Validation of an instrument for dentists' perception of pain in patients with communication difficulties

Pain is present in the dental clinic, whether due to oral problems such as dental caries and its complications or related to dental procedures. Pain evaluation in patients with communication difficulties (PCDs) is challenging for dentists, potentially compromising treatment. The aim of this study was to develop and validate an instrument to assess the perception of dentists about pain in PCDs. This study followed a quantitative methodological approach involving constructing and validating an instrument administered to 50 dentists. The initial instrument consisted of 29 items divided into four domains. Content and construct validity and internal consistency were confirmed. Content validation was performed by judges using the Content Validity Index. The instrument underwent construct validation and internal consistency assessments through exploratory factor analysis and confirmatory factor analysis using Cronbach's α, Kaiser-Meyer-Olkin, and Bartlett's sphericity tests. The final instrument consisted of 21 items divided into three domains, with a high Cronbach's α for one domain and moderate values for the others. The total variance accounted for was above 46.03%. Each factor retained at least three items, with factor loadings greater than 0.3, commonalities greater than 0.2, and eigenvalues >1. Despite the study's limitations, the instrument demonstrated its applicability and potential in evaluating the perception and management of pain in PCDs.

Alanyl-glutamine protects the intestinal barrier function in trained rats against the impact of acute exhaustive exercise

Strenuous exercise triggers deleterious effects on the intestinal epithelium, but their mechanisms are still uncertain. Here, we investigated whether a prolonged training and an additional exhaustive training protocol alter intestinal permeability and the putative effect of alanyl-glutamine (AG) pretreatment in this condition. Rats were allocated into 5 different groups: 1) sedentary; 2 and 3) trained (50 min per day, 5 days per week for 12 weeks) with or without 6 weeks oral (1.5 g/kg) AG supplementation; 4 and 5) trained and subjected to an additional exhaustive test protocol with or without oral AG supplementation. Venous blood samples were collected to determine gasometrical indices at the end of the 12-week protocol or after exhaustive test. Lactate and glucose levels were determined before, during, and after the exhaustive test. Ileum tissue collected after all experimental procedures was used for gene expression analysis of Zonula occludens 1 (ZO-1), occludin, claudin-2, and oligopeptide transporter 1 (PepT-1). Intestinal permeability was assessed by urinary lactulose/mannitol test collected after the 12-week protocol or the exhaustive test. The exhaustive test decreased pH and base excess and increased pCO2. Training sessions delayed exhaustion time and reduced the changes in blood glucose and lactate levels. Trained rats exhibited upregulation of PEPT-1, ZO-1, and occludin mRNA, which were partially protected by AG. Exhaustive exercise induced intestinal paracellular leakage associated with the upregulation of claudin-2, a phenomenon protected by AG treatment. Thus, AG partially prevented intestinal training adaptations but also blocked paracellular leakage during exhaustive exercise involving claudin-2 and occludin gene expression.

Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

Impact of acute undernutrition on growth, ileal morphology and nutrient transport in a murine model

Undernutrition represents a major public health challenge for middle- and low-income countries. This study aimed to evaluate whether a multideficient Northeast Brazil regional basic diet (RBD) induces acute morphological and functional changes in the ileum of mice. Swiss mice (∼25 g) were allocated into two groups: i) control mice were fed a standard diet and II) undernourished mice were fed the RBD. After 7 days, mice were killed and the ileum collected for evaluation of electrophysiological parameters (Ussing chambers), transcription (RT-qPCR) and protein expression (western blotting) of intestinal transporters and tight junctions. Body weight gain was significantly decreased in the undernourished group, which also showed decreased crypt depth but no alterations in villus height. Electrophysiology measurements showed a reduced basal short circuit current (Isc) in the undernourished group, with no differences in transepithelial resistance. Specific substrate-evoked Isc related to affinity and efficacy (glutamine and alanyl-glutamine) were not different between groups, except for the maximum Isc (efficacy) induced by glucose. Transcription of Sglt1 and Pept1 was significantly higher in the undernourished group, while SN-2 transcription was decreased. No changes were found in transcription of CAT-1 and CFTR, while claudin-2 and occludin transcriptions were significantly increased in the undernourished group. Despite mRNA changes, SGLT-1, PEPT-1, claudin-2 and occludin protein expression showed no difference between groups. These results demonstrate early effects of the RBD on mice, which include reduced body weight and crypt depth in the absence of significant alterations to villus morphology, intestinal transporters and tight junction expression.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/-) and wild-type (APOE+/+) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

