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Biomedical subjects

K Johansson

Publications and source records attributed to K Johansson.

At least 19 recordsLinked to original sources

Tailored vitrectomy and laser photocoagulation without scleral buckling for all primary rhegmatogenous retinal detachments.

AIM: To investigate the anatomical and functional results and the complications in eyes operated on using vitrectomy without scleral buckling for all forms of rhegmatogenous retinal detachment (RRD). METHODS: All cases of primary RRD at the University Hospital of Lund, Lund, Sweden, treated by one surgeon during a period of 3 years were retrospectively reviewed. In 131 (98%) of 134 consecutive cases, a final follow-up record of 3-14 months was obtained, and these eyes were included in the study. The surgical protocol was tailored for each case and consisted of vitrectomy, laser photocoagulation and tamponade. Preoperative and intraoperative variables were analyses for risk for redetachment and postoperative proliferative vitreoretinopathy (PVR). RESULTS: Complete reattachment was achieved in 87% of cases (114/131) after one operation and in 95% cases after > or =1 operation. A primary detachment of >1 quadrant was the only significant risk factor for redetachment (p<0.05). The most common cause of redetachment was progressive PVR. Significant risk and factors for PVR postoperatively were a poor preoperative visual acuity and a high number of laser effects during surgery (p<0.05). The visual acuity for the total number of eyes, macula-off eyes, and pseudophakic as well as phakic eyes, improved significantly. The visual acuity for macula-on eyes did not change significantly. Six patients developed ocular hypertension and another 6 an epiretinal membrane. Three patients reported a visual field defect. Increased lens opacification was seen in 64 of the 94 (68%) phakic eyes. CONCLUSIONS: The tailored vitrectomy protocol is well suited to all types of RRD. Increased lens opacification in phakic eyes is common, but visual acuity is considerably improved in phakic as well as pseudophakic eyes. PVR development postoperatively is related to the extent of laser treatment, indicating that the protocol may be even further optimised in the future.

Aged↗

Attitude changes among emergency department triage staff after conducting routine alcohol screening.

Excessive alcohol consumption is common among injury patients, but routine alcohol interventions seem to be difficult to implement in emergency departments. An obstacle seen in previous studies is the limited time available in a real-world setting for staff to participate in routine alcohol screening and interventions. In the present study, ordinary staff participated in a simple alcohol screening procedure. The aim of the study was to evaluate the feasibility of this procedure and if there was any change in attitudes and practices among triage staff after the implementation. We analyzed interviews with six staff members and questionnaires completed by 29 nurses and medical secretaries before and after a period of systematic routine screening. The staff reported that the routine worked well and that few patients reacted negatively. A positive change was seen in attitudes towards alcohol preventive measures in general. However, this seems not to be sufficient for the staff to spontaneously engage more actively. In fact, more of the staff were uncertain after the study period whether the emergency department is an appropriate place for alcohol screening and intervention despite an increased role legitimacy and perceived competence. There is a need for further development of alcohol prevention models that are acceptable for the staff to implement as part of the daily routine.

Adolescent↗

Evaluation of platelet function, a method comparison.

Platelet function can be studied using many different methods why it is of interest to understand how data from different assays relate to each other. In the present study we compare two methods suitable for screening purposes with two established although laborious methods, impedance aggregometry and platelet-rich plasma (PRP) aggregation. The alternative assays tested were: (i) exposure of active alphaIIbbeta3, in diluted whole blood and (ii) whole blood aggregation assessed by residual platelet counting. The fibrinogen receptor activation assay was found to have the lower variability, higher sensitivity to ADP, and higher signal to noise ratio compared with residual platelet counting. The sensitivity and response profile of the fibrinogen receptor activation assay and residual platelet counting were more similar to PRP aggregation than to impedance aggregometry, whereas impedance aggregometry displayed lower sensitivity to ADP. The two alternative assays correlated well with PRP aggregation as well as with each other. The fibrinogen receptor activation assay displayed the highest potency for AR-C69931MX, possibly due to a lower protein content compared with residual platelet counting. The two studied assays compare well with the more established assays, and are thus both good alternatives for platelet function testing and evaluation of new potential platelet antagonists.

