RESUMEN
The attraction of washed, medium-free cells of Pantoea (Enterobacter) agglomerans to wild, adult Rhagoletis mendax Curran, the blueberry maggot fly, was evaluated in managed blueberry fields in Maine. Attraction was evaluated using Pherocon AM and Ladd traps, each tested with or without washed bacterial cells. Field studies showed significant increases in fly captures on the Pherocon AM traps. Apple volatiles odors on Ladd traps seemed to cancel the effects of bacterial odors. Aerobic heterotrophic bacteria were isolated and identified from alimentary organs within wild R. mendax. Isolates indentified included P. agglomerans. Blueberries collected in the field were surveyed for the presence of P. agglomerans and blueberries containing blueberry maggot larvae and noninfested blueberries were analyzed for amino acid content. Maggot-infested blueberry contained twice the amino acid nitrogen than that of noninfested blueberry. P. agglomerans, like with other pest tephritids, seems to be a cosmopolite with blueberry maggot.
Asunto(s)
Pantoea/fisiología , Tephritidae/microbiología , Animales , Tracto Gastrointestinal/microbiologíaRESUMEN
Dose reductions of pegylated interferon alpha and ribavirin may be avoided by using growth factors. This phase II clinical trial assesses the dose, efficacy and safety of darbepoetin alpha and filgrastim for treatment of anaemia and neutropenia associated with combination therapy for hepatitis C virus (HCV). Chronic hepatitis C patients (n = 101) received pegylated interferon alpha-2b (1.5 mug/kg once weekly) and ribavirin (800-1400 mg once daily). Patients with anaemia [haemoglobin (Hb) /= 0.75 x 10(9)/L and <10 x 10(9)/L. During antiviral therapy, 52% of patients required darbepoetin alpha, filgrastim or both. Hb at the time of darbepoetin alpha initiation was 10.2 +/- 0.4 g/dL. After 81 days of darbepoetin alpha, Hb increased by 1.9 +/- 1.0 g/dL to 12.1 +/- 1.1 g/dL (P < 0.0001). Filgrastim resulted in a significant increase in ANC [0.75 +/- 0.16 x 109/L to 8.28 +/- 5.67 x 10(9)/L (P < 0.0001)]. In treatment-naïve patients, 48% achieved sustained virological response (SVR), whereas 27% of patients previously treated with a course of pegylated interferon alpha achieved SVR. Low viral load, nongenotype 1 and treatment with growth factors were independently associated with SVR. Mild and severe anaemia were associated with quality of life impairments. Darbepoetin alpha resulted in an improvement in the Vitality domain of Short Form-36. No significant adverse events were related to growth factors. During anti-HCV therapy, filgrastim improved neutropenia and darbepoetin alpha improved both anaemia and quality of life. Future randomized clinical trials are needed to establish the impact of growth factors in improving sustained virological response.
Asunto(s)
Anemia/tratamiento farmacológico , Eritropoyetina/análogos & derivados , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Hematínicos/administración & dosificación , Hepatitis C Crónica/complicaciones , Neutropenia/tratamiento farmacológico , Adulto , Anemia/psicología , Antivirales/efectos adversos , Antivirales/uso terapéutico , Darbepoetina alfa , Eritropoyetina/administración & dosificación , Eritropoyetina/efectos adversos , Eritropoyetina/farmacología , Femenino , Filgrastim , Factor Estimulante de Colonias de Granulocitos/efectos adversos , Factor Estimulante de Colonias de Granulocitos/farmacología , Hematínicos/efectos adversos , Hematínicos/farmacología , Hemoglobinas/análisis , Hepatitis C Crónica/tratamiento farmacológico , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Interferón-alfa/uso terapéutico , Masculino , Persona de Mediana Edad , Polietilenglicoles , Calidad de Vida , Proteínas Recombinantes , Ribavirina/administración & dosificación , Ribavirina/uso terapéutico , Resultado del Tratamiento , Carga ViralRESUMEN
Many patients suffering from long-term psychiatric illness are on medication for long periods. These medications frequently cause xerostomia leading to an increased risk of caries, gingivitis, periodontitis and stomatitis. Oral hygiene is therefore of the utmost importance for these patients. Nurses interact with patients on a daily basis, and therefore they are the psychiatric caregivers of choice to support these patients. The main aim of this study was to describe the oral health status of patients in short-term and long-term psychiatric care by means of oral assessment. A second aim was to discover whether the assessment guide used could distinguish any differences between these two groups. A modified version of the Oral Assessment Guide (OAG) developed by Eilers et al. (1988) was used. In addition, new items/categories were developed, forming the Oral Assessment Guide for Psychiatric Care (OAG-PC). A total of 57 patients in psychiatric care, short-term (n = 32) and long-term (n = 25), were assessed by the OAG-PC. Patients in long-term psychiatric care had significantly higher scores on the total OAG-PC compared with those in short-term psychiatric care, indicating a worse oral health status. Statistically significant differences were also found in relation to the following OAG-PC categories: odour from the mouth, mucous membranes, gums, teeth or dentures, calculus on teeth and appearance of teeth. Further research should be focused on the difficulties for nurses in approaching their patients in order to perform oral care and on evaluating the effect of teaching and training psychiatric nurses in oral care, preferably with the assistance of the OAG-PC. This assessment guide may thereby also be valuable for nurses' documentation in estimating, planning, implementing and evaluating their psychiatric patients' oral care needs.
