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Biomedical subjects

J M Tanner

Publications and source records attributed to J M Tanner.

At least 19 recordsLinked to original sources
PubMed1995

Growth velocity monitoring of the efficacy of different therapeutic protocols in a group of thalassaemic children.

Since intensive chelating therapy for thalassaemic children was introduced, growth rates appear to have diminished. To investigate what factors were responsible we compared velocities of growth in length over a period of 1 year between groups distinguished by different strategies of treatment. Forty-two thalassaemic patients, 30 males aged 4-12 years, and 12 females, 4-10 years old, were assigned from their current treatment into subgroups based upon blood ferritin levels, daily dose of desferrioxamine and urinary zinc levels. CONCLUSION The results confirm that a reduction in desferrioxamine results in greater growth. If blood ferritin is low, the change effect may be greater. Secondly, any zinc deficiency should be treated. The changes in treatment convert a growth velocity of -2 to -3 SDS to a velocity of about -1 SDS.

Chelation Therapy↗
PubMed1994

A computerized image analysis system for estimating Tanner-Whitehouse 2 bone age.

A method for assigning Tanner-Whitehouse 2 skeletal maturity scores (or bone ages) to hand-wrist X-rays by an image analysis computer system is described. An operator positions the relevant area of the X-ray on a light box beneath a video camera. Correct positioning is assured by computer templates of each bone stage. Thereafter the process is automatic; the computer, not the operator, rates the bones. The system produces continuous stage scores, not discrete ones such as B, C or D. Data are given which show that the computer-assisted skeletal age score is more repeatable than the usual manual (or unassisted) rating. The absolute difference between duplicates averaged 0.25 stages; differences of as much as 1.0 stage occurred in only 3% of duplicates compared with 15% obtained in manual ratings.

Age Determination by Skeleton↗
PubMed1994

Reliability and validity of computer-assisted estimates of Tanner-Whitehouse skeletal maturity (CASAS): comparison with the manual method.

Three observers rated 57 X-rays from normal healthy children in Project HeartBeat! twice each by CASAS, the computer-assisted version of the TW2 RUS bone age method. Differences between duplicates of individual bone ratings which reached or exceeded 1.0 unit (or 1 stage) were 5% within observer and 8% between observers for CASAS, and 17 and 33%, respectively, for the unassisted MANUAL method. In children followed longitudinally, CASAS scores increased much more steadily than MANUAL scores, largely because the bones were rated, in the former system, on a continuous rather than a discrete-integer scale. We conclude that CASAS is a more reliable and probably a more valid estimator of skeletal maturity than the MANUAL version of the TW2 RUS method.

Adolescent↗
PubMed1994

Somatostatin analog treatment slows growth and the tempo of reproductive maturation in female rhesus monkeys.

The present study tested the hypothesis that a reduction in serum GH during adolescence would result in slower growth and delayed puberty. Skeletal growth and maturation as well as indices of reproductive development were studied in juvenile female rhesus monkeys receiving a constant sc infusion of a somatostatin analog, Sandostatin, at a dose of approximately 4.50 micrograms/kg BW.day (Ssa; n = 6) and in untreated females (Con; n = 6) from 18 months of age through the luteal phase of the second ovulation. Although age at menarche was similar in Con and Ssa females, first ovulation was delayed significantly in Ssa females, such that the interval between menarche and first ovulation was significantly longer in Ssa females. Serum concentrations of GH, insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 were reduced in Ssa females, particularly after menarche. Although changes in body weight were similar between Ssa and Con females, growth in height was significantly greater in Con females. Furthermore, peak growth velocity in height occurred at a significantly later age in SSa females, but at a similar degree of skeletal maturity. Serum insulin and glucose levels in response to iv glucose were similar in the two groups; however, fasting levels of serum glucose decreased significantly in both groups with advancing age, but the decrease was greater in Con. During the luteal phase of the first 2 ovulatory cycles, there were diminished serum progesterone in 16.7% (2 of 12) of the Con and 41.7% (5 of 12) of the Ssa females. Serum estradiol was significantly lower throughout the first 2 ovulatory cycles in Ssa females, whereas serum LH and IGF-I were similar to those in Con females. Multiple regression analyses revealed that age at menarche was best predicted from the amount of growth in height before menarche, whereas those females who had higher serum IGF-binding protein-3 levels before menarche had an earlier growth spurt, and those who grew faster had a shorter interval between menarche and first ovulation. These data indicate that treatment with a long-acting somatostatin analog, which produces a relative deficiency in the GH axis, slows growth and delays the tempo of puberty. The data suggest that this delay may be due to a reduction in gonadal sensitivity to LH.

