FGF9-induced proliferative response to eosinophilic inflammation in oesophagitis

BACKGROUND

Oesophagitis is characterised by basal cell hyperplasia and activated eosinophils, which release mediators including major basic protein (MBP). MBP and its mimetic polyarginine activate the calcium sensing receptor (CaSR) on oesophageal epithelium. Fibroblast growth factor 9 (FGF9) is implicated in epithelial homeostasis and proliferative response to injury, but has not been characterised in the oesophagus.

OBJECTIVE

To characterise FGF9 in oesophageal epithelium and oesophagitis, as the result of MBP activation of the CaSR.

METHODS

Human oesophageal epithelial cells (HET-1A) were used to compare affects of calcium, polyarginine and MBP-peptide on FGF9. HET-1A were transfected with interfering RNA (siRNA(CaSR)). FGF9, FGF receptors 2 and 3, bone morphogenetic protein (BMP)-2, BMP-4 and noggin mRNA expression were detected by reverse transcriptase polymerase chain reaction. FGF9 was measured from HET-1A and from normal, gastro-oesophageal reflux and eosinophilic oesophagitis (EoE) patient biopsies using ELISA and immunohistochemistry. HET-1A proliferation was studied using bromodeoxyuridine and MTT.

RESULTS

FGF9 was secreted by HET-1A cells treated with polyarginine and MBP-peptide, but not calcium. This effect was abrogated by siRNA(CaSR). FGF9 receptor mRNA was present. HET-1A cells proliferated following rhFGF9, but not MBP-peptide treatment, and rhFGF9 altered transcription of downstream proliferation-related genes (noggin, BMP-2 and BMP-4). FGF9 was increased in biopsies from patients with eosinophilic oesophagitis, which correlated with basal hyperplasia.

CONCLUSION

Eosinophil-released MBP acts on the CaSR to increase FGF9 in oesophageal epithelial cells, leading to proliferation. Increased FGF9 is found in biopsies of EoE patients and may play a role in the pathogenesis of oesophagitis.

Corticosteroid pretreatment prevents small intestinal mucosal lesion induced by acetic acid-perfusion model in rats

One of the important problems in experimentally induced small intestinal lesions is that there is no reproducible model of diffuse and stable mucosal lesion. In this paper, we studied in detail the effects of continuous perfusion of various concentrations of acetic acid on the rat small intestinal mucosa. In order to evaluate its applicability for screening of the preventive effect of drugs on gut damage, we also evaluated the efficacy of corticosteroid pretreatment in preventing acetic acid-induced mucosal lesion. Male Sprague-Dawley rats were fasted for 12 hr, and the small intestinal lumen was perfused with 1%, 1.5%, 2.5%, 3%, 3.75% (pH 2.4-2.6) acetic acid or saline (control) at 1 ml/min for 15 min. In separate experiments, the effect of preadministration of budesonide (0.5 or 0.75 mg/kg/day) and prednisone (0.75 mg/kg/day) on 1.5% acetic acid-induced mucosal damage was investigated. Macroscopic and microscopic lesions occurred diffusely in a concentration-dependent fashion. Histological findings revealed signs of transmural inflammation characterized by mucosal-submucosal edema, ulceration, and neutrophil infiltration. Mucosal-submucosal height had an inverse relation with the acetic acid concentrations perfused. Myeloperoxidase activity levels increased several-fold in the acetic acid-perfused groups. Corticosteroid pretreatment prevented microscopic damage and was associated with reduction of MPO activity levels in 1.5% acetic acid-perfused rats. We conclude that this simple and reproducible model could be applied for the screening of new drugs in the gastrointestinal tract in which large numbers of animals are taken into account.

