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Biomedical subjects

S Werner

Publications and source records attributed to S Werner.

At least 37 records · Page 2Linked to original sources

The effect of dance training on joint mobility, muscle flexibility, speed and agility in young cross-country skiers--a prospective controlled intervention study.

We evaluated a short-term (3 months) and a long-term (8 months) effect of dance training on joint mobility and muscle flexibility of the spine, hip and ankle and on speed and agility in young cross-country skiers. Twenty elite cross-country skiers - aged 12-15 years - participated in the study. Five males and five females received dance training (intervention group) and five males and five females did not dance (reference group). Joint mobility and muscle flexibility of the spine, hip and ankle joints were measured using a goniometer, a kyphometer, a measuring tape and a ruler. Two sports-related functional tests - the slalom-test and the hurdle-test - were also performed. These measurements/tests were performed before the start of the dancing period and after 3 and 8 months. The subjects from the intervention group increased their speed with 0.3 s after 3 (P = 0.05) and 8 months (P = 0.02), respectively, when measured with the slalom-test. They also improved their speed and agility according to the hurdle-test after 3 months with 0.8 s (P = 0.000) and 8 months with 0.6 s (P = 0.01). Furthermore, they increased flexion-extension of the thoracic spine with 7.5 degrees after 3 months (P = 0.05) and with 9 degrees degrees after 8 months (P = 0.03) and lateral flexion of the spine with 0.04 m (P = 0.005) and 0.03 m (P = 0.02) after 3 and 8 months, respectively. The reference group was impaired or unchanged in the studied parameters after both 3 and 8 months. We conclude that dance training has a positive effect on speed and agility and on joint mobility and muscle flexibility in flexion-extension and lateral flexion of the spine in young cross-country skiers.

Adolescent↗

The effect of exercise regimens on reflex response time of the vasti muscles in patients with anterior knee pain: a prospective randomized intervention study.

The purpose of this prospective randomized intervention study was to evaluate the effect of two exercise protocols on reflex response time of vastus medialis obliquus (VMO), vastus lateralis (VL), in patients with anterior knee pain. Sixty patients were randomized into a 5-week treatment program, which consisted of only open kinetic chain tonification exercises (group I) (n = 30), or only closed kinetic chain tonification exercises (group II) (n = 30). Assessment of an aspect of neuromotor control was obtained by measuring the reflex response times of VMO and VL at the time of initial clinical examination, at the end of the exercise period (five weeks), and three months after the completion of the exercise period. At these evaluation occasions, the intensity and the number of times that the patients experienced anterior knee pain during daily life was recorded on a Visual Analog Scale (VAS). No alterations in reflex response times of VMO and VL were observed in either group. Changes of anterior knee pain over time were statistically significant in both groups. Only small and not statistically supported differences in anterior knee pain were found between the two groups. These results suggest that the reflex response times of the two vasti muscles can not be altered after a five week open or closed kinetic chain exercise program. In contrast, knee pain decreased significantly in both groups.

Exercise Therapy↗

Dynamics and localization of activin A expression in rat gastric ulcers.

BACKGROUND: Activin A, the homodimer of the activin/inhibin betaA subunit, has been shown to participate in cutaneous wound healing. In this study we intended to determine its part in gastric ulceration. METHODS: Activin A expression was studied by immunohistochemistry and in situ hybridization in acetic-acid-induced chronic gastric ulcers in rat. The dynamics of this process were also assessed by quantitative real time RT-PCR and RNase protection assays (RPA). The effects of different doses of this cytokine on epithelial and mesenchymal cell proliferation were quantitated in vitro. RESULTS: Low amounts of activin A and its mRNA were expressed by epithelia, endothelia and fibroblasts in intact gastric tissue. Granulation tissue of gastric ulcers and gastric glands adjacent to the ulcer rim expressed markedly increased amounts of activin protein as well as activin/inhibin betaA mRNA. RPA and RT-PCR studies revealed a more than 3-fold increase in the relative abundance of this mRNA. Activin A did not affect the proliferation rate of fibroblasts and epithelial cells in vitro. CONCLUSIONS: Activin A participates in gastric ulcer healing in a similar fashion as in cutaneous wounding. Its expression on protein and mRNA level is markedly increased in ulcer base and rim.

