Graft fixation in cruciate ligament reconstruction

Cruciate ligament reconstruction has progressed dramatically in the last 20 years. Anatomic placement of ligament substitutes has fostered rehabilitation efforts that stress immediate and full range of motion, immediate weightbearing, neuromuscular strength and coordination, and early return to athletic competition (3 months). This has placed extreme importance on secure graft fixation at the time of ligament reconstruction. Current ligament substitutes require a bony or soft tissue component to be fixed within a bone tunnel or on the periosteum at a distance from the normal ligament attachment site. Fixation devices have progressed from metal to biodegradable and from far to near-normal native ligament attachment sites. Ideally, the biomechanical properties of the entire graft construct would approach those of the native ligament and facilitate biologic incorporation of the graft. Fixation should be done at the normal anatomic attachment site of the native ligament (aperture fixation) and, over time, allow the biologic return of the histologic transition zone from ligament to fibrocartilage, to calcified fibrocartilage, to bone. The purpose of this article is to review current fixation devices and techniques in cruciate ligament surgery.

Relationship of satiety to postprandial glycaemic, insulin and cholecystokinin responses

The effect of plasma glucose on satiety and the capacity of carbohydrates to stimulate cholecystokinin (CCK) remain unclear. The aim of this study was to test the hypothesis that the magnitude of the postprandial plasma glucose and insulin response is inversely related to the CCK response and to subjective satiety. Seven healthy, male volunteers consumed equal carbohydrate portions (0.5 g/kg body weight) of six test meals (Rice Bubbles, Sustain, Vita-Brits, All-Bran, porridge and white bread) in random order after an overnight fast. An egg and bacon meal was consumed as a non-carbohydrate control providing 0.5 g protein/kg body weight. Serum CCK, plasma glucose and insulin and subjective satiety (measured by a rating scale) were assessed over 3 h and quantified using the glycaemic index (GI), insulin index (II), the peak satiety score and area under the incremental curve (AUC). The observed GIs (mean +/- SE) ranged from 42.5 +/- 2.6 for All-Bran to 116.2 +/- 11.4 for Rice Bubbles, using white bread as the reference food (GI = 100). Peak satiety scores varied eightfold from 0.21 +/- 0.4 for Sustain to 1.64 +/- 0.4 for All-Bran. Significant inverse relationships were observed between the peak satiety score and both the glycaemic and insulin index of the seven meals (r = -0.916, p less than 0.001 and r = -0.926, p less than 0.001). A direct relationship was observed between satiety (AUC) and the CCK response (AUC) (r = 0.73 p less than 0.01). The results suggest that glycaemic and insulin responses to carbohydrate foods are inversely proportional to the CCK response and satiety.

Possible benefit of GR43175, a novel 5-HT1-like receptor agonist, for the acute treatment of severe migraine

GR43175, a selective 5-HT1-like agonist, was given as an intravenous infusion in an open dose-ranging study to treat 46 attacks of severe migraine in 34 patients. The highest dose, 2 mg infused over 10 min in 24 severe attacks, resulted in rapid and complete relief of symptoms in 17 attacks (71%) and in improvement to a non-migrainous residual headache in 7 attacks. Treatment was well tolerated, the only adverse effects being transient feelings of heaviness and pressure, predominantly in the head. GR43175 may represent an important advance in the treatment of acute migraine.

A three-day course of dexamethasone therapy to prevent chronic lung disease in ventilated neonates: a randomized trial

BACKGROUND

Although several trials of early dexamethasone therapy have been completed to determine if such therapy would reduce mortality and chronic lung disease (CLD) in infants with respiratory distress, optimal duration and side effects of such therapy remain unknown.

PURPOSE

The purpose of this study was: 1) to determine if a 3-day course of early dexamethasone therapy would reduce CLD and increase survival without CLD in neonates who received surfactant therapy for respiratory distress syndrome and 2) to determine adverse effects associated with such therapy.

