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Biomedical subjects

L Sävendahl

Publications and source records attributed to L Sävendahl.

17 recordsLinked to original sources
PubMed2006

Metacarpophalangeal pattern profile analysis: useful diagnostic tool for differentiating between dyschondrosteosis, Turner syndrome, and hypochondroplasia.

PURPOSE: To assess the value of the metacarpophalangeal pattern profile (MCPP) analysis as a diagnostic tool for differentiating between patients with dyschondrosteosis, Turner syndrome, and hypochondroplasia. MATERIAL AND METHODS: Radiographic and clinical data from 135 patients between 1 and 51 years of age were collected and analyzed. The study included 25 patients with hypochondroplasia (HCP), 39 with dyschondrosteosis (LWD), and 71 with Turner syndrome (TS). Hand pattern profiles were calculated and compared with those of 110 normal individuals. Pearson correlation coefficient (r) and multivariate discriminant analysis were used for pattern profile analysis. Pattern variability index, a measure of dysmorphogenesis, was calculated for LWD, TS, HCP, and normal controls. RESULTS: Our results demonstrate that patients with LWD, TS, or HCP have distinct pattern profiles that are significantly different from each other and from those of normal controls. Discriminant analysis yielded correct classification of normal versus abnormal individuals in 84% of cases. Classification of the patients into LWD, TS, and HCP groups was successful in 75%. The correct classification rate was higher (85%) when differentiating two pathological groups at a time. Pattern variability index was not helpful for differential diagnosis of LWD, TS, and HCP. CONCLUSION: Patients with LWD, TS, or HCP have distinct MCPPs and can be successfully differentiated from each other using advanced MCPP analysis. Discriminant analysis is to be preferred over Pearson correlation coefficient because it is a more sensitive and specific technique. MCPP analysis is a helpful tool for differentiating between syndromes with similar clinical and radiological abnormalities.

Adolescent↗
PubMed2006

Locally produced estrogen promotes fetal rat metatarsal bone growth; an effect mediated through increased chondrocyte proliferation and decreased apoptosis.

The importance of estrogens for the regulation of longitudinal bone growth is unequivocal. However, any local effect of estrogens in growth plate cartilage has been debated. Recently, several enzymes essential for estrogen synthesis were shown to be expressed in rat growth plate chondrocytes. Local production of 17beta-estradiol (E2) has also been demonstrated in rat costal chondrocytes. We aimed to determine the functional role of locally produced estrogen in growth plate cartilage. The human chondrocyte-like cell line HCS-2/8 was used to study estrogen effects on cell proliferation (3H-labeled thymidine uptake) and apoptosis (cell death detection ELISA kit). Chondrocyte production of E2 was measured by RIA and organ cultures of fetal rat metatarsal bones were used to study the effects of estrogen on longitudinal growth rate. We found that significant amounts of E2 were produced by HCS-2/8 chondrocytes (64.1 +/- 5.3 fmol/3 days/10(6) cells). The aromatase inhibitor letrozole (1 microM) and the pure estrogen receptor antagonist ICI 182,780 (10 microM) inhibited proliferation of HCS-2/8 chondrocytes by 20% (P < 0.01) and almost 50% (P < 0.001), respectively. Treatment with ICI 182,780 (10 microM) increased apoptosis by 228% (P < 0.05). Co-treatment with either caspase-3 or pan-caspase inhibitors completely blocked ICI 182,780-induced apoptosis (P < 0.001 vs ICI 182,780 only). Moreover, both ICI 182,780 (10 microM) and letrozole (1 microM) decreased longitudinal growth of fetal rat metatarsal bones after 7 days of culture (P < 0.01). In conclusion, our data clearly show that chondrocytes endogenously produce E2 and that locally produced estrogen stimulates chondrocyte proliferation and protects from spontaneous apoptosis. In addition, longitudinal growth is promoted by estrogens locally produced within the epiphyseal growth plate.

Animals↗
PubMed2005

Metacarpophalangeal pattern profile analysis as a tool for early diagnosis of Turner syndrome.

