RESUMEN
Diastrophic dysplasia (DTD) is an autosomal recessive skeletal dysplasia caused by SLC26A2 mutations. Clinical features include short stature, joint contractures, spinal deformities, and cleft palate. SLC26A2 mutations also result in other skeletal dysplasias, including the milder recessive multiple epiphyseal dysplasia (rMED). DTD is overrepresented in Finland and we speculated that this may have influenced the prevalence and spectrum of SLC26A2-related skeletal conditions also in Sweden. We reviewed the patient registry at Department of Clinical Genetics, Karolinska University Hospital, Stockholm to identify subjects with SLC26A2 mutations. Seven patients from six families were identified; clinical data were available for six patients. All but one patient had one or two copies of the Finnish SLC26A2 founder mutation IVS1+2T>C. Arg279Trp mutation was present in compound heterozygous form in five patients with phenotypes consistent with rMED. Their heights ranged from -2.6 to -1.4 standard deviation units below normal mean and radiographic features included generalised epiphyseal dysplasia and double-layered patellae. Two rMED patients had hypoplastic C2 and cervical kyphosis, a severe manifestation previously described only in DTD. Our study confirms a high prevalence of rMED in Sweden and expands the phenotypic manifestations of rMED.
Asunto(s)
Proteínas de Transporte de Anión/genética , Mutación , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/genética , Alelos , Huesos/patología , Niño , Preescolar , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Fenotipo , Estudios Retrospectivos , Transportadores de Sulfato , SueciaRESUMEN
OBJECTIVE: To characterise early growth and neurocognitive development in children of mothers with a history of eating disorders (ED). DESIGN: A longitudinal cohort study. SETTING: Child-care centres in Stockholm, Sweden. POPULATION: Children born to mothers with previous ED (n = 47) (24 anorexia nervosa, 20 bulimia nervosa, 3 unspecified ED), and controls (n = 65). METHODS: Mean values and standard deviation scores of weight and height from birth to 5 years of age and head circumference up to 18 months of age were compared between groups. Neurocognitive development was studied at the age of 5 years by the validated parent questionnaire Five to Fifteen. MAIN OUTCOME MEASURES: Head growth and neurocognitive development. RESULTS: We previously reported that mothers with a history of ED conceived infants with lower birthweight and head circumference than controls. At 3 months of age, body mass index (BMI) was no longer reduced but mean head circumferences of the children born to mothers with ED were smaller throughout the observation period. Similarly, the longitudinal results of the standard deviation scores of head circumference showed a significant overall group effect with lower levels in both subgroups of ED (anorexia nervosa and bulimia nervosa). The children of the ED mothers also had significantly higher Five to Fifteen scores than controls, reflecting difficulties in language skills. Head circumference at birth correlated with language skills in the children of mothers with ED. CONCLUSION: Children of mothers with previous ED demonstrated an early catch-up in BMI, but the average head circumference continued to be delayed until at least 18 months of age. The reduced head growth was related to delayed neurocognitive development.
Asunto(s)
Cefalometría , Trastornos de Alimentación y de la Ingestión de Alimentos/epidemiología , Trastornos del Desarrollo del Lenguaje/epidemiología , Cráneo/crecimiento & desarrollo , Adulto , Peso al Nacer , Estudios de Casos y Controles , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Estudios Longitudinales , Embarazo , Conducta Social , Encuestas y Cuestionarios , Suecia/epidemiologíaRESUMEN
AIM: To provide growth charts for clinical monitoring of extra-uterine growth from birth to full-term age, in infants born before 26 weeks of gestation, hospitalized at neonatal intensive care unit (NICU), and compare it to the commonly used Swedish preterm birth-size reference. METHODS: This retrospective longitudinal cohort comprised all infants born before 26 + 0 weeks of gestation and surviving to full-term age (n = 162), admitted to the NICU, Karolinska Hospital during the period January 1990 to December 2002. Body weight was recorded daily, head circumference (HC) weekly and length twice a month. RESULTS: Birth weight (BW), length and HC showed a normal distribution without significant gender difference. The majority of the infants showed a pronounced postnatal growth restriction for all growth variables with increasing deviation from the reference with age. The mean initial weight loss was 16% with nadir at 6 days of age and a mean time to regain BW of 18 days. At discharge from NICU, 75% of those initially appropriate for gestational age infants were below -2 standard deviation scores for at least one of the body size variables. CONCLUSION: The poor extra-uterine growth pattern points to the need of growth curves for extra-uterine growth of extremely premature infants.