Effects of cyclosporin A on water-immersion stress-induced gastric lesion and gastric secretion in rats

Cyclosporin A is an immunosuppressive agent which is well known as a specific inhibitor of calcineurin (protein phosphatase 2B). In this study, we investigated the effects of cyclosporin A on water-immersion stress-induced gastric ulcer formation and gastric acid secretion in rats. We also examined the localization of calcineurin immunohistochemically. Calcineurin was specifically expressed in gastric parietal cells and chief cells of the gastric mucosa. The intraperitoneal administration of cyclosporin A dose-dependently suppressed the development of gastric mucosal lesions induced by water-immersion stress and inhibited gastric acid secretion, as assessed by pylorus ligation. These results indicated that calcineurin may play an important role in gastric acid secretion.

Purification and characterization of an iron superoxide dismutase and a catalase from the sulfate-reducing bacterium Desulfovibrio gigas

The iron-containing superoxide dismutase (FeSOD; EC 1.15.1.1) and catalase (EC 1.11.1.6) enzymes constitutively expressed by the strictly anaerobic bacterium Desulfovibrio gigas were purified and characterized. The FeSOD, isolated as a homodimer of 22-kDa subunits, has a specific activity of 1,900 U/mg and exhibits an electron paramagnetic resonance (EPR) spectrum characteristic of high-spin ferric iron in a rhombically distorted ligand field. Like other FeSODs from different organisms, D. gigas FeSOD is sensitive to H(2)O(2) and azide but not to cyanide. The N-terminal amino acid sequence shows a high degree of homology with other SODs from different sources. On the other hand, D. gigas catalase has an estimated molecular mass of 186 +/- 8 kDa, consisting of three subunits of 61 kDa, and shows no peroxidase activity. This enzyme is very sensitive to H(2)O(2) and cyanide and only slightly sensitive to sulfide. The native enzyme contains one heme per molecule and exhibits a characteristic high-spin ferric-heme EPR spectrum (g(y,x) = 6.4, 5.4); it has a specific activity of 4,200 U/mg, which is unusually low for this class of enzyme. The importance of these two enzymes in the context of oxygen utilization by this anaerobic organism is discussed.

[Ultrastructural identification of Ehrlichia sp in an experimentally infected dog in Venezuela]

This study is the first report made in Venezuela concerning the ultrastructural characteristics of Ehrlichia sp in mononuclear blood cells from an experimentally infected dog. The animal developed clinical manifestations characteristic of the infection, and typical intracitoplasmic inclusion bodies were clearly seen in blood smears stained with modified Giemsa examined by light microscopy. Microorganisms were visualized by transmission electron microscopy. The cytoplasmic inclusions, consisted of membrane-lined vacuole-containing elementary bodies. The organisms were extremely pleomorphic. Elementary bodies were surrounded by two distinct membranes and each was constituted by electro-dense granules. These findings corresponded to the described electron microscopy morphology which characterizes the Ehrlichia genus.

Crystallization and preliminary diffraction data analysis of both single and pseudo-merohedrally twinned crystals of rubredoxin oxygen oxidoreductase from Desulfovibrio gigas

Crystals of rubredoxin oxygen oxidoreductase have been obtained and characterized. They belong to space group P2(1)2(1)2, with unit-cell dimensions a = 88.24 (15), b = 101.25 (7), c = 90.80 (3) A. The homodimer (86 kDa) in the asymmetric unit is related by a non-crystallographic twofold rotation axis parallel to the ab 'diagonal' direction, as shown by the self-rotation maximum in the section with chi = 180 degrees. This pseudo-crystallographic symmetry element was also found to be the twinning axis of pseudo-merohedrally twinned crystals, leading to apparent pseudo-tetragonal P42(1)2 crystal symmetry.

