Effects of Losartan and Amlodipine on Left Ventricular Remodeling and Function in Young Stroke-Prone Spontaneously Hypertensive Rats.

BACKGROUND: The purpose of this study was to evaluate the effects of prehypertensive losartan and amlodipine administration on left ventricular (LV) remodeling and function in spontaneously hypertensive rats-stroke prone (SHRSP). METHODS: Spontaneously hypertensive rats-stroke prone were prehypertensively administered losartan, amlodipine, or vehicle. Wistar-Kyoto rats were used as a control. Blood pressure of the rats was determined by tail-cuff method, and LV structure and function were measured by echocardiography and LV cannulation. Collagen volume fraction was analyzed by picrosirius red staining. Protein expressions of brain natriuretic peptide (BNP) and angiotensin II type 1 (AT1R) and type 2 (AT2R) receptors were determined by use of the Western blotting method. RESULTS: Although both drugs downregulated BNP protein expression, the LV remodeling and function were more improved with losartan than with amlodipine treatment. Losartan upregulated AT1R and downregulated AT2R protein expression. CONCLUSIONS: Both drugs inhibited LV remodeling and improved LV function in prehypertensively treated SHRSP. Losartan provided better continued heart protection, potentially due to its persistent inhibition of AT1R and activation of AT2R in the myocardium. KEY WORDS: Amlodipine; Blood pressure; Heart; Losartan; Prehypertension.

[Impact of resting heart rate on new-onset diabetes in population without hypertension].

OBJECTIVE: To investigate the impact of resting heart rate (RHR) on new-onset diabetes (NOD) in population without hypertension. METHODS: This prospective cohort study was performed in 2006 and 2007 and screened 101 510 participants. All subjects were employees of the Kailuan Group, a state-run coal mining company. The observation cohort included 48 926 subjects with normal fasting blood glucose (FBG) <7.0 mmol/L, no history of diabetes, complete FBG and RHR examination data, systolic blood pressure <140 mm Hg (1 mm Hg = 0.133 kPa) , diastolic blood pressure <90 mm Hg, no history of hypertension, and no use of hypoglycemic agents or antihypertensive drugs.We excluded participants without a health examination in 2008-2009 or 2010-2011 and those with incomplete examination data. A total of 29 910 participants were included in the final analysis. The observation population was divided into four groups according to RHR data collected during 2006-2007 health examinations: quartile 1 (RHR<63 beats/min) ; quartile 2 (63 beats/min ≤ RHR<70 beats/min) ; quartile 3 (70 beats/min ≤ RHR<75 beats/min) ; quartile 4 ( RHR ≥ 75 beats/min). Kaplan-Meier analysis was used to calculate the incidence of NOD. The relationship between RHR and NOD was estimated using Cox proportional hazard analysis. RESULTS: The incidences of NOD/1000 person-years for the above quartiles of RHR were 11.22, 13.58, 13.96, and 17.55, respectively in the total observational population; the corresponding incidences were 12.17, 15.20, 16.08, 20.44, and 8.29, 9.38, 8.86, and 9.60 in men and women, respectively. Compared with quartile 1, Cox proportional hazard regression analysis showed that the other three RHR groups had an increased risk of NOD after adjusting for age, gender, systolic blood pressure, diastolic blood pressure, and other risk factors. The hazard ratio values for these groups were 1.20 (95%CI:1.04-1.40, P < 0.05), 1.25 (95%CI:1.07-1.45, P < 0.01) and 1.58 (95%CI:1.36-1.82, P < 0.01), respectively. Furthermore, after adjusted the FBG, risk of NOD was significantly higher in quartile 2 (HR = 1.21, 95%CI:1.04-1.40, P < 0.01) and quartile 4 (HR = 1.22, 95%CI:1.06-1.41, P < 0.01 compared that in quartile 1. After adjusting for the factors listed above, the influence of RHR on NOD was not significant in women (P > 0.05) , but there was still an increased risk of NOD in men compared with quartile 1 with hazard ratio values of 1.21 (95%CI:1.02-1.43, P < 0.05) , and 1.27 (95%CI:1.09-1.49, P < 0.01) for quartile 2 and quartile 4, respectively. CONCLUSION: Higher RHR is linked with higher risk of NOD in population without hypertension.

[Spiral computed tomography imaging of internal carotid artery diameter: a report of 260 cases].

OBJECTIVE: To explore the diameter of internal carotid artery by arterial phase imaging of multi-slice spiral computed tomography (CT). METHODS: A total of 260 routine brain CT scans of the examiner were performed. And the arterial phase images of carotid artery were acquired, observed and measured through a three-dimensional reconstruction workstation. On the diameters of target sections were measured on the multiplanar reconstruction (MPR) images of carotid artery. Two groups were categorized according to gender and 3 groups by age (25 - 40 yr, 41 - 60 yr and 61 - 85 yr) for statistical analysis. RESULTS: The diameter data of internal carotid artery had statistical significances among genders and 3 age groups (P < 0.05). CONCLUSION: The diameter of internal carotid artery may be evaluated by the arterial phase imaging of multi-slice spiral CT so that the reference data can be provided for clinical diagnosis.

Molecularly imprinted solid phase extraction method for simultaneous determination of seven nitroimidazoles from honey by HPLC-MS/MS.

