On-chip stool liquefaction via acoustofluidics.

Purpose: The aim of this research was to determine prevalence of fascioliasis by examination of liver for adult flukes and bovine stool at the farm in Uasin Gishu County. Methodology: Stool examination and routine meat examination procedures were used. Findings: The results at postmortem showed that female bovine were significantly (P<0.05) more infected (47.4%) compared to male cattle (32.8%). Ayrshire breed had higher infection rate (38.1%) compared to the other breeds, with the local breed having a significantly (p < 0.05) lowest infection rate (11.5%) Older cattle (over 48 months) had a significantly (p < 0.05) higher infection compared to the younger age groups. More slaughtered cattle were sourced from Uasin Gishu compared to other regions and they were also significantly (P<0.05) more infected (at 47.1%) than cattle from the other regions. Results for stool examination also had a similar trend. There was a significant difference in the rates of Fasciola infections in cattle in the six Sub counties. Fasciola infection between the male and female, between Ayrshire, Friesian and local breed, between age 8-24, age 25-48 and age 48 were also significant. More females were infected followed by animals aged between 25-48 months. Friesian breed was the most infected and sampled on farms in the field among the breeds with the least infected being the local breeds which showed more resistance to fascioliasis than the other groups. F. hepatica was the most common species infecting the cattle, although some animals were found to have mixed infections. The results of stool analysis also showed that more female cattle and the animals aged between 25-48 months were more infected. Friesian breed were more infected during stool examination among the bovine breeds with the least infected being local breeds which suggests that they are more resistance to fascioliasis than the exotic breeds. Stool analysis prevalence was 28% while liver examination was 40%. Stool analysis was found to be a suitable method for routine management of livestock in order to reduce losses that are associated with liver flukes. Unique contribution to theory, policy and practice: Uasin Gishu contributed the highest number of slaughtered animals in the Eldoret main abattoir and therefore farmers in the region should be advised on the best cattle management practices such as regular stool analysis deworming and avoiding grazing their cattle in potentially snail infested areas.

Chapter 2 - Critical factors affecting cells behavior in microfluidic chips

Stool analysis is commonly performed to diagnose certain gastrointestinal diseases. The diagnostic yield of stool culture, a method of stool analysis, is variable worldwide and is unclear in the Kingdom of Saudi Arabia. This study was conducted to determine the diagnostic yield of stool culture from the year 2008 to 2020 and to determine the predictors for a positive stool culture. Furthermore, antibiotic susceptibility patterns of the detected copro-pathogens in the same time period were collected and studied. This is a retrospective case-control study in which patients' data was collected from the hospital's electronic health record. The results of all stool analyses performed from 2008 to 2020 and associated patients' characteristics were collected. Characteristics of cases with a positive stool culture were compared to the characteristics of those without to identify the predictors for positive stool cultures. Copro-pathogens were detected in 89.4% of cultured stool samples. Salmonella spp (1590/1775, 89.6%) was the most common organism followed by Shigella spp. (84/1775, 4.7%) and Campylobacter spp (45/1775, 2.5%). Male sex, the 1-5 age group, positive fecal occult blood test results, and positive stool leukocyte test results were associated with a positive stool culture result. Cultured copro-pathogens were highly sensitive to Trimethoprim/Sulfamethoxazole and Ampicillin. Stool analysis was found to be a test of high diagnostic yield. However, there is still a need for more studies on this subject with a focus on possible predictive factors for specific organisms.

Optical trapping allows manipulating very small objects – varying from Angstoms to micron size particles – without physical contact by taking advantage of laser light. This technique, relying on light momentum transfer, allows manipulating biological matter (such as cells, organelles, vesicles or chemically functionalized artificial particles, etc.) and offers promising potentialities for research in biotechnology and biochemistry. Individually confining a large number of microscopic objects opens new ways for the downscaling of analysis tools for drug screening, particles sorting and the assessment of statistical data. In particular, the combination of optical trapping with microfluidics greatly enlarges the possibilities offered by both techniques. This PhD work takes place in a research aiming at developing novel bio-analytical instrumentation relying on large arrays of optical traps compatible with microfluidic systems. The dissertation focuses on the use of micro-optics for generating extended matrices of three-dimensional optical traps capable of capturing a large number of particles within microfluidic environments. The stability of optical traps is first studied with special emphasis on the conditions present in microfluidic flows, both from a theoretical and an experimental point of view, and trapping forces achievable on biological cells are investigated. A multiple optical trapping system relying on microlens arrays, adapted to work on commercial microscopes, is shown to be capable of generating arrays of more than 500 three-dimensional traps. Simultaneously trapping in multiple planes is also evidenced using matrices of microlenses, thanks to a self-imaging effect of the array of traps. Furthermore, possibilities offered by multiple optical trapping within microfluidic environments are explored. Polystyrene spheres as well as biological particles, such as native vesicles, can be trapped in arrays, manipulated inside microfluidic devices and analyzed in parallel through fluorescence microscopy while extremely small quantities of chemical reagents are flown past the array. Finally, for the sake of system miniaturization and further extension of the number of traps, multiple three-dimensional optical trapping based on arrays of miniaturized high numerical aperture parabolic mirrors is proposed, allowing the optics necessary for optical trapping, fluorescence excitation and collection to be integrated at the level of a microfluidic chip. Such miniaturized mirror matrices did not even exist before this thesis; their fabrication and characterization are detailed in this dissertation.

