Host and Environmental Correlates of Multi-Drug Resistance in Kenyan Children with Acute Bacterial Diarrhea

Thesis (Master's)--University of Washington, 2016-06

Arousal and re-feeding rapidly restores digestive tract morphology following aestivation in green-striped burrowing frogs

During aestivation, the gut of the green-striped burrowing frog, Cyclorana alboguttata undergoes significant morphological down-regulation. Despite the potential impact such changes might have on the re-feeding efficiency of these animals following aestivation, they appear to be as efficient at digesting their first meals as active, non-aestivating animals. Such efficiency might come about by the rapid restoration of intestinal morphology with both arousal from aestivation and the initial stages of re-feeding. Consequently, this study sought to determine what morphological changes to the intestine accompany arousal and re-feeding following 3 months of aestivation. Arousal from aestivation alone had a marked impact on many morphological parameters, including small and large intestine masses, small intestinal length, LF heights, enterocyte cross-sectional area and microvilli height and density. In addition, the onset of re-feeding was correlated with an immediate reversal of many morphological parameters affected by 3 months of aestivation. Those parameters that had not returned to control levels within 36 h of feeding generally had returned to control values by the completion of digestion (i.e. defecation of the meal). Re-feeding was also associated with several changes in enterocyte morphology including the incorporation in intracytoplasmic lipid droplets and the return of enterocyte nuclear material to the 'active' euchromatin state: In conclusion, morphological changes to the gut of aestivating frogs which occur during aestivation are transitory and rapidly reversible with both arousal from aestivation and re-feeding. The proximate causes behind these transitions and their functional significance are discussed. (C) 2005 Elsevier Inc. All rights reserved.

Ecosystem Structure and Function Still Altered Two Decades After Short-Term Fertilization of a Seagrass Meadow

An oligotrophic phosphorus (P) limited seagrass ecosystem in Florida Bay was experimentally fertilized in a unique way. Perches were installed to encourage seabirds to roost and deliver an external source of nutrients via defecation. Two treatments were examined: (1) a chronic 23-year fertilization and (2) an earlier 28-month fertilization that was discontinued when the chronic treatment was initiated. Because of the low mobility of P in carbonate sediments, we hypothesized long-term changes to ecosystem structure and function in both treatments. Structural changes in the chronic treatment included a shift in the dominant seagrass species from Thalassia testudinum to Halodule wrightii, large increases in epiphytic biomass and sediment chlorophyll-a, and a decline in species richness. Functional changes included increased benthic metabolism and quantum efficiency. Initial changes in the 28-month fertilization were similar, but after 23 years of nutrient depuration T. testudinum has reestablished itself as the dominant species. However, P remains elevated in the sediment and H. wrightii has maintained a presence. Functionally the discontinued treatment remains altered. Biomass exceeds that in the chronic treatment and indices of productivity, elevated relative to control, are not different from the chronic fertilization. Cessation of nutrient loading has resulted in a superficial return to the pre-disturbance character of the community, but due to the nature of P cycles functional changes persist.

Free-Floating Thrombi in the Right Atrium Causing Pulmonary Embolism

A 74-year-old man presented to our Emergency Department with acute dyspnoea. His electrocardiogram showed atrial flutter with 2:1 block and a rate of 150 bpm. Initial investigations revealed a D-dimer level of 6.01 mg/dl. Based on the patient’s complaints and the high D-dimer level, computed tomography pulmonary angiography was immediately performed. This showed no evidence of pulmonary embolism, but there were pneumatic changes in the right upper lung lobe. Antibiotics treatment was started with pipracillin/tazobactam, after which the patient’s condition improved. However, on the third day after admission he developed acute dyspnoea, diaphoresis and cardiopulmonary instability immediately after defecation. To promptly confirm our clinical suspicion of pulmonary embolism, a transthoracic echocardiography was carried out. This demonstrated a worm-like, mobile mass in the right heart. The right ventricle was enlarged, and paradoxical septal motion was present, indicating right ventricular pressure overload. The systolic tricuspid valvular gradient was 56 mmHg. The patient was treated with thrombolysis. His condition was greatly clinically improved after 3 hours. After 10 days of hospitalization, the patient was discharged.

