Paracellular drug transport across intestinal epithelia: influence of charge and induced water flux

The influence of drug charge and transepithelial water flux on passive paracellular drug transport was investigated in Caco-2 cell monolayers and rat ileal mucosa in vitro. Three small hydrophilic compounds with different net charges (creatinine, erythritol and foscarnet) were used as model drugs. A hypotonic glucose-rich solution was applied apically to induce epithelial absorption of water. In the Caco-2 monolayers, permeability to creatinine (positively charged) was 25-fold greater than to foscarnet (negatively charged), indicating a pronounced cation selective paracellular permeability. During apical exposure to the hypotonic glucose-rich solution, transport of all model drugs increased in both the absorptive and secretory directions. This enhanced transport coincided with a decrease in transepithelial resistance. Further, fluorescence and transmission electron microscopy indicated dilatations of the paracellular spaces but no damage to the cell membranes. These findings suggested that the enhancement in drug transport was attributable to increased paracellular tight junction permeability rather than to "solvent drag". In the ileal segments, mucosal exposure to the hypotonic glucose-rich solution had no effect on transepithelial resistance and only a marginal increase in drug transport was observed. Taken together, the modest absorption enhancement demonstrated in the in vitro models agrees with results obtained in vivo, supporting the conclusion that a more pronounced disruption of the tight junction barrier than that obtained through stimulation of epithelial absorption of water is required for efficient enhancement of paracellular intestinal drug absorption.

A comparison of results after arthroscopic anterior cruciate ligament reconstruction in female and male competitive athletes. A two- to five-year follow-up of 429 patients

The aim of this study was to compare the results after arthroscopic anterior cruciate ligament reconstruction in female and male competitive athletes who had a pre-injury Tegner activity level of > or =7 and a non-injured contralateral anterior cruciate ligament. One hundred and thirty-three female and 296 male patients were followed at 38 (21-68) months after the index operation. All the patients were operated on by experienced knee surgeons using patellar tendon autografts and interference screw fixation. At the index operation the median age of the female patients was 23 (1645) years and the median age of the male patients was 26 (16-47) years. The reconstruction was performed a median of 10 (0-141) and 10 (0-203) months after the injury in women and men respectively. The patients were re-examined by independent observers. At the follow-up, the median Lysholm score was 89 (38-100) points in the female group and 90 (22-100) points in the male group (P=0.015). The IKDC evaluation system, subjective anterior knee pain, subjective evaluation of the results, the knee-walking test and the KT-1000 tests revealed no differences between the groups. The mean (+/-2 SD) pre-injury Tegner activity level was 8.1 (+/-1.9) (median 8 (7-10)) in the female group and 8.4 (+/-1.8) (median 9 (7-10)) in the male group (P=0.003). At the follow-up, the Tegner activity level was 6.2 (+/-3.8) in the female group and 6.8 (+/-3.6) in the male group (P=0.012). At the follow-up, the Tegner activity level had decreased by 1.9 (+/-3.8) for the women and 1.6 (+/-3.3) for the men, as compared with the pre-injury level (n.s.). The difference between the performed and the desired activity level at the follow-up was 1.1 (+/-3.2) in the female group and 0.9 (+/-3.0) in the male group (n.s.). In the female group 53/133 (40%) and in the male group 115/296 (39%) returned to the pre-injury activity level (n.s.). The median one-leg-hop quotient was 93 (0-116)% in the female group and 96 (0-130)% in the male group (P=0.006). Concomitant meniscal injuries prior to the index operation, at the index operation or during the follow-up period were found in 64/133 (48%) women and in 185/ 296 (62%) men (P<0.01). The main conclusion was that the overall results in female and male athletes were comparable two to five years after the anterior cruciate ligament reconstruction. However, concomitant meniscal injuries were more common in male than females athletes after anterior cruciate ligament injuries.