Aging↗
PubMed1993

Neonatal treatment of male monkeys with a gonadotropin-releasing hormone agonist alters differentiation of central nervous system centers that regulate sexual and skeletal development.

Male rhesus monkeys treated continuously with a GnRH agonist for the first 4 months of postnatal life exhibited a delay in the onset of puberty and an attenuated peripubertal rise in testosterone (T) secretion. The objectives of the current study were to determine whether these effects on sexual development were permanent and whether the hypothalamic-pituitary-testicular axis was functioning normally in these animals as adults. Neonatal GnRH agonist treatment delays but does not permanently block sexual maturation in male monkeys. Treated animals that did not show a pubertal rise in serum T during the breeding season of their 4th year exhibited a seasonal but subnormal elevation of serum T during the subsequent breeding season. Growth of the skeleton was diminished as evidenced by shorter adult crown-rump, tibia, and femur length and reduced bone mineral density of the humerus and lumbar spine. The magnitude of the serum LH and T response to iv pulses of GnRH [50 ng/kg body weight (BW)] and naloxone (1 mg/kg BW) did not differ between control and treated animals during the nonbreeding or breeding season at 6 yr of age. Conversely, treated animals showed a subnormal serum LH and T response to N-methyl-D,L-aspartic acid (5 mg/kg BW iv) during the nonbreeding season. These data suggest that adult monkeys treated neonatally with a GnRH agonist exhibit subnormal sensitivity of the central nervous system to one or more excitatory amino acids (e.g. aspartate or glutamate). Thus, abolishing neonatal activation of the pituitary-testicular axis with a GnRH agonist may permanently alter differentiation of central nervous system centers that are either involved in GnRH secretion or govern this process.

Animals↗
PubMed1993

Constant low-dose oestradiol replacement accelerates skeletal maturation and growth in ovariectomized adolescent rhesus monkeys.

The effects of oestradiol (OE2) on adolescent growth in female rhesus monkeys were evaluated by testing the hypothesis that, upon removal of the ovary, the increase in growth normally seen at the time of puberty would be abolished and that treatment with OE2 would restore it. Juvenile monkeys (n = 12) were ovariectomized and were given either an OE2-bearing silicone elastomer capsule implanted subcutaneously to simulate mid-pubertal concentrations ('treated =', n = 8) or no steroid treatment ('control =', n = 4). Females were studied from 18 to 42 months of age which, in intact females, typically encompasses the prepubertal period to the occurrence of first ovulation. Over the whole period, growth in body weight, crown-rump (CR) length and tibia length for control females were less than the 95% confidence limits of females treated with OE2. However, significant spurts of growth in both CR and tibia length occurred in the control as well as treated animals, although the peak velocities were somewhat lower for non-OE2-treated animals. Peak growth velocities occurred at an earlier chronological age in treated females, although at the same degree of skeletal maturity as found in control females. Skeletal maturity was significantly advanced in treated females from 27 months onward. Serum concentrations of nocturnal GH increased significantly with advancing age in both groups, with greater increases observed in treated females. Serum concentrations of IGF-I were higher in treated females until some 30 months of age, at which point concentrations increased in a similar fashion in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Growth as a measure of the nutritional and hygienic status of a population.

The history of the use of children's growth as a measure of the nutrition and hygiene of a population since the early 19th century is outlined. Secular trends towards greater height and earlier maturity are reported; the increase in adult height in British men born between 1900 and 1946 averaged about 1.25 cm/decade and in those born between 1946 and 1960 0.6 cm/decade, according to the data of Kuh et al. [Int J Epidemiol 1991;20:1001-1009]. Social class differences in height persist in the UK, amounting to almost 2 cm between the well off and the unskilled. The average height of subgroups of most populations serves well as a proxy for their health status and relates to their mortality rate.

Adult↗
PubMed1991

Effects of growth hormone on neonatal growth in nursing rhesus monkeys.

