Effect of Ramadan fasting on intragastric pH recorded during 24 hours in healthy subjects

OBJECTIVES: Lifestyle changes during Ramadan as the meals are taken exclusively in the evening, and nightly sleep is often delayed and shortened. The wake/sleep cycle is also modified. The aim of this study was to evaluate the influence of Ramadan on gastric acidity in healthy volunteers. METHODS: Nine healthy volunteers had 24-hour measurement of the gastric pH; 4 periods were compared: one week prior to Ramadan, day 10 and day 24 during Ramadan, and one month after Ramadan. The pH profiles and the [H+] activity (area under the curve) were measured during 24 hours, the night phase (5PM-8AM) and diurnal phase (8AM-5PM). RESULTS: The diurnal variations of the pH profile were more significant; the median pH was 2.3 prior to Ramadan, 1 at day 10 and day 24 and 1.6 one month after Ramadan. The 24-hours [H+] activity increased by 45% at day 10 of Ramadan compared with its level prior to Ramadan. This increase was mostly diurnal (+122%) and also nightly (+25%). The activity [H+] was steady during Ramadan. One month after Ramadan, the 24-hours [H+] activity was 23% higher than the one noted before Ramadan. CONCLUSIONS: This study shows that the conditions of feeding imposed by Ramadan are associated with an increase of the gastric acidity mainly in diurnal phase. These results do not explain the origin of the healthy volunteer digestive symptoms encountered during Ramadan.     

The diagnosis of ventilator-associated pneumonia: a comparison of histologic, microbiologic, and clinical criteria

STUDY OBJECTIVE: To evaluate histologic, microbiological, and clinical criteria in the recognition of ventilator-associated pneumonia (VAP) in patients who died while mechanically ventilated. METHODS: The study group consisted of 39 patients who died after a mean of 14 days of mechanical ventilation. Postmortem fiberoptic bronchoscopy (FOB) and open lung biopsy were performed with collection of specimens initiated <1 h after death. The microbiological specimens included suction catheter aspirate of tracheal secretions, FOB-guided protected specimen brush (PSB) of tracheal secretions, blindly placed PSB in a distal airway, FOB-guided PSB in a distal airway, and FOB-guided BAL fluid (BALF) in a distal airway. Qualitative bacteriologic study was performed on all specimens, and quantitative bacteriologic study was performed on all but the suction catheter aspirate of the trachea. A biopsy specimen of peripheral lung parenchyma from the same region sampled by FOB was sent for quantitative culture and histologic analysis. The BALF was analyzed for cell population and percent of neutrophils containing intracellular organisms. The clinical criteria selected for comparison with histologic and microbiological results included a temperature > or =38.5 degrees C during the 48 h prior to death, a WBC count > or =15,000/mm3 in the 48 h prior to death, presence of a bacterial or fungal pathogen on the last sputum culture, radiographic worsening in the week prior to death, and worsening gas exchange defined as a 15% decrease in the PaO2/fraction of inspired oxygen ratio in the 72 h prior to death. RESULTS: None of the quantitative cultures had a reliable positive predictive value for histologic pneumonia. None of the five clinical criteria tested showed agreement with the presence or absence of histologic pneumonia. There was a significant correlation between qualitative and quantitative microbiological results from the distal airway/FOB-guided PSB, distal airway/BALF, and quantitative culture of the lung parenchyma. Also, suction catheter aspirate of the trachea had a sensitivity of 87% in recognizing the bacterial species simultaneously present in lung parenchyma. None of the patients with histologic pneumonia had <50% neutrophils in the BALF. CONCLUSIONS: Neither the bacterial, density from the four airway quantitative cultures, nor the bacterial density from quantitative culture of lung parenchyma accurately separated the histologic pneumonia and nonpneumonia groups. No clinical criteria or combination of clinical criteria correlated with the presence or absence of histologic pneumonia. A BALF with <50% neutrophils had a 100% negative predictive value for histologic pneumonia. A BALF quantitative culture had a sensitivity of 63%, specificity of 96%, and positive predictive value of 91% in recognizing sterile lung parenchyma. Thus, BALF may have a role in excluding pneumonia/infection in the ventilated patient. Antibiotic choice for the empiric therapy of VAP can be accurately guided by the microbial population recognized through culture of a tracheal suction catheter aspirate.     

