26-hour Period Research Articles

Passive Wireless Pressure Sensing for Gastric Manometry.

We describe a wireless microsystem for gastrointestinal manometry that couples a microfabricated capacitive transducer to a dual-axis inductor, forming a resonant inductor-capacitor (LC) sensor within an ingestible 3D printed biocompatible capsule measuring ø 12 mm × 24 mm. An inductively coupled external telemetry unit wirelessly monitors the pressure dependent resonant frequency of the LC sensor, eliminating the need for integrated power sources within the ingested capsule. In vitro tests in saline show pressure response of −0.6 kHz/mmHg, interrogation distance up to 6 cm, and resolution up to 0.8 mmHg. In vivo functionality is validated with gastrointestinal pressure monitoring in a canine beagle over a 26-hour period.

Tobacco craving and withdrawal symptoms in psychiatric patients during a motivational enhancement intervention based on a 26-hour smoking abstinence period.

INTRODUCTIONIn psychiatric patients, tobacco withdrawal symptoms are frequently seen as a barrier to smoking cessation; however, further studies are warranted in this specific population.METHODSPatients receiving in- or out-patient mental health care participated in a motivational enhancement program including a 26-hour tobacco abstinence experience with professional support and optional nicotine replacement therapy. The study included 174 subjects, of whom 159 were evaluated 1 week before and at the end of the 26-hour abstinence period. Repeated assessments included the Minnesota Nicotine Tobacco Withdrawal Scale Revised (MNWS-R), two items of the Mood and Physical Symptoms Scale (MPSS) regarding craving, the State-Trait Anxiety Inventory (STAI-S), the Beck Depression Inventory (BDI-21), and the World Health Organization Well-Being Index (WHO-5).RESULTSMore than half the participants (52.3%) succeeded in 26-hour smoking abstinence. Craving was the most frequent MNWS-R withdrawal symptom (28.3% scored ≥3 on a 0–4 scale). Comparison of pre- and post-intervention data revealed significant improvements in 13 of 16 MNWS-R symptoms as well as craving (MPSS) and well-being, and significant decreases in anxiety and depression. Increasing MNWS-R craving scores and greater depression were both significantly associated with lower success in the 26-hour smoking abstinence period.CONCLUSIONSThe negative effects of tobacco withdrawal symptoms in psychiatric patients may be substantially overestimated. Participation in a supportive structured motivational intervention with a 26-hour smoking cessation experience was well tolerated and contributed to temporary improvements in mental state. Craving is an interesting symptom to evaluate during smoking cessation attempts.

The Impact of Tidal Phase on Hurricane Sandy's Flooding Around New York City and Long Island Sound

How do the local impacts of Hurricane Sandy's devastating storm surge differ because of the phase of the normal astronomical tide, given the spatiotemporal variability of tides around New York? In the weeks and months after Hurricane Sandy's peak surge came ashore at the time of local high tide at the southern tip of Manhattan and caused record-setting flooding along the New York and New Jersey coastline, this was one question that government officials and critical infrastructure managers were asking. For example, a simple superposition of the observed peak storm surge during Sandy on top of high tide in Western Long Island Sound comes within 29 cm (less than a foot) of the top elevation of the Stamford Hurricane barrier system which would have been overtopped by 60 cm surface waves riding over that storm tide. Here, a hydrodynamic model study of how shifts in storm surge timing could have influenced flood heights is presented. Multiple flood scenarios were evaluated with Stevens Institute of Technology's New York Harbor Observing and Prediction System model (NYHOPS) having Hurricane Sandy arriving any hour within the previous or next tidal cycle (any hour within a 26-hour period around Sandy's actual landfall). The simulated scenarios of Sandy coming between 7 and 10 hours earlier than it did were found to produce the worst coastal flooding in the Upper East River, Western and Central Long Island Sound among the evaluated cases. Flooding would have generally been worse compared to the real Sandy in Connecticut and the areas of New York City around the Upper East River between the boroughs of Queens and the Bronx, exceeding record flood heights. However, the New York Harbor region would still have seen its record flood elevation exceeded, so the storm's impact could have been more widespread. The hydrodynamic model results suggest that the still-water levels would have risen to within 75 cm of the top elevation of the Stamford storm surge barrier, 46 cm lower than the naïve superposition of astronomical tide and storm surge.