The effects of recombinant human GH treatment of either nursing mothers or their infants on neonatal growth in rhesus monkeys was determined. Growth rates of infants treated daily from birth with GH (INFGH; n = 9; 100 micrograms/kg, sc) were compared to those of infants given saline (INFc; n = 10), infants whose mothers received saline from the second trimester of pregnancy through 7 weeks postpartum (CON; n = 9), infants of mothers who received GH during pregnancy only from the second trimester to parturition (PRG; n = 8), infants of mothers who received GH during lactation only from parturition through 7 weeks postpartum (LAC; n = 9), and infants of mothers who received GH during the second trimester of pregnancy through 7 weeks postpartum (PRG/LAC; n = 8). Mothers receiving GH were given 250 micrograms/kg, sc, Monday, Wednesday, and Friday. Infants were allowed to nurse ad libitum. Although infant birth weights were similar among the six groups, body weights at 7 weeks of age were significantly greater in PRG/LAC infants (0.77 +/- 0.03 kg) compared to those in CON (0.66 +/- 0.02 kg), INFc (0.62 +/- 0.03 kg), LAC (0.62 +/- 0.04 kg), and INFGH infants (0.62 +/- 0.01 kg), with infants of PRG mothers intermediate (0.71 +/- 0.02 kg) between them. By 35 weeks of age, after infants had been weaned by their mothers, body weights were similar among all groups. Serum concentrations of insulin-like growth factor-I (IGF-I) rose significantly in all infants during the study period. Although IGF-I levels did not vary significantly among the treatment groups, average concentrations of IGF-I were significantly related to weight gains. Analyses of milk composition revealed that total protein, lactose, and IGF-I levels were similar among groups, whereas the percentage of fat in the milk was significantly higher in PRG/LAC mothers. Milk protein content was significantly related to weight gain. These data suggest that neonatal body weight gain can be accelerated in nursing infants whose mothers have received GH from at least the second trimester of pregnancy through the lactational interval. Since infants of mothers receiving GH during lactation only were not different from controls, the effect of GH in this treatment paradigm may be mammogenic rather than galactopoietic per se.

Animals↗
PubMed1991

Long-term effects of recombinant human growth hormone treatment on skeletal maturation and growth in female rhesus monkeys with normal pituitary function.

Female rhesus monkeys (n = 5), having normal pituitary function, were treated for 50 months with recombinant human growth hormone (rhGH; 250 micrograms/kg) 3 days/week (Monday, Wednesday and Friday) and rates of growth were compared with a group of age-matched untreated females (n = 6). Treatment was initiated at 20 months of age, approximately 10 months before the expected age of menarche. Long-term treatment with rhGH accelerated bone maturation and increased the velocity of increase in crown-rump length, tibia length and body weight. The period of acceleration occurred coincident with the occurrence of spontaneous puberty. Body measurements remained larger in the treated females until growth ceased. Long-term rhGH treatment increased final adult crown-rump length by some 3%, with a slight increase in tibia length and body weight, without having any untoward effects on reproductive capacity or health. One treated animal exhibited higher estimates of antibodies to rhGH throughout the study period, and this female also had a smaller increment in crown-rump length than the other treated females. These data suggest that long-term treatment of normal-pituitary females with rhGH augments crown-rump growth without any untoward effects of health.

Animals↗
PubMed1989

Effects of growth hormone on the tempo of sexual maturation in female rhesus monkeys.

The signal that initiates and maintains the developmental change in LHRH and, consequently, LH secretion in primates, thus regulating the tempo of puberty, is not known. Given the close association between reproductive development and bone maturation, we examined the hypothesis that GH was involved in developmental increases in LH release, specifically by augmenting the decrease in estradiol (E2) negative feedback inhibition of LH that characterizes late puberty in primates. Recombinant human GH (rhGH; 250 micrograms/kg) was given (sc) three times weekly to immature female rhesus monkeys to determine if developmental increases in basal serum LH would occur at an earlier age, and if menarche and first ovulation also would be advanced. The study groups included intact females receiving rhGH (INT + GH; n = 5), intact control animals (INT; n = 6), ovariectomized females receiving E2 plus rhGH (E2OVX + GH; n = 5), and E2-treated ovariectomized control monkeys (E2OVX; n = 4). The females were studied from 20 months of age until their serum LH levels increased (E2OVX groups) or until the occurrence of first ovulation (intact groups). After 12 months of rhGH treatment, the crown-rump lengths were significantly increased, regardless of ovarian status, an effect maintained in the intact females through 21 months of treatment. The mean age at the time of the initial rise in serum LH was advanced by rhGH treatment in intact females (29.6 +/- 0.4 vs. 31.3 +/- 0.3 months), but not E2OVX females. Subsequent maturational elevations in LH secretion were similar in the E2OVS + GH and E2OVX animals even after an incremental increase in E2. Ages at menarche were similar in the INT + GH and INT groups, whereas first ovulation was significantly advanced in three of five INT + GH females (31.5 +/- 0.7 months) compared to that in INT females (43.5 +/- 0.3 months). The remaining INT + GH females ovulated at an age (42.4 +/- 0.4 months) similar to that of INT females. Those females that ovulated by 32 months had higher skeletal maturity scores than the later ovulating INT females, with the other INT + GH females being intermediate. Furthermore, rhGH resulted in a significant increase in serum E2 levels within 12 h of injection, which remained elevated through 24 h. This effect of rhGH on ovarian E2 secretion did not occur until females had shown elevations in basal serum LH.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed1988