The localization of the infrapatellar nerves in the anterior knee region with special emphasis on central third patellar tendon harvest: a dissection study on cadaver and amputated specimens

The aim of this dissection study on cadaver and amputated specimens was to determine the position of the infrapatellar nerves in the anterior knee region, and to investigate whether it would be possible to harvest the patellar tendon through two small vertical incisions, leaving the infrapatellar nerves undamaged and the major part of the paratenon intact. The infrapatellar nerve did not pass through the area between the apex of the patella and the tibial tubercle in 1 of 60 specimens. The nerve passed through this area as one branch in 15 of 60 specimens, as two branches in 37 of 60, as three in 6 of 60, and as four in 1 of 60 specimens. The distance from the apex of the patella to the infrapatellar nerve or the uppermost branch of the nerve was 30 mm (+/- 27 mm [2 SD]). The distance from the tibial tubercle to the infrapatellar nerve or the lowermost branch of the nerve was 27 mm (+/- 27 mm [2 SD]). In one specimen, the infrapatellar nerve passed 10 mm distal to the tibial tubercle. In 4 of 60 specimens, a branch of the infrapatellar nerve passed just above the tibial tubercle, and in 2 of 60 a branch passed just above the apex of the patella. In 19 of 20 specimens in which the harvesting procedure was performed, the infrapatellar nerve or the nerve branches were undamaged. The length of the undamaged paratenon was 27 mm (+/- 23 mm [2 SD]). This study showed that it was possible to harvest consistent bone-patellar tendon-bone autografts through two vertical 25-mm incisions, leaving the infrapatellar nerve undamaged and the paratenon partially intact in the majority of the cadaver and amputated specimens.

Magnetic resonance imaging of the patellar tendon after harvesting its central third: a comparison between traditional and subcutaneous harvesting techniques

The aim of this study was to compare the 2-year results after anterior cruciate ligament reconstruction using patellar tendon autografts harvested through a paratenon-splitting, traditional technique (group A) with the results of a subcutaneous technique aiming at protecting the infrapatellar nerves and the paratenon (group B). Special emphasis was placed on evaluating the donor site. Magnetic resonance imaging (MRI) of the patellar tendon was performed to evaluate the reconstitution after harvesting its central third. Examinations of knee-walking ability and assessments of anterior knee sensitivity were made in order to evaluate donor-site discomfort and the function of infrapatellar nerves. Seventy-two consecutive patients were included in the study; group A comprised 35 patients and group B, 37 patients. At the 2-year follow-up, the Tegner activity level, the Lysholm score, and the IKDC evaluation system showed no significant differences between groups A and B. The median loss of normal anterior knee sensitivity was 16 cm2 (range, 0 to 200 cm2) in group A and 0 cm2 (range, 0 to 285 cm2) in group B (P = .20). In group A 20% of the patients and in group B 58% had normal sensitivity (P < .01). MRI showed that the donor-site gap (area corresponding to non-tendinous-like tissue signal) was 5 mm (range, 0 to 9 mm) in group A and 2 mm (range, 0 to 5 mm) in group B (P < .0001). At 2-year follow-up, the subcutaneous graft-harvesting technique resulted in less disturbance of anterior knee sensitivity and a smaller donor-site gap than the traditional technique.

Comparison of arthroscopic one-incision and two-incision techniques for reconstruction of the anterior cruciate ligament

The purpose of this study was to assess the outcome of arthroscopic anterior cruciate ligament reconstruction performed using either the 'one-incision' technique or the rear-entry 'two-incision' technique. A series of 221 consecutive patients who underwent anterior cruciate ligament reconstruction was reviewed retrospectively. In the study population, two subgroups were defined. Group A consisted of 118 patients who underwent reconstruction using the one-incision transtibial endoscopic technique and Group B consisted of 103 patients who underwent reconstruction using the two-incision technique. The groups were comparable in terms of age, sex and activity level. The follow-up was performed after 47 (40-68) months in Group A and 55 (40-68) months in Group B. The Lysholm score at the final follow-up was significantly lower in Group A (90, 38-100) than in Group B (94, 34-100) (P = 0.002). The median KT-1000 total side-to-side difference was 1.5 (-6 to 7.5) mm in Group A, and 2.0 (-3.5 to 9) mm in Group B (n.s.). No significant difference between the groups was found when the IKDC evaluation system was used. Four intra-operative complications were registered in Group A and none in Group B (P = 0.06). No significant difference was found in terms of anterior knee pain, the one-leg-hop quotient or the activity level at the final follow-up. In this study the two methods gave similar and satisfactory results. Serious intraoperative complications were, however, recorded in four cases when the one-incision technique was used.

