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PubMed1995

The effect of four levels of ascorbic acid and two levels of calcium on eggshell quality of forced-molted White Leghorn hens.

The present experiment evaluated the effect of four levels of ascorbic acid (0, 100, 250, and 500 ppm) and two levels of calcium (3.0 and 3.5%) on the productivity and eggshell quality of molted Single Comb White Leghorn hens, housed four per 30.5 cm wide x 45.7 cm deep cage. The 4 x 2 factorial treatment combinations were randomly assigned to eight blocks of cages. Egg production increased (P < .06) an average of 5% for the levels of 250 and 500 ppm ascorbic acid. No differences were observed for feed consumption, egg weight, and shell thickness for the different levels of ascorbic acid or calcium in the diet. An increase (P < .01) was observed for specific gravity, as the levels of ascorbic acid increased. Increasing the level of calcium from 3.0 to 3.5% increased (P < .01) specific gravity from 1.073 to 1.075. Shell weight increased (P < .01) with the higher levels of ascorbic acid (250 and 500 ppm). No interactions were observed between the levels of ascorbic acid and calcium. Results suggest that supplementing ascorbic acid to molted laying hens can be beneficial to egg production and eggshell quality.

Animal Feed↗
PubMed1990

Polyuria and polydipsia. Problems associated with patient evaluation.

Primary disorders of water balance (central diabetes insipidus, congenital nephrogenic diabetes insipidus, and psychogenic polydipsia) should always be considered in the differential diagnosis of polyuria and polydipsia. In general, animals with these disorders have only one laboratory abnormality, a low urine specific gravity. The more common causes of polyuria and polydipsia (eg, hypercalcemia, chronic renal insufficiency, pyelonephritis, hyperadrenocorticism), in most instances, have specific and obvious abnormalities associated with the complete blood count (CBC), serum chemistry profile, and urinalysis. However, in some cases, a low urine specific gravity may initially be the only abnormality in these more common ruleouts. The workup for polyuria and polydipsia, especially in those cases with normal or near normal blood work, can be tedious, time consuming, confusing, and not without significant patient morbidity. This chapter will focus on the problems associated with diagnostic testing used to evaluate animals with disorders of water balance.

Animals↗
PubMedDate not supplied

Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke.

Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p less than .01) and spin-spin (T2) relaxation time (r = .91, p less than .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.

Animals↗
PubMed2006

A typology of oral hydration problems exhibited by frail nursing home residents.

Dehydration remains a substantial problem for nursing home residents, often with poor health outcomes. The purpose of this investigation was to establish 6-month prevalence of dehydration events in nursing home residents and to describe common hydration problems of nursing home residents. In this prospective observational study, 35 nursing home residents were followed for 6 months to assess problems with hydration and to evaluate the presence of dehydration. Urine specific gravity and color, bioimpedance measurements, meal intake recordings, and chart abstraction were used to assess hydration status. Field notes and informal staff interviews were used to describe specific hydration problems and clinically relevant interventions. Dehydration events occurred in 31% (11 of 35) of residents during the 6-month period. A typology of hydration problems was developed from the field observations. The typology consists of four groups (i.e., Can Drink, Can't Drink, Won't Drink, End of Life) and six corresponding subgroups. Demographic and hydration characteristics of the subgroups were compared and contrasted. Comparisons revealed the Won't Drink group is most vulnerable to dehydration events because this group has the highest percentage of dehydration events (58%, 4 of 7), the highest average specific gravity, and the lowest consumption of fluids during meals. Nursing interventions for the subgroups are discussed. Targeting nursing interventions to the specific hydration problem exhibited is proposed.

Activities of Daily Living↗
PubMed1986

Quantitative relation of urinary phenol levels to breathzone benzene concentrations: a factory survey.

