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PubMed1997

Urinary retention in the post-partum period. The relationship between obstetric factors and the post-partum post-void residual bladder volume.

OBJECTIVE: The three objectives of this study are: to investigate the incidence of post-partum urinary retention after vaginal delivery, to investigate the relationship between various obstetric parameters and the post-partum post-void residual bladder volume and to study the natural progression of the post-void residual bladder volume in patients with covert post-partum urinary retention. METHODS: Women who had a vaginal delivery (n = 691) in a teaching hospital during a 2-month period were studied. They were classified into three groups: normal patients, those with overt urinary retention, and covert urinary retention. Their day 1 post-partum post-void residual bladder volume were recorded and analyzed with respect to the obstetric parameters. Patients with covert retention were followed up daily with ultrasound to monitor their post-void residual volume. RESULTS: The incidences of overt and covert retention in our unit were 4.9% and 9.7%, respectively. The overall incidence of post-partum urinary retention after vaginal delivery was 14.6%. The duration of the first and second stages of labor were significantly associated with the post-partum post-void residual bladder volume. In all patients with covert retention, their post-void residual volume returned to normal within 4 days. CONCLUSION: Post-partum urinary retention is a common phenomenon that may be related to the process of parturition. Covert retention is a self-limiting phenomenon and specific treatment is unnecessary.

Adult↗

PubMed1992

Vasodilatation and sodium retention in prehepatic portal hypertension.

Sodium retention and peripheral vasodilatation are common consequences of portal hypertension secondary to cirrhosis. Although peripheral vasodilatation has been extensively documented in prehepatic portal hypertension, it is not known whether sodium retention is also a feature of this entity. The aim of this study in portal vein-constricted rats was to evaluate (a) whether sodium retention is a feature of prehepatic portal hypertension and (b) if sodium retention is present in this model, what its temporal relationship with peripheral vasodilatation might be. It was proposed that an understanding of the temporal interplay between peripheral vasodilatation and sodium retention could shed light on the current theories of sodium retention in portal hypertension. Rats were studied 1, 2, 3, and 4 days after partial portal vein ligation (n = 80) or sham operation (n = 63). Sodium retention was evaluated by changes in the size of the sodium space measured by the volume of distribution of 22Na. Systemic vascular resistance was calculated from mean arterial pressure (measured by arterial catheterization) and cardiac index (measured by thermodilution). A decrease in systemic vascular resistance was already observed on day 1 after constriction of the portal vein (4.2 +/- 0.2 vs. 5.2 +/- 6.1 mm Hg.min.mL-1.100 g; P less than 0.01). However, an expansion of the sodium space, which indicates sodium retention, was not observed until day 2 after induction of portal hypertension (37.1 +/- 0.8 vs. 32.6 +/- 0.7 mL.100 g-1; P less than 0.01). Therefore, sodium retention should be considered along with peripheral vasodilatation among the characteristic features of prehepatic portal hypertension. Because the reduction in systemic vascular resistance preceded the expansion of the sodium space by at least 24 hours, the finding of this study indicates that sodium retention follows peripheral vasodilatation.

Animals↗

PubMed1986

Solute and mobile phase contributions to retention in hydrophobic interaction chromatography of proteins.

Hydrophobic interaction chromatography utilizes high salt concentrations mobile phases to induce an interaction between a weakly hydrophobic matrix and exposed hydrophobic amino acids of a native protein. Proteins with a hydrophilic exterior have shorter retention times on a hydrophobic interaction column than do proteins with more hydrophobic exteriors. To examine the effect of amino acid substitutions on protein retention, lysozyme isolated from related bird species was chromatographed on a hydrophobic interaction column at increasing ammonium sulfate concentrations. Chromatographic retention deviated only when amino acid substitutions occurred on the surface of lysozyme opposite the catalytic cleft. This area may constitute a contact surface area and extends from Residue 41 to 102 and from 75 to the alpha-helical region starting with Residue 89. Retention was analyzed by plotting log k' versus the molal concentration of ammonium sulfate. The slope did not deviate significantly for each of the bird lysozymes, indicating a similar contact surface area. However, there was significant deviation in the intercept of each of the lysozyme lines, which probably reflects the strength of the hydrophobic interaction. The intercept increased as the lysozyme became more hydrophobic. Hydrophilic amino acid substitutions affected retention as much as hydrophobic ones. The ionization state of histidine residues within the contact area between lysozyme and the column surface also influenced retention. An uncharged histidine residue increased retention, while a decrease in retention was seen with a charged histidine residue. The amino acid substitutions did not appear to affect the size of the hydrophobic contact surface area, but rather the strength of the hydrophobic interaction. The effect of salt composition on protein retention indicated that factors other than surface tension could influence retention. These factors appear to include protein hydration and specific interactions between the protein and the salt ions. Of these, the latter may or may not result in an alteration in protein structure. The magnitude of the effect of salt composition was found to be dependent upon the protein.

