Elimination of n-butylated hydroxytoluene methylation during fatty acid analysis by gas chromatography

An improved method for fatty acids analysis with optimum recovery of highly polyunsaturated fatty acids methyl esters in biological systems is presented. The method is based on transesterification of phospholipid and triacylglycerols to fatty acid methyl esters using a commercially available reagent, Methyl-Prep II. Without proper precautions, as much as 50% of n-butylated hydroxytoluene (BHT) added to prevent oxidation of polyunsaturated fatty acids, could be methylated during the transesterification step. Methylated BHT elutes close to 14:0 (myristic acid) and no longer functions as an antioxidant, but the modified conditions virtually eliminate the methylation of BHT. Sample extraction and methylation was completed in 30 min at room temperature. A chelator (diethylenetriamine-pentaacetic acid; DTPA) is also added to prevent peroxidation of metal catalyzed free radical chain reactions. The standard deviations of the major fatty acids from multiple human plasma samples prepared on different days were less than 5%. The recovery of arachidonic acid, 20:4, from plasma was improved using the new method, and the recovery for docosahexaenoic acid, 22:6, spiked to human plasma was found to be 99%.

Spatial interference with vertical pistol sight alignment

When competition pistol shooters aim, they perform four basic visual alignment tasks. With optimal stimuli such tasks can be performed with exquisite sensitivity. However, pistol sights and the target may not constitute the optimal stimuli, and this may impose limits on how well shooters perform. By simulating pistol sights and targets on a computer monitor, we investigated how the vernier task of aligning the top edges of the front and rear pistol sights was affected by the proximity of the target aiming mark. Alignment random error in this task, an analogous measure to vernier acuity, was unaffected by the proximity of the aiming mark; however, alignment systematic error did change significantly as the proximity of the aiming mark changed. This effect was unlikely to significantly change pistol shooting performance as shooters can adjust their sights to compensate for systematic errors. Likewise, compared to the vertical spread of shots on the pistol target, alignment random error was extremely small (only 10 s arc), which implies that other sources of variation limit pistol shooting performance.

Dual metalloprotease inhibitors. 6. Incorporation of bicyclic and substituted monocyclic azepinones as dipeptide surrogates in angiotensin-converting enzyme/neutral endopeptidase inhibitors

A series of substituted monocyclic and bicyclic azepinones were incorporated as dipeptide surrogates in mercaptoacetyl dipeptides with the desire to generate a single compound which would potently inhibit both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). Many of these compounds displayed excellent potency against both enzymes. Two of the most potent compounds, monocyclic azepinone 2n and bicyclic azepinone 3q, demonstrated a high level of activity versus ACE and NEP both in vitro and in vivo.

Effect of fluorescein on the tear stability of Hong Kong-Chinese

We used the noninvasive tear break-up time (NITBUT) technique to measure the tear stability of 24 asymptomatic Hong Kong (HK)-Chinese before and after instillation of fluorescein. One eye was used as the test eye while the fellow eye served as control. We compared the NITBUT of the test eyes pre- and postinstillation of fluorescein, and compared the NITBUT of the test eyes measured postinstillation of fluorescein with the NITBUT of the control eyes. After instillation of fluorescein, both longer and shorter NITBUT were recorded in the test eyes; similar results were observed for the control eyes (no fluorescein instilled) between the first and second measurement. The median NITBUT of the test eye pre- and postfluorescein instillation were 13.3 and 13.0 s, respectively. Fluorescein did not cause any significant change in the NITBUT of HK-Chinese and the instillation of fluorescein in one eye does not affect the NITBUT of the fellow eye. Fluorescein did not appear to affect the locations of tear break up (tear defects) observed using the NITBUT test. Tear defects are most frequent near the inferior periphery of the cornea.

Contrast and luminance as parameters defining the output of the VERIS topographical ERG

The Visual Evoked Response Imaging System (VERIS I) topographical electroretinogram system (EDI Associates, San Francisco, CA) allows measurement of the response of large numbers of retinal areas simultaneously. This paper examines ERG responses derived with the VERIS system to changes in target contrast and to local reductions in luminance. There is a linear reduction of response with reductions of target contrast. Neutral density filters were placed over part of the display, to mimic the localised reductions in response which occur in glaucoma, age-related maculopathy or diabetic retinopathy. There is a definite reduction in response seen with a 0.4 ND filter, indicating that the system should have similar sensitivity in detection of retinal lesions to the commonly used visual field analysis systems.

