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PubMed1983

Effects of selenium, vitamins, and ration fiber on placental retention and performance of dairy cattle.

One hundred and twenty Holstein cows were assigned to a randomized complete block design to determine effects of selenium, vitamins, and ration fiber on incidence of placental retention and other health and reproductive problems. The selenium treatment (50 mg selenium, 680 IU vitamin E) was administered as a single injection approximately 3 to 4 wk prepartum. The vitamin treatment (3 million IU vitamin A, 450,000 IU vitamin D3, 300 IU vitamin E) consisted of two injections, one administered at 3 to 4 wk prepartum and another at 2 to 3 wk postpartum. Fiber treatments were: control, 15.7% crude fiber; beet pulp, 19.3% crude fiber; and soyhull, 19.0% crude fiber. Feeding of experimental rations was begun 1 day postpartum, and the ration effect on placental retention was examined only at subsequent parturition. The overall placental retention rate of 28% was not affected by either selenium, vitamin, or combined treatments. Ration treatments did not affect the placental retention rate of 42% at subsequent parturition. Cows receiving the soyhull ration required fewer services per conception. Incidence of foot problems tended to be higher in the cows that received the combined selenium and vitamin A, D, E treatments. Supplemental selenium, vitamins A, D, and E, and ration fiber treatments did not reduce incidence of placental retention or improve most other health and reproductive measures.

Animals↗
PubMed1991

Enhanced in vitro uptake and retention of 3H-tetraphenylphosphonium by nervous system tumor cells.

Photodynamic therapy is a promising treatment for human brain tumors because of the selective retention of certain compounds by tumor cells. Certain lipophilic cationic compounds, such as tetraphenylphosphonium (TPP), are selectively taken up by a variety of carcinomas. Although preferential retention of TPP has been demonstrated for the breast carcinoma cell line MCF-7, this compound had not been tested previously on cells derived from nervous system tumors. In the present study, tritiated-TPP (3H-TPP) uptake and retention for eight different cell cultures of three histologically different types of nervous system tumors was measured and the data were compared to a positive control (MCF-7) and negative controls (normal African Green monkey kidney epithelium (CV-1) and the normal human fibroblast (WI-38) cell lines). Uptake and retention characteristics could be grouped by specific pathological tumor types, but individual tumor variability was notable. Malignant astrocytoma (grade III/III glioblastoma) and malignant neurofibrosarcoma cells showed preferential uptake and retention of 3H-TPP relative to meningioma cells and normal controls. A clonogenic assay utilizing the cytotoxic lipophilic cationic compound dequalinium showed strong retainers of 3H-TPP to be more susceptible to the effects of dequalinium than weak retainers. These data demonstrate that certain human and experimental animal nervous system tumor cell lines retain lipophilic compounds possessing a delocalized positive charge. Lipophilic cationic compounds may be useful in the intraoperative delineation of tumor margins and in the photodynamic therapy of certain nervous system tumors.

Animals↗
PubMed1983

Effect of fat retention on the rachitogenic effect of rye fed to broiler chicks.

Two experiments were conducted to determine the influence of fat retention on bone mineralization and amino acid retention for broiler chicks fed rye diets containing marginal levels of vitamin D3. In Experiment 1, rye diets containing tallow were supplemented with high vitamin D3, bile salt (sodium taurocholate), or a detergent (sodium lauryl sulphate). Fat retention and tibia ash were improved (P less than .05) with bile salt addition, and tibia ash alone (P less than .05) was improved when high vitamin D3 or the detergent was added to the diet. In Experiment 2, rye diets contained tricaprylin (TC), tristearin (TS), or triolein (TO) as a fat source. Both fat retention (TS less than TO less than TC) and tibia ash (TS less than TC less than TO) showed a significant (P less than .05) treatment effect. The results of both experiments support the hypothesis that the rachitogenic effect of feeding rye may be related to inadequate fat digestion. There was no significant treatment effect on amino acid retention in either experiment. A third experiment indicated a similar bile acid pool size for chicks fed rye as opposed to wheat; however, bile acid concentration of jejunal fluid was lower (P less than .05) for chicks fed rye. A possible microbial involvement in the disturbance of bile acid metabolism was indicated by the capacity of Streptococcus organisms derived from chick small bowel to degrade sodium taurocholate.

