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Biomedical subjects

J Karlsson

Publications and source records attributed to J Karlsson.

At least 109 records · Page 6Linked to original sources
PubMed1998

A novel alpha-type carbonic anhydrase associated with the thylakoid membrane in Chlamydomonas reinhardtii is required for growth at ambient CO2.

A 29.5 kDa intracellular alpha-type carbonic anhydrase, designated Cah3, from the unicellular green alga Chlamydomonas reinhardtii is the first of this type discovered inside a photosynthetic eukaryote cell. We describe the cloning of a cDNA which encodes the protein. Immunoblot studies with specific antibodies raised against Cah3 demonstrate that the polypeptide is associated exclusively with the thylakoid membrane. The putative transit peptide suggests that Cah3 is directed to the thylakoid lumen, which is confirmed further by the presence of mature sized Cah3 after thermolysin treatment of intact thylakoids. Complementation of the high inorganic carbon concentration-requiring mutant, cia-3, with a subcloned cosmid containing the cah3 gene yielded transformants that grew on atmospheric levels of CO2 (0.035%) and contained an active 29.5 kDa alpha-type carbonic anhydrase. Although, cia-3 has reduced internal carbonic anhydrase activity, unexpectedly the level of Cah3 was similar to that of the wild-type, suggesting that the mutant accumulates an inactive Cah3 polypeptide. Genomic sequence analysis of the mutant revealed two amino acid changes in the transit peptide. Results from photosynthesis and chlorophyll a fluorescence parameter measurements show that the cia-3 mutant is photosynthetically impaired. Our results indicate that the carbonic anhydrase, extrinsically located within the chloroplast thylakoid lumen, is essential for growth of C.reinhardtii at ambient levels of CO2, and that at these CO2 concentrations the enzyme is required for optimal photosystem II photochemistry.

Amino Acid Sequence↗
PubMed1998

MK-801 does not enhance dopaminergic cell survival in embryonic nigral grafts.

Two groups of hemiparkinsonian rats received grafts of embryonic ventral mesencephalon with or without the addition of the NMDA receptor antagonist (+)dizocilpine hydrogen maleate (MK-801). When added to the cell suspension, a 10 microM concentration of MK-801 did not enhance the survival of tyrosine hydroxylase positive neurones in the grafts. These findings suggest that cell death occurring during nigral transplantation is not primarily due to excitotoxicity.

Animals↗
PubMed1998

The immune modulator Linomide prevents neuronal death in injured peripheral nerves of the mouse.

Neuronal death after injury or disease could result from imbalanced cytokine expression. Linomide (LS-2616, quinoline-3-carboxamide), a synthetic immunomodulator with effects on cytokine production, suppresses autoimmune diseases of the nervous system. Here adult mice were pre-treated with 200 mg/kg/day of Linomide for 9 days, after which the sciatic nerves were crushed. After another 10 days of Linomide treatment the dorsal root ganglia were dissected out and stained for apoptosis, either immediately or after 2 days in culture, which increases cell death. Superior cervical ganglia were also cultured for 2 days. The Linomide pretreatment profoundly reduced (approximately 60-80%) the injury-induced apoptotic death of neurons and satellite cells in both systems. The results suggest that modulation of the inflammatory cytokine cascade is a promising road to nerve cell rescue.

Adjuvants, Immunologic↗
PubMed1998

Closing patellar tendon defects after anterior cruciate ligament reconstruction: absence of any benefit.

The most common graft in anterior cruciate ligament (ACL) surgery involves using the central one-third of the patellar tendon. Knowledge concerning the postoperative disability after harvesting the patellar tendon is, however, limited. The aim of this study was to evaluate the impact patellar tendon suture and bone grafting of the patellar bone defect might have in terms of functional outcome and patellofemoral pain after harvesting the bone-tendon-bone graft, compared with leaving the harvested site non-sutured and non-grafted. Sixty patients, scheduled for arthroscopically assisted ACL reconstruction, were randomly allocated to two groups. In group I, suture of the patellar tendon and bone grafting of the patellar defect were performed. In group II, the tendon gap and the patellar defect were left open. Preoperatively, there was no significant difference between the groups when comparing objective knee stability, as measured with a KT-1000 laxity meter, Lysholm score, Tegner activity level, IKDC score, or patello-femoral pain score. Both groups had a significantly improved Lysholm score at the 2-year follow-up, without any difference between them. Tegner's activity level was significantly lower at follow-up, compared with the pre-injury level in both groups. The patellofemoral pain score improved significantly after the reconstruction, without any difference between the groups. Ultrasonography did not reveal any difference between the groups in terms of healing of the tendon gap. This study revealed no differences in donor site morbidity, functional outcome, patellofemoral pain score or knee joint stability between the two treatment groups. The conclusion is that suture of the patellar tendon and bone grafting of the patellar defect do not improve the functional results or reduce donor site morbidity after arthroscopically assisted ACL.

Adolescent↗
PubMed1998

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.

