Effects of the antioxidants dihydrolipoic acid (DHLA) and probucol on xenobiotic-mediated methaemoglobin formation in diabetic and non-diabetic human erythrocytes in vitro(1).

The antioxidant effects of dihydrolipoic acid (DHLA) and probucol were investigated in a human erythrocytic in-vitro model of diabetic oxidative stress, where xenobiotics were used to form methaemoglobin. 4-Aminophenol mediated haemoglobin oxidation in non-diabetic erythrocytes was not affected by the presence of either DHLA or probucol. However, with diabetic cells, there were significant increases (P<0.01) in 4-aminophenol-mediated haemoglobin oxidation in the presence of DHLA. Methaemoglobin formed by nitrite in non-diabetic and diabetic cells was not altered by either DHLA or probucol except at one time point in diabetic cells. In non-diabetic as well as diabetic cells, methaemoglobin formed by MADDS-NHOH was significantly reduced at all three time points in the presence of DHLA (P<0.0001) but unaffected by probucol. In the presence of DHLA only, methaemoglobin formed by the products of rat microsomal oxidation of both 4-aminopropiophenone and benzocaine was markedly reduced for both xenobiotics in diabetic and non-diabetic cells (P<0.0001) compared with cells incubated in the absence of DHLA. There were no significant differences between total cellular thiol levels determined between diabetic and non-diabetic erythrocytes, nor did DHLA or probucol affect resting thiol levels. MADDS-NHOH caused a significant thiol depletion in diabetic cells, which was restored in the presence of DHLA. A further study is required to determine how DHLA attenuates the potent REDOX reactions that occur during hydroxylamine-mediated methaemoglobin formation.

Comparison of blue dye visualization and glucose oxidase test strip methods for detecting pulmonary aspiration of enteral feedings in intubated adults.

STUDY OBJECTIVE: To compare the relative utility of blue dye visualization with a glucose oxidase test strip method for detecting aspiration of enteral feedings. DESIGN: Tracheally intubated adults were prospectively monitored for aspiration of enteral feedings. SETTING: Intensive care units of two community hospitals in Michigan. INTERVENTIONS: None. PATIENTS: The experimental group consisted of 15 patients receiving enteral feedings. The control group included 14 patients not enterally fed. MEASUREMENTS AND RESULTS: Blue food coloring was added to feeding formulas to obtain a visible blue color. At 8-h intervals, tracheal secretions were examined for blue discoloration, followed by measurement of glucose concentration using a calibrated glucose meter. Clinically significant aspiration was defined to require the following: (1) a bloodless positive glucose reading (> or = 20 mg/dl); (2) one or more signs of systemic inflammation; and (3) one or more signs of respiratory deterioration. Eight (53 percent) of 15 patients in the experimental group experienced at least one episode of presumptive aspiration as defined by either a bloodless positive glucose reading or visible blue discoloration of tracheal secretions. Clinically significant aspiration occurred in 5 (33 percent) of 15 patients in whom bloodless glucose readings were positive in 13 (19 percent) of 67 samples; among patients not developing this complication, glucose was found in only 3 (5 percent) of 60 samples; (p = 0.005). Inspecting tracheal secretions for blue dye usually failed to detect aspiration episodes identifiable by the glucose oxidase test strip method (relative sensitivity, 13 percent). Blue dye visualization performed no better among patients developing clinically significant aspiration (relative sensitivity, 15 percent). Patients who developed clinically significant aspiration received more of their enteral feedings in the supine position than patients without this complication (98 percent vs 21 percent; p < 0.001). CONCLUSIONS: Inspecting tracheal secretions for blue discoloration failed to detect most episodes of enteral feeding aspiration. Glucose oxidase test strip methods should replace blue dye visualization for detecting aspiration of enteral feedings in intubated adults.

Urokinase binding and receptor identification in cultured endothelial cells.

