Effect of hypohydration on gastric emptying and intestinal absorption during exercise

Dehydration and hyperthermia may impair gastric emptying (GE) during exercise; the effect of these alterations on intestinal water flux (WF) is unknown. Thus the purpose of this study was to determine the effect of hypohydration ( approximately 2.7% body weight) on GE and WF of a water placebo (WP) during cycling exercise (85 min, 65% maximal oxygen uptake) in a cool environment (22 degrees C) and to also compare GE and WF of three carbohydrate-electrolyte solutions (CES) while the subjects were hypohydrated. GE and WF were determined simultaneously by a nasogastric tube placed in the gastric antrum and via a multilumen tube that spanned the duodenum and the first 25 cm of jejunum. Hypohydration was attained 12-16 h before experiments by low-intensity exercise in a hot (45 degrees C), humid (relative humidity 50%) environment. Seven healthy subjects (age 26.7 +/- 1.7 yr, maximal oxygen uptake 55.9 +/- 8.2 ml . kg-1 . min-1) ingested either WP or a 6% (330 mosmol), 8% (400 mosmol), or a 9% (590 mosmol) CES the morning following hypohydration. For comparison, subjects ingested WP after a euhydration protocol. Solutions ( approximately 2.0 liters total) were ingested as a large bolus (4.6 ml/kg body wt) 5 min before exercise and as small serial feedings (2.3 ml/kg body wt) every 10 min of exercise. Average GE rates were not different among conditions (P > 0.05). Mean (+/-SE) values for WF were also similar (P > 0.05) for the euhydration (15.3 +/- 1.7 ml . cm-1 . h-1) and hypohydration (18.3 +/- 2.6 ml . cm-1 . h-1) experiments. During exercise after hypohydration, water absorption was greater (P < 0.05) with ingestion of WP (18.3 +/- 2. 6) and the 6% CES (16.5 +/- 3.7), compared with the 8% CES (6.9 +/- 1.5) and the 9% CES (1.8 +/- 1.7). Mean values for final core temperature (38.6 +/- 0.1 degrees C), heart rate (152 +/- 1 beats/min), and change in plasma volume (-5.7 +/- 0.7%) were similar among experimental trials. We conclude that 1) hypohydration to approximately 3% body weight does not impair GE or fluid absorption during moderate exercise when ingesting WP, and 2) hyperosmolality (>400 mosmol) reduced WF in the proximal intestine.     

Comparative effects of felodipine ER, amlodipine and nifedipine GITS on 24 h blood pressure control and trough to peak ratios in mild to moderate ambulatory hypertension: a forced titration study

OBJECTIVE: To evaluate the 24 h antihypertensive efficacy and duration of action of felodipine extended release (ER) in comparison with two other long acting dihydropyridine calcium antagonists, amlodipine and nifedipine gastrointestinal therapeutic system (GITS), in patients with mild to moderate essential hypertension substantiated by ambulatory blood pressure (BP) monitoring. DESIGN: Randomized, forced titration, parallel group study. Clinic BP was measured at every patient's visit, and 24 h ambulatory BP was monitored at baseline and at the end of each dose-titration period. SETTING: Single centre: hypertension research unit in Quebec City, Quebec. PATIENTS: There were 89 patients enrolled into the study. Eighty-four eligible patients were randomized, and 83 completed the study and were included in the final efficacy analysis. INTERVENTIONS: Following a two-to four-week washout period (baseline), patients were randomly allocated to receive felodipine ER 5 mg, amlodipine 5 mg or nifedipine GITS 30 mg for four weeks (low dose). All study patients had their daily dose doubled to felodipine ER 10 mg, amlodipine 10 mg or nifedipine GITS 60 mg for a further four weeks (high dose). MAIN RESULTS: Significant (P < 0.001) and similar changes from baseline in clinic BP were observed in all treatment groups for low and high doses. Ambulatory BP profiles showed comparable blood pressure reductions with felodipine ER and amlodipine, and a trend towards a lesser reduction with nifedipine GITS during 24 h, daytime and night-time periods. BP loads were similarly reduced with the three treatments. Trough to peak ratios (T:Ps) were calculated from 24 h ambulatory BP curves according to two different approaches: for diastolic and systolic BP, respectively, the global approach produced T:Ps of 0.49 and 0.50 with felodipine ER 5 mg; 0.50 and 0.34 with felodipine ER 10 mg; 0.70 and 0.60 with amlodipine 5 mg; 0.88 and 0.82 with amlodipine 10 mg; 0.65 and 0.55 with nifedipine GITS 30 mg; 0.68 and 0.53 with nifedipine GITS 60 mg. T:Ps in the individual approach were 0.07 and 0.10 with felodipine ER 5 mg; 0.23 and 0.31 with felodipine ER 10 mg; 0.22 and 0.31 with amlodipine 5 mg; 0.45 and 0.58 with amlodipine 10 mg; 0.27 and 0.31 with nifedipine GITS 30 mg; and 0.24 and 0.40 with nifedipine GITS 60 mg. CONCLUSION: There was no evidence in this study of a difference among felodipine ER, amlodipine and nifedipine GITS in lowering ambulatory or clinic BP. Treatment based on ambulatory BP may be preferable to treatment guided by T:Ps because ambulatory BP is firmly established as a predictor of cardiovascular risk. Furthermore, there is no consensus on how to calculate T:Ps, and different methods of calculation may give divergent results.     