DESIGN

This was a prospective multicenter randomized trial comparing a 3-day course of dexamethasone therapy beginning at 24 to 48 hours of life to placebo therapy. Two hundred forty-one neonates (dexamethasone n = 118, placebo n = 123), who weighed between 500 g and 1500 g, received surfactant therapy, and were at significant risk for CLD or death using a model to predict CLD or death at 24 hours of life, were enrolled in the trial. Infants randomized to receive early dexamethasone were given 6 doses of dexamethasone at 12-hour intervals beginning at 24 to 48 hours of life. The primary outcomes compared were survival without CLD and CLD. CLD was defined by the need for supplemental oxygen at the gestational age of 36 weeks. Complication rates and adverse effects of study drug therapy were also compared.

RESULTS

Neonates randomized to early dexamethasone treatment were more likely to survive without CLD (RR: 1.3; 95% CI: 1.03, 1.7) and were less likely to develop CLD (RR: 0.6; CI: 0.3, 0. 98). Mortality rates were not significantly different. Subsequent dexamethasone therapy use was less in early dexamethasone-treated neonates (RR: 0.8; CI: 0.7, 0.96). Very early (</=7 days of life) intestinal perforations were more common among dexamethasone-treated neonates (8% vs 1%).

CONCLUSION

We conclude that an early 3-day course of dexamethasone therapy increases survival without CLD, reduces CLD, and reduces late dexamethasone therapy in high-risk, low birth weight infants who receive surfactant therapy for respiratory distress syndrome. Potential benefits of early dexamethasone therapy at the dosing schedule used in this trial need to be weighed against the risk for early intestinal perforation.

The treatment of inflammatory arthritis with methotrexate in clinical practice: treatment duration and incidence of adverse drug reactions

OBJECTIVE

To identify the proportion of patients with inflammatory arthritis who remain on methotrexate in the medium to long term and the incidence of side-effects in clinical practice.

METHOD

The study population comprised all patients with inflammatory arthritis treated with methotrexate and monitored in clinics under the auspices of Staffordshire Rheumatology Centre. Two clinical auditors collected data retrospectively from the computer database used to support monitoring of patients on disease-modifying anti-rheumatic drugs. Information was collected on duration of treatments and reasons for stopping treatment. For patients identified as having potentially serious side-effects or who died whilst taking methotrexate, further information on their outcome was collected from patients' medical notes and where applicable post mortem reports and death registers.

RESULTS

Between 1986 and 1999, 673 patients were treated with methotrexate, of whom 551 had a diagnosis of rheumatoid arthritis. From the Kaplan-Meier analysis, the probability of patients remaining on treatment 5 yr after starting methotrexate was 0.74. Three hundred and sixteen patients stopped methotrexate between 1986 and 1999. In 117 patients, the methotrexate was restarted. Seventy-two patients (10.7% of all patients) stopped because of inefficacy or patient choice or situation. Thirty-seven patients (5.5%) stopped methotrexate due to abnormal haematology (usually low neutrophils). Thirty-seven patients (5.5%) stopped methotrexate due to abnormalities in liver function tests. Life-threatening side-effects were identified in 12 patients (1.8%). These included six pneumonitis, five cytopenias and one disseminated varicella zoster. Two of these patients (0.3%) died, one from pneumonitis and one from disseminated varicella zoster. A total of 25 patients (3.7%) died while taking methotrexate and four died (0.6%) within 3 months of stopping methotrexate. One death (0.15%) was directly attributable to methotrexate (methotrexate pneumonitis).

CONCLUSION

This study has shown that methotrexate is well tolerated in clinical practice in the medium to long term. It has produced accurate data on the incidence of adverse effects of methotrexate in a local population in a non-research setting. It has identified the incidence of life-threatening side-effects to be 1.7% with one death (0.15%) directly due to methotrexate. This information should prove useful when recommending such treatment to patients with inflammatory arthritis.

