Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures.

BACKGROUND: Hip fracture patients have a high risk of thrombo-embolic complications following surgical management. OBJECTIVES: To examine the effects of heparin (unfractionated (U), and low molecular weight (LMW) heparins), and physical methods (compression stockings, calf or foot pumps) for prevention of deep venous thrombosis (DVT) and pulmonary embolism after surgery for hip fracture in the elderly. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group specialised register (up to March 2002), MEDLINE (1966 to March 2002), EMBASE (1980 to March 2002), CINAHL (1982 to February week 4 2002), Current Contents (1993 week 26 to 2002 week 12), reference lists of published articles and contacted trialists and other workers in the field. Date of most recent search: March 2002. SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating the use of heparins and physical agents for prevention of DVT and pulmonary embolism in patients undergoing surgery for hip fracture. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed methodological quality and extracted data. Trials were grouped into five categories (heparin versus control, mechanical versus control, LMW heparin versus U heparin, heparin versus mechanical, and miscellaneous) and results pooled where possible. MAIN RESULTS: The 31 included trials involved at least 2958 predominantly female and elderly patients. Overall, trial quality was disappointing. Ten trials involving 826 patients which compared U heparin with control, and five trials of 373 patients which compared LMW heparin with control, showed a reduction in the incidence of lower limb DVT (124/474 (26%) versus 219/519 (42%); relative risk (RR) 0.60; 95% confidence interval (CI) 0.50 to 0.71). There were insufficient data to confirm the efficacy of either agent in the prevention of pulmonary embolism. There was no statistically significant difference in overall mortality (42/356 (12%) versus 38/374 (10%); RR 1.16; 95%CI 0.77 to 1.74). Data were inadequate for all other outcomes including wound complications. There is insufficient evidence from five trials, involving 644 patients, to establish if LMW heparin was superior to U heparin. Most trials evaluating heparins had methodological defects. Five trials, involving 487 patients, testing mechanical pumping devices were also methodologically flawed, and so pooled results need to be viewed cautiously. Mechanical pumping devices may protect against DVT (16/221 (7%) versus 52/229 (22%); RR 0.31; 95%CI 0.19 to 0.51) and pulmonary embolism. Data were insufficient to establish any effect on the incidence of fatal pulmonary embolism and overall mortality. Problems with skin abrasion and compliance were reported. REVIEWER'S CONCLUSIONS: U and LMW heparins protect against lower limb DVT. There is insufficient evidence to confirm either protection against pulmonary embolism or an overall benefit, or to distinguish between various applications of heparin. Foot and calf pumping devices appear to prevent DVT, may protect against pulmonary embolism, and reduce mortality, but compliance remains a problem. Good quality trials of mechanical methods as well as direct comparisons with heparin and low dose aspirin should be considered.

Complications of tibial shaft soccer fractures.

A retrospective study of AO type 42 tibial diaphyseal fractures that presented to a teaching hospital over a 54 month period was made to identify the proportion sustained whilst playing soccer, determine their characteristics and report treatment and outcome. Sport accounts for 73/329 (22.1%) of these fractures and soccer 58/73 (79. 5%) of these. All patients were male with mean age of 24.3 years (range 8-48). Fifty-four fractures were closed and 93.1% (54/58) were situated in the middle third or at the junction of the middle and distal thirds of the diaphysis. Fifty-six (96.6%) had simple or wedge patterns and 45 (77.6%) were right sided. Forty-four (76.2%) were treated non-operatively in plaster, 12 (20.3%) by intramedullary nails and two (3.4%) with external fixators. Two patients were lost to follow-up and the remaining 56 fractures united at a mean of 6.5 months. There were 21 complications in 19/56 (33.9%) patients which included 8/56 (14.3%) delayed/non-unions requiring surgery. There was a significantly higher complication rate for operated fractures (p<0.005) but no significant link to AO fracture type. Thus we cannot assume that treatment of these common fractures is without risk, especially if they are treated operatively.

Heparin, low molecular weight heparin and physical methods for preventing deep vein thrombosis and pulmonary embolism following surgery for hip fractures.