Urine samples were collected from 64 men and 88 women in shoe factories and printing plants at the end of a seven hour day shift in the latter half of a week in spring. Urine samples were also taken from 43 men and 88 women in the same factories but who were not exposed to solvents. Exposure to benzene during the shift was monitored by passive dosimeters. Both phenol in urine and benzene in activated carbon were analysed with FID gas chromatographs. The urinary concentrations of phenol were linearly related to the time weighted average concentrations of benzene in the breathzone air; the variation was so small that those exposed to 10 ppm benzene could be separated from the non-exposed at least on a group basis when the phenol concentration was corrected either for creatinine concentration or for specific gravity. The urinary phenol concentrations corresponding to 10 ppm benzene were 47.5 mg/l (as observed), 57.9 mg/g creatinine, or 46.6 mg/l (specific gravity 1.016).

Adult↗
PubMed1992

NBQX, an AMPA antagonist, reduces glutamate-mediated brain edema.

Glutamate (2.5 mg) was administered after the blood-brain barrier had been opened by a unilateral intracarotid infusion of 5 mg protamine sulfate in rats. Whereas the brain specific gravity, measured 24 h later, did not differ between the injected and non-injected side after protamine alone, glutamate significantly reduced the specific gravity in the right hemisphere indicating brain edema (P less than 0.01). NBQX, a potent AMPA receptor antagonist, significantly reduced the edema (P less than 0.01) and completely inhibited the glutamate mediated increase in albumin content in cerebrospinal fluid (P less than 0.01).

Animals↗
PubMed1988

Interactions between B lymphocyte subpopulations. Augmentation of the responses of resting B lymphocytes by activated B lymphocytes.

Mouse B lymphocytes were fractionated from normal T lymphocyte-depleted spleen cell populations using discontinuous percoll gradients and were stimulated with rabbit F(ab')2 anti-mouse mu-specific antibodies (anti-mu) plus the supernatant of Con A-stimulated rat spleen cells (SN) as a source of lymphokines. The responses of small (mean volume 120 mu 3), dense (greater than 1.087 specific gravity), resting (least spontaneous thymidine incorporation) B lymphocytes were augmented by irradiated (4000 rad), larger (mean volume greater than 170 mu 3), less dense (less than 1.081 specific gravity), activated (greater spontaneous thymidine incorporation) B lymphocytes. Proliferation was augmented 2- to 4-fold and polyclonal antibody-forming cell responses three- to sixfold. Maximal augmentation of the responses of 5 X 10(4) resting B cells was obtained with 10(4) activated B cells. Augmenting activity was specific for activated B lymphocytes in that responses were not augmented by irradiated thymocytes, T lymphoblasts, macrophages, or additional supernatant. B lymphocytes activated in vitro by LPS or anti-mu also had augmenting activity. Augmentation of responses was maximal only when activated B lymphocytes were added simultaneously with anti-mu. The interaction between activated and resting B lymphocytes did not appear to be genetically restricted. Interestingly, the augmenting activity of activated B cells could be reconstituted by a combination of supernatant and cell membranes from these cells but not by either alone, suggesting that two components are required, one soluble and the other membrane-bound. Thus, a functional interaction has been demonstrated between B lymphocyte subpopulations which differ in their state of activation, and this interaction appears to involve a novel mechanism of action.

Adjuvants, Immunologic↗
PubMedDate not supplied

The influence of religious fasting on basal tear secretion and tear break-up time.

Muslims abstain from food and drink from dawn to sunset during the holy month of Ramadan. An extended strict fasting may influence tear secretion and quality. We investigated changes in basal tear secretion (BTS) and tear break-up time (BUT) at the beginning and at the end of fasting on 32 healthy male patients with a mean age of 22.3 +/- 2.9 years. Body weight and urine specific gravity were also determined to assess the extent of dehydration due to fasting. Each case lost 0.1-1.25 kg of body weight while urine specific gravity changes were statistically insignificant. Mean BTS amount was 19.9 +/- 10.9 mm at the initial examination and 19.7 +/- 11.5 mm at the end of fasting (p = 0.9). BUT values were 20.1 +/- 9.3 sec at the beginning of fasting and 23.5 +/- 14.9 sec at the end of fasting (p = 0.19). We found that religious fasting in the winter season does not seem to affect BTS and BUT values in healthy individuals.

