Harald Steen

Four-Strand Hamstring Tendon Autograft Compared with Patellar Tendon-Bone Autograft for Anterior Cruciate Ligament Reconstruction A Randomized Study with Two-Year Follow-Up

Seventy-two patients with subacute or chronic rupture of the anterior cruciate ligament were randomly assigned to autograft reconstruction with four-strand gracilis and semitendinosus tendon (N = 37) or with patellar tendon-bone (N = 35) from the ipsilateral side. The groups were similar in terms of age, sex, level of activity, degree of laxity, meniscal lesions found surgically, and rehabilitation program. The follow-up was performed at another hospital by independent observers after 6, 12, and 24 months. Sixty-one patients (32 with hamstring tendon grafts and 29 with patellar tendon grafts) complied with the follow-up routine for the full 24 months. No differences were found between the groups with respect to Cincinnati functional score, KT-1000 arthrometer measurements, or stairs hopple test results. The subjective result and the single-legged hop test result were better for the hamstring tendon group after 6 and 12 months, but no differences were found after 24 months. The hamstring tendon group showed better isokinetic knee extension strength than did the patellar tendon group after 6 months, but not after 12 and 24 months. There was a significant weakness in isokinetic knee flexion strength among the hamstring tendon group. Anterior knee pain was not significantly different between the groups, but kneeling pain was significantly less common in the hamstring tendon group after 24 months.

On the cost of reproduction in long-lived birds : The influence of environmental variability

Life history theory suggests that animals should balance their current investment in young against their chances to reproduce in the future. One fundamental prediction from the theory is that long-lived species should be restrictive in any increase of their current investment. It has been suggested that long-lived species, therefore, have evolved a fixed level of investment in young in order to maximize their own adult survival. However, recent experimental studies have shown that long-lived seabirds have a flexible reproductive performance and adjust their effort in raising young, both according to their own body condition and to the need of the chicks. In this study, we present a model of the optimal balance between reproductive effort and adult survival for long-lived birds breeding in a stochastic environment. During poor breeding conditions, maximum fitness is achieved either by not breeding at all, or by abandoning the brood. Beyond a certain threshold in breeding conditions, there is a steep increase in reproductive effort and an equally steep decrease in adult survival. The model is applied to two hypothetical long-lived seabirds differing in their potential fecundity. For the genotype with a potentially high fecundity, the model predicts a high threshold for breeding (i.e., breeding conditions need to be very good for the species to attempt breeding); above the threshold, the value of reproduction in terms of fitness is high. For the genotype with potentially low fecundity, the model predicts a low threshold for breeding, and the value of reproduction in terms of fitness is low. By increasing clutch size in the model, we examine the optimal response of the two genotypes to an experimental brood size manipulation. For both genotypes, the model predicts that the threshold for breeding is lower among controls than among enlarged broods, giving a range of possible outcomes of the experiment depending on breeding conditions. The few studies on brood enlargements in long-lived species carried out so far may support the predictions from the model.

Effect of Neuromuscular Training on Proprioception, Balance, Muscle Strength, and Lower Limb Function in Female Team Handball Players

ObjectiveIntroduction of a neuromuscular training program will increase muscle strength, balance, and proprioception in elite female handball players. DesignProspective intervention study. ParticipantsThirty-five female team handball players from 2 teams in the elite division participated. Their mean age was 23 (±2.5) years, and their mean weight was 69.2 (±7.3) kg. They had played handball for 14.9 (±3.2) years, 4.7 (±2.8) years at the top level. The total number of training hours per week was 10 to 11. InterventionBased on earlier studies and knowledge about common risk situations in team handball, an anterior cruciate ligament (ACL) injury prevention program with 3 different sets of exercises was developed, each set with a 5-step progression from simple to more challenging exercises. The teams were instructed to use the program a minimum of 3 times a week during a training period of 5 to 7 weeks, and then once a week during the season. The duration of each training session was approximately 15 minutes. Main outcome measuresBalance (KAT 2000), proprioception (threshold to detection of passive motion), muscle strength (Cybex 6000), and 3 functional knee tests. The players were tested pretraining (test 1) and 8 weeks (test 2) and 12 months (test 3) after the training started. ResultsThere was a significant improvement in dynamic balance between test 1 and test 2, with a balance index (BI) of 924 (±225) and 778 (±174), respectively (P = 0.01). The effect on dynamic balance was maintained 1 year after training (BI, 730 ± 156). For static balance, no statistically significant changes were found. For the other variables measured, there were no statistical differences during the study period. ConclusionThe ACL injury prevention training program improved dynamic balance in an elite team handball players.