BACKGROUND: Hip fracture patients have a high risk of thromboembolic complications following surgical management. OBJECTIVES: To examine the effects of heparin (unfractionated (U), and low molecular weight (LMW) heparins), and physical methods (compression stockings, calf or foot pumps) for prevention of deep venous thrombosis (DVT) and pulmonary embolism after surgery for hip fracture in the elderly. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group trials register, Medline, Embase, and reference lists of published papers and books. We contacted trialists and other workers in the field. Date of most recent search: September 1996. SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating the use of heparins and physical agents for prevention of DVT and pulmonary embolism in patients undergoing surgery for hip fracture. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed methodological quality and extracted data. Trials were grouped into four categories (heparin versus control, mechanical versus control, LMW heparin versus U heparin, and miscellaneous) and results pooled where possible. MAIN RESULTS: The 26 included trials involved 2600 predominantly female and elderly patients. Overall, trial quality was disappointing. Ten trials involving 826 patients which compared U heparin with control, and four trials of 471 patients which compared LMW heparin with control, showed a reduction in the incidence of lower limb DVT (121/511 (24%) versus 203/519 (39%); Peto odds ratio 0.41; 95% confidence interval 0.31 to 0.55). There were insufficient data to confirm the efficacy of either agent in the prevention of pulmonary embolism. There was a non significant increase in overall mortality in the heparin group (46/420 (11%) versus 35/423 (8%); Peto odds ratio 1.39; 95% confidence interval 0. 86 to 2.23). Data were inadequate for all other outcomes including wound complications. There is insufficient evidence from five trials, involving 644 patients, to establish if LMW heparin was superior to U heparin. Most trials evaluating heparins had methodological defects. Four trials, involving 442 patients, testing mechanical pumping devices were also methodologically flawed, and so pooled results need to be viewed cautiously. Mechanical pumping devices may protect against DVT (12/202 (6%) versus 42/212 (19%); Peto odds ratio 0.24; 95% confidence interval 0.13 to 0.44). Although the limited data indicated a potential benefit, they were inadequate to establish any effect on the incidence of pulmonary embolism and overall mortality. Problems with skin abrasion and compliance were reported. REVIEWER'S CONCLUSIONS: U and LMW heparins protect against lower limb DVT. There is insufficient evidence to confirm either protection against pulmonary embolism or overall benefit, or to distinguish between various applications of heparin. Foot and calf pumping devices appear to prevent DVT, may protect against pulmonary embolism, and reduce mortality, but compliance remains a problem. Good quality trials of mechanical methods as well as direct comparisons with heparin should be considered.

Computed tomography scan scout film for measurement of femoral axis in knee replacement.

We conclude that the CT scout film is a more accurate and reproducible method for FAA measurement. The cost difference is minimal and might be expected to lessen as overheads are reduced for the CT scanner.

Remembering specific episodes of a scripted event.

Children's memory for a specific episode of a repeated event was investigated in 2 experiments. In Experiment 1, eighty 4- and 7-year-olds experienced a standard novel event 1, 2, or 4 times, followed by an episodic event for those children who had multiple standard event experiences. The episodic event involved the addition of both schema-typical and schema-atypical activities to the standard event. Following a 1-week delay, children were asked to recall both event types. Four-year-olds were more confused than older children regarding when the new activities had been experienced, although experience improved memory for the schema-atypical activities. In contrast, 7-year-olds were able to establish more accurate memories for both the schema-typical and the schema-atypical changes. Experiment 2 demonstrated that 4-year-olds could, however, establish distinct memories for both types of changes when the standard event was simplified. The results are discussed in terms of the development of the relation between script memory and memory for a specific instance of an event.

Possible salmonella osteomyelitis of spine following laser disc decompression.

We report a case of chronic discitis and vertebral osteomyelitis that we believe was caused by Salmonella typhimurium following laser decompression of the L4/5 disc for symptomatic disc protrusion in a 50-year-old Asian man. The infection was successfully treated with intravenous ceftriaxone combined with oral ciprofloxacin. We believe this to be the only report of such a complication following this procedure, which is generally without infective complications.

Attachment and emotion in autobiographical memory development.

The relation of attachment status to autobiographical memory was assessed in 3.5- to 4.5-year-olds. Of specific interest was the relation between attachment status and the emotional content of parent-child memory conversations. Forty-six mother-child dyads discussed four events designed to elicit positive and negative emotional themes. Both attachment status and gender moderated the emotional content of this memory talk. Mother-daughter dyads with insecurely attached girls engaged in relatively more negative memory talk than mother-daughter dyads with securely attached girls. However, the dyads of secure girls elaborated more often on both positive and negative emotional themes than did the dyads of insecure girls who primarily elaborated on positive themes. The relations between attachment status and emotion talk for mother-son dyads were inconsistent. Findings were discussed in terms of the role of attachment in the social construction of autobiographical memories.