Association of 72-kDa heat shock protein expression with adaptation to aspirin in rat gastric mucosa

It is well documented that gastric mucosa can increase its resistance to mucosal damage caused by aspirin during repeated long-term administration of aspirin. However, the underlying mechanism of this adaptation is not well established. In the present study, we investigated the effect of long-term (chronic) administration of aspirin on expression of heat shock proteins (HSPs), which are known as endogenous cytoprotectants, in rat gastric mucosa. Rats were administered aspirin (100 mg/kg) daily for up to 20 days. After various periods of aspirin administration, a high dose of aspirin (250 mg/kg) was administered, and the mucosal damage was assessed. Expression of heat shock proteins (HSPs) in gastric mucosa was evaluated by Western blot. Intracellular localization of each HSP was studied immunohistochemically. Prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels were also investigated. Long-term aspirin administration resulted in development of resistance to aspirin-induced mucosal damage, and the increase of HSP72 expression correlated with mucosal resistance to aspirin. No significant increase was observed in HSP60 and HSP90 levels. Immunohistochemical study showed an increase of HSP72 in the cytoplasm of mucosal surface cells. The PGE2 level was suppressed and no change in the level of LTB4 was observed. It is possible that HSP72 could play important roles in gastric mucosal adaptation when the PGE2 level is suppressed by NSAIDs.

The superoxide dismutase activity of desulfoferrodoxin from Desulfovibrio desulfuricans ATCC 27774

Desulfoferrodoxin (Dfx), a small iron protein containing two mononuclear iron centres (designated centre I and II), was shown to complement superoxide dismutase (SOD) deficient mutants of Escherichia coli [Pianzzola, M.J., Soubes M. & Touati, D. (1996) J. Bacteriol. 178, 6736-6742]. Furthermore, neelaredoxin, a protein from Desulfovibrio gigas containing an iron site similar to centre II of Dfx, was recently shown to have a significant SOD activity [Silva, G., Oliveira, S., Gomes, C.M., Pacheco, I., Liu, M.Y., Xavier, A.V., Teixeira, M., Le Gall, J. & Rodrigues-Pousada, C. (1999) Eur. J. Biochem. 259, 235-243]. Thus, the SOD activity of Dfx isolated from the sulphate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774 was studied. The protein exhibits a SOD activity of 70 U x mg-1, which increases approximately 2.5-fold upon incubation with cyanide. Cyanide binds specifically to Dfx centre II, yielding a low-spin iron species with g-values at 2.27 (g perpendicular) and 1.96 (g parallel). Upon reaction of fully oxidized Dfx with the superoxide generating system xanthine/xanthine oxidase, Dfx centres I and II become partially reduced, suggesting that Dfx operates by a redox cycling mechanism, similar to those proposed for other SODs. Evidence for another SOD in D. desulfuricans is also presented - this enzyme is inhibited by cyanide, and N-terminal sequence data strongly indicates that it is an analogue to Cu,Zn-SODs isolated from other sources. This is the first indication that a Cu-containing protein may be present in a sulphate-reducing bacterium.

Desulfovibrio gigas neelaredoxin. A novel superoxide dismutase integrated in a putative oxygen sensory operon of an anaerobe

Neelaredoxin, a small non-heme blue iron protein from the sulfate-reducing bacterium Desulfovibrio gigas [Chen, L., Sharma, P., LeGall, J., Mariano, A.M., Teixeira M. and Xavier, A.V. (1994) Eur. J. Biochem. 226, 613-618] is shown to be encoded by a polycistronic unit which contains two additional open reading frames (ORF-1 and ORF-2) coding for chemotaxis-like proteins. ORF-1 has domains highly homologous with those structurally and functionally important in methyl-accepting chemotaxis proteins, including two putative transmembrane helices, potential methylation sites and the interaction domain with CheW proteins. Interestingly, ORF-2 encodes a protein having homologies with CheW proteins. Neelaredoxin is also shown to have significant superoxide dismutase activity (1200 U. mg-1), making it a novel type of iron superoxide dismutase. Analysis of genomic data shows that neelaredoxin-like putative polypeptides are present in strict anaerobic archaea, suggesting that this is a primordial superoxide dismutase. The three proteins encoded in this operon may be involved in the oxygen-sensing mechanisms of this anaerobic bacterium, indicating a possible transcriptional mechanism to sense and respond to potential stress agents.