Adsorption and activity of Trichoderma reesei cellobiohydrolase I, endoglucanase II, and the corresponding core proteins on steam pretreated willow

The adsorption and the hydrolytic action of purified cellulases of Trichoderma reesei, namely, cellobiohydrolase I (CBH I), endoglucanase II (EG II), and their core proteins, on steam-pretreated willow were compared. The two enzymes differed clearly in their adsorption and hydrolytic behavior. CBH I required the cellulose-binding domain (CBD) for efficient adsorption and hydrolysis, whereas EG II was able to adsorb to steam pretreated willow without its CBD. Absence of the CBD decreased the hydrolysis of cellulose by EG II, but the decrease was less pronounced than with CBH I. A linear relationship was observed between the amount of enzyme adsorbed and the degree of hydrolysis of cellulose only for CBH I. EG II and EG II core appeared to be able to hydrolyze only 1 to 2% of the substrate regardless of the amount of protein adsorbed.

Analysis of subjective, objective and functional examination tests after anterior cruciate ligament reconstruction. A follow-up of 527 patients

This study included 527 patients (178 female and 349 male) with unilateral anterior cruciate ligament (ACL) rupture who underwent arthroscopic ACL reconstruction using bone-patellar tendon-bone autograft and interference screw fixation. The follow-up examination was performed by independent observers at a median of 38 (21-68) months after the index operation. At the follow-up, the Lysholm score was 86 (14-100) points, the Lysholm instability subscore was 22 (0-25) points and the Lysholm pain subscore was 19 (0-25) points. The Tegner activity level was 6 (1-10). The one-leg-hop test was 91 (0-167)% of the non-injured knee. The difference in the anterior side-to-side laxity as measured with the KT-1000 arthrometer at 89 Newton (N) was 1.5 (-5-13) mm and the total KT-1000 side-to-side difference at 89 N was 2 (-7-11) mm. Using the International Knee Documentation Committee (IKDC) evaluation system, 177 (33.6%) patients were classified as normal (group A), 211 (40%) as nearly normal (group B), 109 (20.7%) as abnormal (group C) and 30 (5.7%) as severely abnormal (group D). The highest correlation coefficients were recorded between the IKDC evaluation system and the Lysholm score (p = 0.66), the patients' subjective evaluation (p = 0.53), the Tegner activity level (p = 0.34), all the laxity tests (p > or = 0.34) and the one-leg-hop test (p = 0.28). The resumption of sporting activities and work as evaluated by the Tegner activity level correlated with the patients' subjective evaluation (p = 0.34) but did not correlate with the laxity tests, i.e., the manual Lachman test (p = -0.06) and the total and anterior KT-1000 tests (p = -0.06). Furthermore, none of the laxity tests correlated with the functional tests or the patients' subjective evaluation. We conclude that the IKDC evaluation system is a reliable and useful tool for evaluating the post-operative outcome after an ACL reconstruction.

Subacute versus delayed reconstruction of the anterior cruciate ligament in the competitive athlete

The objective of this study was to compare the function and activity level in patients with anterior cruciate ligament injuries, who participated in competitive sports (Tegner activity level > or = 7) and underwent a reconstruction of the anterior cruciate ligament, either subacute (2-12 weeks, group I) or late (12-24 months, group II) after the injury. The patients in group I (n = 97) were comparable with those in group II (n = 103) in terms of gender, age, preinjury activity level, and the reconstruction technique. At the final follow-up (2-5.5 years after the operation), the Lysholm score, the IKDC evaluation system and the one-leg-hop test revealed no differences between the groups. There were also no differences between the groups in terms of the patients' subjective evaluation or expectations. The Tegner activity level at follow-up was 8 (range 2-10) in group I and 6 (range 2-9) in group II (P = 0.0001). The same thing was found in terms of the desired Tegner activity level, which was 9 (range 4-9) in group I and 7 (range 3-10) in group II (P = 0.0002). The KT-1000 laxity meter revealed a total side-to-side difference of 1.5 mm (-3.5-8.5) in group I and 1.5 mm (-3.5-7) in group II (NS). Associated meniscal surgery between the index injury and the reconstruction, or during the reconstruction, was performed in 37/97 (38%) of the patients in group I and 59/103 (57%) of the patients in group II (P < 0.01). This study revealed that competitive athletes who underwent reconstruction at a subacute stage after the anterior cruciate ligament injury had a higher activity level 2-5.5 years after the index operation, as well as a higher desired level of activity compared to athletes who had the reconstruction delayed by 12-24 months. Furthermore, meniscal injuries were significantly more frequent if the reconstruction was delayed.