From Escherichia coli heat-stable enterotoxin to mammalian endogenous guanylin hormones

The isolation of heat-stable enterotoxin (STa) from Escherichia coli and cholera toxin from Vibrio cholerae has increased our knowledge of specific mechanisms of action that could be used as pharmacological tools to understand the guanylyl cyclase-C and the adenylyl cyclase enzymatic systems. These discoveries have also been instrumental in increasing our understanding of the basic mechanisms that control the electrolyte and water balance in the gut, kidney, and urinary tracts under normal conditions and in disease. Herein, we review the evolution of genes of the guanylin family and STa genes from bacteria to fish and mammals. We also describe new developments and perspectives regarding these novel bacterial compounds and peptide hormones that act in electrolyte and water balance. The available data point toward new therapeutic perspectives for pathological features such as functional gastrointestinal disorders associated with constipation, colorectal cancer, cystic fibrosis, asthma, hypertension, gastrointestinal barrier function damage associated with enteropathy, enteric infection, malnutrition, satiety, food preferences, obesity, metabolic syndrome, and effects on behavior and brain disorders such as attention deficit, hyperactivity disorder, and schizophrenia.

Sildenafil decreases rat tracheal hyperresponsiveness to carbachol and changes canonical transient receptor potential gene expression after antigen challenge

Inhibition of type-5 phosphodiesterase by sildenafil decreases capacitative Ca2+ entry mediated by transient receptor potential proteins (TRPs) in the pulmonary artery. These families of channels, especially the canonical TRP (TRPC) subfamily, may be involved in the development of bronchial hyperresponsiveness, a hallmark of asthma. In the present study, we evaluated i) the effects of sildenafil on tracheal rings of rats subjected to antigen challenge, ii) whether the extent of TRPC gene expression may be modified by antigen challenge, and iii) whether inhibition of type-5 phosphodiesterase (PDE5) may alter TRPC gene expression after antigen challenge. Sildenafil (0.1 µM to 0.6 mM) fully relaxed carbachol-induced contractions in isolated tracheal rings prepared from naive male Wistar rats (250-300 g) by activating the NO-cGMP-K+ channel pathway. Rats sensitized to antigen by intraperitoneal injections of ovalbumin were subjected to antigen challenge by ovalbumin inhalation, and their tracheal rings were used to study the effects of sildenafil, which more effectively inhibited contractions induced by either carbachol (10 µM) or extracellular Ca2+ restoration after thapsigargin (1 µM) treatment. Antigen challenge increased the expression of the TRPC1 and TRPC4 genes but not the expression of the TRPC5 and TRPC6 genes. Applied before the antigen challenge, sildenafil increased the gene expression, which was evaluated by RT-PCR, of TRPC1 and TRPC6, decreased TRPC5 expression, and was inert against TRPC4. Thus, we conclude that PDE5 inhibition is involved in the development of an airway hyperresponsive phenotype in rats after antigen challenge by altering TRPC gene expression.

Controle estatístico de processo univariado: monitoramento da produção de comprimidos de dipirona / Univariate Statistical Process Control: monitoring the production of dipyrone tablets

Investigou-se, através de histogramas e cartas de controle X e S, a ferramenta do Controle Estatístico de Processo (CEP) univariado e os parâmetros físicos dureza, peso médio e friabilidade da produção de dez lotes de dipirona sódica comprimidos. Por sua complexidade e influência no processo, a etapa de granulação de cada lote foi concomitantemente caracterizada através de determinações de densidade bruta, densidade compactada, índice de compressibilidade e fator de Hausner, além dos ângulos de repouso, tempos de escoamento e repartições granulométricas. As caracterizações dos granulados serviram como base na investigação da possível influência da etapa de granulação como uma das prováveis causas que poderiam levar o processo a se apresentar fora de controle estatístico. Os resultados da caracterização indicaram certa uniformidade entre os granulados, o que pode significar que não há ligação aparente entre a etapa de granulação e a falta de controle estatístico do processo, demonstrada na avaliação das cartas de controle. Na medida em que permitiu uma maior compreensão do processo, o CEP univariado mostrou sua importância no monitoramento da produção de comprimidos.

In this study, by means of histograms and and s control charts, the production control tool, univariate Statistical Process Control (SPC), was assessed for monitoring the physical variables hardness, weight and friability during the production of ten batches of sodium dipyrone tablets. In view of its complexity and influence on the process, the granulation step was concurrently characterized by determining the gross density, compacted density, compressibility index and Hausner factor, plus the angle of repose, flow time and particle size distributions of each batch. The properties of the granules were used as a basis for testing the hypothesis that the granulation step is probably the cause when the process runs out of statistical control. The results of the characterization indicated a degree of uniformity among the granules, which may mean that the lack of statistical process control demonstrated in the control charts does not arise from the granulation step. To the extent that it enabled a greater understanding of the process, univariate SCP proved its importance in the monitoring of tablet production.