Effect of parenteral l-alanyl-l-glutamine administration on phagocytic responses of polymorphonuclear neutrophilic leukocytes in dogs undergoing high-dose methylprednisolone sodium succinate treatment

To determine whether parenteral l-alanyl-l-glutamine (Ala-Gln) administration modulated phagocytic responses of polymorphonuclear neutrophilic leukocytes (PMNs) from dogs undergoing high-dose methylprednisolone sodium succinate (MPSS) treatment. 15 healthy Beagles. Dogs were randomly assigned to 3 treatment groups (n = 5/group): 38-hour IV infusion of saline (0.9% NaCl) solution (control group), saline solution with 8.5% amino acids (2.3 g/kg/d), or saline solution with 8.5% amino acids (1.8 g/kg/d) and 20% l-alanyl-l-glutamine (Ala-Gln; 0.5 g/kg/d). High-dose MPSS treatment was initiated at the same time that IV infusions began, such that a total dose of 85 mg of MPSS/kg was administered through multiple IV injections over a 26-hour period. The infusions were maintained until 12 hours after the last MPSS injection. Blood samples collected before MPSS injections began and 2, 12, and 24 hours after injections ceased were used to evaluate PMN function. MPSS injections resulted in an increase in the total number of circulating leukocytes and increases in neutrophil and monocyte counts but did not affect lymphocyte, eosinophil, or basophil counts. Lymphocyte counts in the Ala-Gln group were higher than in the control group 12 hours after MPSS injections finished. Relative to preinfusion values, phagocytic capacity, oxidative burst activity, and filamentous actin polymerization of PMNs were suppressed in all dogs except those that received Ala-Gln. Parenteral Ala-Gln administration in dogs resulted in an increase in PMN phagocytic responses that were suppressed by high-dose MPSS treatment.

Treatment of patients with essential hypertension: amlodipine 5 mg/benazepril 20 mg compared with amlodipine 5 mg, benazepril 20 mg, and placebo

This multicenter, double-masked, randomized, parallel-group study compared the efficacy, tolerability, and safety of amlodipine 5 mg/benazepril 20 mg, amlodipine 5 mg, benazepril 20 mg, and placebo in patients with essential hypertension. After a placebo run-in period, 308 patients (all white) were randomized to treatment groups and took medication once daily for 8 weeks. Blood pressure was measured after 4 and 8 weeks of treatment in the 23- to 26-hour period after dosing. Patients wore a noninvasive blood pressure monitor for 24 hours before randomization and before the final visit. Investigators recorded adverse experiences at randomization and at study weeks 4 and 8, and obtained specimens for laboratory testing at randomization and at study week 8. Three hundred seven patients were evaluated for efficacy, and 308 for tolerability and safety. At end point (the last postrandomization measurement for each patient), the reduction in mean sitting diastolic blood pressure with the amlodipine 5 mg/benazepril 20 mg treatment was statistically significantly greater than with any comparative therapy. The results of 24-hour monitoring showed that the amlodipine/benazepril treatment, unlike monotherapy, maintained the hourly mean diastolic blood pressure at < or = 90 mm Hg. A responder rate of 87.0% was observed with amlodipine 5 mg/benazepril 20 mg versus 67.5%, 53.3%, and 15.8% with amlodipine, benazepril, and placebo, respectively. This difference between the amlodipine/benazepril treatment group and each comparative single-agent treatment group was statistically significant. Drug-related adverse events occurred in 15.6% of patients in the amlodipine/benazepril group and in 24.7%, 6.5%, and 11.7% of patients in the amlodipine, benazepril, and placebo groups, respectively. Edema occurred less often in the amlodipine/benazepril group than in the amlodipine group. Overall, once-daily therapy with amlodipine 5 mg/benazepril 20 mg provided an antihypertensive effect that was statistically and clinically superior to amlodipine 5 mg alone, benazepril 20 mg alone, and placebo, was well tolerated, and was associated with less edema than the amlodipine treatment.

Mouse Whole-embryo Culture in Serum Diluted with Waymouth Medium: A Study of Valproic Acid Teratogenicity

The culture of whole post-implantation rodent embryos has become an important tool in developmental biology and toxicology. Since the establishment of this system, rat serum has been the main culture medium used. In this study, we demonstrate that medium composed of 50% serum and 50% chemically defined medium (Waymouth 705/1) permits satisfactory development of mouse embryos over a 26-hour period. In addition, our data demonstrate that, with less than 50% serum, the frequency of malformations increases and growth and differentiation decrease with dilution in a dose-dependent way. Little information is available in the literature on the types of abnormalities induced by inadequate dilutions of serum. This study shows that a chemically defined medium, supplemented with amounts of serum that are below threshold levels, interferes mainly with the normal development of the head (neural tube, eyes and maxillary processes) and with the growth of the embryo. The second part of this work compares the teratogenicity of valproic acid (VPA) in this new medium to that in undiluted serum. We show that the effects of VPA are similar in terms of the type of alterations observed, the reduction of growth and the differentiation. However, the concentrations necessary to induce these effects in Waymouth/human serum/rat serum are half of those needed in human serum/rat serum.