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Trastornos Mentales/enfermería , Enfermedades de la Boca/enfermería , Salud Bucal/normas , Enfermería Psiquiátrica/métodos , Antipsicóticos/efectos adversos , Femenino , Estado de Salud , Humanos , Masculino , Trastornos Mentales/tratamiento farmacológico , Enfermedades de la Boca/inducido químicamente , Evaluación en EnfermeríaRESUMEN
There are a number of models, both analytical and Monte Carlo, which are used to describe the fluence from the treatment head of accelerators. One common problem in these simulations is to find relevant information about details in the treatment head. A complex unit in the treatment head for which reliable data is seldom given is the monitor chamber. In this work two methods are described for obtaining this information by analyzing the increased scattering of an electron beam when the monitor chamber is introduced in the beam. It was found that the effective thickness of the electrodes in a monitor chamber can be determined with sufficient accuracy by using experimental results combined with Fermi-Eyges theory or Monte Carlo simulations.
Asunto(s)
Aceleradores de Partículas/instrumentación , Radiometría/instrumentación , Fenómenos Biofísicos , Biofisica , Electrones/uso terapéutico , Humanos , Modelos Teóricos , Método de Montecarlo , Radioterapia de Alta Energía , Dispersión de RadiaciónRESUMEN
The influence of the electron contamination at in vivo dosimetry with diodes on the patient surface has been investigated by introducing different accessories in the beam path and by changing the field size and SSD. The results show a clear correlation between the electron contamination at an effective measuring depth of the diode and the signal from the patient diode. When the electron contamination is taken into account the agreement between the diode values and the absorbed dose is greatly improved. More accurate in vivo dosimetry with less error margins is therefore possible if better predictions of the electron contamination in high-energy photon beams can be performed.
Asunto(s)
Electrones , Fotones/uso terapéutico , Radiometría , Radioterapia de Alta Energía , Fenómenos Biofísicos , Biofisica , Humanos , Neoplasias/radioterapia , Aceleradores de Partículas , Radiometría/instrumentación , Radiometría/métodos , Radiometría/estadística & datos numéricos , Dosificación Radioterapéutica , Semiconductores , Tecnología RadiológicaRESUMEN
The role of sensory afferents in inflammation-induced alterations in myoelectric activity in vivo was investigated in the rabbit small intestine. Isolated ileal loops were implanted with serosal electrodes and exposed to ricin or vehicle after pretreatment with 125 mg/kg of subcutaneous (125 mg over 3 days) or intraluminal (640 microM) capsaicin. After 5 h of myoelectric recording, the loops were prepared for histology and for ex vivo generation of eicosanoids. Capsaicin exacerbated mucosal damage after exposure to ricin but did not alter neutrophil infiltration. Subcutaneous capsaicin alone elevated slow-wave frequency and spike events and transiently suppressed the myoelectric response to ricin. In contrast, intraluminal capsaicin alone did not alter myoelectric activity but produced a sustained inhibition of the response to ricin. Eicosanoid production was unchanged by capsaicin alone. Intraluminal capsaicin blocked increases in leukotriene C4 and prostaglandin E2 during inflammation, an effect that paralleled its inhibition of myoelectric activity. Thus the contribution of sensory afferents to altered motility during acute ileitis involves the release of mucosal inflammatory mediators that influence neural control of smooth muscle.
