Relationship between urinary hydroxyproline and growth

Development of a two-dimensional LC-MS/MS system for the determination of proline and 4-hydroxyproline enantiomers in biological and food samples

A two-dimensional LC-MS/MS system has been developed for the enantioselective determination of proline (Pro), cis-4-hydroxyproline (cis-4-Hyp) and trans-4-hydroxyproline (trans-4-Hyp) in a variety of biological samples. The amino acids were pre-column derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), and the NBD-derivatives were separated by a reversed-phase column (Singularity RP18) as their D plus L mixtures in the first dimension. The collected target fractions were then introduced into the second dimension where the enantiomers were separated by a Pirkle-type enantioselective column (Singularity CSP-001S) and determined by a tandem mass spectrometer (Triple Quad™ 5500). The method was validated by the standard amino acids and also by human plasma, and sufficient results were obtained for the calibration, precision and accuracy. The method was applied to human plasma and urine, bivalve tissues and fermented food/beverages. D-Pro was widely found in the human physiological fluids, bivalves and several fermented products. Although trans-4-D-Hyp was not found in all the tested samples, cis-4-D-Hyp was present in human urine and tissues of the ark shell, and further studies focusing on the origin and physiological significance of these D-enantiomers are expected.

Is it really necessary to delay intranasal steroid treatment after FESS? An animal study

OBJECTIVES

The aim of this study is to investigate the effect of early intranasal steroid administration on wound healing after sinus surgery.

STUDY DESIGN

Randomized, placebo-controlled, blinded animal study.

SETTING

Animal laboratory.

SUBJECTS AND METHODS

Forty-two male New Zealand rabbits underwent bilateral 3-mm punch resection of the concha nasalis ventralis. The animals were divided into 3 groups: saline, late steroid, and early steroid. The saline group received saline drops, the late steroid group received saline drops for 7 days followed by intranasal mometasone furoate 50 µg/nostril/d, and the early steroid group received intranasal mometasone furoate (same dose) starting on postoperative day 1. The animals were sacrificed on postoperative days 10 and 21. Left nasal specimens were examined histopathologically with hematoxylin-eosin and matrix metalloproteinase-9 (MMP-9) stains. Right nasal specimens were examined with high-performance liquid chromatography, and hydroxyproline levels were measured as mg/g in wet tissue.

RESULTS

Late steroid and early steroid groups were similar with regard to MMP-9 staining on days 10 and 21. On day 10, the early steroid group revealed significantly intense MMP-9 staining when compared with the saline group, and the late steroid and early steroid groups revealed significant fibrosis when compared with the saline group. Hydroxyproline levels were similar in all groups on day 10. The early steroid group revealed significantly higher hydroxyproline levels when compared with the late steroid group on day 21.

CONCLUSION

Our findings showed that early intranasal steroid administration after sinus surgery in an animal model has no detrimental effects with regard to wound-healing parameters.

Collagen Markers Deoxypyridinoline and Hydroxylysine Glycosides: Pediatric Reference Data and Use for Growth Prediction in Growth Hormone-deficient Children

Background: In children and adolescents, markers of bone and collagen metabolism reflect the dynamics of skeletal growth and development. The aim of this study was to assess the relationship of the urinary collagen markers deoxypyridinoline (DPD) and hydroxylysine (Hyl) and its glycosides [galactosyl-Hyl (Gal-Hyl) and glucosyl-Gal-Hyl] with growth.

Methods: Urine samples from 240 apparently healthy children and adolescents (6–19 years; 124 girls) and from 51 prepubertal children with growth hormone (GH) deficiency (3–14 years; 14 girls) were analyzed. Urinary Hyl and its glycosides were quantified by HPLC, and DPD was assessed by chemiluminescence assay. Urinary concentrations of all markers were related to urinary creatinine.

Results: Multiple regression analysis revealed that only age and height velocity were independently associated with these markers in healthy children. In GH-deficient patients, the urinary excretion of both analytes after 4 weeks of GH therapy correlated significantly with the height increase during the first treatment year (r = 0.79 for Gal-Hyl; r = 0.70 for DPD; P <0.001 each). In a multivariate linear regression model using Gal-Hyl concentrations at 4 weeks, baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 80% of the variability in height gain during the first treatment year. A model using DPD concentrations at 4 weeks, in place of Gal-Hyl concentrations, as well as baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 83% of the variability.

