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A cellulose microfluidic pH boosting layer adapts a non-enzymatic copper oxide glucose sensor strip for neutral pH samples. This adaptation allows the non-enzymatic technology to realize in-situ glucose measurements. A three-electrode system is constructed to test samples in a classical electrochemical cell, and in a sensing strip to test the microfluidic system. The system consists of copper oxide as working electrode, and silver and carbon paints as reference, and counter electrodes, respectively. The fabrication of the pH-boosting layer is made with natural cellulose. Within this layer are NaOH crystals, grown by a drying processes after immersion of cellulose in a concentrated solution of NaOH. The microfluidic layer is placed on top of the sensing electrodes, and while it transports the fluid sample to the sensing electrodes, the fluid dissolves the NaOH crystals, increasing the pH of the sample. This change allows the non-enzymatic mechanism to sense the glucose concentration in the fluid. Our system shows the capability to measure glucose in samples with neutral pH and human blood with a sensitivity of 70 µA/mM cm2, enough to distinguish between hypoglycemia and hyperglycemia.

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Two species of Phthiraptera, Bovicola caprae (Ischnocera: Bovicolidae) and Solenopotes binipilosus (Anoplura: Linognathidae), and one species of mite, Psoroptes ovis (Acari: Psoroptidae), were recorded on huemul (Hippocamelus bisulcus) in Chile. The sucking louse S. binipilosus and the mite P. ovis are reported for the first time from this host.

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Fermentation conditions and microorganisms were determined, based on acid production, glucose concentration as carbohydrate source. Inoculation levels to obtain a stable shrimp waste silage were also determined. Shrimp waste ensilation was an efficient method of preservation, allowing the recovery of chitin and another added-value products such as pigments, proteins and enzymes. From the various lactic acid bacteria tested, Lactobacillus pentosus and Lactobacillus sp. (B2) were the best lactic acid producers, although small quantities of acetic acid were detected in samples inoculated with Lactobacillus pentosus. Therefore B2 was chosen for the analysis of glucose consumption as well as for the determination of optimum inoculation levels. The best results were obtained at 10% (w/w wet basis) and 5% (v/w wet basis) respectively. Presence of starters and initial glucose concentration were critical factors in the fermentation of shrimp waste. High initial glucose and starter concentrations reduced the time and increased the amount of lactic acid produced. The fermentation pattern changed during ensilation from hetero to homofermentative. Shrimp waste ensilation prevented the growth of spoilage microorganisms keeping their microbial counts steady and pH values within the acid region.

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The aim of this study was to evaluate the utility of a volume-modified blood culture system to diagnose bacteremia in newborns and infants. A total of 793 paired blood cultures, obtained from 464 patients (173 newborns and 291 infants), were analyzed. Vacutainer tubes containing 18 ml supplemented peptone broth sodium-polyanethol-sulfonate were used as the gold standard, in comparison with a blood micro-culture system containing 1.8 ml of the broth. Prior to antibiotic treatment, 2.2 ml of blood was obtained from each patient; 0.2 ml was inoculated in a blood micro-culture tube and 2 ml in a routine tube. Sensitivity, specificity and predictive values were calculated. Microorganisms were isolated in 153 standard blood culture tubes and 151 blood micro-culture tubes. The sensitivity of the blood micro-culture system was 95%, specificity 99% and positive and negative predictive values 96% and 99% respectively. The sensitivity and specificity of blood micro-culture in neonates and infants is high. We recommend that this system be used for the diagnosis of bacteremia in newborns and infants in laboratories where manual systems are still in use.

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We describe retrospectively the experience with 44 cases of AIDS from January 1987 to October 1991 at the Instituto Nacional de Pediatria, a tertiary care children hospital in Mexico City. All patients with 2 ELISA and a positive Western Blot test were included. Thirty three patients were infected perinatally (75%) and 11 through blood transfusion (25%). Fourty one patients belonged to the P2 classification of the Centers for Disease Control. Chronic diarrhea (77%), lymphadenopathy (75%), hepatomegaly/splenomegaly (70%) and oral candidiasis (61%) were the most common clinical findings. Twenty patients died (45.4%). No statistical relation were found between survival rate and the way of transmission and age at onset. Autopsy was performed in 14 patients and revealed a sharp decrease of lymphoid tissue at all levels with severe thymic atrophy.

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Diarrhoea is a common illness and can be life-threatening. Mothers are used to dealing with diarrhoea and have an ample repertoire of home-based practices, traditional treatments, and western-style medicine to manage diarrhoeal episodes. However, programme planners often overlook and/or underestimate this knowledge, and by so doing they constrain the possible impact of educational messages and intervention programmes designed to treat diarrhoea and to promote oral rehydration therapy. This study addresses the "popular epidemiology" of diarrhoea, in an effort to highlight data that may prove useful for planners of diarrhoea-management programmes. We found that when mothers assess the severity of diarrhoea they consider an increase in the usual number of stools passed per day, as well as the colour, smell and liquid content of the stools. However, they also place special consideration on how much the episode of diarrhoea interfered with their daily activities. When considering the worsening or improvement of their child during the episode, they rely on symptoms related to changes in the child's usual wellbeing, while the more important signs that they recognise are focused on the child's eyes. In relation to fluid and food, we found that herbal tea and rice-based beverages were most commonly used, and that during diarrhoea, mothers were more prone to modify the usual diet fed to the child than to withhold food.

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