Asunto(s)
Ileítis/fisiopatología , Íleon/fisiopatología , Músculo Liso/fisiopatología , Neuronas Aferentes/fisiología , Enfermedad Aguda , Animales , Capsaicina/farmacología , Eicosanoides/biosíntesis , Electrofisiología , Ileítis/inducido químicamente , Ileítis/metabolismo , Íleon/metabolismo , Íleon/patología , Técnicas In Vitro , Masculino , Músculo Liso/metabolismo , Músculo Liso/patología , Conejos , RicinaRESUMEN
BACKGROUND AND PURPOSE: The normalisation depth for determination of output factors in photon fields has frequently been the depth of dose maximum. At high energies the contribution from contaminating electrons is significant at dose maximum and is critically dependent on the beam geometry parameters, which is why a larger depth should be preferred. MATERIALS AND METHODS: The effect of electron contamination was studied using a purging magnet to remove charged particles from the treatment head and a helium bag to minimise production between the head and the phantom. RESULTS: A depth of 10 cm was found to be beyond the range of the contaminating electrons for photon energies up to 20 MV (TPR(20)(10) = 0.772). However, at 50 MV (TPR(20)(10) = 0.810) contaminating electrons contribute 2-3% to the absorbed dose at 10 cm depth. CONCLUSIONS: 10 cm is recommended as both reference and normalisation depth for all megavoltage photon beam qualities, i.e. 60Co and X-rays from accelerators up to 50 MV.
Asunto(s)
Fotones , Radioterapia de Alta Energía/métodos , Calibración , Relación Dosis-Respuesta en la Radiación , Electrones , Dosificación RadioterapéuticaRESUMEN
BACKGROUND AND PURPOSE: Output factors are generally measured with cylindrical ionization chambers. It was investigated if Si-diodes of p-type instead could be used. The advantage would be the small detector size and the robust construction of the detector. MATERIALS AND METHODS: Two types of diodes were studied, one with a shielding layer of tungsten specially made to reduce the excess response for scattered photons and one standard diode without any extra shielding. The measurements were performed at accelerating potentials between 4 and 50 MV and beam sizes between 4 cm x 4 cm and 40 cm x 40 cm. RESULTS: The results showed that both types of diodes are suitable for measurements of head scatter factors in mini-phantoms. However, the diodes were found inappropriate for measurement of output factors for large fields in extended water phantoms. For small fields (<10 cm x 10 cm) a small detector is advantageous and no errors due to the scatter contribution were seen. CONCLUSIONS: An cylindrical ionization chamber is the best choice for output factor measurements in extended water phantoms for large field sizes while diodes are an alternative in small fields. There were negligible differences between the detectors in head scatter measurements in mini phantoms.
Asunto(s)
Planificación de la Radioterapia Asistida por Computador/instrumentación , Humanos , Protección Radiológica , Radioterapia/métodos , Dispersión de Radiación , TungstenoRESUMEN
Gastrointestinal involvement occurs in most patients with systemic sclerosis and is subclinical in about one third. Early pathology is characterized by vasculopathy, resulting in tissue ischemia and progressive dysfunction. Noninvasive esophageal studies using semisolid bolus scintigraphy are sensitive but lack specificity. Long-term treatment of reflux with high-dose proton pump inhibitors appears safe and effective for symptom relief and may prevent recurrence of esophagitis and stricture. Dyspepsia may result from gastroparesis and antral distension. Gastric antral vascular ectasia is a vascular manifestation, and bleeding may be controlled endoscopically. Prokinetic agents effective in pseudoobstruction include metoclopramide, domperidone, cisapride, octreotide, and erythromycin. Patients with intestinal neuropathy or response to bolus octreotide are more probable long-term responders. The combination of octreotide and erythromycin may be particularly effective in systemic sclerosis. The combination of cisapride and erythromycin may cause serious cardiac arrhythmia and is contraindicated. Omeprazole may predispose to small intestinal bacterial overgrowth. Malabsorption not responding to antibiotic therapy should be investigated with small-bowel biopsy to rule out more unusual causes. Pneumatosis cystoides intestinalis may be due to excessive hydrogen production by intestinal bacteria altering the partial pressure of nitrogen in the intestinal wall. In selected cases, surgery for intestinal failure is an option with resection or bypass of affected segments or placement of enterostomy tubes for feeding or decompression. Careful preoperative characterization of intestinal segments is required.