Amino Acids↗
PubMed1986

Effects of calcium and phase-feeding phosphorus on production traits and phosphorus retention in two strains of laying hens.

Three levels of dietary Ca (3.0, 3.5, or 4.0%) were fed throughout a 336-day experiment to two strains of Single Comb White Leghorn hens in a factorial arrangement with three P feeding programs: .64% P fed continuously; .56, .49, and .39% P; or .64, .54, and .44% P fed when hens were 24 to 36, 36 to 52, and 52 to 72 weeks, respectively. In addition to production traits, measurements of P retention were made at 34, 42, 50, 62, and 72 weeks of age. No dietary effects were observed on production traits. Average P retention over the entire experiment was 104, 148, and 178 mg/day when hens were fed 3.0, 3.5, and 4.0% Ca, respectively. Most of the favorable effect of Ca on P retention occurred after 50 weeks of age. However, increasing dietary Ca had an adverse influence on P retention at 42 weeks, when ambient temperature was unusually hot and feed intake decreased markedly. Significant P effects were observed when hens were 42 and 72 weeks of age. At these times, hens fed .64% P retained the most P while those phase fed .56, .49, and .39% P retained at least. Retention of P tended to decline with increasing age of the hens. Overall, the hens were in a state of marginal to negative P balance at 42, 62, and 72 weeks of age even when P deposited in eggs was considered.

Animals↗
PubMed2004

Interaction of retention interval with CS-preexposure and extinction treatments: symmetry with respect to primacy.

Imposition of a retention interval between cue-outcome pairings and testing can alleviate the retardation of conditioned responding induced by pretraining exposure to the cue (i.e., the CS-preexposure effect). However, recent studies have reported an enhanced effect of CS-preexposure treatment with longer retention intervals (De la Casa & Lubow, 2000, 2002; Lubow & De la Casa, 2002). In a series of conditioned barpress suppression studies with rats, we examined the effects of imposing a retention interval just prior to testing following either CS-preexposure (cue alone before cue-outcome pairings) or extinction (cue alone after cue-outcome pairings) treatments. Experiment 1 replicated in a different preparation recent reports of CS-preexposure treatment effects increasing with longer retention intervals. Experiment 2 showed that spontaneous recovery of stimulus control of behavior after extinction can be obtained with the same parameters as those used to observe the augmented effect of CS-preexposure treatment. In Experiment 3, both the augmented effect of CS-preexposure treatment and spontaneous recovery from extinction were found when we used, in place of a retention interval, an associative priming manipulation.

Animals↗
PubMed2006

Sodium and water retention in heart failure and diuretic therapy: basic mechanisms.

The pathophysiology of sodium and water retention in heart failure is characterized by a complex interplay of hemodynamic and neurohumoral factors. Relative arterial underfilling is an important signal that triggers heart failure-related sodium and water retention. The response to perceived arterial underfilling is modulated by the level of neurohormonal activation, the degree of renal vasoconstriction, and the extent to which renal perfusion pressure is reduced. Sodium retention can also be exceeded by water retention, with the result being dilutional hyponatremia. Sodium and water retention in heart failure also function to dampen the natriuretic response to diuretic therapy. The attenuated response to diuretics in heart failure is both disease-specific and separately influenced by the rate and extent of diuretic absorption, the rapidity of diuretic tubular delivery, and diuretic-related hypertrophic structural changes that surface in the distal tubule.

Body Water↗
PubMed2002

Workforce retention in rural and remote Australia: determining the factors that influence length of practice.