Bisphosphonate therapy in fibrous dysplasia

Fibrous dysplasia is proliferation of fibrous tissue within the bone marrow causing osteolytic lesions and pathologic fractures. Recently, second generation bisphosphonates have shown promise in the treatment of patients with fibrous dysplasia. In the current study, six patients with fibrous dysplasia were treated with either oral alone or oral and intravenous bisphosphonates. The participants were observed for changes in N-telopeptide, pain score, and radiographic changes. In the current study, the combination bisphosphonate therapy diminished pain, prevented fractures, lowered N-telopeptide values, and led to partial resolution of fibrous dysplasia lesions.

Classification without identification in visual search

Six subjects scanned displays of random consonants for a single target which was (a) another consonant; (b) a given number; or (c) any number. A second group of six subjects took part in three comparable conditions with number displays, and letters or numbers as targets. Scanning time for a number in a letter display or a letter in a number display was more rapid than scanning for a target drawn from the same set as the background. Several unpractised subjects, and all the subjects who practised the task, were able to scan as fast through letters for “any number” as for a specific number, or conversely through digits. The finding of different scanning rates for two precisely physically specified targets, depending on which class they were drawn from, runs counter to an explanation of high-speed scanning in terms of the operation of visual feature analysers. It is suggested that familiar categorization responses may be immediate and may provide the basis for the discrimination of relevant from irrelevant items in rapid visual scanning.

Molecular analysis of katG gene mutations in strains of Mycobacterium tuberculosis complex from Africa

A sample of 124 isoniazid (INH)-resistant and 88 susceptible strains of Mycobacterium tuberculosis complex from south, central, and west Africa was analyzed by direct sequence analysis and PCR-restriction fragment length polymorphism analysis of their catalase-peroxidase (katG) genes. Point mutations at codon 315 were found in the genomes of 64% of INH-resistant strains, but no complete deletions were identified. Mutations at codon 463 were independent of INH resistance and were linked to the geographic origins of the strains.

Progressive infantile neurodegeneration caused by 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency: a novel inborn error of branched-chain fatty acid and isoleucine metabolism

We report a novel inborn error of metabolism identified in a child with an unusual neurodegenerative disease. The male patient was born at term and recovered well from a postnatal episode of metabolic decompensation and lactic acidosis. Psychomotor development in the first year of life was only moderately delayed. After 14 mo of age, there was progressive loss of mental and motor skills; at 2 years of age, he was severely retarded with marked restlessness, choreoathetoid movements, absence of directed hand movements, marked hypotonia and little reaction to external stimuli. Notable laboratory findings included marked elevations of urinary 2-methyl-3-hydroxybutyrate and tiglylglycine without elevation of 2-methylacetoacetate, mild elevations of lactate in CSF and blood, and a slightly abnormal acylcarnitine profile. These abnormalities became more apparent after isoleucine challenge. Enzyme studies showed absent activity of 2-methyl-3-hydroxybutyryl-CoA dehydrogenase (MHBD) in the mitochondrial oxidation of 2-methyl branched-chain fatty acids and isoleucine. Under dietary isoleucine restriction, neurologic symptoms stabilized over the next 7 months.

Accuracy of high tibial osteotomy: comparison between open- and closed-wedge technique

High tibial osteotomy is an established technique for the treatment of varus malaligned knees. This study analyses the difference between the amount of correction in the preoperative planning and the postoperative result. Furthermore, it compares the difference of the accuracy between open-wedge osteotomy and closed-wedge osteotomy. About 61 patients were either treated with open-wedge or closed-wedge high tibial osteotomy. Preoperative planning and postoperative analysis were performed with a special planning software. The influence of operative technique, aetiology, age, number of previous surgeries, amount of correction and accuracy of the correction compared to the preoperative planning were analysed. The overall postoperative mechanical axis differed form preoperative planning by 2.1° ± 1.7°. The accuracy in the open-wedge group (1.7° ± 1.6°) was significantly higher than in the closed-wedge group (2.6° ± 1.8°; P = 0.038). In patients with congenital varus deformity, the accuracy of the correction was significantly higher than in patients with post-traumatic deformity. The authors recommend open-wedge technique in combination with fixed-angle plates for high tibial osteotomy.

