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Lynnette K Nieman

Publications and source records attributed to Lynnette K Nieman.

At least 19 recordsLinked to original sources
PubMed2007

Effects of child- and adolescent-onset endogenous Cushing syndrome on bone mass, body composition, and growth: a 7-year prospective study into young adulthood.

UNLABELLED: The long-term effects on bone and fat mass in children with endogenous CS are unknown. In 14 children followed for 3-7 years into young adulthood after cure of CS, whereas bone mass largely recovered, persisting increases in total body and visceral fat suggests an increase risk of the metabolic syndrome. INTRODUCTION: Endogenous Cushing syndrome (CS) is associated with decreased bone mass and increased central fat mass. Whereas bone mass seems to improve after successful treatment, little is known about whether central fat persists. MATERIALS AND METHODS: This was a prospective study of 14 children (10 girls and 4 boys) and adolescents with CS who were successfully treated and remained eucortisolemic. Growth, puberty, bone mass, and body composition were evaluated at baseline and during regular follow-up for 3 years and in seven children for a further 4 years of remission to assess final adult height (FH), BMI, bone mass, and body composition. RESULTS: CS compromised growth, leading to about a -0.8 SD loss of FH and 0.9 SD increase in weight and BMI. BMD apparent density (BMAD) SD Score (SDS) at the lumbar spine (LS) at diagnosis were -1.8 and -1.25, respectively, and after 3 years of follow-up approached the mean with no further increase apparent up to 7 years of follow-up. Whereas hip BMD SDS increased from -1.3 at diagnosis to -0.40 at 3 years and 0 at 7 years of follow-up, femoral neck BMAD remained at or around 0 SDS at diagnosis and during follow-up. BMI was >25 kg/m(2) in five of seven adult subjects, most of whom were women. Total body fat and the ratio of visceral to subcutaneous was abnormally high in the majority of these subjects, whereas LS volumetric BMD was -0.7 SDS. CONCLUSIONS: Despite remission of CS, children and adolescents have significant alterations in body composition that result in a small but significant decrease in bone mass and increase in visceral adiposity. Although bone mass largely recovers after endogenous CS, changes in total and visceral fat suggest these subjects are at increased risk of the metabolic syndrome. Therefore, long-term monitoring of body fat and bone mass is mandatory after treatment of CS.

Adolescent↗
PubMed2006

Persistence of dysmenorrhea and nonmenstrual pain after optimal endometriosis surgery may indicate adenomyosis.

OBJECTIVE: To evaluate whether persistence of pelvic pain after excision of endometriosis was associated with adenomyosis as defined by a thickened uterine junctional zone (JZ) on magnetic resonance (MR) imaging. DESIGN: Prospective clinical trial. SETTING: Government research hospital. PATIENT(S): Fifty-three women with chronic pelvic pain. INTERVENTION(S): Preoperative MR imaging to measure uterine JZ thickness, surgical excision, and pathologic diagnosis of endometriosis. Those with biopsy-proven endometriosis were randomized to raloxifene or placebo. Visual analog scale (VAS) was used to rate dysmenorrhea and nonmenstrual pain severity before surgery and 3 months later. MAIN OUTCOME MEASURE(S): Comparison of JZ thickness and pain severity before and 3 months after surgery in women with endometriosis controlling for medical treatment. RESULT(S): Forty of the 53 patients had biopsy-proven endometriosis, and 6 of these 40 women with endometriosis had a thickened JZ. Overall, dysmenorrhea at 3 months was positively correlated with preoperative JZ thickness (r = 0.47, P=.01). Dysmenorrhea pain severity showed no significant decrease in those patients whose JZ measured >or=11 mm compared with those with JZ <8 mm (P<.0001; VAS decreased 4.3 +/- 0.6), or >or=8 and <11 mm (P<.02; VAS decreased 4.8 +/- 1.3). Nonmenstrual pain severity was correlated with JZ thickness (r = 0.51, P=.004) at 3 months with a significant decrease in nonmenstrual pain only in women with a JZ <8 mm (VAS decreased 4.0 +/- 0.7, P<.0001). The association between dysmenorrhea and nonmenstrual pain reduction and thinner JZ remained after controlling for medical treatment. CONCLUSION(S): Following surgical excision of endometriosis, chronic pelvic pain was significantly more likely to persist with JZ thickness >11mm on preoperative MR imaging. This suggests that myometrial JZ abnormalities or adenomyosis may contribute to chronic pelvic pain in women with endometriosis.

