24-Hour secretory pattern of dehydroisoandrosterone and dehydroisoandrosterone sulfate.

Dehydroisoandrosterone (DHA) and cortisol were measured by radioimmunoassay and protein binding techniques respectively in plasma from blood taken at 20-min intervals over 24-h periods in 3 normal men, 2 women with Stein-Leventhal syndrome and a man with a benign adrenocortical adenoma. In all subjects but the latter, DHA and cortisol were episodic and synchronous throughout the entire day; in this patient, continuous secretion of cortisol by the tumor apparently abolished stimulation of the contralateral adrenal, and DHA production was negligible. Dehydroisoandrosterone sulfate analysis in plasma displayed a pattern which, probably because of its origin both by secretion and sulfation and its long half-life showed less synchronicity with DHA and cortisol and less fluctuation than did the free hormones.     

正常人24小时胃电图检测分析

目的研究正常人２４小时胃电变化规律。方法用动态胃电图检测仪检测３０例正常人２４小时胃电图。结果平均正常胃电频率占６７．６５％（６４．５％～９４．２％），胃动过缓占１４．１５％（１．９％－２１．２％），胃动过速占８．９６％（２．０％～２０．０％）。餐后胃电主要功率较餐前明显增加（Ｐ＝０．０１４），餐后餐前主功率比值为３．１５±２．７８。三餐对胃电频率影响相似，餐后１５分钟胃电频率稍降低（Ｐ＜０．０１），此后胃电频率恢复至餐前水平。将２４小时胃电图资料，按每６小时一段，分为４段，各段时间内胃电图检测结果相似（Ｐ＞０．０５）。结论动态２４小时胃电图监测是研究长时间胃电节律变化的有效方法。     

24-Hour QT variability in heart failure

Background

Previous studies have shown that increased temporal variability of repolarization, as reflected by QT interval variability measured for 10 minutes, predicted spontaneous ventricular arrhythmias in implantable cardioverter defribrillator patients, but it is unclear how these measures perform in 24-hour recordings.

Methods

Twenty-four-hour digital Holter recordings from 372 subjects with chronic heart failure enrolled in Gruppo Italiano per lo Studio della Sopravvivenza nell'Insufficienza Cardiaca, (GISSI) Heart Failure study were analyzed using a template-matching, semiautomatic algorithm to measure QT and heart rate time series in sequential 5-minute epochs for 24 hours. QT variability was expressed as normalized QT variance (QTVN) or as the log ratio of the QTVN over normalized heart rate variance (QT variability index, or QTVI).

Results

A pronounced diurnal variation was seen in both QTVI and QTVN. Both were lowest in the midnight to 6 am time frame and increased throughout the day, peaking at noon to 6 pm, then decreasing 6 pm to midnight. For QTVI, all 4 time points were significantly different (P < .0001). QT variability index correlated with heart rate (r = 0.38, P < .0001) and was significantly higher for those in higher New York Heart Association (NYHA) classes (r = 0.22, P = .0003). Normalized QT variance did not correlate with heart rate or NYHA but correlated negatively with serum potassium (r = −0.22, P = .0002) and manifested the greatest increase during midmorning hours.

Conclusions

Repolarization lability as reflected in QT variability has a pronounced diurnal variation and increases significantly after 6 am, the time of greatest arrhythmic risk. QT variability for 24 hours might improve risk prediction in chronic heart failure patients and should be tested in appropriate trials.     

24-Hour Survival of ACD- and CPD-Stored Red Cells

Abstract. Using an automated differential agglutination procedure, 218 red cell survival studies were performed in patients requiring therapeutic transfusion. Blood was collected in acid-citrate-dextrose (ACD) or citrate-phosphate-dextrose (CPD). Some of the blood was stored as such and some as concentrated red cells. Adverse effects of storage on both washed and nonwashed whole blood and concentrated red cells were determined by 24-hour posttransfusion survival measurements. There were no significant differences in the storage limitations of non-washed ACD- and CPD-collected whole blood, and concentrated red cells. Washing stored red cells with either buffered or nonbuffered 0.9% sodium chloride solution with or without glucose did not significantly affect 24-hour survival. However, there was a significant decrease in survival when stored red cells were washed with CPD solution or with a buffered 0.9% sodium chloride solution supplemented with calcium and magnesium.     