OBJECTIVES: To ascertain which factors are most significant in a general practitioner's decision to stay in rural practice and whether these retention factors vary in importance according to the geographical location of the practice and GP characteristics. DESIGN: National questionnaire survey. The method of paired comparisons was used to describe the relative importance of the retention items. SETTING: Non-metropolitan Australia, September 2001. PARTICIPANTS: A stratified sample of all rural GPs practising during April-June 2001. MAIN OUTCOME MEASURES: A rank ordering of factors influencing how long GPs stay in rural practice, and an index of their relative perceived importance. RESULTS: Professional considerations -- overwhelmingly, on-call arrangements -- are the most important factors determining GP retention in rural and remote areas. Rural doctors consistently ranked on-call arrangements, professional support and variety of rural practice as the top three issues, followed by local availability of services and geographical attractiveness. Proximity to a city or large regional centre was the least important factor. Retention factors varied according to geographical location and GPs' age, sex, family status, length of time in the practice, and hospital duties. CONCLUSIONS: A broad, integrated rural retention strategy is required to address on-call arrangements, provide professional support and ensure adequate time off for continuing medical education and recreation.

Australia↗
PubMedDate not supplied

The relationship between the profile of severity of addiction and the retention of patients in the ambulatory program of DDTP.

OBJECTIVES: The authors described some variables related to the retention of drug dependent veterans receiving outpatient treatment at San Juan V.A.M.C. and compared the profile of addiction severity with retention using a global dysfunction scale. METHODS: The clinical charts of 74 patients were examined at random using a 16-item questionnaire based on the ASI scale. The data was processed and analyzed using the Epi Info V6.2 computer program, utilizing chi square as the main statistics. RESULTS: The patient's retention in treatment for > or = to 3 months was associated with some specific variables such as: more than 12 years of education, being Catholic, divorced, living with parents, use of more than one drug of preference, having a negative urine toxicology result before treatment and after treatment, and showing a favorable change in urine toxicology results. In terms of severity of dysfunction, a considerable substance problem and an extreme legal problem were associated with a retention of > or = to 3 months, as well as no evidence of occupational problems. CONCLUSION: The strong correlation between specific variables and the retention of patients in treatment for > or = to 3 months should create awareness of the importance of available and effective treatments in the fight against substance abuse and mental health problems as well as to educate and integrate family members in patients treatment, since a supportive family member is one of the best tools that patients and therapist can have to help maintain patient's sobriety.

Adult↗
PubMed1999

Psychiatric comorbidity measures as predictors of retention in drug abuse treatment programs.

OBJECTIVE: To examine lifetime and current psychiatric comorbidity measures as predictors of drug abuse treatment retention, and to test the generalizability of results across treatment agencies in diverse settings and with varying practices. DATA SOURCES/STUDY SETTING: The national Drug Abuse Treatment Outcome Studies (DATOS), a longitudinal study of clients from 96 treatment agencies in 11 U.S. cities. STUDY DESIGN: The design is naturalistic and uses longitudinal analysis of treatment retention in long-term residential, outpatient drug-free, and outpatient methadone treatment modalities; client background (including psychiatric comorbidity) and program service provision are predictors. Clinical thresholds for adequate treatment retention were 90 days for long-term residential and outpatient drug-free, and 360 days for outpatient methadone. Psychiatric indicators included lifetime DSM-III-R diagnoses of depression/anxiety and antisocial personality, and dimensional measures of current symptoms for depression and hostility. DATA COLLECTION/EXTRACTION METHODS: Data include structured interviews with clients, a survey of treatment program administrators, and program discharge records. PRINCIPAL FINDINGS: Dimensional measures of current psychiatric symptoms emerged as better predictors than lifetime DSM-III-R diagnoses. In addition, the predictive association of hostility with retention varied significantly across treatment agencies, both in the long-term residential and outpatient drug-free modalities. Other notable findings were that on-site mental health services in long-term residential programs were associated with better retention for clients with symptoms of hostility. CONCLUSIONS: Assessment issues and stability of results across programs are important considerations for treatment research and practice.

