Effect of amorphous phase separation and crystallization on the in vitro and in vivo performance of an amorphous solid dispersion.

In this study, the performance of phase separated and crystallized amorphous solid dispersions (ASDs) was evaluated by non-sink in vitro dissolution testing in fasted-state simulated intestinal fluid (FaSSIF) and in vivo in rats. The amorphous phase-separated or crystallized ASDs were prepared by mixing an ASD of the model drug celecoxib (CCX) in polyvinylpyrrolidone (PVP) with pure amorphous or micronized crystalline CCX at 20, 40, 60 or 100% of the total drug load (25:75 w/w CCX:PVP), respectively. As expected, crystallization of CCX in the ASDs generally had a negative influence on both the area under the curve of the dissolution curve (in vitro AUC) and the plasma concentration-time profile (in vivo AUC) in rats compared to the pure ASD. However, the difference between the in vivo AUC of the pure ASD and the 20% and 40% crystallized ASDs was not statistically significant, which could indicate that a low fraction of crystallization of a drug in an ASD may only have limited impact on in vivo performance and hence bioavailability. In comparison, amorphous phase separation of CCX in the ASDs did not negatively influence the in vitro AUC and in vivo AUC to the same degree as crystallization and the dissolution profiles of all the amorphous phase-separated ASDs were similar to that of the pure ASD. In fact, even though a slight decrease of in vivo AUC with increasing fraction of amorphous phase separation was observed, the 20% and 40% amorphous phase-separated ASDs were bioequivalent with the pure ASD.

Diagnostic yield of duodenal aspirate for G. lamblia and comparison to duodenal mucosal biopsies.

Our objective was to examine the diagnostic yield of duodenal aspirates for Giardia in children and compare it to results of duodenal mucosal biopsies. The results of all duodenal aspirates submitted for direct parasite examinations over a 31-month period were reviewed, as were the histological results of duodenal mucosal biopsies from these patients. In all, 161 children (89 boys; age range 0.33-18 years) were included in the study. Giardia was identified in the duodenal aspirate of 5.6% (9/161) patients and on duodenal mucosal biopsies from all nine patients. In conclusion, the 5.6% diagnostic yield of duodenal aspirates for Giardia is higher than reported in a previous study of adult patients from a similar geographical region (0.7%). The detection of Giardia on duodenal mucosal biopsies from all patients with positive duodenal aspirates brings into question the utility and cost of the latter test. Duodenal aspirates for Giardia may be unnecessary if duodenal mucosal biopsies are obtained for histological examination.

[Strongyloidosis. Part VIII. Parasitological diagnosis]. / Wegorczyca (strongyloidosis). Czesc VIII. Diagnostyka parazytologiczna.

The effectiveness and safety of the methods of detecting Strongyloides stercoralis, by passing larvae from the faeces to water, in duodenal fluid (duodenal intubation, Enterotest), in sputum and other body fluids, have been estimated. The author recommend Baermann technique for detecting S. stercoralis in individual examinations and Dancescu technique in mass field examinations. The detection of S. stercoralis larvae by the two methods ought to be checked by Fülleborn agar Petri dish technique in order to identify parasite to the species level.

The relationship between circulating and intestinal Heligmosomoides polygyrus-specific IgG1 and IgA and resistance to primary infection.

Specific serum and intestinal immunoglobulin (Ig)G1 and IgA responses to Heligmosomoides polygyrus were measured in a panel of seven inbred mouse strains which exhibit 'rapid' (<6 weeks (SWRxSJL)F1), 'fast' (<8 weeks, SJL and SWR), 'intermediate' (10-20 weeks, NIH and BALB/c) or 'slow' (>25 weeks, C57BL/10 and CBA) resolution of primary infections. Mice with 'rapid', 'fast' or 'intermediate' response phenotypes produced greater serum and intestinal antibody responses than those with 'slow' phenotypes. The F1 hybrids ((SWRxSJL)F1) of two 'fast' responder strains showed the earliest antibody response with maximum titres evident within 6 weeks of infection. There was a negative correlation between the serum IgG1 responses and worm burdens in individual mice within a number of mouse strains, and also between serum IgG1 and IgA responses and worm burdens in the 'rapid' ((SWRxSJL)F1) responder strain. The presence of IgG1 in the gut was found to be due to local secretion rather than plasma leakage. Using Western immunoblotting, serum IgG1 from 'rapid' and 'fast' responder but not 'slow' responder mice was found to react with low molecular weight antigens (16-18 kDa) in adult worm excretory/secretory products.

