Influence of pupil size and other test variables on visual function assessment using visual evoked potentials in normal subjects

The purpose of this study was to assess the influence of pupil size and optical blur on measurements obtained with isolated-check visual evoked potential (icVEP). Two stimulus conditions of icVEP, +15 and −15% contrasts, were studied in normal subjects with normal (N), miotic (M), and dilated (D) pupils. The effects of optical blur were studied in subjects with normal pupil. Response to visual stimuli was quantified by a signal-to-noise (SNR) ratio. In 30 normal subjects, the mean age was 26.0 ± 3.4 years. Mean pupil diameters were N = 4.2 ± 0.6 mm, M = 2.7 ± 0.6 mm, and D = 7.3 ± 0.9 mm. For both +15 and −15% contrast levels, mean SNR values were reduced for dilated and constricted pupils when compared with normal pupils. Mean SNR values for optical blur with a +2 or +3 diopter lens placed over the distance correction were reduced when compared with SNR measurements obtained with best-corrected visual acuity under both +15 and −15% contrast levels. Statistical significance was found in comparisons of N versus M (P < 0.001) and N versus D (P = 0.002) for +15 and −15% contrast conditions, respectively. No statistical difference was seen for M versus D (P = −0.435). The effect of optical blur was statistically significant when compared to the normal pupils with best-corrected vision (P < 0.001). No statistically significant difference was found comparing +2 and +3 diopters lenses for optical blur testing. Visual evoked potential values are influenced by pupillary constriction and dilation, as well as optical blur. When obtaining icVEP measurements, the influence of pupil size and optical blur should be kept in mind for accurate interpretations.     

Likelihood ratios for fetal trisomy 21 based on nasal bone length in the second trimester: how best to define hypoplasia?

OBJECTIVE: To determine the best measure of fetal nasal bone hypoplasia for trisomy 21 risk assessment in the second trimester. METHODS: This was a prospective, observational study performed at a single institution between February 2003 and December 2005. Fetuses with nasal bone length recorded sonographically between 16 and 20.9 weeks and known karyotype were included. Definitions of nasal bone hypoplasia assessed included: non-visualized nasal bone, nasal bone < 10th percentile, nasal bone < 2.5th percentile, biparietal diameter/nasal bone ratio >or= 10 and >or= 11 and nasal bone multiples of the median (MoM) 相似文献   

Comparison of twice-daily and three-times-daily dosing of dorzolamide in ocular hypertension and primary open-angle glaucoma patients treated with latanoprost

Introduction

Clinically, dorzolamide (Trusopt®; Merck &; Co Inc, West Point, PA, USA) is often used twice daily (b.i.d.) or three times daily (t.i.d.) as adjunctive therapy with prostaglandins. Our purpose was to determine the effect of dorzolamide on intraocular pressure (IOP) when added to latanoprost (Xalatan®; Pfizer Inc, New York, NY, USA) baseline treatment, and to evaluate potential efficacy differences between b.i.d. and t.i.d. dosing of dorzolamide.

Methods

This was a prospective, randomised, two-period crossover trial in ocular hypertensive or primary open-angle glaucoma patients (29 eyes in 15 patients) with an IOP of > 20 mmHg on latanoprost baseline treatment. Patients were randomly assigned to b.i.d. (08.00 and 20.00) or t.i.d. (08.00, 16.00 and 20.00) dosing of dorzolamide, treated in both eyes for 4 weeks, washed out for 3 weeks, then switched to the opposite dosing frequency for 4 weeks. Diurnal IOP measurements (every 2 hours from 08.00 to 20.00) were performed at baseline and at the end of treatment periods.

Results

The mean baseline IOP was 20.9±0.6 mmHg. After b.i.d. and t.i.d. dosing, the mean IOP was 17.7±0.6 mmHg (13.5% reduction) and 17.8±0.8 mmHg (16.5% reduction), respectively (both P<0.001 compared with baseline IOP). Diurnal IOP control was similar in the two groups, although mean IOP reduction was significantly lower at 18.00 on the t.i.d. regimen (4.7±3.3 mmHg) than with the b.i.d. regimen (2.3±2.7 mmHg, P=0.038). At other time points, no significant differences between the groups were observed.