Asunto(s)
Gráficos de Crecimiento , Recien Nacido Prematuro/crecimiento & desarrollo , Estatura , Peso Corporal , Femenino , Edad Gestacional , Cabeza/crecimiento & desarrollo , Humanos , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Estudios Longitudinales , Masculino , Modelos Estadísticos , Estudios Retrospectivos , SueciaRESUMEN
An immunologically anomalous LH with two point mutations in its beta-subunit gene (Trp8Arg and Ile15Thr) has recently been described. This polymorphism is common in Finland; 28% of the population are homo- or heterozygous for the variant allele. To assess the effect of the LH variant on LH action, we correlated its presence in a group of 49 healthy boys with the onset and progression of puberty. This group was followed-up longitudinally from a mean age of 11.7 +/- 0.1 yr for 3 yr at 3-month intervals. In addition, we studied the prevalence of the variant LH in boys with constitutional pubertal delay (testicular volume < or = 4 mL after 13.5 yr of age). The LH beta gene status of each subject in this study was judged from a single venous blood sample using two immunofluorometric LH assays with different combinations of monoclonal antibodies: one detecting both the variant and wild-type LH, and the other detecting only wild-type hormone. Of the boys with pubertal onset at a normal age, 36 (74%) were homozygous for the wild-type LH beta allele, 12 (24%) were heterozygous, and 1 (2%) was homozygous for the variant LH beta allele. Clear differences in pubertal parameters were found between the boys with normal and mutated (homo- or heterozygous) LH genotypes. During the follow-up, the boys with the mutated genotype had smaller testicular volumes (P < 0.03), were shorter (P < 0.02), had slower growth rates (P < 0.04), and had lower serum insulin-like growth factor I-binding protein-3 levels (P < 0.03) than the boys with the normal LH genotype. In the boys with delayed onset of puberty, the frequency of the variant LH beta allele did not differ from that in the reference population, indicating that the variant LH is not associated with conditions due to disturbed control of the reactivation of GnRH secretion. We conclude that during the progression of puberty, the variant LH may be less active in stimulating testicular growth than wild-type LH. Thus, the gene may affect tempo, contributing to the wide normal variation in pubertal progression in healthy boys. Our results also suggest that the variant LH not only affects the course of puberty, but is already involved in the regulation of the GH-insulin-like growth factor I axis during childhood.
Asunto(s)
Hormona Luteinizante/genética , Polimorfismo Genético , Pubertad/genética , Adolescente , Estatura , Niño , Finlandia , Hormona Folículo Estimulante/sangre , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Hormona Luteinizante/sangre , Masculino , Pubertad Tardía/genética , Globulina de Unión a Hormona Sexual/metabolismo , Testosterona/sangreRESUMEN
The spontaneous growth process in Turner's syndrome is characterized by a progressive decline in height velocity during childhood and no pubertal growth spurt. Therefore, therapy aimed at improving height during childhood as well as increasing final height is desirable for most girls with Turner's syndrome. Forty-five girls with Turner's syndrome, 9-16 yr of age (mean age, 12.2 yr), were allocated to three study groups. Group 1 (n = 13) was initially treated with oxandrolone alone; after 1 yr of treatment, GH without (group 1a; n = 6) or with (group 1b; n = 7) ethinyl estradiol was added. Group 2 (n = 17) was treated with GH plus oxandrolone. Group 3 (n = 15) was treated with GH, oxandrolone, and ethinyl estradiol. The dosage were: GH, 0.1 IU/kg.day; oxandrolone, 0.05 mg/kg.day; and ethinyl estradiol, 100 ng/kg.day. A height of 150 cm or more was achieved in 61%, 75%, and 60% of the girls in groups 1, 2, and 3, respectively. The most impressive increase in height was seen in group 2. In this group the mean final height was 154.2 cm (SD = 6.6), which is equivalent to a mean net gain of 8.5 cm (SD = 4.6) over the projected final height. In group 3, in which ethinyl estradiol was included from the start of therapy, the initially good height velocity decelerated after 1-2 yr of treatment. Their mean final height was 151.1 (SD = 4.6) cm, equivalent to a mean net gain of 3.0 cm (SD = 3.8). A similar growth-decelerating effect of ethinyl estradiol was seen in group 1b. We conclude that in girls with Turner's syndrome who are older than 9 yr of age, treatment with GH in combination with oxandrolone results in significant growth acceleration, imitating that in normal puberty, leading to a more favorable height during childhood. This mode of treatment also results in a significantly increased final height, permitting a great number of the girls to attain a final height of more than 150 cm. However, early addition of estrogen decelerates the height velocity and reduces the gain in height.