Effects of anaesthetics and lazaroid U-83836E on survival of transplanted rat dopaminergic neurones

We investigated whether different methods of anaesthesia, used on the pregnant rat when collecting embryonic donor tissue, and a lipid peroxidation inhibitor (lazaroid U-83836E) affect the survival of grafted embryonic dopaminergic neurones in hemiparkinsonian rats. There was no difference in either functional recovery or survival of dopaminergic neurones between the different euthanasia groups: (a) isoflurane sedation followed by cervical dislocation, (b) equithesin- or (c) euthatal-anaesthesia. However, lazaroid-treatment enhanced both behavioural recovery and transplant survival.

Serial magnetic resonance imaging of the donor site after harvesting the central third of the patellar tendon. A prospective study of 37 patients after arthroscopic anterior cruciate ligament reconstruction

The aim of this prospective study was to follow the development of repair tissue in the donor-site area using serial magnetic resonance imaging (MRI) evaluation and to assess whether the MRI findings were correlated with donor-site morbidity. Thirty-seven consecutive patients with unilateral anterior cruciate ligament injuries undergoing elective reconstruction of the ligament were included in the study. They were aged 27 (range 14-50) years. The graft was harvested through two 25-mm vertical incisions with the aim of protecting the infrapatellar nerve and sparing the paratenon. The tendon defect was left open. The patients underwent MRI evaluation at 6 weeks, 6 months and 27 months postoperatively. A final clinical follow-up was made 25 (range 23-29) months postoperatively. MRI demonstrated that the donor-site gap, i.e. the area corresponding to a pathological non-tendinous-like tissue signal, was 9 (range 4-18) mm at 6 weeks, 5 (range 2-14) mm at 6 months and 2 (range 0-5) mm at 27 months. The size of the donor-site gap had significantly decreased at 6 months compared with 6 weeks (P = 0.0001), as well as at 27 months compared with 6 months (P = 0.0001). We conclude that the patellar tendon at the donor site healed gradually, as expressed by a decrease in the area of non-tendinous-like tissue signal on the serial MRI evaluations.

Complications following arthroscopic anterior cruciate ligament reconstruction. A 2-5-year follow-up of 604 patients with special emphasis on anterior knee pain

The aim of the study was to assess knee function after arthroscopic anterior cruciate ligament reconstruction and to analyse complications impeding rehabilitation, additional surgery until the final follow-up, as well as residual patellofemoral pain and donor-site problems. Between 1991 and 1994, 635 patients were operated on using patellar tendon autografts and interference screw fixation. Of these, 604 (95.1%) patients (403 male and 201 female) were re-examined by independent observers at the final follow-up 38 (range 21-68) months post-operatively. The Lysholm score was 85 (range 14-100) points and the Tegner activity level was 6 (range 1-10). Using the IKDC score, 206 patients (34.1%) were classified as normal, 244 (40.4%) as nearly normal, 122 (20.2%) as abnormal and 32 (5.3%) as severely abnormal. In patients with an uninjured contralateral knee (n = 527), the KT-1000 revealed a total side-to-side difference of 1.5 (range -7-11) mm, and 384/527 (72.9%) had a side-to-side difference of < or = 3 mm. The one-leg-hop test was 95% (range 0%-167%). One or more complications impeding rehabilitation were recorded in 184/604 patients (30.5%). The most common was an extension deficit (> 5 degrees), in 81 patients (13.4%). During the period until the final follow-up, 196 re-operations were performed in 161/604 (26.7%) patients. More than one re-operation was required in 27 patients. Shaving and anterior scar resection due to extension deficit were the most common procedures performed (on 65 occasions). Moderate to severe subjective anterior knee pain related to activity, walking up and down stairs, and sitting with the knee flexed was found in 203/604 patients (33.6%). The median loss of anterior knee sensitivity was 16 (range 0-288) cm2. Patients with a full range of motion had less anterior knee pain than patients with isolated flexion or extension deficits, or combined flexion and extension deficits (P < 0.05, P = 0.08 and P < 0.001, respectively). Patients with a full range of motion had less anterior knee pain than patients with extension deficits (with and without flexion deficits) (P < 0.001). Patients with a full range of motion and a minimal loss (< or = 4 cm2) of anterior knee sensitivity had significantly (P < 0.01) less subjective anterior knee pain than patients who did not fulfil these criteria. A considerable number of complications hindering the rehabilitation and conditions requiring additional surgery until the final follow-up were recorded. Anterior knee pain and problems with knee-walking were correlated with the loss of range of motion and anterior knee sensitivity.