Estimation of 24-Hour Sodium Excretion from Spot Urine Samples

J Clin Hypertens (Greenwich). 2010;12:174–180. ^©2010 Wiley Periodicals, Inc. Despite the effects of sodium intake on blood pressure and on response to antihypertensive medication, sodium intake is rarely monitored in clinical practice. The current method, the 24-hour urine collection for sodium excretion, is cumbersome, often incorrectly performed, and not commonly ordered. Further, its results have limited meaning because of the substantial day-to-day variation in sodium intake. A spot urine test to enable convenient, inexpensive, and serial monitoring of sodium excretion would be desirable. In this study, the accuracy of predicting 24-hour sodium excretion from a spot urine sample was assessed. The urine sodium/creatinine ratio was determined from the following urine samples: an “AM sample,” submitted at the beginning of the 24-hour urine collection; a “PM sample” collected in the later afternoon/early evening before dinner, at roughly the midpoint of the collection; and a “random sample,” collected after its completion. The ratio was then corrected for 24-hour creatinine excretion. The strongest correlation between predicted and actual 24-hour sodium excretion was observed with the PM sample collected near the midpoint (r=0.86, P<.001). This sample also identified persons with sodium excretion <100 mEq/d with a sensitivity of 100% and specificity of 82%. The sodium/creatinine ratio from a spot urine sample collected in the late afternoon/early evening at roughly the midpoint of the 24-hour collection, and adjusted for 24-hour creatinine excretion, strongly correlated with 24-hour sodium excretion. Additional studies are merited to further evaluate the role of the spot urine sample in assessing sodium intake.     

Determinants of Abnormal Supine Reflux in 24-Hour pH Recordings

A previous study showed that supine gastroesophageal reflux occurs mainly in the early nighttime period and is greater if the patient retires within 2 hr of a meal. We analyzed 306 consecutive esophageal pH studies between January and July 2003. Ninety-two patients had abnormal supine reflux. The recumbent period was divided into quarters (Q1–Q4) and reflux parameters were calculated for each period. Reflux was maximal in Q1, and decreased progressively from Q1 to Q4 (P<0.001). Median time between evening meal and retiring was no different from that for 44 upright gastroesophageal reflux patients. Patients retiring within 2 hr of a meal had a higher percentage supine reflux time (P=0.012), but no increase in reflux was observed in those retiring within 3 hr. Supine reflux occurs maximally in the early nighttime period. Although not fully explained as a postprandial phenomenon, these patients should avoid going to bed within 3 hr of a meal.     

Impact of Ingested Liquids on 24-Hour Ambulatory pH Tests

A prospective investigation of the impact ofingested liquids on 24-hr pH test scores was conducted.Eighty-two patients contributed 142 samples. The liquidsused were coffee/tea (N = 35), water (N = 32), fruit juice (N = 29), cola (N = 34), and beer (N =12). The pH of cola, juice, and beer are approximately3.0. The parameters studied included: total test time,total drink time, total minutes of pH < 4.0 during drink, minutes of pH < 4.0 10 min beforedrink, and minutes of pH < 4.0 10 min followingdrink. Analysis was performed using one-way ANOVA andrepeated measures. Age of patients, total test time, and total time pH < 4.0 were notsignificantly different (P > 0.05). The total time toconsume the drink was significantly greater (P <0.05) for beer than all other liquids. The total time(7.7 ± 6.0 min) pH < 4.0 for cola wassignificantly different (P < 0.023) than beer (3.3± 3.7 min), tea/coffee (1.4 ± 6.5 min),and water (1.1 ± 2.5 min). The percentage oftotal time pH < 4.0 was not significantly different (P >0.05) among any of the liquids. The percentage of timepH < 4.0 during the drink was the highest for cola(63 ± 47%) and juice (51 ± 57%); water,coffee/tea, and beer were not significantly different (P> 0.05). Although the impact of cola and juice werethe greatest, none of these had an impact that exceeded0.5%. The lack of impact of beer appears to be due to the increased period of time it takes toconsume. We conclude that the impact of ingested fluidsis minimal and can probably be disregarded in mostpatient groups.     