Amino Acid Sequence↗

PubMed2006

Opposite effects of a single versus repeated doses of gabapentin on retention performance of an inhibitory avoidance response in mice.

CF-1 male mice were trained in an inhibitory avoidance (IA) task. A single gabapentin (GBP) administration (50mg/kg, ip) immediately after training enhanced retention performance when mice were tested 8 days after training. On the contrary, when the same dose of the anticonvulsant drug was given twice a day for 7 days (repeated treatment), a significant impairment on retention performance 12h after the last injection of GBP was observed. When the retention test was delayed 7 days after the end of the repeated treatment, the retention performance was not significant different from the control group, whereas if the retention test was delayed 14 days, retention performance was higher than control group but similar to that observed when GBP was administered once immediately after training. The impairment on retention performance was correlated with a significant decrease in the high affinity choline uptake in the hippocampus at the end of the retention test. The pretest administration of the direct muscarinic cholinergic agonist oxotremorine (50 microg/kg, ip) reversed the impairment on retention performance. This reversion was prevented by the muscarinic cholinergic antagonist scopolamine (0.5 mg/kg, ip). Taken together, these results suggest that the impairment on retention performance of an IA task in mice induced by repeated administration of GBP affected memory retrieval but not memory consolidation and that this impairment may be attributable to a reduction on central cholinergic activity.

Amines↗

PubMed2002

Retention characteristics of an immobilized artificial membrane column in reversed-phase liquid chromatography.

Retention for a varied group of compounds on an immobilized artificial membrane column (IAM PC DD2) with a methanol-water mobile phase is shown to fit a second-order model for the retention factor (log k) as a function of the volume fraction of organic solvent. The numerical value of the intercept obtained by linear extrapolation to zero organic solvent (log k(w)) is shown to depend on the range of mobile phase composition used for the extrapolation. Each series of intercepts so obtained represents a different hypothetical distribution system as identified by the system constants of the solvation parameter model. Although a linear model is a poor fit for isocratic retention data, the linear solvent strength gradient model provides a reasonable estimate of isocratic retention factor values that are (slightly) larger than experimental values, but provide the same chemical information for the system. These preliminary results suggest that gradient elution may prove to be a rapid and useful method for creating system maps for column characterization and method development. In this work a system map is provided for methanol-water compositions from 0 to 60% (v/v) methanol and additional system constants for acetonitrile-water compositions containing 20 and 30% (v/v) acetonitrile. It is shown that the main factors contributing to retention on the IAM PC DD2 column are favorable cavity formation and dispersion interactions, electron lone pair interactions and the hydrogen-bond basicity of the sorbent. The latter feature more than any other distinguishes the IAM column from conventional chemically bonded phases. Interactions of a dipole-type (weakly) and inability to compete with the mobile phase as a hydrogen-bond acid reduce retention. A comparison of system constant ratios is used to demonstrate that the retention properties of the IAM column are not easily duplicated by conventional chemically bonded phases. The retention characteristics of the IAM column, however, are strongly correlated with the retention properties of pseudostationary phases used for micellar electrokinetic chromatography, which provide a suitable alternative to IAM columns for physical property estimations. By the same comparative method it is shown that retention on the IAM column possesses some similarity to biomembrane absorption processes, allowing suitable correlation models to be developed for the estimation of certain biopartitioning properties.

Chromatography, Liquid↗

PubMed2003

Comparison of retentive systems for composites used as alternatives to porcelain in fixed partial dentures.