PURPOSE: To analyze the metacarpophalangeal pattern profile (MCPP) in a cohort of individuals with Turner syndrome (TS), and to assess its value as a tool for early diagnosis of TS. MATERIAL AND METHODS: Medical records and radiological material were collected of 71 patients with TS aged between 3 and 21 years. Forty-six patients received growth hormone therapy (33-66 microg kg(-1) day(-1)) and 14 of these were also treated with the anabolic steroid oxandrolone (1.25-3.75 mg day(-1)). A total of 233 frontal hand radiographs were studied and pattern profiles were calculated. Profiles of the TS patients were compared with those of 70 normal females. Mean pattern profiles were calculated for different age groups and extrapolated profiles for newborns and infants were developed. RESULTS: Our results confirm that patients with TS have a distinct MCPP which differs significantly from that of normal individuals. A bone-shortening gradient with increasing shortening from distal phalanges to metacarpals was demonstrated. We also showed that the MCPP in TS is a remarkably constant feature from 3 to 18 years. Pattern profiles did not differ significantly between the patients with 45,X and non-45,X karyotype. MCPP was not affected by treatment with growth hormone of growth hormone plus oxandrolone. Discriminant analysis yielded correct classification in 88%, of analyzed cases. CONCLUSION: TS individuals have a distinct hand pattern profile that is not age-related. MCPP analysis can be applied at any age and may facilitate early diagnosis of TS. Our study showed that MCPP analysis is a specific and sensitive method that should be considered as a routinely used tool for early diagnosis of TS in girls with unexplained short stature.

Adolescent↗
PubMed2004

Estrogen receptor-beta inhibits skeletal growth and has the capacity to mediate growth plate fusion in female mice.

UNLABELLED: To determine the long-term role of ER beta in the regulation of longitudinal bone growth, appendicular and axial skeletal growth was followed and compared in female ER beta-/-, ER alpha-/-, and ER alpha-/- beta-/- mice. Our results show that ER beta inhibits appendicular and axial skeletal growth and has the capacity to induce fusion of the growth plates. INTRODUCTION: Estrogen affects skeletal growth and promotes growth plate fusion in humans. In rodents, the growth plates do not fuse after sexual maturation, but prolonged treatment with supraphysiological levels of estradiol has the capacity to fuse the growth plates. It should be emphasized that the estrogen receptor (ER) alpha-/- and the ER alpha-/- beta-/-, but not the ER beta-/-, mouse models have clearly increased serum levels of estradiol. MATERIALS AND METHODS: The skeletal growth was monitored by X-ray and dynamic histomorphometry, and the growth plates were analyzed by quantitative histology, calcein double labeling, bromodeoxyuridine (BrdU) incorporation, and TUNEL assay in 4- and 18-month-old female ER beta-/-, ER alpha-/-, and ER alpha-/- beta-/- mice. RESULTS: Young adult (4-month-old) ER beta-/- mice demonstrated an increased axial- and appendicular-skeletal growth, supporting the notion that ER beta inhibits skeletal growth in young adult female mice. Interestingly, the growth plates were consistently fused in the appendicular skeleton of 18-month-old female ER alpha-/- mice. This fusion of growth plates, caused by a prolonged exposure to supraphysiological levels of estradiol in female ER alpha-/- mice, must be mediated through ER beta because old ER alpah-/- beta-/- mice displayed unchanged, unfused growth plates. CONCLUSIONS: Our results confirm that ER beta is a physiological inhibitor of appendicular- and axial-skeletal growth in young adult female mice. Furthermore, we made the novel observation that ER beta, after prolonged supraphysiological estradiol exposure, has the capacity to mediate growth plate fusion in old female mice.

Absorptiometry, Photon↗
PubMed2003

Growth retardation induced by dexamethasone is associated with increased apoptosis of the growth plate chondrocytes.

