Eye function and physiology following a 161-km foot race.

Significant visual impairment occurs in a small percentage of ultramarathon participants and is thought to be due to corneal edema. Yet, the usual effects of prolonged exercise on the eye have not been previously reported. Eight study volunteers who completed the 161-km Western States Endurance Run underwent pre-race and post-race binocular and monocular visual acuity, intraocular pressure, and corneal thickness measurements. None was symptomatic with visual impairment during the race and they demonstrated no changes from pre-race to post-race in visual acuity (p = 0.11-0.95 for right, left and combined), intraocular pressure (p = 0.11-0.43 for the both eyes) and corneal thickness (p = 0.30-0.99 for both eyes at three corneal areas). We conclude that there is no evidence that ultramarathon running has an acute effect on eye function or physiology when the runner has no symptoms or findings of visual impairment.

Effective communication enhances the patients' endoscopy experience.

BACKGROUND: Undergoing an endoscopy is a stressful experience for patients. AIMS: To audit the endoscopy pathway to improve patient satisfaction. METHODS: A prospective survey of endoscopy patients to identify system improvements that were then implemented. RESULTS: The survey was performed before (N = 71) and after (N = 60) process improvements identified by the initial survey. Information provision and staff communication skills were identified for optimisation. Patient anxiety at home was significantly reduced (median 2 vs. 1, p < 0.01). Education of endoscopy staff significantly improved the quality of information provided before and after the procedure with regard to sedation (median 4 vs. 5, p < 0.01), discomfort (median 4 vs. 5, p < 0.01), complications (28 vs. 82 %, p < 0.01), findings (89 vs. 100 %, p < 0.01) and follow-up (73 vs. 90 %, p = 0.015). Gloucester Comfort Scores during endoscopy improved (median 1 vs. 0, p < 0.01) without increasing sedation levels. Patient feelings of invasion/trauma significantly decreased. Overall 95 % of patients were satisfied. CONCLUSION: Structured information leaflets and improved staff communication skills reduce anxiety and enhance patients' experiences. They are now standard operating procedures.

Measurement of long lived radioactive impurities retained in the disposable cassettes on the Tracerlab MX system during the production of [18F]FDG.

Using a High- Purity Germanium gamma-ray spectrometer, a number of radioisotopes have been identified within Tracerlab MX radiochemistry system cassettes used to synthesise [18F]FDG. Twenty radiochemistry cassettes were measured and the average total activity of each radioisotope was determined. Using these values and decay correction, the minimum time the cassettes should be left in a decay store before the specific activity falls below 0.4B q/g, the limit for disposal alongside Clinical Waste was found to be 24 months.

Evidence of inward toroidal momentum convection in the JET tokamak.

Experiments have been carried out on the Joint European Torus tokamak to determine the diffusive and convective momentum transport. Torque, injected by neutral beams, was modulated to create a periodic perturbation in the toroidal rotation velocity. Novel transport analysis shows the magnitude and profile shape of the momentum diffusivity are similar to those of the ion heat diffusivity. A significant inward momentum pinch, up to 20 m/s, has been found. Both results are consistent with gyrokinetic simulations. This evidence is complemented in plasmas with internal transport barriers.

Review article: interstitial nephritis associated with the use of mesalazine in inflammatory bowel disease.

5-Aminosalicylic acid (5-ASA) has replaced sulphasalazine as first line therapy for mild to moderately active inflammatory bowel disease and is widely used. A number of reports have linked oral 5-ASA therapy to chronic tubulo-interstitial nephritis and this relationship is now well established. Despite increasing recognition of the potential for this serious adverse event, guidelines for monitoring renal function in patients prescribed 5-ASA preparations are not widely employed. Whilst the incidence of this adverse event in the population of patients with inflammatory bowel disease treated with mesalazine is low, the morbidity in an affected individual is high with some cases progressing to end-stage renal disease. Routine monitoring of renal function is simple and inexpensive and could prevent this outcome. Based on the available data, serum creatinine should be estimated prior to commencing treatment, monthly for the first 3 months, 3-monthly for the next 9 months, 6-monthly thereafter and annually after 5 years of treatment.

PAH extraction and estimation of plasma flow in human postischemic acute renal failure.

We determined the effect of postischemic injury to the human renal allograft on p-aminohippurate (PAH) extraction (E(PAH)) and renal blood flow. We evaluated renal function in 44 allograft recipients on two occasions: 1-3 h after reperfusion (day 0) and again on postoperative day 7. On day 0 subsets underwent intraoperative determination of renal blood flow (n = 35) by Doppler flow meter and E(PAH) (n = 25) by renal venous assay. Blood flow was also determined in another subset of 16 recipients on postoperative day 7 by phase contrast-cine-magnetic resonance imaging, and E(PAH) was computed from the simultaneous PAH clearance. Glomerular filtration rate (GFR) on day 7 was used to divide subjects into recovering (n = 23) and sustained (n = 21) acute renal failure (ARF) groups, respectively. Despite profound depression of GFR in the sustained ARF group, renal plasma flow was only slightly depressed, averaging 296 +/- 162 ml. min(-1). 1.73 m(-2) on day 0 and 202 +/- 72 ml. min(-1). 1.73 m(-2) on day 7, respectively. These values did not differ from corresponding values in the recovering ARF group: 252 +/- 133 and 280 +/- 109 ml. min(-1). 1.73 m(-2), respectively. E(PAH) was profoundly depressed on day 0, averaging 18 +/- 14 and 10 +/- 7% in recovering and sustained ARF groups, respectively, vs. 86 +/- 6% in normal controls (P < 0.001). Corresponding values on day 7 remained significantly depressed at 65 +/- 20 and 11 +/- 22%, respectively. We conclude that postischemic injury to the renal allograft results in profound impairment of E(PAH) that persists for at least 7 days, even after the onset of recovery. An ensuing reduction in urinary PAH clearance results in a gross underestimate of renal plasma flow, which is close to the normal range in the initiation, maintenance, and recovery stages of this injury.

