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PubMed1994

Insidious urinary retention after vaginal delivery: prevalence and symptoms at follow-up in a population-based study.

The purpose of this study was to investigate the prevalence of postpartum urinary retention in women after vaginal delivery and to determine whether parturients with retention develop voiding problems later. During a 3-month period, all parturients in the catchment area of the University Hospital, Lund, were investigated 3 days after delivery, residual volume being measured by ultrasonography. All those with postpartal retention were contacted 4 years after delivery, when they were reexamined by ultrasonography and asked to fill in a questionnaire regarding urinary problems. In all, 539 women were scanned post partum, and 8 (1.5%) had a residual volume exceeding 150 ml (range 156-320 ml). Retention was more common among primiparae after instrumental delivery or epidural analgesia. The symptoms were normalized spontaneously within a few days in all cases. At follow-up 4 years later, the prevalence of urinary symptoms was not higher than that in the general population. Ultrasonography to detect urinary retention does not seem to have any place in the normal postpartal care. However, extended supervision may be appropriate in parturients receiving epidural analgesia or in those submitted to instrumental deliveries.

Analgesia, Epidural↗
PubMed1992

Retention of trained performance in consistent mapping search after extended delay.

We examined the retention of performance in memory, visual, and hybrid memory/visual search after subjects received extensive consistent mapping (CM) practice. In the first two experiments we examined retention of detection performance in memory scanning (Experiment 1) and in visual search (Experiment 2) approximately one month after training. In the third experiment we examined performance 1, 30, 90, 180, and 365 days following training on pure visual and hybrid memory/visual semantic-category search tasks. We examined retention at intervals up to one year after practice as a function of amount of CM practice. In addition, we assessed the degree of category activation (performance on untrained words from the trained categories) at each retention interval. Across experiments, we found no decay in CM trained memory search and minimal decay in pure visual search. Significant decline in CM performance was largely attributable to performance in the hybrid memory/visual search conditions. These data reconcile previously equivocal retention results for CM trained search performance.

Adult↗
PubMed2005

Strategies for retaining study participants in behavioral intervention trials: retention experiences of the NIH Behavior Change Consortium.

Failing to retain an adequate number of study participants in behavioral intervention trials poses a threat to interpretation of study results and its external validity. This qualitative investigation describes the retention strategies promoted by the recruitment and retention committee of the Behavior Change Consortium, a group of 15 university-based sites funded by the National Institutes of Health to implement studies targeted toward disease prevention through behavior change. During biannual meetings, focus groups were conducted with all sites to determine barriers encountered in retaining study participants and strategies employed to address these barriers. All of the retention strategies reported were combined into 8 thematic retention categories. Those categories perceived to be most effective for retaining study participants were summarized and consistencies noted among site populations across the life course (e.g., older adults, adults, children, and adolescents). Further, possible discrepancies between site populations of varying health statuses are discussed, and an ecological framework is proposed for use in future investigations on retention.

Health Behavior↗
PubMed2004

Retention of basic science knowledge: a comparison between body system-based and clinical presentation curricula.

BACKGROUND: When the University of Calgary implemented the clinical presentation (CP) curriculum in 1994, it was prospectively decided to administer the National Board of Medical Examiner's Comprehensive Basic Science Exam (CBSE) as a measure of students' basic science knowledge retention. PURPOSE: The exam performance from 2 classes (1995, 1996) of the previous system-based (SB) curriculum was compared to exam performance of 2 classes (2000, 2002) of the CP curriculum. METHODS: Data analyses employed 2 statistical models (covariate multiple linear regression and hierarchical mixed effects), and effect sizes were computed. RESULTS: Differences between CBSE mean scores produced by students from the SB and CP curricula showed a curricular effect on students' retention of basic science knowledge. However, preexisting differences between groups were found to be in the small-to-medium range. CONCLUSION: Evidence supporting the potential of schemes within a CP curriculum and their relation to basic science knowledge retention was observed. Effect size for the CP curriculum on students' retention of basic science knowledge was substantial; however, a notable part of that difference can be accounted for by extraneous and confounding factors. Further research utilizing more rigorous designs to investigate the relation between schemes and basic science retention is warranted.

Alberta↗
PubMed1998

Involvement of hippocampal NMDA receptors in retention of shuttle avoidance conditioning in rats.