Glucocorticoids cause significant growth retardation in mammals and humans and decreased proliferation of chondrocytes has been considered as the main local mechanism. Death by apoptosis is an important regulator of homeostasis in multicellular organisms. Here we chose to study the role of apoptosis in growth retardation caused by glucocorticoid treatment. We treated 7-week-old male rats with dexamethasone (5 mg/kg/day) for 7 days. Apoptosis was studied in tibiae growth plates by the TUNEL method. Immunoreactivity for parathyroid hormone-related peptide (PTHrP), caspase-3, and the anti-apoptotic proteins Bcl-2 and Bcl-x was also studied. Apoptosis was mainly localized in terminal hypertropic chondrocytes (THCs) in both control and dexamethasone-treated animals. Dexamethasone caused an increase in apoptosis which was fourfold in THCs (2.45+/-0.12 vs 0.62+/-0.09 apoptotic cells/mm growth plate, P<0.001), and 18-fold in proliferative chondrocytes (0.18+/-0.04 vs 0.01+/-0.007 apoptotic cells/mm growth plate, P<0.001). Increased apoptosis after dexamethasone treatment was accompanied by increased immunoreactivity for caspase-3 and decreased immunoreactivity for the anti-apoptotic proteins Bcl-2 and Bcl-x, which further supports our apoptosis results. Dexamethasone also decreased the immunoreactivity for PTHrP, suggesting a role in the mechanism by which glucocorticoids induce apoptosis in the growth plate. We conclude that apoptosis is one mechanism involved in growth retardation induced by glucocorticoids. Premature loss of resting/proliferative chondrocytes by apoptosis could contribute to incomplete catch-up seen after prolonged glucocorticoid treatment.

Animals↗
PubMed2002

Estrogen receptor-alpha and -beta are expressed throughout postnatal development in the rat and rabbit growth plate.

Estrogen regulates skeletal growth and promotes epiphyseal fusion. To explore the mechanisms underlying these effects we investigated the expression of estrogen receptor-alpha (ERalpha) and -beta (ERbeta) in rat and rabbit growth plates during postnatal development, using immunohistochemistry. Immunoreactivity for ERalpha and ERbeta was observed in resting zone and proliferative zone chondrocytes at all ages studied for both rat (7, 14, 28 and 70 days of age) and rabbit (1, 7, 28 and 120 days of age). In the rat distal humerus and the rabbit proximal tibia, expression of both receptors in the hypertrophic zone was minimal at early ages, increasing only at the last time point prior to epiphyseal fusion. Expression was rarely seen in the hypertrophic zone of the rat proximal tibia, a growth plate that does not fuse until late in life. Therefore, we conclude that ERalpha and ERbeta are both expressed in the mammalian growth plate. The temporal and anatomical pattern suggests that ER expression in the hypertrophic zone in particular may play a role in epiphyseal fusion.

Aging↗
PubMed2002

Expression and localization of Indian hedgehog (Ihh) and parathyroid hormone related protein (PTHrP) in the human growth plate during pubertal development.

Indian Hedgehog (Ihh) has been reported to control the rate of cartilage differentiation during skeletal morphogenesis in rodents through a negative feedback loop involving parathyroid hormone related protein (PTHrP). The role of Ihh and PTHrP in the regulation of human epiphyseal chondrocytes is unknown. The aim of the current study was to examine the expression and localization of Ihh and PTHrP in the human growth plate at various pubertal stages. Growth plate biopsies were obtained from patients subjected to epiphyseal surgery and the expression of Ihh and PTHrP was detected by immunohistochemistry. We show that Ihh and PTHrP are expressed mainly in early hypertrophic chondrocytes in the human growth plate. The levels of expression of Ihh and PTHrP are higher in early stages of puberty than later. Our results suggest that Ihh and PTHrP are present in the human growth plate and that Ihh and PTHrP may be involved in the regulation of pubertal growth in humans.

Adolescent↗
PubMed2000

Delayed diagnoses of Turner's syndrome: proposed guidelines for change.