Adenosine Diphosphate↗

Comparison of experimental nerve injury caused by ultrasonically activated scalpel and electrosurgery.

BACKGROUND: Iatrogenic nerve injury caused by heat from dissection instruments is a significant problem in many areas of surgery. The aim of the present study was to compare the risk of nerve injury for three different dissection instruments: monopolar and bipolar electrosurgery (ES) and an ultrasonically activated (US) instrument. METHODS: The biceps femoris muscle was cut in a standard manner just adjacent to the sciatic nerve using monopolar ES, bipolar ES or US shears. A total of 73 functional experiments were conducted in which the nerve was isolated, divided proximally, and stimulated supramaximally in 37 anaesthetized rats. The electromyographic (EMG) potential was recorded distally before and after each experiment. Nerve dysfunction was defined as more than 10 per cent loss of the evoked EMG potential. Fifty-nine nerves were examined histologically after dissection with the different instruments. The extent of heat damage was determined in four nerves that were divided with ES bipolar scissors and five that were divided with US shears. RESULTS: Reduction in the EMG potential was significantly more frequent in the monopolar ES group than in the US group. Morphological examination also showed significantly less nerve damage in the US group. CONCLUSION: US instruments may be safer than ES for dissection close to nerves.

Animals↗

Factors influencing GPs' decisions regarding screening for high alcohol consumption: a focus group study in Swedish primary care.

OBJECTIVE: The aim of this study was to explore factors that influence general practitioners' (GPs') decisions regarding screening for high alcohol consumption. METHODS: GPs working at three primary healthcare centres in Sweden participated in focus group interviews. The interviews were recorded and transcribed verbatim, and a deductive framework approach was used for the analysis. RESULTS: The majority of the participating GPs did not believe in asking all patients about their alcohol consumption. Reported factors that influenced how many and which patients were questioned about alcohol consumption were time, age of the patient, consultation setting, patient-physician relationship, what symptoms the patient presented with, and knowledge of measures if patients appear to have a high alcohol consumption. Thus, alcohol screening and intervention were not performed in all patient groups as was originally intended, but were performed in limited groups of patients such as those with alcohol-related symptoms. CONCLUSIONS: Although the number of participants in this study was small and the conclusions cannot be generalized, the results provide some valuable insights into why GPs are hesitant to engage in screening for high alcohol consumption. Since prevention of alcohol-related health problems is an important public health issue, many different screening and intervention strategies have to be formulated and evaluated in order to reach patients with both hazardous and harmful alcohol consumption within the healthcare system. Screening all consecutive patients for a limited period or screening patient groups known to include a fairly high frequency of high alcohol consumers are two ways of limiting the time requirements and increasing role legitimacy. Still, there is a need for a broader public health strategy involving many players in the community in alcohol preventive measures, especially in more primary preventive approaches.

Alcohol Drinking↗

Low intensity resistance exercise for breast cancer patients with arm lymphedema with or without compression sleeve.

Clinical trials of the effect of physical exercise on breast cancer related arm lymphedema (ALE) are very rare. The aim of this study was to examine if controlled low intensity arm exercises with weights, with or without a compression sleeve, influence breast cancer related ALE. Thirty-one breast cancer treated patients with small or moderate ALE were included in the study. A specifically designed arm exercise program was performed with or without compression sleeve on different days and in a randomized order. Measurements were performed before, directly after and 24 hours after the exercise intervention, with water displacement method and multiple frequency bioelectrical impedance analysis (n=10) for volume of the arms and Borg's scale for perceived exertion during training. There was an increase of total arm volume of the lymphedema arm immediately after the exercise intervention for both with and without sleeve conditions (p < 0.01). At 24 hours, no volume increase was found compared to pre-exercise and both groups showed tendency towards reduced lymphedema relative volume (p < 0.05). The patient's rating of perceived exertion was low regardless of whether a sleeve was worn, but was significantly higher when exercising with the sleeve. We conclude that low intensity exercises can be performed by patients with arm lymphedema without risk of worsening the edema. Exercises without the sleeve may be of benefit provided compression sleeve is worn regularly.

