Growth deceleration and bone metabolism in nutritional dwarfing rats

Nutritional status as well as energy and protein intake are critical regulators of IGF-1 and IGFBP-3 and contribute to the modulation of bone remodeling and formation. The purpose of this study was to investigate on an experimental model with nutritional dwarfing (ND), whether the alterations on body growth velocity, energy metabolism and body composition could affect serum concentrations of IGF-1 and IGFBP-3 and bone (tibiae and mandible) histology and histomorphometry. Twenty-one male weanling Wistar rats (body weight = 38.20 +/- 0.94 g) were randomized to three groups: seven of them were killed at day = 0 (CO, n = 7); control (C, n = 7); and experimental 80 (E80, n = 7). During 4 weeks, C was fed ad libitum with a 1:1 carbohydrate to fat diet. E80 was being underfed with the same diet by 80% and the following parameters were measured: weight (Wt) for length (L) ratio z-score; oxygen consumption (VO2); body composition (BC) by EM-SCAN SA 3000. At t = 28, E80 and C were killed. Serum IGF-1 and IGFBP-3 and bone histology and histomorphometry were performed on C0, E80 and C. E80 showed Wt for L z-score between lean and adequate, a decrease in VO2 according to body proportions, a BC of a delayed puberty individual, IGF-1 and IGFBP-3 decreased by 56 and 53%, respectively. Tibiae's hematopoyetic and adipose bone marrow areas were combined, with sealing trabeculae on metaphyseal areas. This study suggests that there is a relationship among growth deceleration in ND rats and structural alterations on tibiae.

Overexpression of connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 decreases bone density in adult mice and induces dwarfism

Connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24) is a multifunctional growth factor for fibroblasts, chondrocytes, and vascular endothelial cells. In the present study, we established transgenic (Tg) mice that overproduce CTGF/Hcs24 under the control of mouse type XI collagen promoter. Tg mice could develop and their embryonic and neonatal growth occurred normally. But they showed dwarfism within a few months of birth. X-ray analysis revealed that their bone density was decreased compared with normal mice. The femurs in the hindlimbs in particular showed an apparent low density. These results indicated that overexpression of CTGF/Hcs24 affects certain steps of endochondral ossification. In addition, the testes were much smaller than normal and fertility was affected in Tg mice, indicating that CTGF/Hcs24 may also regulate the embryonic development of the testis.

The behavior profile of children and adolescents with short stature

The relation between behavior profiles and short stature was assessed in 311 children and adolescents with various diagnoses. The mean Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) profile of the entire group of children with growth deficiency significantly exceeded population norms on all scales and scores. However, there were no significant differences between five major diagnostic groups across CBCL scales. Neither age, gender, socioeconomic status, nor severity of short stature had any effect on the various CBCL and YSR scores. Correlations between parent (CBCL) and child (YSR) scores were significant, though only at a low to medium level. It was concluded that probably short stature per se, rather than a specific diagnosis, has an impact on behavioral adaptation.

Robinow syndrome with growth hormone deficiency: treatment with growth hormone

We describe a 5 years and nine months old boy who presented with facial features, vertebral anomalies and dwarfism consistent with Robinow syndrome. Investigations revealed growth hormone (GH) deficiency to be the cause of his dwarfism. We reviewed data on four other patients with Robinow syndrome from the Genentech National Cooperative Growth Study (NCGS). Results of GH testing on three out of four were available and showed GH deficiency. Recombinant human GH therapy in our patient and the three patients from the NCGS resulted in a significant increase in the growth rate per year. The cause of dwarfism in children with Robinow syndrome has hitherto not been studied. We propose its association with GH deficiency and that treatment with rhGH can result in a significant increase in the growth rate of these children.

From Horus the child to Hephaestus who limps: a romp through history

The question of why Hephaestus, the Greek god of smiths, limped has been the subject of much debate, mainly on mythological grounds. This debate extended also into the field of medical diagnosis, with attempts at defining the nature of the deformity that made the crippled Hephaestus the buffoon of the other Olympic gods. One problem encountered in these debates was the changes to which the ugly young Hephaestus was subjected with the passing of time-from a limping deformed youth to the later dignified and normal man. While some authors, largely influenced by poetic Greek texts and vase paintings, attributed the limp to talipes (club-feet), others pointed to certain features suggestive of achondroplasia. Since the image of the early Hephaestus is based mainly on the much earlier concept of the Egyptian god Ptah, who as the triune god of the resurrection sometimes is depicted as an achondroplastic dwarf (Ptah-Pataikos), the suggestion of the possible achondroplastic dwarf-like nature of the early Hephaestus is not implausible. It is supported by similarities in the image of Hephaestus to some features in other Egyptian gods, such as the domestic god Bes, the guardian of the new-born, and the Horus the Child or Harpocrates (Greek), yet another protector of youth and "the symbol of everything that is young and vigorous" [Budge, 1969: The Gods of the Egyptians, or Studies in Egyptian Mythology. Volume I.]. The characteristic feature of this child-god is the "lock of Harpocrates" on the right side of his head. That this lock can sometimes also be seen not only on the head of Ptah-Pataikos and of Bes but also on the young Hephaestus is highly suggestive of the Egyptian influence on his image. Recently, however, another interesting explanation of Hephaestus's limp has been suggested that may explain why the Egyptian influenced image of the early achondroplastic Hephaestus changed to the later, more Grecian view of the smith-god who hobbled because of club-feet. Improvements in composition-analysis of samples from antique statues and various utensils have led to the suggestion that the introduction of new smelting techniques in antique times may have exposed ancient metal workers to the effects of various toxic metals causing, for instance, chronic lead poisoning or, more relevant here, chronic arsenic poisoning causing peripheral neuritis with weakness and lameness of one or both lower extremities. Later changes in smelting technique, and recognition or guess-work of a possible connection between these techniques and toxic effects, may explain the change from the buffoon-like achondroplastic walk to the club-footed limp and eventual normal behaviour of Hephaestus, the Smith. In other words: Did Hephaestus limp because of his arsen-neuritis?