Background: Intestinal Parasitic Infections (IPIs) are major public health problems, mainly affecting school children.One of the sustainable development goals of the United Nations is to control the transmission of IPIs and the modification of possible risk factors.Objectives: To estimate the frequency and risk factors of intestinal parasitic infections among primary school children in Al Qurain district, Sharkia Governorate.Methods: a cross-sectional study was conducted on 320 primary school children.Participants' data regarding socio-demographic characteristics, behavioral health habits, and complaints assessment questions were collected via semi-structured questionnaire.Stool samples were collected from students by the aid of their mothers and examined in the family medicine center.Results: The study revealed that one third (35%) of studied children had a parasitic infection.The highest percentage (44.4%) of infected children had E.histolytica.Children aged 9-12 years, with low mothers' and fathers' education, large family size, and low social class are more likely to had IPIs.The study found a statistically significant association between all behavioral health habits, all clinical manifestations, and parasitic infection.Conclusion: The results of the study reflect a relatively high prevalence rate of parasitic infections demands improved health education on regular hand washing, usage of toilet paper, washing fruits and vegetables, not eating outdoors, and avoid walking barefoot.

Purpose: Clostridium difficile infection has been associated with several types of antibiotics, including fluoroquinolones. The incidence of C difficile infection related to the nonabsorbed antibiotic rifaximin is unknown. Rifaximin is approved for the treatment of travelers' diarrhea caused by noninvasive strains of Escherichia coli and is being investigated for the treatment of hepatic encephalopathy (HE). This retrospective study evaluated the incidence of C difficile infection in patients with cirrhosis who received rifaximin for treatment of HE in community and university gastroenterology practices. Methods: Medical charts for all patients diagnosed with cirrhosis who received oral rifaximin for the treatment of HE between January 2004 and May 2008 were reviewed; patients had been treated at 1 university practice and 3 community practices. Patients who developed diarrhea (>6 bowel movements/d) during treatment with rifaximin were included in the analyses. Stool samples had been analyzed by cytotoxin assay testing to determine if diarrheal symptoms (ie, markedly increased stool frequency and decreased stool viscosity) were due to C difficile infection. Results: Analyses included 212 patients with cirrhosis who received rifaximin for the treatment of HE. The mean dose of rifaximin was 1055 mg/d (range, 600–1600 mg/d) for a mean duration of 250 days (range, 180–385 d). Of the 212 patients who received rifaximin, 155 were treated in a university practice and 57 were treated in community practices; 97% of patients had been diagnosed with grade 2 or 3 HE. Eighteen patients (8%) developed diarrhea during rifaximin treatment; 13 were male and 5 were female (mean age, 52 y). Twelve of the 18 patients (67%) who developed diarrhea had received treatment in the university setting and the remaining 6 (33%) had received treatment in community practices. Stool cytotoxin test results were negative for C difficile in all 18 of these patients. Diarrheal symptoms resolved in all cases with standard therapy administered after stool analyses had excluded infection. Conclusion: These findings suggest that long-term treatment with rifaximin was not associated with the development of C difficile infection in patients with cirrhosis who received rifaximin for treatment of HE. Therefore, rifaximin does not appear to increase risk of C difficile infection. Further investigations of the incidence of C difficile infection in patients who receive rifaximin are warranted.