DISTRIBUTION OF 5‐AMINOLEVULINIC ACID‐INDUCED PORPHYRINS IN NODULOULCERATIVE BASAL CELL CARCINOMA

Abstract— Microscopic fluorescence photometry incorporating a light‐sensitive thermo‐electrically cooled charge‐coupled device (CCD) camera was employed to investigate the fluorescence distribution of 5‐aminolevulinic acid (ALA)‐induced porphyrins in 22 patients with a total number of 52 noduloul‐cerative basal cell carcinomas (BCC) after topical ALA application with or without dimethylsulfoxide (DMSO)/ethylenediaminetetraacetic acid (EDTA) or after intravenous administration of ALA. Both localization patterns and amounts of ALA‐induced porphyrins in the BCC were studied. The ALA‐induced porphyrins were localized only in the superficial layers of the noduloulcerative BCC lesions after topical application of 20% ALA alone for 3 h. However, both the penetration of ALA into deep lesions and the production of the ALA‐induced porphyrin fluorescence were increased after topical administration of 20% ALA and 20% DMSO/4% EDTA for 3 h. Prior treatment with 99% DMSO for 15 min further enhanced the ALA penetration into the BCC lesions after topical application of the ALA/DMSO/EDTA mixture and produced more ALA‐induced porphyrins by a factor of about three compared with those treated with ALA alone. The penetration of ALA into the deep BCC lesions could also be increased by prolonging the time of topical application of 20% ALA/4% EDTA to 29–48 h (without DMSO). Intravenous injection of ALA led to a more homogeneous distribution of the ALA‐derived porphyrins in the whole noduloulcerative BCC lesions.

Geographical synchrony in microtine population cycles: a theoretical evaluation of the role of nomadic avian predators

A simple mathematical model is developed and analyzed to evaluate the hypothesis that regional synchrony in microtine population cycles is caused by nomadic avian predators. We show that predation by nomadic predators, capable of rapidly tracking the local prey densities, may indeed have a synchronizing effect. However, in contrast to the original hypothesis, our model requires no additional mechanism than predation (e.g. behavioural response of prey to predation) to produce synchronous prey cycles. In addition to the synchronizing effect, heavy predation pressure by nomadic predators is expected to shorten the period and dampen the amplitude of the prey cycles. Non-migrating predators having impact on their prey year round have a stronger synchronizing effect than migrating predators absent during the winter. We predict that geographic regions with few non-migrating predators are less likely to have synchronized microtine populations than regions with many such predators and that highly synchronized microtine populations have cycles with smaller amplitudes and shorter periods than microtine populations in geographic regions where local populations are not synchronized.

Sensitivity to changes over time for the IKDC form, the Lysholm score, and the Cincinnati knee score. A prospective study of 120 ACL reconstructed patients with a 2-year follow-up.

Abstract The purpose of this study was to determine: (1) the sensitivity to changes over time for the IKDC form, the Lysholm score, and the Cincinnati knee score, (2) the relationship between the IKDC form, the Lysholm score and the Cincinnati knee score, (3) the criterion validity of each graded variable included in the IKDC form, and (4) if a functional knee test should be included as a graded variable and part of the final result of the IKDC form. We included in this prospective study 120 subjects who underwent ACL reconstruction with follow-up times of 3 and 6 months, and 1 and 2 years after surgery. Outcome measurements were the graded variables of the IKDC form (IKDC1–4 and IKDC-final), the Lysholm score, the Cincinnati knee score, a visual analogue scale for patient’s satisfaction, knee joint laxity measurement (KT-1000 knee arthrometer), and two functional knee tests (the triple jump and stairs hopple tests). The IKDC1, IKDC2, IKDC-final, and the Lysholm score were not sensitive to changes over time. The Cincinnati knee score was highly sensitive to changes over time and showed significantly improved outcome between each follow-up. IKDC1–4 showed high criterion validity, indicating that the IKDC1–4 is a good means of documenting clinical examination at one follow-up, but not of detecting changes over time. The functional knee tests were significant outcome measurements after ACL reconstruction, and should be reported separately.

