SEARCH · PubMed Health

Results for “Retention”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 487 records · Page 27Linked to original sources

PubMed1997

From vigilance to violence: mate retention tactics in married couples.

Although much research has explored the adaptive problems of mate selection and mate attraction, little research has investigated the adaptive problem of mate retention. We tested several evolutionary psychological hypotheses about the determinants of mate retention in 214 married people. We assessed the usage of 19 mate retention tactics ranging from vigilance to violence. Key hypothesized findings include the following: Men's, but not women's, mate retention positively covaried with partner's youth and physical attractiveness. Women's, but not men's, mate retention positively covaried with partner's income and status striving. Men's mate retention positively covaried with perceived probability of partner's infidelity. Men, more than women, reported using resource display, submission and debasement, and intrasexual threats to retain their mates. Women, more than men, reported using appearance enhancement and verbal signals of possession. Discussion includes an evolutionary psychological analysis of mate retention in married couples.

Adolescent↗

PubMed1994

Retention index of thallium-201 single photon emission computerised tomography (SPECT) as an indicator of metastasis in adenocarcinoma of the lung.

We examined the relationship between the retention of thallium-201 (201Tl) on a delayed scan and the metastatic potential of adenocarcinomas of the lung. We studied 43 patients with adenocarcinoma of the lung and divided them into two groups according to the presence or absence of lymph node metastasis. 201Tl single photon emission computerised tomography (SPECT) was conducted twice: 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 3 mCi of 201Tl chloride. We calculated the retention index in order to evaluate the degree of 201Tl retention in the primary tumour. The retention indices were significantly higher in the group that was positive for lymph node metastasis than in the negative group. In adenocarcinomas with high metastatic potential, 201Tl SPECT demonstrated slow washout or increased retention on the delayed scan. The retention index of 201Tl SPECT is a useful indicator of metastatic potential, thereby facilitating the prediction of prognosis, and provides insight into the relationship between 201Tl uptake and malignancy. This is the first report demonstrating a significant relationship between the retention of 201Tl SPECT and lymph node metastasis.

Adenocarcinoma↗

PubMed1996

Increased platelet retention in familial recurrent thrombotic thrombocytopenic purpura.

We studied two brothers with recurrent thrombotic thrombocytopenic purpura (TTP). Platelet retention, measured with a modified Adeplat S glass-bead test, was found to be increased during acute episodes of TTP and during remissions. Values of platelet retention ranged between 57 to 95% (normal range 16 to 34%). The continually elevated values enabled us to investigate which fraction of the patients' blood was responsible for the increased platelet retention and to evaluate the effect of different treatments on this parameter. We found that the patients' plasma increased the retention of normal platelets and of platelets taken from a patient with von Willebrand's disease type III. This activity was located in the cryoprecipitate fraction of plasma. Unusually large von Willebrand factor (vWF) multimers were demonstrated in both children during remission and decreased during relapse. Both fresh frozen plasma (FFP) and a commercial factor VIII/vWF concentrate reduced platelet retention when tested during remission. Treatment of both siblings with FFP or factor VIII/vWF concentrate was beneficial during recurrences. We conclude that the elevated platelet retention is due to a factor in the cryoprecipitate of the childrens' plasma, and that both FFP and factor VIII/vWF concentrate are effective in decreasing platelet retention.

Adult↗

PubMed1996

The role of central blood volume in the development of sodium retention in portal hypertensive rats.

BACKGROUND & AIMS: In portal hypertension, peripheral vasodilatation (PVD) causes Na+ retention as a result of vascular underfilling. The central blood volume is responsible for the vascular filling signals to baroreceptors and volume receptors. The aim of this study was to determine the role of central blood volume in Na+ retention in portal hypertensive rats. METHODS: Mean arterial pressure, portal pressure, cardiac output, total peripheral resistance, central blood volume, and extracellular Na+ space were assessed daily in rats after portal vein ligation or sham operation until a hyperdynamic circulatory state developed. RESULTS: On day 1, portal vein-ligated rats had PVD and a diminished central blood volume (1.26 +/- 0.04 vs. 1.47 +/- 0.09 mL/100 g body wt; P < 0.05). On day 2, Na+ space increased in portal vein-ligated rats (38.1 +/- 0.5 vs. 33.1 +/- 0.5 mL/100 g body wt; P < 0.01). From day 2 on, normalization of central blood volume and cessation of Na+ retention were observed despite persistent PVD. On day 4, portal vein-ligated rats developed a hyperdynamic circulatory state with a normal central blood volume and persistent PVD. CONCLUSIONS: Although total peripheral resistance remains decreased, Na+ retention ceases after central blood volume is normalized. Central blood volume therefore appears to be the signal for Na+ retention. Although PVD persists after Na+ retention ceases, it may contribute to Na+ retention by decreasing central blood volume.