Asunto(s)
Enfermedades Gastrointestinales/etiología , Esclerodermia Sistémica/fisiopatología , Enfermedades del Esófago/etiología , Enfermedades Gastrointestinales/patología , Enfermedades Gastrointestinales/terapia , Humanos , Enfermedades Intestinales/etiología , Esclerodermia Sistémica/patología , Esclerodermia Sistémica/terapia , Gastropatías/etiologíaRESUMEN
The electron contamination in photon beams has been investigated by means of contaminating lepton depth doses and dose profiles in different geometries with two 20 MV beams. Different components of this contamination have been investigated separately by systematically adding contamination to a "clean" reference field. At 20 MV, the air generated electrons were found to be almost negligible compared to the electrons originating from the accelerator head when measurements were performed in standard fields at SSDs between 80 and 120 cm. The total electron part of the depth dose curve was then almost the same, i.e., independent of SSD, when the collimator opening was held fixed. However, when different accessories such as a shaping block and different attenuating plates were located in the beam path below the collimators, a large SSD dependence of the electron contamination was noticed. A comparison was also made between two machines, one equipped with a multileaf collimator, with similar beam qualities at 20 MV. These measurements indicate that the interior view of the treatment head seen by the detector (mainly the flattening filter, monitor chamber, or other electron generating material) influences the magnitude of the electron contamination. When the collimator opening is decreased the electron contamination will also decrease as parts of the electron source will be shielded by the collimator blocks.
Asunto(s)
Electrones , Fotones , Radioterapia de Alta Energía/métodos , Aire , Aceleradores de Partículas , Dosis de Radiación , Radioterapia de Alta Energía/instrumentaciónRESUMEN
In vitro electrophysiological studies of ileal circular muscle from rabbits with ricin-induced inflammation were performed to investigate whether altered neural control or myogenic activity contributes to previously described changes in in vivo myoelectric activity. Ricin treatment increased mean slow-wave amplitude but not frequency or resting membrane potential. Prolonged electrical field stimulation evoked a hyperpolarization during the stimulus train and a depolarization on cessation of stimulation. In the presence of atropine, the depolarization was larger in ricin-treated tissue than in control tissue, showing that ileitis enhanced noncholinergic excitation. The nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester reduced the hyperpolarization in ricin-treated but not in control tissue, suggesting that inflammation increased nitric oxide-mediated inhibition. Substance P desensitization reduced noncholinergic excitation and mean slow-wave amplitude only in ricin-treated tissue, demonstrating that changes in these parameters during inflammation resulted from increased release of, or sensitivity to, tachykinins. These data suggest that acute ileitis alters tachykinin- and nitric oxide-mediated neurotransmission that may affect the normal pattern of ileal motility and/or sensory reflexes.
Asunto(s)
Ileítis/fisiopatología , Íleon/inervación , Músculo Liso/fisiopatología , Animales , Estimulación Eléctrica , Electrofisiología , Sistema Nervioso Entérico/fisiopatología , Ileítis/inducido químicamente , Masculino , Inhibición Neural , Óxido Nítrico/metabolismo , Sistema Nervioso Parasimpático/fisiopatología , Conejos , Ricina , Taquicininas/fisiología , Factores de TiempoRESUMEN
An in vitro system was developed to mimic conditions within normal and mastitic mammary glands. The system consisted of a modified batch fermenter that allowed for manipulation of temperature, oxygen tension, and pH. Experiments in tryptose-soy broth and UHT-treated milk were conducted to evaluate growth characteristics of Escherichia coli P4 as physical conditions were manipulated. The effect of bacterial growth on oxygen tension and pH were also evaluated. Growth of E. coli was inhibited as temperature was increased from 37 to 41 degrees C and as oxygen tension was decreased from microaerophilic to anaerobic levels. At bacterial populations > 6 log10 cfu/ml, microaerophilic cultures became anaerobic. The pH followed a similar trend; however, after a significant decrease in pH, mean bacterial populations were 7.1 log10 cfu/ml in tryptosesoy broth and 8.2 log10 cfu/ml in UHT-treated milk. This dynamic model demonstrated potential use in evaluation of growth characteristics of mammary gland pathogens in the lactating mammary gland.
