Distal femur resection with endoprosthetic reconstruction: a long-term followup study

The distal femur is a common site for primary and metastatic bone tumors and therefore, it is a frequent site in which limb-sparing surgery is done. Between 1980 and 1998, the authors treated 110 consecutive patients who had distal femur resection and endoprosthetic reconstruction. There were 61 males and 49 females who ranged in age from 10 to 80 years. Diagnoses included 99 malignant tumors of bone, nine benign-aggressive lesions, and two nonneoplastic conditions that had caused massive bone loss and articular surface destruction. Reconstruction was done with 73 modular prostheses, 27 custom-made prostheses, and 10 expandable prostheses. Twenty-six gastrocnemius flaps were used for soft tissue reconstruction. All patients were followed up for a minimum of 2 years. Function was estimated to be good or excellent in 94 patients (85.4%), moderate in nine patients (8.2%), and poor in seven patients (6.4%). Complications included six deep wound infections (5.4%), six aseptic loosenings (5.4%), six prosthetic polyethylene component failures (5.4%), and local recurrence in five of 93 patients (5.4%) who had a primary bone sarcoma. The limb salvage rate was 96%. Distal femur endoprosthetic reconstruction is a safe and reliable technique of functional limb sparing that provides good function and local tumor control in most patients.     

Airway management by physicians wearing anti-chemical warfare gear: comparison between laryngeal mask airway and endotracheal intubation

BACKGROUND AND OBJECTIVE: To evaluate the ease with which successful insertion of a laryngeal mask airway can be performed in comparison with endotracheal intubation by medical personnel wearing chemical protective equipment. METHODS: Anaesthetists and non-anaesthetists (each n = 20) participated in the prospective comparative trial in an animal laboratory. The time and success rates of laryngeal mask airway vs. endotracheal tube insertions were measured as performed on anaesthetized monkeys. RESULTS: The results showed that the laryngeal mask airway was inserted more rapidly than the endotracheal tube by both groups (3.6 s and 28.6 s, P < 0.0001). Failed intubation occurred in 35% (anaesthetists) vs. 55% (non-anaesthetists) (P = 0.17). CONCLUSIONS: In view of the 100% success rate of insertion even in unfavourable conditions, the possible role of the laryngeal mask airway in the scenario of a toxic mass casualty event should be considered.     

Folic acid intake from fortification in United States exceeds predictions

In 1996, the U.S. Food and Drug Administration issued a regulation requiring that all enriched cereal-grain products be fortified with folic acid by January 1998. An average increase in folic acid intake of 100 micro g/d was projected as a result of this fortification. The objective of the present study was to estimate the effect of this fortification on the intake of folic acid and total folate, and on the prevalence of individuals with inadequate folate intake and with high folic acid intake. We used data on food and nutrient intake from 1480 individuals who participated in the 5th and 6th examinations of the Framingham Offspring Cohort Study. Fortification was instituted during the 6th examination so that 931 participants were examined before its implementation (nonexposed) and 549 after implementation (exposed). Published data on total folate in enriched cereal-grain products were used to correct folate content in these foods to reflect fortification. Among nonsupplement users, folic acid intake increased by a mean of 190 [95% confidence interval (CI): 176, 204] micro g/d (P < 0.001) and total folate intake increased by a mean of 323 (95% CI: 296-350) micro g dietary folate equivalents (DFE)/d (P < 0.001) in the exposed participants. Similar increases were seen among supplement users exposed to fortification. The prevalence of exposed individuals with total folate intake below the estimated average requirement (320 micro g DFE/d) decreased from 48.6% (95% CI: 44.2-53.1%) before fortification to 7.0% (95% CI: 3.1-10.9%) after fortification in individuals who did not use folic acid supplements. This prevalence was approximately 1% or less for users of supplements both before and after fortification. Prevalence of individuals with folic acid intake above the upper tolerable intake level (1000 micro g folic acid/d) increased only among supplement users exposed to fortification (from 1.3 to 11.3%, P < 0.001). No changes in folic acid intake were observed over time in the nonexposed participants. By these estimations, folic acid fortification resulted in a mean increase in folic acid intake that was approximately twice as large as previously projected.     