Animals↗

PubMed2002

Comparison of thallium-201 uptake and retention indices for evaluation of brain lesions with SPECT.

Thallium-201 chloride single photon emission computed tomography ((201)TlCl SPECT) has been applied extensively for studies of human tumors. To assess which indices for (201)TlCl SPECT are most useful for diagnosing brain lesions, a total of 82 patients (98 images) with intracranial abnormalities were investigated. Seventy-six cases with abnormal (201)Tl uptake were evaluated in terms of six different (201)Tl uptake and retention indices: (1) average early (201)Tl uptake = Av.Le/Av.Be; (2) maximum early (201)Tl uptake = Mx.Le/Av.Be; (3)(201) Tl retention A = Av.Ld/Av.Le; (4) (201)Tl retention B = Mx.Ld/Mx.Le; (5) (201)Tl retention C = (Av.Ld/Av.Bd)/(Av.Le/Av.Be); (6) (201)Tl retention D = (Mx.Ld/Av.Bd)/(Mx.Le/Av.Be), where Av.Le and Mx.Le are average and maximum early counts for lesions, Av.Be and Av.Bd are average early and delayed counts for contralateral normal brains, and Av.Ld and Mx.Ld are average and maximum delayed counts for lesions. Comparison of patients with benign and malignant lesions did not demonstrate significant differences with any of the indices. However, low (I-II) and high (III-IV) grade astrocytomas varied in their average and maximum early (201)Tl uptake indices (both P = 0.0026). For patients with and without meningiomas, P values for indices of maximum early(201) Tl uptake and (201)Tl retention A and B were 0.0338, 0.0005, 0.0002, respectively. While comparison of patients with metastatic brain tumors and gliomas again showed no significant differences between the groups, the presence or absence of calcification was associated with significant variation in all the indices. With (201)TlCl-SPECT imaging, the average and maximum early (201)Tl uptake indices are appropriate for the assessment of tumor viability or malignancy, while (201)Tl retention indices (A,B) are useful for tumor differentiation, especially with meningiomas. Choice of suitable indices should enhance the utility of (201)TlCl-SPECT imaging in pre- and postoperative evaluation of intracranial lesions.

Adolescent↗

PubMedDate not supplied

[Intracellular retention of cytarabine-triphosphate (Ara-CTP) in blasts of children with acute lymphoblastic leukemia. Correlation with clinical course parameters].

BACKGROUND: Cellular uptake and intracellular phosphorylation to the nucleotide cytosine arabinoside-triphosphate (Ara-CTP) is the precondition for the cytostatic effect of cytarabine. The pharmacokinetics of Ara-CTP in leukemic cells was reported to be of clinical importance in adult nonlymphoblastic leukemia. Therefore, the role of intracellular Ara-CTP formation and retention was investigated in blast cells from children with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: At the time of diagnosis, peripheral or bone marrow blast cells from 41 children with ALL and 13 with relapsed ALL were incubated in Ara-C containing medium (1 hour, 1 or 3 micrograms/ml) followed by reincubation in Ara-C free medium (3 h). Intracellular Ara CTP formation and Ara-CTP retention were determined. MAIN RESULTS: Ara-CTP formation did not show marked differences between the different immunological subtypes. Ara-CTP retention, however, was significantly lower in T-ALL (37 +/- 15%, n = 8) compared to non-T-ALL (67 +/- 25%, n = 33; p < 0.003). Ara-CTP retention was also significantly different in children with and without persistence of peripheral blast cells after one week of prednison treatment (71 +/- 30%, n = 9 and 53 +/- 19%, n = 21; p = 0.031) as well as in children with and without complete bone marrow remission on day 15 of the ALL-BFM treatment protocol (66 +/- 17%, n = 19 and 43 +/- 18%, n = 11; p = 0.018). Ara-CTP retention was inversely correlated with the risk groups defined by the ALL-BFM treatment protocols (standard 79 +/- 29, intermediate 59 +/- 25, high risk 47 +/- 21%). A trend towards lower Ara-CTP retention was observed in relapsed leukemias (relapsed non-T-ALL 51 +/- 17%, p = 0.061). The difference in the probability of event free survival (following risk group adapted treatment according to ALL-BFM trials) between children with high (> or = 72%; 0.92 +/- 0.08) and low (< 72%: 0.58 +/- 0.15) Ara-CTP retention up to now did not reach statistical significance (p = 0.12). CONCLUSIONS: The more rapid decrease of cellular Ara-CTP in T-cell leukemia and children at higher clinical risk groups provide a pharmacokinetic rationale for prolonged infusion duration as an alternative to the intensification by dose escalation alone.