Clinical and laboratory findings in four patients with the non-progressive hepatic form of type IV glycogen storage disease

The classic clinical presentation for type IV glycogen storage disease (branching enzyme deficiency, GSD IV) is hepatosplenomegaly with failure to thrive occurring in the first 18 months of life, followed by progressive liver failure and death by age 5 years. Although there have been two patients without apparent liver progression previously reported, no long-term follow-up clinical data have been available. We present here the clinical spectrum of the non-progressive liver form of GSD IV in four patients, and long-term follow-up of the oldest identified patients (ages 13 and 20 years). None has developed progressive liver cirrhosis, skeletal muscle, cardiac or neurological involvement, and none has been transplanted. Branching enzyme activity was also measured in cultured skin fibroblasts from patients with the classic liver progressive, the early neonatal fatal, and the non-progressive hepatic presentations of GSD IV. The residual branching enzyme activity in the patients without progression was not distinguishable from the other forms and could not be used to predict the clinical course. Our data indicate that GSD IV does not always necessitate hepatic transplantation and that caution should be used when counselling patients regarding the prognosis of GSD IV. Patients should be carefully monitored for evidence of progression before recommending liver transplantation.

The effects of a 4-year program promoting bicycle helmet use among children in Quebec

OBJECTIVES

This study assessed the effectiveness of a 4-year program of bicycle helmet promotion that targeted elementary school children in one region of Quebec. The program revolved primarily around persuasive communication and community organization, combining standard educational activities and activities to facilitate helmet acquisition and use.

METHODS

Helmet use was compared between more than 8000 young cyclists in municipalities exposed or not exposed to the program. Factors influencing helmet use were controlled through the use of multivariate analyses.

RESULTS

Helmet use increased from 1.3% before program implementation to 33% in 1993. The program was clearly effective in most cycling circumstances and for various groups of children. However, the benefits of the program were unequally distributed; the program was one third as effective in poorer municipalities as in "average-rich" ones.

CONCLUSIONS

This community-based program that combined various types of activities appeared to be effective. New intervention models are needed to ensure an equitable distribution of benefits.

Linguistic entrapment: medico-nursing biographies as fictions

This paper argues that in their trainings health professionals are encouraged to use language naively as if it were a transparent medium of scientific communication. We contend that language use, particularly in the field of mental health care, should be studied in terms of its social functions and attention should be paid to the inevitably constructive nature of language in patients' records, in order that a 'fictional distance' opens up between patients and their records. Recent developments in literary theory and narrative analysis can be deployed as theoretical frameworks to understand this process, and we suggest that more attention to the use of language should be included in the educational programmes for health care professionals to counteract the risk of 'linguistic entrapment' or 'incarceration'.

Effective cryopreservation and long-term storage of primary human hepatocytes with recovery of viability, differentiation, and replicative potential

Despite reports of successful cryopreservation of primary human hepatocytes, existing methods do not produce sufficient recovery of viable cells to meet the needs of basic research or clinical trials of hepatocellular transplantation. We now describe a protocol for efficient cryopreservation of primary human hepatocytes using University of Wisconsin (UW) solution, fetal bovine serum, and dimethyl sulfoxide (DMSO). This method provides > 90% viability of differentiated, primary human hepatocytes 8 mo after cryopreservation as measured by trypan blue exclusion, preserves hepatocyte morphology, liver-specific gene expression (alpha 1 antitrypsin), and replication. The effectiveness of UW solution as a cryopreservative agent suggests that metabolic as well as ultrastructural factors may be important in the effective cryopreservation of primary human hepatocytes. The present method represents an effective protocol for cryopreserving differentiated primary human hepatocytes for research. This method may allow characterization and banking of human hepatocytes for clinical applications, including hepatocellular transplantation and hepatic assist devices.

Genotypic variation in coxsackievirus B5 isolates from three different outbreaks in the United States

Genomic sequences in VP1/2A and 5'-non-coding region of 10 isolates of Coxsackievirus B5 from three outbreaks were compared with published sequences of another Coxsackievirus B5, swine vesicular disease virus, Coxsackievirus B1, Coxsackievirus B3, and Coxsackievirus B4. Isolates of Coxsackievirus B5 from the same outbreak showed close relations, not exceeding 7.2% in nucleotide differences. Differences were greater between isolates from different outbreaks, varying between 8.4 and 16%. We have also shown that Coxsackie B5 viruses from an outbreak in 1967 are more similar to viruses from an outbreak in 1983 than to the viruses isolated from an intervening outbreak in 1972. The sequence comparison of Coxsackievirus B5 isolates with other Coxsackie B viruses and swine vesicular study, cDNA synthesis, polymerase chain reaction, and sequencing, are suitable for rapid Coxsackie B virus detection and identification of genotypic relations between viruses originating from different outbreaks.