Asunto(s)
Anabolizantes/uso terapéutico , Estatura , Hormona del Crecimiento/uso terapéutico , Oxandrolona/uso terapéutico , Síndrome de Turner/tratamiento farmacológico , Adolescente , Determinación de la Edad por el Esqueleto , Niño , Etinilestradiol/uso terapéutico , Femenino , Humanos , Síndrome de Turner/fisiopatologíaRESUMEN
BACKGROUND: The hormone leptin, produced in the adipose tissue, is involved in the regulation of body weight. The release of the hormone is increased in obese adults and decreased after fasting in human adults. This study investigated whether the plasma leptin level was related to the infant's birth weight and whether the level was reduced in connection with the physiological weight loss during the neonatal period. METHODS: We measured the plasma leptin level in cord blood from infants who were large for gestational age (LGA) (n = 15), small for gestational age (SGA) (n = 16), and appropriate for gestational age (AGA) (n = 38). AGA infants (n = 120), who were exclusively breastfed, were also studied during their first 4 postnatal days in a cross-sectional method. One blood sample was collected before breastfeeding from each infant. Plasma leptin concentrations were determined by radioimmunoassay. RESULTS: The median (range) concentration of leptin from cord blood was increased in LGA infants and decreased in SGA infants compared with the level in AGA infants. There was a positive correlation between the log of the plasma leptin level in cord blood and both the infant's birth weight (r = 0.76; n = 69) and the body mass index (r = 0.63; n = 69). The normal 3% to 6% weight reduction that occurs during the first 4 postnatal days was associated with a 26% decrease in the plasma leptin level in healthy breastfed infants. CONCLUSIONS: The plasma leptin level is highly correlated to the size of adipose tissue mass and decreases in connection with the initial physiological weight loss in newborn infants. These data provide evidence that leptin is highly related to the nutritional status already during the fetal and neonatal periods.
Asunto(s)
Recién Nacido/sangre , Proteínas/metabolismo , Pérdida de Peso/fisiología , Tejido Adiposo , Índice de Masa Corporal , Lactancia Materna , Estudios Transversales , Femenino , Macrosomía Fetal/sangre , Humanos , Recién Nacido Pequeño para la Edad Gestacional/sangre , Leptina , Masculino , Proteínas/análisisRESUMEN
To study the hormonal dependence of the blood-testis barrier, adult rats were hypophysectomized and the ultrastructural integrity of the inter-Sertoli cell junctional complex was examined at various times with a lanthanum tracer technique. It was found that the structural integrity of the inter-Sertoli cell junctions and their capacity to exclude lanthanum from the adluminal compartment were preserved up to 35 days after hypophysectomy. Furthermore, transport of newly formed spermatocytes through the inter-Sertoli cell junctions still occurred 20 days after hypophysectomy. It is therefore concluded that the function of the inter-Sertoli cell junctional complex is not directly dependent on gonadotrophic or androgenic hormones, but is regulated by other mechanisms.
Asunto(s)
Barrera Hematotesticular , Hipofisectomía , Células de Sertoli/ultraestructura , Animales , Uniones Intercelulares/ultraestructura , Lantano/metabolismo , Masculino , Ratas , Testículo/metabolismoRESUMEN
The production of testicular androgen-binding protein (ABP), as a measure of Sertoli cell function, was studied after unilateral or bilateral experimental cryptorchidism in adult rats. Two or 4 weeks after the testis had been translocated to the abdomen, no major changes were found in the concentration of ABP per mg protein, although there was a marked and progressive decrease in ABP content per testis. However, the rate of ABP production was greatly decreased, as measured by the accumulation of ABP during 16-h ligation of the efferent ducts or by the production of ABP by testis mince in an in vitro system. This indicates that the Sertoli cell function is severly impaired by the intra-abdominal position.