Adolescent↗

PubMed2001

Dual cell seeding and the use of zymogen tissue plasminogen activator to improve cell retention on polytetrafluoroethylene grafts.

OBJECTIVE: The purpose of this study was to enhance the retention of seeded endothelial cells (EC) on prosthetic vascular grafts. Dual-layer EC and smooth muscle cell (SMC) seeding and gene transfer of a zymogen tissue plasminogen activator gene (tPA) into seeded EC were studied. METHODS: Polytetrafluoroethylene (PTFE) grafts were precoated with fibronectin, seeded with SMC followed by EC a day later, and then, 24 hours later, exposed to an in vitro flow system for 1 hour. Cell retention rates were determined for grafts seeded with EC only, a dual layer of EC on top of SMC, EC transduced with wild-type tPA, and EC transduced with zymogen tPA. RESULTS: Seeding efficiency of PTFE pretreated with fibronectin was 260 +/- 8 cell/mm(2). After exposure to flow, only 39% +/- 14% of the EC were retained when EC were seeded alone, whereas 73% +/- 22% of EC remained on grafts when EC were seeded on top of SMC (P <.001, n = 10). The enzyme activity of a mutant zymogen tPA in absence of fibrin was 14 +/- 1 IU/mL, which is 3.6-fold lower than that in the presence of fibrin (50 +/- 19 IU/mL), whereas fibrin has no effect on the wild-type tPA activity. EC expressing a high level of wild-type tPA had a lower retention rate (37%) when compared with normal EC (45%). EC expressing the mutant zymogen tPA had an improved retention rate (54%, P =.001, n = 10) in absence of fibrin, whereas its retention rate was reduced to 43% when the cells were exposed to fibrin. CONCLUSION: SMC seeded between EC and PTFE improves EC retention in vitro. Transduction of zymogen tPA increases thrombolytic ability of seeded cells with less adverse impact on cell retention than wild-type tPA.

Blood Vessel Prosthesis↗

PubMed1995

The cytoplasmic and N-terminal transmembrane domains of cytochrome P450 contain independent signals for retention in the endoplasmic reticulum.

Microsomal cytochrome P450 is inserted into the membrane of the endoplasmic reticulum (ER) by its N-terminal signal/anchor sequence which also functions as an ER retention signal. To analyze further potential retention signals of cytochrome P450, topological domains of cytochrome P450 2C1 or 2C2, epidermal growth factor receptor, a plasma membrane protein, and bacterial alkaline phosphatase, a secreted protein were exchanged. The N-terminal signal/anchor of cytochrome P450 2C1 functioned as an ER retention signal when placed at the N terminus of several reporter proteins but not when fused at the C terminus of the extracellular domain of epidermal growth factor receptor, with or without a heterologous cytoplasmic domain. Chimeric proteins in which the cytoplasmic domain of cytochrome P450 2C2 was substituted for that of epidermal growth factor receptor were retained in the ER indicating that an independent retention signal is present in the cytoplasmic part of cytochrome P450 2C2. These chimeras were enzymatically active which argues against misfolding as the primary cause of retention. The ER retention signal of the cytoplasmic domain could not be localized to a single amino acid segment by deletion analysis. These results show that cytochrome P450 2C2 contains redundant, complex ER retention signals in its cytoplasmic and N-terminal hydrophobic domains and that the function of the N-terminal signal is context-dependent.

