexes (RI) of viruses by detecting the polarization state of the reflected electric fields in the THz spectrum. A dispersive graphene metasurface is designed to produce chiral surface currents to couple linearly polarized incident fields to circularly polarized reflected fields. The metasurface sensing sensitivity is the result of surface plasmon currents that flow in a chiral fashion with strong intensity due to the underlying geometrical resonance. Consequently, unique polarization states are observed in the far-field with the ellipticity values that change rapidly with the analyte's RI. The determination of bimolecular RI is treated as an inverse problem in which the polarization states of the virus is compared with a pre-calculated calibration model that is obtained by full-wave electromagnetic simulations. We demonstrate the polarization selective sensing method by RI discrimination of three different types of Avian Influenza (AI) viruses including H1N1, H5N2, and H9N2 is possible. Since the proposed virus characterization method only requires determination of the polarization ellipses including its orientation at monochromatic frequency, the required instrumentation is simpler compared to traditional spectroscopic methods which need a broadband frequency scan.

A Rare Case of Insulinoma: A Case Report.

Insulinoma is a rare variety of endocrine neoplasm and is usually benign, solitary, and small in size. The hallmark of this disorder is high endogenous insulin secretion resulting in development of symptoms of hypoglycemia. Insulinomas account for 60% of islet cell tumors (ICT) of the pancreas. Ninety percent (90%) of the insulinomas measure less than 2cm. Early localization of the disease is essential to prevent lethal hypoglycemia. Here we report a case of insulinoma in a 28 year old female who subsequently underwent distal pancreatectomy with splenectomy on February 2017 in Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh.

A study on gender-related differences in laboratory characteristics of dengue fever.

Studies have reported significant gender-related differences in serological tests for detection of NS1 antigen and IgM antibody used for diagnosing dengue fever. However, no such study has been undertaken in India though dengue fever is endemic in this country. Therefore, this study was planned to study the association of serological findings with gender in 700 patients suspected to be suffering from dengue fever in the Indian setting. Haematological parameters of seropositive patients were also studied. Seropositivity and haemorrhagic findings were significantly associated with the female gender. Positive NS1 antigen and IgM antibody results were significantly associated with females and males, respectively.

Accuracy of urine collection methods compared to measured GFR in adults with liver disease.

BACKGROUND: Assessment of kidney function is necessary to stage kidney disease, dose medications, and to make decisions about organ allocation. Estimating equations that incorporate serum creatinine (SCr) are not consistently reliable. However, assessment of creatinine clearance (CrCl) using 24-hour urine collection methods is also prone to errors. The purpose of this study was to evaluate the accuracy of measured CrCl determined using shorter urine collection times compared to glomerular filtration rate measured by (125)I-iothalamate clearance ((125)I-CL) in patients with liver disease. METHODS: Adult patients with chronic liver disease were enrolled. All patients received (125)I-iothalamate and had a catheter placed for urine collection. Blood samples were collected at designated times over 8 hours to determine (125)I-CL. CrCl was determined from a 1-hour and a 4-hour urine collection and compared to (125)I-CL. RESULTS: Characteristics of the eight patients enrolled included age 52 ± 6 years; SCr 1.2 ± 0.4 mg/dL; and Model for End-stage Liver Disease score of 13 ± 3. All patients were Child-Pugh Class B. Mean estimates of kidney function (mean ± SD, mL/min/1.73 m(2)) by method were 74 ± 38 for (125)I-CL, 79 ± 28 for the 1-hour urine collection, and 72 ± 26 for the 4-hour urine collection. Measured CrCl did not differ significantly from (125)I-CL (P = .641 for 1-hour CrCl versus (125)I-CL, and P = 1.0 for the 4-hour CrCl versus (125)I-CL). CONCLUSION: When urine collection methods are necessary for an individualized assessment of kidney function, shorter collection times can provide accurate results and would be more feasible for the patient.

Dieulafoy's lesion: an overview.