Role of a novel photosystem II-associated carbonic anhydrase in photosynthetic carbon assimilation in Chlamydomonas reinhardtii

Intracellular carbonic anhydrases (CA) in aquatic photosynthetic organisms are involved in the CO2-concentrating mechanism (CCM), which helps to overcome CO2 limitation in the environment. In the green alga Chlamydomonas reinhardtii, this CCM is initiated and maintained by the pH gradient created across the chloroplast thylakoid membranes by photosystem (PS) II-mediated electron transport. We show here that photosynthesis is stimulated by a novel, intracellular alpha-CA bound to the chloroplast thylakoids. It is associated with PSII on the lumenal side of the thylakoid membranes. We demonstrate that PSII in association with this lumenal CA operates to provide an ample flux of CO2 for carboxylation.

Reconstruction of the anterior cruciate ligament: comparison of outside-in and all-inside techniques

The aim of this prospective study was to compare two arthroscopic techniques for reconstructing the anterior cruciate ligament, the "outside-in" (two incisions) and the "all-inside" (one incision) techniques. The results obtained for 30 patients operated on using the "outside-in" technique (group I) were compared with those for 29 patients operated on using the "all-inside" technique (group II). Before surgery, there were no significant differences between the groups in terms of Lysholm score, Tegner activity level, patellofemoral pain score, or knee laxity. Both groups displayed significant improvements in Lysholm score after 24 months, from 69 (16) to 91 (9) in group I and from 70 (17) to 90 (15) in group II (means (SD)). There were also significant improvements in patellofemoral pain scores in both groups, from 13 (6) to 18 (5) in group I and from 14 (6) to 18 (4) in group II after 24 months. No difference was found between the groups in knee stability at the 24 month follow up. The IKDC score was identical in both groups at follow up. The operation took significantly longer for patients in group I (mean 94 (15)) than for those in group II (mean 86 (20)) (p = 0.03). The mean sick leave was 7.7 (6.2) weeks in group I and 12.3 (9.7) weeks in group II (p = 0.026), indicating that there may be a higher morbidity associated with the "all-inside" technique. It can be concluded that there were no significant differences between the two different techniques in terms of functional results, knee laxity, or postoperative complications. The results were satisfactory and the outcome was similar in both treatment groups.

Bone mineral assessments in the calcaneus after anterior cruciate ligament injury. An investigation of 92 male patients before and two years after reconstruction or revision surgery