Adult↗
PubMed1999

A record-retention program can protect group practices.

Group practices can benefit from having a systematic record-retention program that includes a formal record-retention policy. While state and Federal laws require the retention of some types of business records, many other records should be retained in the event of an audit or litigation. Having a record-retention program in place can help group practices respond cost-effectively and efficiently when called upon to produce documentation. The record-retention program should include a policy that stipulates not only which records should be kept but also for how long. Group practices should retain records relating to patient care, taxes, payroll, and contracts.

Cost-Benefit Analysis↗
PubMed2000

The effect of stanozolol on 15nitrogen retention in the dog.

The objective of the study was to determine the influence of either oral or intramuscular administration of stanozolol on nitrogen retention in dogs by using a non-invasive 15N-amino acid tracer technique. Ten healthy, intact, adult male sled dogs received either stanozolol tablets, 2 mg/dog PO, q12h, for 25 days (Group 1, n = 5) or an intramuscular injection of 25 mg of stanozolol on Days 7, 14, 21, and 28 (Group 2, n = 5). A 15N amino acid (5.27 mmol) was infused intravenously into each dog on Day 0 (before stanozolol treatment) and on Day 31 (after stanozolol treatment). Urine was collected by catheterization from each animal 3 times daily for 3 consecutive days. The 15N-urea enrichment in urine was determined by high-resolution mass spectrometry and the total amount of urea in the urine was determined. Both oral and injectable stanozolol resulted in significant (P < 0.05) increases in amino acid nitrogen retention compared to pretreatment values. Oral stanozolol increased nitrogen retention from 29.2 +/- 8.2% to 50.3 +/- 9.2%, while stanozolol injection increased nitrogen retention from 26.6 +/- 9.9% to 67.0 +/- 7.5%. The response to intramuscular administration was significantly greater than the response to the oral dosing regime. Stanozolol increases amino acid nitrogen retention in dogs, as has been previously observed in rats. This action of stanozolol may be beneficial in dogs under stress of surgical trauma and chronic disease.

Administration, Oral↗
PubMed2001

Delivery systems for BMPs: factors contributing to protein retention at an application site.

BACKGROUND: Recombinant human bone morphogenetic proteins (rhBMPs) are being tested in clinical studies for their capacity to elicit bone formation. Biomaterials used in delivery systems also play a critical role in supporting the osteoinductive activity of BMPs, attributable to the controlled presentation of the BMPs to target cells. Despite extensive preclinical studies, the factors contributing to local rhBMP pharmacokinetics remain to be elucidated. METHODS: The rhBMP pharmacokinetics were studied in a rat subcutaneous implant and in an intramuscular injection model. In situ levels of rhBMPs were quantitated with use of 125I-labeled tracers. The effects of protein structural features and the nature of the biomaterial implant were explored. Osteoinduction by biomaterial+rhBMP combinations was assessed by a semiquantitative, histology-based bone score. RESULTS: With the use of rhBMP-2, rhBMP-4, and an N-truncated rhBMP-2, the protein isoelectric point was found critical for the initial retention of rhBMPs in an implant. Osteoinduction studies carried out in parallel indicated that rhBMPs with a higher implant retention elicited more bone formation. In the clinically used collagen+rhBMP-2 device, collagen crosslinking and sterilization were most influential in rhBMP-2 retention. To increase retention at an application site, thermoreversible polymers were engineered and shown to enhance local rhBMP-2 retention, especially by injectable delivery. CONCLUSIONS: Two critical components of an osteoinductive device--namely, the biomaterial and the rhBMP--were shown to influence local protein pharmacokinetics and osteoinductive activity of the device. Designer biomaterials can provide an additional mechanism to modulate local protein pharmacokinetics. CLINICAL RELEVANCE: These studies form the foundation of next-generation osteoinductive devices with improved potency at sites of desired bone regeneration and reduced side effects at other sites.

