Comparative evaluation of surface deposits on high water content hydrogel contact lens polymers

Twenty soft contact lens wearers were fit with a high water content, non-HEMA (ofilcon A) lens (Durasoft 4; Wesley-Jessen) on the test eye. Patients subsequently wore one of the following four lenses on the same eye: a high-water content non-HEMA (surfilcon A) lens (Permaflex 74; CooperVision); a modified mid-water content HEMA (bufilcon A) lens (Hydrocurve Elite; Sola/Barnes-Hind); a low-water content HEMA (polymacon) lens (O4; Bausch & Lomb); or a low-water content non-HEMA (crofilcon A) lens (CSI; Sola/Barnes-Hind). All lenses were worn on a daily wear basis for one month and then evaluated with the scanning electron microscope (SEM). The amount of surface deposition was measured in terms of the area of lens covered by deposit as visualized on a standard series of SEM photographs. When control was obtained for patient, eye, technique, care system, and wearing time, similar amounts of deposit were found on the two high water content soft lenses. A significantly greater amount of deposit was found on the non-HEMA high water content ofilcon A lens compared to the mid-water content modified HEMA material. However, when the patient's tendency to produce "heavy" or "light" deposits on a soft lens surface is taken into account, then for the lighter depositors the high water content non-HEMA material was found to be as acceptable as the low water content HEMA and non-HEMA materials. But for heavy depositors the high water content non-HEMA material is not recommended.     

A comparative study of tear evaporation rates and water content of soft contact lenses

Tear evaporation rates were measured by resistance hygrometry in a group of five subjects wearing soft contact lenses ranging in initial water content from 38 to 70%. The water content of the lenses before and after wear was measured by a "wet blot weighing" technique using a chemical balance. The placing of all types of soft lenses on the eye disrupts the tear film sufficiently to produce significant increases in evaporation. This increase in tear evaporation was not found to be related to the initial water content of the soft lens. Water lost by dehydration of the lens material made a relatively minor contribution to the increase in evaporation from the eye during lens wear.     

The effect of urapidil on responses to phenylephrine,angiotensin and isoprenaline in man

Summary Intravenous urapidil, 40 mg bolus followed by an infusion of 18 mg·h^–1 for 2 h was administered to 6 female non-patient volunteers. Randomised cumulative dose response curves to angiotensin, phenylephrine and isoprenaline were performed before and commencing 30 min after the start of the infusion of urapidil. Urapidil significantly reduced supine systolic blood pressure, 118.5 mm Hg to 105.3. The diastolic blood pressure was not significantly reduced, heart rate was not affected. Urapidil did not affect the responses to angiotensin or isoprenaline. Urapidil inhibited the pressor response to phenylephrine. The dose required to increase systolic blood pressure by 20 mm Hg increased from 156.9 g·min^–1 before to 685 g·min^–1 during urapidil; Dose ratio from individual values of 4.58. Urapidil concentrations were not significantly different before and after each agonist infusion. It is concluded that urapidil has ₁-adrenoceptor blocking activity in man without any non specific vasodilator action and that it is devoid of beta adrenoceptor blocking action.     

Early report: comparison of breath-hold MR excretory urography, Doppler ultrasound and isotope renography in evaluation of symptomatic hydronephrosis in pregnancy

AIM: To compare assessment by MR excretory urography (MREU), Doppler ultrasound and isotope renography of women with symptomatic hydronephrosis in pregnancy and to define its cause.MATERIALS AND METHODS: Eleven women at 19-34 weeks of gestation were studied prospectively with gadolinium-enhanced breath-hold gradient echo MREU and transabdominal Doppler ultrasound compared with a 'gold standard' of isotope renography employing frusemide challenge. All studies were performed within 24 h, were reported independently in a blinded fashion and employed clearly defined criteria. Obstetric and infant outcomes were obtained.RESULTS: There were no adverse reactions to gadolinium administration in pregnancy and no adverse obstetric or infant outcomes. Three of the 11 women were unable to tolerate the complete MREU protocol. Ultrasound indices could not be used to predict ureteric obstruction as shown by isotope renography. MREU agreed with renographic findings in five of the six cases with obstruction and in two without obstruction. MREU directly demonstrated hydronephrosis to result from extrinsic compression of the ureter between the gravid uterus and iliopsoas muscle. CONCLUSION: MR excretory urography is a promising technique which affords equivalent functional and additional anatomical information to isotope renography. It is more accurate than Doppler ultrasound in the assessment of ureteric obstruction in pregnancy.Spencer, J. A. (2000). Clinical Radiology55, 446-453.     