Adult↗
PubMed1998

Phenylephrine-induced hypertension does not improve outcome after closed head trauma in rats.

UNLABELLED: Phenylephrine-induced hypertension (increase of 30-35 mm Hg for 15 min) is reported to increase cerebral perfusion pressure and collateral flow to ischemic areas of the brain in a rat model of focal cerebral ischemia. In the present study, we examined whether phenylephrine-induced hypertension of similar magnitude and duration was beneficial in a rat model of closed head trauma (CHT). Forty-eight rats were randomized into four experimental conditions: CHT at time 0 min (yes/no), plus phenylephrine-induced hypertension (increase of 30-35 mm Hg for 15 min) at 65 min (yes/no). CHT was delivered using a weight-drop device (0.5 J). Outcome measures were neurological severity score (NSS) at 1, 4, and 24 h, and brain tissue specific gravity (microgravimetry) and injury volume (2,3,5-triphenyltetrazoium chloride) at 24 h. After CHT, NSS at 24 h (median +/- range) and brain tissue specific gravity (mean +/- SD, injured hemisphere) were 7+/-2 and 1.033+/-0.007 without phenylephrine and 8+/-2 and 1.035+/-0.005 with phenylephrine (P = 0.43), respectively. Tissue injury volume (mean +/- SD) was 335+/-92 mm3 without phenylephrine and 357+/-154 mm3 with phenylephrine (P > 0.62). The results of our study indicate that postinjury treatment with 15 min of phenylephrine-induced hypertension does not attenuate brain edema, reduce tissue injury volume, or improve neurological outcome after CHT in rats. IMPLICATIONS: Phenylephrine-induced hypertension is reported to increase cerebral perfusion pressure and blood flow in a rat model of focal cerebral ischemia. In our study, phenylephrine-induced hypertension did not decrease brain edema or tissue injury volume or improve neurological outcome in a rat model of closed head trauma.

Animals↗
PubMed1964

URINE OSMOLALITY IN A POPULATION STUDY OF HYPERTENSION.

High blood pressure occurs in the majority of cases of chronic kidney disease, while renal damage is common in the more advanced cases of essential hypertension. In a population study of hypertensive disease, therefore, it is important to provide information on renal function. Determination of plasma creatinine concentration fails as a screening test since a normal or nearly normal plasma creatinine value does not necessarily exclude severe reduction of filtration ability. The specific gravity is the most widely used index of the concentration power of the kidneys. The disadvantage of this method is that considerable variation of specific gravity may occur in urines of like osmolality. In a sample of 855 50-year-old men selected at random, the authors of this article have correlated the lowered osmolality of an early morning urine specimen with hypertension. Renal involvement and/or altered rhythm of water and solute excretion can be the cause of lowered osmolality. The determination of the concentration of early morning urine samples has a legitimate place in population studies of cardiovascular diseases. A method of determining urine osmolality is described that requires relatively simple equipment and gives results with a small standard error.

Cardiovascular Diseases↗
PubMed1998

The influence of carbohydrate-based fat replacers with and without emulsifiers on the quality characteristics of lowfat cake.