Phylogeography and divergence in the chloroplast genome of Western Australian Sandalwood (Santalum spicatum)

Western Australian sandalwood (Santalum spicatum) is widespread throughout Western Australia across the semiarid and arid regions. The diversity and phylogeographic patterns within the chloroplast genome of S. spicatum were investigated using restriction fragment length polymorphism analysis of 23 populations. The chloroplast diversity was structured into two main clades that were geographically separated, one centred in the southern (semiarid region) and the other in the northern (arid) region. Fragmentation due to climatic instability was identified as the most likely influence on the differentiation of the lineages. The lineage in the arid region showed a greater level of differentiation than that in the southern region, suggesting a higher level of gene flow or a more recent range expansion of sandalwood in the southern region. The phylogeographic pattern in the chloroplast genome is congruent with that detected in the nuclear genome, which identified different genetic influences between the regions and also suggested a more recent expansion of sandalwood in the southern region.

Didanosine compared with continuation of zidovudine in HIV-infected patients with signs of clinical deterioration while receiving zidovudine. A randomized, double-blind clinical trial. The Bristol-Myers Squibb AI454-010 Study Group

OBJECTIVE

To determine the benefits of switching to didanosine compared with continuing zidovudine among patients infected with human immunodeficiency virus (HIV) who have previously used zidovudine and have signs of clinical deterioration.

DESIGN

Randomized, double-blind, two-armed, parallel, comparative clinical trial with a blinded, compassionate crossover provision at 12 weeks.

SETTING

Outpatient clinics at 19 tertiary care medical centers.

PATIENTS

312 patients infected with HIV who had received zidovudine for 6 months or more, had CD4 cell counts of 300/mm3 or less, and had signs of clinical deterioration within 12 weeks before study entry.

INTERVENTION

Peroral didanosine tablets (600 mg/d adjusted for weight, "high dose") or zidovudine capsules (600 mg/d).

MEASUREMENTS

Primary study end points were death, a new acquired immunodeficiency syndrome (AIDS)--defining event, or the combination of two new or recurrent HIV-related diagnoses with a 50% decrease in CD4 cells.

RESULTS

Switching to didanosine was associated with fewer end points than continuing zidovudine (relative risk [RR] for zidovudine:didanosine = 1.5; 95% Cl, 1.1 to 2.0). This benefit was consistent across subgroups of patients with either AIDS-related complex or AIDS and was most apparent among those with a CD4 count at entry of 100/mm3 or more (RR = 2.2; Cl, 1.1 to 4.4).

CONCLUSIONS

This study shows a positive treatment effect for switching from zidovudine to didanosine among patients with either AIDS-related complex or AIDS and validates the common practice of using clinical signs or a decrease in the CD4 count as an indication for changing therapy.

Spontaneous soliton formation and modulational instability in Bose-Einstein condensates

The dynamics of an elongated attractive Bose-Einstein condensate in an axisymmetric harmonic trap is studied. It is shown that density fringes caused by self-interference of the condensate order parameter seed modulational instability. The latter has novel features in contradistinction to the usual homogeneous case known from nonlinear fiber optics. Several open questions in the interpretation of the recent creation of the first matter-wave bright soliton train [Nature (London) 417, 150 (2002)]] are addressed. It is shown that primary transverse collapse, followed by secondary collapse induced by soliton-soliton interactions, produces bursts of hot atoms at different time scales.

