Heparan sulphate, its derivatives and analogues share structural characteristics that can be exploited, particularly in inhibiting microbial attachment

Heparan sulphate (HS) and the related polysaccharide, heparin, exhibit conformational and charge arrangement properties, which provide a degree of redundancy allowing several seemingly distinct sequences to exhibit the same activity. This can also be mimicked by other sulphated polysaccharides, both in overall effect and in the details of interactions and structural consequences of interactions with proteins. Together, these provide a source of active compounds suitable for further development as potential drugs. These polysaccharides also possess considerable size, which bestows upon them an additional useful property: the capability of disrupting processes comprising many individual interactions, such as those characterising the attachment of microbial pathogens to host cells. The range of involvement of HS in microbial attachment is reviewed and examples, which include viral, bacterial and parasitic infections and which, in many cases, are now being investigated as potential targets for intervention, are identified.

Heparan sulphate, its derivatives and analogues share structural characteristics that can be exploited, particularly in inhibiting microbial attachment.

Heparan sulphate (HS) and the related polysaccharide, heparin, exhibit conformational and charge arrangement properties, which provide a degree of redundancy allowing several seemingly distinct sequences to exhibit the same activity. This can also be mimicked by other sulphated polysaccharides, both in overall effect and in the details of interactions and structural consequences of interactions with proteins. Together, these provide a source of active compounds suitable for further development as potential drugs. These polysaccharides also possess considerable size, which bestows upon them an additional useful property: the capability of disrupting processes comprising many individual interactions, such as those characterising the attachment of microbial pathogens to host cells. The range of involvement of HS in microbial attachment is reviewed and examples, which include viral, bacterial and parasitic infections and which, in many cases, are now being investigated as potential targets for intervention, are identified.

Burden of acute gastrointestinal illness in the Metropolitan region, Chile, 2008.

The purpose of this study was to determine the magnitude and distribution of acute gastrointestinal illness (GI) in the Chilean population, describe its burden and presentation, identify risk factors associated with GI and assess the differences between a 7-day, 15-day and a 30-day recall period in the population-based burden of illness study design. Face-to-face surveys were conducted on 6047 randomly selected residents in the Metropolitan region, Chile (average response rate 75·8%) in 2008. The age-adjusted monthly prevalence of GI was 9·2%. The 7-day recall period provided annual incidence rate estimates about 2·2 times those of the 30-day recall period. Age, occupation, healthcare system, sewer system, antibiotic use and cat ownership were all found to be significant predictors for being a case. This study expands on the discussion of recall bias in retrospective population studies and reports the first population-based burden and distribution of GI estimates in Chile.

Bilateral megaureters in the Adriamycin rat model.

Congenital obstructive uropathy is associated with significant morbidity and mortality in the human neonate. The pathophysiology of congenital obstructive uropathy is poorly understood. There are very few experimental models of prenatal obstruction of the urinary tract, except in the fetal lamb or inbred rats. Prenatal exposure to Adriamycin in a rat model leads to a spectrum of malformations including urinary tract anomalies. We hypothesized that Adriamycin administration during a particular time frame could yield a high incidence of urinary tract anomalies and therefore designed this study to investigate the rates of urinary tract anomalies at different windows of Adriamycin injection in rat embryos. Adriamycin (1.75 mg/kg) was administered intraperitoneally to pregnant rats at different times from days 6 to 10 of gestation. Control animals were given saline. Embryos recovered on gestational day 21 by cesarean section were examined for urinary tract anomalies, and malformations were noted. Sections were then processed for paraffin embedding, sectioned at 5 mum, and stained with hematoxylin and eosin for histological examination. Anomalies of the urinary tract occurred maximally following Adriamycin administration on days 7, 8, and 9 of gestation (91.6%) compared with 16% of controls. The most common urinary tract anomaly in the Adriamycin group was bilateral megaureters with a hypoplastic bladder (81%). Other anomalies included unilateral or bilateral ureterohydronephrosis with a normal-sized bladder, duplex kidney, and unilateral or bilateral renal agenesis. In conclusion, the critical embryologic window for the development of bilateral megaureters with a small bladder in the Adriamycin rat model occurs following Adriamycin administration on gestational days 7-9. This simple experimental model of bilateral megaureter may allow further research into the pathophysiology of this condition.