Adolescent↗
PubMed1998

Analgesic effects of intra-articular morphine during and after knee arthroscopy: a comparison of two methods.

The objective of this study was to compare the analgesic effects of intra-articularly administered bupivacaine with bupivacaine/morphine during and after therapeutic knee arthroscopy. In a prospective, randomized study, 50 patients with clinical signs of medial meniscal injury were allocated to two groups, A and B. The patients in group A received 40 mL of 0.25% bupivacaine while the same dose of bupivacaine combined with 1 mg of morphine sulphate was administered in group B. Pain was estimated using the visual analogue scale (VAS) during surgery and at 2, 4, 6, and 24 hours after the operation was completed. Supplementary analgesic requirements were also registered, as well as the patients' overall rating of the entire procedure. The pain scores were significantly lower in Group B throughout the whole postoperative observation period. However, no significant differences were found between the two groups in terms of intraoperative pain scores, supplementary analgesic requirements, or the overall rating of the procedure. This study provides evidence that arthroscopic surgery can be performed in a safe manner after intra-articularly administered bupivacaine with or without low-dose morphine. The combination of low-dose morphine and bupivacaine did, however, produce a superior postoperative analgesic effect during the 24 hours following knee arthroscopy compared with bupivacaine alone.

Adult↗
PubMed1998

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.

Adult↗
PubMed1998

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.

Adolescent↗
PubMed1998

Muscle metabolism and quality (MQI) in prediabetic sedentary man.

Twelve pairs of healthy sedentary males matched for their body mass index (BMI) with either a low insulin response (LIR; a stage of prediabetes) or a high (HIR; controls) to a standardized glucose infusion test (GIT) were studied in respect to their exercise capacities (W(OBLA), W(SL) and relative W(OBLA):W(OBLA) x W(SL)(-10 x 100), muscle fiber composition (%ST), muscle citrate synthase activity (CS), muscle ubiquinone (MUQ), MUQ over %ST (muscle quality index, MQI), and peripheral insulin sensitivity (PIS) as described with insulin-clamp techniques (SIGITmean). LIR and HIR displayed normal PIS and positive relationships versus exercise capacity. LIR's but not HIR's relative W(OBLA) was related to CS as earlier only documented in endurance athletes but at a lower level than in athletes. This pointed at a poor peripheral oxygen delivery in LIR. LIR's MQI decreased relative to HIR's the higher the muscle CS indicating radical related muscle trauma in LIR as in athletes. LIR representing prediabetes described muscle anomalies, which could represent prestages of the lesions observed in type-2 diabetes. They are claimed to be responsible for insulin-, glucose-, lipid-resistance, and peripheral circulatory resistance.

Adult↗
PubMed1998

Swedish obese subjects (SOS)--an intervention study of obesity. Two-year follow-up of health-related quality of life (HRQL) and eating behavior after gastric surgery for severe obesity.

OBJECTIVE: To examine the effects of weight loss on health-related quality of life (HRQL) in subjects with severe obesity. DESIGN: Controlled clinical trial of the outcomes of surgical vs conventional weight reduction treatment. SUBJECTS: The first 487 surgical cases and their conventionally treated, matched controls were followed for two years in the Swedish Obese Subjects (SOS) intervention study. MEASUREMENTS: A battery of generic and study-specific self-assessment instruments or subscales was used to characterize HRQL in the severely obese (BMI) > or = 34 kg/m2 for males and BMI > or = 38 kg/m2 for females). Measures of general health perceptions (general health rating index; current health), mental well-being (mood adjective check list; pleasantness, activation and calmness), mood disorders (hospital anxiety and depression scale; anxiety and depression) and social interaction (sickness impact profile), were supplemented by obesity-specific modules on obesity-related psychosocial problems and eating behavior (three-factor eating questionnaire; restrained eating, disinhibition and perceived hunger). Assessments were conducted prior to treatment and repeated after 6, 12 and 24 months. RESULTS: Poor HRQL before intervention was dramatically improved after gastric restriction surgery, while only minor fluctuations in HRQL scores were observed in the conventionally treated controls. Peak values were observed in the surgical group at 6 or 12 months after intervention with a slight to moderate decrease at the two-year follow-up. The positive changes in HRQL after two years were related to the magnitude of weight loss, that is, the greater the weight reduction, the greater the HRQL improvements. Eating behavior improved accordingly. CONCLUSION: Quality of life in the severely obese is improved by substantial weight loss. Most patients benefit from weight reduction surgery, while HRQL in surgical patients with minor reduction in overweight is less positive. Further research is needed to determine outcome predictors of the surgical management of severe obesity and to ensure that HRQL improvements are maintained.

Cohort Studies↗
PubMed1998

Subtalar instability of the foot. A review and results after surgical treatment.