Comparison of duodenal with jejunal biopsy and aspirate in chronic human immunodeficiency virus-related diarrhea.

OBJECTIVES: In human immunodeficiency virus (HIV)-infected patients with chronic unexplained diarrhea, upper endoscopy with small bowel biopsy and aspirate is often performed to identify treatable pathogens. The purpose of this study was to compare the diagnostic yield of duodenal with jejunal biopsy and aspirate. METHODS: All HIV-infected patients with chronic unexplained diarrhea who were evaluated by upper endoscopy at Bellevue Hospital Center between January 1992 and January 1997 were identified. Data were collected by reviewing patient charts, endoscopy reports, and pathology records. RESULTS: During the 5-yr study period, 442 patients underwent upper endoscopy with sampling of the duodenum (N=173) or jejunum (N=269). A pathogen was identified in 123 patients (27.8%). Microsporidia was the most common organism detected (12.2%). The diagnostic yield of jejunal biopsy and aspirate was significantly higher than that obtained from the duodenum (32.3% vs 20.8%, p=0.009). Small bowel aspirates detected a pathogen in only 1.8% of patients evaluated, and there was no difference in the yield of duodenal and jejunal aspirates (1.3% vs 2.1%, p=0.7). Patients with a CD4 count of < 100 cells/mm3 were significantly more likely to have a pathogen identified than those with higher CD4 counts (38.8% vs 7.1%,p < 0.0001). CONCLUSIONS: Upper endoscopy with small bowel biopsy and aspirate identifies a pathogen in 27.8% of individuals with HIV-related chronic unexplained diarrhea. In this patient population, jejunal biopsies acquired by enteroscopy are superior to those obtained from the duodenum. Small bowel aspirates are of little value in the workup of chronic HIV-related diarrhea.

Diagnostic yield of duodenal biopsy and aspirate in AIDS-associated diarrhea.

OBJECTIVES: To evaluate the diagnostic yield of performing duodenal biopsies and aspirates in AIDS patients with chronic diarrhea. METHODS: Retrospective review of esophagogastroduodenoscopy (EGD) records from January 1993 to March 1995 to identify those patients who underwent EGD for evaluation of AIDS associated diarrhea and had a duodenal biopsy and/or aspirate. Biopsies were examined for pathogens using routine histology and special stains, viral culture, and electron microscopy. Duodenal aspirates were evaluated for ova and parasites. All patients had previous negative stool studies. Pathology laboratory charges (hospital and professional fees) for each test and charges per positive test were determined. RESULTS: Of the 57 patients included in this study, 56 had a duodenal biopsy and 42 had a duodenal aspirate. An established pathogen was identified in only 15 (26%) patients. One patient had both Mycobacterium avium complex and microsporidia. Pathogens were identified in seven patients by hematoxylin and eosin stain, in three patients by acid-fast bacillus stain, and in six patients by electron microscopy. No pathogens were identified with Gomori's methenamine silver stain (44 patients), duodenal aspirate for ova and parasites (46 patients), immunoperoxidase stains (4 patients), or viral culture (4 patients). Cryptosporidia were identified in six, microsporidia in five, Mycobacterium avium complex in three, and Giardia lamblia and adenovirus each in one patient. CONCLUSIONS: In this series, the diagnostic yield of EGD with duodenal biopsy and aspirate in AIDS associated diarrhea was low. Pathogens were identified in 26% of patients; predominantly Cryptosporidium organisms and microsporidia. The routine performance of aspiration of duodenal contents for parasite examination and staining of duodenal tissue with Gomori's methenamine silver stain for fungal identification are not recommended. One should consider obtaining tissue for electron microscopy whenever duodenal biopsies are performed. The utility of EGD in AIDS associated diarrhea may improve as more effective therapies become available.