Near-infrared heavy-atom-modified fluorescent dyes for base-calling in DNA-sequencing applications using temporal discrimination

A series of near-IR fluorescent dyes were prepared which contained an intramolecular heavy atom for altering the fluorescence lifetimes to produce a set of probes appropriate for base-calling in a single-lane DNA sequencing format. The heavy-atom modification consisted of an intramolecular halogen situated on a remote section of the chromophore in order to minimize the perturbation on the lifetimes and fluorescence quantum yields. In addition, the dye series possessed an isothiocyanate functional group to allow facile attachment to sequencing primers. The unconjugated dyes showed similar absorption and emission maxima (lambda abs = 765-768 nm; lambda em = 794-798 nm) as well as fluorescence quantum yields that were invariant, within experimental error, with the heavy atom. However, the lifetimes of these dyes were found to vary with the identity of the halogen substitution (I, tau f = 947 ps; F, tau f = 843 ps, measured in methanol), with an average variation within the dye series of 35 ps. The spectroscopic properties of the free dyes and the dyes conjugated to sequencing primers on the 5'-end of the oligonucleotide were determined in a DNA-sequencing matrix (denaturing gels containing formamide). The results indicated slight differences in the fluorescence properties of the free dyes compared to those of the dye/ primer conjugates in this particular matrix. Inspection of the ground-state absorption spectra showed significant aggregation for the free dyes in this solution, but the conjugated dyes exhibited no sign of aggregation due to the highly anionic nature of the oligonucleotide. The fluorescence lifetimes of the dye/primer conjugates demonstrated lifetimes which ranged from 735 to 889 ps, with an average variation of 51 ps, an adequate difference to allow facile discrimination of these dyes in DNA-sequencing conditions. In addition, the free solution electrophoretic mobilities of the native heavy-atom-modified dyes were found to be very similar. When the dye/primer conjugates were electrophoresed in a cross-linked polyacrylamide gel electrophoresis capillary column, they comigrated, indicating that, in single-lane sequencing applications, when utilizing these dyes, no postrun corrections would be required to correct for dye-dependent mobility shifts.     

The traditional and emerging role of nuts in healthful diets

Throughout history, nuts have been a staple food providing energy, protein, essential fatty acids, vitamins, and minerals. Today, nuts are classified as part of the USDA Food Guide Pyramid's Meat/ Meat Alternate Group. Foods in this group contribute protein as well as important vitamins and minerals to the diet. Nuts are also being studied for their potential health benefits. Research suggests that there may be a connection between frequent nut consumption and a reduced incidence of coronary heart disease. Thus, tradition and promising scientific evidence combine to support the role of nuts in healthful eating.     