Functional and mechanistic studies of cytochrome c3 from Desulfovibrio gigas: thermodynamics of a "proton thruster"

Nuclear magnetic resonance and visible spectroscopies were used to determine the thermodynamic parameters of the four hemes in cytochrome c3 from Desulfovibrio gigas at 298 and 277 K and to investigate the mechanism of electron/proton energy transduction. Data obtained in the pH range from 5 to 9 were analyzed according to a model in which the hemes interact with each other (redox cooperativities) and with an ionizable center (redox-Bohr cooperativities). The results obtained at the two temperatures allow the deconvolution of the entropic contribution to the free energy of the four hemes, to the acid-base equilibrium of the ionizable center, and to the network of cooperativities among the five centers. The redox potentials of the hemes are modulated by the enthalpic contribution to the free energy, and evidence for the participation of the propionates of heme I in the redox-Bohr effect is presented. The network of interactions between the centers in this protein facilitates the concerted transfer of electrons and protons, in agreement with the "proton thruster" mechanism proposed for electronic to protonic energy transduction by cytochromes c3.

Radiographic predictors of outcome of core decompression for hips with osteonecrosis stage III

Various investigators have studied the prognostic influence of various demographic, laboratory, and radiographic parameters on outcome for different treatment methods for osteonecrosis of the femoral head. A cross sectional study was done of 52 patients (68 hips) who had a core decompression for Ficat and Arlet Stage III osteonecrosis of the femoral head. The purpose of this study was to evaluate the prognostic significance of various radiographic factors for risk of disease progression after treatment with core decompression. Radiographic parameters included Steinberg stages (III or IV), Ohzono stage (central or lateral location), amount of head depression, extent of crescent sign arc, and extent of lesion by Kerboul combined necrotic angle measurements. Patient outcome assessment was at a followup mean of 12 years (range, 4-18 years) after core decompression. Overall, 20 of the 68 hips (29%) had satisfactory outcomes. Of the 44 hips with Steinberg Stage III disease, 18 (41%) underwent total hip arthroplasty. In comparison, in the Steinberg Stage IV hips, 22 of 24 hips (92%) underwent arthroplasty. Ohzono Stage B lesions had 50% survival (eight of 16 hips) compared with 23% survival (12 of 52 hips) for Ohzono Stage C. Hips with combined necrotic angles greater than 250 degrees had 16% survival (seven of 45) which can be compared with 57% survival (13 of 23) for hips with angles less than 250 degrees. The best multiple regression model for a satisfactory outcome was a Steinberg Stage III hip (no head depression), a central lesion (Ohzono Stage B), and a small lesion (< 250 degrees combined necrotic angle). With this combination, there were 89% satisfactory outcomes (8 of 9 hips). Conversely, the best generalized linear model for unsatisfactory outcomes (0 hips surviving of 14) was Steinberg Stage IV disease (head depression), lateral location (Ohzono Stage C lesion), and a large extent of the lesion (> 250 degrees combined necrotic angle).

Characterisation of a new rubredoxin isolated from Desulfovibrio desulfuricans 27774: definition of a new family of rubredoxins

A new rubredoxin from the sulphate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774, grown with nitrate as terminal electron acceptor, was isolated and characterised. The protein is an 8.5 kDa monomer containing one iron atom per molecule, with a reduction potential of 25 +/- 5 mV at pH 7.6. Like the recombinant Rdl protein from D. vulgaris, expressed in Escherichia coli [Lumpio, H.L., Shenvi, N.V., Garg, R.P., Summers, A.O. and Kurtz, D.M., J. Bacteriol. 179 (1997) 4607-4615], it contains an unusual spacing of four amino acids between the first two of the iron coordinating cysteinyl residues. This difference is reflected in the structure of the iron centre, as observed by visible and EPR spectroscopies. All together, these features make these proteins the first members of a new family of rubredoxins.