Introduction: Chronic diarrhea is defined as the passage of soft or watery stool more than three times per day with or without blood and/or mucous or the passage of stool of more than 200 g per day and lasts for more than 4 weeks. Studies exploring the causes of chronic diarrhea in the developing countries are scarce and might not be generalizable from one setting to another. Aim: The aim of the study is to study the colonic and terminal ileal macroscopic and mucosal histopathological findings in chronic large bowel diarrhea patients. Methods: Eighty-six patients with chronic large bowel diarrhea were included after negative HIV status, stool analysis, and stool culture. A full-length colonoscopy with terminal ileoscopy was done. When the colon was within normal limits, randomly four biopsies each were taken from terminal ileum, ascending colon, transverse colon, and rectosigmoid region, respectively. Results: In a total of 86 patients, most of the patients (48%) were in the age group of 41–60 years. Females predominated in the present study in the ratio of 3:2. Ileal intubation was possible in all (100%) cases. Histology is normal in 35 patients. Fifty-one patients had histological changes of which 22 were diagnostic for specific disease which altered the treatment. Among 22 patients, 21 (95.4%) had histological changes in ascending colon and only 9 (40.9%) had changes in biopsy from rectosigmoid. In our study, definite diagnostic histology was obtained in 25.5% of cases. Conclusion: The yield of colonoscopy and biopsy in chronic large bowel diarrhea is moderate. Colonoscopy and biopsy have higher diagnostic yield than sigmoidoscopic biopsies.

IntroductionFebrile seizures are one of the most common diseases that physicians encounter in pediatric emergency departments. Two important aspects of managing patients presenting with a febrile seizure are meningitis exclusion and co-infection investigation. This study was designed to determine any infection that occurs concomitantly with a febrile seizure episode and also to assess the frequency of meningitis among children presenting with febrile seizures.MethodsThis retrospective cross-sectional study was conducted at the Children’s Medical Center, an Iranian pediatric referral hospital. All patients aged 6 months to 5 years presenting with febrile seizures from 2020 to 2021 were included. Patients’ data were collected from the medical report files. The presence of respiratory, gastrointestinal, and urinary infections was evaluated. Moreover, the detection of SARS-CoV-2 using reverse transcription polymerase chain reaction (RT-PCR) was performed for suspicious cases.The results of urine and stool analysis, as well as blood, urine, and stool cultures were checked. The frequency of lumbar puncture (LP) performance and its results were studied. The relationship between white blood cells (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein in meningitis was evaluated.ResultsA total of 290 patients were referred to the Children’s Medical Center, Tehran, Iran, due to fever and seizures. The mean age of the patients was 21.5 ± 13.0 months, and 134 (46.2%) were female. Out of 290 patients, 17% presented with respiratory infections. Nasopharyngeal SARS-CoV-2 RT-PCR was requested for 50 patients (17%), of which nine (3%) were reported positive and two patients had multi-inflammatory syndrome in children (MIS-C). Fever without local signs, gastroenteritis, and urinary tract infections were found in 40%, 19%, and 14% of the patients, respectively. LP was requested for 97 participants (33.4%) to evaluate central nervous system infection, of which 22 cases were suggestive of aseptic meningitis. Among laboratory tests, leukocytosis was significantly related to aseptic meningitis (odds ratio = 11.1, 95% CI = 3.0- 41.5). The blood culture testing result was positive in seven patients; all of them were due to skin contamination.ConclusionEvaluation of patients for possible meningitis is necessary for febrile seizure management. Although the prevalence of bacterial meningitis in these patients is not high, according to this study and other studies conducted in Iran, aseptic meningitis, especially after Measles, Mumps, and Rubella (MMR) vaccination should be considered. Leukocytosis and increased CRP can predict the occurrence of aseptic meningitis in these patients. However, further studies with a larger sample size are highly recommended. Moreover, during the COVID-19 pandemic, it is recommended to pay attention to an acute COVID-19 infection or evidence of MIS-C in children with fever and seizure.