Histopathological differences between recto-sigmoid Hirschsprung's disease and total colonic aganglionosis.

Total colonic aganglionosis (TCA) is a severe form of ultra long Hirschsprung's disease with an incidence of 2 to 14% among all forms of intestinal aganglionosis. C-kit positive interstitial cells of Cajal (ICCs) are pacemaker cells that play a key role in the motility function of the bowel. The aim of this study was to compare the innervation and ICCs distribution in total colonic and recto-sigmoid HD. Full thickness colonic specimens were obtained from four children with TCA, ten with recto-sigmoid HD and four controls. Single immunohistochemistry using peripherin, neuronal nitric oxide synthase (nNOS) and c-kit antibody was performed and analysed in light microscopy. Additionally, whole-mount preparations were stained using anti c-kit immunohistochemistry and NADPH-diaphorase. In the ganglionic bowel of TCA, recto-sigmoid HD and control patients there was a strong nNOS and peripherin immunoreactivity (IR) in ganglia of myenteric and submucous plexus and in thin nerve fibres in the muscle layers. In the TCA there was weak or lack of nNOS IR in the sparse, short nerve trunks of the myenteric and submucous plexuses and muscle layers, whereas nNOS weakly positive nerve trunks were observed in the recto-sigmoid HD bowel. Peripherin IR was markedly reduced in the TCA specimens compared to recto-sigmoid HD. In the TCA specimens there was a lack of ICCs-MY in the smooth muscle layer in all the specimens, whereas in the recto-sigmoid aganglionic bowel ICCs-MY were markedly reduced. Whole-mount preparations showed lack of ICCs-MY and a markedly reduced number of NADPH-positive nerve trunks in TCA. Our findings demonstrate clear histopathological differences between rectosigmoid Hirschsprung's disease and total colonic aganglionosis.

Mutation analysis of the RET gene in total intestinal aganglionosis by wave DNA fragment analysis system.

BACKGROUND/PURPOSE: Total intestinal aganglionosis (TIA) extending from the duodenum to the rectum is the most rare form of Hirschprung's disease (HSCR) and usually is fatal. RET is the major gene associated with HSCR, and germline mutations of this gene account for up 50% of familial and up to 15 to 20% of sporadic cases in HSCR. The aim of this study was to investigate DNA variants in the RET gene in TIA patients using the WAVE DNA Fragment Analysis System. METHODS: Genomic DNA was extracted from whole blood samples from 6 patients with TIA. Polymerase chain reaction (PCR) amplification of the 21 exons of RET was performed using published oligonucleotide primers. Heteroduplexes were followed by the WAVE DNA Fragment Analysis System with the DNASep cartridge. RESULTS: WAVE system technology detected 16 variants in the RET gene in the 6 patients with TIA. Three patients had a significant mutation in exon 8, 11, and 15, respectively. Thirteen RET polymorphic variants also were detected in the 6 patients, with L746L variant in exon 13 occurring in 4 patients. CONCLUSIONS: WAVE system technology is an efficient method for the detection of DNA sequence variants. Our findings suggest that not only RET mutations but also RET polymorphic variants may contribute to the occurrence of TIA.

[The detection of chronic Salmonella typhi carriers: a practical method applied to food handlers]. / Detección de portadores crónicos de Salmonella typhi: método práctico aplicado a manipuladores de alimentos.

We evaluated the anti Vi test to detect S typhi carriers in 1006 food handlers of 65 locations in central Santiago (Chile): 710 males and 296 females, age range 17 to 67. Positive reactions were found in 27 subjects, titers varying from 1/40 in 9 to 1/160 in 1 subject. Culture of feces, along with urine and bile cultures in those with very high titers allowed isolation of S typhi in 2 subjects, one with a 1/40 titer, the other 1/160. None had clinical history of typhoid fever, both had received parenteral vaccination. These results compare favorably with the classic technique which would have required 3018 fecal cultures (vs 108 in the present study) and a total cost of US$ 1730 vs US$ 364. In addition, anti-Vi detection is readily accepted by the subjects. Therefore, we recommend this technique as a screening prior to culture techniques in the identification of chronic S typhi carriers.