Most subtalar ligamentous injuries occur in combination with ankle ligament injuries, but the exact aetiology and the true incidence remain unknown. The aim of this study was to review the problem, propose a definition and to analyze the results of an anatomic reconstructive surgical technique in the treatment of subtalar instability. Twenty-two patients suffering from chronic subtalar instability of the foot were operated with anatomical reconstruction. The cervical, the lateral talo-calcaneal and the calcaneo-fibular ligaments were imbricated and reinforced with the lateral root of the inferior extensor retinaculum. After a minimum of 2 years follow-up the functional results were excellent or good in 18 of 22 (82%) patients and fair or poor in 4 of 22 (18%). All of the patients with unsatisfactory results suffered from residual ankle pain, two of whom also had residual instability. No reoperations have been performed. Surgical complications were seen in three patients, all minor nerve injuries of the lateral branch of the superficial peroneal nerve. These complications had no bearing on the functional results, however. This procedure was found to be feasible in patients with chronic subtalar instability.

Adult↗
PubMed1998

Surgical treatment of concomitant chronic ankle instability and longitudinal rupture of the peroneus brevis tendon.

Chronic lateral ankle instability can be associated with a longitudinal rupture of the peroneus brevis tendon. Patients with these problems have atypical posterolateral or retromalleolar pain, as well as clinical signs of ligamentous instability. This injury is frequently concomitant with lateral ligament injuries and the injury mechanism is similar; however, the tendon rupture is often missed. Laxity or insufficiency of the superior peroneal retinaculum allows the anterior part of the peroneus brevis tendon to ride upon the sharp posterior fibular edge, resulting in a longitudinal rupture of the tendon. We report on the results after surgical treatment in nine patients (10 ankles) with combined instability of the lateral ankle ligaments and longitudinal rupture of the peroneus brevis tendon. All these patients underwent surgical repair of the peroneus tendon, reconstruction of the superior peroneal retinaculum, removal of the sharp posterior edge of the fibula and correction of the ligamentous instability of the anterior talofibular and calcaneofibular ligaments. One constant finding at surgery was a longitudinal intratendineal rupture of the peroneus brevis tendon combined with insufficiency of the superior peroneal retinaculum and insufficiency of the lateral ligaments. At follow-up 3 (2-5) years post-operatively, the functional results were excellent or good in nine ankles and fair in one. All the patients with excellent or good results had resumed their preinjury activity level. We conclude that this lesion should be suspected in patients with lateral ligamentous instability, combined with retromalleolar pain. In these cases, it is important to address both the tendon rupture and the ligamentous insufficiency.

Adolescent↗
PubMed1998

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.

Absorbable Implants↗
PubMed1998

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.

Absorptiometry, Photon↗
PubMed1997

Dietary intake in relation to restrained eating, disinhibition, and hunger in obese and nonobese Swedish women.

The aims of this study were to: describe dietary intakes of obese and nonobese middle-aged women using a validated food frequency questionnaire; to assess dietary restraint, disinhibition, and hunger by the three factor eating questionnaire (TFEQ) in obese and nonobese samples and determine which of the factors are independently associated with obesity; and to examine correlations between selected nutritional variables and the TFEQ factors. Subjects studied included 179 obese Swedish women (BMI > 32) and 147 nonobese population-based controls (BMI < 28). Age-adjusted mean energy intake was significantly higher in obese women (2730 +/- 78 vs. 2025 +/- 85 kcal, p < 0.0001). In absolute and relative terms, fat intake was higher and alcohol intake was lower in the obese subjects. Disinhibition was the strongest TFEQ factor independently differentiating the obese and nonobese states, i.e., after adjustment for restraint and hunger. Within the obese sample, strong associations were seen between energy intake and disinhibition (p = 0.0005) and hunger (p = 0.0004). The association between energy intake and restrained eating was negative and weaker (p = 0.04). No such associations were seen in nonobese women. Thus, using a dietary instrument that is valid and unbiased with respect to obesity, strong psychological correlates, possibly causal, of variability in energy intake were detected in middle-aged women with obesity. Disinhibition is associated with both obesity and high-energy intakes and is therefore an important factor to consider in the treatment of women with obesity.

Adult↗
PubMed1997

Does a single device prevent further slipping of the epiphysis in children with slipped capital femoral epiphysis?

All 170 patients (212 hips) treated between 1946 and 1992 for slipped capital femoral epiphysis (SCFE) with fixation in situ with a single device were reviewed to evaluate the incidence of further slipping of the epiphysis after primary treatment. In 154 hips, a smooth device without anchorage in the epiphysis was used and in 58, a device anchored in the epiphysis. In 3 hips, further slipping of the epiphysis occurred after primary treatment with no obvious cause. In 10 hips, an obvious cause for further slipping of the epiphysis was found. These 10 hips were re-operated due to the loss of epiphyseal grip in 6 hips, unsatisfactory placement of the device in 1, while in the remaining 3 hips, the device was removed before physeal closure. Twenty-six hips (12.3%) were re-operated because the device had lost its epiphyseal grip before physeal closure, and in 25 of these hips the device was smooth and had no anchorage in the epiphysis. The conclusion of this study is that a single device with anchorage in the epiphysis is stable enough to prevent further slipping of the epiphysis in hips with SCFE.

Adolescent↗