ApoE polymorphisms and diarrheal outcomes in Brazilian shanty town children

A series of studies have shown that the heavy burdens of diarrheal diseases in the first 2 formative years of life in children living in urban shanty towns have negative effects on physical and cognitive development lasting into later childhood. We have shown that APOE4 is relatively common in shanty town children living in Brazil (13.4 percent) and suggest that APOE4 has a protective role in cognitive development as well as weight-for-height in children with heavy burdens of diarrhea in early childhood (64/123; 52 percent), despite being a marker for cognitive decline with Alzheimer’s and cardiovascular diseases later in life. APOE2 frequency was higher among children with heaviest diarrhea burdens during the first 2 years of life, as detected by PCR using the restriction fragment length polymorphism method, raising the possibility that ApoE-cholesterol balance might be critical for growth and cognitive development under the stress of heavy diarrhea burdens and when an enriched fat diet is insufficient. These findings provide a potential explanation for the survival advantage in evolution of genes, which might raise cholesterol levels during heavy stress of diarrhea burdens and malnutrition early in life.

Apolipoprotein E polymorphism in Brazilian dyslipidemic individuals: Ouro Preto study

The influence of apolipoprotein E alleles and genotypes on plasma lipid levels was determined in 185 individuals of mixed ethnicity living in Ouro Preto, Brazil. DNA was obtained from blood samples and the genotypes were determined by an RFLP-PCR procedure. The *3 allele was the most frequent (72 percent), followed by *4 (20 percent) and *2 (8 percent); *4 frequency was higher and *2 frequency was lower in the dyslipidemic group than in the normal control group. The *2 carriers presented lower LDL and total cholesterol levels compared to the *3 and *4 carriers. All six expected genotypes were observed in the individuals genotyped: E2/2 (2.1 percent), E4/4 (2.7 percent), E2/4 (3.7 percent), E2/3 (8.0 percent), E3/3 (53.3 percent), E3/4 (29.9 percent); no difference in genotype frequencies was found between the normal and dyslipidemic groups. Compared with *2, the presence of *3 increases more than two times the risk for dyslipidemia (OR = 2.31; P = 0.025; 95 percent CI = 1.06-5.06) and the presence of *4 increases it three times (OR = 3.31; P = 0.006; 95 percent CI = 1.36-8.04). The only significant effect of genotype was an increased risk for dyslipidemia in the *4 genotype carriers (E3/4 + E4/4) compared with the *2 genotype carriers (E2/2 + E2/3) with OR = 3.69 (95 percent CI = 1.25-10.88). The present study indicates that in the Ouro Preto admixed population the presence of APOE *2 can confer a protective effect, whereas the presence of APOE *4 implies an enhanced risk for dyslipidemia.

Aplicação do controle estatístico de processo na indústria farmacêutica / The application of statistical process control to the pharmaceutical industry

O controle estatístico de processo (CEP) é uma das mais poderosas metodologias desenvolvidas visando auxiliar no controle eficaz da qualidade. Através das cartas ou gráficos de controle, podem-se detectar desvios de parâmetros representativos do processo, reduzindo a quantidade de produtos fora de especificações e com isso os custos da produção. O controle estatístico de processo embora pouco utilizado na indústria farmacêutica, é uma ferramenta de grande utilidade, pois incorpora também o conceito de boas práticas de fabricação, além de fornecer informações imprescindíveis para a validação de processos, uma vez que permitem a investigação detalhada de todos os pontos críticos de controle, diagnosticando as possíveis não conformidades em todas as etapas do processo, além de sinalizar as possíveis fontes desses desvios de qualidade possibilitando correções e interações com o processo. Apesar de não existir muitas publicações do CEP na indústria farmacêutica, os exemplos de aplicações desta ferramenta provam sua grande importância para a compreensão dos processos que envolvem a obtenção de medicamentos

Thalidomide and pentoxifylline block the renal effects of supernatants of macrophages activated with Crotalus durissus cascavella venom