Production of immunoglobulins by human sIgD+ and sIgD- human blood B lymphocytes in response to stimulation with activated T cells and agonistic antibodies; effect of IL-10, IL-2 and mode of activation of T cells

Production of IgM, IgG and IgA was induced from human blood B lymphocytes by culturing with a CD40 MoAb and IL-2 for 9 days. Replacement of IL-2 by IL-10 markedly enhanced production of all three isotypes. High levels of immunoglobulin production also occurred when activated irradiated autologous T cells replaced the CD40 MoAb, and when IL-10 replaced IL-2 in these cultures a spectacular increase in IgG production occurred. The effectiveness of the T cell stimulus depended on the mode of purification of the T cells and the nature of the stimulant used to activate them. Differences in the kinetics and level of expression of CD40L on the various T cell preparations were observed, but did not account for variations in immunoglobulin-inducing efficiency. Immunoglobulin production from sIgD+ and sIgD- B cells was investigated. IgG and IgA were found in sIgD+ cultures, indicating that some isotype switching had occurred, but the major part of the IgG and IgA secreted was from cells already committed to these isotypes. Anti-IgD or anti-IgM MoAbs enhanced the proliferation of B cells induced by anti-CD40 antibody, but immunoglobulin production was not enhanced. Factors affecting the balance of proliferation and differentiation are discussed.

Preservation of peristaltic reflex in hypertrophied ileum of guinea pig

Chronic obstruction of the guinea pig ileum leads to distension and muscular hypertrophy, but how this affects passive biomechanical and nerve-mediated contractions and clearance known as peristaltic reflex is unclear. Ileum of controls had a diameter of 3.0 +/- 1.1 mm and a circular muscle thickness of 37.2 +/- 11.2 microns; 4 wk after placement of a nonconstricting Gore-Tex band, the ileum was distended to 10.0 +/- 0.19 mm, and its muscle had hypertrophied to 195.0 +/- 61.2 microns. Hypertrophied segments exceeded controls in capacity (e.g., 5.1 +/- 1.1 vs. 1.1 +/0 0.2 ml at 6 cm), compliance, and hysteresis. Threshold volumes and pressures that triggered the reflex were 3.3 +/- 1.3 ml and 3.1 +/- 0.01 mmHg in hypertrophied vs. 0.7 +/- 0.2 ml and 1.5 +/- 0.2 mmHg in controls. The diameter increase that triggered the reflex was 1.4 +/- 0.1 mm in hypertrophied segments and 0.6 +/- 0.1 mm in controls. Hypertrophied segments generated fewer contractions of virtually double the amplitude and failed to generate a pressure differential between up- and downstream sites as controls did. Hypertrophied segments generated larger stroke volumes and cumulative clearance than controls. The ratio of antegrade to retrograde clearance was similar in hypertrophied and control segments. The length of the occluding segment in hypertrophied preparations exceeded that of controls. Control contractions indented the antimesenteric border and propagated antegrade from their site of origin; bizarre writhing movements of hypertrophied segments made their contractions difficult to monitor. Thus distension and muscular hypertrophy do not interfere with the ability of the chronically obstructed guinea pig ileum to generate a peristaltic reflex at least as readily and as powerful and as effective in clearing the lumen as controls.

The effect of benoxinate on the tear stability of Hong Kong-Chinese

We conducted a series of experiments to examine the effect of local anaesthetic instillation on tear stability measurements. All experiments were conducted with the examiner masked with respect to treatments. We measured tear break-up time (TDUT) and non-invasive tear break-up time (NITBUT) 30s after instillation of benoxinate (0.4%) in a single masked experiment and found that NITBUT was significantly increased while TBUT was unaffected. In separate experiments tear stability was assessed 5 min after instillation of benoxinate and there was no significant effect on either TBUT or NITBUT measurements. In a control experiment to examine the effect of instilling a drop of liquid into the eye, neither TBUT nor NITBUT were affected 30s after the instillation of saline. No corneal staining was observed in any of the subjects after instillation of benoxinate. The results suggest that benoxinate does not affect the stability of the precorneal tear film, and that tear stability can be assessed after the instillation of unpreserved benoxinate.

Helical CT of the liver: clinical application of an automated computer technique, SmartPrep, for obtaining images with optimal contrast enhancement

OBJECTIVES

The purpose of this study was to evaluate an automated computer technique (SmartPrep) for achieving a consistently high level of contrast enhancement in the liver with helical CT. The technique compensates for variability between patients by indicating graphically the time at which scanning should be initiated to reach a desired level of hepatic enhancement.