The aim of this study was to assess the Bone Mineral Areal mass (BMA) in the calcaneus of male patients with unilateral anterior cruciate ligament (ACL) injury before and after reconstruction and to assess whether the BMA ratio or the BMA of the injured and uninjured side correlated with the level of activity, functional performance or the time period between the injury and the reconstruction. Ninety-two male patients with unilateral ACL injury were included in the study. The BMA was analysed immediately prior to surgery: a median of 11 (2-192) months after the injury in 30 patients aged 26 (15-41) years scheduled for primary ACL reconstruction (Group A). Forty-nine patients aged 29 (18-49) years had their BMA analysed a median of 24 (23-29) months after the primary ACL reconstruction (Group B). Thirteen patients aged 27 (21-39) years had their BMA analysed a median of 24 (20-45) months after ACL revision surgery (Group C). The median BMA ratio (injured side/uninjured side) was 96 (88-105)% in Group A, 96 (86-118)% in Group B and 95 (83-111)% in Group C. In all three groups, the median BMA value in the calcaneus was significantly lower on the injured side compared with the uninjured side (P=0.001, P=0.0003, P=0.01 in Groups A, B and C, respectively). The time period between the injury and the reconstruction neither correlated with the BMA ratio nor the BMA of the injured or the uninjured side in Group A. The level of activity as measured by the Tegner activity level and the functional performance as measured by the one-leg-hop quotient did not correlate with the BMA ratio in any of the groups. In the 49 patients with a primary ACL reconstruction (Group B), the post-operative Tegner activity level correlated with the BMA, on both the injured and uninjured side (P=0.0003, P=0.0005, respectively), when the BMA was assessed two years after the index operation. Male patients with unilateral ACL injury had a significantly lower BMA in the calcaneus on the injured side compared with the uninjured side before primary reconstruction, two years after primary reconstruction and two years after revision surgery. The time period between the injury and the index operation did not correlate with the BMA. A high level of activity correlated with the BMA on both the injured and the uninjured side two years after primary reconstruction.

Bioabsorbable tacks for arthroscopic treatment of recurrent anterior shoulder dislocation

Seventy-eight patients (82 shoulders) with symptomatic, recurrent anterior post-traumatic shoulder instability and Bankart lesions were operated on with bioabsorbable tacks (Suretac fixators). All the patients were followed by an independent observer, with a median follow-up period of 27 (21-63) months. The recurrence rate was 8/82 (10%). The median Rowe score was 93 (37-100) points. The median Constant score for the index shoulders was 90 (34-100) points, compared with 93 (80-100) points for 59 non-operated healthy shoulders from the same cohort (P=0.03). The external rotation in abduction was 93 (50-135) degrees compared with 105 (75-145) degrees for the control shoulders (P=0.0018). Arthroscopic shoulder stabilization using bioabsorbable Suretac fixators appears to produce reliable results if used in patients with post-traumatic shoulder instability and a Bankart lesion.

The Swedish SF-36 Health Survey III. Evaluation of criterion-based validity: results from normative population

Assumptions of the variation in SF-36 scale scores were tested in relation to external criteria in 8930 respondents comprising the Swedish norming population. Physical health scales were strongly associated with age, while small differences were found for the Mental Health scale across age groups. Females reported poorer health than males, particularly in ages between 30-40 and over 70. Worse health profiles were associated with social risk factors (unemployment, divorce, etc.). The disability pension rate was strongly related to reduced Physical Functioning and increased Bodily Pain. The use of medical care was reflected in general health scores (i.e., the lower the scale score, the higher the care consumption). Self-reported physical and psychological symptoms were selectively related to SF-36 scales. All SF-36 scales, except Mental Health, were more strongly related to ratings of health satisfaction than to global quality of life. Combinations of the SF-36 well-being scales explained a substantial part of the variance of these ratings. In conclusion, the performed criterion-validity tests support the cross-cultural stability of the SF-36.

The Swedish SF-36 Health Survey II. Evaluation of clinical validity: results from population studies of elderly and women in Gothenborg

The validity of the Swedish SF-36 Health Survey was examined, replicating techniques used in the U.S. validation. Principal components analysis was used to test the internal structure of the eight SF-36 scales in relation to hypothesized associations with the two major dimensions of health--physical and mental. Hypothesized relationships between scales and external criteria were also examined by means of clinical group contrasts. Both the principal components analysis and clinical group contrasts largely replicated U.S. findings, which supported the cross-cultural stability of the SF-36 in Sweden. As expected, the Physical Functioning and Mental Health scales were most sensitive to clinical manifestations of medical and mental health, respectively. The General Health scale was associated more with physical than mental health. However, the Social Functioning scale and particularly the Vitality scale were more related to mental health in Sweden than in the corresponding U.S. study. Cultural differences and variation in study samples and selection criteria were suggested as possible explanatory factors for these differences.