Asunto(s)
Criptorquidismo/metabolismo , Proteínas/metabolismo , Receptores de Superficie Celular , Células de Sertoli/metabolismo , Testosterona/metabolismo , Animales , Sitios de Unión , Epidídimo/metabolismo , Masculino , Unión Proteica , Ratas , Escroto/metabolismo , Testículo/metabolismoRESUMEN
In this report it is suggested that the specific adrogen-binding protein (ABP), previously shown to originate in the testis of rat and other species, is produced by the Sertoli cells. This suggestion is based upon the following experimental findings: 1) ABP was found in high concentrations in testicular efferent duct fluid but only in trace amounts in inter-tubular lymph. i) ABP could be recovered from crude preparations of testis tubules, but not from Leydig cells from the same testes. 3) Testes whose germinal epithelium had been severly damaged by gamma irradiation showed no decrease in ABP content. The transport of ABP to epididymis was also preserved as judged from the levels of ABP in caput epididymis. 4) Testes that were completely devoid of germ cells following prenatal gamma irradiation showed high levels of ABP, These high levels approached zero following hypophysectomy, but could be restored by FSH administration to the hypophysectomized animals. ABP has been well characterized and now provides a valuable experimental tool as an indicator of Sertoli cell function.
Asunto(s)
Proteínas Portadoras/metabolismo , Dihidrotestosterona/metabolismo , Células de Sertoli/metabolismo , Testículo/metabolismo , Animales , Epidídimo/ultraestructura , Epitelio/efectos de la radiación , Hormona Folículo Estimulante/farmacología , Células Germinativas/metabolismo , Hipofisectomía , Células Intersticiales del Testículo/metabolismo , Linfa/análisis , Masculino , Hipófisis/fisiología , Efectos de la Radiación , Ratas , Testículo/efectos de la radiación , Testículo/ultraestructura , Conducto Deferente/análisisRESUMEN
Testicular tissue from immature and adult rats shows in vitro synthesis of androgen-binding protein (ABP). The ABP synthesis is dependent on a complete tissue culture medium, the incubation temperature and the age of the rats. ABP synthesis is inhibited at 0 degrees C or in the presence of cycloheximide, puromycin or sodium fluoride. Immature (17-25-day-old rat) testes showed a higher rate of ABP synthesis per 100 mg tissue than adult rat testes during 'baseline' conditions (no additions to the medium). Addition of NIH-FSH-S10 or testosterone to the medium increases the production of ABP by the testicular minces. The in vitro techniques have proved to be useful for studies of direct hormonal influence on the Sertoli cell protein synthesis.
Asunto(s)
Receptores Androgénicos/metabolismo , Receptores de Esteroides/metabolismo , Testículo/metabolismo , Envejecimiento , Animales , Células Cultivadas , Cicloheximida/farmacología , Fluoruros/farmacología , Hormona Folículo Estimulante/farmacología , Cinética , Hormona Luteinizante/farmacología , Masculino , Puromicina/farmacología , Ratas , Receptores Androgénicos/efectos de los fármacos , Testículo/efectos de los fármacos , Testículo/crecimiento & desarrollo , Testosterona/metabolismo , Xantinas/farmacologíaRESUMEN
Several studies have now been published on the effect of one or several years of growth hormone treatment on growth and body composition of children with Prader-Willi syndrome. The majority of the patients have responded with greatly increased growth rate, decreased body fat and increased muscle volume. Many of these children seem to have a functional growth hormone deficiency, probably secondary to their hypothalamic dysfunction. Further studies are needed to establish the long-term effect of this treatment on somatic and psychological well-being.
Asunto(s)
Hormona de Crecimiento Humana/uso terapéutico , Síndrome de Prader-Willi/tratamiento farmacológico , Composición Corporal/efectos de los fármacos , Estatura/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Niño , Terapia de Reemplazo de Hormonas/efectos adversos , Terapia de Reemplazo de Hormonas/psicología , Hormona de Crecimiento Humana/efectos adversos , Hormona de Crecimiento Humana/deficiencia , Hormona de Crecimiento Humana/farmacología , Humanos , Hipercapnia/complicaciones , Hipercapnia/tratamiento farmacológico , Hipoventilación/complicaciones , Hipoventilación/tratamiento farmacológico , Síndrome de Prader-Willi/complicaciones , Síndrome de Prader-Willi/fisiopatología , Síndrome de Prader-Willi/psicologíaRESUMEN
A controlled, randomized study was conducted to assess the effect of growth hormone (GH) treatment on growth, body composition and behaviour in prepubertal children (3-12 years of age) with Prader-Willi syndrome. GH treatment was given to one group of 15 patients (group A) at a dose of 0.1 IU/kg/day for 2 years. The second group (group B; n = 12) was not treated for the first year and was then given GH at a dose of 0.2 IU/kg/day for the second year. All patients had low 24-hour levels of GH and insulin-like growth factor I before GH treatment. Height velocity SDS increased from -1.9 +/- 2.0 to 6.0 +/- 3.2 during the first year of GH treatment in group A, and from -1.4 +/- 1.2 to 10.1 +/- 3.9 in the second year of the study in group B. When GH treatment was stopped, height velocity declined dramatically. Height SDS followed a similar pattern. GH treatment reduced the percentage body fat and increased the muscle area of the thigh. Isometric muscle strength was also increased. In addition, GH treatment appeared to have psychological and behavioural benefits, which were reversed after cessation of treatment. It was concluded that GH treatment improves growth, body composition and behaviour in children with Prader-Willi syndrome.