Activins↗

The hazards of kissing when you are food allergic. A survey on the occurrence of kiss-induced allergic reactions among 1139 patients with self-reported food hypersensitivity.

BACKGROUND: According to a few case reports, kissing can induce symptoms due to food allergy. OBJECTIVE: We wanted to investigate the occurrence of kiss-induced allergic symptoms and other social inconveniences among patients with self-reported food hypersensitivity. METHODS: A questionnaire was answered by 1139 patients (1-84 years old, mean age 29 years, 393 males and 746 females) who considered themselves to be food allergic. RESULTS: 12% of the patients experienced allergic symptoms when in close contact with (e.g., kissing) a person who had eaten a nontolerated food prior to the contact. Some case histories suggested that the symptoms only appeared if the food intake had occurred immediately before the kiss. In addition, the questionnaires showed that 55% had problems in daily life finding tolerable food, 44% were afraid of a severe reaction from eating nontolerated food, 13% could experience symptoms when sitting beside a person who was eating such a food, and 17% could experience symptoms in the kitchen when someone else was preparing such food. CONCLUSIONS: What other people eat can influence the quality of life of food-allergic patients.

Adolescent↗

Pressure-induced phase transitions of piezoelectric single crystals from the langasite family: La3Nb0.5Ga5.5O14 and La3Ta0.5Ga5.5O14.

The hydrostatic compression of piezoelectric single crystals of La(3)Nb(0.5)Ga(5.5)O(14) (LNG) and La(3)Ta(0.5)Ga(5.5)O(14) (LTG) was studied at pressures of up to 23 GPa in diamond-anvil high-pressure cells using single-crystal X-ray diffraction techniques. The reflection-intensity data for LNG and LTG were collected at pressures of up to 22.8 GPa and 16.7 GPa, respectively. Both compounds show anisotropic behaviour under pressure, which is caused by differences in bonding parallel to the a and c directions. The compression of strongly rigid structures leads to increasing internal strains and results, at pressures of 12.4 (3) GPa for LNG and 11.7 (3) GPa for LTG, in a transition to lower symmetry. The compressibilities along the c axis are almost the same for LNG and LTG through the whole investigated pressure range. In contrast, the pressure dependencies of the a axis of these materials are similar only for the initial phase, and the axial compressibilities for the high-pressure polymorphs of LNG and LTG are significantly different to each other. The volume compressibilities of trigonal LNG and LTG (space group P321) are about 0.007 GPa(-1); respective bulk moduli are 145 (3) GPa and 144 (2) GPa. The monoclinic high-pressure phases (space group A2) of LNG and LTG show differing compressions, which can be explained by the substitution of Ta(5+) for Nb(5+). Thus, the bulk moduli for the high-pressure polymorphs of LNG and LTG are B(0) = 93 (2) GPa and B(0) = 128 (12) GPa, respectively. The volume compressibilities of the high-pressure phases at 0.011 GPa(-1) for LNG and 0.008 GPa(-1) for LTG are higher than the initial phases, this effect being more pronounced in the case of LNG.

Journal Article↗

Anterior cruciate ligament injuries in young females playing soccer at senior levels.

The aim of this investigation was to study the consequences of anterior cruciate ligament injuries in female soccer players. Special interest was focused on young female soccer players (< 16 years) sustaining anterior cruciate ligament injuries when playing at a senior level, which means playing together with players 19 years or older. In Sweden, all players belonging to an organized soccer club are insured by the same insurance company, the Folksam Insurance Company. Data of all soccer-related knee injuries in females reported to the Folksam Insurance Company between 1994 and 1998 were collected. A questionnaire was sent to 978 females who were registered to have sustained a knee injury before the age of 20 years. The response rate was 79%. Three hundred and ninety-eight female soccer players who had sustained an anterior cruciate ligament injury before the age of 19 years were analysed. Most of their anterior cruciate ligament injuries had been diagnosed using arthroscopy or magnetic resonance imaging (84%). Thirty-eight percent of the players had been injured before the age of 16 years. Of these, 39% were injured when playing in senior teams. When playing in senior teams 59% of the players below the age of 16 years and 44% of the players 16 years or older sustained their ACL injuries during contact situations. At the time of this investigation (2-7 years after the anterior cruciate ligament injury), altogether 78% (n = 311) reported that they had stopped playing soccer. The most common reason (80%) was symptoms from their anterior cruciate ligament-injured knee. It appears that many young female soccer players injure their anterior cruciate ligament when playing at a senior level. Therefore, we suggest that female soccer players under the age of 16 years should be allowed to participate only in practice sessions but not games at a senior level.