Adult↗
PubMed2006

Cushing's syndrome.

Cushing's syndrome results from lengthy and inappropriate exposure to excessive glucocorticoids. Untreated, it has significant morbidity and mortality. The syndrome remains a challenge to diagnose and manage. Here, we review the current understanding of pathogenesis, clinical features, diagnostic, and differential diagnostic approaches. We provide diagnostic algorithms and recommendations for management.

Adrenocorticotropic Hormone↗
PubMed2006

Surgical remission of pituitary adenomas confined to the neurohypophysis in Cushing's disease.

CONTEXT: Partial or total removal of the pituitary cures 60-80% of patients with Cushing's disease (CD) in whom an adenoma cannot be identified at surgery. Many patients who fail complete or partial hypophysectomy are cured by sellar and parasellar irradiation. DESIGN/PATIENTS: As part of a series of prospective studies of CD, we identified 12 patients (34.5 +/- 19.9 yr; 11 females; four children) with tumors located completely within the neurohypophysis among 730 patients undergoing surgery for CD. SETTING: The study was conducted at a tertiary referral center at a clinical research hospital. RESULTS: All 12 patients had clinical and biochemically defined CD. Tumor was visible at surgery in 11 patients; all 12 tumors were positive for ACTH by immunohistochemistry. Two tumors were excised at repeat surgery because of persistent hypercortisolism within 14 d of negative exploration of the adenohypophysis. There were no long-term complications. At follow-up of 71.9 +/- 34.2 months (range, 30-138 months), all patients are in remission of CD. Adult patients have had significant improvement in weight and body mass indices, with restoration of normal menses in all women. In the four pediatric patients, height, weight, and body mass indices have been restored toward normal by surgical remission of CD. Hypopituitarism or long-term neurohypophysial dysfunction has not occurred. CONCLUSION: We report a new subset of patients with CD, ACTH-secreting adenomas that arise wholly within the posterior lobe of the pituitary gland. In cases of CD in which an adenoma is not identified in the adenohypophysis and in patients with persistent hypercortisolism after complete or partial excision of the anterior lobe, tumor within the neurohypophysis should be considered; selective adenomectomy of a neurohypophyseal, ACTH-secreting tumor can produce long-term remission.

Adenoma↗
PubMed2006

Difficulty in the diagnosis of Cushing disease.

BACKGROUND: A 48-year-old woman presented to our clinic 1 year after hypertension was discovered on a routine screening visit. During the previous year, she had noticed weight gain in the face and abdomen, easy bruising, oligomenorrhea and facial and periareolar hair growth. On presentation, she reported no weakness, fracture, back pain, depression, irritability, problem with cognition or memory, increased appetite, hot flashes or altered sleep. Previous medication history included 2.5 mg lisinopril daily and 25.0 mg hydrochlorothiazide daily for 12 months. INVESTIGATIONS: Measurement of urine glucocorticoid excretion, evening plasma and salivary cortisol levels, and basal and corticotropin-releasing-hormone-stimulated adrenocorticotropic hormone and cortisol levels. An overnight 8 mg dexamethasone suppression test, pituitary MRI, inferior-petrosal-sinus sampling, cavernous sinus and jugular venous sampling were performed. DIAGNOSIS: Cushing disease. MANAGEMENT: The patient underwent trans-sphenoidal resection, assessment of remission and subsequent treatment with hydrocortisone.

17-Hydroxycorticosteroids↗
PubMed2005

Long-term impaired quality of life in Cushing's syndrome despite initial improvement after surgical remission.

CONTEXT: Cushing's syndrome (CS) is associated with symptoms that may impair health-related quality of life (HRQL). METHODS: We used the short-form 36 survey to evaluate HRQL in 23 patients with Cushing's disease before and after transsphenoidal surgery (age, 42.7 +/- 12.0 yr; 19 women and four men) and in a cross-section of 343 CS patients (age, 48.2 +/- 14.1 yr; 265 women and 78 men) in remission for up to 25.8 yr after surgery (adrenal, 5%; ectopic, 6%). The z-scores were calculated for short-form 36 domains, and physical (PCS) and mental (MCS) summary scores were compared with those of age- and sex-matched controls (n = 6742). RESULTS: Active Cushing's disease was associated with low PCS and MCS scores (P < 0.05). Despite residual postoperative impairment, primarily of physical domains, all HRQL parameters improved after treatment with transsphenoidal surgery (3.2 +/- 1.5 yr; P < 0.05). In the cross-section in remission at follow-up, there was a small, but significant (P < 0.05), impairment of both PCS and MCS. A longitudinal postoperative analysis confirmed stable, but impaired, HRQL over time. Logistic regression demonstrated that previous pituitary radiation and current glucocorticoid use had little effect on HRQL outcomes. CONCLUSION: CS is associated with impaired HRQL, which partially resolves after treatment. At longer-term follow-up, however, there is residual impairment of HRQL. Determination of modifiable factors that contribute to impaired HRQL may help reduce the physical and psychosocial burden of this disease.