Trends in HIV-1 prevalence may not reflect trends in incidence in mature epidemics: data from the Rakai population-based cohort, Uganda

OBJECTIVES: To assess whether trends in serial HIV-1 prevalence reflect trend in HIV incidence, and to decompose the effects of HIV-1 incidence, mortality, mobility and compliance on HIV-1 prevalence in a population-based cohort. DESIGN: Two-year follow up (1990-1992) of an open cohort of all adults aged 15-59 years, resident in a sample of 31 representative community clusters in rural Rakai District, Uganda. METHODS: A detailed household enumeration was concluded at baseline and in each subsequent year. All household residents were listed, and all deaths and in- and out-migrations that occurred in the intersurvey year wee recorded. In each year, all consenting adults were interviewed and provided a serological sample; 2591 adults aged 15-59 years were enrolled at baseline. RESULTS: HIV prevalence among adults declined significantly 1990 and 1992 (23.4% at baseline, 21.8% in 1991, 20.9% in 1992; P < 0.05). Declining prevalence was also observed in subgroups, including young adults aged 15-24 years (from 20.6 to 16.2% over 3 years; P < 0.02), women of reproductive age (from 27.1 to 23.5%; P < 0.05), and pregnant women (from 25.4 to 20.0%; not significant), However, HIV incidence did not change significantly among all adults aged 15-59 years (2.1 +/- 0.4 per 100 person-years of observation (PYO) in 1990-1991 and 2.0 +/- 0.3 per 100 PYO in 1991-1992], nor in population subgroups. HIV-related mortality was high (13.5 per 100 PYO among the HIV-positive), removing more infected persons that were added by seroconversion. Net out-migration also removed substantial numbers of HIV-positive individuals. CONCLUSIONS: In this mature HIV epidemic, HIV prevalence declined in the presence of stable and incidence. HIV-related mortality contributed most to the prevalence decline. Prevalence was not an adequate surrogate measure of incidence, limiting the utility or serial prevalence measures in assessing the dynamics of the HIV epidemic and in evaluating the impact of current preventive strategies.     

Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin induce intrachromosomal recombination in vitro and in vivo

Polychlorinated aromatic hydrocarbons such as polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are extremely stable and widely distributed environmental pollutants. These chemicals are animal carcinogens and probable human carcinogens, and TCDD is possibly one of the most potent toxins ever evaluated by the United States Environmental Protection Agency. Polychlorinated aromatic hydrocarbons score negatively in most genotoxicity assays, including the Ames (Salmonella) assay. Although their mechanism of toxicity is not well understood, they induce aryl hydrocarbon (AH) hydroxylases and bind to the AH receptor, which is believed to mediate toxicity. Here, we determine effects of polychlorinated aromatic hydrocarbons in genotoxicity assays that score for DNA deletions by intrachromosomal recombination in vivo and in vitro. In this study, TCDD, Aroclor 1221, and Aroclor 1260 induced deletions in vivo in the mouse embryo; Aroclor 1221 and Aroclor 1260 induced deletions in yeast. We also show that the induced deletion events did not correlate with induction of AH hydroxylase. None of the tested compounds induced CYP1A-associated ethoxyresorufin-O-deethylase activity in mouse embryos or in vitro. These results clearly demonstrate a genotoxic activity of polychlorinated aromatic hydrocarbons in vitro and in vivo, which is independent of induction of cytochrome P450 activity. Because genetic instability and deletions may be mechanistically involved in carcinogenesis, these results may encourage further research to determine whether such genotoxic mechanisms may be useful for cancer risk assessment of polychlorinated aromatic hydrocarbons.     

Effects of high dose octreotide on retrograde bile salt-induced pancreatitis in rats

The effects of somatostatin and octreotide (a long acting somatostatin analogue) in acute pancreatitis are inconclusive. This study examined the prophylactic and therapeutic effects of different doses of octreotide on retrograde sodium taurodeoxycholate-induced acute necrotizing pancreatitis in rats. The rats were divided into 4 groups receiving subcutaneous injection of saline, octreotide 10 microg/kg, 20 microg/kg at 0, 8 and 16 h and octreotide 20 microg/kg at 5, 13 and 21 h, separately. The serum levels of amylase and lipase, pancreatic histopathology, mortality and hemodynamics were examined. Octreotide significantly reduced serum levels of amylase and lipase at 12 h and the degree of pancreatic edema, necrosis and hemorrhage at 18-24 h as compared to the control group. Prophylactic octreotide 10 microg/kg significantly decreased the 24-h mortality from 100% to 44.4% (p < 0.05). The 24-h mortality further reduced to 12.5% and 10% with prophylactic and therapeutic octreotide 20 microg/kg, respectively. The decrease of mean arterial pressure at 12 h was significantly lower in octreotide groups than in the control group. We conclude that octreotide improves pancreatic histopathology and survival in acute necrotizing pancreatitis in rats.     