Recombinant human single-chain urokinase (rscu-PA), two-chain urokinase (tcu-PA), and diisopropyl-fluorophosphate-treated tcu-PA (DFP-tcu-PA) bound to cultured human and porcine endothelial cells in a rapid, saturable, dose-dependent and reversible manner. Analysis of specific binding results in cultured human umbilical vein endothelial cells (HUVECs) gave the following estimated values for Kd and Bmax: 0.57 +/- 0.08 nM (mean +/- S.E.) and 188,000 +/- 18,000 sites/cell for 125I-labeled rscu-PA; 0.54 +/- 0.10 nM and 132,000 +/- 23,900 sites/cells for 125I-labeled tcu-PA; 0.89 +/- 0.14 nM and 143,000 +/- 30,300 sites/cell for 125I-labeled DFP-tcu-PA, respectively. Values for Kd were similar for primary and subcultured (six passages) HUVECs, but Bmax values were lower in subcultured HUVECs. Similar Kd values were found in cultured porcine endothelial cells; however, Bmax values varied depending on the endothelial cell type. All 125I-labeled urokinase forms yielded similar cross-linked approximately 110-kDa ligand-receptor complexes with cultured HUVECs, and 125I-labeled DFP-tcu-PA bound to a single major approximately 55-kDa protein in whole-cell lysates (ligand blotting/autoradiography), suggesting the presence of a single major approximately 55-kDa urokinase receptor in cultured HUVECs. The approximately 55-kDa urokinase receptor, isolated from several separate batches of cultured HUVECs (3-5 micrograms of protein, approximately 1 x 10(9) cells), by ligand affinity chromatography, exhibited the following properties: retained biologic activity as evidenced by its ability to bind 125I-labeled rscu-PA by ligand blotting/autoradiography and formation of a cross-linked 125I-labeled approximately 110-kDa rscu-PA-receptor complex; single-chain approximately 55-kDa protein, following reduction; complete conversion to and formation of a single major deglycosylated approximately 35-kDa protein, following treatment with N-glycanase.

Long-term postoperative dysphagia in oral/pharyngeal surgery patients: subjects' perceptions vs. videofluoroscopic observations.

Dysphagia commonly results from surgical resection of various structures within the oral, pharyngeal, and esophageal areas. The type and severity of swallowing dysfunction are based largely on the number and quantity of structures removed as well as the reconstructive procedure. Short term-recovery has been addressed in many studies. However, follow-up studies of long-term functional results and continuing swallowing problems following oral/pharyngeal surgery are unavailable. In this study, perception of swallowing dysfunction was compared with actual videofluoroscopic findings in subjects at least 1 year after oral/pharyngeal surgery. The comparative results of a questionnaire developed to evaluate patients' perception of continuing swallowing difficulty and an analysis of actual videofluoroscopic tapes indicated that the degree or type of dysphagia could not be determined from patients' subjective descriptions of the swallowing problem.

Testing the validity of categories in a theoretical perspective on chronic illness.

The purpose of this study was to analyze differences in future time perspective, loneliness and perceived maternal expressiveness between adolescents who were chronically ill with cystic fibrosis and adolescents who were reportedly healthy. The sample consisted of 30 adolescents with cystic fibrosis who were matched on selected variables with 30 healthy adolescents. They responded to the Heimberg Future Time Perspective Inventory, the Revised UCLA Loneliness Scale, and the Perceived Maternal Expressiveness Scale. The three hypotheses were tested using the t-test. Since none of the hypotheses was supported, the validity of the categories was questioned. Theoretical and practical implications are addressed.

A "second look" at interviews with adolescents.

PIP: Interviews are widely used in adolescent study as data collection methods. This article argues that such interviews contain an additional order of data, located in the conversing, which can complement the content analysis and interpretation of answers to questions. This argument is based on treating interviews with adolescents as actual instances of adolescent adult interaction and is illustrated by transcribed passages from a series of interviews with young adolescents. The purpose of the study is to outline how researchers using an interview method can examine records of the talk for valuable supplementary data. The conversational analysis sketched here is, of course, only one possible way of taking this second look. In this area, it would also be a valuable resource for investigators to study how adolescents manage their research participation under a variety of data collection methods. Adequately recorded interviews contain such data, and can be inspected for the presence or clues to the very phenomena researchers may be interested in. All of this requires the understanding that 1) the primary order of empirical data is the talking and, 2) the interviews are instances of adolescent behavior.^ieng

Vocal quality, articulation and audiological characteristics of children and young adults with diagnosed allergies.

This study details vocal quality, articulation errors, and hearing disorders in 80 children and young adults with diagnosed allergies. Results indicated that almost 50% had abnormalities in vocal quality and/or articulation and 13% had reduced auditory acuity. Vocal quality disorders showed a significant relationship to bronchial asthma in association with other allergic reactions. All subjects with diminished hearing had allergic rhinitis either singly or in combination with another disorder. Findings suggest that bronchial asthma and allergic rhinitis are related to the development of vocal quality disorders and that allergic rhinitis is associated with misarticulations and diminished hearing. The presence of speech sound omissions in allergic rhinitis patients above age 8 may predict the presence or previous history of fluctuating hearing loss.

The adolescent as theorist: An interpretive view.