The purpose of this research was to evaluate the role of hippocampal N-methyl-D-aspartate (NMDA) receptors in acquisition and consolidation of memory during shuttle avoidance conditioning in rats. Adult male Wistar rats were surgically implanted with cannulae aimed at the CA1 area of the dorsal hippocampus. After recovery from surgery, animals were trained and tested in a shuttle avoidance apparatus (30 trials, 0.5-mA footshock, 24-h training-test interval). Immediately before or immediately after training, animals received a bilateral intrahippocampal 0.5-microliter infusion containing 5.0 microgram of the NMDA competitive receptor antagonist aminophosphonopentanoic acid (AP5) or vehicle (phosphate-buffered saline, pH 7.4). Infusion duration was 2 min per side. Pre-training infusion of AP5 impaired retention test performance (mean +/- SEM number of conditioned responses (CRs) during retention test session was 16.47 +/- 1.78 in the vehicle group and 9.93 +/- 1.59 in the AP5 group; P < 0.05). Post-training infusion of AP5 did not affect retention (mean +/- SEM number of conditioned responses during retention test session was 18.46 +/- 1.94 in the vehicle group and 20.42 +/- 2.38 in the AP5 group; P > 0.10). This impairment could not be attributed to an effect on acquisition, motor activity or footshock sensitivity since AP5 affected neither training session performance measured by the number of CRs nor the number of intertrial crossings during the training session. These data suggest that NMDA receptors in the hippocampus are critical for retention of shuttle avoidance conditioning, in agreement with previous evidence showing a role of NMDA receptors in fear memory.

2-Amino-5-phosphonovalerate↗
PubMed1989

[Studies on the retentive force of clasps. 1. An effect of the material and technician].

Wire clasps and cast clasps are the most common retainers for removable partial dentures. The purpose of this study was to investigate the differences in the material and the variation among individual technicians in the retentive force of both clasps. The clasps were made in accord with the clinical method for experimental metallic model of the left mandibular second premolar and the retentive force of each clasp was measured by a pull-out test. The results were as follows: 1. Both types of clasp showed a large variation in the retentive force among the technicians, but no particular tendency was observed in the differences between wire and cast clasps. 2. There was no significant difference between the two types of clasp in the retentive force. 3. Due to the differences in individual technical skills, it seems to be difficult to make wire clasps with a standardized retentive force.

Denture Design↗
PubMed1984

Retention of complete maxillary dentures related to soft tissue function.

The influence of free tongue, lip, and cheek function on the retention of complete maxillary dentures was investigated for five experienced denture wearers. Test dentures were designed with full palatal coverage and functionally determined filling in of the vestibular sulcus. The front teeth were arranged primarily to meet cosmetic demands--that is, anterior to the top of the residual alveolar ridge. Retention was measured as resistance to dislodgement-provoking loads applied vertically to the incisive edge of the central incisors, using a miniature bite force recorder. All the participants were able to load their front teeth with 35 N or more without loss of retention. None of them experienced denture dislodgement provided the tongue, lips, and cheeks wee allowed to act freely. If the peripheral soft tissues were separated from the vestibular denture flange, no obvious effect on denture retention could be detected. Physically preventing the tongue from pressing against the posterior part of the denture reduced the retention significantly. Measurements of anterior loads tolerated after stepwise reductions of the denture extension indicated that the tongue acted primarily by pressure against the tuber regions. Tongue pressure against the central parts of the palate and lip or cheek pressure against the vestibular flange seemed to be of less importance.

Aged↗
PubMed1986

Effects on retention of reducing the palatal coverage of complete maxillary dentures.

Twenty patients with complete dentures in both jaws gave up their maxillary ones for experimental purposes for 4 weeks while new dentures were made. The experimental dentures were reduced palatally to a new U-shaped border situated approximately 10 mm from the dental arch. Denture retention, defined as the ability of a denture to remain seated on the supporting tissues under various conditions, was measured as resistance towards cranially directed tilting loads, using a miniature bite force recorder. Dislodgement-provoking loads were applied to the first bicuspid on both sides and to the central incisors. The retention measurements were performed before and immediately after reduction of the palatal coverage and, finally, after 4 weeks. Interview questions were posed concerning the subjects' experience of denture retention and some other aspects of oral comfort. The interviews were carried out before reduction of the palatal coverage and after 2 and 4 weeks. The results of the experimental dislodgement tests suggested that the ability to withstand tilting loads was insignificantly altered by reduction of the palatal coverage. This finding was in agreement with responses indicating that retention during meals remained unchanged. However, several individuals reported that denture retention between meals was impaired. Three denture wearers reported that reduction of the palatal coverage influenced their sense of taste positively, and one reported that an occasional gagging tendency had disappeared. At the end of the experiment the participants were given the choice of a new conventional denture or a new denture without palatal coverage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1997

Need probability affects retention: a direct demonstration.