The orthopaedic implications of peripheral limb ischaemia in infants and children.

Peripheral limb ischaemia is rare in children. We have treated only 12 infants and children with this condition in the past 15 years at the Royal Hospital for Sick Children in Glasgow. There were nine neonates and three older children. Most were suffering from life-threatening illnesses or severe infection. Two were born with ischaemic arms with no apparent cause. We have analysed the factors leading to ischaemia, the outcome of the initial treatment and the later orthopaedic problems. Two required amputation of both legs, one of an arm, two of feet and one of toes. Two had skin grafts. All surgery was performed after demarcation was well established and delayed closure was used after amputation. Five children developed limb-length discrepancy or an angular deformity. To date two have required additional corrective surgery.

Percutaneous reduction for closed nailing of femoral shaft fractures.

Fracture reduction devices for closed nailing of the femur have been described as an alternative to manual manipulation. They have consisted of various clamps and supports. These external methods can be difficult to use. We have used a Steinman pin on a T-clamp inserted percutaneously on to bone to gain a temporary reduction during intramedullary nailing.

Three-year-olds remember a novel event from 20 months: evidence for long-term memory in children?

Thirty-seven 3-year-old children, who had learned a 9-action event sequence ("making Play-Doh spaghetti") when they were 20 months old, returned to the lab to determine whether they would be able to verbally and/or behaviourally recall the event after a 12- to 22-month delay. Children originally participated in the event either one or three times and experienced different parts of the event either at three distinct locations (spatial condition) or at a single location (nonspatial condition). Results show very little evidence of long-term memory for the event after one to two years. Returning children did not verbally recall the event, and they did not perform more actions or sequence the event more accurately than controls, with the exception of the older experimental children who had a tendency to sequence the event more accurately than same-aged controls. Although the results indicate that young children's memory for novel events is not very enduring, there were individual differences in children's ability to remember the event. These differences are discussed in terms of potential differences in cognitive abilities and changing knowledge about retrieval strategies or memory.

A comparison of content-masking procedures for obtaining judgments of discrete affective states.

The purpose of this article is to investigate observers' use of acoustic cues to arrive at judgments of the speaker's affective state and to address current methodological limitations. Ninety-nine female undergraduates rated the level of excitement, happiness, and anger of speech stimuli under three content-masking procedures: low-pass filtering, random splicing, and reiterant speech. Each procedure preserves some forms of acoustic information while disrupting or degrading others. As predicted, the content-masking procedures generated bias in observers' affective ratings. Results are discussed in terms of the efficacy of the content-masking procedures and implications for the study of acoustic cues to speaker affect.

Meckel's diverticulum: should it be excised prophylactically in service personnel?

In a four month period in 1992 at a small military wing of a civilian hospital three Meckel's Diverticulae were removed from patients suspected of having complications in their vermiform appendix. One of the diverticulae was inflamed and was the cause of the symptoms. The second was a symptomatic but it and the appendix showed transmural granulomatous inflammation caused by infection with Yersinia pseudotuberculosis. The third also asymptomatic was found to contain carcinoid tumour. On investigation with urinary estimations of 5 Hydroxy Indole Acetic Acid there was no sign of residual carcinoid tumour in the patient. None of the patients has had complications from their surgery. Review of the literature shows that prophylactic excision of asymptomatic Meckel's Diverticulae to prevent possible complications is justified in persons under the age of 40 such as is the typical service population.

Event knowledge and early language acquisition.

The role of event knowledge in early language acquisition was investigated. Thirteen two-year-olds were observed interacting with their mothers over a five-week period. During weekly observational sessions, dyads interacted in both a familiar-event context and an unfamiliar-event context. Events were represented by complex toys (e.g. airport, marina, etc.). In the familiar-event, dyads interacted with the same event-toy during each observation period. In the unfamiliar-event, these same dyads interacted with a different novel toy during each observation period. The results indicated that children's increasing event knowledge facilitated their language development. Specifically, children's lexical type use, action verb use, and MLU increased in the familiar-event, but remained unchanged in the unfamiliar-event. Event knowledge also facilitated children's lexical token use. Results are discussed in terms of the role of event knowledge in language acquisition.