Asunto(s)
Escherichia coli/crecimiento & desarrollo , Glándulas Mamarias Animales/fisiología , Mastitis Bovina/fisiopatología , Leche/microbiología , Animales , Bovinos , Medios de Cultivo , Concentración de Iones de Hidrógeno , Glándulas Mamarias Animales/microbiología , Mastitis Bovina/microbiología , Modelos Estructurales , Oxígeno/fisiología , Estadística como Asunto , TemperaturaRESUMEN
After the skin, the gastrointestinal tract is the second most common target of systemic sclerosis. The major clinical manifestations include gastroesophageal reflux, small bowel bacterial overgrowth, malnutrition, and intestinal pseudoobstruction. Treatment is symptomatic and supportive. Gastroesophageal reflux can usually be adequately managed with prokinetic drugs, omeprazole, and judicious use of antireflux surgery. If Barrett's esophagus is present, periodic endoscopic monitoring for development of dysplastic changes or adenocarcinoma is indicated. Bacterial overgrowth usually responds to rotating antibiotics and prokinetic drugs. Malnutrition and intestinal pseudoobstruction remain the major problems and often home total parenteral nutrition is required. Intestinal pseudoobstruction occurs in two phases: an early, neuropathic phase may respond to prokinetic drugs (metoclopramide, cisapride, octreotide, and erythromycin) and dietary modification (low-residue diets, vitamin supplementation). In the late myopathic phase, therapy is usually ineffective. Treatment consists of nutritional support. Careful manometric and radiographic localization of affected segments of stomach and small and large intestines may allow judicious surgical resection or venting procedures to reduce symptoms in this unfortunate group of patients.
Asunto(s)
Enfermedades Gastrointestinales/etiología , Motilidad Gastrointestinal , Esclerodermia Sistémica/complicaciones , Sistema Digestivo/patología , Sistema Digestivo/fisiopatología , Enfermedades Gastrointestinales/patología , Enfermedades Gastrointestinales/fisiopatología , Humanos , Modelos Biológicos , Esclerodermia Sistémica/patología , Esclerodermia Sistémica/fisiopatologíaRESUMEN
The inflammatory responses to intraluminal administration of the cytotoxic lectin ricin or the hapten 2,4,6-trinitrobenzenesulfonic acid in 25% ethanol were compared. Myoelectric activity was recorded from in vivo ileal loops in rabbits after administration of either agent. At the end of a 6-h study the loops were removed and prepared for histological evaluation and for ex vivo generation of leukotriene (LT) C4 and prostaglandin (PG) E2. Both agents induced significant increases in mucosal damage, polymorphonuclear leukocyte infiltration, and edema. These changes tended to be patchy in the hapten model and confluent in the ricin model. Spike burst activity and mucosal LTC4 and PGE2 generation were also enhanced significantly. Intraluminal administration of the specific LTD4 antagonist Wy-48252 1 h before either inflammagen, significantly inhibited the myoelectric response without affecting tissue morphology or eicosanoid synthesis. These data demonstrate that there is a stereotypic spike burst response to acute inflammation, which is mediated in part by LTD4.
Asunto(s)
Enteritis/inducido químicamente , Enteritis/fisiopatología , Intestinos/fisiopatología , Complejo Mioeléctrico Migratorio , Ricina , Ácido Trinitrobencenosulfónico , Enfermedad Aguda , Animales , Eicosanoides/biosíntesis , Enteritis/patología , Mucosa Intestinal/metabolismo , Intestinos/patología , Masculino , ConejosRESUMEN
Of 21 wetlands in the Minneapolis-St. Paul area that supported similar densities of Coquillettidia perturbans larvae, 7 wetlands were treated with Altosid methoprene pellets at 5.6 kg/ha on May 28, 1992, 7 were treated with Altosid XR extended residual methoprene briquets at 1 briquet/9.3 m2 in March 1992, and the final 7 remained untreated. Emergence data collected from May 28 through late August in all sites indicated pellet and briquet treatments achieved greater than 90% control.
Asunto(s)
Culicidae , Metopreno , Control de Mosquitos/métodos , Animales , Ecología , Larva , MinnesotaRESUMEN
BACKGROUND/AIMS: Enteroadherent Escherichia coli that produce Shiga-like toxins are important causes of human disease, including enterohemorrhagic E. coli-induced colitis (EHEC). The role of Shiga-like toxins in these illnesses is unclear. The aim of this study was to establish an animal model for human EHEC and to determine the role of Shiga-like toxin I (SLT-I) in this model. METHODS: E. coli strain RDEC-1 is an enteroadherent rabbit diarrheal pathogen. An isogenic variant of RDEC-1 (termed RDEC-H19A) producing high levels of SLT-I was obtained by infecting RDEC-1 with an SLT-I-converting bacteriophage. The effects of in vivo enteric infection produced in rabbits by RDEC-H19A were compared with those in uninfected and RDEC-1-infected animals. RESULTS: SLT-I-producing RDEC-H19A induced a severe, noninvasive, enteroadherent infection in rabbits. Clinically, infection with RDEC-H19A was more severe than infection with RDEC-1 and caused more serious histological lesions including vascular changes, edema, and more severe inflammation. Interleukin 1 and platelet-activating factor appear to be important inflammatory mediators to this infection. CONCLUSIONS: The illness induced by RDEC-H19A in rabbits resembled enterohemorrhagic E. coli-induced colitis of humans. SLT-I is an important virulence factor in the pathogenesis of EHEC.