Refining the Amsterdam Criteria and Bethesda Guidelines: testing algorithms for the prediction of mismatch repair mutation status in the familial cancer clinic.

PURPOSE: Hereditary nonpolyposis colon cancer (HNPCC) is a Mendelian dominant syndrome of bowel, endometrial, and other cancers and results from germline mutations in mismatch repair (MMR) genes. HNPCC is now best diagnosed on molecular grounds using MMR mutation screening, aided by microsatellite instability (MSI) and immunohistochemistry in tumors. Selection of families for molecular investigation of HNPCC is usually based on suboptimal methods (Amsterdam Criteria or Bethesda Guidelines), but these can be improved using additional clinical data (mean ages of affected persons and presence of endometrial cancer) in a quantitative model. METHODS: We have verified the performance of the Wijnen model and have shown that it remains valid when HNPCC is diagnosed using mutation screening, MSI, and immunohistochemistry. We have also set up and verified our own models (Amsterdam-plus and Alternative), which perform at least as well as the Wijnen model. RESULTS: The Amsterdam-plus model improves on the Amsterdam Criteria by using five extra variables (numbers of colorectal and endometrial cancers in the family, number of patients with five or more adenomas, number with more than one primary cancer of the colorectum or endometrium, and mean age of presentation) and performs better than the Wijnen model. The Alternative model avoids the need to evaluate the Amsterdam Criteria and performs nearly as well as the other models. CONCLUSION: We believe that a quantitative model, such as the Amsterdam-plus model, should be the first choice for selecting families or patients for evaluation of HNPCC using molecular tests. We present an algorithm for this process.     

Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea

Several epidemiological studies point to a strong correlation between nutrient composition of the diet and cancer of the colon. Phytic acid, present in grains, has been credited with reducing the risk of cancer of the colon. A number of reports are available indicating the benefits of green tea consumption in reducing the risk of stomach, lung and skin cancer, but little data are available on the effect of green tea in reducing the risk of colon cancer. Also, there are no studies on the combined effect of these compounds on colon tumorigenesis. Thus the primary objective of this investigation was to elucidate the combined effects of green tea and phytic acid on colonic preneoplastic lesions and the Phase II enzyme glutathione S-transferase. Fisher 344 male weanling rats were divided into nine groups of 15 rats each and fed the experimental diet for 13 weeks. Rats received two s.c. injections of azoxymethane in saline at 16 mg/kg body wt at 7 and 8 weeks of age. Rats received three levels (0, 1 and 2%) of phytic acid with three levels (0, 1 and 2%) of green tea within each phytic acid level in a 3 x 3 factorial experiment. Results indicate that while green tea had a marginal effect (P < 0.14), phytic acid significantly reduced the incidence of aberrant crypt foci (P < 0.008). The interaction between green tea and phytic acid was significant (P < 0.029 for distal and < 0.0168 for entire colon) and positive, pointing to a synergistic effect of green tea and phytic acid.      

Exploring the decision-making preferences of people with colorectal cancer

OBJECTIVES: To explore patient views on participation in treatment, physical care and psychological care decisions and factors that facilitate and hinder patients from making decisions. DESIGN: Qualitative study using semi-structured interviews with patients. SETTING AND PARTICIPANTS: Three NHS Trusts in the north-west of England. Theoretical sampling including 41 patients who had been treated for colorectal cancer. RESULTS: For patients, participation in the decision-making process was about being informed and feeling involved in the consultation process, whether patients actually made decisions or not. The perceived availability of treatment choices (surgery, radiotherapy, chemotherapy) was related to type of treatment. Factors that impacted on whether patients wanted to make decisions included a lack of information, a lack of medical knowledge and trust in medical expertise. Patients perceived that they could have a more participatory role in decisions related to physical and psychological care. CONCLUSION: This study has implications for health professionals aiming to implement policy guidelines that promote patient participation and shared partnerships. Patients in this study wanted to be well informed and involved in the consultation process but did not necessarily want to use the information they received to make decisions. The presentation of choices and preferences for participation may be context specific and it cannot be assumed that patients who do not want to make decisions about one aspect of their care and treatment do not want to make decisions about other aspects of their care and treatment.