Adult↗

Genetic parameters for calving difficulty, stillbirth, and birth weight for Hereford and Charolais at first and later parities.

The aim of this study was to estimate direct and maternal genetic parameters for calving difficulty score, stillbirth, and birth weight at first and later parities for Charolais and Hereford cattle in Sweden. Calving traits have long been recorded for pure-bred beef cattle in Sweden, but only birth weight has been used in the selection in order to avoid calving difficulties. Linear animal model analyses included records on birth weight for 60,309 Charolais and 30,789 Hereford calves born from 1980 to 1999, and calving traits for 74,538 Charolais and 37,077 Hereford calves born from 1980 to 2001. The frequencies of difficult calvings and stillbirths were approximately 6% at first and 1 to 2% at later parities for both breeds. Fewer than half the stillborn calves were born from difficult calvings. Heritabilities estimated for birth weight in different univariate and bivariate analyses for Charolais and Hereford calves born at first and later parities ranged from 0.44 to 0.51 for direct effects and 0.06 to 0.15 for maternal effects. Heritabilities on the observable scale for calving difficulty score of Charolais and Hereford, scored in three classes, ranged from 0.11 to 0.16 for direct and 0.07 to 0.12 for maternal effects at first parity, and lower at later parities. All estimated heritabilities for stillbirth were very low (0.002 to 0.016 on the observable scale). Direct-maternal genetic correlations were negative, with few exceptions. Genetic correlations between the traits and between parities within traits were generally moderate to high and positive. Calving difficulty score should be included in the genetic evaluation of beef breeds in Sweden, whereas progeny groups in Swedish beef populations are too small for stillbirth to be considered directly.

Animals↗

Genetic relationships between calving and carcass traits for Charolais and Hereford cattle in Sweden.

The objective of this study was to estimate genetic correlations between calving difficulty score and carcass traits in Charolais and Hereford cattle, treating first and later parity calvings as different traits. Genetic correlations between birth weight and carcass traits were also estimated. Field data on 59,182 Charolais and 27,051 Hereford calvings, and carcass traits of 5,260 Charolais and 1,232 Hereford bulls, were used in bivariate linear animal model analyses. Estimated heritabilities were moderate to high (0.22 to 0.50) for direct effects on birth weight, carcass weight, and (S)EUROP (European Community scale for carcass classification) grades for carcass fleshiness and fatness. Heritabilities of 0.07 to 0.18 were estimated for maternal effect on birth weight, and for direct and maternal effects on calving difficulty score at first parity. Lower heritabilities (0.01 to 0.05) were estimated for calving difficulty score at later parities. Carcass weight was positively genetically correlated (0.11 to 0.53) with both direct and maternal effects on birth weight and with direct effects on calving difficulty score. Carcass weight was, however, weakly or negatively (-0.70 to 0.07) correlated with maternal calving difficulty score. Higher carcass fatness grade was genetically associated with lower birth weight, and in most cases, also with less difficult calving. Genetic correlations with carcass fleshiness grade were highly variable. Moderately unfavorable correlations between carcass fleshiness grade and maternal calving difficulty score at first parity were estimated for both Charolais (0.42) and Hereford (0.54). This study found certain antagonistic genetic relationships between calving performance and carcass traits for both Charolais and Hereford cattle. Both direct and maternal calving performance, as well as carcass traits, should be included in the breeding goal and selected for in beef breeds.

Animals↗

Breast cancer patients' experiences of lymphoedema.