Multiheme cytochromes from the sulfur-reducing bacterium Desulfuromonas acetoxidans

Two new multiheme cytochromes were isolated from the anaerobic sulfur reducing bacterium Desulfuromonas acetoxidans. They have monomeric molecular masses of 50 and 65 kDa and contain six and eight hemes, respectively. Visible and EPR spectroscopies, in the as-isolated (oxidised) cytochromes, show the presence of only low-spin hemes in the 50-kDa cytochrome, and of high-spin and low-spin hemes in the 65-kDa cytochrome. The EPR spectra of the native 65-kDa cytochrome indicate multiple heme-heme interactions, including integer-spin systems as judged by parallel-mode EPR. The 50-kDa cytochrome has a complex redox pattern, as shown by EPR redox titrations, and contains one heme with unusual characteristics. Both cytochromes cover an extremely wide range of reduction potentials, which go from +100 mV to -375 mV for the 50-kDa cytochrome, and +185 mV to -235 mV for the 65-kDa cytochrome. The two cytochromes were tested for hydroxylamine oxidoreductase activity and polysulfide reductase activity, but neither displayed any activity. In contrast, it was found for the first time that the previously characterised cytochrome c551.5, from the same bacterium is very active in the reduction of polysulfide, which suggests that it acts as a terminal reductase in D. acetoxidans.

Structural and functional characterization of cytochrome c3 from D. desulfuricans ATCC 27774 by 1H-NMR

Cooperativity between redox and protonation centres is known to be crucial for the function of complex proteins, but it is often difficult to describe in terms of thermodynamic parameters. Cytochrome c3 is a good model for these studies since, while retaining the overall complexity of larger systems, it is suitable for detailed crystallographic and spectroscopic studies. Assignment of the haem substituent NMR resonances, together with NMR redox titrations of cytochrome c3 from D. desulfuricans ATCC 27774, was used to correlate relative redox potentials to specific haems in the structure: haem II approximately equal to haem I < haem IV < haem III. This order is different from that determined for the homologous proteins studied and in disagreement with that previously reported for this cytochrome (Morais, J., Palma, N., Frazäo, C., Caldeira, J., LeGall, J., Moura, I., Moura, J.J.G. and Carrondo, M.A. (1995) Biochemistry 34, 12830-12841).

A seven-iron ferredoxin from the thermoacidophilic archaeon Desulfurolobus ambivalens

A seven-iron ferredoxin was isolated from aerobically grown cells of the hyperthermoacidophilic archaeon Desulfurolobus ambivalens (DSM 3772). The protein is monomeric, with an apparent molecular mass of 15 kDa and contains 7 iron atoms/molecule. The N-terminal sequence shows a large similarity (70% identity) with that of the ferredoxin isolated from the archaeon Sulfolobus acidocaldarius. The EPR characteristics in both the native (oxidized) and dithionite-reduced states of this protein allowed an unequivocal identification of a [3Fe-4S]1+/0 center, with a reduction potential of -270 +/- 20 mV, at pH 7.5. The protein also contains a [4Fe-4S]2+/1+ center with a very low reduction potential (Eo = -540 mV, pH 7.0), which yields a rhombic EPR spectrum upon reduction with sodium dithionite at high pH. The reduction potentials of both centers are slightly pH dependent between pH 6 and 9. The [3Fe-4S] ferredoxin center is able to accept electrons from pyruvate oxidase and NADH oxidase isolated from D. ambivalens. This ferredoxin is present in large amounts (at least 130 mg/kg wet cells), which allowed the unequivocal observation of oxidized [3Fe-4S] clusters in intact D. ambivalens cells.

Insulin gene transcription is decreased rapidly by lowering glucose concentrations in rat islet cells

Glucose is the main physiological regulator of insulin biosynthesis and secretion. To exert an effect on biosynthesis, stimulatory concentrations of glucose act on insulin gene expression at both transcriptional and posttranscriptional levels. The relative importance of these two effects is controversial. Studies on the effect of decreasing glucose concentrations in vitro have been contradictory as to its rapidity and magnitude. We have investigated whether a decrease in glucose concentrations from a stimulatory (11 mM) to a nonstimulatory (2 mM) level regulates insulin gene expression in both isolated rat islets and INS-1 cells, an insulinoma-derived cell line that retains a number of the differentiation characteristics of native beta-cells. We show that, in the presence of a nonstimulatory concentration of glucose, insulin mRNA levels decrease rapidly in both rat islets and INS-1 cells. Low glucose decreases insulin gene expression at the transcriptional level, and this effect is mediated by DNA sequences present within 254 base pairs of the 5'-flank of the rat insulin I gene. We conclude that lowering glucose from 11 to 2 mM decreases insulin mRNA rapidly by a transcriptional effect.