Frequency and molecular characterisation of Entamoeba histolytica , Entamoeba dispar , Entamoeba moshkovskii , and Entamoeba hartmanni in the context of water scarcity in northeastern Brazil

This study aimed to estimate the frequency, associated factors, and molecular characterisation of Entamoeba histolytica , Entamoeba dispar, Entamoeba moshkovskii , and Entamoeba hartmanni infections. We performed a survey (n = 213 subjects) to obtain parasitological, sanitation, and sociodemographic data. Faecal samples were processed through flotation and centrifugation methods. E. histolytica, E. dispar, E. moshkovskii, and E. hartmanni were identified by nested-polymerase chain reaction (PCR). The overall prevalence of infection was 22/213 (10.3%). The infection rate among subjects who drink rainwater collected from roofs in tanks was higher than the rate in subjects who drink desalinated water pumped from wells; similarly, the infection rate among subjects who practice open defecation was significantly higher than that of subjects with latrines. Out of the 22 samples positive for morphologically indistinguishable Entamoeba species, the differentiation by PCR was successful for 21. The species distribution was as follows: 57.1% to E. dispar, 23.8% to E. histolytica, 14.3% to E. histolytica and E. dispar, and 4.8% E. dispar and E. hartmanni. These data suggest a high prevalence of asymptomatic infection by the group of morphologically indistinguishable Entamoeba histolytica/dispar/moshkovskii complex and E. hartmanni species. In this context of water scarcity, the sanitary and socioenvironmental characteristics of the region appear to favour transmission.

Clinical Practice Guideline: irritable bowel syndrome with constipation and functional constipation in the adult

In this Clinical Practice Guideline we discuss the diagnostic and therapeutic approach of adult patients with constipation and abdominal complaints at the confluence of the irritable bowel syndrome spectrum and functional constipation. Both conditions are included among the functional bowel disorders, and have a significant personal, healthcare, and social impact, affecting the quality of life of the patients who suffer from them. The first one is the irritable bowel syndrome subtype, where constipation represents the predominant complaint, in association with recurrent abdominal pain, bloating, and abdominal distension. Constipation is characterized by difficulties with or low frequency of bowel movements, often accompanied by straining during defecation or a feeling of incomplete evacuation. Most cases have no underlying medical cause, and are therefore considered as a functional bowel disorder. There are many clinical and pathophysiological similarities between both disorders, and both respond similarly to commonly used drugs, their primary difference being the presence or absence of pain, albeit not in an "all or nothing" manner. Severity depends not only upon bowel symptom intensity but also upon other biopsychosocial factors (association of gastrointestinal and extraintestinal symptoms, grade of involvement, and perception and behavior variants). Functional bowel disorders are diagnosed using the Rome criteria. This Clinical Practice Guideline has been made consistent with the Rome IV criteria, which were published late in May 2016, and discuss alarm criteria, diagnostic tests, and referral criteria between Primary Care and gastroenterology settings. Furthermore, all the available treatment options (exercise, fluid ingestion, diet with soluble fiber-rich foods, fiber supplementation, other dietary components, osmotic or stimulating laxatives, probiotics, antibiotics, spasmolytics, peppermint essence, prucalopride, linaclotide, lubiprostone, biofeedback, antidepressants, psychological therapy, acupuncture, enemas, sacral root neurostimulation, surgery) are discussed, and practical recommendations are made regarding each of them.

Site and mechanism of the colokinetic action of the ghrelin receptor agonist, HM01

Background It has been recently demonstrated that the ghrelin receptor agonist, HM01, caused defecation in rats that were treated to provide a model for the constipation of Parkinson's disease. HM01 significantly increased fecal output and increased Fos activity in neurons of the hypothalamus and hindbrain, but not in the spinal defecation center. Other ghrelin agonists act on the defecation center. Methods Receptor pharmacology was examined in ghrelin receptor (GHSR1a) transfected cells. Anesthetized rats were used to investigate sites and mechanisms of action. Key Results HM01 activated rat GHSR1a at nanomolar concentrations and was antagonized by the GHSR1a antagonist, YIL781. HM01, intravenous, was potent to activate propulsive colorectal contractions. This was prevented by pelvic nerve section and by intravenous YIL781, but not by spinal cord section rostral to the defecation centers. Direct intrathecal application of HM01 to the defecation center at spinal level L6-S1 initiated propulsive contractions of the colorectum. Conclusions & Inferences HM01 stimulates GHSR1a receptors on neurons in the lumbosacral defecation centers to cause propulsive contractions and emptying of the colorectum. It has greater potency when given systemically, compared with other GHSR1a agonists.

A ghrelin receptor agonist is an effective colokinetic in rats with diet-induced constipation

Background Despite constipation being a common problem, the treatments that are available have side effects and are only partly effective. Recent studies show that centrally penetrant ghrelin receptor agonists cause defecation in humans and other species. Here, we describe some features of a rat model of low fiber-induced constipation, and investigate the effectiveness of the ghrelin agonist, capromorelin. Methods Rats were given low-fiber diets for 5 weeks. Their colorectal responsiveness to distension and to a behavioral test, water avoidance and colon histology were compared to those of rats on a standard diet. Key Results After the low-fiber diet, distension of the colon produced fewer propulsive contractions, behaviorally induced defecation was reduced, and the lining of the colorectum was inflamed. However, capromorelin was similarly effective in causing defecation in constipated and non-constipated rats. Conclusions & Inferences Low-fiber diet in rats produces a constipation phenotype, characterized by reduced responsiveness of the colorectum to distension and to a behavioral stimulus of defecation, water avoidance. The effectiveness of capromorelin suggests that centrally penetrant ghrelin receptor stimulants may be effective in treating constipation.