Conclusions: These urinary bone and collagen markers give some early indication of growth response, but the prediction of an individual marker is too imprecise to serve as a basis for clinical decisions. Markers of bone and collagen metabolism might be more useful as components of multivariate growth prediction models.

METABOLISM OF COLLAGEN IN MAMMALIAN TISSUES

The amino acid composition of collagen is described and the status of knowledge about the synthesis of its unique amino acids, hydroxyproline and hydroxylysine, presented. This is followed by a schematic overview of collagen metabolism. Scurvy and lathyrism, the only two abnormalities of collagen metabolism which can now be reasonably elucidated at a molecular level, are then discussed in some detail. The paper concludes by stressing the importance of recognizing the role of histoarchitecture and of interactions of collagen with other compounds when studying collagen or its metabolism in the whole animal.

Biochemical markers of bone turnover in girls during puberty

OBJECTIVE

Bone turnover and the rate of bone growth increase dramatically during puberty. A number of new assays for the estimation of bone resorption and formation rates have been developed over recent years, and puberty acts as a convenient model for evaluation of these measurements. The aim of this study was to explore the interrelationships between pubertal development, biochemical markers of bone turnover, insulin-like growth factor I and oestradiol in healthy pubertal girls.

SUBJECTS

Ninety-one healthy girls (ages 11.6-15.5 years) were studied. All subjects were apparently healthy, and were not taking medications known to influence calcium homeostasis. Breast examination was performed to assess pubertal stage according to Tanner. The adult reference range for biochemical markers of bone turnover was obtained from concurrent studies on 42 healthy premenopausal women ranging in age between 20 and 45 years.

DESIGN AND MEASUREMENTS

Blood samples were obtained from subjects between 0800 and 1000 h. Urine samples were collected between 1330 and 1600 h. We measured total and bone specific alkaline phosphatase, osteocalcin, and type I procollagen carboxyterminal propeptide as markers of bone formation. Tartrate resistant acid phosphatase, carboxyterminal pyridinoline cross-linked telopeptide, creatinine corrected urinary deoxypyridinoline, immunoreactive urinary pyridinolines, and urinary galactosyl hydroxylysine were measured as markers of bone resorption.

RESULTS

Bone turnover as reflected by each of the markers was maximal in mid puberty (breast Tanner stages II and III) and decreased towards adult levels in late puberty (P < 0.001). However, the magnitude of the mid-pubertal increase differed between markers. In particular, the pubertal increase in levels of bone specific alkaline phosphatase, osteocalcin and urinary deoxypyridinoline were higher than the increase shown by the other markers. All markers were significantly lower after the menarche. Circulating insulin-like growth factor I and insulin like growth factor binding protein-3 were not important determinants of pubertal changes in bone turnover. In contrast, there was a significant negative correlation between oestradiol and all markers of bone formation and resorption during puberty.

CONCLUSIONS

The greater pubertal increase in levels of bone specific alkaline phosphatase, osteocalcin and urinary deoxypyridinoline suggests that these markers may be relatively more sensitive as indicators of skeletal health during puberty. The differences between markers may reflect differences in the bone specificity of the analytes, or differing mechanisms of production and clearance. The negative correlation between oestradiol and markers of bone resorption and formation suggests that this hormone may be responsible for the reduction in bone turnover in late puberty.

Growth hormone treatment in Turner's syndrome: short and long-term effects on metabolic parameters

OBJECTIVE

The effect of GH administration on various metabolic parameters and on growth and bone age development was studied in patients with Turner's syndrome.

DESIGN

Patients were treated with daily s.c. GH (20 IU/m2/week) and ethinyloestradiol p.o. (100 ng/kg/day) during the first year and with additional oxandrolone (0.125 mg/kg/day) during the second year. The responses of free fatty acids (FFA), urinary excretion of hydroxyproline (HP) and IGF-I were evaluated after short-term GH application. Glucose tolerance was investigated before any therapy, during treatment with GH and oestradiol and after adding oxandrolone, respectively. The course of growth, bone age and IGF-I levels was followed throughout the study.