Because thalidomide and pentoxifylline inhibit the synthesis and release of tumor necrosis factor-alpha (TNF-alpha), we determined the effect of these drugs on the renal damage induced by supernatants of macrophages activated with Crotalus durissus cascavella venom in order to identify the role of TNF-alpha in the process. Rat peritoneal macrophages were collected with RPMI medium and stimulated in vitro with C.d. cascavella venom (10 µg/ml) in the absence and presence of thalidomide (15 µM) or pentoxifylline (500 µM) for 1 h and washed and kept in culture for 2 h. Supernatant (1 ml) was tested on an isolated perfused rat kidney (N = 6 for each group). The first 30 min of each experiment were used as control. The supernatant was added to the perfusion system. All experiments lasted 120 min. The toxic effect of the preparation of venom-stimulated macrophages on renal parameters was determined. At 120 min, thalidomide (Thalid) and pentoxifylline (Ptx) inhibited (P < 0.05) the increase in perfusion pressure caused by the venom (control = 114.0 ± 1.3; venom = 137.1 ± 1.5; Thalid = 121.0 ± 2.5; Ptx = 121.4 ± 4.0 mmHg), renal vascular resistance (control = 4.5 ± 0.2; venom = 7.3 ± 0.6; Thalid = 4.5 ± 0.9; Ptx = 4.8 ± 0.6 mmHg/ml g-1 min-1), urinary flow (control = 0.23 ± 0.001; venom = 0.44 ± 0.01; Thalid = 0.22 ± 0.007; Ptx = 0.21 ± 0.009 ml g-1 min-1), glomerular filtration rate (control = 0.72 ± 0.06; venom = 1.91 ± 0.11; Thalid = 0.75 ± 0.04; Ptx = 0.77 ± 0.05 ml g-1 min-1) and the decrease in percent tubular sodium transport (control = 77.0 ± 0.9; venom = 73.9 ± 0.66; Thalid = 76.6 ± 1.1; Ptx = 81.8 ± 2.0 percent), percent tubular chloride transport (control = 77.1 ± 1.2; venom = 71.4 ± 1.1; Thalid = 77.6 ± 1.7; Ptx = 76.8 ± 1.2 percent), and percent tubular potassium transport (control = 72.7 ± 1.1; venom = 63.0 ± 1.1; Thalid = 72.6 ± 1.0; Ptx = 74.8 ± 1.0 percent), 30 min before and during the stimulation of macrophages with C.d. cascavella venom. These data suggest the participation of TNF-alpha in the renal effects induced by supernatant of macrophages activated with C.d. cascavella venom.

Hepatitis C virus infection among Brazilian hemophiliacs: a virological, clinical and epidemiological study

We determined and analyzed risk factors of hepatitis C virus (HCV)-infected Brazilian hemophiliacs according to their virological, clinical and epidemiological characteristics. A cross-sectional and retrospective study of 469 hemophiliacs was carried out at a Brazilian blood center starting in October 1997. The prevalence of HCV infection, HCV genotypes and factors associated with HCV RNA detection was determined. The seroprevalence of anti-HCV antibodies (ELISA-3.0) was 44.6 percent (209/469). Virological, clinical and epidemiological assessments were completed for 162 positive patients. There were seven (4.3 percent) anti-HCV seroconversions between October 1992 and October 1997. During the same period, 40.8 percent of the positive anti-HCV hemophiliacs had abnormal alanine transaminase (ALT) levels. Plasma HCV RNA was detected by nested-RT-PCR in 116 patients (71.6 percent). RFLP analysis showed the following genotype distribution: HCV-1 in 98 hemophiliacs (84.5 percent), HCV-3 in ten (8.6 percent), HCV-4 in three (2.6 percent), HCV-2 in one (0.9 percent), and not typeable in four cases (3.4 percent). Univariate analysis indicated that older age (P = 0.017) and abnormal ALT levels (P = 0.010) were associated with HCV viremia, while the presence of inhibitor antibodies (P = 0.024) and HBsAg (P = 0.007) represented a protective factor against the presence of HCV RNA. These findings may contribute to a better understanding of the relationship between HCV infection and hemophilia

Estudo da fosfatase alcalina em ratos cirróticos hepatectomizados após aplicaçäo de laser / Study of alkalin fosfatase in cirrhotic and hepatectomized rats after laser application

O presente estudo tem por objetivo verificar o comportamento da fosfatase alcalina sobre o fígado cirrótico, submetido à hepatectomia ou näo, após a aplicaçäo de laser. A cirrose hepática foi induzida em ratos Wistar por ligadura do ducto biliar comum durante 4 semanas. Os resultados revelaram que em todos os grupos cirróticos os valores da FA foram maiores que o controle, mas entre os grupos cirróticos näo houve diferença.