Physicochemical and microbial analysis of feces from horses fed diets containing citrus pulp.

This study aimed to evaluate the e ect of diets containing increasing levels of citrus pulp on the physic-chemical and microbiological characteristics of horses feces. Five mares, at an average age of 3.5 years old and body weight of 492 ± 44.5 kg were arranged in a 5 x 5 Latin Square. The experimental diet consisted of 60% coast-cross hay and 40 % of concentrate with increasing levels of citrus pulp (0, 7, 14, 21, and 28 %). To determine the fecal pH, samples were collected directly from the oor, immediately after defecation, in the rst feces the day at 07:00 a.m., and color and fecal consistency were evaluated. For microbiological analysis, an aliquot was reserved in plastic bags, frozen, and sent to the microbiological laboratory for further analysis. Lactic acid bacteria were counted for Lactobacillus spp. and Streptococcus spp. from fecal samples under anaerobic conditions. The diet produced di erences (P<0.05) in feces consistency 98% had normal and rm stools, while 2% had loose ruminant-type feces. We observed no di erence (P<0.05) for color, verifying 100% of greenish feces, normal for equines. There was no e ect (P>0.05) on pH and on the number of Lactobacillus spp. and Streptococcus spp. The inclusion of up to 28% citrus pulp concentrates for horses did not promote change in the physio-chemical characteristics and on the population of lactic acid-producing bacteria in feces.

Comportamento ingestivo de ovinos alimentados com dietas contendo sementes de urucum.

Resumo: Avaliaram-se os efeitos da inclusão dietética das sementes de urucum substituindo alimentos concentrados (milho e farelo de soja) e volumoso (feno de pasto nativo da caatinga) sobre o comportamento ingestivo de ovinos. Foram utilizados vinte ovinos machos, castrados, sem padrão racial definido (SPRD) distribuídos em um delineamento inteiramente casualizado com quatro tratamentos representados pelos níveis de inclusão das sementes de urucum (0%; 10%; 23%; 35% na matéria seca), com cinco animais por tratamento. Os animais foram submetidos à observação visual para avaliação do comportamento ingestivo, foram observados a cada cinco minutos, durante 24 horas, para determinação do tempo despendido em alimentação, ruminação e ócio. Avaliaram-se os eventos comportamentais dos ovinos: tempo de alimentação (TAL), ruminação (TRUM) e ócio (TÓCIO). Determinou-se também a mastigação merícica dos ovinos, estimando-se o número de mastigações e a quantidade de bolos ruminados por unidade de tempo, além do número médio de defecação e micção, e frequência de ingestão de água. Os dados foram analisados pelo software SAS®, tendo sido realizada a comparação das médias pelo teste Tuckey, análise dos contrastes polinomiais e ortogonais para os dados que apresentaram significância. A inclusão de sementes de urucum não influenciou os parâmetros de comportamento ingestivo e nem os padrões nictmerais (P<0,05). A substituição da fibra proveniente do feno de pasto nativo pela fibra das sementes de urucum trouxe vantagens especialmente pela melhoria das eficiências de alimentação e de ruminação. [Ingestive behavior of sheeps fed with diets containing anatto seeds]. Abstract: Evaluated the effect of dietary inclusion of annatto seeds replacing concentrate feed (corn and soybean meal) and roughage (hay of native pasture from Caatinga) on feeding behavior of sheep. Twenty male undefined breed sheep and castrated were distributed in a completely randomized design into four treatments (five animals per treatment), with the inclusion of annatto seeds in the diets at levels of 0%, 10%, 23% and 35%, in dry matter basis. The animals were submitted to visual observation in order to acess their ingestive behavior, were observed every five minutes, during 24 hours, to determine time spent on feeding, rumination and idleness. The behavioral events of the sheeps evaluated were time for feeding (TAL), time for rumination (TRUM) and time of idleness (TOCIO). The ruminating chews of the sheeps was determined, thus estimating the number of chews and quantity of ruminated boli per unit of time, the average number of defecation and urination, and frequency of water intake were also determined Data were analyzed using SAS® software and the Tukey test to comparison of means. Polynomial and orthogonal contrasts were made for data that showed significance. The inclusion of annatto seeds did not influence the parameters of feeding behavior and neither nictemerals patterns. The replacement of fiber