A Lys644Glu substitution in fibroblast growth factor receptor 3 (FGFR3) causes dwarfism in mice by activation of STATs and ink4 cell cycle inhibitors

Missense mutations of human fibroblast growth factor receptor 3 (FGFR3) result in several skeletal dysplasias, including hypochondroplasia, achondroplasia and thanatophoric dysplasia. To study the function of FGFR3 in bone growth and to create animal models for the FGFR3-related inherited skeletal disorders, we introduced a point mutation (Lys644Glu) into the murine FGFR3 genome using a knock-in approach. We found that the Lys644Glu mutation resulted in retarded endochondral bone growth with severity directly linked to the expression level of the mutated Fgfr3. Mice heterozygous for the mutation ( Fgfr3(TD/+) ) expressed the mutant allele at approximately 20% of the wild-type level and exhibited a mild bone dysplasia. However, when the copy number of the mutant allele increased from one (Fgfr3(TD/+) to two (Fgfr3(TD/TD), the retardation of bone growth became more severe and showed phenotypes resembling those of achondroplasia patients, characterized by a dramatically reduced proliferation of growth plate cartilage, macrocephaly and shortening of the long bones, which was most pronounced in the femur. Molecular analysis revealed that expression of the mutant receptor caused the activation of Stat1, Stat5a and Stat5b, and the up-regulation of p16, p18 and p19 cell cycle inhibitors, leading to dramatic expansion of the resting zone of chondrocytes at the expense of the proliferating chondrocytes. The mutant growth plates consequently were in a less active state and generated fewer maturing and hypertrophic chondrocytes. These data provide direct genetic evidence that the point mutations in FGFR3 cause human skeletal dysplasias and uncover a mechanism through which the FGFR3 signals regulate bone growth by modulating expression of Stats and ink4 cell cycle inhibitors.

[Clinical study of neurofibromatosis type 1]

INTRODUCTION

Recklinghausen's disease is considered to be the autosomal dominant disorder with the highest rate of mutation after achondroplasia. It is a neuroectodermal disorder with considerable clinical effects.

PATIENTS AND METHODS

We present a study of 14 patients seen for café-au-lait spots in the Clinical Genetics Department of the Hospital Infantil Sur. A detailed questionnaire and physical examination was done to obtain a clinical outline.

CONCLUSION

Suspicion of this condition, together with laboratory investigations led to the conclusion that the cases were neurofibromatosis.

Costello syndrome: phenotype, natural history, differential diagnosis, and possible cause

We describe 8 patients affected with Costello syndrome including an affected sib pair and review the literature on 29 previously reported cases. We emphasize an association with advanced parental age, which is consistent with autosomal dominant inheritance with germline mosaicism. The pathogenesis appears to involve metabolic dysfunction, with growth disturbance, storage disorder appearance, acanthosis nigricans, hypertrophic cardiomyopathy, and occasional abnormalities of glucose metabolism. Although the cause is currently unknown, Costello syndrome is interesting because of a potential genetic-metabolic etiology.

[Nutrition dwarfism: longitudinal analysis of anthropometric and metabolic parameters in rats]

Nutritional dwarfing (ND) is the result of nonorganic causes reflective of a voluntary or unintentional reduction in food intake, inappropriate eating behavior, dissatisfaction with body weight or unhealthy approaches toward weight control. Patients with ND have reached an equilibrium between their genetic growth potential and their nutritional intake. This study was undertaken to compare on a growing rat model the metabolic alterations in terms of substrate utilization (SU), oxygen consumption (VO2) and growth rate velocity. Twenty male weanling Wistar rats were randomized to 3 groups: control (C), experimental 4 (E4) and 8 (E8). C was fed "ad libitum" with a stock diet, E4 and E8 were underfed by 80% of the requirements during four or eight weeks, respectively. During the depletion phase the following measurements were performed: 1a) body weight (Wt), 1b) length, 1c) Weight for Length ratio z-score, 2) Body composition (BC) by EM-SCAN Tobec Model 3 000, Springfield. USA, 3) VO2 by indirect calorimetry, ECO-OXYMAX.