Estudo do potencial de membrana mitocondrial em ratos cirróticos hepatectomizados após aplicaçäo de laser / Study of mitochondrial membrane potential in cirrhotic and hepatectomized rats after laser application

Através da determinaçäo do potencial de membrana mitocondrial, o presente estudo relata os efeitos da irradiaçäo laser sobre o estado energético do fígado cirrótico de ratos hepatectomizados. A cirrose hepática foi induzida por ligadura do ducto biliar comum. Os resultados revelaram melhora do status energético do fígado após irradiaçäo.

Método de induçäo de cirrose biliar secundária com uso de prótese de silicone / Method for the induction of secundary bibliary cirrhosis with use of silicone prosthesis

O objetivo deste experimento foi o desenvolvimento de um modelo de obstruçäo do ducto biliar comum através da interposiçäo de uma prótese de silicone extrínseca ao ducto com única ligadura sem secçäo. Desenvolveu-se um modelo experimental alternativo, em ratos Wistar, que provoca a interrupçäo do fluxo bílio-duodenal com resultado satisfatório, pois houve distorçäo da arquitetura hepática, caracterizada por fibrose e proliferaçäo ductal além de indicadores bioquímicos da colestase.

Estudo das aminotransferases em ratos cirroticos hepatectomizados após aplicaçäo de laser / Study of aminotransferases in cirrhotic and hepatectomized rats after laser application

Através do estudo das aminotransferases, este trabalho investiga os efeitos da irradiaçäo laser como agente lesivo ao fígado cirrótico de ratos hepatectomizados. A cirrose hepática foi induzida por ligadura do ducto biliar comum. Os resultados revelaram ausência de lesäo hepática adicional nos grupos cirróticos após irradiaçäo.

Aspecto funcional do remanescente hepático em condiçöes de isquemia e reperfusäo após hepatectomia parcial / Functional aspects of hepatic remmanescent in ischemia and reperfusion condiction after parcial hepatectomy

O efeito da hipotermia, precondicionamento isquêmico e drogas protetoras das lesöes de isquemia e reperfusäo têm sido amplamente estudado. O objetivo do presente estudo é avaliar os efeitos da deferoxamina na isquemia e reperfusäo sobre o fígado remanescente após ressecçäo hepática parcial a 70 por cento, avaliando-se a funçäo mitocondrial hepática. Estudou-se 34 ratos divididos em grupos: Grupo HP (n = 8) - submetidos a hepatectomia parcial (HP) a 70 por cento; Grupo HPD (n = 4) - submetidos a administraçäo de deferoxamina (40 mg/kg) e HP a 70 por cento; Grupo HPI (n = 7) - hepatectomizados (HP a 70 por cento) e submetidos a isquemia (40 minutos); Grupo HPID (n = 7) - semelhante ao anterior, porém recebendo previamente deferoxamina; Grupo C (n = 8) - controle, submetido a operaçäo simulada para HP a 70 por cento. A análise estatística entre os diversos grupos foi feita pelos testes de Kruskal - Wallis e de Mann - Whitney, com nível de significância de 5 por cento. Dessa maneira, o estado III foi semelhante em todos os procedimentos; o estado IV: C

Measurement of intestinal permeability using mannitol and lactulose in children with diarrheal diseases

The excretion ratio of lactulose/mannitol in urine has been used to assess the extension of malabsorption and impairment of intestinal permeability. The recovery of lactulose and mannitol in urine was employed to evaluate intestinal permeability in children with and without diarrhea. Lactulose and mannitol probes were measured using high-performance liquid chromatography with pulsed amperometric detection (HPLC-PAD). Two groups of solutions containing 60 µM sugars were prepared. Group I consisted of glucosamine, mannitol, melibiose and lactulose, and group II of inositol, sorbitol, glucose and lactose. In the study of intra-experiment variation, a sample of 50 µl from each group was submitted to 4 successive determinations. The recovered amounts and retention times of each sugar showed a variation <2 and 1 per cent, respectively. The estimated recovery was >97 per cent. In the study of inter-experiment variation, we prepared 4 independent samples from groups I and II at the following concentrations: 1.0, 0.3, 0.1, 0.03 and 0.01 mM. The amounts of the sugars recovered varied by <10 per cent, whereas the retention times showed an average variation <1 per cent. The linear correlation coefficients were >99 per cent. Retention (k'), selectivity (a) and efficiency (N) were used to assess the chromatographic conditions. All three parameters were in the normal range. Children with diarrhea presented a greater lactulose/mannitol ratio compared to children without diarrhea.