Sodium reabsorption and distribution of Na+/K+-ATPase during postischemic injury to the renal allograft.

BACKGROUND: A loss of proximal tubule cell polarity is thought to activate tubuloglomerular feedback, thereby contributing to glomerular filtration rate depression in postischemic acute renal failure (ARF). METHODS: We used immunomicroscopy to evaluate the segmental distribution of Na+/K+-ATPase in tubules of recipients of cadaveric renal allografts. Fractional excretion (FE) of sodium and lithium was determined simultaneously. Observations were made on two occasions: one to three hours after graft reperfusion (day 0) and again on post-transplant day 7. An inulin clearance below or above 25 ml/min on day 7 was used to divide subjects into groups with sustained (N = 15) or recovering (N = 16) ARF, respectively. RESULTS: In sustained ARF, the fractional excretion of sodium (FENa) was 40 +/- 6% and 11 +/- 5%, and the fractional excretion of lithium (FELi) was 76 +/- 5% and 70 +/- 2% on days 0 and 7, respectively. Corresponding findings in recovering ARF were 28 +/- 2% and 6 +/- 2% for the FENa and 77 +/- 4% and 55 +/- 3% (P < 0.05 vs. sustained) for FELi. Na+/K+-ATPase distribution in both groups was mainly basolateral in distal straight and convoluted tubule segments and collecting ducts. However, Na+/K+-ATPase was poorly retained in the basolateral membrane of proximal convoluted and straight tubule segments in sustained and recovering ARF on both days 0 and 7. CONCLUSIONS: We conclude that loss of proximal tubule cell polarity for Na+/K+-ATPase distribution is associated with enhanced delivery of filtered Na+ to the macula densa for seven days after allograft reperfusion. Whether an ensuing activation of tubuloglomerular feedback is an important cause of glomerular filtration rate depression in this form of ARF remains to be determined.

Renal blood flow: measurement in vivo with rapid spiral MR imaging.

PURPOSE: To assess the ability of three cine phase-contrast magnetic resonance (MR) imaging techniques to measure normal human renal blood flow (RBF) in vivo. MATERIALS AND METHODS: Eighteen healthy volunteers were studied with three cine phase-contrast MR imaging techniques: breath-hold, segmented k-space, two-dimensional, Fourier transform technique (ie, time-resolved imaging with automatic data segmentation, or TRIADS); a breath-hold rapid spiral acquisition; and a non-breath-hold rapid spiral acquisition that allowed resolution of both cardiac and respiratory cycles. In each case, total arterial RBF and blood flow per unit of renal volume were calculated. For each subject, RBF was measured with a standard technique of p-aminohippuric acid (PAH)-clearance hematocrit on the same day as the MR imaging examination was performed. RESULTS: The range of agreement (2 standard deviations, or 95% confidence interval) between RBF measurements obtained with the PAH-clearance hematocrit technique and the various cine phase-contrast techniques varied from +/- 17.6% to +/- 26.5%. The best agreement was obtained with non-breath-hold rapid spiral data, by using data from the end-expiratory phase of respiration. CONCLUSION: Findings with cine phase-contrast MR imaging employing rapid spiral acquisition are in good agreement with measurements made with PAH-clearance hematocrit and give the promise of clinical measurements of RBF.

Differences in reverse transcriptase activity versus p24 antigen detection in cell culture, when comparing a homogeneous group of HIV type 1 subtype B viruses with a heterogeneous group of divergent strains.

Failure to detect infection with HIV-1 non-B subtypes in some antibody screening assays has been shown. To date, however, no studies have been published evaluating the capacity of standard tests to quantify replication of divergent HIV-1 in cell culture. Reverse transcriptase (RT) activity and p24 antigen assays are the two methods most commonly used for this purpose. A homogeneous panel of HIV-1 subtype B viruses from northern Italy and a heterogeneous panel of diverse genetic subtypes (A to F and O) from different regions of the world were cultured under identical conditions. A new nonradioactive RT assay was used as a basis for comparison to evaluate the capacity of two p24 assays to quantify viral growth in both panels. Comparison of the p24 amount/RT activity (p24/RT) ratios showed that ratios in the subtype B panel tended to be markedly higher than in the diverse subtype panel. Greatest variation was seen with one of the subtype O isolates, where up to a 400 times lower ratio was obtained compared with the average ratio for the subtype B panel. In addition, one Thai subtype B virus also gave a markedly reduced ratio. Furthermore, comparison between the two p24 assays showed different abilities to detect p24 from different HIV-1 isolates. We discuss limitations for the use of anti-HIV-1 p24 antibodies produced by immunization with subtype B p24 in p24 assays.