Comparison of three separate antiadhesive barriers for intraperitoneal onlay mesh hernia repair in an experimental model

Background

Adhesion formation is a common adverse effect in intraperitoneal onlay mesh (IPOM) surgery. Different methods of adhesion prevention have been developed, including coated meshes and separate antiadhesive barriers (SABs). In this study one type of mesh was tested with different SABs, which were fixed to the sutured mesh using fibrin sealant. The primary aim was to compare adhesion prevention between different SABs. Secondary aims were the assessment of tissue integration and evaluation of SAB fixation with fibrin sealant.

Methods

Thirty-two rats were randomized to one of three treatment groups (SurgiWrap®, Prevadh® and Seprafilm®) or a control group (no SAB). Animals were operated on with an open IPOM technique (8 per group). One macroporous polypropylene mesh per animal (2 × 2 cm) was fixed with four non-absorbable sutures. An antiadhesive barrier of 2·5 × 2·5 cm was fixed with fibrin sealant. After 30 days, adhesion formation, tissue integration, seroma formation, inflammation and vascularization were evaluated macroscopically and by histology.

Results

Prevadh® and Seprafilm® groups showed a significant reduction in adhesion formation compared with the control group. Tissue integration of the mesh was reduced in these groups. Fibrin sealant fixed the SAB to the mesh securely in all groups.

Conclusion

Prevadh® and Seprafilm® are potent materials for the reduction of adhesion formation. A potential relationship between effective adhesion prevention and impaired tissue integration of the implant was observed. Fibrin sealant proved an excellent agent for SAB fixation.

Weight-gain inhibition by lactose in Australian Aboriginal children. A controlled trial of normal and lactose hydrolysed milk

Weight-gain in 35 slightly undernourished Australian Aboriginal infants was studied in hospital (49 admissions) during a blind controlled trial of a pre-hydrolysed low-lactose milk preparation and reconstituted full-cream milk powder. Infants fed the lactose hydrolysed milk gained 70% more weight than those receiving normal milk. Better weight-gains were achieved in those on the lactose hydrolysed milk irrespective of percentage standard weight for age, the presence of diarrhoea on admission to the trial, and stool sugar concentrations. The use of low-lactose milk should be considered in nutritional aid programmes for undernourished children throughout the world.

Biomechanical comparison of quadriceps tendon fixation with patellar tendon bone plug interference fixation in cruciate ligament reconstruction

PURPOSE

The purpose of this study was to use current fixation techniques and compare the stiffness and ultimate tensile failure of the tendinous end of the quadriceps tendon (QT) with the bone plug end of the bone-patellar tendon-bone (BPTB) graft using current techniques of fixation.

TYPE OF STUDY

Randomized trial of elderly cadaver knees.

MATERIALS AND METHODS

Tibial and femoral biodegradable interference fixation and femoral EndoButton (Smith & Nephew, Acufex, Mansfield, MA) fixation in bone tunnels with the QT and the BPTB graft were compared by using 10 pairs of elderly cadavers and biomechanical testing. Two groups, fixation at time zero (simulating fixation in the operating room) and testing after 1, 000 loading cycles (simulating patient rehabilitation exercises), were used.

RESULTS

At time zero fixation, stiffness of the soft tissue QT tibial tunnel interference fixation was 59% less stiff than the stiffness of the interference fixation of a BPTB plug in a femoral tunnel (P =.11). The EndoButton femoral fixation resulted in a decrease in stiffness at time zero compared with femoral tunnel interference fixation of the soft tissue QT (P =.03). All groups improved stiffness with cycling the construct to 1,000 cycles.

CONCLUSIONS

Placement of the QT tendinous end of the graft in the femoral bone tunnel when using a interference fixation will approximate the stiffness of a bone plug in the tibial bone tunnel with interference fixation. The EndoButton fixation is not as stiff as either of the femoral interference fixation options. The addition of more than 20 loading cycles could remove laxity from the graft fixation-graft cruciate ligament complex and improve its stiffness.