Asunto(s)
Hormona de Crecimiento Humana/uso terapéutico , Síndrome de Prader-Willi/tratamiento farmacológico , Estatura/efectos de los fármacos , Niño , Conducta Infantil/efectos de los fármacos , Preescolar , Crecimiento/efectos de los fármacos , Hormona de Crecimiento Humana/sangre , Humanos , MasculinoRESUMEN
This paper reports results from an ongoing, randomized, multicentre national trial. The aim is to elucidate whether a dose of growth hormone (GH) of 0.2 IU/kg (0.07 mg/kg), given either as once-daily or twice-daily injections during puberty, is more effective than a once-daily dose of 0.1 IU/kg/day (0.03 mg/kg/day) in improving final height in children with GH deficiency (GHD). The twice-daily regimen comes closer to the spontaneous GH secretion pattern in puberty. Ninety-two children with GHD who had been receiving GH therapy for at least 1 year, and with spontaneous puberty or who were prepubertal and due to be started on replacement therapy to induce puberty, were randomly assigned to receive GH as follows: group A, 0.1 IU/kg/day (0.03 mg/kg/day), administered once daily; group B, 0.2 IU/kg/day (0.07 mg/kg/day), administered once daily; and group C, 0.2 IU/kg/day (0.07 mg/kg/day), divided into two equal injections given at 12-hour intervals. Pubertal height gain was 0.7, 0.7 and 1.3 SDS for groups A, B and C, respectively. The gain in height during puberty was thus most marked in group C. Mean final height, when corrected for parental height, was between 0 and 1 SDS in all treatment groups. All but seven children reached a final height within +/- 2 SD of the general population. There was a wide range of final heights in all three treatment groups. This variation in response suggests the need to individualize treatment in order to achieve an appropriate final height for most individuals.
Asunto(s)
Estatura/efectos de los fármacos , Trastornos del Crecimiento/tratamiento farmacológico , Hormona de Crecimiento Humana/administración & dosificación , Hormona de Crecimiento Humana/deficiencia , Adolescente , Niño , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Trastornos del Crecimiento/etiología , Humanos , Masculino , Pubertad/fisiología , Suecia , Resultado del TratamientoRESUMEN
Although Klinefelter's syndrome is the most common sex chromosome anomaly, affecting one in 5-800 boys, our knowledge of the syndrome is still poor. This is reflected in the paucity of published literature as compared, for example, with the vastly greater number of publications on Turner's syndrome with its lower incidence of 1/2,500 girls. Klinefelter's syndrome is manifestly underdiagnosed. Existing knowledge mainly derives from cases characterised by prominent symptomatology. Early diagnosis is important if additional support and resources are to be made available to the patient and his family. Testosterone replacement therapy should be initiated as soon as clinical and laboratory evidence becomes available. In selected cases, testosterone treatment can be started already during adolescence. At present, there is no established treatment for the infertility which almost always accompanies the condition.