Dieulafoy's lesion accounts for 1-5.8% of cases of acute upper GI bleeding. The two largest retrospective series, both from North America, found Dieulafoy's lesion as the source of hemorrhage in 1.9% and 1.2% of all endoscopies performed for acute GI bleeding. In the prospective study of Chung et al., Dieulafoy's Lesion was found in 3.4% of all patients with acute GI bleeding referred to their unit. The Dieulafoy's Lesion accounted for up to 40% of all causes of nonvariceal upper GI bleeding not caused by gastric or duodenal ulceration or esophageal varices in the prospective study of Matsui et al. In the study of Schmulewitz and Bailli, colonic Dieulafoy's Lesion were only found in 0.09% of all colonoscopies performed for lower GI bleeding. The actual incidence of both upper and lower GI bleeding from Dieulafoy's Lesion is likely higher than estimated because the diagnosis remains difficult. Recent advances in endoscopy have led to an increased detection of Dieulafoy's lesions. Initial GI endoscopy is effective in diagnosing up to 70% of patients. Several endoscopies may be required with 6% of patients, requiring three or more to establish the diagnosis. Angiography and/or red cell scanning can be used when endoscopy fails to diagnose a doubtful case. There is no definite unique policy for the treatment of Dieulafoy's lesions. Therapeutic endoscopy remains the first line of treatment option for controlling the bleeding while angiography is considered as a valuable alternative. Surgical intervention is kept for failure cases where it should be guided by preoperative localization. The mortality rate has decreased dramatically from 80% to 8.6% in recent times due to advancement in both diagnostic and therapeutic tools.

A comparative study of the efficacy of Pediatric Airtraq® with conventional laryngoscope in children.

BACKGROUND: Management of pediatric airway may pose a challenge to anesthesiologists. Many modifications in maneuvers and equipments have been made overtime to overcome the problem. Pediatric optical laryngoscope (Airtraq®) is one of the newer equipments for managing simple and difficult pediatric airway. Here we have evaluated the comparative efficacy of pediatric Airtraq® optical laryngoscope with conventional laryngoscope in children scheduled for routine surgeries. METHODS: After written informed consent from the parents/guardian of the children, they were allocated into two groups of 17 patients each using the pediatric Airtraq® in one and a conventional laryngoscope in the other. Airtraq® intubation patients were those in which pediatric Airtraq® was used to intubate whereas the patients who were intubated with conventional laryngoscope were labelled as conventional intubation group. The primary outcome measure was time needed for successful intubation whereas secondary outcome measures were number of attempts to intubate, POGO (percentage of glottic opening) scoring and complications like airway trauma and esophageal intubation. RESULTS: It took significantly shorter time to intubate in Airtraq® intubation group of patients as compared to Conventional intubation group of patients (P<0.05). Similarly the POGO scoring was significantly better in Airtraq intubation compared to Conventional intubation (P <0.001). Number of attempts to intubate and complications like airway trauma and esophageal intubation using Airtraq® was less frequent compared to conventional laryngoscopy but the difference was statistically insignificant. CONCLUSION: Pediatric Airtraq® provides better intubating conditions in children compared to conventional laryngoscope with less frequent complications.

Ventral free oral mucous membrane graft for bulbar urethral stricture.

The use of oral mucous membrane graft onlay urethroplasty represents the most widespread method of bulbar urethral stricture repair. We investigated the short term result of oral mucous membrane graft placed on the ventral surface for management of bulbar urethral stricture. Patients with Bulbar urethral stricture of any length, infection free urinary tract and informed consent for oral mucosa harvesting and urethroplasty were selected for study. We enrolled 108 cases of bulbar urethral stricture patients from January 2004 to July 2009. The mean ± SD preoperative maximum flow rate of 5.2 ± 2.6 ml/sec and mean ± SD PVR 87 ± 58.3 ml were treated by substitution urethroplasty with oral mucous membrane by a single surgical team in a private hospital. Causes of stricture were trauma 26(24.1%), infection 58(53.7%), catheter induced 8(7.4%), post TURP 11(10.2%) and unknown 5(4.6%). Oral mucous membrane was harvested from the cheek or from the inner side of lower lip. Defect of the urethra displayed by longitudinal ventral urethrotomy and the graft was sutured over the edges of the incised urethral mucosa over a 14 Fr latex Foley's catheter. Spongiosum tissue was closed over the graft. Pericatheter urethrogram was performed in all cases to check for the anastomotic leakage and the Catheter was removed after 2 weeks of the procedure. After removal of catheter uroflowmetry & ultrasound scan of bladder were performed to estimate the maximum flow rate and post voidal residue. The patient was followed-up every 3 months with uroflowmetry & ultrasonography. The median (range) age of the patients was 32(21-72) years. Mean follow up period was 36 months (range 12-54). Mean ± SD stricture length was 3.7 ± 2.6 cm. The overall success rate was 91.7%. Mean ± SD flow rate was 23 ± 4.2 ml/sec, mean ± SD post void residue was 25 ± 15.5 ml and patient quality of life (QOL) was excellent in almost all patients. Overall complications were seen in 9(8.3%) cases. Of which, restricture occurred in 6 patients; periurethral fistulae seen in 2 cases and per urethral bleeding in 1 patient. No significant complications were observed at the donor site. Oral numbness and mild discomfort complained by 67.6% patients which were managed by reassurance only. In our experience ventral placement of oral mucous membrane graft along with spongioplasty is a very easy procedure with very encouraging short term result.