Giardiasis. Taming this pervasive parasitic infection.

Parasitic infection due to Giardia lamblia can produce severe, disabling gastrointestinal symptoms. Outbreaks have been linked to contaminated municipal water supplies and situations involving person-to-person contact. Immunocompromised patients are especially at risk. Because microscopic examination of stool detects the parasite in only about half of infected patients, use of enzyme-linked immunosorbent assay to detect Giardia-specific antigen is becoming increasingly popular. In most patients, therapy with quinacrine (Atabrine) hydrochloride, metronidazole (Flagyl, Protostat), or a combination of the two is effective.

Detección de portadores de Vibrio cholerae convalecientes mediante el enterotest / Detection of convalescent carriers of Vibrio cholerae using enterotest

Aunque se ha postulado la posible existencia de portadores crónicos de Vibrio cholerae, la información al respecto es escasa y contradictoria. Con objeto de determinar la utilidad de la cuerda encapsulada (enterotest) para detectar V. cholerae en las secreciones duodenales de origen biliar (biliduodenales), se evaluó a 59 pacientes (30 hombres y 29 mujeres) mayores de 15 años con diagnóstico clínico y bacteriológico de cólera. Todos los pacientes, que fueron atendidos en el Hospital de apoyo Departamental María Auxiliadora en Lima, Perú, fueron sometidos al mismo esquema de rehidratación y recibieron 2 g diarios de tetraciclina por 3 días. De 1 a 7 días después de determinado el tratamiento con antibióticos se realizaron las primeras pruebas de control: cultivo de secreciones biliduodenales mediante enterotest y coprocultivo mediante hisopado rectal. Ningún paciente tenía diarrea en el primer control. El cultivo de secreciones biliduodenales dio resultados positivos a V. cholerae en cinco pacientes (8,5 por ciento) (cuatro mujeres y un hombre) y el coprocultivo dio resultados negativos en todos loa casos. Una semana después se repitieron las pruebas de control de los cinco pacientes. Todos los cultivos de secreciones bilidiodenales fueron negativos y solamente un coprocultivo fue positivo en esta etapa. La paciente en cuestión fue sometida a las mismas pruebas de control una semana más tarde y ambas fueron negativas. Concluimos que el enterotest puede ser un método simple, bien tolerado y de bajo costo para detectar portadores de V. cholerae (AU)

Quantitation of salivary, urinary and faecal sIgA in children living in different conditions of antigenic exposure.

A sandwich-type ELISA was developed to quantify salivary, urinary and faecal secretory IgA (sIgA). The assay is based on binding of sIgA to microplates coated with anti-SC antibodies and reaction with peroxidase-labelled anti-IgA. The sensitivity of the technique was approximately 5 micrograms/L. Children, 1-6 years old (n = 142), were divided into two groups. Group 1 (n = 80) was composed of children living in a place with presumably low antigenic exposure conditions. Group 2 (n = 62) was composed of well-nourished (2A, n = 53) and malnourished children (2B, n = 9) living in a São Paulo slum with presumably high antigenic exposure. The subgroup 2A had salivary levels higher than group 1 and the ranges were similar to those found in the literature for older children and adults. The same subgroup presented a high incidence of undetectable faecal sIgA; their levels of urinary sIgA did not differ from group 1. The subgroup 2B did not have levels of salivary, urinary and faecal sIgA different from subgroup 2A. Our results suggest that environmental factors influence the ontogenesis of sIgA system.

Human giardiasis: correlation of specific secretory IgA levels in duodenal fluid to the severity of disease and infestation by Giardia lamblia.