Adolescent↗

The incidence of atopic dermatitis in school entrants is associated with individual life-style factors but not with local environmental factors in Hannover, Germany.

BACKGROUND: Atopic dermatitis (AD) is a common skin disease in childhood. Micro- and macro-environmental factors have not yet been studied simultaneously in a large cohort of the same area in detail. OBJECTIVES: The incidence of AD was investigated in 97% of all school entrants (n = 4219) in the city of Hannover, Germany, with regard to the influence of individual and environmental factors. METHODS: A standardized questionnaire based on the criteria of Hanifin and Rajka that has the sensitivity and specificity of 97% compared with the clinical diagnosis of a dermatologist and a logistic regression model were used. Multiple local-based environmental factors were analysed for all 49 city quarters. RESULTS: Of all children studied, 10.5% suffered from AD at some time in their lives. The frequency of AD was significantly increasing with more privileged socio-economic status (P < 0.01). Independent factors that were associated with a higher frequency of AD were German nationality (12.4% AD compared with 2.1% in non-German), higher paternal socio-economic status (i.e. father's profession), higher daily duration of the fathers' professional work and the lack of paternal shift work. In contrast, there was no significant association between the frequency of AD and local environmental factors such as the biological effective level of air pollution and urbanization. CONCLUSIONS: In conclusion, we confirm an association between a privileged life-style and a higher incidence of AD in a large number of investigated children between 5 and 9 years of age (97.6% of children were 6 or 7 years old) for the German city of Hannover. We propose the socio-economic status as a marker for different life-styles and social micro-environments in further studies as there were multiple significant correlations between individual social and environmental factors. The macro-environment seems to be less important for the disease outcome in this context.

Child↗

[Work-satisfaction and Health of Hospital Nursing and Medical Personnel].

The implementation of new service demands and increasing rationalisation measures exercise stress and pressure on medical and nursing personnel in German hospitals. However, their satisfaction and health are important quality criteria in the ranking of a hospital. Basing on the introduction of a new tool, an inquiry was conducted among the medical and nursing personnel of two hospitals (A and B) in respect of the quality of their working conditions. The scope of the questionnaires covered the nature and kind of the work, opportunities of professional success, management of co-operation and conflicts, physical and structural obstacles to smooth working as well as the management of quality. Finally, a scale of complaints and a burn-out scale served to assess the personnel's subjective health situation. The questionnaire was submitted in hospital A between November 1999 and February 2000 to a total of 39 doctors (58 % compliance) and 84 nursing personnel (47 % compliance) of the specialist departments concerned with internal medicine, rheumatology, urology, general and accident surgery. In hospital B the questionnaire was completed between March and July 2001 by a total of 40 doctors (54 %) and 91 nursing personnel (68 %) of two departments of internal medicine, surgery, neurosurgery and gynaecology. Comparable to other studies, the nursing personnel in both the hospitals rated the working conditions more negatively than the medical personnel. The differences, however, are more of a quantitative (number of frequency of problems) than of a qualitative nature (type or kind of problems). With both groups, problems connected with structural difficulties in working and with quality management were by far most important while the nursing personnel also underlined physical stress. Individual health condition were also classified more negatively by the nursing personnel than by the doctors, and the overall physical complaints of the nursing personnel were generally greater than with the average population, whereas medical personnel registered fewer complaints. Health promotion measures in hospitals may help to prevent negative developments. Such measures are too rarely translated into reality.

Germany↗

Self-release of ski-binding.