A case of renal infarction associated with elevated factor VIII level.

Elevated factor VIII level has recently been shown to be associated with increased risk of thrombosis. We report here a case of renal infarction in association with elevated factor VIII level. The patient presented with a three-day history of flank pain. Laboratory studies on presentation showed an elevated serum creatinine concentration and microscopic hematuria. He was found to have bilateral pulmonary emboli and left common femoral vein thrombosis; imaging studies showed evidence of renal arterial thrombosis with infarction. Hypercoagulability assessment showed an elevated factor VIII level. He was treated with heparin and warfarin with significant improvement in his renal function. Consideration should be given to measurement of factor VIII level as a part of the workup of unexplained thrombo-embolic events.

Holographic three-dimensional telepresence using large-area photorefractive polymer.

Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.

Random-effects regression analysis of correlated grouped-time survival data.

Random-effects regression modelling is proposed for analysis of correlated grouped-time survival data. Two analysis approaches are considered. The first treats survival time as an ordinal outcome, which is either right-censored or not. The second approach treats survival time as a set of dichotomous indicators of whether the event occurred for time periods up to the period of the event or censor. For either approach both proportional hazards and proportional odds versions of the random-effects model are developed, while partial proportional hazards and odds generalizations are described for the latter approach. For estimation, a full-information maximum marginal likelihood solution is implemented using numerical quadrature to integrate over the distribution of multiple random effects. The quadrature solution allows some flexibility in the choice of distributions for the random effects; both normal and rectangular distributions are considered in this article. An analysis of a dataset where students are clustered within schools is used to illustrate features of random-effects analysis of clustered grouped-time survival data.

Multiple imputation compared with some informative dropout procedures in the estimation and comparison of rates of change in longitudinal clinical trials with dropouts.

Statistical analysis based on multiple imputation (MI) of missing data when analyzing data with missing observations is gaining popularity among statisticians because of availability of computing softwares; it might be tempting to use MI whenever data is missing. An important assumption behind MI is the "ignorability of missingness." In this paper, we demonstrate the use of MI in conjunction with random effects models and several other methods that are devised to handle nonignorable missingness (informative dropouts). We then compare the results to assess sensitivity to underlying assumptions. Our focus is primarily to estimate and compare rates of change (of a primary variable). The application dataset has a high dropout rate and has features to suggest informativeness of the dropout process. The estimates obtained under random effects modeling with multiple imputation were found to differ substantially from those obtained by methods devised to handle informative dropouts.

Linear structural equation model in analyzing quality-of-life-data from clinical trials.

Assessment of quality of life (QOL) in clinical trials becomes a challenging task from the viewpoint of clinical biostatistics. The responses of the items for measuring QOL indices usually vary widely from patient to patient and from time to time. Measurement errors might be present in the responses of the items, and they might be correlated. Hence, in analyzing QOL data, the usual assumption that there are no measurement errors in responses is too liberal. Because the QOL indices are likely to be correlated, separate analysis of each index might not be efficient from the point of view of statistical methodology. We apply linear structural equation modeling (LISREL) in assessing the QOL data obtained from a clinical trial. A basic premise of the LISREL approach is that the abstract concepts (latent constructs) that are not directly measurable can be studied. LISREL is a statistical procedure for conceiving and testing structural hypotheses that cannot be tested adequately with other statistical procedures. It allows us to specify relations between unobserved and observed variables while controlling for measurement errors and correlations among both the measurement errors and the latent constructs.

The application of Poisson random-effects regression models to the analyses of adolescents' current level of smoking.

