Duodenogastric reflux potentiates the injurious effects of gastroesophageal reflux

Experimental studies have shown that the severity of esophageal mucosal injury in gastroesophageal reflux disease is related to the reflux of both gastric and duodenal juice. The purpose of this study was to determine whether duodenal juice potentiates esophageal injury in patients with reflux disease or, in fact, causes no harm allowing acid and pepsin to do the damage. A total of 148 consecutive patients who had no previous gastric or esophageal surgery underwent endoscopy and biopsy, manometry, and 24-hour esophageal pH and bilirubin monitoring. Esophageal injury was defined by the presence of erosive esophagitis, stricture, or biopsy-proved Barrett's esophagus. Exposure to duodenal juice, identified by the absorbance of bilirubin, was defined as an exposure time exceeding the ninety-fifth percentile measured in 35 volunteers. To separate the effects of gastric and duodenal juice, patients were stratified according to their acid exposure time. One hundred patients had documented acid reflux on pH monitoring, and in 63 of them it was combined with reflux of duodenal juice. Patients with combined reflux (50 of 63) were more likely to have injury than patients without combined reflux (22 of 37; P < 0.05). When the acid exposure time was greater than 10%, patients with injury (n = 40) had a greater exposure to duodenal juice (median exposure time 17.2% vs. 1.1%, P = 0.006) than patients without injury (n = 5), but there was no difference in their acid exposure (16.9% vs. 13.4%). Patients with dysplasia of Barrett's epithelium (n = 9) had a greater exposure to duodenal juice (median exposure time 30.2% vs. 7.2%, P = 0.04) compared to patients without complications (n = 25), whereas acid exposure was the same (16.4% vs. 15%). Duodenal juice adds a noxious component to the refluxed gastric juice and potentiates the injurious effects of gastric juice on the esophageal mucosa.     

Constrained image reconstruction for magnetic detection electrical impedance tomography

Magnetic detection electrical impedance tomography (MD‐EIT) produces images of conductivity from magnetic field measurements taken around the body. The ill‐conditioned nature of the MD‐EIT inverse problem is improved by limiting the number of unknowns to be solved. In this article, a method of iterative grid refinement for MD‐EIT, which produces images significantly better than unconstrained solutions, is described. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 379–382, 2007     

HIV/AIDS risk in heterosexual college students. A review of a decade of literature

Empirical studies dealing with the psychosocial correlates of HIV risk among heterosexual college students are reviewed, including findings related to such theoretical variables as HIV/AIDS-related knowledge, personal and partner's attitudes toward condom use, perceived susceptibility, communication with sex partners, and sexual self-efficacy. Although college students are highly knowledgeable about basic HIV/AIDS facts, they retain some misperceptions about disease transmission. They hold neutral-to-negative hedonistic and practical attitudes about using condoms: those who have engaged in risky behavior accurately perceive their greater susceptibility to infection and experience anxiety regarding transmission of HIV infection. Heterosexual college students communicate infrequently with their partners about safer sex, but they often agree to a partner's suggestion that they use condoms. Higher levels of sexual self-efficacy among college students have been associated with a lower risk for HIV transmission. Limitations and clinical implications of the findings and recommendations for future interventions are discussed.     

Is the quest for evidence-based care detrimental to children's nursing?

Evidence-based care and the expanded role of the nurse are inexorably linked. Facets of this are found in every specialist area of nursing. Children's nurses are no exception and they have proved their commitment to family-centred care over a period of many years. However, within the ranks of nurse educationalists now employed by the universities and not the NHS new tensions have emerged. The research-led ethos of the universities demands that nurses demonstrate expertise in the field of scientific enquiry. Although the philosophy of caring and research are not incongruent, there exists the potential that family empowerment may take a back seat to academic prowess. This article examines the background to this dilemma.     