Purpose:Trichuris trichiura is the third most common roundworm worldwide, with more than one fourth of the world's population carrying this parasite. The diagnosis is made primarily by stool examination for eggs. Colonoscopic diagnosis is rare, with less than 20 cases reported in the literature. Case: A 73 year Nepalese male presented to the outpatient endoscopy unit for evaluation of nonspecific generalized abdominal pain and normocytic anemia. He had no associated nausea, vomiting, weight loss or change in bowel pattern. The patient had immigrated to the United States about one year earlier. His laboratory data was significant for normocytic anemia without eosinophilia. Upper endoscopy revealed chronic gastritis but was otherwise unremarkable. Colonoscopy revealed a solitary worm, found in the cecum, with ova characteristic of Trichuris trichiura. The patient was treated with albendazole 400mg daily for three days. Follow-up two months after treatment revealed improvement in symptoms. Discussion:Trichuris trichiura affects more than 800 million people worldwide. The majority of cases in the United States are found within the immigrant population. The mode of transmission is primarily fecal-oral or accidental ingestion of eggs, which are usually found on dry goods such as beans, rice or grains. Upon ingestion of eggs, larvae hatch and develop in the small intestine and then migrate into the right colon. Adult worms live in the cecum and ascending colon. The anterior portion of the adult worm embeds in the mucosa, whilst the posterior portion hangs in the lumen and mates with neighboring worms. It takes approximately 60 days for a gravid female worm to shed eggs. Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The lifespan of adult worms is between 1-3 years. Diagnosis is primarily by stool examination; however it is important to note that stool analysis can be negative if examined within 2-3 months of acquiring infection. Clinical presentations can include non-specific abdominal pain, colonic obstruction, perforation, gastrointestinal hemorrhage or rectal prolapse, with laboratory findings of anemia or eosinophilia. Patients with light infestation can be asymptomatic. Colonoscopic findings of worms in the right colon (cecum and ascending colon) generally reflect a light burden, while worms found in the left colon (descending, sigmoid colon and rectum) reflect heavy burden. Irrespective of infection burden, treatment is recommended. The treatment options are albendazole 400mg once daily for 3 days, or mebendazole 100mg twice daily for 3 days.

261 Infant hematemesis: a challenging diagnosis, postnatal CMV infection or non IgE-mediated cow’s milk protein allergy? A two case report comparison

The article is devoted to the study of ultrasonic agglomeration of PM 2.5 in homogeneous and inhomogeneous ultrasonic fields. The possibility of increasing the efficiency of ultrasonic agglomeration by initiating acoustic streams in a resonant inhomogeneous ultrasonic field is shown. A inhomogeneous ultrasonic field with zones of high and low sound pressure levels formed using a bending-oscillating disk transmitter made it possible to initiate acoustic vortex-type streaming that promotes the movement of particles into the nodal areas of a standing wave and between them. Due to the formation of a inhomogeneous ultrasonic field, the efficiency of particle collection is increased: for PM 2.5, the efficiency reaches 95%; PM 1.5—92%; PM 0.5—85%. The results were obtained under the following conditions: concentration 2 × 10−2 g/m3, sound pressure level 165 dB, flow rate 6.2 m3/h. For comparison, when a homogeneous ultrasonic field is formed in the agglomeration chamber (under similar conditions), the efficiency of particle capture by inertial gas cleaning equipment does not exceed the following: for PM 2.5—89%; PM 1.5—85%; and PM 0.5—76%. The obtained research results made it possible to propose a design for an agglomeration chamber that can greatly increase the productivity of ultrasonic flow processing.

Two hundred eighty-five primary schoolgirls from the urban area of Thugba, Al-Khobar, in the Eastern Province of Saudi Arabia were examined anthropometrically. Hemoglobin estimations and laboratory...

Background: Intestinal parasitic infections (IPIs) can result in high morbidity and mortality, particularly in immunocompromised patients. Intestinal parasitic infections rate among hemodialysis Sudanese patients studied infrequently. Our paper aimed to examine and determine the prevalence of intestinal parasites among hemodialysis Sudanese patients. Methods: Stool samples were collected from Sudanese patients at a hemodialysis center in Kosti city, White Nile state, Sudan. All stool samples were examined to detect the type of parasites and determine the prevalence using the formol-ether concentration technique and Modified Zeihl Neelsen (ZN) stain technique. Results: The overall prevalence of Intestinal parasitic infections among hemodialysis using the formol-ether concentration technique and Modified Zeihl Neelsen (ZN) stain technique was (28.6%) and (44.6%) respectively. The total prevalence of parasites detected by formol-ether concentration technique; Giardia lamblia (46.9%), Entamoeba histolytica (12.5%), Entamoeba coli (40.6%), and by modified ZN staining technique; Cryptosporidium species (28%) and Isospora belli (8%). The prevalence of IPIs was higher among males than females (74 vs. 26%, respectively; P>0.05) Conclusions: Studying the prevalence of IPIs among hemodialysis Sudanese patients, may predict their health status and lead to better diagnosis and treatment. Health education and personal hygiene were recommended to reduce the transmission of parasitic diseases. This is a first descriptive study of IPIs among hemodialysis in the area of study.