PATIENTS

Eleven patients with Turner's syndrome aged 12.6 +/- 1.9 years (mean +/- SD) were included.

RESULTS

Free fatty acids increased significantly 4 hours after one s.c. injection of GH (0.7 +/- 0.2-1.1 +/- 0.3 mmol/l; mean +/- SD). Mean urinary hydroxyproline excretion remained unchanged after 6 weeks of GH therapy (337 +/- 206-299 +/- 145 mumol/m2/24 h), but there was a significant negative correlation between individual hydroxyproline values and the peak serum GH followed stimulation. IGF-I was in the prepubertal range and increased significantly after 3 days of GH injection (30.0 +/- 10.0-42.5 +/- 10.0 nmol/l). Growth velocity (in Turner's syndrome related SD) increased from 0.0 +/- 0.3 SD before treatment to 0.9 +/- 0.8 SD after the first year and to 3.4 +/- 1.3 SD during the second year of treatment. There was no undue acceleration of bone age. During long-term treatment, IGF-I increased significantly only when oxandrolone was added. Two patients had impaired glucose tolerance prior to GH therapy and three additional children developed impaired or abnormal glucose tolerance after GH therapy. Insulin concentrations increased significantly only after introduction of oxandrolone.

CONCLUSIONS

Patients with Turner's syndrome who had lower basal IGF-I levels had significantly higher responses of IGF-I, free fatty acids and hydroxyproline (P less than 0.01 for all parameters) after short-term GH application. The data indicate adequate endocrine and metabolic responses in patients with Turner's syndrome which are the basis for growth promoting action. A considerable number of patients had impaired glucose tolerance during GH treatment.

Assessment of systemic effects of inhaled glucocorticosteroids: comparison of the effects of inhaled budesonide and oral prednisolone on adrenal function and markers of bone turnover

The effects of inhaled budesonide (BUD) and oral prednisolone (PRED) on markers of bone turnover and adrenal function were compared in a randomized, double-blind, double-dummy, crossover study. Twelve healthy subjects were treated for one week with 0.8, 1.6 and 3.2 mg/day BUD and 5, 10 and 20 mg/day PRED, the three doses being given in ascending order. Plasma cortisol and adrenal cortical androgens showed a significantly decreasing trend with the increasing doses of both drugs, although PRED caused a significantly greater decrease than BUD. Osteoblast function, reflected by serum osteocalcin and alkaline phosphatase was significantly reduced by PRED, but BUD had a significantly different effect as it affected only osteocalcin. Urinary hydroxyproline/creatinine, a marker of bone resorption, was not changed by either drug. The average potency ratio for equivalent systemic effects was PRED:BUD 3.9:1. During short-term treatment at equivalent anti-asthmatic doses, BUD has significantly less effect on adrenal function and bone turnover than PRED, and it may carry less risk of bone complications during long-term treatment.

Changes with age in the urinary excretion of lysyl- and hydroxylysylpyridinoline, two new markers of bone collagen turnover

Two intermolecular cross-linking amino acids, hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), are promising markers in urine of collagen resorption because their levels in urine should reflect only collagen resorption and, unlike hydroxyproline, should not be influenced by degradation of either newly synthesized collagen molecules or noncollagenous proteins. Changes with age in the urinary excretion of HP and LP were studied in 24 h collections of urine from a group of 22 male and 27 female healthy subjects aged from 2 to 70 years. The pyridinolines were quantitated, utilizing their natural fluorescence, after resolution by reversed-phase HPLC. Levels of both pyridinolines were higher in children than in adults, but in adults no evidence of age or sex variations were observed except in the 20-30 year age group. Mean values of HP/Cr and LP/Cr in 37 adults (21-70 years) were 27.2 +/- 1.9 and 8.8 +/- 0.8 mumols/mol, respectively; in the 12 children (2-15 years) the mean values were 14.4 and 12.4 times higher than the respective adult values. Making certain assumptions, the mean amount of bone resorbed in normal adults was tentatively estimated at 1.9 g per 24 h. The finding that differences between children and adults in these relatively specific markers were greater than with hydroxyproline suggests that hydroxyproline values may considerably underestimate the actual amount of bone turnover occurring in growing children or overestimate the adult turnover rate.