OBJECTIVE: To measure the delays in diagnosis of Turner's syndrome (TS) and to propose strategies for earlier screening and diagnosis. METHODS: The medical records of 81 girls with TS were reviewed for age at diagnosis, reason(s) for karyotype analysis, and clinical features including growth failure. Delay in diagnosis was calculated as equal to age at diagnosis for children born with lymphedema and/or 2 or more of the following dysmorphic features: webbed neck, nail dysplasia, high palate, and short fourth metacarpal. For all others, delay in diagnosis was calculated as the difference between the age at which height fell below the 5th percentile and the age at which the diagnosis of TS was made. RESULTS: Lymphedema was the key to diagnosis in 97% of the girls diagnosed with TS in infancy, and short stature was the key to diagnosis for 82% of the girls diagnosed in childhood or adolescence. For girls diagnosed in childhood or adolescence, the delay in diagnosis averaged 7.7 +/- 5.4 years. Many had dysmorphic features and/or a history of lymphedema at birth, and diagnosis was made an average of 5.3 years after patients had fallen below the 5th percentile for height. By the time of diagnosis, patients were very short, averaging -2.9 SD in height. CONCLUSIONS: The diagnosis of TS is often delayed. We recommend karyotype analysis for all girls with unexplained short stature, delayed puberty, webbed neck, lymphedema, or coarctation of the aorta. Furthermore, karyotype analysis should be strongly considered for those who remain above the 5th percentile for height but have 2 or more features of TS, including high palate, nail dysplasia, short fourth metacarpal, and strabismus.

Adolescent↗
PubMed1999

Disproportional body growth in female estrogen receptor-alpha-inactivated mice.

Estrogens play an important role in the regulation of longitudinal bone growth in man, as demonstrated by recent descriptions of individuals with estrogen insensitivity or aromatase deficiency. Two estrogen receptors, ERalpha and ERbeta, have been cloned. The aim of the present study was to investigate the function of ERalpha in the regulation of body growth and skeletal growth. Adult female mice with inactivated ERalpha (ERalpha-/-) demonstrated an increased body weight compared with wild-type mice (114% of control). However, the length of the appendicular skeleton was decreased in adult ERalpha-/- mice (femur 93% of control). In contrast, the axial skeleton was normal (crown-rump length 98% of control). The decreased growth of the appendicular skeleton was associated with decreased serum levels of IGF-I (77% of control), indicating that the GH/IGF-I axis may be involved in the decreased longitudinal bone growth seen in female ERalpha-/- mice.

Animals↗
PubMed1999

Fasting increases serum total cholesterol, LDL cholesterol and apolipoprotein B in healthy, nonobese humans.

Voluntary fasting is practiced by many humans in an attempt to lose body weight. Conflicting results have been published on the effects of food deprivation on serum lipids. To study the effect of acute starvation on serum lipids, 10 nonobese (93-124% of ideal body weight), healthy adults (6 men, 4 women, 21-38 y old) fasted (no energy) for 7 d. Fasting increased total serum cholesterol from 4.90 +/- 0.23 to 6.73 +/- 0.41 mmol/L (37.3 +/- 5.0%; P < 0.0001) and LDL cholesterol from 2.95 +/- 0.21 to 4.90 +/- 0.36 mmol/L (66.1 +/- 6. 6%; P < 0.0001). Serum apolipoprotein B (apo B) increased from 0.84 +/- 0.06 to 1.37 +/- 0.11 g/L (65.0 +/- 9.2%; P < 0.0001). The increases in serum cholesterol, LDL and apo B were associated with weight loss. Fasting did not affect serum concentrations of triacylglycerol and HDL cholesterol. Serum concentrations of insulin-like growth factor-I (IGF-I) decreased from 246 +/- 29 (prefast) to 87 +/- 10 microg/L after 1 wk of fasting (P < 0.0001). We conclude that, in nonobese subjects, fasting is accompanied by increases in serum cholesterol, LDL and apo B concentrations, whereas IGF-I levels are decreased.

Adult↗
PubMed1999

Demonstration of estrogen receptor-beta immunoreactivity in human growth plate cartilage.