Dysplasia in Barrett's esophagus: diagnosis, surveillance and treatment

Barrett's esophagus is a premalignant metaplastic change in the lining of the distal esophagus. It represents a peculiar form of healing which occurs in response to chronic gastroesophageal reflux disease. The condition should be considered in all patients undergoing endoscopy for symptoms of reflux disease and is confirmed when any biopsy shows the presence of specialized intestinal metaplasia irrespective of the macroscopic appearance of the distal esophagus. Endoscopic surveillance with multiple biopsy sampling of the esophageal mucosa is indicated for all medically fit patients with Barrett's esophagus. The diagnosis of dysplastic change within this abnormal mucosa requires histological examination of the biopsies by 2 independent but experienced pathologists. Identification of high-grade dysplasia heralds the development of invasive cancer and offers the physician an opportunity to intervene. Despite extensive endoscopic sampling of the esophageal mucosa the differentiation between high-grade dysplasia and invasive adenocarcinoma is unreliable. Esophagectomy remains the treatment of choice for patients with high-grade dysplasia since adenocarcinoma of the esophagus carries such a poor prognosis.     

Rare-earth element anti-Stokes emission from three inverse photonic lattices

The fabrication of a two-dimensional photonic lattice of ZrO₂:Er³⁺ on a silicon substrate and two three-dimensional photonic lattices, ZrO₂:Eu³⁺ and TiO₂:Er³⁺, are described. It is demonstrated that, for the two-dimensional lattice, photonic properties dependent on the lattice are not present, although another effect that was dependent on the structure is discussed. For the two three-dimensional photonic lattices, the position of the photonic stopband relative to the emission bands of the anti-Stokes phosphors is shown to be crucial in controlling emission properties. In the case of the ZrO₂:Eu³⁺ lattice, where the stopband was close to both the emission and the exciting wavelengths, the intensities of both were affected. However, for the TiO₂:Er³⁺ lattice, where the stopband was far from the exciting and emission wavelengths, no such effect was seen. It was concluded from this work that it should be possible to prepare unconverting photonic lattices with stopbands that extend the lifetimes of certain excited states by inhibiting spontaneous emission from them, thereby facilitating enhanced upconversion efficiency.     

An investigation into the ability of soft drinks to adhere to enamel

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.     

Selection, dominance and atresia of follicles during the oestrous cycle of heifers

This study examined the correlation between measurement of follicle growth by ultrasound, and measurement of intrafollicular ratios of oestradiol and progesterone concentrations and the serum concentrations of FSH during selection, dominance and atresia or ovulation of dominant follicles in heifers. Heifers were ovariectomized on days 0 (before LH surge), 1 (after LH surge, preovulation), 1 (postovulation), 3, 6 and 12 of the oestrous cycle. Blood samples were collected at 4-6 h intervals. After ovariectomy all follicles > or = 5 mm were measured and follicular fluid was aspirated. Follicles were classified by size according to ultrasound (F1, largest; F2, second largest; F3, all remaining follicles > or = 5 mm) and by the ratio of oestradiol:progesterone concentrations. During the follicular phase, a single dominant oestrogen-active follicle increased in diameter while serum concentrations of LH increased and FSH decreased (P < 0.05). On day 1 (after LH surge, preovulation), serum LH and FSH decreased to pre-surge concentrations (P < 0.0001), while follicle size and intrafollicular progesterone concentration increased and oestradiol concentration decreased (P < 0.05). A dominant nonovulatory follicle, classified as oestrogen-active on days 1, 3 and 6 and oestrogen-inactive on day 12, increased in size from day 1 to day 7 and lost dominance during days 10-12, coincident with the growth of multiple oestrogen-active follicles. The serum FSH concentration increased transiently (P < 0.05) before each new wave of dominant follicular growth. The overall correlation of ultrasound measurements of follicle diameter with measures of follicle size after ovariectomy was high.(ABSTRACT TRUNCATED AT 250 WORDS)     

A Comparison of the Properties of Some Chloramphenicol and Neomycin Eye Ointments, Commercially Available in the U.K

The rheology, particle size distribution and drug release, measured by dissolution and agar diffusion techniques, of five B.P. Chloramphenicol Eye Ointments and three B.P. Neomycin Eye Ointments have been examined. All ointments showed structural breakdown during continuous shear rheology. Three chloramphenicol ointments displayed spur values whilst one neomycin ointment displayed a bulge on the up-curve of the rheogram. Mass median particle sizes ranged from 6.0 to 13.0 and 5.4 to 9.6 μm for the chloramphenicol and neomycin ointments respectively. Drug release similarly varied. By dissolution techniques the quantity of chloramphenicol that dissolved in 60 minutes ranged from 22 to 41 μg whilst agar diffusion studies produced drug releases which varied from 2.4 to 4.7 and 0.8 to 2.3 μg for the chloramphenicol and neomycin results respectively.