Alkaline Phosphatase↗

PubMed2000

Masking of an endoplasmic reticulum retention signal by its presence in the two subunits of the asialoglycoprotein receptor.

Human asialoglycoprotein receptor H1 and H2b subunits assemble into a hetero-oligomer that travels to the cell surface. The H2a variant on the other hand is a precursor of a cleaved soluble form that is secreted. Uncleaved H2a precursor molecules cannot exit the endoplasmic reticulum (ER), a lumenal juxtamembrane pentapeptide being responsible for their retention. Insertion of this pentapeptide into H1 (H1i5) causes its complete ER retention but not fast degradation as happens to H2a. Cotransfection of H2a elicited, by heterodimerization, the Golgi processing of H1i5 and its surface expression. This occurred to a much lesser extent by cotransfection of H2b. Likewise, coexpression of H1i5 and not H1 stabilized H2a and caused its export to the cell surface. Homodimerization of molecules containing the pentapeptide did not cancel the retention. Thus, only when the pentapeptide is present in both subunits is the ER retention efficiently abrogated. The results show the unexpected finding that identical ER retention signals present in two associated chains can mask and cancel each other's effect. This could have important implications as similar abrogation of ER retention of other proteins could eventually be obtained by engineering and coexpressing an associated protein containing the same retention signal.

3T3 Cells↗

PubMedDate not supplied

Issues to consider when predicting retention in therapeutic communities.

Many studies have focused on retention in therapeutic communities (TCs) because research shows that retention is an important predictor of client outcomes from these programs. A comparison of the three largest studies found there was little overlap between predictors of retention in TCs. Treatment Outcome Prospective Study data were analyzed to assess whether these findings may have been due to differences in times when the data were collected, measures of length of stay, and domains of variables used to predict retention. While the results suggest that each of these factors contributed to some differences between predictors of retention, the predictors still were unable to explain more than a small amount of the variance in retention. Research indicates that other variables need to be taken into account if future studies are to be more successful in predicting retention in TCs.

Adult↗

PubMed2000

Negative side-effects of retention sutures for abdominal wound closure. A prospective randomised study.

OBJECTIVE: To assess the effect of retention sutures on the postoperative course of patients after major abdominal operations. DESIGN: Prospective, randomised study. SETTING: Teaching hospital, Germany. SUBJECTS: 95 patients who were at increased risk of wound failure after major abdominal operations. INTERVENTION: Conventional mass closure either with (n = 44) or without (n = 51) reinforcement by wire retention sutures. MAIN OUTCOME MEASURES: Pain intensity on postoperative days 3, 6, 9, and 12, patients' acceptance, retention-suture-related morbidity, general morbidity. RESULTS: Postoperative pain was overall more severe with retention sutures. On day 6, 31/49 control patients but only 13/41 patients with retention sutures were pain-free (p = 0.003, 95% CI 0.12 to 0.51). Twelve of 44 patients with retention sutures developed local complications of the sutures, and 21 of the 44 had to have them removed prematurely, in most cases because of intolerable pain. CONCLUSIONS: Retention sutures used to close abdominal wounds cause inconvenience, pain, and specific morbidity.

Abdominal Muscles↗

PubMed1982

[Growth studies of fattening hybrid heifers. 3. Studies of the total retention of fattening hybrid heifers under different energy supply].

These investigations show that daily retention in the course of growth is subject to dynamic changes specific for each nutrient. While there are only insignificant differences between daily live weight growth as the practically usable parameter and body weight growth, daily dry matter deposition takes a comparatively different development. The specific development of dry matter deposition depends on the daily retention of protein and fat. Whereas in early age protein retention is higher, fat retention increases in the course of live weight development in dependence on the energy level. Different energy supply results in distinctly differentiated protein, fat and energy retention per day. The highest variation in daily retention could be ascertained for fat retention in dependence on energy supply. A comparison of the cumulated experimental results with model values generalised from the growth function corresponded well.

