Measurements of total body fat (BF) and fat free mass (FFM) obtained by anthropometry, using the Durnin and Womersley (DW) equations, and by total body dual energy x-ray absorptiometry (DXA) were compared in 8 adults with childhood-onset GH deficiency (GHD) and in 9 healthy subjects. The sensitivity of these two methods in detecting the changes in body composition produced by six months of GH therapy in patients with GHD was also compared. Anthropometric determination of percent BF was calculated from the sum of biceps, triceps, subscapular and suprailiac skinfolds, using the appropriate DW and Siri equations for body density and percent fat estimation. FFM was calculated by subtracting BF from body mass (BM). BF and FFM were also determined by DXA (QDR 1000/W, Hologic Inc). The data obtained from the GHD patients were compared with those recorded in a control group of healthy males, matched for sex, age and physical activity. Body composition obtained by anthropometry: before GH treatment, significant differences existed between patients and controls in terms of BM (mean +/- SD: 45.8 +/- 10.0 vs 71.7 +/- 6.6 kg), percent BF (21.0 +/- 3.2 vs 17.1 +/- 3.7%) and FFM (36.0 +/- 6.5 vs 59.3 +/- 3.7 kg), while body mass index (BMI, kg/m2) values were similar in the two groups. Six months of GH therapy did not change BM and BMI, but caused a significant reduction of percent BF (from 21.0 +/- 3.2 to 18.6 +/- 4.0%) and a rise of FFM (from 36.0 +/- 6.5 to 38.0 +/- 6.7 kg). After treatment, no significant differences were found between percent BF values of patients and controls. Body composition obtained by DXA: BF (22.0 +/- 3.9%) and FFM (37.2 +/- 8.0 kg) of patients significantly differed from those of controls (16.8 +/- 3.7% and 59.8 +/- 3.7 kg) before treatment; after GH treatment, percent BF values (17.7 +/- 4.9%) of patients were similar to those of controls. Anthropometry vs DXA: high correlation (p < 0.001-0.0001, R2 = 0.784-0.988) was found between the percent BF and FFM determined by anthropometry and by DXA for both patients, before and after treatment, and controls. It is noteworthy that, for both BF and FFM, most values were evenly distributed along the identity line, showing no systematic overestimation or underestimation by anthropometry. The relation between DXA and anthropometry was maintained even after GH treatment. These results indicate that body fat and FFM assessment by anthropometry are comparable to those by DXA. GH-induced changes in body composition in hypopituitary adults are detected with the same level of accuracy by the two techniques. The reliability, practicality and low cost of anthropometry favour its use for the assessment of body composition even in GHD patients.

Absorptiometry, Photon↗

PubMedDate not supplied

The social outcome of adults with constitutional growth delay.

It is well established that children with extreme short stature, secondary to GH deficiency (GHD) or achondroplasia, face a disability that may affect their adult psychosocial outcome, while contrasting data are reported for short normal children. In our hands, adults with GHD have shown an unsatisfactory psychosocial adjustment due to the low adult height and hypothetically to the persistent GHD. This study has been carried out to evaluate the influence of growth in height on the social outcome in 45 adults with constitutional growth delay (CGD). Interviews with subjects and parents were used for assessment. Data obtained were compared with those found in an age, sex and social matched control group of adults with normal height. Some issues were also compared with the data we previously found in adults with GHD. Present mean age of the patients is 24 +/- 2 yr. A high percentage (32.8%) of unemployment or underemployment (part-time work) was found. Four patients (8.8%) were married, while 84.4% lived with their parents or relatives, confirming the notion of prolonged economic dependency on the family. The patients preferred single sporting activities, avoiding team work. Surprisingly, scholastic achievement was in general similar to that observed in controls. Similar findings have been previously observed in patients with GHD. Since no defect in GH secretion has been documented in CGD, the presence of a negative psychosocial outcome more probably seems to be due to the final unsatisfactory height rather than to a GH defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Bovine beta-lactoglobulin H: isolation by preparative isoelectric focusing in immobilized pH gradients and preliminary characterization.

In spite of the fact that beta-lactoglobulin (beta-lg) was first discovered in bovine milk more than fifty years ago, and that it represents the main whey protein component in all the milks in which it has been found, its biological role and genetic evolution still remain rather uncertain. From comparative studies of the primary and tertiary structures of beta-lg and of other proteins of a similar size, the existence of a new superfamily of proteins with the function of transporter of hydrophobic molecules has been conjectured. The elucidation of the structure of beta-lg either from different species or from different genetic variants of the same species should give useful information on the evolution and function of this protein family. With this aim in mind we have now undertaken the isolation and characterization of a recently discovered, new genetic variant of bovine beta-lg. A two-step purification procedure involving preparative HPLC gel filtration and preparative IEF-IPG has been successfully carried out; it affords a good recovery of the new beta-lg in highly purified form.

Amino Acids↗

PubMedDate not supplied

Direct identification and characterization of llama (Lama glama L.) whey proteins by microsequencing after western blotting.

Amino acid sequence determination is the most reliable and powerful tool to identify a protein or to classify a new one by comparison of its primary structure with already known sequences. A rapid and simple purification procedure is an essential pre-requisite for routine sequence determination. Structural characterization of llama whey proteins was undertaken for evolutionary as well as economic purposes. N-terminal sequence analyses directly on an immobilon polyvinylidene difluoride (PVDF) membrane, following Western blotting of both native and SDS-denatured llama whey proteins after polyacrylamide gel electrophoresis, revealed three different forms of glycosylated alpha-lactalbumin, and a protein with a high degree of homology with a camel whey protein of unknown function. Furthermore, by immunoblotting techniques, the electrophoretic band corresponding to serum albumin was identified.

Amino Acid Sequence↗

PubMedDate not supplied

A rapid microbore HPLC method for determination of primary structure of beta-lactoglobulin genetic variants.

A rapid method for determination of the primary structures for beta-lactoglobulin (beta-LG) genetic variants is described. This included rapid microbore HPLC, amino acid analyses, and wherever necessary, direct peptide sequencing. Two novel variants of beta-LG have been identified, bovine beta-LG W and ovine beta-LG C. The proteins were oxidized, digested with trypsin and separated using RP-HPLC. All peptides were recovered in a single run. Peptides with amino acid exchanges were identified by retention time and subjected to amino acid and sequence analyses. Ovine beta-LG C differs from the ovine beta-LG A variant by a single amino acid exchange at position 148 where Arg is replaced by Gln. Bovine beta-LG W differs from bovine beta-LG B by having Leu at position 56 instead of Ile. The method described here is reliable and can be used for mapping of 20-1000 pmol of material.

Amino Acid Sequence↗