Conclusion

Dorzolamide 2% added to latanoprost 0.005% baseline treatment caused a significant decrease in IOP. The b.i.d. versus t.i.d. dosing of dorzolamide did not significantly affect a change in IOP except at one afternoon time point.

     

Pelvic exenteration for T4 rectal cancer: a series of 15 ressectable cases

BACKGROUND: Pelvic exenteration is the best therapeutic choice for treatment of T4 rectal cancer. Although, this operation still presents considerable mortality and high morbidity. AIM: To report on a series of 15 patients with a T4 rectal cancer at a general hospital and describe the outcomes (morbidity, mortality and long-term survival) following pelvic exenteration. METHODS: Complete follow-up data were available on 15 patients who underwent pelvic exenteration for T4 rectal cancer between 1998 and 2006. These subjects comprised seven men and eight women with a mean age of 65 years. All of them presented serious incapacitating complaints. The surgical procedures included: infraelevator exenteration (n = 6), supraelevator exenteration (n = 4), posterior exenteration (n = 3) and, posterior exenteration plus partial cystectomy and ureterectomy (n = 2). RESULTS: The mean duration of surgery was 403 minutes (280-485). The mean blood loss was 1620 mL (300-4.800). The postoperative mortality was 6,66% (n = 1). The overall rate morbidity was 53,3% (n = 8). The pathological examination showed that all resections were R0. Lymph node involvement was present in four patients (26,66 %), and all of them died due to tumor recurrence. The overall 5-year survival rate was 35,7%. CONCLUSION: In spite of its aggressive nature and high morbidity, pelvic exenteration seems justified in rectal carcinoma when the disease extends to the urinary or genital tract. This procedure may offer long-term disease control.     

HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine

The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers.     

Laparoscopic liver resection: Experience based guidelines

Laparoscopic liver resection(LLR) has been progressively developed along the past two decades. Despite initial skepticism, improved operative results made laparoscopic approach incorporated to surgical practice and operations increased in frequency and complexity. Evidence supporting LLR comes from case-series, comparative studies and meta-analysis. Despite lack of level 1 evidence, the body of literature is stronger and existing data confirms the safety, feasibility and benefits of laparoscopic approach when compared to open resection. Indications for LLR do not differ from those for open surgery. They include benign and malignant(both primary and metastatic) tumors and living donor liver harvesting. Currently, resection of lesions located on anterolateral segments and left lateral sectionectomy are performed systematically by laparoscopy in hepatobiliary specialized centers. Resection of lesions located on posterosuperior segments(1, 4a, 7, 8) and major liver resections were shown to be feasible but remain technically demanding procedures, which should be reserved to experienced surgeons. Hand-assisted and laparoscopy-assisted procedures appeared to increase the indications of minimally invasive liver surgery and are useful strategies applied to difficult and major resections. LLR proved to be safe for malignant lesions and offers some short-term advantages over open resection. Oncological results including resection margin status and long-term survival were not inferior to open resection. At present, surgical community expects high quality studies to base the already perceived better outcomes achieved by laparoscopy in major centers' practice. Continuous surgical training, as well as new technologies should augment the application of lap-aroscopic liver surgery. Future applicability of new technologies such as robot assistance and image-guided surgery is still under investigation.     

Early assessment of the efficacy of a human papillomavirus type 16 L1 virus-like particle vaccine

A post hoc analysis was performed using combined data from two Phase I tolerability/immunogenicity studies of monovalent human papillomavirus type 11 (HPV11) or HPV16 L1 virus-like particle (VLP) vaccines. The goal was to determine if the HPV16 L1 VLP vaccine protected against HPV16 infection. Vaccine or placebo was given at 0, 2 and 6 months. HPV16 infection was defined by positive polymerase chain reaction (PCR) results following vaccination. The incidence of HPV infection was observed to be 0 cases per 100 person-years at risk in the vaccine group, and 5 cases per 100 person-years at risk in the control group. These results support the institution of larger efficacy trials for HPV L1 VLP vaccines.