We investigated whether twenty-five male and female downhill skiers of different ages (11 - 63 years) and skiing skills were able to self-release their ski binding by an inward twist of the foot and leg. We also studied possible correlations between thigh muscle torques and the ability to release the binding. All subjects used the same ski and binding, Marker Titanum M48, individually set according to weight, height, skiing skill, age, and boot sole length. Prior to the test we used a special torque wrench, the Vermont Release Calibrator, to verify that the settings of the binding corresponded to the appropriate torque (Nm) to produce a release. Isokinetic concentric and eccentric quadriceps and hamstring torques were measured. EMG was used to study which muscles are engaged in this self-test. Nineteen skiers were able to release the binding, while four children and the two muscularly weakest skiers were not. The medial hamstrings produced the highest degree of muscle activity during the inward twist release of the binding. There was a highly significant correlation between thigh muscle torques and the ability to release the binding.

Adolescent↗

Retrieving biological activity from LukF-PV mutants combined with different S components implies compatibility between the stem domains of these staphylococcal bicomponent leucotoxins.

Bicomponent leucotoxins, such as Panton-Valentine leucocidin, are composed of two classes of proteins, a class S protein such as LukS-PV, which bears the cell membrane binding function, and a class F protein such as LukF-PV, which interacts to form a bipartite hexameric pore. These leucotoxins induce cell activation, linked to a Ca(2+) influx, and pore formation as two consecutive and independently inhibitable events. Knowledge of the LukF-PV monomer structure has indicated that the stem domain is folded into three antiparallel beta-strands in the water-soluble form and has to refold into a transmembrane beta-hairpin during pore formation. To investigate the requirements for the cooperative assembly of the stems of the S and F components to produce biological activity, we introduced multiple deletions or single point mutations into the stem domains of LukF-PV and HlgB. While the binding of the mutated proteins was weakly dependent on these changes, Ca(2+) influx and pore formation were affected differently, confirming that they are independent events. Ca(2+) entry into human polymorphonuclear cells requires oligomerization and may follow the formation of a prepore. The activity of some of the LukF-PV mutants, carrying the shorter deletions, was actually improved. This demonstrated that a crucial event in the action of these toxins is the transition of the prefolded stem into the extended beta-hairpins and that this step may be facilitated by small deletions that remove some of the interactions stabilizing the folded structure.

Amino Acid Sequence↗

The Mad1 transcription factor is a novel target of activin and TGF-beta action in keratinocytes: possible role of Mad1 in wound repair and psoriasis.

Activin A, a member of the transforming growth factor beta (TGF-beta) superfamily, affects keratinocyte proliferation and differentiation in vitro and in vivo. However, little is known about the mechanisms of activin action in keratinocytes, and its target genes have not been identified. In this study, we demonstrate that activin A and TGF-beta1 directly induce the expression and activity of Mad1, an antagonist of the c-Myc transcription factor, in the human HaCaT keratinocyte cell line. Expression and activity of Mad1 was strongly induced by both factors in keratinocytes, although the intensity of induction was different for activin A and TGF-beta1. To determine a possible role of activin and TGF-beta in the regulation of mad1 expression in vivo, we analysed its expression during cutaneous wound repair when high levels of these factors are present. Expression of mad1 mRNA and protein, but not of other mad genes, increased significantly after skin injury, particularly in polymorphonuclear leukocytes and in suprabasal keratinocytes of the hyperproliferative epithelium. Elevated levels of mad1 mRNA were also detected in the hyperthickened epidermis of psoriatic patients. Since Mad1 regulates proliferation and/or differentiation of various cell types, our results suggest that this transcription factor mediates at least in the part the anti-mitotic and/or differentiation-inducing activities of TGF-beta and activin in keratinocytes.

Activins↗

Impaired wound healing in transgenic mice overexpressing the activin antagonist follistatin in the epidermis.