Spironolactone pharmacokinetics and pharmacodynamics in patients with cirrhotic ascites

The intent of this study was to identify pharmacokinetic and pharmacodynamic characteristics for spironolactone (SP) and its metabolites (canrenone, 6 beta-hydroxy-7 alpha-thiomethylspirolactone, 7 alpha-thiomethylspirolactone) in cirrhotics under steady state conditions. Nine cirrhotics with ascites participated in the study. Serial blood samples were drawn and urine was collected over a 26-hour period. Using a reverse-phase high performance liquid chromatography (HPLC) method, all samples were analyzed for SP, canrenone, 6 beta-hydroxy-7 alpha-thiomethylspirolactone, and 7 alpha-thiomethylspirolactone concentrations. Parent compound and metabolite urinary excretion rates as well as maximal concentrations and time at which these are observed were calculated. The apparent median terminal elimination rate constants (associated half-lives) were 0.0767 h-1 (9.04 hours) for SP, 0.0055 h-1 (126 hours) for 6 beta-hydroxy-7 alpha-thiomethylspirolactone, 0.029 h-1 (23.9 hours) for 7 alpha-thiomethylspirolactone and 0.012 h-1 (57.8 hours) for canrenone. SP metabolism is impaired in cirrhosis; terminal half-lives of SP and metabolites appear to be increased when compared with values reported in the literature for normals. When assuming a linear model, clearance-effect relationship estimates are best correlated with 7 alpha-thiomethylspirolactone and canrenone. Further research is required to identify specific pharmacokinetic and pharmacodynamic parameters for SP and its metabolites in this patient population.

Blood pressure measurements during dental checkups representative of 26-hour registration

The effect of dental checkups on blood pressure was investigated. In 27 normotensive patients (13 men and 14 women) aged 22 to 64 years (mean 39.75 +/- 10.5 years), a 26-hour continuous, noninvasive blood pressure registration was carried out. Of each patient at least 175 blood pressure measurements were registered during these 26 hours, giving a total amount of 4725 blood pressure measurements. A dental checkup appointment with the family dentist was included. Blood pressure values displayed the well-known diurnal variation, but the visit to the dental surgeon was not accompanied by a rise in blood pressure. There was no significant difference between the blood pressure values during the 26-hour period and those during the checkup period. During a rest period after the dental checkup, neither the systolic nor the diastolic pressure fell to any degree in relation to the 26-hour values or the visit to the surgeon.

Saliva and serum samples were collected from eight healthy volunteers every two hours during a 26‐hour period. Melatonin concentrations were measured by radioimmunoassay after chloroform extraction using radioiodinated melatonin as a tracer. Five of the subjects had high serum melatonin levels at night (peak levels higher than 75 pg/ml); in three subjects the highest serum melatonin concentration was 20‐40 pg/ml.

Saliva and serum samples were collected from eight healthy volunteers every two hours during a 26-hour period. Melatonin concentrations were measured by radioimmunoassay after chloroform extraction using radioiodinated melatonin as a tracer. Five of the subjects had high serum melatonin levels at night (peak levels higher than 75 pg/ml); in three subjects the highest serum melatonin concentration was 20-40 pg/ml. All subjects had low levels (less than 10 pg/ml) during the day. The correlations between salivary and serum levels were calculated. The regression line y = 0.33x + 3.7 pg/ml, r = 0.95, P less than 0.001, was obtained for all detectable value pairs (n = 73). The regression and correlation coefficients were almost equal for the peak values of melatonin and during the rising and descending phases of the secretion patterns. However, no significant correlation was found between low daytime salivary and serum concentrations when calculated separately. In the five high-secretors the melatonin levels in saliva reflected reliably the changes in serum, but in the three low-secretors the correlation between salivary and serum melatonin was not significant. The proportion of melatonin found in saliva decreased with increasing serum melatonin levels. Circadian rhythm parameters were estimated by single cosinor analysis. The acrophases did not differ significantly within a subject in the concomitant measurements of serum and salivary melatonin. The measurements of salivary melatonin levels seem valid for studies on melatonin rhythms, but the melatonin concentrations measured in saliva do not always consistently reflect the absolute concentrations in blood.