Chronic iron intake and diarrhoeal disease in infants. A field study in a less-developed country

The effect of chronic iron intake on diarrhoeal disease was evaluated in children in a community of low socio-economic stratum in Santiago, Chile. Children were incorporated into each of two consecutive cohorts; each cohort was divided into two groups, one receiving iron-enriched milk (12 mg/l) (monthly average = 70 children) and the other a control milk (1 mg/l) (monthly average = 83 children), and each cohort was followed up for 6 months. The incidence of diarrhoea was higher among the iron-supplemented children (30.4 vs 25.5 episodes/100 children/month, P < 0.025). This was mainly due to results obtained in infants 3-8 months of age during the summer months. Supplemented infants had more bowel movements on day 1 (P < 0.03) and liquid or semi-liquid stools were passed for more than 15 days more frequently (P < 0.05). While no differences were detected in aetiology, Shigella-associated episodes were less common among iron-supplemented infants (P < 0.008). Asymptomatic shedding of enteropathogens significantly increased in infants 12-18 months of age receiving iron-supplemented milk. In areas with inadequate environmental sanitation, chronic iron supplementation may have negative effects on diarrhoeal morbidity, despite improving iron nutritional status.

Structure determination of a novel cyclic phosphocompound isolated from Desulfovibrio desulfuricans

The structure of a novel diphosphodiester compound recently detected in Desulfovibrio desulfuricans cells [Santos, Fareleira, Pedregal, LeGall & Xavier (1991) Eur. J. Biochem. 201, 283-287] was fully elucidated using a combination of n.m.r. techniques in aqueous and in methanolic solutions. The novel metabolite was identified as 3-methyl-1,2,3,4-tetrahydroxybutane-1,3-cyclic bisphosphate, and the minimum energy conformation is presented. The two chiral centres have the relative configuration RS.

[Application of a model for predicting morbidity in children from a low socioeconomic level]

An instrument to be used at a primary health care level was built on the basis of a predictive model for diarrhea obtained during a previous study. The instrument was applied to 720 mothers or caregivers of infants living in the Southeastern area of Santiago. 83 infants who fulfilled the requisites of the instrument were surveyed during July-August 1989 and compared to age, nutritional and socioeconomic status matched children not fulfilling the same requisites. Infants selected by the predictive instrument suffered 4 times more morbid episodes and respiratory infections and 5 times more diarrheal episodes than controls. Symptoms were present in them during 50% of the survey period as opposed to 14% in controls. Mothers of children at risk had inadequate behaviors in respect to health care of their children and did not follow many of the National Health programs available for their families. The predictive instrument tested may be useful to identify children at high risk of morbidity, creating the possibility for special interventions in them.

[Cryptosporidiosis: studies in children in communities of low socioeconomic level]

Cryptosporidium was detected in 2 (1.5%) out of 132 children under 2 years with acute diarrhea; in 2 (3.2%) out of 63 patients under 2 years with persistent diarrhea; in 1 (3.9%) out of 26 malnourished patients younger than 2 years with an episode of acute diarrhea and in 7 (1.4%) out of 516 pediatric ambulatory patients who consulted for acute or chronic diarrhea or recurrent abdominal pain. The clinical histories of the 5 infants with cryptosporidiosis who belonged to the first 3 studies, are presented. All they had prolonged diarrhea (more than 15 days long), and one of them showed low IgG and IgA serum concentrations, but normal proportions of T lymphocyte populations.