Animals↗

PubMed1997

Retention and utilization of amino acids in piglets fed ad libitum or restrictively diets supplemented with organic acids.

In a metabolic trial 4 groups of 8 piglets of 5 kg weight each were kept individually for 45 days (final weight 23 kg) and fed a practical diet. At the beginning of the experiment the body amino acid contents of an additional group of 8 piglets were determined by carcass analysis, and at the end of the experiment the body amino acid contents of the 4 test group piglets (A = control fed ad libitum, B and C = supplement of 1.5% fumaric acid fed ad libitum or restrictively, D = supplement of 1.5% citric acid fed ad libitum) were also analysed. The amino acid retention during the experimental period was determined by difference. The supplements of fumaric or citric acid did not influence the amount of the amino acid retention. The quotient of amino acid retention to amino acid consumed or the "productive amino acid value" was calculated and the maintenance requirements of essential amino acids for piglets were used to estimate the productive amino acid value for both retention and maintenance. The mean amino acid retention amounted to about 56 g/d, i.e. 3.49 g/kg W0.75.d of essential amino acids. The essential amino acid requirements for maintenance was 2.0 g, i.e. 0.29 g/kg W0.75.d, showing a variation of 4% (Leu) to 20% (Met+Cys) when related to the amount of the corresponding amino acid retention. With regard to the amino acid pattern for retention of the nutritionally most important amino acids, the following ratios were found: Lys, 100 (6.27 g/16 g N): Met+Cys, 48 (3.03 g): Thr, 56 (3.49 g): Trp, 13 (0.80 g). The productive amino acid values ranged from 40% (Trp), 55% (Thr), 66% (Met) to 80% (Lys). Under the conditions investigated, neither the supplements of organic acids nor the feed restriction influenced the amino acid utilization.

Amino Acids↗

PubMed1958

Response of potassium retentivity and survival of yeast to farultraviolet, near-ultraviolet and visible, and x-radiation.

Potassium retentivity and survival of yeast were studied after exposure to various kinds and conditions of irradiation. The radiations used were: 2537 A ultraviolet, 3500 to 4900 A long-ultraviolet and short visible, and 250 kvp(1) x-rays. Both potassium retentivity and survival are decreased by these radiations. The dose-response of survival is about 16 times as sensitive as is potassium retentivity after 2537 A irradiation. Potassium retentivity is about twice as sensitive as survival after irradiation of 3500 to 4900 A. Survival after x-irradiation under aerobic conditions is five times as sensitive as potassium retentivity. Survival of cells irradiated with x-rays under anaerobic conditions was about half as sensitive as under aerobic conditions. The response of potassium retentivity to x-radiation at 25 degrees C. under anaerobic conditions is only slightly affected below 160 kr, at which dose the slope abruptly increases to that obtained under aerobic conditions; lowering the temperature to 0 degrees C. moves this point to about 300 kr. These differential effects are indicative of interaction of radiations with the yeast cell at sites that independently control survival and the retention of potassium.

Cell Survival↗

PubMed1995

Implications of airway retention for radiation doses from inhaled radionuclides.

A slow phase of bronchial and bronchiolar clearance ('airway retention') has been included in the revised dosimetric model for the human respiratory tract recently adopted by the International Commission on Radiological Protection (ICRP), based primarily on the results of the bolus clearance experiments conducted by Stahlhofen et al. The treatment of airway retention in the new ICRP model is described. An analysis was carried out of the sensitivity of the equivalent lung dose, and the effective dose, to assumptions made in the new model about the extent of airway retention. It was shown that inclusion of airway retention of material deposited in the bronchial tree does have a significant effect on both end-points (of the order of 10-50%) for a wide range of radionuclides. In some cases, notably moderately soluble forms of long-lived alpha-emitters, its inclusion increases these doses by up to a factor of three, so that it makes the dominant contribution to the calculated dose. The model assumes that material in transit through the bronchial tree, having initially deposited in the alveolar region, is not subject to airway retention. Including retention of this material would typically increase doses by a further factor similar to that resulting from the airway retention of the bronchial deposit.

Absorption↗

PubMed1997

Lactation and weight retention.