STATEMENT OF PROBLEM: The bond strength between framework metals and composites, used as alternatives to porcelain, requires further study because adhesive failures can promote microleakage, discoloration, and stains in composites. PURPOSE: The aim of this in vitro study was to analyze and compare the tensile strength between the base metal Ni-Cr alloys: (Wirocer and Wiron 99) and 2 composites (Artglass and Solidex) with 2 types of mechanical retention (0.4-mm and 0.6-mm beads); 2 types of chemical treatment (Siloc system and Metal Photo Primer system) and the combination of both treatments on a metal framework; to verify whether these composite systems were strong enough to be used as alternatives to porcelain. MATERIAL AND METHODS: A total of 144 specimens, cylindrical metal rods (3 mm diameter x 60 mm length), were cast in Ni-Cr alloy (Wiron 99 or Wirocer), divided into 6 equal groups corresponding to 6 types of retention: airborne particle abrasion/control (A), chemical (C), mechanical with 0.4-mm (M4) and 0.6-mm beads (M6), and chemical/mechanical with 0.4-mm (CM4) and 0.6-mm beads (CM6). Composite rings formed around the rods (6.0 mm diameter X 2.0 mm thickness) of Artglass or Solidex were light polymerized in the UniXS unit (wavelength range of 320-520 nm for 540s) according to the manufacturer's specifications. Specimens were invested, and their tensile strength was measured at fracture with an EMIC-MEM 2000 universal testing machine at a crosshead speed of 2.0 mm/min and 500 kgf load cell. Statistical analysis was carried out with analysis of variance and Tukey's test at significance level P=.01. RESULTS: The highest mean retention values were recorded for groups CM6 (63.57 MPa) and M6 (63.05 MPa). The lowest mean retention values were recorded for groups A (30.63 MPa) and C (25.07 MPa). No significant difference was found regarding the alloys used in this study (P<.01). There was a significant difference in shear strength (P<.01) between Solidex (52.33 MPa) and Artglass (43.18 MPa). CONCLUSION: Within the limitations of this study, mechanical retention with 0.6-mm beads and chemical/mechanical retention with 0.6-mm beads increased the metal-composite tensile bond strength. No significant difference was found between these 2 retention systems. Chemical and airborne particle abrasion/control retentions were statistically weaker than the other types of retention tested. The retention means corresponding to the commercial-grade Ni-Cr alloys used were statistically different. The composite Solidex showed a tensile strength mean statistically higher than Artglass. All values observed were higher than that recommended for metal-ceramic dental restorative systems (25 MPa-ISO 9693).

Analysis of Variance↗

PubMed1997

The pathophysiological mechanism of fluid retention in advanced cancer patients treated with docetaxel, but not receiving corticosteroid comedication.

AIMS: Fluid retention is a phenomenon associated with taxoids. The principal objective of this study was to investigate the pathophysiological mechanism of docetaxel-induced fluid retention in advanced cancer patients. METHODS: Docetaxel was administered as a 1 h intravenous infusion every 3 weeks, for at least 4-6 consecutive cycles, to patients with advanced breast (n = 21) or ovarian (n = 3) carcinoma, who had received previous chemotherapy, 21 for advanced disease. Phase II clinical trials have shown that 5 day corticosteroid comedication, starting 1 day before docetaxel infusion, significantly reduces the incidence and severity of fluid retention. This prophylactic corticosteroid regimen is currently recommended for patients receiving docetaxel but was not permitted in this study because of its possible interference with the underlying pathophysiology of the fluid retention. RESULTS: Fluid retention occurred in 21 of the 24 patients but was mainly mild to moderate, with only five patients experiencing severe fluid retention. Eighteen patients received symptomatic flavonoid treatment, commonly prescribed after the last cycle. Specific investigations for fluid retention confirmed a relationship between cumulative docetaxel dose and development of fluid retention. Capillary filtration test analysis showed a two-step process for fluid retention generation, with progressive congestion of the interstitial space by proteins and water starting between the second and the fourth cycle, followed by insufficient lymphatic drainage. CONCLUSIONS: A vascular protector such as micronized diosmine hesperidine with recommended corticosteroid premedication and benzopyrones may be useful in preventing and treating docetaxel-induced fluid retention.

Adenocarcinoma↗

PubMed1982

The measurement of liquid and solid digesta retention in ruminants, equines and rabbits given timothy (Phleum pratense) hay.