Synthesis and degradation of collagens in skin of healthy and protein-malnourished rats in vivo, studied by 18O2 labelling

To explore the effects of growth retardation, caused by restricted protein intake, on collagen turnover in the whole skin, Sprague-Dawley rats (n = 20) were labelled with 18O2 and fed on either an adequate (18%) or a low (3%) lactalbumin diet. Skin biopsies were obtained at intervals during the following 6 months. Independent groups of animals (n = 186) were used to determine the size of the 0.5 M-acetic acid-soluble and -insoluble collagen pools in the entire skin of healthy and malnourished rats. Collagen was estimated by measurement of hydroxyproline. Soluble-collagen synthesis rates were equivalent to 99 +/- 8 mumol of hydroxyproline/day in healthy animals and 11 +/- 2 mumol/day in malnourished rats. Insoluble-collagen synthesis rates were 32 and 5 mumol of hydroxyproline/day in the healthy and protein-depleted rats respectively. The degradation of soluble collagen amounted to 37 +/- 8 and 6 +/- 2 mumol of hydroxyproline/day in the healthy and malnourished groups respectively. Efflux of collagen from the soluble collagen, defined as the sum of the rate of soluble collagen that is degraded plus that which matures into insoluble collagen, was 70 +/- 8 and 11 +/- 2 mumol of hydroxyproline/day in the healthy and malnourished groups respectively. Insoluble collagen was not degraded in either group. The fraction of soluble collagen leaving the pool that was converted into insoluble collagen was 0.46 in both diet groups. It is concluded that the turnover of soluble collagen is markedly decreased with malnutrition, but degradation and conversion into insoluble collagen account for the same proportions of efflux from the soluble-collagen pool as in rapidly growing rats.

Experiences of Somatonorm in Sweden

About 180 patients in Sweden are currently receiving treatment with somatrem; a majority of them have previously received pituitary hGH. A high incidence of antibody formation was noted in patients without prior pituitary hGH treatment, but growth velocity was not decreased in these patients. Antibodies developed in about 15% of patients previously treated with pituitary hGH. Adverse effects occurred in four patients within 3 weeks of commencing therapy, but were temporary and treatment could be continued.

Serum levels of aminoterminal type III procollagen peptide in normal subjects and hepatic fibrosis

Serum levels of aminoterminal type III procollagen peptide in normal subjects were determined by radioimmunoassay. The levels of the peptide markedly increase in infants and gradually decrease with age in childhood. The peptide increases again in prepubertal children and then decreases through adulthood. These findings suggest that increased levels of the peptide reflect accelerated collagen synthesis in the human body. Comparison of serum levels of the peptide with the degree of hepatic fibrosis revealed that the peptide increased in parallel with the progress of hepatic fibrosis.

Urinary hydroxyproline excretion in male and female chickens

Hydroxyproline was measured in 24-hr urine samples at 60 and 120 days of age in male and female broiler chickens that were prepared by the "anus praeternaturalis" technique. Twenty-four-hour urine output did not differ between females and males (32.82 +/- 1.02 ml and 33.98 +/- .54 ml, average +/- SD, respectively), whereas 24-hr urinary hydroxyproline excretion was greater in females than in males after 60 days of age. Urinary hydroxyproline excretion tended to decrease with age in males and increase with age in females. Because most of the hydroxyproline is probably derived from bone collagen, the results suggest that there are differences between mineral exchange processes in female and male chickens.