Recently, we demonstrated a strong upregulation of activin expression after skin injury. Furthermore, overexpression of this transforming growth factor beta family member in the skin of transgenic mice caused dermal fibrosis, epidermal hyperthickening and enhanced wound repair. However, the role of endogenous activin in wound healing has not been determined. To address this question we overexpressed the soluble activin antagonist follistatin in the epidermis of transgenic mice. These animals were born with open eyes, and the adult mice had larger ears, longer tails and reduced body weight compared with non-transgenic littermates. Their skin was characterized by a mild dermal and epidermal atrophy. After injury, a severe delay in wound healing was observed. In particular, granulation tissue formation was significantly reduced, leading to a major reduction in wound breaking strength. The wounds, however, finally healed, and the resulting scar area was smaller than in control animals. These results implicate an important function of endogenous activin in the control of wound repair and scar formation.

Activins↗

The Ca2+-binding proteins S100A8 and S100A9 are encoded by novel injury-regulated genes.

To gain insight into the molecular mechanisms underlying cutaneous wound repair, we performed a large scale screen to identify novel injury-regulated genes. Here we show a strong up-regulation of the RNA and protein levels of the two Ca(2+)-binding proteins S100A8 and S100A9 in the hyperthickened epidermis of acute murine and human wounds and of human ulcers. Furthermore, both genes were expressed by inflammatory cells in the wound. The increased expression of S100A8 and S100A9 in wound keratinocytes is most likely related to the activated state of the keratinocytes and not secondary to the inflammation of the skin, since we also found up-regulation of S100A8 and S100A9 in the epidermis of activin-overexpressing mice, which develop a hyperproliferative and abnormally differentiated epidermis in the absence of inflammation. Furthermore, S100A8 and S100A9 expression was found to be associated with partially differentiated keratinocytes in vitro. Using confocal microscopy, both proteins were shown to be at least partially associated with the keratin cytoskeleton. In addition, cultured keratinocytes efficiently secreted the S100A8/A9 dimer. These results together with previously published data suggest that S100A8 and S100A9 are novel players in wound repair, where they might be involved in the reorganization of the keratin cytoskeleton in the wounded epidermis, in the chemoattraction of inflammatory cells, and/or in the defense against microorganisms.

Activins↗

The roles of activins in repair processes of the skin and the brain.

A recent study from our laboratory demonstrated a strong upregulation of activin expression during cutaneous wound healing. To further analyze the role of activin A in skin morphogenesis and wound repair, we generated transgenic mice that overexpress activin A under the control of the keratin 14 promoter. The latter targets expression of transgenes to the basal, proliferating layer of the epidermis. Hetero- as well as homozygous transgenic animals were viable and fertile. However, they were smaller than non-transgenic littermates and they had smaller ears and shorter tails. Histological analysis of their skin revealed dermal hyperthickening, mainly due to the replacement of fatty tissue by connective tissue, and an increase in suprabasal, partially differentiated epidermal layers. After cutaneous injury, a strong enhancement of granulation tissue formation was observed. Furthermore, the extent of re-epithelialization was increased in some of the wounds. These data demonstrate that activin A is a potent stimulator of the wound healing process. Using an in vivo model of local brain injury, we found that activin A also plays a significant role in the early cellular response to neuronal damage. Expression of activin mRNA and protein is markedly upregulated within a few hours of injury. If applied exogenously, recombinant activin A is capable of rescuing neurons from acute cell death. Studying the interaction between bFGF, a well-established neuroprotective agent, which is currently being tested in stroke patients, and activin A, we arrived at the unexpected conclusion that it is the strong induction of activin A by bFGF which endows the latter with its beneficial actions in patients. These findings suggest that the development of substances directly targeting activin expression or receptor binding should offer new possibilities in the acute treatment of stroke and brain trauma.

Activins↗

Haem oxygenase-1: a novel player in cutaneous wound repair and psoriasis?