1. Digesta passage and retention were measured in heifers, sheep, goats, equines and rabbits of varying body-weights when given timothy (Phleum pratense) hay. 2. Two passage markers were compared, cobalt (III) ethylene diamine tetraacetate (CoEDTA) and chromiummordanted timothy fibre for liquid and solid phase respectively. Both markers were injected into the rumen of the ruminants and into the caecum of the equines and rabbits. 3. In ruminants, two different sets of rate constants (k1 and k2) were derived from a two-pool model for marker passage, using a graphical approach and a computer-based non-linear least-squares curve-fitting technique. 4. Retention times, due to unidirectional flow through the gastrointestinal tract (transit time) and due to pool effects (mean retention time, MRT), were calculated. 5. Curve fitting was only successful for the excretion of liquids in ruminants. The two-pool model was not applicable to the passage of solids. 6. Apparent retention of liquid was always shorter than for solids in all species, except in rabbits. However, absorption of CoEDTA was too large in the rabbits to determine liquid retention accurately. Times for first appearance of the two markers were similar within animal groups. 7. MRT values were lowest in the rabbit, intermediate in equines and high in the ruminants. The MRT values (h) of solids and liquids respectively were: large heifers 65, 18; small heifers 48, 20; goats 41, 28; sheep 57, 26; equines 23, 18; rabbits 5.3, not determined. 8. Liquid retention seemed to decrease somewhat with increasing body-weight in the ruminants. Solids retention decreased with decreasing body-weight in the ruminants, but sheep had longer retention times than goats of similar size. Equines exhibited large individual variation in retention of the liquid or solid markers, seemingly unrelated to size. No effect of size was seen in the retention of solids in the rabbits.

Animal Feed↗

PubMed1993

Membrane protein retention in the yeast Golgi apparatus: dipeptidyl aminopeptidase A is retained by a cytoplasmic signal containing aromatic residues.

The mechanism by which yeast dipeptidyl aminopeptidase (DPAP) A, type II integral membrane protein, is retained in the late Golgi apparatus has been investigated. Prior work demonstrated that the 118-amino acid cytoplasmic domain is both necessary and sufficient for Golgi retention and that mutant or overexpressed DPAP A no longer retained in the Golgi was delivered directly to the vacuolar membrane (Roberts, C. J., S. F. Nothwehr, and T. H. Stevens. 1992. J. Cell Biol. 119:69-83). Replacement of the DPAP A transmembrane domain with a synthetic hydrophobic sequence did not affect either Golgi retention of DPAP A or vacuolar delivery of the retention-defective form of DPAP A. These results indicate that the DPAP A transmembrane domain is not involved in either Golgi retention or targeting of this membrane protein. A detailed mutational analysis of the cytoplasmic domain of DPAP A indicated that the most important elements for retention were within the eight residue stretch 85-92. A 10-amino acid region from DPAP A (81-90) was sufficient for Golgi retention of alkaline phosphatase, a type II vacuolar membrane protein. Detailed mutational analysis within this 10-amino acid sufficient region demonstrated that a Phe-X-Phe-X-Asp motif was absolutely required for efficient retention. The efficiency of Golgi retention via the DPAP A signal could be diminished by overexpression of wild type but not retention-defective versions of Kex2p, another late Golgi membrane protein, suggesting that multiple Golgi membrane proteins may be retained by a common machinery. These results imply a role for a cytoplasmic signal involving aromatic residues in retention of late Golgi membrane proteins in the yeast Saccharomyces cerevisiae.

Amino Acid Sequence↗

PubMed1996

Efficiency of lysine or threonine retention in growing rats fed diets limiting in either lysine or threonine.

Over a 21-d experiment, the efficiency of lysine and threonine retention was determined in 80 male Sprague-Dawley rats (65.9 +/- 0.3 g, means +/- SE) fed purified diets containing an amino acid mix limiting in either lysine or threonine. With additional increments of the first limiting amino acid, lysine concentration in total body protein (g/16 g N) increased (P < 0.01) in rats fed lysine-limiting diets but, when fed threonine-limiting diets, lysine concentration in body protein first increased and then decreased (P < 0.01). As increments of the first limiting amino acid were added, the threonine concentration in total body protein increased then decreased when both lysine- (P < 0.01) and threonine- (P < 0.06) limiting diets were fed. Lysine and threonine retention were calculated based on comparative slaughter. Sixteen rats were killed on d 0 to estimate the grams of amino acid in the body. Retention responses were analyzed using a logistic equation in which lysine or threonine intake was used to predict retention. The maximum marginal efficiency (dr/dI, retention/intake) was observed at <40% of maximum retention. For lysine retention, it was 81% when lysine was limiting and 70% when threonine was limiting. For threonine retention, it was 58% when threonine was limiting and 49% when lysine was limiting. The maximum cumulative efficiency (retention adjusted for maintenance relative to cumulative intake) for lysine retention was 62% when lysine was limiting or 58% when threonine was limiting. For threonine retention, it was 51% when threonine was limiting and 35% when lysine was limiting. Thus, amino acid concentration in body protein is not constant, and amino acids are used with higher efficiency when first limiting.