Recent memory theory has emphasized the concept of need probability--that is, the probability that a given piece of learned information will be tested at some point in the future. It has been proposed that, in real-world situations, need probability declines over time and that the memory-loss rate is calibrated to match the progressive reduction in need probability (J.R. Anderson & Schooler, 1991). The present experiments were designed to examine the influence of the slope of the need-probability curve on the slope of the retention curve. On each of several trials, subjects memorized a list of digits, then retained the digits in memory for 1, 2, 4, 8, or 16 sec. Some trials ended with a recall test; other trials ended with the message, "no test." In Experiment 1, the likelihood of encountering a memory test (i.e., the need probability) was made to either increase or decrease as the retention interval increased; in Experiment 2, need probability either was flat (invariant across retention intervals) or decreased as the retention interval increased. The results indicated that the shape of the need-probability curve influenced the slope of the retention curve (Experiment 1) and that the effect became larger as the experimental session progressed (Experiment 2). The findings support the notion that memory adapts to need probabilities and that the rate of forgetting is influenced by the slope of the need-probability curve. In addition, all of the forgetting curves approximated a power function, suggesting that need probability influences the slope but not the form of forgetting.

Educational Measurement↗
PubMed2005

Influence of fabrication techniques on retention force of fiber-reinforced composite posts.

The purpose of this study was to compare the retention force of FRC posts which were built up using direct and direct-indirect fabrication techniques with two fiber-reinforced core build-up systems (FibreKor and i-TFC). Posts were cemented in endodontically treated bovine single roots with resin cement using either direct or direct-indirect technique. Following which, the retention force of post-and-cores and fracture sites were examined. It was found that both the retention force and fracture site depended on the fabrication technique and resin cements. Post-and-cores built up with direct-indirect technique had greater retention force than those fabricated using direct technique. Fracture modes most frequently observed were adhesive failure at Resin/Dentin interface, a mixture of adhesive failures at Post/Resin and Resin/Dentin interfaces as well as cohesive failure of resin cements. Based on the results of this study, we concluded that when it comes to post-and-core build-up for endodontically treated tooth, the direct-indirect technique is more effective than the direct technique on the retention force of FRC posts.

Analysis of Variance↗
PubMed2001

Management of men with a first episode of acute urinary retention due to benign prostatic enlargement.

OBJECTIVE: To determine the effect of the existing management protocol of patients presenting with acute urinary retention due to benign prostatic enlargement on clinical efficacy and surgical practice. DESIGN: Prospective study. SETTING: The Urology Unit at the Teaching Hospital, Karapitiya, Galle. PATIENTS: 100 consecutive patients with a first episode of acute urinary retention due to a clinically benign enlarged prostate. MEASUREMENTS: Success of voiding urine after one week of treatment with an alpha adrenoceptor blocker (prazosin). Incidence of subsequent urinary retention during the follow up period of 6 months despite continuing treatment with the drug. RESULTS: Of the 94 patients who completed the follow up period of 6 months, 56 voided successfully after the initial trial without catheter at one week. However, 12 of them developed urinary retention during the follow up and required surgery. CONCLUSION: Treatment with an alpha adrenoceptor blocker followed by a single trial without catheter can avoid prostatic surgery in 40% of patients with acute urinary retention due to benign prostatic enlargement.

Adrenergic alpha-Antagonists↗
PubMed1987

[On the relation between prototype abstraction and exemplar retention in the memory of melodies].

This study examined the relation between prototype abstraction and exemplar retention by using memory of melodies. Acquisition lists of melodies were constructed by applying a set of transformation rules to a fixed prototype melody (cf. Welker, 1982). Immediately after the presentation of acquisition list, recognition task was performed. The recognition rating for prototype was used as the indicator of the prototype abstraction. The discriminability of old melodies from new melodies (d') was used as the indicator of exemplar retention. In Exp. 1 with 30 undergraduates as subjects, the transformational distance of acquisition list was varied and it was demonstrated that as the transformational distance decreased, prototype abstraction was facilitated but exemplar retention was not changed. In Exp. 2 with 90 undergraduates as subjects, the number of presentation of each melody and the kinds of melodies in acquisition list were varied. Results demonstrated that as the number of presentation of each melody increased and also as the kinds of melodies decreased, the exemplar retention improved but prototype abstraction was not changed. It was argued that the systems underlying the prototype abstraction and exemplar retention were functionally independent of each other.