Estrogens affect longitudinal bone growth through their action on endochondral bone formation. Two estrogen receptors are known, the classical estrogen receptor-alpha (ER alpha), newly demonstrated in human growth plate cartilage, and a recently cloned estrogen receptor-beta (ER beta). The present study aimed to localize a possible expression of ER beta protein in human growth plates. Tissue samples were obtained from tibial and femoral growth plates in four female pubertal patients undergoing epiphyseal surgery. Immunohistochemistry, using two different ER beta-specific antibodies, demonstrated positive staining for ER beta in hypertrophic epiphyseal chondrocytes from all patients. No staining was noted in resting or proliferative chondrocytes. These data suggest that in addition to ER alpha, human epiphyseal chondrocytes also express ER beta. The physiological role of ER beta in the regulation of longitudinal bone growth in humans remains to be elucidated.

Adolescent↗
PubMed1997

Fasting prevents experimental murine colitis produced by dextran sulfate sodium and decreases interleukin-1 beta and insulin-like growth factor I messenger ribonucleic acid.

Cytokines and insulin-like growth factors (IGFs) are involved in the induction and/or perpetuation of inflammatory bowel disease. The effect of fasting on inflammatory bowel disease was studied in a mouse experimental model of acute colitis caused by adding dextran sulfate sodium (DSS) to drinking water. Animals were either fed ad libitum or fasted (water only) for 2 days before death. Inflammation and tissue damage, measured as a colitis activity score, were markedly reduced in fasted (2.4 +/- 0.1) compared to fed (5.3 +/- 0.1) DSS animals (P < 0.0001). Colon interleukin-1 beta (IL-1 beta), IGF-I, and tumor necrosis factor-alpha messenger RNAs (mRNAs) were quantified by Northern blot hybridization and expressed as a percentage of mRNA abundance in fed controls. In DSS mice, IL-1 beta mRNA was elevated in the fed group (954 +/- 155%; P < 0.001), but was suppressed in fasted animals (71.1 +/- 11%). IGF-I mRNA also was elevated in fed DSS mice (421 +/- 71%; P < 0.01). This increase was attenuated in fasted DSS mice (202 +/- 17%; P < 0.01 compared to fed DSS mice). Tumor necrosis factor-alpha mRNA was increased in fed DSS mice (162 +/- 15%; P < 0.01), but was not significantly lower in fasted animals. By in situ hybridization, IL-1 beta mRNA was localized to the lamina propria of colonic mucosa in fed DSS animals, but was not detectable in other groups. We conclude that fasting has a protective effect on the progression of acute DSS, induced colitis. This is associated with decreased expression of IL-1 beta and IGF-I mRNAs in the colon.

Animals↗
PubMed1997

Decreased interleukin-2 production from cultured peripheral blood mononuclear cells in human acute starvation.

Depressed cell-mediated immunity and decreased insulin-like growth factor I (IGF-I) are observed in malnourished humans. To study the interaction among nutrition, IGF-I, and cytokines, healthy volunteers (six men and four women, aged 21-38 yr, weighing 93-124% of ideal body weight) were subjected to a 7-day fast (mineral water only). Fasting steadily decreased serum IGF-I from 247 +/- 29 (prefast) to 87 +/- 10 ng/mL (postfast; P < 0.0001), total T cells (CD3+) from 1499 +/- 68 to 1308 +/- 70 x 10(9) (P < 0.0001), and T helper cells (CD4+) from 997 +/- 62 to 856 +/- 55 x 10(9) (P < 0.001). Peripheral blood mononuclear cells were isolated and cultured in serum-free RPMI 1640 for 24 h. Fasting attenuated peripheral blood mononuclear cell production of interleukin-2 in response to various concentrations of phytohemagglutinin P [PHA-P; 347 +/- 48 (prefast) vs. 135 +/- 52 pg/mL (postfast) when challenged with 3 micrograms/mL PHA-P; P < 0.005 when comparing dose-response curves (1-100 micrograms/mL PHA-P)]. Although the approximately 3-fold suppression of interleukin-2 and IGF-I in subjects fasted for 1 week is not likely to affect immune function significantly, our results with this short term model of nutrient restriction provide insight into possible mechanisms for immune suppression in chronic starvation.