Amino Acids↗

PubMed1979

Retention in glass bead columns as a measure of leucocyte adhesiveness. II. Influence of platelets and erythrocytes.

The influence of platelets and erythrocytes on the retention of leucocytes in glass bead columns was studied. Leucocyte retention increased when platelet retention was stimulated by the presence of erythrocytes. In the presence of only a few erythrocytes, platelet retention was low, and platelets did not influence leucocyte retention. When only a small number of platelets was present, erythrocytes inhibited leucocyte retention. The platelet-dependent leucocyte retention increased as the volume passed through the columns was increased. However, the platelet-independent leucocyte retention did not change when the sample size was increased. In blood from patient with thrombocytopenia or defect in platelet function and in normal blood treated with inhibitor of platelet adhesion, neutrophil retention was reduced. However, erythrocyte-free leucocyte suspensions from these cases showed normal leucocyte retention. Thus, experiments with whole blood may serve as a model for the study of platelet-leucocyte interaction. However, for the study of leucocyte adhesiveness per se, isolated leucocytes seem more suitable than whole blood.

Adult↗

PubMed2001

Renal cortical retention on delayed CT and nephropathy following transcatheter arterial chemoembolisation.

The aim of this study was to examine the relationship between renal cortical retention on delayed CT and contrast medium-associated and/or transarterial chemoembolisation (TACE)-associated nephropathy following TACE. The authors reviewed the findings on 180 treatments in 121 patients with normal serum creatinine levels who underwent TACE for liver tumours. Nephropathy was defined as an increase in the creatinine level of greater than 0.5 mg x dl(-1) (44 micromol x l(-1)) and greater than 25% on days 1, 3, 7 or 14 post TACE. Renal cortical retention was recognized when CT values for the renal cortex showed either mild renal cortical retention (CT value >50) or severe renal cortical retention (CT value >100). There was evidence of renal cortical retention in 81 (45%) cases and of nephropathy in 11 (6%) cases. Only 2% of patients without renal cortical retention showed nephropathy, whereas 11% of those with renal cortical retention showed nephropathy (p=0.02). Stepwise selection using a multivariate logistic regression model showed renal cortical retention and gender to be significant factors for nephropathy following TACE. In conclusion, renal cortical retention is a useful predicator for nephropathy following TACE. Delayed CT could be used not only for assessment of lipiodol retention but also for predicting nephropathy.

Adult↗

PubMed1999

Retention of young general practitioners entering the NHS from 1991-1992.

BACKGROUND: The supply of general practitioners (GPs) in the National Health Service (NHS) is dynamic and there are fears that there will be an inadequate number of doctors to meet the needs of the NHS. There are particular concerns about changes in the career trajectory of young GPs and what they mean for overall supply. AIM: To identify predictors of retention among young, new entrant GPs entering the NHS between 1 October 1991 and 1 October 1992. METHOD: Two-year retention rates of young (35 years of age or less) new entrant GPs have been modelled using a multilevel logit model. Retention is defined as young, new entrant GPs remaining in their initial health authority for two years or more. RESULTS: Two hundred and fifty-two (13.0%) members of the study group left general practice within two years of entry (i.e. were not retained). Sex (females had lower retention [95% CI = 0.43-0.75]), practice size (young GPs in larger practices had higher retention [95% CI = 1.10-1.29]), and belonging to a practice in one of 16 Greater London Health Authorities (which had lower retention [95% CI = 0.39-0.82]) were identified as major predictors of retention. Deprivation, measured at the individual GP patient list level, had a very slight association with retention (P = 0.097; 95% CI = 1.00-1.02). Deprivation measured at the health authority level (95% CI = 0.99-1.01) was not found to be a statistically significant predictor of retention (P = 0.83). CONCLUSION: None of the statistically significant predictors of retention suggest any policy panacea to end this phenomenon. The challenge for policy is to learn to deal with the dynamic nature of the GP workforce with a non-crisis mentality.