Adult↗
PubMed1994

[Locus of the retention benefits of variable practice in the motor learning].

Shea and Kohl (1990) reported that acquisition practice with variations of the criterion task leads to better retention than practice on the criterion task alone. The purpose of this study was to determine the locus of this retention benefits. Experimental task was the speed reproduction task. Eighty undergraduate male students were randomly assigned to eight practice conditions differing in the activities performed during the intertrial intervals. All subjects were administered retention test immediately and twenty-four hours after the practice. Results indicated that the retention benefits demonstrated by subjects provided variable practice was produced by the contextual interference effect not by the formation of motor response schema. Results also suggested that both of reconstruction of action plan and elaborative processing resulted in the retention benefits.

Adolescent↗
PubMed1992

[A case of urinary retention due to tuberculous pyometra].

A rare case of urinary retention due to tuberculous pyometra is presented. A 70-year-old woman visited our hospital complaining of dysuria and pollakisuria on January 26, 1990. In spite of medication of cholinergic agents, urinary retention developed on April 6, 1990. Cystoscopy revealed elevation of the urethra and bladder neck. Physical examinations disclosed a child-head-sized tumor in the lower abdomen, which persisted following catheterization. Excretory urogram showed a large retrovesical mass. Chain urethrocystogram revealed anterior dislocation of the bladder neck and the proximal portion of the urethra. CT scan and MRI demonstrated a fluid-filled pelvic mass, which positioned above the vagina and compressed the urinary bladder anteriorly. Total hysterectomy was performed on August 6, 1990. Pathological diagnosis was tuberculous endometritis. Urinary symptoms disappeared immediately after the operation. Postoperative chain urethrocystography revealed complete cure of the dislocation of the bladder neck and urethra. We collected 34 cases of urinary retention due to gynecological disease in Japan, and 110 cases in English literature. Among the frequent diseases were retroverted gravid uterus, prolapse uteri, uterine leiomyomas, ovarian cyst, imperforated hymen and vaginal atresia. The mechanisms of urinary retention in gynecological disease are discussed. No case of urinary retention due to tuberculous pyometra was found in the literature.

Aged↗
PubMed2006

[Clinical study of acute urinary retention].

PURPOSE: Clinical study of acute urinary retention seen by this department. MATERIALS AND METHODS: Subjects were 206 cases seen during office hours and during after-hours emergency care by the department of Urology at the Kinki University Hospital for acute urinary retention for the 12-year-period from April 1993 to April 2005. RESULTS: By gender, the 206 cases of acute urinary retention included 175 men (85%) and 31 women (15%). The ratio of men to women was 5.6:1, with a markedly larger number of male cases. Ages of the 206 cases overall were distributed from 6 to 93 years old and the mean age was 66 years old. In male cases, the mean age was 69.6 years old while in female cases it was 46.3 years old. With regard to the cause, bladder outlet obstruction (BOO) accounted for 123 (70.3%) of the 175 male cases; benign prostatic hyperplasia (BPH) was noted in 92 cases and accounted for 52.6%of the total. Detrusor Weakness (DW) was noted in 35 cases (20%). DW was most prevalent in women, being noted in 20 cases (64.5%). With regard to treatment, in male cases surgery was performed for BOO in 69 (56%) of 123 cases; surgery was performed for BPH in 56 (60.8%) of 92 cases, drug therapy was used in 19 cases, and 3 cases were observed. In female cases, 10 cases were able to urinate on their own through treatment of the causative disorder. With regard to outcome, ultimately a total of 139 cases (67.5%), 125 men and 14 women, were able to urinate on their own. CONCLUSIONS: 1. 85% of acute urinary retention cases were men. Of these, 70% were caused by some form of BOO. DW due to a cause other than obstruction accounted for about 70% of the remaining 30%. 2. Overall, 70% of cases were able to urinate on their own after treatment while 30% required catheterization. 3. After the cause of BOO was eliminated, cases were likely to be able to urinate on their own; CIC (clean intermittent catheterization) was frequently used in treatment of causes other than BOO. 4.15% of acute urinary retention cases were women.