Induction of chitinase in response to Aspergillus infection in sorghum (Sorghum bicolor (L) Moench)

Chitinase is an antifungal protein which is induced in higher plants during infection and stress. In this paper the induction of chitinase activity in response to infection by Aspergillus parasiticus (NRRL 2999) in six sorghum (Sorghum bicolor (L) Moench) genotypes and its association with aflatoxin production were investigated. Chitinase was induced in all six genotypes (two each of red, yellow and white sorghum) when infected by A parasiticus (NRRL 2999). The induction of chitinase activity was highest in the white cultivars, followed by the yellow and red genotypes, compared with healthy grains. In the white cultivars the chitinase activity increased on the 6th and 9th days after infection and was four‐ to fivefold higher than in healthy grains. The total aflatoxin produced was lower in the red genotypes than in the yellow and white genotypes. The white genotypes showed maximum total aflatoxin production at 6 days after infection. The aflatoxins produced in the white genotypes were comparable to those in the red genotypes. There was a significant positive correlation between chitinase activity and aflatoxin production in red sorghum (r² = 0.600, p ≤ 0.001) and white sorghum (r² = 0.411, p ≤ 0.001). Maximum chitinase activity was observed on day 12 in all genotypes under healthy conditions. Copyright © 2004 Society of Chemical Industry     

The princess and the pea. An unusual complication after a laparoscopic cholecystectomy

A vena porta choledochal fistula caused by an adenocarcinoma arising from a type I choledochal cyst was detected in a 42-year-old woman. The diagnostic and therapeutic aspects of this malignancy are discussed.     

Combined effect of short stature and socioeconomic status on body mass index and weight gain during reproductive age in Brazilian women

Short stature, a marker for undernutrition early in life, has been associated with obesity in Brazilian women, but not in men. We tested the hypothesis that weight gain during the reproductive years could explain this gender difference. A national two-stage household survey of mothers with one or more children under five years of age was conducted in Brazil in 1996. The subjects were women aged 20 to 45 years (N = 2297), with last delivery seven months or more prior to the interview. The regions of the country were divided into rural, North/Northeast (urban underdeveloped) and South/Southeast/Midwest (urban developed). The dependent variables were current body mass index (BMI) measured, BMI prior to childbearing (reported), and BMI change. Socioeconomic variables included mother's years of education and family purchasing power score. A secondary analysis was restricted to primiparous women. The prevalence of current overweight and overweight prior to childbearing (BMI > or = 25 kg/m2) was higher among shorter women (<1.50 m) compared to normal stature women only in the urban developed region (P < 0.05). After adjustment for socioeconomic variables, age, parity, BMI prior to childbearing, and age at first birth, current BMI was 2.39 units higher (P = 0.008) for short stature women living in the urban developed area compared with short stature women living in the urban underdeveloped area. For both multiparous and primiparous women, BMI gain compared to the value prior to childbearing was significantly higher among short stature women living in the urban developed region (P <= 0.04). These results provide clear evidence that short stature was associated with a higher BMI and with an increased risk of weight gain/retention with pregnancy in the developed areas of Brazil, but not in the underdeveloped ones.     

Coronary artery stenosis in rats affects beta-adrenergic receptor signaling in myocytes

The rotational spectrum of (CH3OH)2 has been observed in the 8 to 24 GHz region with a pulsed-beam Fabry-Perot cavity Fourier-transform microwave spectrometer. Previously we demonstrated that each transition of the a-type R(J), Ka = 0 is split into 15 states of the 16 theoretically expected states by tunneling motions. Here we show that the K = 1 states are split into the 16 expected states through the assignment of the Ka = 1 a-type transitions and DeltaKa = 1 b-type transitions. The internal-rotation analysis of the two inequivalent methyl groups presented here was guided by the previous experimental observations and theory for multidimensional tunneling, which predicts 16 tunneling components for each R(J) transition from 25 distinct tunneling motions. The effective barrier to internal rotation for the donor methyl group of (CH3OH)2 is V3 = 183.0 cm-1, and is one-half of the value for the methanol monomer (370 cm-1), while the barrier to internal rotation of the acceptor methyl group is 120 cm-1, one-third of the methanol monomer. The structure of the methanol dimer complex is similar to that of water dimer with a hydrogen bond distance of 1.96(2) A and tilt of the acceptor methanol of 77(2)degrees from the O-H-O axis (one standard deviation uncertainty). This structure shows good agreement with the angular orientation of the methyl groups derived in the internal-rotation analysis. Copyright 1997 Academic Press. Copyright 1997Academic Press