Asunto(s)
Toxinas Bacterianas/toxicidad , Enterocolitis/etiología , Enterotoxinas/toxicidad , Escherichia coli/patogenicidad , Animales , Enteritis/etiología , Enterocolitis/patología , Células HeLa , Humanos , Interleucina-1/fisiología , Masculino , Factor de Activación Plaquetaria/fisiología , Conejos , Toxina Shiga IRESUMEN
The classic approach to vector control where large tracts of land are treated with an insecticide has many shortcomings. These include high cost, chemical resistance of target species to many of the widely used insecticides, a lack of public acceptance, and the detrimental effect of sprays on nontarget species. Removal trapping, the use of visual, auditory, and olfactory attractants to lure target species into small areas where they are killed, has recently received well-deserved attention as a possible alternative to the broadcast application of chemicals for vector control. We briefly review the histories of four successful removal trapping programs; Hippelates eye gnats in the United States, tsetse flies in Africa, Stomoxys calcitrans flies in Australia, and tabanids in the United States. We then review the future prospects of removal trapping and evaluate its potential as a viable method for vector control.
Asunto(s)
Vectores de Enfermedades , Control de Plagas/métodos , África , Animales , Australia , Dípteros , Humanos , Muscidae , Moscas Tse-Tse , Estados UnidosRESUMEN
Larvae of Aedes aegypti were exposed to sublethal concentrations of the insect growth regulator, methoprene, and the glycogen content of pupae and surviving adults was compared and effects on adult longevity determined. The glycogen reserves in both male and female Ae. aegypti pupae were significantly reduced as a result of methoprene exposure. The longevity of adult females was also significantly reduced, but exposure affected neither the longevity nor the glycogen content of adult males. Adult sugar feeding increased the amount of glycogen in both treated and control females. The reduced longevity of adult females from larval methoprene treatment appeared not to be directly related to reduced glycogen, but rather reflected neuroendocrine abnormalities induced by this juvenile hormone analogue.
Asunto(s)
Aedes , Glucógeno/metabolismo , Larva/metabolismo , Longevidad/efectos de los fármacos , Metopreno/farmacología , Control de Mosquitos , Animales , Femenino , Masculino , PupaRESUMEN
An analogy is made between the Persian Gulf War and its effective, high tech weaponry and future vector control program planning. Ever increasing population pressures and environmental concerns are seen as factors driving ever more selective control strategies. Developing positive public mosquito control perceptions will be a result of greater commitment to public education. Participative management and program ownership by staff in a "bottom up" environment is encouraged. The role of host attractant development is discussed as an example of proactive involvement by members.
Asunto(s)
Control de Mosquitos/tendencias , Sociedades Científicas/tendencias , Predicción , Control de Mosquitos/organización & administración , Opinión Pública , Control de Calidad , Estados Unidos , GuerraRESUMEN
Changes in ileal and colonic myoelectric activity during the course of enteric infection of rabbits with the enteropathogenic Escherichia coli strain RDEC-1 were determined and related to microbiological, histological, and clinical parameters of disease. Rabbits were grouped into early, peak, and late stages of infection based on fecal shedding of bacteria. Weight loss and an increase in prolonged spike bursts (both action potential complexes and ileal migrating action potential complexes) developed early in infection, before the onset of diarrhea. Loose stools subsequently developed coincident with maximal numbers of action potential complexes. The myoelectric responses correlated better with mucosal enteroadherence of bacteria than with luminal colonization. These data demonstrate that, in this animal model of enteroadherent bacterial infection of the intestine, changes in intestinal myoelectric activity precede the onset of clinical diarrhea. In addition, bacterial adherence to the intestinal mucosa appears to be important in eliciting the abnormal myoelectric responses.