Gene discovery in the wood-forming tissues of poplar: analysis of 5, 692 expressed sequence tags

A rapidly growing area of genome research is the generation of expressed sequence tags (ESTs) in which large numbers of randomly selected cDNA clones are partially sequenced. The collection of ESTs reflects the level and complexity of gene expression in the sampled tissue. To date, the majority of plant ESTs are from nonwoody plants such as Arabidopsis, Brassica, maize, and rice. Here, we present a large-scale production of ESTs from the wood-forming tissues of two poplars, Populus tremula L. x tremuloides Michx. and Populus trichocarpa 'Trichobel.' The 5,692 ESTs analyzed represented a total of 3,719 unique transcripts for the two cDNA libraries. Putative functions could be assigned to 2,245 of these transcripts that corresponded to 820 protein functions. Of specific interest to forest biotechnology are the 4% of ESTs involved in various processes of cell wall formation, such as lignin and cellulose synthesis, 5% similar to developmental regulators and members of known signal transduction pathways, and 2% involved in hormone biosynthesis. An additional 12% of the ESTs showed no significant similarity to any other DNA or protein sequences in existing databases. The absence of these sequences from public databases may indicate a specific role for these proteins in wood formation. The cDNA libraries and the accompanying database are valuable resources for forest research directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.

[Common overuse knee-to-toes injuries in recreational exercise. Most cases are treatable in primary health care]

Although overuse injuries are common among recreational exercise-takers, in most cases they are treatable in primary care. It is important to evaluate both intrinsic and extrinsic aetiological factors underlying the development of overuse injuries. Treatment should always be focused on the aetiological factors, rather than solely on the symptoms. After an initial period of rest, a supervised rehabilitation programme, combined with correction of intrinsic and extrinsic factors, is the optimal treatment for most overuse syndromes. Surgery is only rarely necessary.

[Ligament injuries of the ankle--what happens later? Non-surgical treatment is effective in 80-90 per cent of cases]

Ligament injuries of the ankle joint are the most common sports-related injuries. In more than 90 per cent of all cases, it is a question of lateral ligament injury. The recommended acute treatment is always non-surgical, with range of motion training, followed by strengthening and co-ordination exercises. Approximately 80-90 per cent of all ligament injury patients regain normal ankle function after this form of treatment. Early active treatment can reduce time off from sports and the duration of sick leave. Residual problems, mainly pain or recurrent or chronic instability are seen in approximately 10-20 per cent of cases. In cases of chronic instability, ligament reconstruction is recommended. In patients with anterior or anterolateral ankle pain, arthroscopic resection of bone spurs or loose bodies may be beneficial.

Treatment with the spin-trap agent alpha-phenyl-N-tert-butyl nitrone does not enhance the survival of embryonic or adult dopamine neurons

Reactive oxygen species are thought to be involved in the death of dopaminergic neurons in Parkinson's disease as well as in transplanted embryonic dopaminergic neurons. The spin-trap agent alpha-phenyl-N-tert-butyl nitrone (PBN) reacts directly with radical species and may thereby prevent them from damaging important cellular molecules such as membrane lipids. We found that PBN does not increase the survival of cultured embryonic dopaminergic neurons subjected to serum deprivation, whereas the antioxidant and lipid peroxidation inhibitor lazaroid U-83836E does. Moreover, PBN does not increase the survival of grafted embryonic dopaminergic neurons or graft efficacy (monitored as changes in drug-induced motor asymmetry in hemiparkinsonian rats) when the spin-trap agent is given intraperitoneally to the graft recipient or is added to the solutions used when preparing tissue for transplantation. Another spin-trap agent, alpha-(4-pyridyl-1-oxide)-N-tert-butyl nitrone (POBN) also failed to protect neurons when given to graft recipients in the same experimental paradigm. Finally, we found that adult nigral neurons subjected to a progressive retrograde 6-OHDA lesion are not protected by systemic treatment with PBN. Even though reduction of oxidative stress by overexpression of superoxide dismutase or addition of lazaroids have previously been shown to enhance the survival of cultured and grafted dopaminergic neurons, spin-trap agents PBN and POBN do not provide protection in these experimental paradigms. This may be due to antioxidants and spin-trap agents interfering in different steps of free radical-induced cell damage.