Haem oxygenase (HO) is the rate-limiting enzyme in the degradation of haem. In addition to its obvious role in iron metabolism, a series of findings indicate an important role for HO in cellular protection against oxidative stress. This effect might be of particular importance during wound healing and also in inflammatory disease. Therefore we determined the expression of the two HO isoenzymes, HO-1 and HO-2, during the healing process of full-thickness excisional wounds in mice. We show a remarkable induction of HO-1 mRNA and protein expression within three days after skin injury. After completion of wound healing, HO-1 expression declined to basal levels. By contrast, expression of HO-2 was not significantly modulated by skin injury. In situ hybridization and immunohistochemistry revealed high HO-1 expression in inflammatory cells of the granulation tissue and in keratinocytes of the hyperproliferative epithelium. A strong overexpression of HO-1 was also observed in the skin of patients suffering from the inflammatory skin disease psoriasis. In addition, HO-2 mRNA levels were increased in the skin of psoriatic patients. Similar to wounded skin, inflammatory cells and keratinocytes of the hyperthickened epidermis were the major producers of HO-1 in psoriatic skin. In vitro studies with cultured keratinocytes revealed a potential role for reactive oxygen species (ROS), but not for growth factors and pro-inflammatory cytokines, as inducers of HO-1 expression in inflamed skin. Our findings suggest a novel role for HO in wound healing and inflammatory skin disease, where it might be involved in haem degradation and in the protection of cells from the toxic effects of ROS.

Adult↗

Circumscripted pigmentations after iron injections-treatment with Q-switched laser systems.

BACKGROUND AND OBJECTIVE: Cutaneous brown discolorations in the area of injection can be a cosmetically bothersome side effect from a parenteral iron treatment, and have not responded to an effective therapy until now. STUDY DESIGN/PATIENTS AND METHODS: We report retrospectively on five patients who were treated with the Q-switched ruby and/or Nd:YAG laser for circumscripted siderosis after intramuscular or intravenous iron injection. RESULTS: The number of required laser treatments was between 3 and 16. The clinical improvement after the first 2-4 sessions was the most impressive, especially after the application of the Nd:YAG laser. Hypopigmentation and scars did not develop. In one case hyperpigmentation appeared. CONCLUSIONS: This study shows that there is an effective method of clearing persistent brown discolorations with few side effects after parenteral iron therapy, using Q-switched laser technology.

Adult↗

[Benign melanosis of the lip. Treatment with the Q-switched ruby laser].

BACKGROUND AND OBJECTIVE: Benign melanosis of the lip represents a cosmetic problem for many of those who are afflicted. It responds well to therapy with Q-switched lasers. The value of previous studies has been limited by small numbers of cases or short follow-up times. PATIENTS/METHODS: In a retrospective study 9 patients were treated by the Q-switched ruby laser (694 nm, pulse duration 25-40 ns, spot size 4 mm, energy density 10 J/cm2) in the period from 5/94 to 10/99. The benignity of the lip melanosis was determined dermatoscopically. In one case, the diagnosis was also confirmed histologically by a punch biopsy. The follow-up time was between 6 months and 5 1/2 years. RESULTS: In 3 cases a complete clearance of the melanosis was achieved after one session, while in 6 patients a second treatment was required. There were no recurrences. Scars or pigment alterations were likewise not observed. CONCLUSIONS: The treatment of benign melanosis of the lip with the Q-switched ruby laser is an elegant and safe method with excellent cosmetic results.

Adult↗

Risk factors for leg injuries in female soccer players: a prospective investigation during one out-door season.

The following possible risk factors for leg injuries in female soccer players were studied: age, anatomical alignment, generalized joint laxity, thigh muscle torque, muscle flexibility, ligamentous laxity of the knee and ankle joints, recent injuries, and duration of soccer exposure. A total of 146 players from 13 teams in the second and third Swedish divisions underwent clinical examination, isokinetic measurements of quadriceps and hamstring torques, and testing of postural sway of the legs. All soccer-related leg injuries resulting in absence from at least one scheduled practice session or game were recorded during one outdoor season (April-October). In 50 players there were 61 traumatic injuries, and 17 players sustained 19 overuse injuries. The overall injury incidence rate (traumatic and overuse) was 5.49/1000 h of soccer. Variables significantly increasing the risk of traumatic leg injuries included generalized joint laxity, low postural sway of the legs, hyperextension of the knee joint, and a low hamstring-to-quadriceps ratio during concentric action. Multivariate logistic regression showed hyperextension of the knee joint, a low postural sway, reduced H/Q ratio during concentric action, and a higher exposure to soccer to significantly increase the risk of traumatic leg injury. All five players who suffered an anterior cruciate ligament injury during the study period had a lower hamstring-to-quadriceps ratio during concentric action on the injured side than on their noninjured side.

Adult↗