Bacterial lipopolysaccharides induce in vitro degradation of cartilage matrix through chondrocyte activation

The present studies demonstrate that bacterial lipopolysaccharides (LPS) induce cartilage matrix degradation in live explants in organ culture. Quintuplicate bovine nasal fibrocartilage explants cultured for 8 d with three different purified LPS preparations derived from Escherichia coli and Salmonella typhosa at concentrations ranging from 1.0 to 25.0 micrograms/ml resulted in matrix proteoglycan depletion of 33.3 +/- 5.8 to 92.5 +/- 2.0% (medium control depletion 17.7 +/- 0.7 to 32.4 +/- 1.4%). Matrix degradation depended on the presence of live chondrocytes because frozen-thawed explants incubated with LPS failed to show any proteoglycan release. Moreover, the addition of Polymyxin B (25 micrograms/ml) to live explants incubated with LPS abolished matrix release, whereas Polymyxin B had no effect on the matrix-degrading activity provided by blood mononuclear cell factors. A highly purified Lipid A preparation induced matrix degradation at a concentration of 0.01 micrograms/ml. Cartilage matrix collagen and proteoglycan depletion also occurred with porcine articular cartilage explants (collagen release: 18.3 +/- 3.5%, medium control: 2.1 +/- 0.5%; proteoglycan release: 79.0 +/- 5.9%, medium control: 28.8 +/- 4.8%). Histochemical analysis of the cultured explants confirmed the results described above. Gel chromatography of the proteoglycans released in culture indicated that LPS induced significant degradation of the high molecular weight chondroitin sulfate-containing aggregates. These findings suggest that bacterial products may induce cartilage damage by direct stimulation of chondrocytes. This pathogenic mechanism may play a role in joint damage in septic arthritis and in arthropathies resulting from the presence of bacterial products derived from the gastrointestinal tract.

Impaired collagen maturity in vitamins B2 and B6 deficiency--probable molecular basis of skin lesions

Solubility of collagen was increased and the proportion of insoluble collagen was reduced in the skin of both riboflavin as well as pyridoxine-deficient rats. Collagen content of the skin, and aldehyde concentration of salt-soluble collagen were also lower in the deficient groups. The alpha:beta subunit ratio of salt-soluble collagen was higher in riboflavin deficiency. In food-restricted weight-matched control groups, similar changes in collagen solubility, but of lesser magnitude were observed. Both food restriction and riboflavin deficiency decreased plasma PLP concentration. Increase in the solubility of collagen, decrease in the aldehyde content of soluble collagen and increase in the alpha:beta subunit ratio of soluble collagen, suggest that the maturation of collagen may be affected in pyridoxine or riboflavin deficiency. These molecular events may be etiologically related to the pathogenesis of the skin lesions in vitamin B2 or B6 deficiency.

Hyperactivity of fibroblasts cultured from psoriatic skin: II. Synthesis of macromolecules

Glycosaminoglycans and protein synthesis were assessed in fibroblasts cultured from the involved (PSA strains) and uninvolved (PSB strains) forearm skin of patients with severe generalized psoriasis and compared with that in fibroblasts from the forearm skin of control subjects of similar ages (NSF strains). Average rates of glycosaminoglycan secretion were 19% (PSA) and 28% higher (PSB) in psoriatic strains. Although these differences were not significant in themselves, the relationship between glycosaminoglycan secretion and fibroblast density (cells/cm2) was significantly different (P = 0.02) for the psoriatic and control groups, with the psoriatic cells secreting appreciably more glycosaminoglycans at higher cell densities. The nature of the glycosaminoglycans produced was the same in psoriatic and normal strains; 90% was recovered in the culture medium and the bulk of this appeared to be hyaluronic acid with only small amounts of sulphated components. Collagen synthesis was 77% higher in PSA and PSB strains (P less than 0.01), while other protein synthesis was increased by 44% (P less than 0.05). These findings confirm that fibroblasts from psoriatic skin are hyperactive in vitro. The data are compatible with the results of studies of psoriatic skin in vivo and suggest that the entire skin is abnormal.

Urinary free amino acids pattern in protein-energy malnourished Sudanese children

The urinary free amino acid pattern in a morning urine sample of Sudanese children suffering from Kwashiorkor and marasmus were determined before and during the course of treatment up to the 2nd week. The urinary amino acid/total urinary N (3.62) was found to be almost constant for Kwashiorkor patients, while the mean for marasmic patients was found to be 27. The concentration of leucine, valine, phenylalanine, methylhistidine, lysine, hydroxylysine and beta-amino-isobutyric acid was elevated in marasmic children, while the concentration of most of these amino acids was at a lower level in Kwashiorkor patients. The significance of these differences was discussed in relation to the biochemical detection of these deficiencies in field nutrition surveys.

