The Potential Use of Near Infrared Spectroscopy (NIRS) to Determine the Heavy Metals and the Percentage of Blends in Tea.

The following study analyzed the potential of Near Infrared Spectroscopy (NIRS) to predict the metal composition (Al, Pb, As, Hg and Cu) of tea and for establishing discriminant models for pure teas (green, red, and black) and their different blends. A total of 322 samples of pure black, red, and green teas and binary blends were analyzed. The results showed that pure red teas had the highest content of As and Pb, green teas were the only ones containing Hg, and black teas showed higher levels of Cu.

[Relation between changes in retinal microcirculation and other organ damage in hypertension and regression with antihypertensive treatment].

Background And Objective: The possibility to aplicate a semi-automatic computerized system to evaluate the calibre of retinal blood vessels, has shown very good reproducibility, and have let us measure the calibres of retinal arterioles and veins, and their ratio (AVR).

Patients And Method: We have measured the calibres of retinal vessels in a group of 51 hypertensive outpatients before and after 6 months' treatment with losartan or, losartan plus hydrochlorothiazide if the association was required to adequate control of the blood pressure.

Results: AVR increased from 0.

Regression of alterations in retinal microcirculation following treatment for arterial hypertension.

Evaluation of early hypertension-related alterations in retinal microcirculation has been subjective and poorly reproducible. The authors recently described a semiautomatic computerized system for evaluation of the calibre of retinal blood vessels that has shown very good reproducibility. In the study, this system was used to measure the calibres of retinal arterioles and veins, and their ratio, in a group of 51 hypertensive outpatients before and after 6 months of treatment with losartan or, if required for satisfactory blood pressure control, losartan plus hydrochlorothiazide.

Computerized measurement of retinal blood vessel calibre: description, validation and use to determine the influence of ageing and hypertension.

Objective: To validate a computer-based method for measuring the calibre of retinal blood vessels, and use it to determine the effects of ageing and arterial hypertension on the calibres of these vessels and on their ratio.

Methods: Digital eye fundus images covering a 50 degrees field and centred on the optic disc were obtained using a 540 nm filter. The boundaries of blood vessels crossing a series of circles concentric with the optic disc were located by an image analysis program; the calibres of vessels crossing the circles perpendicularly were determined automatically, the average arteriole and average vein calibres were calculated, and the arteriovenous ratio (AVR) was calculated as the ratio of these averages.