Adolescent↗
PubMed2005

Cushing's syndrome due to ectopic corticotropin secretion: twenty years' experience at the National Institutes of Health.

CONTEXT: Ectopic ACTH secretion (EAS) is difficult to diagnose and treat. We present our experience with EAS from 1983 to 2004. SETTING: The study was performed at a tertiary care clinical research center. PATIENTS: Ninety patients, aged 8-72 yr, including 48 females were included in the study. INTERVENTIONS AND OUTCOME MEASURES: Tests included 8 mg dexamethasone suppression, CRH stimulation, inferior petrosal sinus sampling (IPSS), computed tomography, octreotide scan, magnetic resonance imaging, and/or venous sampling. Therapies, pathological examinations, and survival were noted. RESULTS: Eighty-six to 94% of patients did not respond to CRH or dexamethasone suppression, whereas 66 of 67 had negative IPSS. To control hypercortisolism, 62 patients received medical treatment, and 33 had bilateral adrenalectomy. Imaging localized tumors in 67 of 90 patients. Surgery confirmed an ACTH-secreting tumor in 59 of 66 patients and cured 65%. Nonthymic carcinoids took longest to localize. Deaths included three of 35 with pulmonary carcinoid, two of five with thymic carcinoid, four of six with gastrinoma, two of 13 with neuroendocrine tumor, two of two with medullary thyroid cancer, one of five with pheochromocytoma, three of three with small-cell lung cancer, and two of 17 with occult tumor. Patients with other carcinoids and ethesioneuroblastoma are alive. CONCLUSIONS: IPSS best identifies EAS. Initial failed localization is common and suggests pulmonary carcinoid. Although only 47% achieved cure, survival is good except in patients with small-cell lung cancer, medullary thyroid cancer, and gastrinoma.

Adolescent↗
PubMed2005

Sex-related differences in stimulated hypothalamic-pituitary-adrenal axis during induced gonadal suppression.

CONTEXT: Sex-related differences in the stress response are well described in the animal literature but in humans are inconsistent and appear to reflect both the method used to stimulate the hypothalamic-pituitary-adrenal (HPA) axis and the age of the subjects. Sex-related differences in reproductive steroid levels further confound efforts to define the specific role of the sex of the individual in stress axis responsivity. OBJECTIVE: The aim of this study was to address this role independent of differences in reproductive steroid levels. We compared HPA axis response to pharmacological (CRH) and physiological (exercise) stressors in two groups of young to middle-aged (18-45 yr) men (n = 10 and 8) and women (n = 12 and 13) undergoing gonadal suppression with leuprolide acetate (monthly im injection of 7.5 mg in men and 3.75 mg in women). DESIGN: Exercise and CRH stimulation tests were performed during induced hypogonadal conditions. SETTING: The study was conducted at a National Institutes of Health Clinical Center Outpatient Clinic. PATIENT OR OTHER PARTICIPANTS: Male and female normal volunteers participated in the study. MAIN OUTCOME MEASURES: The main outcome measures were stimulated ACTH and cortisol levels. RESULTS: Both CRH (1 microg/kg) stimulation and graded treadmill exercise stimulation occurred in the month after the second leuprolide injection to ensure gonadal suppression. Despite the absence of sex differences in estradiol or testosterone at the time of testing, men showed increased stimulated ACTH (repeated-measures ANOVA for CRH, P < 0.005) and cortisol (repeated-measures ANOVA for exercise, P < 0.05) compared with women. Among the summary measures, area under the curve (AUC) for cortisol was significantly greater in men than women after exercise. Although the AUC for ACTH was not significantly different across sexes, the initial AUC (0-30 min) was significantly greater in men for both procedures. No significant sex differences were found in a measure of adrenal responsivity, the cortisol to ACTH ratio, for either procedure. Cortisol-binding globulin levels did not differ between men and women and were not correlated with stimulated HPA axis measures. These data confirm earlier reports of sex differences in stimulated HPA axis activity and demonstrate that these differences exist even under induced hypogonadal conditions (i.e. in the absence of characteristic differences in reproductive steroids).