This article advances a way of conceptualizing the adolescent as "theorist" derived from interpretive sociology. This formulation of the adolescent as theorist is contrasted to that available within Piagetian theory. It emphasizes the practical and the occasioned nature of theoretical activity and shows it in everyday settings. Interview conversation between an adolescent and an adult is used as empirical illustration. This formulation of the adolescent as theorist is offered as a means of entry to the scientific constitution of the adolescent as a practitioner of world building who uses the same available resources and does the same sense-making work as any competent member in a culture.

Persistent hoarseness after surgical removal of vocal cord lesions.

Surgical intervention to remove vocal cord lesions usually results in normal vocal cord quality postoperatively. However, some patients exhibit persistent hoarseness after surgery, and often they are referred to a speech pathologist for vocal rehabilitation. In this study, factors were identified in the case histories, surgical management, and behavior during voice rest of patients who experienced persistent hoarseness postoperatively. Eight of ten adult subjects were interviewed and their voices were tape-recorded before and after surgery and were determined to be hoarse postoperatively. Cumulative medical history was the only significant factor that related to persistent hoarseness. Medical histories of disease or infection affecting the respiratory tract were among the specific factors that were identified. Results indicate that patients with these medical factors should be counseled about the risk of persistent hoarseness after surgery.

Smoking habits of men and women.

The smoking habits of 1501 cigarette smokers attending 28 general practitioners in five group practices in London were assessed. Prevalence of smoking, daily cigarette consumption, and the use of cigars, untipped cigarettes, and hand-rolled cigarettes were lower in the women. After controlling for consumption the proportions of men and women who smoked every day were similar. Women who smoked 20 or more a day were similar to men in their self-reported inhaling habits and use of low-nicotine cigarettes. The results suggest that women differ from men in those aspects of smoking that are determined predominantly by social factors but that their smoking habits become similar when pharmacological motivation takes over. This apparently occurs when consumption reaches about 20 cigarettes a day, when smoking almost inevitably becomes a regular event and the sex differences disappear.

The feasibility of bench tests for disposable ECG electrode adhesiveness.

The feasibility of recommending one standard bench test that adequately qualifies electrode adhesives for clinical use was examined by UBTL. Small strips, cut from whole, commercially available disposable ECG electrodes, were attached to three types of surfaces, and samples of each type of electrode were peel tested at 15 minutes, 8 hours, and 48 hours after attachment. A program was developed to average, display, and calculate peel strength parameters. Analysis of the data showed that (a) the peel strength of electrodes varied by more than a factor of 10 when measured on human skin, and by more than a factor of 3 when measured on bench test surfaces, and (b) the peel strength of the electrode adhesive strips did not correlate with intact electrode loss on ambulatory subjects. Therefore, UBTL could not recommend one bench test that would measure adhesion performance for all electrode types appropriate for inclusion in an AAMI ECG electrode standard.

Effect of general practitioners' advice against smoking.

During four weeks all 2138 cigarette smokers attending the surgeries of 28 general practitioners (GPs) in five group practices in London were allocated to one of four groups: group 1 comprised non-intervention controls; group 2 comprised questionnaire-only controls; group 3 were advised by their GP to stop smoking; and group 4 were advised to stop smoking, given a leaflet to help them, and warned that they would be followed-up. Adequate data for follow-up were obtained from 1884 patients (88%) at one month and 1567 (73%) at one year. Changes in motivation and intention to stop smoking were evident immediately after advice was given. Of the people who stopped smoking, most did so because of the advice. This was achieved by motivating more people to try to stop smoking rather than increasing the success rate among those who did try. The effect was strongest during the first month but still evident over the next three months and was enhanced by the leaflet and warning about follow-up. An additional effect over the longer term was a lower relapse rate among those who stopped, but this was not enhanced by the leaflet and warning about follow-up. The proportions who stopped smoking during the first month and were still not smoking one year later were 0.3%, 1.6%, 3.3%, and 5.1% in the four groups respectively (P <0.001).The results suggest that any GP who adopts this simple routine could expect about 25 long-term successes yearly. If all GPs in the UK participated the yield would exceed half a million ex-smokers a year. This target could not be matched by increasing the present 50 or so special withdrawal clinics to 10 000.

Non-attenders in general practice.

Non-attenders for five years or longer (77 men and 27 women; i.e. 1.9 per cent of the practice) in a general practice of 5,750 patients were identified and paired with controls in the same practice. A survey by questionnaire was carried out.The conclusions were:(1) A higher proportion of non-attenders are self-employed,(2) A lower proportion of them had retired than their attending counterparts,(3) They are spread over the whole age-range, but with a higher concentration in the ages 35 and over,(4) They are evenly spread over the social classes,(5) They seldom seek other sources of medical advice or treatment,(6) They are significantly slimmer than their fellows,(7) Their non-attendance does not, on the whole, cloak serious but remediable illness.