Animals↗
PubMed1998

[Study on the retention behaviour and mechanism of organic acids on an anion exchanger].

The retention behaviour and mechanism of organic acids on an anion exchange column Shim-pack IC-A1 (Shimadzu, Japan) have been studied. The retention valences (x) of organic acids on the anion exchanger were measured based on the following equation: logk' = -(x/y)log[Eluent] + constant By using the linearity of logk' vs log[Eluent] and the retention valences, the retention mechanisms of organic acids can be predicted. Acetic acid eluted as the non-dissociated form by a non ion exchange mechanism, because its retention valence was only 0.21. In this work, the multi-peak for one organic acid was observed. The chromatograms of citric acid obtained using PyA eluent with different concentration were showed. Two peaks were observed. As eluent concentration decreased, the detection sensitivity (peak area) was increased due to the decrease of the background conductivity. The multiple peaks of citric acid were also observed when the mixture of phthalic acid(PhA) and trihydroxymethylaminomethane (TRIS) was used as eluent. The multi-peaks for one organic acid result from the fact that different forms of the organic acid can be separated each other on anion exchanger by ion-exchange mechanism. The two peaks of citric acid were caused by separation of mono- and divalent citrate anion.

Antiporters↗
PubMed2001

Posttraining infusion of norepinephrine and corticotropin releasing factor into the bed nucleus of the stria terminalis enhanced retention in an inhibitory avoidance task.

The present study investigated whether the bed nucleus of the stria terminalis (BNST) is involved in formation and retrieval of affective memory. Male Wistar rats with cannulae bilaterally implanted into the BNST were trained on a one-trial step-through inhibitory avoidance task. Shortly after training they received bilateral intra-BNST infusion of lidocaine, various noradrenergic drugs, or corticotropin releasing factor (CRF). Results showed that posttraining intra-BNST infusion of lidocaine impaired retention. Posttraining intra-BNST infusion of norepinephrine or the alpha1 antagonist prazosin induced a dose- and time-dependent retention enhancement or deficit, respectively. The enhancing effect of norepinephrine was mimicked by the alpha1 agonist phenylephrine, and antagonized by prazosin at a non-impairing dose. Posttraining intra-BNST infusion of the alpha2 antagonist idazoxan or the beta antagonist propranolol failed to affect retention. Posttraining intra-BNST infusion of CRF also enhanced retention in a dose-dependent manner. Various drugs infused shortly before testing did not significantly influence locomotor activity and retention. These findings, taken together, suggest that the BNST is involved in memory formation processes for affective experience and norepinephrine released in the BNST acting via alpha1 receptors plays a critical role in this function.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

The impact of a College of Nursing Retention Program on the graduation rates of nursing students.

This study was designed to measure the impact of a College of Nursing's (CON) Retention Program on students enrolled in a baccalaureate degree nursing program. Within the last ten years, undergraduate nurses increasingly have utilized the CON retention program. These students traditionally face a number of barriers to their academic endeavors. This study was designed to assess the effect of the CON program on the barriers to academic success of students who entered the CON in the Fall classes of 1991, 1992 and 1993. The sample size was 320 students. The control group consisted of 137 students who received no intervention and the experimental group was comprised of 183 students who attended intervention sessions with the Retention Coordinator in the CON. It was hypothesized that the most successful students during this period (1991-1993) were the most frequent attendees of the CON retention program intervention sessions. The alternative hypothesis was that those persons who did not attend the sessions, but were still highly persistent and successful, were enrollees who had entered with high entrance credentials as demonstrated by the transfer grade point averages (GPA). The results of this study indicated the need, use and value of this systematic approach to retention.

Adaptation, Psychological↗
PubMed1992

Retention of a type II surface membrane protein in the endoplasmic reticulum by the Lys-Asp-Glu-Leu sequence.