Human mononuclear cell factors mediate cartilage matrix degradation through chondrocyte activation

Human blood mononuclear cells (BMC) in short-term culture secrete one or more factors that induce degradation of matrix proteoglycan and collagen in cartilage explants in organ culture. Induction of matrix degradation took place both in nasal septum and articular cartilage explants in the presence of the mononuclear cell supernates. Cartilage degradation in this system was absolutely dependent on the presence of live chondrocytes. Matrix depletion did not occur in dead cartilage explants cultured with active supernates. Supernates obtained from unstimulated BMC showed variable cartilage matrix degrading activity (MDA). BMC stimulated with phytohemagglutinin (PHA) showed increased MDA, which in one dilution experiment was found to be five times higher than that in the unstimulated control supernate. Concanavalin A and pokeweed mitogen were also shown to stimulate release of MDA. Time experiments showed that most of the degrading activity was released by the mononuclear cells during the first day of culture. The cellular origin of MDA was investigated with the aid of partially purified BMC subpopulations. Removal of adherent cells resulted in a decrease of MDA release. Purified T lymphocytes failed to show enhanced MDA release in spite of their ability to mount a virtually intact proliferative response to PHA. Purified adherent cells also failed to show enhanced PHA-dependent MDA release. Nevertheless, restoration of PHA-dependent MDA release took place in reconstituted cell populations containing both T lymphocytes and monocytes. These experiments suggest that MDA may be released by adherent mononuclear cells, presumably monocytes, and that the PHA-dependent increase in MDA release may be mediated by T lymphocytes. Partial characterization of MDA by gel chromatography showed one active fraction corresponding to an apparent molecular weight ranging from 12,000 to 20,000. The fraction was also shown to degrade cartilage matrix only in the presence of live chondrocytes. These results demonstrate that factors released by human BMC mediate degradation of matrix proteoglycan and collagen in intact cartilage explants through chondrocyte activation. This pathogenic mechanism may play a role in in vivo cartilage destruction in chronic inflammatory joint diseases.

Serum somatomedin A and non-dialyzable urinary hydroxyproline in girls with idiopathic scoliosis

Serum somatomedin A was determined by radioreceptor assay in 31 girls with idiopathic scoliosis and 30 controls, with ages ranging from 9.7-16.2 years. In the material as a whole no significant difference could be found between scoliotics and controls. Similarly no differences were found in the girls under 13 years of age. However, in girls older than 13 years the controls had significantly higher somatomedin A levels than the scoliotics. In the second part of the study 26 girls with idiopathic scoliosis and 22 controls were examined with regard to the urinary excretion of non-dialyzable hydroxyproline,. which has been suggested to be correlated with collagen synthesis. The percentage non-dialyzable fraction of the total hydroxyproline was found to be significantly higher in the control girls. The mean age was 12.8 years for both groups. The results suggest a higher growth rate in the controls than in the scoliotics for girls over 12 years. There is, however, no definite evidence as to the function of the somatomedins or of the relationship between non-dialyzable hydroxyproline and growth.

One year's study of growth and total hydroxyproline excretion in scoliotic children

21 children with scoliosis were studied for a year during which time 24-hour urinary total hydroxyproline levels are estimated and anthropometric measurements were made on 4 occasions. The total hydroxyproline levels (using hydroxyproline centiles) and the uncorrected heights of the children were all normal. The sitting heights of the children were below average, but, although the sample was small, the findings indicate that the children's 'uncoiled' height would be greater than average.

Rheumatoid arthritis and growth retardation in children: treatment with human growth hormone

Twenty patients with rheumatoid arthritis or Still's disease associated with growth failure were treated with human growth hormone, 7.5 to 17 U/m2 body surface per week. Five patients did not respond with better growth. In the remainder the mean growth rate increased from 1.9 cm/year (range: 0 to 3.3) to 6.2 cm/year (range: 3.6 to 12) over 5 to 7 months. Twelve patients treated for longer periods increased their mean growth rate from 2.6 cm/year (range: 0.7 to 5.7) to 6.3 cm/year (range: 2.4 to 9.7) and continued to grow during a second year of treatment. Growth velocity decreased in 6 patients when the hGH therapy was discontinued. The causes for this improvement in growth are possibly multifactorial: the growth rate is depressed by the severity of the disease and high-dose glucocorticoid therapy. Increases of growth rate occurred during improvements in the disease, reduction of steroid medication, as a result of therapy with human growth hormone, and because of puberty in some patients. Human growth hormone seemed to improve the underlying condition of four of the patients but had no influence on the disease in the remaining children.