[Body height in children with growth hormone deficiency: results following 5-l5 years of treatment].

The final results of long-term continuous treatment with human GH in patients with growth hormone deficiency (GHD) are described. Untreated patients with isolated idiopathic GHD average about -6 SD height at maturity; our patients averaged about -2 SD. The statistics appear to show that what is important is starting treatment before the child has fallen much below the normal centiles for height and this usually means before age two or three in idiopathic cases. Ascertainment through an effective system of primary care is more important than an elaboration treatment schedules.

Adolescent↗
PubMed1988

Effects of a natural versus artificial environment on the tempo of maturation in female rhesus monkeys.

To identify factors that regulate the tempo of growth and puberty, the present study examined how the environment influenced the timing of menarche and first ovulation in rhesus monkeys and how these events were related to differential rates of growth. Spring-born females were raised from 12 months of age under natural outdoor conditions (OH; n = 6) or indoors (IH; n = 9) under a controlled photoperiod (12h of light, 12h of darkness) and temperature (20-23 C). Ages at the initial increases in serum bioactive LH levels (27.7 +/- 0.7 vs. 31.4 +/- 1.0 months), menarche (26.0 +/- 0.7 vs. 32.5 +/- 0.9 months), and first ovulation (33.9 +/- 1.4 vs. 43.5 +/- 0.3 months) were significantly advanced in IH compared to OH females. First ovulation for the OH females occurred exclusively in October and November of the fourth year, whereas the distribution of first ovulation of IH females was biomodal, with seven of nine occurring in November or December at 31.8 +/- 0.5 months, and two of nine ovulating in September or October at 41.2 +/- 0.5 months. Serum levels of PRL varied seasonally in OH females throughout development, with peaks in July and nadirs in October. A similar rhythm was observed for IH females during the first 12 months of indoor housing, after which point the period decreased from 11.9 +/- 0.5 to 9.3 +/- 0.6 months. Overall increments in body weight did not differ between groups. An acceleration of growth in both crown-rump and tibial lengths occurred just before menarche in both groups, and this occurred at about 26 months for IH and about 32 months for OH females. Skeletal maturity was significantly advanced at 27 months in IH females and at every chronological age thereafter. Serum concentrations of somatomedin-C and GH paralleled group differences in bone maturation. Both hormones were significantly elevated by 16-18 months of age in IH animals compared to OH females and remained so until 34-36 months of age. Although a distinct seasonal rhythm in both GH and somatomedin-C was evident in OH animals, no such pattern was observed in IH females. These data suggest that exposure to an outdoor environment moderates the tempo of both sexual and skeletal maturation. The acceleration in reproductive development in animals exposed to a constant environment was associated with an acceleration in bone maturation, suggesting that common factors may be responsible for the initiation of both events.

Aging↗
PubMed1987

Issues and advances in adolescent growth and development.

The differences between individuals in tempo of growth, leading to early or late appearance of puberty, are of great importance at adolescence. Late developers, and particularly those who are genetically small as well as late, often suffer acutely and may keep scars of their suffering for years afterward. These individuals need sympathetic support and counseling, which can only be forthcoming from someone who understands thoroughly the auxology of adolescence and is able to tell the adolescent precisely and correctly what will happen in the next six months, one year, and two years. Educating the counselors, and educating the children before they enter adolescence, is a task of importance and immediacy. The physiologic mechanism of tempo is entirely unknown at present, and the major job of research is to remove this ignorance. Close collaboration is needed with pediatric endocrinologists and endocrinologists working with nonhuman primates. A prime need here is for the building of further auxologic and endocrinologic tools and the development of testable models of growth regulation.

Adolescent↗