Acute Disease↗
PubMed1995

Cell volume and shape oscillations in rat type-II somatotrophs at hypotonic conditions.

The size and shape of growth hormone (GH)-producing rat type-II somatotrophs was studied during osmotic manipulation. When somatotrophs were exposed to large osmotic stress (200 and 225 mOsm), the peak projected cell area (PCA) was 132.9% +/- 12.6% and 116.8% +/- 2.8% (P < 0.01) and triggered a regulatory volume decrease (RVD) to avoid lysis. At lower osmotic stress (250 mOsm), the rate of swelling was slower, and the volume reached a steady state at 109.4% +/- 2.4% (P < 0.05) and was without RVD. At 275 and 287 mOsm, the swelling was delayed [PCA peak at 3-4 min; 105.8% +/- 1.5% (P < 0.05) and 104.2% +/- 1.7%] and then showed repeated synchronized cycles of swelling and shrink-age (P < 0.05). The data suggest that somatotrophs may have more than one mechanism for volume regulation. One mechanism is for large swelling (classic RVD response), whereas the other represents more physiological mechanisms for regulating the cell volume within a more limited geometry range. For low osmotic stress (250-287 mOsm), the somatotrophs became less spherical during swelling and, thus, were without membrane dilation. Therefore, this type of volume regulation must work independently from membrane stress. Related volume regulation mechanisms may underlie the previously observed volume fluctuations in somatotrophs seen during secretory stimulation with GH-releasing hormone.

Animals↗
PubMed1994

Lack of evidence for acute effects of growth hormone-releasing hormone on serum insulin and glucose levels in normal and hypophysectomized rats.

Growth hormone (GH) is diabetogenic but has also been suggested to stimulate insulin release. Our aim was to study whether acute effects of GH on serum insulin and glucose concentrations can be observed when GH release is physiologically induced by GH-releasing hormone (GHRH), which is known to stimulate insulin secretion. We also studied the acute effects of GHRH as such on insulin release in vivo and in vitro. Female Sprague-Dawley rats were hypophysectomized (hypox) at 40 days of age. At day 188, rats received 1 microgram GHRH(1-29)/100 g body weight i.v. In sham-operated rats, GHRH induced a rise in serum GH from 36.5 +/- 1.9 ng/ml (time 0 min) to 560.0 +/- 13.3 ng/ml (5 min;) (n = 6; p < 0.001). In hypox rats, no measurable serum levels of GH were detected either before or after GHRH treatment. Serum insulin was unaffected by GHRH in both groups of animals. Serum glucose was higher in sham operated than in hypox rats (7.3 +/- 0.4 vs. 6.3 +/- 0.1 mM at 0 min; p < 0.01). Serum glucose did not rise following GHRH injection. In isolated rat islets, cultured for 3 days at 11.1 mM glucose, 0.1-10 nM GHRH stimulated basal insulin release at 3 mM glucose. To summarize, GHRH at high concentrations stimulates insulin release in vitro, but neither GHRH, at a concentration where GH secretion is greatly stimulated, nor GHRH-induced GH release, have any acute effects on serum insulin or glucose levels.

Animals↗
PubMed1993

Effects of galanin on growth hormone release in isolated cultured rat somatotrophs.

Several studies suggest that galanin stimulates growth hormone release through effects on the hypothalamus. It is not known if galanin has acute effects directly on the somatotrophs. We now find that 0.5 mumol/l galanin stimulates growth hormone release within the first minute of exposure in isolated, purified, cultured male rat somatotrophs. The effect persisted for 15 min and was reversible when galanin was omitted. Galanin reduced the effect of 1 nmol/l growth hormone-releasing hormone (hGHRH(1-29)) on growth hormone release. Galanin stimulated 45Ca efflux from prelabelled cells but had no effect on 86Rb efflux (tracer for potassium). The findings support the fact that galanin can stimulate growth hormone release directly at the level of the somatotrophs. The cellular mechanisms for the effect of galanin probably differ from those of growth hormone-releasing hormone.

Animals↗