The aim of this study was to explore employed women's experiences of light or moderate arm lymphoedema following breast cancer treatment in order to gain a deeper understanding of this phenomenon. Twelve women took part in a semistructured interview. A qualitative method with a phenomenological approach was applied to analyse data. In order to integrate the experiences in the everyday life of the women, a critical incident method was used. The findings indicate that there are many different practical and psychosocial problems related to arm lymphoedema. Three main themes were common to all the women. These themes were: (i) Attitudes from people in their surroundings, including reactions to the problem from other people and reactions from the women on the attitudes of other people. (ii) Discovery and understanding of oedema as a chronic disease and its treatment. (iii) Coping, including both problem-focused and emotion-focused strategies. The problems integrated in daily life were of low frequency but of considerable importance to the women. In conclusion, it is of great importance that health care professionals should be aware of and have knowledge about these problems. The women's needs for expressing their experiences of arm lymphoedema may be encouraged at the time of discovery and then regularly as long as the women seek care. Efforts may be made to strengthen the women's coping skills, eventually in a multidisciplinary approach. The interaction skills of health care professionals are probably of great importance in strengthening the resources of the women leading to a positive outcome.

Activities of Daily Living↗

Genetic relations of yolk proportion and chick weight with production traits in a White Leghorn line.

1. The main purpose of this study was to estimate genetic correlations between yolk proportion, chick weight and production traits using an animal model. 2. Direct-direct genetic correlations were estimated between yolk proportion and age at first egg (-0.34), body weight at 20 (0.10), 40 (0.58) and 60 (0.52) weeks of age, egg number (0.56), egg mass (0.59), feed intake (0.64) and feed conversion (-0.25). 3. Maternal-direct genetic correlations were estimated between chick weight and age at first egg (0.40), body weight at 20 (0.57), 40 (0.66) and 60 (0.56) weeks of age, egg number (-0.50), egg mass (0.21), feed intake (0.45) and feed conversion (0.17), respectively. 4. In conclusion, the results suggest that selection on a higher yolk proportion would not have any unfavourable effects on egg production. Maternal-direct genetic correlations between chick weight and production traits resembled direct-direct genetic correlations between egg weight and production traits found in other studies.

Age Factors↗

Genetic correlations between the maternal genetic effect on chick weight and the direct genetic effects on egg composition traits in a White Leghorn line.

Selection can be a useful way to alter yolk proportion and thereby egg dry matter which, owing to its economic importance, is a trait of substantial importance for the egg-processing industry. However, the egg is primarily the chamber of embryonic development. The main purpose of this study was to estimate genetic correlations between the maternal effect on chick weight at hatching and the direct effect on different egg composition traits, in particular, yolk proportion. Additionally, genetic parameters were estimated for egg composition traits. To create a data set suitable for estimation of genetic parameters, a three-round selection experiment was set up. Birds were selected based on their predicted breeding values for the genetic maternal effect on chick weight and the direct genetic effect on yolk proportion according to the theory of elliptical selection. Genetic parameters were estimated using a multiple trait animal model and restricted maximum likelihood. The maternal heritability for chick weight was 0.5, whereas the direct heritability was dose to 0. The genetic correlations between the maternal effect on chick weight and the direct effect on yolk proportion, yolk weight, albumen weight, albumen dry matter concentration, and egg weight were 0.14, 0.76, 0.93, 0.14, and 0.99, respectively. The heritabilities for yolk proportion, yolk weight, albumen weight, albumen dry matter concentration, and egg weight were 0.33, 0.43, 0.57, 0.38, and 0.60, respectively. We conclude that breeding ought to be a useful way to increase egg dry matter with no expected unfavorable correlated effects on chick weight.

Analysis of Variance↗

Genetic effects on stillbirth and calving difficulty in Swedish Holsteins at first and second calving.