Physical and sensory characteristics of cakes prepared with either the carbohydrate-based fat replacers N-Flate, Paselli MD 10 and Litesse (0, 25, 50 and 75% of fat weight) or fat replacers plus emulsifier (mono- and diglycerides; 0 and 3% of flour weight) were studied. Specific gravity of the batter was significantly (p < or = 0.05) improved by using the carbohydrate-based fat replacers, especially at the 25 and 50% replacement levels. The combination of the emulsifier with either Paselli MD 10 or Litesse also enhanced the specific gravity. Cakes prepared with fat replacers at the 25 and 50% levels had higher volumes, specific volume and standing heights than those of the control. Cakes prepared with fat replacers at the 25, 50 and 75% levels were more compressible than the control. Cakes prepared with Paselli MD 10 had the highest volumes, specific volume, standing heights and compressibilities. Incorporation of emulsifier with fat replacers improved cake volumes, standing heights and compressibilities. Cakes prepared with fat replacers exhibited higher crust and crumb color values compared to the control. Cakes prepared with 25 or 50% fat replacers had higher mean scores for flavor, softness and eating quality than the control. Incorporation of emulsifier with fat replacers did not affect the crust color, crumb color and flavor, but significantly (p < or = 0.05) improved softness and eating quality.

Carbohydrates↗
PubMed2001

Experience with urine drug testing by the Correctional Service of Canada.

The Correctional Service of Canada implemented a urine drug-screening program over 10 years ago. The objective of this report is to describe the program and drug test results in this program for 1999. Offenders in Canadian federal correctional institutions and those living in the community on conditional release were subject to urine drug testing. Urine specimens were collected at correctional facilities and shipped by courier to MAXXAM Analytics Inc. laboratory. All urine specimens were analyzed for amphetamines, cannabinoids, cocaine metabolite (benzoylecgonine), opiates, phencyclidine, benzodiazepines, methyl phenidate, meperidine, pentazocine and fluoxetine by immunoassay screening (homogeneous EIA and ELISA assays) followed by GC-MS confirmation. Ethyl alcohol was analyzed when specifically requested. Alternative screening and confirmation methods with lower cut-off values were used, whenever urine specimens were dilute (creatinine <20mg/dl and specific gravity <or=1.003). The number of urine specimens analyzed was 44,722 in 1999 and 6.2% of these specimens were dilute based on creatinine and specific gravity analysis. The positive rate for one or more drugs was 25.5% in 1999. The highest drug positive rates were for cannabinoids (10.7%), morphine (3.2%), cocaine metabolite (3.2%), codeine (2.6%), oxazepam (2.1%), temazepam (1.1%) and ethyl alcohol (1.0%). In correctional institutions (8606 non-dilute specimens analyzed in 1999), 16.4% were positive for cannabinoids, 4.9% positive for codeine and/or morphine and 2.7% positive for oxazepam and/or temazepam. In the 537 dilute specimens collected in institutions, 21% were positive for cannabinoids, 1.3% positive for codeine and/or morphine and 1.3% positive for oxazepam and/or temazepam. In the community setting, 33,928 non-dilute specimens were collected in 1999 (9.0% were positive for cannabinoids and 3.5% positive for cocaine metabolite). In the 1651 dilute specimens collected from offenders in the community in 1999, 12.6% were positive for cannabinoids and 9.5% positive for cocaine metabolite. We conclude that forensic urine drug testing provides an objective measure of drug use by offenders in Canadian federal institutions and those offenders living in the community on conditional release.

Canada↗
PubMed1984

Endoplasmic reticulum as a site of phenylpropanoid and flavonoid metabolism in hippeastrum.

The nature of bound forms of enzymes of phenylpropanoid and flavonoid metabolism have been investigated in Hippeastrum CV Dutch Red Hybrid. Particulate components of petal homogenates were fractionated on sucrose gradients and the EDTA shift method was employed to characterize membranes of the endoplasmic reticulum. In magnesiumcontaining gradients, a portion of phenylalanine ammonia lyase, chalcone synthase, glucosyl transferase, and all of the trans-cinnamate 4-monooxygenase and NADH Cytochrome c reductase (the last an endoplasmic reticulum marker) were associated with membranes equilibrating at 1.18 specific gravity. In gradients lacking magnesium and containing EDTA, the above activities-except chalcone synthase, which was lost-and protein were diminished at 1.18 specific gravity and enhanced at lower densities characteristic of membranes of the smooth endoplasmic reticulum. These results are consistent with the contention that endoplasmic reticulum is a site of phenylpropanoid and flavonoid metabolism in Hippeastrum.