The Effect of Knee Bracing After Anterior Cruciate Ligament Reconstruction A Prospective, Randomized Study with Two Years’ Follow-up

The purpose of this prospective, randomized, clinical trial was to evaluate the effect of knee bracing after anterior cruciate ligament reconstruction. Sixty patients were randomized into one of two groups: Patients in the braced group wore rehabilitative braces for 2 weeks, followed by functional braces for 10 weeks, and patients in the nonbraced group did not wear braces. Data were recorded preoperatively, and postoperatively after 6 weeks, 3 and 6 months, and 1 and 2 years. The following outcome measures were used: KT-1000 arthrometry, the Cincinnati knee score, goniometry to record range of motion, computed tomography to determine thigh atrophy, Cybex 6000 isokinetic testing to evaluate muscle strength, three functional knee tests, and a visual analog scale to evaluate pain. At all follow-up times there were no significant differences between the two groups with regard to knee joint laxity, range of motion, muscle strength, functional knee tests, or pain. However, the Cincinnati knee score showed that patients in the braced group had significantly improved knee function compared with patients in the nonbraced group at the 3-month follow-up, even though the braced group showed significantly increased thigh atrophy compared with the nonbraced group at 3 months.

Spatial and Temporal Patterns of Small-Rodent Population Dynamics at a Regional Scale

Many species exhibit regional synchrony in population dynamics, and dif- ferent influential biotic and abiotic factors can be indicated by the observed scale of spatial synchrony. Here, we present analyses of spatial patterns of bank vole Clethrionomys glar- eolus population fluctuations, based on a 5-yr (1990-1994) trapping series obtained from 31 trap stations regularly spaced along a 256-km transect in the boreal forest in southeastern Norway. The bank vole was known to exhibit typically cyclic population dynamics in this region prior to this study. Bank vole fall densities exhibited fluctuations with little year-to-year variation; all s- indices (a measure of temporal variability) were below 0.5. There was a large scale trend in the temporal variability of the populations, with highest variablity at the south end and lowest in the middle of the transect. Analysis (Mantel correlogram) of the year-to-year rate of change of local populations showed that the opposite ends of the transect appeared to be most out of phase. At a smaller spatial scale (up to 30-40 km), local populations exhibited statistically significant synchrony in growth patterns. Spatiotemporal patterns in the dy- namics of local populations were not related to habitat quality. We suggest that the scale domain of population synchrony is related to intrinsic population scaling properties such as dispersal capacity.

Flow cytometry of bacteria: A promising tool in experimental and clinical microbiology

The DNA and protein content of individual Escherichia coli cells were measured at a rate of 10(4) cells per second with a sensitive microscope-based flow cytometer. DNA and protein were quantified by measuring the fluorescence from cells stained with a combination of the DNA-binding drugs Mithramycin and ethidium bromide and by scattered light, respectively. Separate experiments demonstrated that the light scatter signal was proportional to protein content. Dual parameter histograms (fluorescence/scattered light) of bacterial cultures gave detailed pictures of changes dependent upon the growth conditions and of the cell cycle kinetics. Effects of antibiotics could be readily detected and characterized after a few hours. The results demonstrate that flow cytometry is a promising method for application in experimental and clinical microbiology.

Photodynamic Therapy of Superficial Basal Cell Carcinoma with 5-Aminolevulinic Acid with Dimethylsulfoxide and Ethylendiaminetetraacetic Acid: A Comparison of Two Light Sources

Abstract The aim of this prospective randomized study was to compare the clinical and cosmetic outcome of superficial basal cell carcinomas (BCC), using either laser or broadband halogen light, in photodynamic therapy with topical 5-aminolevulinic acid (ALA). A total of 83 patients with 245 superficial BCC were included in the study. Standard treatment involved 15 min of local pretreatment with 99% dimethylsulfoxide (DMSO) before topical application of 20% ALA with DMSO (2%) and ethylendiaminetetraacetic acid (2%) as cofactors for 3 h before light exposure with either laser or a broadband lamp (BL). A complete response was achieved in 95 lesions (86%) in the laser group and 110 lesions (82%) in the BL group 6 months after treatment. Of these, 80 lesions (84%) in the laser group and 101 lesions (92%) in the lamp group were independently evaluated to have an excellent or good cosmetic post-treatment score. No serious adverse events were reported. This study shows that there is no statistical significant difference in cure the rate (P = 0.49) and the cosmetic outcome (P = 0.075) with topical application of a modified ALA-cream between light exposure from a simple BL with continuous spectrum (570–740 nm) or from a red-light laser (monochromatic 630 nm). Cost and safety are further elements in favor of the BL in this setting.