The glutamate carboxypeptidase gene II (C>T) polymorphism does not affect folate status in the Framingham Offspring cohort

Glutamate carboxypeptidase II (GCPII) hydrolyzes polyglutamyl folates before their absorption. Recently, a 1561 C>T polymorphism in the GCPII gene was reported to be associated with lower folate and higher homocysteine plasma concentrations in a small (n = 75) selected elderly population. In this study, we examined the effect of this polymorphism in 680 men and 644 women attending the fifth examination of the Framingham Offspring Study. At the time of sample collection, subjects were not taking any supplements and were not exposed to food folate fortification. GCPII genotypes were determined by allelic discrimination using Taqman probes. In the population as a whole, this mutation was not associated with lower plasma folate level or with elevated plasma homocysteine. In men, plasma folate concentrations were higher in carriers of the T allele compared with those homozygotes of the wild-type allele (P < 0.05), whereas in women folate concentrations did not differ between genotypes (P = 0.8). In its relationship to plasma folate, this mutation exhibited a weak interaction with age and gender only in older women (P = 0.05). Overall, our data show that the GCPII C1561T polymorphism is not a determinant of plasma folate or total homocysteine concentrations in this large cohort of participants from the Framingham Offspring Study.     

Laboratory investigation of an E. coli O157:H7 outbreak associated with swimming in Battle Ground Lake,Vancouver, Washington

Escherichia coli O157:H7 has been associated with a number of waterborne outbreaks, but it has never been recovered from an implicated environment. This paper reports on an August 1999 outbreak of E. coli O157:H7 associated with swimming in Battle Ground Lake in Clark Country, Washington. E. coli O157:H7 was isolated from duck feces, as well as from two water samples. The authors used pulsed-field gel electrophoresis to compare these isolates with patient isolates for genetic homology. All the isolates yielded the same restriction fragment patterns. In addition, using polymerase chain reaction, the authors found patient isolates and environmental isolates to have the same virulence factors (Stx, eaeA, and hly).     

Compliance testing of medical diagnostic x-ray equipment: three years' experience at a major teaching hospital in Western Australia

The impact of a formal compliance testing program has been evaluated three years post-implementation on a major teaching hospital (Sir Charles Gairdner Hospital) with 46 x-ray tubes located throughout 37 rooms. The mandatory program, implemented by the statutory authority in January 1997, called for all medical (including chiropractic and dental) equipment used in human diagnosis to be tested at prescribed frequencies using established protocols. The application of the required test methods demonstrated various non-compliance issues. Notices of non-compliance were received for approximately 60% of the equipment in the hospital following the equipment's first annual test. The reasons for, and the significance of, failure varied according to equipment category, test category, equipment use and equipment age. However, at the end of the third year of testing, approximately 75% of the tested x-ray units satisfied the compliance criteria. The main reasons for non-compliance were found to be design limitations of old technology and the current radiation legislation that makes it difficult for some older equipment to meet the relatively stringent criteria.     

Synaptic reentry reinforcement based network model for long-term memory consolidation

The conversion of newly formed declarative memories into long-term memories is known to be dependent on the hippocampus. Recent experiments suggest that memory consolidation requires reactivation of the NMDA receptor in CA1 during the initial week(s) after training. This led to the hypothesis that the repeated post-learning reinforcement of synaptic modifications, termed synaptic reentry reinforcement (SRR), is essential for long-term memory consolidation and storage. Based on experimental observations, we have built a computational model to further illustrate and explore the effect of the SRR process on the formation of long-term memory. We show that SRR is capable of strengthening and maintaining memory traces despite inherent variability in the system due to such processes as the turnover of synaptic receptors and their associated signaling and structural proteins. Furthermore, we demonstrate that new rounds of synaptic modification triggered by memory reactivation, either during conscious recall or sleep, could lead to the selective consolidation of a subset of memory traces. Finally, we show why the SRR process in the hippocampus is required during the initial post-training weeks for synaptic reinforcement based memory consolidation in the cortex.     

Firearm-related suicide among young african-american males

National trends in firearm-related suicides among African-American and white males in the age groups 15 to 19 years and 20 to 24 years from 1979 to 1997 were examined. The rates and percentages of suicide by firearms increased significantly more among African-American males than among white males. During the 19-year period, firearms accounted for about 70 percent and 64 percent of all suicides among males aged 15 to 19 years and 20 to 24 years, respectively. The results support the Surgeon General's 1999 call for greater awareness of the suicide risk among African-American males.