Journal Article↗
PubMed2006

Benchmark dose for cadmium-induced renal effects in humans.

OBJECTIVES: Our goal in this study was to explore the use of a hybrid approach to calculate benchmark doses (BMDs) and their 95% lower confidence bounds (BMDLs) for renal effects of cadmium in a population with low environmental exposure. METHODS: Morning urine and blood samples were collected from 820 Swedish women 53-64 years of age. We measured urinary cadmium (U-Cd) and tubular effect markers [N-acetyl-beta-d-glucosaminidase (NAG) and human complex-forming protein (protein HC) ] in 790 women and estimated glomerular filtration rate (GFR; based on serum cystatin C) in 700 women. Age, body mass index, use of nonsteroidal anti-inflammatory drugs, and blood lead levels were used as covariates for estimated GFR. BMDs/BMDLs corresponding to an additional risk (benchmark response) of 5 or 10% were calculated (the background risk at zero exposure was set to 5%) . The results were compared with the estimated critical concentrations obtained by applying logistic models used in previous studies on the present data. RESULTS: For both NAG and protein HC, the BMDs (BMDLs) of U-Cd were 0.5-1.1 (0.4-0.8) microg/L (adjusted for specific gravity of 1.015 g/mL) and 0.6-1.1 (0.5-0.8) microg/g creatinine. For estimated GFR, the BMDs (BMDLs) were 0.8-1.3 (0.5-0.9) microg/L adjusted for specific gravity and 1.1-1.8 (0.7-1.2) microg/g creatinine. CONCLUSION: The obtained benchmark doses of U-Cd were lower than the critical concentrations previously reported. The critical dose level for glomerular effects was only slightly higher than that for tubular effects. We suggest that the hybrid approach is more appropriate for estimation of the critical U-Cd concentration, because the choice of cutoff values in logistic models largely influenced the obtained critical U-Cd.

Benchmarking↗
PubMed1983

Performance of broiler breeders on different feeding systems.

Two experiments were conducted in which broiler breeders were fed either at 0800, 1300, 1600 hr, ad libitum, or at 1300 hr followed by a calcium-phosphorus (Ca-P) supplement 3 hr later. The Ca-P supplement was 10.6 g/bird/day of pellets containing 5.2% P and 21.0% Ca. Experiment 1 was conducted with 64-week-old hens from July 27 to August 23. Experiment 2 was conducted with 32-week-old hens from November 5 to January 27. The birds that were fed at 1300 hr followed by Ca-P pellets at 1600 hr and those fed at 1600 hr laid eggs with higher specific gravity than did the birds fed at 0800 hr, 1300 hr, or ad libitum. The ad libitum-fed birds laid eggs with the lowest specific gravity. There were no significant differences in fertility or hatchability of fertile eggs attributed to different feeding times, although ad libitum-fed birds had lower fertility and hatchability. However, egg production was significantly higher for hens fed at 1300 hr with Ca-P pellets at 1600 hr than for birds fed ad libitum in Experiment 1. In Experiment 2, ad libitum-fed birds had significantly higher egg production than birds fed at 1300 hr. However, there were no significant differences in egg production among birds fed at different times.

Animals↗
PubMed1995

Biphasic edema development after experimental brain contusion in rat.

The time course of edema development following experimental brain contusion was studied by measuring cortex specific gravity 1 and 12 h after the trauma, and thereafter once daily until 7 days after the trauma. A biphasic development of edema was observed; the specific gravity decreased to a minimum on day 2 (P < 0.001), increased to an almost normal level on day 4 and thereafter decreased again to a second minimum 6 days after the trauma (P < 0.01). Delayed edema formation has been recognized in clinical settings, but has not been described in experimental studies. This study, with a prolonged daily follow-up, clearly demonstrates that a secondary phase of edema is an experimentally reproducible entity. The model will enable study of the pathogenetic mechanisms.