Effect of varying energy and protein intake on nitrogen balance in adults engaged in heavy manual labour

1. The effect of varying energy and protein intake on nitrogen balance in adult men engaged in heavy manual labour was investigated. 2. Low protein and energy levels resulted in negative N balance and urea index (Waterlow, 1963) was decreased. 3. Urinary excretion of hydroxyproline was found to be sensitive to dietary protein level, but not to energy.

Urinary hydroxyproline, creatinine and urea excretion during the growth of five siblings

Urinary excretions of hydroxyproline, creatine and urea in 24 h specimens from 5 siblings have been determined monthly from 1971 to 1976 together with the measurements of body height and body weight. Changes with age in the urinary levels of these substances are in good agreement with those from cross-sectional studies in various age groups of children. Wide fluctuations of excretion levels occurred. The creatinine coefficients did not remain constant even over short periods. Menarche was observed shortly after the peak of hydroxyproline excretion at puberty. The hydroxyproline excretion pattern is similar to that of hydroxyproline index proposed by Whitehead, and it is quite different from that of hydroxyproline ratio.

Total hydroxyproline in urine of 4 to 6 year-old children--an investigation on its relationship to growth and nutrition

We analysed over a period of 30-32 days the daily total hydroxyproline and creatinine excretine in urine from 9 healthy, normally fed 4 to 6 year-old children (2 girls, 7 boys). The average urinary hydroxyproline excretion was 45.6 mg/24 hr, with a coefficient of variation of 25.6%. Urinary hydroxyproline for individual children showed distinct differences from day to day, which were independent of urine volume. There were significant differences between the mean values for urine hydroxyproline in individual children, which were independent of age. The average creatinine in urine was 346/24 hr with a coefficient of variation of 17.7%. The hydroxyproline-index did not define the nutritional state of these normally developed children on a normal diet. Dietary hydroxyproline contributed 7.4% to the total urinary hydroxyproline in our investigation. There was a close correlation between urine hydroxyproline excretion and growth velocity in each child.

Reduction of collagen biosynthesis in blood vessels and other tissues by reserpine and hypophysectomy

Synthesis of collagen in the vasculature and other tissues of normotensive rats is markedly reduced by reserpine. Hypophysectomy produces similar effects. The effects of reserpine on collagen biosynthesis may be mediated through the hypothalamus.

Bound hydroxyproline excretion following gelatin loading in prolidase deficiency

The excretion of peptide-bound hydroxyproline before and after gelatin loading was evaluated in two children with prolidase deficiency, two adult heterozygotes, and normal controls. On a low hydroxyproline diet, the patients with prolidase deficiency excreted 6.9 and 2.4 times more bound hydroxyproline than normal children. The bound hydroxyproline excretion for the heterozygotes was comparable to the adult controls. Children ingested 20 g of gelatin and adults 29 g. In the 24 hr following gelatin loading, the homozygotes excreted 14.4 and 17.3 times more of the ingested load of hydroxyproline than did normal children. This constituted 39% and 47% of the hydroxyproline ingested. Of the hydroxyproline excreted in 24 hr, 58%, and 61.4% was excreted in the first 6 hr. Over the 24 hr period, the normal children excreted 2.7% of the hydroxyproline ingested (97.8% in the first 6 hr). The heterozygotes excreted only slightly more than the adult controls. The normal adults excreted 6.0% of the ingested hydroxyproline (82.8% in the first 6 hr). In prolidase deficiency, large amounts of peptide-bound hydroxyproline can cross the intestinal wall unhydrolyzed. Prolidase appears to have an important role in normal hydrolysis of peptide-bound hydroxyproline.