Adolescent↗
PubMed2005

The hypothalamic-pituitary-adrenal axis in pregnancy: challenges in disease detection and treatment.

Pregnancy dramatically affects the hypothalamic-pituitary-adrenal axis leading to increased circulating cortisol and ACTH levels during gestation, reaching values in the range seen in Cushing's syndrome (CS). The cause(s) of increased ACTH may include placental synthesis and release of biologically active CRH and ACTH, pituitary desensitization to cortisol feedback, or enhanced pituitary responses to corticotropin-releasing factors. In this context, challenges in diagnosis and management of disorders of the hypothalamic-pituitary-adrenal axis in pregnancy are discussed. CS in pregnancy is uncommon and is associated with fetal morbidity and mortality. The diagnosis may be missed because of overlapping clinical and biochemical features in pregnancy. The proportion of patients with primary adrenal causes of CS is increased in pregnancy. CRH stimulation testing and inferior petrosal sinus sampling can identify patients with Cushing's disease. Surgery is a safe option for treatment in the second trimester; otherwise medical therapy may be used. Women with known adrenal insufficiency that is appropriately treated can expect to have uneventful pregnancies. Whereas a fetal/placental source of cortisol may mitigate crisis during gestation, unrecognized adrenal insufficiency may lead to maternal or fetal demise either during gestation or in the puerperium. Appropriate treatment and management of labor are reviewed.

Adrenal Gland Diseases↗
PubMed2005

Cushing's syndrome during pregnancy: personal experience and review of the literature.

Cushing's syndrome (CS) occurs rarely during pregnancy. We investigated and treated four patients with pituitary-dependent Cushing's syndrome during pregnancy over a 15-yr period at the National Institutes of Health. Except for preservation of menses before conception, our patients presented with typical clinical features, increased urinary free cortisol, and loss of diurnal variation of cortisol. The diagnosis was facilitated, without complications, by the use of CRH testing and inferior petrosal sinus sampling in three women. Transsphenoidal pituitary surgery achieved remission in three women, but there were two fetal/neonatal deaths. This experience and review of 136 previous reports suggest that: 1) urinary free cortisol in CS patients overlaps the normal pregnant range; 2) ACTH levels are not suppressed in adrenal causes of CS, which may be identified by the 8-mg dexamethasone test; 3) inferior petrosal sinus sampling and transsphenoidal pituitary surgery, the optimal diagnostic test and treatment for nonpregnant patients with pituitary-dependent Cushing's syndrome, can safely facilitate the management of pregnant patients; and 4) surgery may achieve remission during pregnancy, but the prognosis for the fetus remains guarded. It is likely that earlier recognition and treatment would improve outcome. There is a need for development of criteria for interpretation of diagnostic tests and increased consideration of CS in pregnancy.

Adrenocorticotropic Hormone↗
PubMed2005

Evaluation and treatment of Cushing's syndrome.

Cushing's syndrome results from sustained pathologic hypercortisolism caused by excessive corticotropin (ACTH) secretion by tumors in the pituitary gland (Cushing's disease, 70%) or elsewhere (15%), or by ACTH-independent cortisol secretion from adrenal tumors (15%). The clinical features are variable, and no single pattern is seen in all patients. Those features most specific for Cushing's syndrome include abnormal fat distribution, particularly in the supraclavicular and temporal fossae, proximal muscle weakness, wide purple striae, and decreased linear growth with continued weight gain in a child. Patients with characteristics of glucocorticoid excess should be screened with measurements of saliva or urine cortisol or dexamethasone suppression testing. The diagnosis of Cushing's syndrome should be followed by the measurement of plasma ACTH concentration to determine whether the hypercortisolism is ACTH-independent. In ACTH-dependent patients, bilateral inferior petrosal sinus sampling with measurement of ACTH before and after administration of ACTH-releasing hormone most accurately distinguishes pituitary from ectopic ACTH secretion. Surgical resection of tumor is the optimal treatment for all forms of Cushing's syndrome; bilateral adrenalectomy, medical treatment, or radiotherapy are sought in inoperable or recurrent cases. The medical treatment of choice is ketoconazole. The prognosis is better for Cushing's disease and benign adrenal causes of Cushing's syndrome than adrenocortical cancer and malignant ACTH-producing tumors.

