Diffusion-weighted magnetic resonance imaging for demonstration of cerebral infarcts

Summary Forty-one patients demonstrating clinical symptoms for cerebral infarction were investigated by magnetic resonance imaging with diffusion-weighted echo-planar imaging (DWI) and T2-weighted imaging (T2WI). In 8 patients only DWI showed the cerebral lesions clearly. One patient with positive DWI and T2WI suffered from HSV encephalitis. DWI is superior to T2WI in assessment of small cortical infarcts and cerebral infarction in patients with preexisting vascular lesions. DWI is not specific, so other causes like cerebral hematoma and encephalitis have to be considered.      

High-calcium intake abolishes hyperoxaluria and reduces urinary crystallization during a 20-fold normal oxalate load in humans

Background: The aim of the study was to test whether increasing dietary calcium intake lowers intestinal oxalate absorption and thereby prevents hyperoxaluria and urinary crystallization during a 20-fold normal oxalate load in healthy subjects. Methods: Fourteen healthy male volunteers (age 23-44 years, BMI 21.5-27.7 kg/m²) collected 24-h urines while on free choice diet as well as on two standardized diets. The latter contained 2545 kcal, 2500 ml of mineral water, 102 g of protein, 13.6 g of sodium chloride and 2220 mg of oxalate ( 20-fold content of an average diet). Subjects were studied twice while on the standardized diet, once while eating a normal amount of calcium (1211 mg/day, oxalate-rich, diet), and once while eating 3858 mg of calcium /day (calcium and oxalate-rich diet). Results: Compared with the free-choice diet (322±36 &mgr;mol/d), UOx X V increased to 780±722 &mgr;mol/d on the oxalate-rich diet (P=0.001) and fell again to 326±31 &mgr;mol/d on calcium and oxalate-rich diet (P=0.001 vs oxalate-rich diet). Urinary glycolate (a metabolic precursor of Ox) always remained below the upper limit of the normal range and did not change between different diets, indicating that changes in UOx x V reflect respective variations in intestinal absorption of Ox. UCa x V was 4.60±0.45 mmol/d on the free choice diet and 3.20±0.32 mmol/d on the oxalate-rich diet (P=0.011 vs free-choice diet); it increased to 7.28±0.74 mmol/d on the calcium- and oxalate-rich diet (P=0.001 vs free-choice and oxalate-rich diets). As indicated by the AP (CaOx) index (Tiselius), urinary supersaturation did not vary significantly between the three diets. In freshly voided morning urines (studied in 8/14 subjects) on the oxalate-rich diet, CaOx crystals or crystal aggregates of up to 80 &mgr;m diameter were found in 5/8 urines, whereas this never occurred on the free-choice diet and only once on the calcium- and oxalate-rich diet. Conclusion: Increasing calcium intake while eating Ox-rich food prevents dietary hyperoxaluria and reduces CaOx crystallization in healthy subjects. This further illustrates that dietary counseling to idiopathic calcium-stone formers should ensure sufficient calcium intake, especially during oxalate-rich meals.     

Central corneal thickness in adult Chinese. Association with ocular and general parameters. The Beijing Eye Study

Background To evaluate the distribution of central corneal thickness and its associations in the adult Chinese population. Methods The Beijing Eye Study 2006 is a population-based study including 3,251 (73.3%) subjects (aged 45+ years) out of 4,439 subjects who participated in the survey in 2001 and who returned for re-examination. Central corneal thickness (CCT) measurements were performed by slit lamp-based optical coherence tomography. Results Central corneal thickness measurement data were available for 3,100 (95.4%) subjects. Mean CCT was 556.2±33.1 μm (median: 553 μm; range: 429–688 μm). In multiple regression analysis, CCT was significantly associated with optic disc area (P = 0.043), urban region (P < 0.001; odds ratio (OR): 4.77; 95% confidence interval (CI): 2.37, 7.17), male gender (P < 0.001; OR: 5.64; 95%CI: 2.57, 8.71), and intraocular pressure measurements (P < 0.001). It was not significantly associated with body weight (P = 0.54) and body height (P = 0.66), age (P = 0.17), and refractive error (P = 0.43). Intraocular pressure (measured by pneumotonometry) increased for each μm central corneal thickness increase by 0.03 mmHg. Conclusions In the adult Chinese population, CCT was significantly associated optic disc area, urban region, and male gender. Intraocular pneumotonometric pressure measurements increased for each μm increase in central corneal thickness by 0.03 mmHg. CCT was not associated with age and refractive error. Supported by Beijing Natural Science Foundation No 7071003, Beijing, China.     