Soluble luminal proteins of the endoplasmic reticulum (ER) are known to be retained by a tetrapeptide retention signal, KDEL. We report in this communication that the KDEL sequence when appended to the carboxy terminus of a cell surface membrane protein, dipeptidyl peptidase IV (DPPIV), resulted in its retention in the endoplasmic reticulum of transfected Madin-Darby canine kidney cells as assessed by indirect immunofluorescence. Selective surface biotinylation revealed that about 90-95% of the expressed DPPIV was retained in the ER. Appendance of the sequence KDEV did not, however, result in ER retention, illustrating the functional specificity of the retention signal. The ER retention was not due to misfolding of the mutant protein, as the mutant proteins remained enzymatically active. Our data suggest that the KDEL receptor is able to recognize and recycle type II membrane proteins containing a carboxyl-terminal KDEL sequence and postulates the existence of such yet to be identified endogenous proteins.

Amino Acid Sequence↗
PubMedDate not supplied

The comparative retention of National Health Service Corps and other rural physicians. Results of a 9-year follow-up study.

OBJECTIVE: To contrast the retention of physicians serving National Health Service Corps (NHSC) Scholarship Program obligations in rural settings to that of non-NHSC physicians working in the same or similar practices, and to identify promising retention-enhancing strategies. DESIGN: Cohort study. PARTICIPANTS: Four hundred twelve primary care physicians initially identified during an earlier study as working in a national stratified random sample of 178 externally subsidized rural clinics in 1981. Thirty-six percent were serving obligations to the NHSC, nearly all through the NHSC's Scholarship Program. The NHSC and non-NHSC inception cohorts (those first coming to their 1981 [or "index"] practices from May 1979 through December 1981) were created from within the entire group for use in most analyses. INTERVENTION: In 1990, physicians were resurveyed to learn of their backgrounds, experiences in their index practices, and their subsequent career moves. RESULTS: By 1984 and in each year thereafter, fewer NHSC than non-NHSC physicians of the entire respondent cohort remained (1) in their index practices, (2) in their index communities, and (3) in practice in any rural county (P less than .001). In the inception cohort, fewer NHSC than non-NHSC physicians were retained within all three settings by the third year after their initial dates of employment (P less than or equal to .01). After 8 years of employment, group retention rates for NHSC and non-NHSC inception cohort physicians were 12% vs 39% in the index practice and 29% vs 52% in nonmetropolitan practice. Physicians in both NHSC and non-NHSC groups who left their index practices generally left rural practice altogether. CONCLUSIONS: When compared to non-NHSC physicians working in comparable rural settings, the retention of rural NHSC physicians is seen to be poor and only partially explained by fixed physician, practice, or community variables. Long-term retention of NHSC providers is now receiving much needed attention at the federal level.

Adult↗
PubMed2004

[Correlation analysis of structures and gas chromatographic retention indices of aliphatic alcohols].

A characteristic value of atom i is defined as A(i) = (delta(i)v + sigma n(ij)v)/(1 + sigma n(ij)). Based on the adjacency matrix, an average valence connectivity index is set up by A(i) as (m)L = sigma (A(i), x A(j) x A(k)...)(-0.5). The first topological index (1)L among (m)L is defined as (1)L = sigma (A(i) A(j))(-0.5). Then (1)L of aliphatic alcohols were calculated. (1)L has good structural selectivity. (1)L and orientating group parameter (beta) have high correlativity with the gas chromatographic retention indices of 25 aliphatic alcohols on six different stationary phases (SE-30, OV-3, OV-7, OV-11, OV-17 and OV-25). A general linear regression equation is proposed as follows: I = a + b (1)L + cbeta, where I stands for the gas chromatographic retention index, a, b and c are regression coefficients. All the correlation coefficients were larger than 0.98. These models can better elucidate the change rule of the gas chromatographic retention indices for aliphatic alcohols. Moreover, using this model, the gas chromatographic retention indices of ten aliphatic alcohols have been predicted, and the results are quite satisfactory. It has been demonstrated that the quantitative structure-retention relationship (QSRR) models have good stability and predictability.

Chromatography, Gas↗