Reliability of 24-Hour Oesophageal pH Monitoring Under Standardized Conditions

Background : Twenty-four-hour pH monitoring is an investigation technique that can give both false-positive and false-negative results, depending on patient factors such as diet and different activities. The aim was to study the reproducibility of 24-h oesophageal pH monitoring under as standardized conditions as possible in patients with symptoms of gastro-oesophageal reflux disease. Methods : Antimony pH electrodes were used in 22 adult patients who were investigated twice, 6 weeks apart, under identical conditions. They were hospitalized and were served a standardized diet which had been tested to contain no lower than pH 5.0. Neither coffee nor smoking was allowed. The patients had to refrain from proton-pump inhibitors for 10 days and H 2 blockers for 2 days prior to the investigation. The paired t test was used. Results : There was no significant difference in total reflux time, upright or supine reflux time, or longest reflux periods between the two test occasions. However, there were discordant results in six patients who had normal total reflux time on one test occasion but pathological results on the other. Conclusion : Since the biological variability of gastro-oesophageal reflux is not negligible from time to time, a normal 24-h oesophageal pH test should be assessed with caution.     

Ambulatory 24-Hour Pharyngeal pH Monitoring in Healthy Korean Volunteers

Pharyngeal pH monitoring is the standard diagnostic approach for laryngopharyngeal reflux (LPR). However, the normal values for Asian populations are still unknown. We evaluated the results of ambulatory 24-h pharyngeal pH monitoring in healthy volunteers to determine the normal reference values in the Korean population. Thirty healthy subjects underwent ambulatory 24-h pharyngeal pH monitoring with glass electrodes positioned 1 cm above the upper esophageal sphincter and 5 cm above the lower esophageal sphincter, based on esophageal manometry after upper gastrointestinal endoscopy. LPR occurred in about one half of the healthy volunteers without any significant association with age, gender and body mass index. Pharyngeal acid reflux occurred mainly in the upright position. At the 95th and 90th percentile, after the exclusion of mealtimes, the upper limits of normal (ULN) for pharyngeal acid exposure were 0.41% and 0.18%. The ULNs for the number of pharyngeal acid events were 12.8 and 5.0. The corresponding ULNs for the esophagus were 5.1% and 3.8% and 62.7 and 32.6. The findings of this study help establish the reference standards for LPR in Korean patients.     

Ambulatory 24-Hour Jejunal Motility in Diarrhea-Predominant Irritable Bowel Syndrome

Background: Whether small-bowel motility is abnormal in the irritable bowel syndrome (IBS) is a controversy at present. The aim of our study was to compare ambulatory long-term jejunal motility in 35 IBS patients with predominant diarrhea to normal values obtained in 50 healthy controls. Methods: Twenty-four-hour motility was recorded in the proximal jejunum with a portable datalogger and tubemounted miniature pressure sensors. Fasting motility in the waking (W) and sleeping (S) state and the motor response to a standardized evening meal of 600 kcal underwent visual and computer-aided analysis. Results: Fasting motility in patients showed migrating motor complex (MMC) cycles of normal length and composition. Uninterrupted runs of discrete clustered contractions during phase II (W) occurred in 57% of patients and 52% of controls but had a significantly longer duration in patients (33 ± 5 versus 19 ± 7 min; p < 0.005). During phase II (W) IBS patients had an increase in aborally propagated contractions (41 ± 2% versus 35 ± 2%; p < 0.01) and higher contraction amplitudes (26.3 ± 0.8 versus 23.0 ± 0.5 mm Hg; p < 0.01). Similar differences were obtained during postprandial motility (47 ± 3% versus 39 ± 3%; p < 0.01, and 25.9 ± 0.9 versus 23.8 ± 0.05 mm Hg; p < 0.02). In three patients (8.6%) disturbed aboral migration of phase III and irregular burst activity, manometric features of chronic idiopathic intestinal pseudo-obstruction, were identified. Whereas 57% of patients had an entirely normal 24-h manometry, 43% had at least one finding not present in any healthy control. Conclusion: Small-intestinal motility is frequently but not universally abnormal in diarrhea-predominant IBS. The abnormal manometric findings are heterogeneous and range from subtle quantitative changes to severe qualitative abnormalities resembling chronic idiopathic intestinal pseudo-obstruction in a small subset of patients.