Knowledge, concepts, and inferences in childhood.

The role of knowledge in children's inferences was investigated in 3 experiments. Experiment 1 examined developmental changes in the role of categorical membership, perceptual appearance, and item complexity in inferences for natural kind and artifact concepts. Preschoolers (5-year-olds), second graders (8-year-olds), and fourth graders (10-year-olds) were taught novel properties about target concepts and asked whether each of 4 probes had those properties. Probes varied in category membership and perceptual appearance relative to the target item. Item complexity also varied. Experiments 2 and 3 examined inferences with known and unknown concepts for familiar and unfamiliar properties. Older children's knowledge led to differential weighting of categorical information over appearance but only for known concepts and/or familiar properties. Preschoolers made no distinction between category and appearance for either known or unknown concepts. Additionally, as target item complexity increased, older children made more inferences than preschoolers. No differences between inferences about natural kind and artifact concepts were found. The role of theories and knowledge in children's drawing of inferences is discussed.

Developmental changes in event memory.

Do developmental differences exist in children's organization of event memories? We explored this question by examining children's recall of standard features of a repeated event versus features that deviated from that event. 4- and 7-year-old children experienced an initially unfamiliar laboratory event (standard event) 1 or 3 times. Following the last visit, deviations from the standard event were introduced (deviation event). Children's recall was assessed 1 week later under free recall and contextual recall conditions. Younger children had more difficulty than older children distinguishing between the standard and deviation visits. That is, 4-year-olds were more confused regarding which event features occurred in the different event visits. 7-year-olds, in contrast, did a better job of correctly remembering the features of the standard and deviation visits. Implications for developmental changes in the organization of general and specific event memory are discussed.

Discourse and the acquisition of grammatical morphemes.

Adult recasts of child utterances have been shown to be related in a general way to the child's acquisition of syntactic structures. The current study had two aims. The first aim was to determine which feature(s) of recasts (i.e. reformulation, expansion, topic continuation, or reply) was responsible for facilitating language acquisition by comparing them to other maternal discourse models that were systematically defined by these properties. The second aim was to investigate this relation more specifically by relating adult discourse models of specific grammatical morphemes to the child's acquisition of those same morphemes. Again, recasts were of particular interest. Twelve mother-child dyads were videorecorded during one hour of naturalistic interaction when the children were 1; 10 and 2; 4. Results indicated that maternal recasts of specific morphemes were related to the acquisition of those same grammatical morphemes during certain developmental periods, whereas other grammatical morphemes were facilitated by expansions and topic continuations. These results are discussed in terms of the processes responsible for these effects.

Purification and Interconversion of Homoserine Dehydrogenase from Daucus carota Cell Suspension Cultures.

Homoserine dehydrogenase from cell suspension cultures of carrot (Daucus carota L.) has been purified to apparent homogeneity by a combination of selective heat denaturation, ion exchange and gel filtration chromatographies, and preparative gel electrophoresis. Carrot homoserine dehydrogenase is composed of subunits of equal molecular weight (85,000 +/- 5,000). During purification, the enzyme exists predominantly in two molecular weight forms, 180,000 and 240,000. The enzyme can be reversibly converted from one form to the other, and each has different regulatory properties. When the enzyme is dialyzed in the presence of 5 millimolar threonine, the purified enzyme is converted into its trimeric form (240,000), which is completely inhibited by 5 millimolar threonine and is stimulated 2.6-fold by K(+). When the enzyme is dialyzed in the presence of K(+) and absence of threonine, the purified enzyme is converted into a dimer (180,000), which is not inhibited by threonine and is only stimulated 1.5-fold by K(+). The enzyme also can polymerize under certain conditions to form higher molecular weight aggregates ranging in size up to 720,000, which also are catalytically active. This interconversion of homoserine dehydrogenase conformations may reflect the daily stream of events occurring in vivo. When light stimulates protein synthesis, the threonine pool decreases in the chloroplast, while K(+) concentrations increase. The change in threonine and K(+) concentrations shift the homoserine dehydrogenase from the threonine-sensitive to the threonine-insensitive conformation resulting in increased production of threonine, which would meet the demands of protein synthesis. The reverse process would occur in the dark.