Hydrolysis of microcrystalline cellulose by cellobiohydrolase I and endoglucanase II from Trichoderma reesei: adsorption, sugar production pattern, and synergism of the enzymes

Microcrystalline cellulose (10 g/L Avicel) was hydrolysed by two major cellulases, cellobiohydrolase I (CBH I) and endoglucanase II (EG II), of Trichoderma reesei. Two types of experiments were performed, and in both cases the enzymes were added alone and together, in equimolar mixtures. In time course studies the reaction time was varied between 3 min and 48 h at constant temperature (40 degrees C) and enzyme loading (0.16 micromol/g Avicel). In isotherm studies the enzyme loading was varied in the range of 0.08-2.56 micromol/g at 4 degrees C and 90 min. Adsorption of the enzymes and production of soluble sugars were followed by FPLC and HPLC, respectively. Adsorption started quickly (50% of maximum achieved after 3 min) but was not completed before 60-90 min. For CBH I a linear relationship was observed between the production of soluble sugars and adsorption, showing that the average activity of the bound CBH I molecules does not change with increasing saturation. For EG II the corresponding curve levelled off which is explained by initial hydrolysis of loose ends on Avicel. The enzymes competed for binding sites, binding of EG II was considerably affected by CBH I, especially at high concentration. CBH I produced more soluble sugars than EG II, except at conversions below 1%. At 40 degrees C when the enzymes were added together they produced 27-45% more soluble sugars than the sum of what they produced alone, i.e. synergistic action was observed (the final conversion after 48 h of hydrolysis was 3, 6, and 13% for EG II, CBH I, and their mixture, respectively). At 4 degrees C, on the other hand, when the conversion was below 2.5%, almost no synergism could be observed. Molar proportions of the produced sugars were rather stable for CBH I (11-15%, 82-89%, and <6% for glucose, cellobiose, and cellotriose, respectively), while it varied considerably with both time and enzyme concentration for EG II. The observed stable but high glucose to cellobiose ratio for CBH I indicates that the processivity for this enzyme is not perfect. EG II produced significant amounts of glucose, cellobiose, and cellotriose, which are not the expected products of a typical endoglucanase activity on a solid substrate. We explain this by hypothesizing that EG II may show processivity due to its extended substrate binding site and the presence of its cellulose binding domain.

Arthroscopic and open shoulder stabilization using absorbable implants. A clinical and radiographic comparison of two methods

The aim of this study was to compare the clinical and radiographic results in patients with recurrent unidirectional, post-traumatic shoulder instability (dislocations/subluxations). All the patients had a Bankart lesion and underwent reconstruction using either an open or an arthroscopic technique and absorbable implants. Thirty-three consecutive patients (36 shoulders) were operated on by one surgeon. Group A comprised 18 shoulders which underwent an open Bankart reconstruction using absorbable 3.7-mm TAG suture anchors. Group B comprised 18 shoulders which underwent a combination of an intra- and extra-articular arthroscopic stabilization using 8-mm Suretac fixators. The median number of dislocations before the reconstruction was 5(0-45) in group A and 4 (0-30) in group B (NS). The follow-up examination was performed by an independent observer after a median of 31 (range 25-38) months in group A and 28 (range 18-46) months in group B (NS). An independent radiologist without any knowledge of the surgical procedure evaluated all the radiographs. There were no re-dislocations in either group. In group A, the Rowe and Constant scores were 86 (range 61-98) and 89 (range 73-99), respectively. The corresponding values in group B were 92 (range 83-98; P = 0.05) and 96 (range 75-100; NS). The external rotation in abduction was 65 degrees (range 20 degrees-90 degrees) in group A and 83 degrees (range 65 degrees-105 degrees) in group B (P = 0.0017). The radiographs revealed that 10/18 (56%) in group A and 4/18 (23%) in group B had visible drill-holes or cystic formations in conjunction with the drill-holes (P = 0.002). In this study the open procedure resulted in a restriction in external rotation more frequently than the arthroscopic procedure. The radiographs revealed visible drill-holes or cystic formations in conjunction with the drill-holes more frequently when TAG suture anchors were used than when Suretac fixators were used. The radiographic changes did, not appear to affect the clinical outcome, however.