MATERIALS AND METHODS

One hundred nine consecutive patients undergoing helical CT of the abdomen were randomly evaluated, using either a standard 70-sec delay from the start of the injection of contrast material to scanning or a newly developed, commercially available automated technique, SmartPrep. A series of multiple low-dose scans was performed until an arbitrary threshold of hepatic enhancement (50 H) over baseline was achieved. Three regions of interest (ROIs) were imaged on a baseline scan and on contrast-enhanced scans at the upper, mid, and lower liver. Average hepatic enhancement and the standard deviation over baseline was calculated for each group at all anatomic levels. For the SmartPrep group, the range of time between scan initiation and onset of scanning was calculated.

RESULTS

The mean hepatic enhancement for the control group (n = 56) was 59.8 +/- 20.1 H, which differed significantly (p = .0002) from that for the SmartPrep group (n = 53), which was 71.6 +/- 15.2 H. Comparison of the variability between the two groups' enhancement levels was also significant (p = .02). The range of delay times for the SmartPrep group was 48-86 sec. In two additional cases, abnormal graphically displayed enhancement curves were the first indication of an improper injection.

CONCLUSION

Use of SmartPrep yields a greater and more consistent level of hepatic enhancement from patient to patient than does use of a conventional fixed delay time. The ability to scan more efficiently to achieve greater hepatic enhancement using SmartPrep has significant implications for potential contrast cost savings.

Exploring the lived experiences of psychiatric nursing students through self-reflective journals

This study explores the use of journals to identify important issues facing nursing students when learning in a psychiatric setting. During a 13-week psychiatric clinical experience, 18 third-year students kept journals describing the most significant event that occurred each week, reflecting on the impact and accompanying attitudes of that event. Throughout the clinical experience, the nursing faculty read the students' journals and provided written feedback on a bi-weekly basis. Major themes that students wrote about in their journals were identified. These included: meaningful learning, issues of the novice, relationships, control, self-reflection, and identification with clients. Keeping a journal provided the students with an opportunity to become more self-reflective in their practice. The issues identified by students in their journals may assist nurse educators to anticipate the learning needs of their students in psychiatry.

Differences in visual acuity between the eyes: determination of normal limits in a clinical population

We determined the difference in visual acuity between the right and left eyes of patients and also determined the maximal level of acuity expected in a group of visually normal individuals. Visual acuity was measured in the right and left eyes of 72 subjects aged from 16 to 67 years using Bailey-Lovie type charts. The chart was read until fewer than three letters were read on a line and acuities were based on each letter correct contributing -0.02 to the overall score. For 12 of these subjects, visual acuity was measured a further four times. Average visual acuities for right and left eyes were -0.137 and -0.126log MAR, respectively. The signed visual acuity difference was normally distributed and had a standard deviation of 0.050log MAR. The mean visual acuity difference for the 12 subjects for whom the measures were repeated was 0.033log MAR (SD of the signed visual acuity difference: 0.049log MAR). We conclude that if a patient has a difference in visual acuity between the two eyes of more than 5 letters on a Bailey-Lovie style chart, further investigation is indicated.

Ethanolamine sclerotherapy of a renal cyst

We report the effective use of 5% ethanolamine oleate to sclerose a large simple renal cyst. The comparative advantages of ethanolamine versus other sclerosants are discussed in terms of adverse effects, availability and convenience. Guidelines to optimize sclerotherapy with ethanolamine are provided.

[Clinical aspects and follow-up in dilated cardiomyopathy]

Dilative cardiomyopathy is a heterogeneous myocardial disease characterized by a depressed contractile function and ventricular dilation. The exercise intolerance of patients with dilative cardiomyopathy is partly explained by changes of metabolism and composition of skeletal muscle, whereas the physical findings result from progressive heart failure and cardiac remodeling. The clinical course of the disease is highly variable and prognostic indicators of progressive heart failure or cardiac arrhythmias are of little value in the assessment of cardiac risk in an individual patient. During recent years the mortality of patients with dilative cardiomyopathy was 5-15%, which appears to be lower than previously reported. The differences in mortality today and in previous years may be explained by a more precise and earlier diagnosis of the disease and possibly better treatment strategies. Patients with a severely depressed left ventricular function but a stable clinical course, a good hemodynamic response to therapy, and an oxygen uptake of > 12 ml/kg min can be followed without heart transplantation. It can be expected that the definition of the molecular causes of dilative cardiomyopathy will lead to a better classification of the patients and the development of more efficient treatment strategies.