Research on microfluidic devices for biological analysis has progressed sufficiently to be developed into point-of-care diagnostics products. The goal of this thesis is to improve multiple aspects of capillary-driven microfluidic devices. In particular, the objective is to provide devices with a fast time to result, that are simple to use (one-step), that can be portable, that accept a variety of samples, that operate reliably, that provide a range of detection signals, that are mass manufacturable at lost cost, and that are able to detect medically relevant biological molecules. First, we survey the evolution of microfluidic research into portable medical diagnostic devices. By looking at several gaps and opportunities in current medical diagnostics, we provide an overview of research topics that have the potential to shape the next generation of point-of-care diagnostics. Specifically we explain technologies in the order of sample interacting with different components of a device. We investigate the materials, surface treatments, sample processing, microfluidic elements (such as valves, pumps and mixers), receptors and analytes and the integration of these components into a device that might conceivably leave the laboratory for the hands of consumers. The knowledge of what is important in a point-of-care diagnostics device was used to develop a proof of concept. One of the main challenges is to make microfluidics easy to use by incorporating reagents and microfluidic elements. We integrated a number of functional elements on a chip such as a sample collector, delay valves, flow resistors, a deposition zone for detection antibodies (dAbs), a reaction chamber sealed with a polydimethylsiloxane (PDMS) substrate, and a capillary pump and vents. We further incorporated capture antibodies (cAbs), detection antibodies (dAbs) and analyte molecules for making one-step immunoassays. The integrated microfluidic chip requires only the addition of sample to trigger a sequence of events controlled by capillary forces to detect C-reactive protein (CRP), a general inflammation and cardiac marker, at a concentration of 1 ng mL-1 within 14 min using only 5 µL of human serum. The proof-of-concept is extended to easily modify several assay parameters such as the flow rates and the volumes of samples for tests, and the type of reagents and receptors for analytes. The multiparametric microfluidic chip is capable of analyzing 20 µL of human serum in 6 parallel flow paths in a range of flow rates with filling times from 10 minutes to 72 minutes. The asymmetric release of dAbs in a stream of human serum is compensated by a Dean flow mixer. Sample is equally split into 6 reaction chambers connected to flow resistances that vary flow rates, and the kinetics of capture of analyte-dAb complexes. The increased incubation time leads to a fourfold increase in detection signal in the reaction chamber with the longer incubation time. Furthermore, integrating reagents and controlling their release is essential for simple and accurate point-of-care diagnostic devices. We developed reagent integrators (RIs) to release small amounts of dried reagents (ng quantities and less) into microliters of sample. Typical RIs are composed of an inlet splitting into a central reagent channel, with a high hydraulic resistance, and two diluter channels. Reagents spotted in the central channel reconstitute in sample during filling and merge at the end of the RI with a dilution factor corresponding to the relative hydraulic resistance of the channels forming the RI. RIs are simple to integrate in lateral flow assays and provide a great degree of control over reagent integration and dissolution. Finally, the one-step capillary-driven microfluidic chips have the ability to not only detect a variety of proteins, but also to detect nucleic acids for molecular diagnostics. These devices, especially if manufactured in low cost plastic and used with portable fluorescence readers, have the potential to identify a wide variety of health conditions and to enable truly decentralized medical diagnostics.

Systemic chemotherapy has shown a significant survival benefit in patients with hepatocellular carcinoma (HCC). However, it is associated with various immune-related adverse events (irAEs). We report a case with grade 3 diarrhea and grade 2 colitis following systemic chemotherapy, successfully treated with prednisolone. An 89-year-old man was incidentally detected with a 140-mm hypervascular intrahepatic nodule on contrast-enhanced computed tomography (CECT). Washout of the contrast medium was also detected, and protein induced by vitamin K deficiency or antagonists-II (PIVKA-II) was elevated. Since the Albumin–Bilirubin (ALBI) grade was 2a without any distant metastasis, transarterial chemoembolization (TACE) was performed to treat the HCC, but several intrahepatic nodules were seen in both lobes. Therefore, the patient was treated with lenvatinib for 1 year and 4 months. A complete response according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria was achieved in 2 months; however, multiple hypervascular nodules were detected again. Since the ALBI grade was 1, a second round of chemotherapy with atezolizumab and bevacizumab was initiated. Although a complete response was achieved, the therapy was discontinued due to grade 3 diarrhea and grade 2 colitis after the sixth course. Based on the stool analysis and culture, CECT, and colonoscopy, the diagnosis was atezolizumab-associated colitis. Diarrhea was controlled following the oral administration of 0.5 mg/kg/day of prednisolone, and atezolizumab-bevacizumab therapy was successfully reinitiated without recurrence of colitis. The management of irAEs is important for a significant survival benefit. Systemic chemotherapy with atezolizumab and bevacizumab can be resumed despite a grade 3 irAE due to atezolizumab.