Acute Disease↗
PubMed1976

Differential distraction effects in short-term and long-term retention of pictures and words.

Picture and word triads were followed by single visual and acoustic distraction tasks and by both tasks in sequence. Short-term retention between and within modalities differed as a function of type of distraction. Individual subject-recall probabilities for each single distraction condition failed to predict performance in the sequential dual-distraction conditions, underestimating performance for words and overestimating performance for pictures. A final delayed recall showed a reversal among distraction conditions within each modality, such that the best short-term retention condition (visual distraction) was poorest in long-term retention. However, long-term retentions of pictures was superior to that of words across all distraction conditions and irrespective of level of short-term retention. The results were interpreted in terms of separate acoustic and visual processing systems and the level of individual item processing within each system as a function of the type of interference originally expected.

Attention↗
PubMed1976

Effects of scopolamine and methscopolamine on acquisition and retention of rat one-way shuttle box behavior and total brain acetylcholine.

The effects of scopolamine HBr (0.032 to 10.0 mg/kg), methscopolamine Br (1.0 and 10.0 mg/kg) and 0.36 mg/kg NaBr on acquisition and retention of one-way avoidance behavior and total brain acetylcholine (ACh) were studied in male albino rats. Compared to equimolar NaBr, scopolamine caused a dose-related impairment in acquisition of avoidance responding while methscopolamine did not. Retention of avoidance behavior in trained rats was also disrupted, but the detrimental effect was smaller and occurred only following large doses of scopolamine. The per cent escape behavior was not decreased by any of the treatments. It increased as avoidance was decreased. Scopolamine caused a dose-related increase in latency and avoidance and escape responding compared to equimolar NaBr. However, scopolamine increased the latency of avoidance at lower doses and to a greater degree than it increased the latency of escape. Escape latencies were significantly increased only at the largest dose (10 mg/kg). These dose-related effects of scopolamine were greater during acquisition than during retention. Small doses (0.032 mg/kg) shortened latency of avoidance during retention. Methscopolamine increased avoidance and escape latencies only at the largest dose (10 mg/kg). Scopolamine produced a dose-related decrease in brain ACh which correlated well with the per cent avoidance in acquisition (r = 0.95) and retention (r = 0.88) trials. It is concluded that a muscarinic cholinergic antagonist with central actions like scopolamine affects selective aspects of avoidance behavior in low doses, and that these changes are highly correlated with brain ACh levels.

Acetylcholine↗
PubMed1999

Corticotropin-releasing factor enhances brain-derived neurotrophic factor gene expression to facilitate memory retention in rats.

In the present study, we investigated the effects of corticotropin-releasing factor (CRF) injected into the dentate gyrus (DG) of the hippocampus on brain-derived neurotrophic factor (BDNF) mRNA expression and studied whether N-methyl-D-aspartate (NMDA) receptor mediates the effects of CRF on BDNF mRNA expression in the DG. Since both CRF and BDNF gene expressions are involved in memory processing in rats, we further investigated whether CRF facilitates memory retention through enhanced BDNF mRNA expression in the hippocampus. Effect of direct BDNF injection to the DG on retention performance in rats was also assessed. Results indicated that intra-DG CRF injection produced a dose-dependent (0.1 microg, 1.0 microg and 10 microg) increase in BDNF mRNA level, while intra-DG MK801 injection produced a dose-dependent (0.08 microg, 0.2 microg and 2.0 microg) decrease in BDNF mRNA expression in the DG. MK801, at a dose having no significant effect alone (0.08 microg), significantly antagonized the effect of CRF on BDNF mRNA expression. On the other hand, CRF (1.0 microg) consistently and markedly improved retention performance in rats in an inhibitory avoidance learning task. BDNF antisense oligonucleotide treatment, at a concentration which did not affect retention performance alone (0.5 mM), blocked the memory-enhancing effect of CRF. However, direct and chronic BDNF injection to the DG did not improve memory performance in rats. These results together suggest that at least one of the mechanisms responsible for the memory-facilitating effect of CRF is mediated through enhanced BDNF mRNA expression in the hippocampus. The lack of an effect of intra-DG BDNF injection on memory retention is also discussed.

Animals↗