The effect of lactation on weight retention was investigated longitudinally, with data collected at 0.5, 2, 4, 6, 12, and 18 mo after parturition in 110 women aged 20-40 y who had been nulliparous or primiparous. At each evaluation women were categorized as fully breast-feeding, partly breast-feeding, or bottle-feeding including infants weaned to a bottle (bottle feeding/weaned). Postpartum weight retention was calculated by subtracting weight before pregnancy from weight at each evaluation. Lactation practices were found to be significantly associated (P < 0.05) with postpartum weight retention by longitudinal regression analysis. Women who bottle-fed their infants retained more weight over time than women who breast-fed their infants. Significantly slower rates of weight loss were observed when women ceased breast-feeding or switched from fully to partly breast-feeding. Weight retention over time was greater in women who were older, unmarried, or had greater weight gain during pregnancy (P < 0.05). A pattern of weight gain rather than weight loss was observed in unmarried women. Our findings suggest that lactation influences the pattern of postpartum weight retention; however, the effect of lactation on weight retention was sufficiently limited to warrant minimal emphasis on lactation as a means of minimizing postpartum weight retention.

Adult↗

PubMed2004

Breastfeeding and postpartum weight retention in a cohort of Brazilian women.

BACKGROUND: The relation between postpartum weight retention and breastfeeding practices is controversial. OBJECTIVE: Defining breastfeeding as the period when a child is exclusively or predominantly breastfed, we studied the association between breastfeeding duration and postpartum weight retention. DESIGN: We followed 405 women aged 18-45 y who were assessed at 0.5, 2, 6, and 9 mo postpartum. The outcome variable, postpartum weight retention, was expressed as the difference between the observed weight at each follow-up and the reported prepregnancy weight. The main statistical procedure used was the longitudinal mixed-effects model. RESULTS: Mean postpartum weight retention at the end of the study was 3.1 kg. Single women aged > or = 30 y retained more weight than did younger single women or married women. The combined effect of breastfeeding duration and percentage of body fat at baseline was significant only for women with < 30% body fat. According to the model's prediction, when women who had 22% body fat and breastfed for 180 d were compared with those who had 22% body fat and breastfed for only 30 d, each month of breastfeeding contributed -0.44 kg to postpartum weight retention. When only the percentage of body fat was varied, the total effect was 3.0, 1.7, 1.2, and 0.04 kg in women with 18%, 25%, 28%, and 35% body fat, respectively. CONCLUSIONS: These results support the hypothesis of an association between breastfeeding and postpartum weight retention and suggest that encouraging prolonged breastfeeding might contribute to decreases in postpartum weight retention.

Adolescent↗

PubMed2005

Long-term high copper intake: effects on copper absorption, retention, and homeostasis in men.

BACKGROUND: Numerous studies have examined the effect of low and adequate intakes of copper on absorption and retention, but little information is available on the regulation of absorption and retention of copper when intake is high. OBJECTIVE: A study was conducted in men to determine the effect of long-term high copper intake on copper absorption, retention, and homeostasis. DESIGN: Nine men were confined to a metabolic research unit (MRU) for 18 d and were fed a 3-d rotating menu containing an average of 1.6 mg Cu/d. They continued the study under free-living conditions for 129 d, supplementing their usual diets with 7 mg Cu/d. They then returned to the MRU for 18 d and consumed the same diet as during the first period, except that copper intake was 7.8 mg/d. The stable isotope (63)Cu was fed to 3 subjects and infused into the other 6 on day 7 of each MRU period, and complete urine and stool collections were made throughout the study. Total copper and (63)Cu were determined by inductively coupled plasma mass spectrometry. Copper absorption, excretion, and retention were calculated on the basis of dietary, urinary, and fecal copper and (63)Cu. RESULTS: Results were as follows when comparing the high copper intake with the usual intake: fractional copper absorption was significantly lower, but the amount absorbed was significantly higher; excretion of the infused (63)Cu was significantly faster; and total retention was significantly higher. CONCLUSIONS: Homeostatic regulation of copper absorption and retention helped to minimize the amount of copper retained with high copper intake but was not sufficient to prevent retention of >0.6 mg Cu/d.

Administration, Oral↗