Serum alkaline phosphatase and urinary hydroxyproline values in children receiving phenobarbital with and without vitamin D

Concentrations of serum alkaline phosphatase and total urinary hydroxyproline were measured in 36 children to study the effect of phenobarbital administration with respect to the development of rickets in patients receiving anticonvulsive medications over prolonged periods of time. Administration of phenobarbital led to the appearance of increased AP and HOP values very early in the course of treatment and without any obvious bone changes suggestive of rickets; a single large oral dose of vitamin D had no appreciable effects in restoring the biochemical derangement. On the other hand, the administration of vitamin D in a daily dose of 4,000 IU for a period of two months hampered the appearance, or restored already existing changes of latent rickets, in children receiving anticonvulsive medication. The results in the present study favor the concept that phenobarbital administration is implicated in the development of rickets. The need for simultaneous daily administration of supplements of vitamin D in subjects receiving anticonvulsive drugs is stressed.

Peripheral resistance to thyroxine: a cause of short stature in a boy without goitre

A euthyroid pubertal boy was investigated for short stature and was found to have an elevated serum thyroxine and delayed bone age. In spite of high thyroxine levels, there were no clinical signs of hyperthyroidism and kinetic studies revealed a normal rate of thyroxine metabolism. Plasma TSH levels were elevated but there was no goitre. Administration of up to 900 mug of thyroxine or 225 mug of triiodothyronine led to minimal changes in urinary hydroxyproline excretion, pulse rate and body weight. These observations indicate that this boy has a target organ insensitivity to thyroid hormones. When compared with other patients with this disorder, the studies further emphasize that this condition may have a variable clinical presentation. In addition, the extent of the target organ defect may not be evident from routine clinical and laboratory observations. The possible molecular basis of the defect is discussed.

Treatment of acromegaly by transsphenoidal hypophysectomy with cryoapplication

The therapeutic effect of transsphenoidal hypophysectomy with cryoapplication has been studied in twenty-nine patients with active acromegaly. The mean follow-up time was 15 months (354 months). A significant improvement of symptoms and signs occurred in all but three patients. The level of plasma immunoreactive growth hormone (IRGH) was reduced in all but two patients and a normal level of plasma IRGH was achieved in sixteen patients. Skin thickness, the level of serum inorganic phosphorus and the urinary excretion of hydroxyproline and calcium were significantly decreased in the great majority of the patients. The operation was not accompanied by any visual complications, but cerebrospinal rhinorrhoea, subsiding spontaneously, developed in two and postoperative meningitis in one patient. Hypothyroidism and adrenocortical deficiency developed in eight, gonadotrophin deficiency in thirteen, and persistent diabetes insipidus in one patient. It is concluded that transsphenoidal hypophysectomy with cryapplication is a safe and effective method for the treatment of acromegalic patients.

Urinary hydroxyproline excretion in early and advanced breast cancer-a sequential study

A sequential study of urinary hydroxyproline was performed in 47 patients with cancer of the breast. The results have shown that hydroxyproline excretion in the urine provides a sensitive index of the early development of secondary deposits in bone from primary breast cancer. Elevation of the urinary excretion of hydroxyproline may predate by several months the radiological demonstration of osseous deposits. Sequential estimations have shown that the elevated urinary hydroxyproline excretion is persistent in patients who subsequently develop deposits in bone.

Serum alkaline phosphatase and rickets in urban schoolchildren

Among 569 schoolchildren (386 boys and 183 girls) aged 14-17 years, 233 had serum alkaline phosphatase values of 30 K.A. units or greater. There was no significant difference in the results in Asian, white, or West Indian children. The mean values were significantly greater in boys than girls and both showed a fall in mean values with increasing age. Radiological rickets occurred in at least 4% of the survey, and was more common in Asians. Low calcium and high hydroxyproline excretion in most of those investigated and the response to vitamin D therapy suggests that most children with alkaline phosphatase levels above 30 K.A. units have rickets.Since the decline of the widespread supplementation of the diet with vitamin D, the demands of the physiological growth spurt for extra vitamin D in adolescents already on a borderline intake may be responsible for the great increase in "biochemical" rickets. Once the growth spurt is over the condition subsides but the results of impaired growth or permanent pelvic deformity will not necessarily be eradicated.