[Prevalence of herpetic infection in a female Chilean population]

The prevalence of the herpes simplex virus infection was investigated in a chilean female population. During 1981 and 1985 a number of 1,003 women were analyzed through serological methods. A 29.1% of the group referred past history of oral herpes and 59.4% of these presented 1 to 2 recurrent episodes a year. The high prevalence of this infection in our population is shown when detecting that a 91.4% of the female population had antiherpes simplex antibodies and the titer of this antibodies were in direct correlation to the antecent of recurrent clinical herpes and to the frequency of these episodes.

[Trial of milk with low-lactose contents in acute diarrhea]

Fifty infants with acute diarrhea (less than or equal to 5 days of duration) were refed with either a low-lactose formula (experimental group, N = 25) or whole powdered cow's milk (control group, N = 25). During a two-month follow up etiology, clinical course, changes of anthropometric parameters and tolerance to the milk products were evaluated. The etiology of diarrhoea, the mean duration of the episodes (3.6 +/- 1.9 and 3.9 +/- 1.9 days in the experimental and control group, respectively) and the clinical course were comparable in both groups. Nutritional parameters remained unchanged during and after the episode. In two children (8.3%) of the control group stools continued to be liquid, fecal pH was 5 and reducing substances were positive. They had to be refed with the low-lactose product to induce remission of the symptoms. Both products were well tolerated. These findings suggest that availability of low-lactose formulae may be advantageous in the clinical management of infants with acute diarrhea and evidence of lactose intolerance.

Effect of an acidified milk on diarrhoea and the carrier state in infants of low socio-economic stratum

The effect on diarrhoeal disease of an acidified, modified powdered cow's milk infant formula (Pelargon) was evaluated in 82 infants (Group I) for six months; 104 infants who received the same formula but non acidified, served as controls (Group II). Nutritional status remained satisfactory in both groups throughout the observation period. Some children rejected the taste of the acidified milk. The incidence of diarrhoea was lower in Group I (p less than 0.001). The proportion of days in which the children suffered from acute diarrhoea, and the duration of the episodes were also lower in the children given the acidified milk (p less than 0.001). The rate of detection of enteropathogens and the species identified were comparable in both groups. Carrier rates for bacterial enteropathogens fell over time in Group I while they rose in Group II (p less than 0.001). Carrier rates for enteric parasites were comparable to those expected in our setting for this age group. These results suggest that acidified milk exerts a protective effect against diarrhoeal disease.

[Retrospective evaluation of persistent diarrhea at a primary health service]

Information about persistent diarrhea is scarse despite the fact that it is a frequent cause of death in children who live in developing countries. The 36,358 pediatric consultations performed at a Primary Health Care Center in Southeastern Santiago in 1984 were retrospectively evaluated. Diarrheic syndromes represented 5.1% of consultations and corresponded to 909 episodes; of these, 6.3% were cases of persistent diarrhea (greater than 15 days). The highest frequency occurred among children under 2 years of age (60.7%). In 68.7% of cases feces were liquid and in 37.5% mucus, pus or blood was present in stools. Persistent diarrhea was more frequent among malnourished patients (p less than 0.001) who, in turn, suffered the greatest nutritional deterioration in relation to the episode of diarrhea. Intravenous fluids were required by 23.3% of patients while 27.9% were admitted to hospital. This contrasts with patients who suffer episodes which lasted less than 15 days, who were all orally hydrated and only 7.8% required hospitalization (p less than 0.01).

Faecal excretion of rotavirus and other enteropathogens in newborns of the high and low socio-economic stratum in Santiago, Chile

Faecal excretion of enteropathogens was studied in newborns in their first week of life. Rotavirus was investigated in 225 neonates, of whom 107 belonged to the low socio-economic stratum (SES) and 118 to the high SES. Half of each group were delivered by caesarean section. Rotavirus was detected in 10 infants (4.4%). Eight of them had been in the same ward and excreted the same viral electrophoretype. Enteropathogenic bacteria were isolated from 8 out of 57 (14.0%) newborns. Positive cultures were equally distributed by SES and route of delivery. Giardia lamblia was the only parasite detected, in one infant (2.6%) of the high SES. None of the children developed symptoms. Faecal excretion of enteropathogens ended spontaneously within a week in all cases. It is suggested that the lack of symptomatology and the spontaneous termination of the faecal excretion are related to immaturity of the small intestinal mucosa, that does not allow the completion of the steps that must take place during a successful infectious event.