BACKGROUND: In school-based smoking prevention research, it is still debatable whether parents or peers are most influential to maintained smoking among adolescents. As a result, this study examines the effects of parental and peer approval of smoking on adolescents' current levels of smoking. METHODS: Poisson random-effects regression models were used to assess the effects of parental and peer approval of smoking on adolescents' (n = 913) current level of smoking. RESULTS: Results of these analyses indicate that a stronger relationship between parental approval of smoking and current level of smoking was found for female adolescents than for male adolescents. Conversely, a stronger relationship between peer approval of smoking and current level of smoking was found for male adolescents than for female adolescents. With respect to race, the influence of parental approval of smoking on adolescents' current level of smoking was generally more pronounced for minority adolescents, relative to white adolescents. However, the influence of peer approval of smoking on current level of smoking was strongest for white adolescents and was less strong for black, Hispanic, and Asian adolescents. CONCLUSION: The findings of this study demonstrated that the effects of parental and peer approval of smoking on adolescents' current levels of smoking were varied by gender and race. These differential effects may have some implication for the development of future school-based smoking prevention and cessation programs.

Characteristics of inconsistent respondents who have "ever used" drugs in a school-based sample.

This study examines the predictors of inconsistent responses from adolescents to questions about whether they ever used alcohol, cigarettes, and marijuana. Male adolescents had significantly higher rates of inconsistent responses than female adolescents. Black and Hispanic adolescents had significantly higher rates of inconsistent responses regarding ever using alcohol and cigarettes (only for Black) than White adolescents. The subjects' living status and academic achievements were significant predictors of inconsistent responses regarding ever using marijuana. Thus, these results are consistent with the notion that inconsistent responses may bias the estimation of the prevalence of ever using drugs in multivariate analyses.

A comparison of the random-effects pattern mixture model with last-observation-carried-forward (LOCF) analysis in longitudinal clinical trials with dropouts.

The last-observation-carried-forward imputation method is commonly used for imputting data missing due to dropouts in longitudinal clinical trials. The method assumes that outcome remains constant at the last observed value after dropout, which is unlikely in many clinical trials. Recently, random-effects regression models have become popular for analysis of longitudinal clinical trial data with dropouts. However, inference obtained from random-effects regression models is valid when the missing-at-random dropout process is present. The random-effects pattern-mixture model, on the other hand, provides an approach that is valid under more general missingness mechanisms. In this article we describe the use of random-effects pattern-mixture models under different patterns for dropouts. First, subjects are divided into groups depending on their missing-data patterns, and then model parameters are estimated for each pattern. Finally, overall estimates are obtained by averaging over the missing-data patterns and corresponding standard errors are obtained using the delta method. A typical longitudinal clinical trial data set is used to illustrate and compare the above methods of data analyses in the presence of missing data due to dropouts.

Patterns of use of smokeless tobacco and the unidimensional model of drug involvement.

The present study tested whether smokeless tobacco (ST) fits a unidimensional model of drug involvement and tried to locate ST along the dimension that underlies drug use. The latent trait analysis was employed to quantify drug involvement in a sample of high school students. Analyses showed that although ST use fits the unidimensional model of drug involvement, the place of ST use along the continuum of drug involvement is not stable and differs by gender and ethnicity. Particularly for males, ST use is likely to be preceded by soft drug use and followed by hard drug use; for females, however, ST use is closely associated with hard drug use. The analyses also revealed that the fit of the unidimensional model and the location of ST use along the dimension vary with different ethnic groups.

Factors affecting attrition in a longitudinal smoking prevention study.

BACKGROUND: In longitudinal smoking prevention studies, a difficulty in evaluating treatment effects is understanding whether bias is associated with those who do not complete the study. This study presents the significant predictors of attrition and suggests how to reduce attrition bias in evaluating program effects. METHODS: Survival analysis methods were used to assess factors associated with attrition at different time points of the study. RESULTS: Results of the analysis indicate that those who drop out tend to be of lower academic achievement, have lower tobacco and health knowledge, and have lower social influence/resistance skills knowledge, and are more likely to be smokers and to be marijuana users. Blacks are more likely to drop out than the other ethnic groups. Gender is not a significant predictor for dropout. The dropout rates among the treatment conditions are significantly different. CONCLUSIONS: The findings of this study demonstrate that attritions in longitudinal smoking prevention studies are not at random. By considering the characteristics of dropouts, one can reduce attrition bias using available procedures and can take appropriate strategies for reducing dropout rates in future smoking prevention studies.