RESULTS

1) wt for length was -0.70 +/- 0.43 for E4 (t = 4 weeks) and 1.44 +/- 0.32 for E8 (t = 8 weeks), 2% of fat mass was within the normal range, 3) VO2 was not significantly different between groups. Chronic suboptimal nutrition (80%) decreased growth velocity which was the sole manifestation of nutritional inadequacy.

Dwarfism and gigantism in historical picture postcards

A collection of 893 historical picture postcards from 1900 to 1935, depicting dwarfs and giants, was analysed from medical and psychosocial viewpoints. In conditions such as 'bird headed dwarfism', achondroplasia, cretinism, so-called Aztecs or pinheads, Grebe chondrodysplasia, and acromegalic gigantism, the disorder could be diagnosed easily. In hypopituitary dwarfism, exact diagnosis was more difficult because of heterogeneity. The most common conditions depicted were pituitary dwarfism and achondroplasia. Most of those with gigantism had pituitary gigantism and acromegaly. Brothers and sisters or parents and their children provided evidence of mendelian inheritance of some of these disorders. The cards suggest that being put on show provided, at least in some cases, social benefits.

[Chronic giardiasis with intestinal dwarfism and delayed puberty in immunoglobulin deficiency syndrome: complete catch-up growth after therapy]

A 10-year-old, previously healthy Swiss boy suffered from repeated episodes of watery diarrhea for some months following a summer camp holiday. No etiology was found, and except for symptomatic treatment no other therapy was necessary. Five years later he was investigated because of growth failure, with a bone age of 11.5 years, but the correct diagnosis was not established. Only when he was reinvestigated at the age of 20 years, because of persistent growth failure and a bone age of 14 years, were Giardia lamblia trophozoites seen microscopically on the surface of duodenal mucosa biopsy specimens. At the same time dysgammaglobulinemia was detected which may have predisposed the gastrointestinal tract to chronic giardiasis. After a 10-day course of metronidazole the patient experienced catch-up growth and completed his pubertal development. The dysgammaglobulinemia persisted after therapy. This case showed that in patients with intestinal growth failure, catch-up growth and completion of pubertal development are possible even after the age of 20 years if nutritional supply is sufficient. Bone age determinations serve to indicate remaining growth potential.

Growth impairment and growth hormone therapy in children treated for malignant brain tumours

Eighty-two children with malignant brain tumours were treated according to the "8 in 1" chemotherapy protocol in Finland during 1986 to 1993. Thirty-seven with brain tumours not involving the hypothalamic-pituitary region are still alive and tumour-free. The growth and response to growth hormone (GH) therapy in these children was analysed. Children who received craniospinal irradiation had the most severe loss of height SDS, being -1.07 within 3 years of the diagnosis. Even children with no irradiation to the hypothalamic-pituitary axis had a mean change in height SDS of -0.5 after 3 years. Fifteen of 23 children who received craniospinal irradiation and two out of eight children who received cranial irradiation have received GH therapy. A catch-up growth response to the daily GH therapy with the mean dose of 0.7 IU/kg per week was complete in 3 years (+1.87 SDS), irrespective of craniospinal irradiation, in children who were treated at prepubertal age but was seen in none of the children who had reached pubertal age.

CONCLUSION

Growth impairment and GH deficiency are common in children treated for malignant brain tumours. The response to GH therapy is good in prepubertal children in terms of increased growth velocity, although the final height is not yet known.

Short- and long-term (final height) data in children with normal variant short stature treated with growth hormone

Seventeen children with normal variant short stature and a predicted height below -2 SDS were treated with growth hormone (GH) six times a week for a period of 5 years. Patients were randomly selected to receive three different doses of GH, group 1 (n = 6) 3 IU/m2 per day, group 2 (n = 6) 4.5 IU/m2 per day and group 3 (n=5) 3 IU/m2 per day in the 1st year and 4.5 IU/m2 per day thereafter. There was a significant increase in height after 1 and 2 years for all patients and for all subgroups. However, this increase was not dependent on GH dose. The decrease in height velocity during the 2nd year was not prevented by the increase of GH dose in group 3. The change of predicted height after 2 years was +0.75 SDS (according to Tanner Whitehouse). Fourteen children have been treated for 4 years and 8 children for 5 years without a further change in height prediction. Nine patients have reached final height which was 2.4 cm (+0.41 SDS) above pretreatment height prediction. Final height was nearly identical to predicted height after 1 year of therapy.

CONCLUSION

An increment in height prediction was observed during the first 2 years of GH treatment and maintained thereafter. However, there was only a minor increase in final height over predicted height which does not justify the general use of GH in children with normal variant short stature.