Simulated human digestion of N1-aryl-2-arylthioacetamidobenzimidazoles and their activity against Herpes-simplex virus 1 in vitro.

Drug performance in the gastrointestinal tract (GIT) plays a crucial role in determining release and absorption. In the present work, we assessed the in vitro digestion of two synthetic N1-aryl-2-arylthioacetamidobenzimidazoles (NAABs), NAAB-496 and NAAB-503, using bio-relevant models of the human stomach and small intestine. The activity of NAAB-496 and NAAB-503 against herpes simplex virus (HSV-1) replication was also investigated. NAAB-496 was resistant to pepsin in the gastric environment, with a virtual 100% recovery, which decreased to 43.2% in the small intestine. NAAB-503 was sensitive to pepsin, with 65.7% degradation after 120 min gastric phase. 1H Nuclear magnetic resonance (NMR) post in vitro digestion highlighted an alteration of NAAB-496 after the gastric phase, whereas NAAB-503 appeared comparable to the original spectral data. Both NAAB-496 and NAAB-503 revealed some antiviral activity anti-HSV-1. The 50% effective concentration (EC50) of the compounds was 0.058 mg/mL for NAAB-496 and 0.066 for NAAB-503. Future studies will evaluate the behavior of NAAB-496 within pharmaceutical formulations.

Phage survival: the biodegradability of M13 phage display library in vitro.

Administration of bacteriophages is used for phage therapy modulation of gut microbiome or for in vivo phage display. The aim of the study was to analyze the survival of M13 phage in different body fluids and tissues in vitro. The survival of M13 phage was measured in vitro in human blood, saliva, urine, artificial gastric juice (AGJ), and mouse homogenates of stomach, jejunum, and colon after defined time points (5, 15, or 45 Min). The plates were inspected after overnight incubation and the plaques were counted. No phage was recovered after 5 Min of incubation with AGJ. In urine, the phage survival was decreased by 44% after 5 Min of incubation (P = 0.004). In saliva, the recovered titer was decreased by 33% and 88% (P < 0.05) after 15 and 45 Min, respectively. Phage coincubation with jejunum homogenate led to significant decrease of phage titer by 72% (P < 0.01) after 15 Min and by 99% (P < 0.001) after 45 Min. Decreased survival of M13 phage depending on time of incubation was proved under several in vitro conditions, with low pH in the AGJ having the most detrimental effect on phage survival. Phage pharmacokinetics described in vitro might have applications for the use of bacteriophages in vivo.

[Relationship of gastric microflora and neopterin content in gastric juice in children with chronic gastroduodenitis].

The study included 71 children with chronic gastroduodenitis aged 5-17 years. PCR DNA was determined by the presence of Helicobacter pylori, human papilloma virus high cancer risk 16, 18 types (HPV), herpes simplex 1 and type 2 (HSV), cytomegalovirus (CMV), fungi, Candida in gastric juice and biopsy specimens of gastric mucosa and duodenal. Viruses were detected in 14% of patients, an association of microorganisms - in 20% of the children, the isolated H. pylori infection - 18%. The relationship between the composition of microflora in the gastroduodenal region and neopterin levels in gastric juice with a distinct increase in its value in the presence of viruses.

Systemic trafficking of plant virus nanoparticles in mice via the oral route.

The plant virus, cowpea mosaic virus (CPMV), is increasingly being used as a nanoparticle platform for multivalent display of peptides. A growing variety of applications have employed the CPMV display technology including vaccines, antiviral therapeutics, nanoblock chemistry, and materials science. CPMV chimeras can be inexpensively produced from experimentally infected cowpea plants and are completely stable at 37 degrees C and low pH, suggesting that they could be used as edible or mucosally-delivered vaccines or therapeutics. However, the fate of CPMV particles in vivo, or following delivery via the oral route, is unknown. To address this question, we examined CPMV in vitro and in vivo. CPMV was shown to be stable under simulated gastric conditions in vitro. The pattern of localization of CPMV particles to mouse tissues following oral or intravenous dosing was then determined. For several days following oral or intravenous inoculation, CPMV was found in a wide variety of tissues throughout the body, including the spleen, kidney, liver, lung, stomach, small intestine, lymph nodes, brain, and bone marrow. CPMV particles were detected after cardiac perfusion, suggesting that the particles entered the tissues. This pattern was confirmed using methods to specifically detect the viral capsid proteins and the internal viral RNA. The stability of CPMV virions in the gastrointestinal tract followed by their systemic dissemination supports their use as orally bioavailable nanoparticles.