Three-Dimensional Localization of DNA Synthesis in Secretory Elements of Adult Female Mouse Submandibular Gland

A system based in part on three-dimensional structural relationships is described for precisely characterizing the location of cells within secretory complexes of the adult female mouse submandibular gland. The pattern of DNA synthesis during a 90-minute pulse with 3H-thymidine was characterized based upon the above system. Seventy-eight percent of all radiolabeled nuclei were found in the intercalated duct system. One-half of these were in second-order intercalated ducts. DNA synthesis was also observed in acinar cells, granular intercalated duct cells, striated granular duct cells, and granular duct cells. Some secretory complexes contained multiple radiolabeled nuclei, with some of these nuclei in a side-by-side configuration. Approximately one-half of all secretory complexes contained radiolabeled nuclei. A second survey of the frequency of complexes containing radiolabeled nuclei was conducted following four pulses at eight-hour intervals over a 26-hour period. Only about 30% of all complexes contained radiolabeled nuclei. This reduction in the frequency of radiolabeled nuclei when compared with the single pulse suggests the possibility of individual variation. However, a more prolonged period of daily injections for nine days with 3H-thymidine resulted in all but one of the secretory complexes containing radiolabeled nuclei. This latter observation suggests that cell addition in adult submandibular glands is widespread.

Heme Catabolism in Rhesus Neonates Inhibited by Zinc Protoporphyrin

The effect of zinc (II) protoporphyrin IX (ZnPP) administration (40 mumol/kg, i.v.) on neonatal heme catabolism and the associated bilirubin production was investigated in rhesus (Macaca mulatta) neonates. Carbon monoxide excretion rates (VECO), tissue heme oxygenase activity, and plasma bilirubin concentrations were measured during a 26-hour postnatal period. In ZnPP-treated neonates (n = 4), VECO values were significantly (p = 0.002) diminished by 24% within 24 h. When compared to controls (n = 3), tissue heme oxygenase activity in ZnPP-treated neonates was greatly reduced in both liver (94% inhibition, p = 0.047) and spleen (48% inhibition, p = 0.077), but essentially unaffected in the kidney and brain. Although not statistically significant, peak (24-hour) neonatal plasma bilirubin concentrations tended to be lower (23%). These results suggest ZnPP may be efficacious in reducing heme catabolism associated with neonatal jaundice.

Reduced ability to clear ultrafilterable platinum with repeated courses of cisplatin.

Ultrafilterable plasma and urinary levels of platinum were quantitated for 24 hours after the first- and fourth-course infusion of cisplatin (CDDP) to seven patients. Four patients received 80 mg/m2 and three patients received 100 mg/m2 CDDP as a 2-hour infusion. The area under the curve (AUC) of ultrafilterable platinum, average renal clearance (CIR) of ultrafilterable platinum, and percentage of the platinum dose excreted in urine (% E) were determined for each infusion over the 26-hour period of the study. The AUC was higher in all patients after the fourth-course infusion, with a median increase of 74%. The median CLR was 494 mL/min (range, 214 to 996 mL/min) for the first course and decreased to 156 mL/min (range, 108 to 271 mL/min) for the fourth-course infusion (P less than .02). The median % E was 29.2% (range, 19.6% to 37.7%) for the first course and decreased to 19.9% (range, 12.4% to 25.9%) for the fourth-course infusion (P less than .02). There was no difference in creatinine clearance for the two infusions (median, 94 mL/min; P greater than .05). Urinary excretion of B2-microglobulin (B2-MG) and N-acetyl-B-glucosaminidase (NAG) was highly variable between patients and did not provide a useful predictor of changes in renal function. Four courses of CDDP therapy resulted in significantly reduced renal elimination of platinum in patients, probably through a reduction in the secretion of the drug in the proximal tubule of the kidney. The results suggest that increased antitumor effect and toxicity could occur in patients receiving sequential courses of cisplatin.

On near-shore surface current measurements by means of radar

A radar system is presented which allows the measurement of surface currents in a coastal area of about 50 km×50 km. The basic theoretical ideas of this system are described as well as the measuring equipment and date processing developed by Barrick, Evans and Weber [1977] from NOAA (National Oceanic and Atmospheric Administration). Radar data are available from the German Bight for a 26-hour period during MARSEN 1979 (Marine Remote Sensing Experiment in the North Sea). The data have been evaluated in terms of surface currents and compared with a record from a moored current meter, 7 metres below the surface. According to the comparison surface currents as observed by radar differ from the conventionally measured subsurface currents not more than 15 cm s−1 in speed. With regard to the current direction the agreement between both independent measurements seems to be best (within 10 degrees) when the surface-current speed exceeds 30 cm s−1. However, these comparative numbers do not take into account near-surface vertical shears. Thus, currents measured by means of radar are probably more accurate than those numbers indicate.

Circadian rhythms in neonatal rat parotid gland acinar cell and ileal crypt cell mitosis.

Mitotic activity of parotid gland acinar cells and ileal crypt cells was analyzed over the course of a 26-hour period at 8 and 15 days after birth. At 8 days there is no detectable circadian rhythm of mitosis in either tissue while at 15 days after birth there is a mitotic rhythm with an amplitude of 36.8% in ileum and 26.5% in parotid gland. Possible factors which may influence and initiate circadian rhythms are discussed.