METHEMOGLOBINEMIA--AN ALTERNATIVE TREATMENT MODALITY.

Methaemogloninemia is a rare condition characterized by elevated levels of methemoglobin levels. We report a case of a young lady who took thinner (a solvent used in paint). Methemoglobinemia was diagnosed on the basis of saturation gap and elevated methemoglobin levels. She recovered after exchange transfusion, which was done due to non-availability of parenteral methylene blue.

Incidence of retinopathy in chronic hepatitis C patients treated with pegylated interferon alpha 2a and ribavirin combination therapy.

OBJECTIVES: The objective of this study was to determine the incidence of retinopathy in chronic hepatitis C patients treated with Pegylated interferon alpha 2a and Ribavirin. METHODS: This descriptive case series study was conducted in Medical Unit II of the Jinnah Hospital Lahore from September 2012 to February 2013. One hundred chronic hepatitis C patients visiting Medical Unit II outpatient department fulfilling inclusion criteria were selected for this study via non probability purposive sampling. Patients were started on pegylated interferon and ribavirin combination therapy. Subjects were subjected to dilated eye fundoscopic examination at the start of therapy and then after three months of the therapy. RESULTS: One hundred patients were included in this study. Out of these 100 patients 5% developed retinopathy whereas fundus examination was normal in rest of the patients. CONCLUSION: Interferon therapy can lead to retinopathy. Periodic fundoscopic examinations help in early detection and prevent progression to permanent visual loss.

Tuberculosis prevalence and demographic characteristics of population in Azad Jammu and Kashmir (Pakistan): A retrospective study.

Tuberculosis (TB) remains a serious problem for public health and a leading cause of death after COVID-19 and superior to even HIV/AIDS. It is a social health issue and can cause stigma and economic loss as the person cannot perform professionally due to lethargy caused by disease. It is a retrospective study done on data from National TB program Muzaffarabad chapter. The details were noted on SPSS and analysis was done to find important demographic characteristics. The total number of patients was 3441; among which 48.76% were males. Most of them (81.11%) belonged to the Muzaffarabad division of Azad Jammu and Kahmir (AJK). The microbiologically or culture positive cases were 440. Rifampicin resistance was present in 147 cases, further categorized as high (n = 143), very high (n = 3), or true positive (n = 1) resistance. Muti drug resistance was found in 19 cases. The microscopy culture is more sensitive (AUC = 0.511) than MTB/RIF or serology (AUC = 0.502) according to ROC. The rate of positive smear results is not very satisfactory in the present study as it cannot detect dormant or latent cases. There is a need to establish more sensitive tests for detection of cases and more research to combat the disease.

Classification of Pharynx from MRI Using a Visual Analysis Tool to Study Obstructive Sleep Apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is a chronic sleeping disorder. The analysis of the pharynx and its surrounding tissues can play a vital role in understanding the pathogenesis of OSA. Classification of the pharynx is a crucial step in the analysis of OSA. METHODS: A visual analysis-based classifier is developed to classify the pharynx from MRI datasets. The classification pipeline consists of different stages, including pre-processing to select the initial candidates, extraction of categorical and numerical features to form a multidimensional features space, and a supervised classifier trained by using visual analytics and silhouette coefficient to classify the pharynx. RESULTS: The pharynx is classified automatically and gives an approximately 86% Jaccard coefficient by evaluating the classifier on different MRI datasets. The expert's knowledge can be utilized to select the optimal features and their corresponding weights during the training phase of the classifier. CONCLUSION: The proposed classifier is accurate and more efficient in terms of computational cost. It provides additional insight to better understand the influence of different features individually and collectively. It finds its applications in epidemiological studies where large datasets need to be analyzed.

Tactile Perception of Virtual Edges and Gratings Displayed by Friction Modulation via Ultrasonic Actuation.

Tactile discrimination and roughness perception of real textures are extensively studied and underlying perceptual mechanisms are relatively well-established. However, tactile perception of virtual textures rendered by friction modulation techniques on touch surfaces has not been investigated in detail yet. In this article, we investigated our ability to discriminate two consecutive step changes in friction (called edges), followed by discrimination and roughness perception of multiple edges (called periodic gratings). The results showed that discrimination of two consecutive edges was significantly influenced by edge sequence: a step fall in friction ( FF) followed by a step rise in friction ( RF) was discriminated more easily than the reverse order. On the other hand, periodic gratings displayed by consecutive sequences of FF followed by RF were perceived with the same acuity as compared to vice versa. Independent of the edge sequence, we found that a relative difference of 14% in spatial period was required to discriminate two periodic gratings. Moreover, the roughness perception of periodic gratings decreased with increasing spatial period for the range that we have investigated (spatial period 2 mm), despite the lack of spatial cues on grating height. We also observed that rate of change in friction coefficient was better correlated with the roughness perception than the friction coefficient itself. These results will further help to understand and design virtual textures for touch surfaces.

Psychophysical Evaluation of Change in Friction on an Ultrasonically-Actuated Touchscreen.

To render tactile cues on a touchscreen by friction modulation, it is important to understand how humans perceive a change in friction. In this study, we investigate the relations between perceived change in friction on an ultrasonically actuated touchscreen and parameters involved in contact between finger and its surface. We first estimate the perceptual thresholds to detect rising and falling friction while a finger is sliding on the touch surface. Then, we conduct intensity scaling experiments and investigate the effect of finger sliding velocity, normal force, and rise/fall time of vibration amplitude (transition time) on the perceived intensity of change in friction. In order to better understand the role of contact mechanics, we also look into the correlations between the perceived intensities of subjects and several parameters involved in contact. The results of our experiments show that the contrast and rate of change in tangential force were best correlated with the perceived intensity. The subjects perceived rising friction more strongly than falling friction, particularly at higher tangential force contrast. We argue that this is due to hysteresis and viscoelastic behavior of fingertip under tangential loading. The results also showed that transition time and normal force have significant effect on our tactile perception.