Adrenalectomy↗
PubMed2005

Differential diagnosis and imaging in Cushing's syndrome.

Establishing the cause of Cushing's syndrome (CS) is one of the most challenging processes in clinical endocrinology. Biochemical testing, including measurement of plasma adrenocorticotropin (ACTH), high-dose dexamethasone suppression, and corticotropin-releasing hormone stimulation testing, is integral to the differential diagnosis. No existing test has sufficient diagnostic accuracy when used alone, however. The adjunctive use of focused imaging, including CT, MRI, and nuclear imaging modalities, often can provide a diagnosis. In patients with ACTH-dependent CS, bilateral inferior petrosal sinus sampling can facilitate a diagnosis in those with discrepant clinical features, biochemistry, or imaging. This article focuses on current biochemical and radiologic strategies for the differential diagnosis of CS.

Cushing Syndrome↗
PubMed2005

Partial redirection of transgenic human growth hormone secretion from rat salivary glands.

Regulated secretory pathway proteins, when delivered as transgenes to salivary glands, are secreted predominantly into saliva. This is not useful for those proteins whose therapeutic function is required systemically, for example, human growth hormone (hGH). One strategy to improve the efficiency of hGH secretion into the bloodstream involves manipulation of existing sorting signals. The C terminus of hGH is highly conserved and contains a domain similar to the regulated pathway sorting domain of pro-opiomelanocortin (POMC). We hypothesized that, similar to POMC, mutation of this domain would divert hGH secretion from the regulated to the constitutive pathway, which in salivary glands leads to the bloodstream. Several mutations were made in the C terminus of the hGH cDNA and tested in vitro. One biologically active mutant containing E174A and E186A substitutions, and with an included C-terminal extension, was studied in greater detail. Compared with wild-type hGH, we found that this mutant hGH accumulated in the Golgi/trans-Golgi network and showed increased basal secretion in AtT20 cells, a model endocrine cell line. Importantly, in vivo, the mutant hGH displayed a relative increase in the proportion of constitutive pathway secretion seen from rat salivary glands, with a significantly lower saliva-versus-serum secretion ratio (p=0.03). Although this mutant is unlikely to be therapeutically beneficial, these results suggest that the final destination of a transgenic secretory protein may be controlled by reengineering its sorting determinants.

Adenoviridae↗
PubMed2005

Salivary glands as a potential gene transfer target for gene therapeutics of some monogenetic endocrine disorders.

Salivary glands (SGs) exhibit several important features which are also common to endocrine glands: self-containment due to a surrounding capsule, highly efficient protein production and the ability to secrete proteins into the bloodstream. We have hypothesized that SGs are potentially useful as gene transfer targets for the correction of inherited monogenetic endocrine disorders. In the present communication, we extend our studies and attempt to test our hypothesis by comparing the efficacy of two commonly used viral vectors and the resulting serum and salivary distribution of transgene encoded hormones. A low dose (5 x10(9) particles) of either an adenoviral serotype 5 (Ad5) vector encoding the human erythropoietin (hEPO) cDNA or an adeno-associated virus sero-type 2 (AAV2) vector encoding either the hEPO or human growth hormone (hGH) cDNA was administered to individual submandibular SGs of Balb/c mice. Serum and salivary hEPO and hGH levels were determined at defined time points. Two additional recombinant viruses encoding enhanced green fluorescence protein (GFP) were also used (AdGFP and AAVGFP) in order to perform immunohistochemical analyses of transgenic protein localization in SG sections post-administration. AAV2 vectors led to stable gene transfer unlike the results with the Ad5 vectors. Indeed, in one mouse we observed hEPO production for a period of two years after administration of AAVhEPO to SGs. hEPO, which is a constitutive pathway secretory protein, was readily secreted into the bloodstream from the SGs, yielding therapeutically adequate serum levels. Conversely, hGH, a regulated secretory pathway protein, was preferentially secreted into saliva. SGs may be an attractive candidate target tissue for gene therapeutics of some monogenetic endocrine deficiency disorders. At present, AAV2 vectors seem particularly useful for such applications, and transgenes encoding constitutive secretory pathway hormones are more suitable for this application with SGs than those encoding regulated secretory pathway hormones.