Early clinical experience with subcutaneous GR43175 in acute migraine: an overview

In six European clinics 111 migraine patients were treated in a series of open dose-ranging studies with subcutaneous injections of 1 to 4 mg GR43175, a novel 5-HT 1-like receptor agonist. Response rates after 20-30 min were dose related and rose from 33% with 1 mg to 96% with 4 mg GR43175. Side effects were minor and transient. These promising results warrant confirmation in placebo-controlled double-blind trials. Migraine, treatment, 5-HT agonist, open studies.

Regional genetic differentiation in Western Australian sandalwood (Santalum spicatum) as revealed by nuclear RFLP analysis

Western Australian sandalwood, Santalum spicatum, is widespread in the semi-arid and arid regions of Western Australia, and there is some morphological variation suggestive of two ecotypes. The level and structuring of genetic diversity within the species was investigated using anonymous nuclear RFLP loci. Santalum spicatum showed moderate levels of genetic diversity compared to other Australian tree species. The northern populations in the arid region showed greater levels of diversity and less population differentiation than the southern populations in the semi-arid region due to differences in the distribution of rare alleles. Equilibrium between drift and gene flow in the northern populations indicated that they have been established for a long period of time with stable conditions conducive to gene flow. In contrast, the southern populations showed a relationship between drift and gene flow indicative of a pattern of fragmentation and isolation where drift has greater effect than gene flow. The different patterns of diversity suggest that the ecotypes in the two regions have been subject to differences in the relative influences of drift and gene flow during their evolutionary history.

Multiply-resistant Klebsiella pneumoniae: failure of spread in community-based elderly care facilities

Thirty-eight patients colonized with multiply-resistant, plasmid-mediated, expanded-spectrum beta-lactamase (SHV-2) producing Klebsiella pneumoniae (MRK), were discharged from hospital to 22 nursing or residential homes during a hospital-based outbreak, in the Grampian region of north-east Scotland. MRK colonized the urinary tract in 74%, stool in 58%, respiratory tract in 29% and wounds in 11%. Mean length of colonization was 160 days (range 7-548). Mean length of stay in the homes after aquisition of MRK was 298 days. Compared with a control group of MRK-negative residents, MRK-positive residents had histories of more hospital admissions, underlying disease and complete immobility. Evaluation of these homes showed high standards of care and good facilities. Despite prolonged carriage of MRK by the index cases there was no evidence of spread to the other 886 residents who were screened, and there was evidence of only minor environmental contamination. Given the available evidence, patients colonized with MRK can be accommodated in good-quality nursing and residential homes, on discharge from hospital, with little fear of spread to other residents.

Pyruvated galactose and oligosaccharides from Erwinia chrysanthemi Ech6 extracellular polysaccharide

The acidic extracellular polysaccharide of Ech6 was depolymerized by fuming HCl. The pyruvated sugars were isolated and characterized by methods that included a combination of low-pressure gel-filtration and high-pH anion-exchange chromatographies, methylation linkage analyses, mass (GC-MS and MALDI-TOF MS) and 1H NMR (1D and 2D) spectroscopies. The following pyruvated sugars were obtained: 4,6-O-(1-carboxyethylidene)-D-Galp; 4,6-O-(1-carboxyethylidene)- alpha-D-Galp-(1-->4)-beta-D-GlcAp-(1-->3)-D-Galp; 4,6-O-(1-carboxyethylidene)-alpha-D-Galp-(1-->4)-alpha-D-GlcAp- (1-->3)-alpha-D-Galp-(1-->3)-L-Fucp; 4,6-O-(1-carboxyethylidene)-alpha-D-Galp-(1-->4)-beta-D-GlcAp-(1-->3) -alpha-D-Galp-(1-->3)-L-[beta-D-Glcp-(1-->4)]-Fucp. These oligosaccharides present potential haptenes for the development of specific antibodies and confirm the partial structure proposed previously for the extracellular polysaccharide from Erwinia chrysanthemi Ech6 [Yang, B. Y.; Gray, J. S. S.; Montgomery, R. Int. J. Biol. Macromol., 1994, 16, 306-312].