Structure of intracorneal femtosecond laser pulse effects in conical incision profiles

PURPOSE: As the applicative potential of femtosecond lasers is to be extended from LASIK-flap creation into intrastromal ablation uses, the interdependency of influencing factors has to be understood. We therefore evaluated the relationship between focus depth, energy level, spatial distribution and morphology of fs-Laser pulse effects at a given repetition rate in corneal tissue. METHODS: The experimental study included five porcine corneae obtained from slaughterhouse pigs. Using a prototype of a femtosecond laser (FEMTEC; 20/10 Perfect Vision AG, Heidelberg, Germany), a conical circular cut was performed in posterior-anterior direction through the entire corneal profile. The laser energy applied ranged from 4.0 to 8.5 muJ. Histological sections (n = 337) of a thickness of 7 mum were obtained, stained with hematoxylin/eosin, and morphometrically evaluated. RESULTS: The intrastromal femtosecond laser effects were aligned throughout the corneal stroma in a line that followed the dissection line programmed for the laser. The lesions were mostly of roughly elliptic shape with a fine dense lining at the inner wall, without evidence of a collateral damage beyond the disruption cavity. The mean maximal diameter of the intrastromal laser effects was 34.2 +/- 18.6 mum (range: 9-120 mum), and the mean maximal lesion diameter was 60.8 +/- 42.6 mum. In multivariate analysis, the lesion type (single shot cavity, partly confluent lesions, and fully confluent lesions) was significantly associated with the laser energy applied (P = 0.027) and the lesion diameter (P = 0.01). CONCLUSIONS: At higher laser energies, the intrastromal laser lesions were larger and more confluent, suggesting that, with the prototype of femtosecond laser used, a higher laser energy may lead to more confluent intrastromal laser effects. It may facilitate the complete cutting of the corneal tissue with the laser. Neither discernable debris nor stainable collateral damage were detected, suggesting a purely mechanical action of the laser.     

Intravitreal bevacizumab for myopic choroidal neovascularization.

BACKGROUND AND OBJECTIVE: To evaluate the effect of intravitreal bevacizumab on visual acuity in patients with myopic choroidal neovascularization. PATIENTS AND METHODS: The retrospective case series study included 13 patients with myopic choroidal neovascularization who received three intravitreal injections of 1.5 mg of bevacizumab. RESULTS: At 1, 3, and 6 months after the first injection, mean visual acuity improved significantly from 0.63 +/- 0.41 logarithm of the minimum angle of resolution units (LogMAR) to 0.39 +/- 0.22 (P< .001), 0.47 +/- 0.49 (P= .002), and 0.52 +/- 0.49 LogMAR (P = 0.009), respectively. The increase in visual acuity was correlated with a significant decrease in central retinal thickness (P = .003) as measured by optical coherence tomography. Mean intraocular pressure did not change significantly (P> .05) during follow-up. CONCLUSION: Intravitreal injections of bevacizumab may be a therapeutic option for exudative myopic macular degeneration.     

Multicenter phase II trial of gefitinib first-line therapy followed by chemotherapy in advanced non-small-cell lung cancer (NSCLC): SAKK protocol 19/03.

BACKGROUND: Gefitinib is active in patients with pretreated non-small-cell lung cancer (NSCLC). We evaluated the activity and toxicity of gefitinib first-line treatment in advanced NSCLC followed by chemotherapy at disease progression. PATIENTS AND METHODS: In all, 63 patients with chemotherapy-naive stage IIIB/IV NSCLC received gefitinib 250 mg/day. At disease progression, gefitinib was replaced by cisplatin 80 mg/m(2) on day 1 and gemcitabine 1250 mg/m(2) on days 1, 8 for up to six 3-week cycles. Primary end point was the disease stabilization rate (DSR) after 12 weeks of gefitinib. RESULTS: After 12 weeks of gefitinib, the DSR was 24% and the response rate (RR) was 8%. Median time to progression (TtP) was 2.5 months and median overall survival (OS) 11.5 months. Never smokers (n = 9) had a DSR of 56% and a median OS of 20.2 months; patients with epidermal growth factor receptor (EGFR) mutation (n = 4) had a DSR of 75% and the median OS was not reached after the follow-up of 21.6 months. In all, 41 patients received chemotherapy with an overall RR of 34%, DSR of 71% and median TtP of 6.7 months. CONCLUSIONS: First-line gefitinib monotherapy led to a DSR of 24% at 12 weeks in an unselected patients population. Never smokers and patients with EGFR mutations tend to have a better outcome; hence, further trials in selected patients are warranted.     

Infrared spectroscopic examination of aqueous humor.

OBJECTIVE: The aim of this study was to report on a new technique for examining aqueous humor. PARTICIPANTS: Aqueous humor samples obtained from 198 patients (cataract: n=66 eyes; age-related macular degeneration [AMD]: n=66; diabetic macular edema: n=66) were in vitro examined by mid infrared spectroscopy. After training and validating the technique, 66 samples were taken for the final independent prediction. RESULTS: In computerized analysis of the spectrometric data, 22 (100%) cataract eyes were diagnosed as the cataract group, 17 (77%) diabetic macular edema eyes were diagnosed as the diabetic macular edema group, and 14 (64%) eyes with AMD were diagnosed as the AMD group. Mid infrared spectrometry could statistically significantly (P=0.004) differentiate between the 3 study groups. CONCLUSIONS: Mid infrared spectroscopic examination of aqueous humor may be able to differentiate eyes with cataract, AMD, or diabetic macular edema.