Adenoviridae↗
PubMed2004

Deficits in hippocampus-mediated Pavlovian conditioning in endogenous hypercortisolism.

BACKGROUND: Elevated endogenous levels of corticosteroids cause neural dysfunction and loss, especially within the hippocampus, as well as cognitive impairment in hippocampus-mediated tasks. Because Cushing's syndrome patients suffer from hypercortisolism, they represent a unique opportunity to study the impact of elevated glucocorticoids on cognitive functions. The aim of this study was to examine the performance of Cushing's syndrome patients on trace eyeblink conditioning, a cross-species, hippocampal-mediated test of learning and memory. METHODS: Eleven Cushing's syndrome patients and 11 healthy control subjects participated in an eyeblink trace conditioning test (1000-msec trace) and a task of declarative memory for words. Salivary cortisol was collected in both the patients and the control subjects, and urinary free cortisol was collected in the patients only. RESULTS: The patients exhibited fewer conditional responses and remembered fewer words, compared with the control subjects. Cortisol levels correlated with immediate and delayed declarative memory only. Conditional response correlated with delayed recall after controlling for the magnitude of unconditional response. CONCLUSIONS: The integrity of the hippocampus seems to be compromised in Cushing's syndrome patients. Trace eyeblink conditioning might be useful both as a clinical tool to examine changes in hippocampus function in Cushing's disease patients and as a translational tool of research on the impact of chronic exposure of glucocorticoids.

Adult↗
PubMed2004

Reengineered salivary glands are stable endogenous bioreactors for systemic gene therapeutics.

The use of critical-for-life organs (e.g., liver or lung) for systemic gene therapeutics can lead to serious safety concerns. To circumvent such issues, we have considered salivary glands (SGs) as an alternative gene therapeutics target tissue. Given the high secretory abilities of SGs, we hypothesized that administration of low doses of recombinant adeno-associated virus (AAV) vectors would allow for therapeutic levels of transgene-encoded secretory proteins in the bloodstream. We administered 10(9) particles of an AAV vector encoding human erythropoietin (hEPO) directly to individual mouse submandibular SGs. Serum hEPO reached maximum levels 8-12 weeks after gene delivery and remained relatively stable for 54 weeks (longest time studied). Hematocrit levels were similarly increased. Moreover, these effects proved to be vector dose-dependent, and even a dosage as low as 10(8) particles per animal led to significant increases in hEPO and hematocrit levels. Vector DNA was detected only within the targeted SGs, and levels of AAV copies within SGs were highly correlated with serum hEPO levels (r = 0.98). These results show that SGs appear to be promising targets with potential clinical applicability for systemic gene therapeutics.

Animals↗
PubMed2004

Reduced dermatopontin expression is a molecular link between uterine leiomyomas and keloids.

Uterine leiomyomas are prevalent estrogen-responsive clonal tumors, but the specific genetic alterations that contribute to their development have not been elucidated. To identify genes involved in the formation of leiomyomas, we used global expression profiling to compare clonal tumors with normal myometrium. Contrary to expectation, genes involved in estrogen action were not differentially expressed between leiomyoma and normal myometrium. Genes encoding extracellular-matrix proteins were prominently featured, suggesting their involvement in formation of a myofibroblast phenotype. Analysis of the extracellular matrix in the leiomyomas revealed a disordered collagen fibril orientation. Expression of the collagen-binding protein dermatopontin was found to be consistently decreased in leiomyoma by both reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR (mean underexpression = 9.41-fold) regardless of leiomyoma size, leiomyoma location, patient race, and patient age. This expression pattern was observed in 11 subjects and a total of 23 leiomyoma:myometrium pairs. Decreased expression of dermatopontin was also associated with keloid formation, a fibrotic disease that shares epidemiologic similarities with leiomyoma. Immunohistochemical studies of leiomyomas and keloids demonstrated reduced levels of dermatopontin in both tissues. In addition, ultrastructural analysis revealed that the orientation of the collagen fibrils in the keloid tissues strongly resembled that in the leiomyomas. Reduction in dermatopontin was associated with an increase in transforming growth factor-beta3 (TGFB3) mRNA levels in leiomyomas, whereas other genes involved in dermatopontin signaling were not differentially expressed. These findings suggest that leiomyoma development involves a myofibroblast cell phenotype characterized by dysregulation of genes encoding extracellular-matrix proteins. In particular, decreased expression of dermatopontin represents a molecular link between the leiomyoma and keloid phenotypes.

Adult↗