Prophylactic indomethacin for prevention of intraventricular hemorrhage in premature infants

The impact of early prophylactic use of intravenous indomethacin on the incidence and severity of periventricular-intraventricular hemorrhage and patent ductus arteriosus in 199 oxygen-requiring premature infants (less than or equal to 1300 g birth weight) was prospectively investigated. The trial was controlled, the infants were randomized, and the investigators were unaware of the group assignments. Patients with minimal (grade I) or no periventricular-intraventricular hemorrhage determined by prestudy echoencephalography were randomized within two birth weight subgroups (500 to 899 and 900 to 1300 g) to receive either prophylactic indomethacin (n = 99) or an equal volume of saline-vehicle placebo (n = 100). The first dose (0.2 mg/kg) was given within 12 hours of delivery and two subsequent doses (0.1 mg/kg) were administered at 12 hourly intervals. Prophylactic indomethacin significantly reduced the incidence of grades II to IV periventricular-intraventricular hemorrhage. Intraventricular hemorrhage was half as common in infants given prophylactic indomethacin as in control infants (23% v 46%, P less than .002). The reduction was manifested in both birth weight subgroups. Results of this study also confirmed a lower incidence of clinically significant patent ductus arteriosus in infants who received prophylactic indomethacin in contrast to those who received placebo (11% v 42%, P less than .001). No significant differences were found between treatment and control groups in the duration of oxygen therapy, mechanical ventilation, or hospitalization or in the incidence of pneumothorax, chronic lung disease, sepsis, necrotizing enterocolitis, retinopathy of prematurity, or death. Early prophylactic indomethacin initiated within 12 hours of delivery is effective in reducing the incidence of intraventricular hemorrhage as well as clinically significant patent ductus arteriosus in very low birth weight premature infants.

Effect of structured dietary fiber on bioavailability of amoxicillin

The effect of structured dietary fiber on the bioavailability of amoxicillin (AMX) was evaluated. Ten healthy volunteers ingested one of two isocaloric, isonitrogenous diets providing 7.8 gm/day (diet I) and 36.2 gm/day (diet II) of structured fiber for 3 days. Then they ingested one tablet (500 mg) AMX after breakfast. The other diet was administered for an additional 3 days and the study was repeated. Plasma and urinary AMX concentrations were measured at 9 and 24 hours, respectively, by a microbiologic technique. An open one-compartment model was used for pharmacokinetic analysis. AMX was absorbed more slowly when ingested with diet I than with diet II: the absorption rate constant was 1.04 +/- 0.37 and 1.75 +/- 0.75 (P less than 0.05); lag time for absorption was 0.34 +/- 0.13 hours and 0.29 +/- 0.11 hours (P less than 0.05). The first-order rate constant and elimination half-life were similar. Bioavailability was higher with diet I: the AUC was 12.17 +/- 3.04 vs. 9.65 +/- 2.64 micrograms/ml/hr with diet II (P less than 0.05). A higher content of dietary fiber increased AMX absorption rate and decreased the amount of drug absorbed.

Chronic environmental enteropathy in a temperate climate

Forty-three apparently healthy young adult male volunteers underwent an evaluation of their nutritional status, blood chemistry and faecal excretion of enteropathogens, which did not reveal current malnutrition or illnesses. Ten of them were further studied for small intestinal histology, culture of aerobic and anaerobic bacteria in the duodenal juice, disaccharidase activities, glucose absorption and faecal excretion of fat and nitrogen. The study revealed mild morphological changes associated with the appearance of anaerobic bacteria in the upper intestine, decreased glucose transport and increased faecal losses of nitrogen. Although all these changes were rather mild, they may be significant for people whose diet is of borderline nutritional quality.