Asunto(s)
Síndrome de Klinefelter/diagnóstico , Adulto , Baltimore , Niño , Historia del Siglo XX , Humanos , Lactante , Síndrome de Klinefelter/tratamiento farmacológico , Síndrome de Klinefelter/genética , Masculino , Diferenciación Sexual , Testículo/patología , Testosterona/administración & dosificación , Cromosoma XRESUMEN
BACKGROUND/AIMS: Fetal growth restriction is a complex problem of pregnancy arising from multiple etiologies. Key regulatory elements of growth are the insulin-like growth factor (IGF) axis, and estrogen and progesterone receptors. The aims were to determine the relations of expression of IGF-I, estrogen receptors α and ß (ERα and ERß, respectively), and progesterone receptor (PR), with maternal anthropometry, focusing on birth weight outcomes. METHODS: Placental samples were obtained from 33 patients following delivery. mRNA expression was determined by a solution hybridization technique. Samples were divided into normal control (NC) and growth-restricted (GR) groups. RESULTS: IGF-I expression was lower in the GR as compared to the NC group. PR levels correlated positively with IGF-I expression, infant anthropometry, and gestational age (GR). ERα correlated positively with PR expression (NC), and maternal BMI at delivery (GR). ERß correlated positively with maternal delivery weight and gestational age (NC). CONCLUSION: The differences in placental expression of IGF-I emphasize its key role in birth weight outcomes. We further suggest the importance of PR expression in the pathogenesis of intrauterine growth restriction, as there were direct correlations of PR expression with both IGF-I expression and infant anthropometric parameters, as well as gestational age.
Asunto(s)
Receptor alfa de Estrógeno/genética , Receptor beta de Estrógeno/metabolismo , Retardo del Crecimiento Fetal/genética , Factor I del Crecimiento Similar a la Insulina/genética , Placenta/metabolismo , Receptores de Progesterona/genética , Peso al Nacer/genética , Femenino , Humanos , Preeclampsia/fisiopatología , Embarazo , ARN Mensajero/metabolismoRESUMEN
PURPOSE: To analyze the metacarpophalangeal profile (MCPP) in individuals with Leri-Weill dyschondrosteosis (LWD) and to assess its value as a possible contributor to early diagnosis. MATERIAL AND METHODS: Hand profiles of 39 individuals with a diagnosis of LWD were calculated and analyzed. Discriminant analysis was applied to differentiate between LWD and normal individuals. RESULTS: There was a distinct pattern profile in LWD. Mean pattern profile showed two bone-shortening gradients, with increasing shortening from distal to proximal and from medial to lateral. Distal phalanx 2 was disproportionately long and second metacarpal was disproportionately short. Discriminant analysis yielded correct classification in 72% of analyzed cases. CONCLUSION: MCPP is not age-related and the analysis can be applied at any age, facilitating early diagnosis of LWD. In view of its availability, low costs, and diagnostic value, MCPP analysis should be considered as a routine method in the patients of short stature where LWD is suspected.
Asunto(s)
Deformidades Congénitas de la Mano/diagnóstico por imagen , Articulación Metacarpofalángica/diagnóstico por imagen , Osteocondrodisplasias/diagnóstico por imagen , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Diagnóstico Precoz , Femenino , Deformidades Congénitas de la Mano/genética , Humanos , Masculino , Cómputos Matemáticos , Persona de Mediana Edad , Osteocondrodisplasias/genética , Radiografía , Estudios Retrospectivos , Sensibilidad y Especificidad , SíndromeRESUMEN
A variety of heritable bone dysplasias have been identified, affecting a total of 3-4.5 in 10,000 new-born individuals. Many of these dysplasias affect fetal growth and growth during infancy, with linear growth and body proportions being affected. Taken together, the effects of such dysplasias often result in a reduced adult height. Currently, radiographic criteria are used to distinguish between different dysplasias. However, additional clinical findings are often required to make a specific diagnosis. Molecular and genetic techniques may also be used to confirm a particular diagnosis. However, the specific genetic defect underlying each disorder has yet to be identified for the majority of disorders.
Asunto(s)
Enfermedades del Desarrollo Óseo/fisiopatología , Crecimiento , Adulto , Estatura , Enfermedades del Desarrollo Óseo/clasificación , Enfermedades del Desarrollo Óseo/diagnóstico , Enfermedades del Desarrollo Óseo/diagnóstico por imagen , Enfermedades del Desarrollo Óseo/genética , Humanos , Recién Nacido , Radiografía , Valores de ReferenciaRESUMEN
In order to elucidate the mechanisms behind the deleterious effects on the germinal epithelium of experimental cryptorchidism the hypothesis that a leaking blood-testis barrier is the cause of the damage was tested. The permeability of the specialized inter-Sertoli cell junctions to lanthanum after experimental cryptorchidism for 0.5 to 12 days was studied in the rat. In none of the time periods studied lanthanum had penetrated beyond the inter-Sertoli cell junctions. A simple lanthanum immersion technique was used. Testes of 15-days old rats (before the development of the barrier) were used as a positive control of the method, and in these testes lanthanum had penetrated up to the future lumen.