Outcomes study of a course in breast-cancer screening.

BACKGROUND: The Breast Cancer Screening Module is a professional training course within the Professional Education for Prevention and Early Detection (PEPED) program at the University of Texas M. D. Anderson Cancer Center. An outcomes study was done to determine the module's ability to improve screening practices crucial to breast-cancer control. METHODS: The five-day course combines 17 hours of class work with 20 hours of hands-on clinical training. Subjects were followed for one year post-training. Six outcome areas were evaluated: 1) knowledge about breast-cancer prevention; 2) clinical skills; 3) changes in routine practice; 4) numbers of patients screened, referred, and diagnosed; 5) trainee satisfaction with the course; and 6) barriers to implementing screening in routine practice. The study population was 63 subjects (all nurse professionals). RESULTS: Outcomes were positive in all six evaluation areas-significant gains in general and clinical knowledge tests (p < or = 0.05); a significant increase from 54.2% pre-training to 70.5% post-training in risk counseling (p < or = 0.05); a sustained increase in screening practices (4.3 times and 2.8 times greater at 6 and 12 months post-training, respectively); 72% rate of high course satisfaction; and barriers to improved screening practices, such as time limitations among 60.4% of subjects and 57.6% of their employers, were identified. CONCLUSIONS: This unique training enhances breast-cancer prevention and screening practices and early detection.

Measurement of levels of human immunodeficiency virus type 1 reverse transcriptase (RT) and RT activity-blocking antibody in human serum by a new standardized colorimetric assay.

Standardization and calibration of a new colorimetric assay for detection of reverse transcriptase (RT) was carried out for optimal detection of RT activity-blocking antibody (RTb-Ab) in serum. A total of 99 of 100 Swedish and 54 of 54 African human immunodeficiency virus type 1 (HIV-1) antibody-positive individuals had RTb-Ab. The one RTb-Ab-negative HIV-1 serum sample from a Swedish individual was obtained early during seroconversion. Five of 615 HIV-1-negative sera from tumor patients, pregnant women, patients undergoing routine viral diagnostics, and blood donors gave false-positive results. In addition, 3 of 126 HIV-1-negative African serum samples and 2 of 91 serum samples selected because of false reactivity in other commercially available HIV antibody assays were positive for RTb-Ab. RT activity and RTb-Ab were measured in sera from newly HIV-1-infected individuals during seroconversion. Peak RT activity was usually detected between days 8 and 13 after the onset of symptoms of primary infection. In addition, HIV-1 RTb-Ab was detected in the same recently infected individuals in most cases within 1 month and in some cases as early as 10 to 12 days after the onset of symptoms. A cross-reactivity study involving HIV-1 and HIV-2 RTb-Abs and their homologous RT showed HIV-1 RTb-Ab to be highly type specific. None of 10 serum samples from HIV-1-infected individuals showed cross-reacting RTb-Ab toward HIV-2 RT, whereas 4 of 10 serum samples from HIV-2-infected patients showed cross-reactivity toward HIV-1 RT; however, the cross-reactivity toward HIV-1 RT was 3,000 times lower than that toward its homologous RT. Future uses for the assay with reference to the recent World Health Organization proposal for other methods instead of Western blotting (immunoblotting) for confirming HIV-1 infection and for methods for the diagnosis of infection as follow-up in vaccine trials are also discussed.

Potential complications of nonsteroidal anti-inflammatory drug therapy.

Since indomethacin was first marketed, some 40 years ago, the class of nonsteroidal anti-inflammatory drugs has grown larger than any other drug class in history. At present, there are at least 25 such drugs being used in the US and abroad, both clinically and in research. Despite their widespread use, their implications to health care are just beginning to be understood. The authors review updated theories on the mechanism of action, side effects, and drug interactions of nonsteroidal anti-inflammatory drug therapy. Proposed guidelines for monitoring their use are given. A more thorough understanding of the risks-to-benefits ratio is provided in an effort to achieve maximum patient satisfaction and safety.

Modification of the total first metatarsophalangeal joint implant arthroplasty.

The Swanson Silastic HP 100 Flexible Hinge Toe Implant (Dow Corning Wright, Arlington Tennessee) displays superior tensile, elongation and tear propagation strength in comparison to other silicone implant materials. It is, however, subject to many factors which may shorten its life-span. One reason for such failure has been attributed to the irregular contour of bone ends created after metatarsophalangeal joint arthroplasty, resulting in abrasion shards and shearing fractures of the implant stems and hinge. Titanium grommets were developed to alleviate this factor. This case report demonstrates a complication subsequent to total first metatarsophalangeal joint implant arthroplasty and the effectiveness of the Swanson Flexible Hinge Toe Joint Grommet. (Dow Corning Wright, Arlington, Tennessee).