In this work, a selective sample cleanup procedure that combined molecular imprinting technique with solid phase extraction was developed for the simultaneous extraction of the seven nitroimidazoles (NMZs) from honey samples. The molecular imprinting polymers for NMZs were prepared through bulk polymerization method using 2-methyl-5-nitroimidazole as template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross linking agent. The obtained molecular imprinting polymers showed high affinity to template molecule and was used as selective sorbent for simultaneously selective extraction of the seven NMZs from honey matrix. An off-line molecularly imprinted solid phase extraction (MISPE) method followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) for simultaneous determination of the seven NMZs from honey samples was also established. The proposed method was validated at 1.0, 2.0 and 10.0µg/kg, obtaining recoveries in the range of 79.7-110%, with repeatability and interday precision values (expressed as relative standard deviation) ≤11.4% and ≤15.2%, respectively. Limits of quantification for different NMZs were 1.0µg/kg, which were always below the minimum required performance limits established by the European Community Reference Laboratories (Commission Decision 2002/657/EC). It was demonstrated that this proposed MISPE-HPLC-MS-MS method could be applied to direct determination of NMZs from honey samples.

Long-term prehypertension treatment with losartan effectively prevents brain damage and stroke in stroke-prone spontaneously hypertensive rats.

Prehypertension has been associated with adverse cerebrovascular events and brain damage. The aims of this study were to investigate ⅰ) whether short­ and long-term treatments with losartan or amlodipine for prehypertension were able to prevent blood pressure (BP)-linked brain damage, and ⅱ) whether there is a difference in the effectiveness of treatment with losartan and amlodipine in protecting BP-linked brain damage. In the present study, prehypertensive treatment with losartan and amlodipine (6 and 16 weeks treatment with each drug) was performed on 4-week­old stroke-prone spontaneously hypertensive rats (SHRSP). The results showed that long-term (16 weeks) treatment with losartan is the most effective in lowering systolic blood pressure in the long term (up to 40 weeks follow-up). Additionally, compared with the amlodipine treatment groups, the short­ and long-term losartan treatments protected SHRSP from stroke and improved their brains structurally and functionally more effectively, with the long-term treatment having more benefits. Mechanistically, the short­ and long-term treatments with losartan reduced the activity of the local renin-angiotensin-aldosterone system (RAAS) in a time-dependent manner and more effectively than their respective counterpart amlodipine treatment group mainly by decreasing AT1R levels and increasing AT2R levels in the cerebral cortex. By contrast, the amlodipine treatment groups inhibited brain cell apoptosis more effectively as compared with the losartan treatment groups mainly through the suppression of local oxidative stress. Taken together, the results suggest that long-term losartan treatment for prehypertension effectively protects SHRSP from stroke-induced brain damage, and this protection is associated with reduced local RAAS activity than with brain cell apoptosis. Thus, the AT1R receptor blocker losartan is a good candidate drug that may be used in the clinic for long-term treatment on prehypertensive populations in order to prevent BP-linked brain damage.

[CT radiographic study of different paths of iliac screw path].

OBJECTIVE: To investigate the best effective and accepted path of iliac screws for lumbar sacral spine and pelvis to provide reference for reconstruction. METHODS: From Feb. 2009 to Aug. 2009, radiographic data of 50 patients were selected for various reasons, pelvic CT scanning and three-dimensional reconstruction and no positive performance, included 28 males and 22 females with an average age of 41.2 years old, ranging from 19 to 65 years. Designed four paths, in path A, B, C, CLIC (crossing point of Chiotic line and posterior iliac crest, located 24 mm on the top of posterior superior iliac spine) was the starting point for the path in the direction of the upper edge of the acetabulum, anterior inferior iliac spine, acetabulum center; in path D, the posterior superior iliac spine was starting point to direct anterior inferior iliac spine. The length of the screw channel and two narrow points in the screw channel of the bone plate thickness data of each different path were measured and analyzed. RESULTS: The path A (CLIC point to the upper edge of the acetabulum) and the path B (CLIC point to the AIIS) and the path D (PSIS to AIIS) had correspond length of the screw channel, but the thickness of iliac of path A was thicker than that of path B and D. The iliac thickness of path A (CLIC point to the upper edge of the acetabulum) and the path C (CLIC point to the acetabular center) has no significant difference, but the channel length of path A was significant longer than that of path C. CONCLUSION: Path A from the CLIC point to the direction of the upper edge of acetabular ilium nail route was the longest path and the iliac bone plate was the most thick, and able to accommodate the relatively longest and most coarse iliac screw, but also bear the greatest tension. It is the best iliac nail route.

Molecularly imprinted polymer as SPE sorbent for selective extraction of melamine in dairy products.

In this paper, a highly selective sample cleanup procedure combining molecular imprinting and solid-phase extraction (MI-SPE) was developed for the isolation of melamine in dairy products. The molecularly imprinted polymer (MIP) was prepared using melamine as the template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking monomer. The melamine imprinted polymer was used as selective sorbent for the solid-phase extraction of melamine from dairy products. An off-line MI-SPE method followed by high-performance liquid chromatography with diode-array detection for the detection of melamine was also established. The mean recoveries of melamine from ultra-heat treatment (UHT) milk and milk powders were 92.9-98.0% and 91.6-102.8%, respectively. Good linearity was obtained from 0.5 microM to 10 microM (r>0.999) with a quantitation limit of 0.5 micromol/L (0.06 ppm) which was sufficient to analyse melamine at the maximum level permitted by U.S. Food and Drug Administration (1 ppm) in dairy products. It was demonstrated that the proposed MI-SPE-HPLC method could be applied to direct determination of melamine in dairy products.