Animals↗
PubMed2001

Biological monitoring and exposure to mercury.

Occupational health professionals' interest in controlling mercury (Hg) exposure, and the use of biological monitoring in this context, has been ongoing for a number of years. Evidence from urinary Hg results in a number of UK firms who have undertaken some form of biological monitoring or occupational health surveillance suggest that exposure has decreased over the last 10-15 years. This decrease precedes the establishment in the UK of an advisory biological monitoring guidance value (HGV) for urinary Hg and the production of updated medical guidance from the Health & Safety Executive on Hg exposure (MS12 1996). This latter document recommends a urinary sampling interval for urinary Hg of between 1 and 3 months, which is consistent with the reported toxicokinetics of Hg excretion, but we highlight that urinary Hg represents integrated exposure over many previous months. Mercury is a recognized nephrotoxin and MS12 1996 mentions the use of regular dipstick protein estimations. We review our experience of investigating proteinuria and enzymuria in a large-scale cross-sectional occupational study. The incidence of Hg-induced renal disease is probably very rare at current exposure levels. Therefore acceptance of a high false-positive rate of proteinuria not related to Hg exposure needs to be considered in any urinary protein testing regime of Hg workers. The establishment of an HGV for urinary Hg has raised questions about the uncertainty associated with a urinary Hg result, including factors such as diurnal variation, whether urine correction by creatinine or specific gravity is preferable and the possibility of non-occupational sources of Hg contributing significantly towards breaching the HGV. Correction of urinary Hg results by creatinine or specific gravity and the use of a fixed sampling time, such as the beginning or end of the day, substantially reduce the uncertainty in a urinary Hg measurement. But even with good laboratory precision, an individual with a true urinary Hg excretion of 20 nmol/mmol creatinine could supply urine samples of between 14 and 26 nmol/mmol creatinine. The influence of dietary sources in the UK contributing to urinary Hg values approaching or exceeding the HGV is unlikely. The use of tribal or ethnic cosmetics and remedies needs to be considered if a urinary Hg result looks inappropriately high, as some such preparations have been found to contain Hg and can be absorbed through the skin. The ability of excessive chewers or teeth grinders who have a large number of dental amalgam fillings to breach the urinary HGV in the absence of substantial occupational Hg exposure has been reported in a few Scandanavian studies. We report here a likely case of this phenomenon. Since the establishment of the HGV, our biological monitoring Hg data from a number of industry sectors using inorganic or metallic Hg have suggested that a minority of samples (13%) are still greater than the HGV.

Cross-Sectional Studies↗
PubMed1986

Genotypic and phenotypic parameters of spur incidence and length in White Leghorn hens.

Spurs were measured on two groups of hens: at 532 days of age in six selected and three control strains (Expt. 1); and at 483 days of age in a full 3 X 3 diallel of three of the selected strains as well as two control strains and two commercial stocks (Expt. 2). There were no significant differences in length between spurs on right and left legs. Strain differences for spur incidence were large and significant, but those for length generally were not. Pooled strain estimates of heritability for spur incidence were .21 for both left and right spurs, and .40 (left) and .44 (right) for spur length (Expt. 1). General combining ability was large and highly significant for spur incidence only, and specific combining ability was not significant for either incidence or length of spurs (Expt. 2). Heterosis was not significant for spur incidence or length. Reciprocal differences were significant only for spur incidence of the crosses of strains 4 and 8. Spur length was negatively correlated phenotypically with egg production, egg weight, specific gravity, and Haugh units. Genotypically, spur length was positively correlated with part-record egg production to 273 days and negatively correlated with 450-day egg weight and specific gravity.

Animals↗