[Hepatitis C virus contamination of endoscopes and biopsy forceps]. / Contamination des endoscopes et des pinces à biopsies par le virus de l'hépatite C.

BACKGROUND: Procedures such as digestive endoscopy may explain some unclear contaminations by HCV. AIMS: The aims of this study were to detect HCV genome on endoscopes and biopsy-forceps used in patients with known chronic HCV infection and to determine its presence in their gastric juice and saliva. METHODS: A gastroscopy with antral biopsies was performed in 48 patients with non-treated replicative chronic hepatitis C. Samples were obtained after pushing 10 mL of sterile water through the biopsy-suction channel and after immersing the brush used to clean this channel. The biopsy-forceps were also immersed and their tips brushed in 10 mL of sterile water. This sampling technique was repeated three times: immediately after the endoscopic procedure (T0), after washing with a detergent (T1) and after immersion for 20 minutes in a 2% glutaraldehyde solution (T2). The HCV genome was detected by polymerase chain reaction (PCR, Amplicor - Roche Diagnostics Systems). For the last 15 patients, samples of gastric juice and saliva were obtained before antral biopsies and used to detect HCV genome. RESULTS: HCV genome was detected in the biopsy-suction channel in 13 cases (27%) at T0 and in one case (2%) at T1. It was undetectable after completion of the disinfection procedure (T2). Three biopsy-forceps (6%) were PCR positive immediately after the endoscopy but none at T1 and T2. HCV genome was found in the gastric juice in three cases. In all of them, it was also found at T0 in the biopsy-suction channel but not on the biopsy-forceps. When saliva contained HCV genome (4 cases), it was present in the biopsy-suction channel in only one case. In this case, the gastric juice was also PCR positive. CONCLUSIONS: HCV genome is detected in 27% of cases in the biopsy-suction channel after an endoscopic procedure performed on patients with chronic HCV infection. The biopsy-forceps are PCR positive in 6% of cases. The infected gastric juice may play a role in the contamination of the endoscopes. The complete disinfection procedure seems effective to eliminate HCV.

Frequent detection of HIV-1 in the gastric aspirates of neonates born to HIV-infected mothers.

OBJECTIVE: To evaluate the frequency and correlates of oral route exposure of infants born to HIV-1-infected women. METHODS: A multicenter study was performed within the prospective French Perinatal Cohort Study of mother-to-child HIV transmission. Oropharyngeal and gastric aspirates from 122 neonates were studied by reverse transcriptase (RT) polymerase chain reaction (PCR) for the presence of HIV-1, as well as for standard microbiology (Gram staining and culture). RESULTS: Aspirates from 101 neonates were analyzed by RT-PCR; 28% of these were positive for HIV RNA. Another 21 aspirates could not be tested because of PCR inhibition. The median concentration of HIV RNA in the positive aspirates was 126 copies/ml (range: 8-1270). Detection of HIV-1 in the aspirate was significantly related to high maternal plasma-viral load, presence of blood in the aspirate, positive Gram stain or culture, episiotomy or perineal lesions, and sexually transmitted infections during the pregnancy. Most of the mothers received zidovudine prophylaxis during pregnancy and delivery. Among the six infants who were infected with HIV, three had positive aspirates. Of the three assumed to have acquired the infection intrapartum, only one had an HIV RNA-positive aspirate. CONCLUSION: Exposure of the fetus to HIV via the oral route occurs frequently, even in the presence of zidovudine prophylaxis, and is likely to be one of the mechanisms of intrapartum transmission, but not the only one.

Neonatal gastric aspirates as a predictor of perinatal hepatitis B virus infections.

OBJECTIVE: To elucidate possible routes and predictors of perinatal transmission of hepatitis B virus (HBV). METHOD: This was a prospective follow-up study. One hundred and forty-seven out of 1762 pregnant women who were screened in the antenatal clinic of a university teaching hospital were HBsAg carriers. Enzyme immunoassay was used for determination of hepatitis B markers. Occurrence of HBsAg in newborns' gastric aspirates, newborns' and infants' blood, and maternal milk samples were determined. Their relationship with delivery routes and duration of the first stage of labor were analyzed by chi square test. RESULTS: The presence of HBsAg in newborns' gastric aspirates was strongly associated with the acquisition of HBsAg by the babies. There was no correlation between the rate of infant antigenemia and the duration of the first stage of labor, nor did cesarean section decrease the rate of vertical transmission of HBV. CONCLUSIONS: This is the first report to provide direct evidence for the major role of the oral route in vertical transmission of HBV during delivery. In addition to maternal serum HBeAg, HBsAg status in newborn's gastric aspirates is another important determinant for vertical transmission of HBV.