In Swedish Holstein dairy cattle, genetic effects on stillbirth and calving difficulty were studied in 411,409 first- and 281,193 second-calvers. A linear single-trait sire-maternal grandsire model and a threshold model using a Gibbs sampling technique were used to analyse calving data from 1985 to 1996. In first calving when using the linear model, the heritability of stillbirth on the visible scale was 4% for the direct effect and 3% for the maternal effect. For calving difficulty it was 6% and 5% for direct and maternal effects, respectively. In second calving the corresponding heritabilities for the two traits were considerably lower, less than 1%. Adjusting for calving difficulty in linear analysis of stillbirth halved the heritabilities for the direct and maternal effects in first calving. When using a threshold model, heritabilities for stillbirth in first-calvers were 12% and 8% for direct and maternal effects, respectively, and for calving difficulty they were 17% and 12%. At second calving corresponding heritabilities were 2 to 4% for stillbirth and 4 to 7% for calving difficulty. The correlation between direct and maternal effects was around -0.1, irrespective of whether the linear or the threshold model was used for first-calvers. The genetic correlations between bulls' EBV from first and second calving were 0.4 to 0.5 for direct and maternal effects in stillbirth, whereas they were 0.6 to 0.7 for calving difficulty. In first-calvers there was a substantial genetic variation in both traits, expressed by differences between breeding values of bulls, despite fairly low heritability. The results obtained in this study suggest that first-parity records should preferably be used for genetic evaluation of bulls for calving performance. In such routine evaluations both stillbirth and calving difficulty, and both direct and maternal effects, should be included.

Animals↗

Structure and function of cellular deoxyribonucleoside kinases.

Deoxyribonucleoside kinases phosphorylate deoxyribonucleosides, a crucial reaction in biosynthesis of DNA precursors through the salvage pathway. Their medical interest stems from their activation of a number of anticancer and antiviral drugs such as 2-chloro-2'-deoxyadenosine, azidothymidine and acyclovir. Here we review what is presently known about each of the mammalian kinases as well as some other members of the deoxyribonucleoside kinase family. A description of the biochemical properties of the enzymes is followed by an overview of the structural studies made on this family of enzymes, including the catalytic mechanism as well as the mechanism for feedback inhibition. A presentation of homology models of other proteins in the family is made and, finally, the determinants of substrate and substrate analog specificities are described.

Amino Acid Sequence↗

Factors associated with the development of arm lymphedema following breast cancer treatment: a match pair case-control study.

We examined factors that may influence the development of arm lymphedema following breast cancer treatment including the specific mode of therapy, patient occupation and life style. Medical record data and a questionnaire were used to collect information after surgery concerning such issues as wound seroma, infection, adjuvant treatment, vessel string (phlebitis), body mass index, smoking habits and stress. Occupational workload was assessed after surgery whereas housework, exercise, hobbies and body weight were assessed both before and after surgery. Seventy-one breast cancer treated women with arm lymphedema lasting more than 6 months but less than 2 years were matched to women similarly treated for breast cancer but without arm lymphedema (controls). The matching factors included axillary node status, time after axillary dissection, and age. In the lymphedema group, there was a higher body mass index at time of surgery (p=0.03) as well at time of study (p=0.04). No differences were found in occupational workload (n=38) or housework, but the lymphedema group reduced their spare time activities including exercise after surgery compared with the controls (p<0.01). In conclusion, women treated for breast cancer with axillary node dissection with or without adjuvant radiotherapy could maintain their level of physical activity and occupational workload after treatment without an added risk of developing arm lymphedema. On the other hand, a higher BMI before and after operation increases the lymphedema risk.

Arm↗

Developmental expression of DCC in the rat retina.

The protein product of the deleted in colorectal cancer (DCC) gene possesses netrin-binding activity and may be involved in axonal guidance during retinal development. The temporal and spatial expression of DCC was analyzed in developing rat retina by means of immunoblotting and immunohistochemistry as well as by reverse transcription-polymerase chain reaction. Transient DCC protein expression is evident on ganglion cell axons in embryonic and neonatal retina. Double labeling experiments demonstrate DCC immunolabeling on processes that stratify in the inner plexiform layer and are derived from cholinergic amacrine cells. This pattern is maintained during the early postnatal period. DCC immunolabeling in the inner plexiform layer declines with age and is not observed in adult retina. The down-regulation of the DCC protein is confirmed by Western blot analysis. mRNA for DCC is expressed in embryonic, postnatal and adult retina and shows no correlation with the protein down-regulation. We suggest that DCC expression may be correlated with the functional segregation of the inner plexiform layer.

Animals↗