Adult↗

PubMed2002

Long-term stability of orthodontic treatment out of retention.

OBJECTIVE: To investigate the correlative factors influencing the stability of orthodontic treatment out of retention. METHODS: Pre-treatment, post-treatment and 2 approximately 8 years out of retention study models of 74 cases with malocclusion were assessed by the PAR (Peer Assessment Rating) index. RESULTS: (1) Out of retention, the relapse rate was 13.01% in weighted PAR total scores and the relapse rate was 6.38%, 15.56%, 28.86%, 22.41% in alignment, overjet, overbite and transverse buccal occlusion respectively. (2) The rate of great improvement was decreased from 77.03% after treatment to 64.86% out of retention. The PAR score increased in 53 cases (71.62%), unchanged in 6 cases (8.11%) and reduced in 15 cases (20.27%) out of retention. (3) The weighted total scores in the Begg appliance were higher than that in Edgewise out of retention (P < 0.05). (4) The alignment and PAR total scores out of retention were higher in class II malocclusion than in class I malocclusion (P < 0.05). (5) The weighted PAR total scores post-retention were higher in unilateral extraction than in other groups (P < 0.01). CONCLUSIONS: (1) There was a trend that teeth relapsed to original position out of retention. The relapse rate was greater in alignment, overjet, overbite and transverse buccal occlusion. (2) The stability out of retention was not related to patient's age and sex, but was related to the types of appliance, malocclusion and extraction.

Adolescent↗

PubMed1991

[The thermographic observation of the relationship between the retention of acupuncture needles and the effect of nose temperatures].

This is an observation of the relationship between the retention of acupuncture needles and its effect on nose temperature in seventy-four patients with facial nerve paralysis. The patients were divided into five groups according to the period of retention of needles: no retention, retention for ten, twenty, thirty and fourty minutes. Every group consisted twenty cases. The results showed that (a) the nose temperature lowered after acupuncture immediately; (b) then it rose and reached to the maximum at twenty minutes after acupuncture, then lowered again; (c) for the group of no retention and retention for ten and twenty minutes, the temperature rose again during thirty to fourty minutes after acupuncture, for the group of retention for thirty or fourty minutes, however, without these phenomena; (d) the general tendency was that the change of temperature was bigger but lasting for shorter period in the groups of retention for longer time than that in the groups of retention for shorter time. These results verified that some theories in ancient books about the retention of acupuncture needles are scientific.

Acupuncture Therapy↗

PubMed1994

Predictors of early grade retention among children in the United States.

BACKGROUND: Despite increasing concerns regarding school readiness, little is known about child health correlates of early school failure among the general child population. The results of this study, conducted to investigate health and social factors associated with early grade retention in a nationally representative sample of children in the United States, are reported here. DESIGN: Analyses of data derived from interviews with parents of 9996 children ages 7 to 17 years who participated in the Child Health Supplement to the 1988 National Health Interview Survey. MAIN OUTCOME MEASURES: History of repeating kindergarten or first grade. RESULTS: Nationally, 7.6% of children repeated kindergarten or first grade. In a logistic regression model, factors independently associated with increased risk of grade retention were: poverty [Odds Ratio (OR) 1.7, 95% confidence interval (CI) 1.4, 2.1], male gender (OR 1.5, CI 1.3, 1.9), low maternal education (OR 1.4, CI 1.1, 1.8); deafness (OR 1.9, CI 1.4, 2.6), speech defects (OR 1.7, CI 1.1, 2.6), low birth weight (OR 1.6, CI 1.2, 2.2), enuresis (OR 1.6, CI 1.1, 2.2), and exposure to household smoking (OR 1.4, CI 1.1, 1.7). High maternal education (OR 0.6 CI 0.4, 0.9) and residence with both biological parents at age 6 years (OR 0.7, CI 0.6, 0.9) were independently associated with a decreased risk of retention. Recurrent otitis media, black race, and low maternal age, although associated with early grade retention in bivariate analyses, were not independently associated with grade retention in a model that controls for these other factors and for the age cohort of the child. Although omitted from the above predictive model because of uncertainty about its temporal relation to early grade retention in this dataset, behavior problems at the time of interview have a strong independent association (OR 1.9, CI 1.5, 2.5) with prior early retention. CONCLUSIONS: This is the first study that uses national data to investigate how health and social factors individually and collectively contribute to early grade retention. It demonstrates that early retention is common, that a number of extremely common child health problems are independently associated with it, and that the magnitude of the heightened risk associated with these problems is similar to that of many of the well-recognized and difficult to change family and social risk factors for early retention. The successful implementations of Pub L 99-457 (The Education for All Handicapped Children Act Amendments of 1986) services in communities nationwide, and the improvement in the educational performance of large numbers of children will be facilitated by pediatricians' advocacy and surveillance for problems that place children at risk for educational failure, and by effective referral to and collaboration with nonpediatric child and family services.