Giardia lamblia specific secretory immunoglobulin A (sIgA) levels in the duodenal fluid of adult giardiasis cases are reported for the first time. The sIgA levels in the study group were found to be significantly higher (p less than 0.01) than in the 20 age- and sex-matched controls comprising cases classified as non-ulcerative dyspepsia who did nor reveal any G. lamblia in their stools and the duodenal fluid. An inverse relationship between the clinical severity of giardiasis and the level of sIgA in the duodenal fluid was noted. Cases with a higher trophozoite load in duodenal aspirate tended to be associated with envanescent G. lamblia-specific antibodies.

Giardia lamblia in patients undergoing upper G.I. endoscopy.

To determine the frequency of giardiasis in patients undergoing upper G.I. endoscopy for dyspepsia and other upper G.I. disorders, duodenal aspirates were collected in 200 patients and simultaneous duodenal biopsies in 163 patients. Nine percent aspirates and 1.8% duodenal biopsies showed Giardia lamblia trophozoites. Giardia as a cause of dyspepsia should be considered in patients with negative endoscopy and in those who remain symptomatic inspite of adequate treatment for known upper G.I. disorders.

Diagnosis of Strongyloides and hookworm infections: comparison of faecal and duodenal fluid microscopy.

Faecal microscopical diagnosis of Strongyloides and hookworm infections is insensitive. We have therefore compared duodenal fluid and faecal microscopy for detection of these parasites in a group of 292 patients being investigated for gastrointestinal symptoms who were examined by both techniques. Thirty-three of these patients (8%) were infected with Strongyloides stercoralis and 88 (30%) had hookworm infections. Microscopical examination of up to 3 faecal specimens detected only 33% and 65% of patients with Strongyloides and hookworm infections, respectively. Microscopical examination of a single specimen of duodenal fluid was more sensitive for detection of strongyloidiasis, identifying 76% of patients; the parasite was found exclusively in duodenal fluid (and not in faeces) in 67% of patients. For hookworm, the diagnostic sensitivity was similar with both techniques but duodenal fluid microscopy detected some patients (35%) who had not been identified by faecal microscopy. This study confirms previous work indicating the insensitivity of faecal microscopy in these infections and emphasizes the need to consider routine examination of duodenal fluid to exclude chronic strongyloidiasis. This may have particular relevance for south-east Asian war veterans and immunocompromised patients.

[Study of Strongyloides stercoralis in the duodenal juice obtained by the examination of a string capsule or the Enterotest]. / Investigación de Strongyloides stercoralis en jugo duodenal obtenido mediante el exámen de la "cuerda encapsulada" o Enterotest.

We present our experience in the investigation of Strongyloides stercoralis in the duodenal juice obtained by the "string capsule" o Enterotest, in 1,511 patients from the Gastroenterology Service of the National Hospital "Edgardo Rebagliati Martins" IPSS, between January 1985 to July 1990. We found 36 patients parasitized with Strongyloides stercoralis, an incidence of 2.4%. This method was good tolerated and have proved to be simple, fast, effective and allowing to examine simultaneously many patients at a very low cost.

Intestinal mucus protects Giardia lamblia from killing by human milk.

We have previously shown that nonimmune human milk kills Giardia lamblia trophozoites in vitro. Killing requires a bile salt and the activity of the milk bile salt-stimulated lipase. We now show that human small-intestinal mucus protects trophozoites from killing by milk. Parasite survival increased with mucus concentration, but protection was overcome during longer incubation times or with greater milk concentrations. Trophozoites preincubated with mucus and then washed were not protected. Protective activity was associated with non-mucin CsCl density gradient fractions. Moreover, it was heat-stable, non-dialyzable, and non-lipid. Whereas whole mucus inhibited milk lipolytic activity, protective mucus fractions did not inhibit the enzyme. Furthermore, mucus partially protected G. lamblia trophozoites against the toxicity of oleic acid, a fatty acid which is released from milk triglycerides by lipase. These studies show that mucus protects G. lamblia both by inhibiting lipase activity and by decreasing the toxicity of products of lipolysis. The ability of mucus to protect G. lamblia from toxic lipolytic products may help to promote intestinal colonization by this parasite.