The first subcomponent of complement, C1q, triggers the production of IL-8, IL-6, and monocyte chemoattractant peptide-1 by human umbilical vein endothelial cells

We and others have demonstrated previously the occurrence of cC1qR/CaR, a receptor for the collagen-like stalks of complement component C1q, on endothelial cells. In the present study we investigated whether binding of C1q to endothelial cells resulted in enhancement of cytokine or chemokine production. HUVEC produced 82 +/- 91 pg/ml of IL-8, 79 +/- 113 pg/ml of IL-6, and 503 +/- 221 pg/ml of monocyte chemoattractant peptide-1 (MCP-1) under basal conditions. Incubation with C1q resulted in a time- and dose-dependent up-regulation of IL-8 (1012 +/- 43 pg/ml), IL-6 (392 +/- 20 pg/ml), and MCP-1 (2450 +/- 101 pg/ml). This production is dependent on de novo protein synthesis, as demonstrated by the detection of specific mRNA after C1q stimulation, and inhibition of peptide production in the presence of cycloheximide. The production of all factors was inhibited (69 +/- 7%) by the collagenous fragments of C1q, while the C1q globular heads only induced 13 +/- 11% inhibition. When HUVEC were incubated with C1q in the presence of aggregated IgM, enhanced production of IL-8 (2500 +/- 422 pg/ml), IL-6 (997 +/- 21 pg/ml), and MCP-1 (5343 +/- 302 pg/ml) was found. Furthermore, F(ab')2 anti-calreticulin partially inhibited the production of IL-8, confirming at least the involvement of cC1qR/CaR. These experiments suggest that in an inflammatory response C1q not only is able to activate the complement pathway, but when presented in a proper fashion also might induce the production of factors that contribute to acute phase responses and recruitment of inflammatory cells.     

Rapid recurrence of Helicobacter pylori infection in Peruvian patients after successful eradication. Gastrointestinal Physiology Working Group of the Universidad Peruana Cayetano Heredia and The Johns Hopkins University

Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. Since gastric cancer is common in Peru, eradication of H. pylori may help to reduce the occurrence of gastric cancer. This study involved three randomized trials to determine the efficacy of four different triple-drug therapy regimens. The most successful regimen was furazolidone combined with bismuth subsalicylate and amoxicillin, which eradicated infection in 82% of patients. Patients successfully treated were followed every 2-3 months to determine the recurrence rate of H. pylori infection. Of 105 patients with H. pylori eradication documented by pathology and culture, 52% (55) returned for follow-up endoscopy, and in 73% (40) of these 55 the infection recurred during the 8-month follow-up period. Thirty-five patients from whom H. pylori was eradicated and who were tested for antibodies to H. pylori remained consistently seropositive. Rapid recurrence of H. pylori infection after successful eradication suggests that measures other than antimicrobial therapy are needed to fight H. pylori in developing countries.     

Crohn's disease of the larynx

Extraintestinal involvement of Crohn's disease is becoming more readily identified. Laryngeal involvement by Crohn's disease, however, has been reported in only five cases in the medical literature. We present the sixth case as well as an analysis of the prior reports.     

Extravisceral masses in the peritoneal cavity: sonographically guided biopsies in 52 patients

To establish a possible correlation between the rate of cellular proliferation and already documented functional and morphological characteristics of the rat pineal gland during postnatal development, the bromodeoxyuridine labelling method was used to evaluate the fraction of cells at the S phase of the cell cycle in paraffin sections from 1-, 7-, 14- and 28-day-old rats. Numerical density, taken as an indirect measure of cell hypertrophy, was also evaluated. During the first week after birth the percentage of S phase-cells in the rat pineal gland sharply decreased from around 9% to 1.3%. A smaller but also significant decrease was found from the 7th to the 14th postnatal day where S phase cells were less than 0.5% of all pineal cells. A very low percentage was also seen in samples from 28-day-old rats. Numerical density, namely, the total number of cells per surface unit of pineal section, decreased from birth to the end of the first month. This decrease was also steeper from birth to the 7th postnatal day than at any other period of the study. These results support the idea that a strong expansion of the cellular population of the rat pineal gland precedes morphological and functional maturation and opens the way to further exploration of the relationship between functional and proliferative responses of the pineal gland.