Adolescent↗

PubMed2002

Antibody to amyloid beta protein alleviates impaired acquisition, retention, and memory processing in SAMP8 mice.

SAMP8 (senescence-accelerated mouse, P8 strain) mice overproduce amyloid precursor protein and beta-amyloid and have learning and memory deficits. Preliminary data have indicated that overproduction of beta-amyloid plays a role in the pathogenesis of acquisition and retention deficits in SAMP8 mice. In the studies reported here, the authors examined the effects of polyclonal and monoclonal antibodies to beta-amyloid on acquisition and retention in an aversive T-maze testing paradigm when injected intracerebroventricularly (ICV) into 12-month SAMP8/TaJF mice. Both the polyclonal and monoclonal antibodies improved acquisition and retention when injected ICV 1 to 14 days prior to acquisition testing. Injection of all three antibodies intrahippocampally immediately following training improved retention on the T-maze when mice were tested 7 days later. The authors next studied the effect of monoclonal beta-amyloid antibody injected 48 h prior to training on the effect on retention in the T-maze of drugs modulating classical neurotransmitters. Arecoline and glutamate were injected directly into the hippocampus, and ketanserin, methiothepen, bicuculline, and OH-saclofen were injected into the septum. Previously, the authors have found that the doses of these drugs required to improve retention are markedly altered in 12-month SAMP8/TkJF mice compared to 4-month P8 mice. In these studies, it was demonstrated that antibody to beta-amyloid resulted in these drugs improving retention at doses that improved memory in 4-month SAMP8/TaJF mice. Based on these findings, we conclude that beta-amyloid overproduction is at least in part responsible for the acquisition and memory deficits in 12-month-old SAMP8/TaJF mice. Antibody to beta-amyloid restores the retention response to neurotransmitter manipulation to that seen in 4-month-old mice. beta-amyloid appears to play a key role in the loss of acquisition and retention seen in SAMP8/TaJF mice.

Amyloid beta-Peptides↗

PubMed2004

Pessary reduction and postoperative cure of retention in women with anterior vaginal wall prolapse.

This study aimed to determine whether preoperative pessary reduction of anterior vaginal wall prolapse in patients with elevated postvoid residual (PVR) volumes relieves urinary retention, and if reconstructive pelvic surgery in these patients cures urinary retention. The records of all women with symptomatic anterior vaginal wall and urinary retention (PVR >or=100 cc) who underwent evaluation and surgical repair of the anterior vaginal wall at our institution between 1996 and 1999 were retrospectively reviewed. All patients underwent a detailed urogynecologic and urodynamic evaluation and had a pessary trial prior to surgery. Cure of urinary retention was defined as PVR <100 cc at 3 months postoperatively. Sensitivity, specificity, positive and negative predictive values for pessary reduction testing were calculated. Twenty-four patients met the inclusion criteria. Two patients (8%) had stage 2, eleven (46%) stage 3, and eleven (46%) stage 4 anterior vaginal wall prolapse. Preoperatively, the use of pessary was associated with relief of urinary retention in 75% patients. In predicting postoperative cure of urinary retention, pessary testing had a sensitivity of 89%, specificity of 80%, positive predictive value of 94%, and negative predictive value of 67%. Nineteen of 24 patients had a PVR <100 cc postoperatively, indicating a 79% cure rate for urinary retention. In women with symptomatic anterior vaginal wall prolapse and urinary retention, use of a pessary is associated with relief of retention in the majority of patients. Furthermore, pessary reduction testing has good sensitivity, specificity, and positive predictive value for postoperative voiding function.

Adult↗