Alternative processing of the RNA transcribed from the calcitonin gene appears to result in the production of a messenger RNA in neural tissue distinct from that in thyroidal 'C' cells The thyroid mRNA encodes a precursor to the hormone calcitonin whereas that in neural tissues generates a novel neuropeptide, referred to as calcitonin gene-related peptide (CGRP) The distribution of CGRP-producing cells and pathways in the brain and other tissues suggests functions for the peptide in nociception, ingestive behaviour and modulation of the autonomic and endocrine systems The approach described here permits the application of recombinant DNA technology to analyses of complex neurobiological systems in the absence of prior structural or biological information

Production of a novel neuropeptide encoded by the calcitonin gene via tissue-specific RNA processing

High serum procalcitonin concentrations in patients with sepsis and infection.

结节病易误诊,据王洪武等~([1])收集国内18篇关于此病误诊的文献,误诊率高达63.2%,当然有误诊就会有误治,如孙永昌等~([2])报道26例结节病在影像学检查诊断的第一印象中拟诊结核5例,其中就有2例完成规范的抗结核治疗,为此应引起临床对本病诊治的重视。

Sarcoidosis

Changes of bone turnover with aging are responsible for bone loss and play a major role in osteoporosis Although an increase of bone turnover has been documented at the time of menopause, the subsequent abnormalities of bone resorption and formation and their potential role in determining bone mass in the elderly have not been investigated To address this issue, we have measured a battery of new sensitive and specific markers of bone turnover in a population-based study of 653 healthy women analyzed cross-sectionally, including 432 women postmenopausal from 1 to 40 years, and the data were correlated with bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) at different skeletal sites Bone formation was assessed by serum osteocalcin (OC), serum bone-specific alkaline phosphatase (B-ALP), serum C-propeptide of type I collagen (PICP), and bone resorption by the urinary excretion of two pyridinoline cross-linked peptides (NTX and CTX) Bone turnover increased in perimenopausal women with both irregular menses and elevated serum follicle stimulating hormone (FSH) Menopause induced a 37-52% and 79-97% increase in the bone formation and bone resorption marker levels, respectively (p < 00001 except for PICP) In postmenopausal women, bone formation markers did not decrease with age When resorption markers were corrected by whole body bone mineral content (BMC), the fraction of bone resorbed per day was not correlated with age in postmenopausal women and remained elevated for up to 40 years after menopause In premenopausal women, the bone turnover rate accounted for only 0-10% of the variation in whole body BMC, total hip, distal radius, and lumbar spine BMD With increasing time after menopause, the importance of the bone turnover rate as a determinant of bone mass increased at all sites and accounted for up to 52% of the BMD variance in elderly women Thus, in women 20 years or more postmenopause, bone turnover was higher in those in the lowest quartile than in those in the highest quartile of BMD In elderly women, 20 years since menopause and over, but not in younger ones, serum PTH was negatively correlated with serum 25-hydroxyvitamin D (r = -022, p < 005) and explained only 5-8% of the bone turnover variance (p < 001-0001) These data indicate that the overall rates of both bone formation and bone resorption remain high in elderly women The rate of bone turnover appears to play an increasing role as a determinant of bone mass with increasing time since menopause with a high bone turnover rate being associated with a low bone mass Thus assessing bone marker levels may be useful in the evaluation of osteoporosis risk In elderly women, secondary hyperparathyroidism caused in part by reduced serum 25-hydroxyvitamin D appears to be a marginal determinant of an increased bone turnover rate

Increased bone turnover in late postmenopausal women is a major determinant of osteoporosis

THIS REVIEW will deal with the biosynthesis of many of the members of the ACTH/lipotropin (LPH) family of peptides (Fig. 1). Peptides in this family fall into two groups: peptides related to ACTH include α-melanotropin (αMSH) and corticotropin-like intermediate lobe peptide (CLIP); peptides related to βLPH include γLPH, βMSH, and β-endorphin. In several species ACTH and βLPH each contain an identical heptapeptide segment located in the region of the molecule that is responsible for melanotropic bioactivity (1, 2). In this review we have taken a somewhat historical approach, and will therefore begin with a discussion of the biosynthesis of ACTH and the characterization of biosynthetic precursors to ACTH. When this work began, βLPH, γLPH, and βMSH were well-characterized pituitary peptides, but the opioid peptides (and β-endorphin in particular) had not yet been identified (3–5). Studies on the biosynthesis of ACTH were heavily influenced by prior work defining the biosynthetic pathways for insulin and para...

Structure and Biosynthesis of Pro-Adrenocorticotropin/Endorphin and Related Peptides*

gamma-Carboxyglutamic acid-containing protein of bone (BGP) is an abundant noncollagenous protein of mammalian bone. BGP has a molecular weight of 5,800 and contains three residues of the vitamin K-dependent amino acid, gamma-carboxyglutamic acid. We have applied a radioimmunoassay based on calf BGP for the measurement of the protein in the plasma of 109 normal humans and 112 patients with various bone diseases. BGP in human plasma was demonstrated to be indistinguishable from calf BGP by assay dilution studies and gel permeation chromatography. The mean (+/- SE) concentration of BGP in normal subjects was 6.78 (+/- 0.20) ng/ml, 7.89 (+/- 0.32) for males and 4.85 (+/- 0.35) for females. Plasma BGP was increased in patients with Paget's disease of bone, bone metastases, primary hyperparathyroidism, renal osteodystrophy, and osteopenia. Plasma BGP did correlate with plasma alkaline phosphatase (AP) in some instances, but there were dissociations between the two. It was additionally observed that patients with liver disease had normal plasma BGP despite increased plasma AP, a reflection of the lack of specificity of AP measurements for bone disease. Our studies indicate that the radioimmunoassay of plasma BGP can be a useful and specific procedure for evaluating the patient with bone disease.

/pdf/new-biochemical-marker-for-bone-metabolism-measurement-by-29c6370kci.pdf

New biochemical marker for bone metabolism. Measurement by radioimmunoassay of bone GLA protein in the plasma of normal subjects and patients with bone disease.

THE function of many endocrine glands is influenced by age and sex.1 Only recently have these two factors been shown to influence the secretion of the calcemic peptide hormones parathyroid hormone and calcitonin.2 3 4 To evaluate the effects of age and sex on plasma calcitonin in human beings, we expanded our preliminary studies5 and measured plasma levels of the hormone by radioimmunoassay in 137 normal subjects of both sexes. We found that irrespective of age, the increase in calcitonin in response to calcium infusion was greater in men than in women, but that basal levels of calcitonin and the response to . . .

Influence of Age and Sex on Plasma Calcitonin in Human Beings

We evaluated the pattern of osteoporosis after spinal cord injury, determined the time-frame of the changes, and elucidated the relationship among parathyroid hormone levels, biochemical markers of bone formation, and the pattern of bone mass loss. We included 176 subjects with spinal cord injury and 62 subjects without spinal cord injury as controls in the study. Bone mineral density of the spine and the proximal femur was measured. The participants' age, level of injury, and length of time since injury were compared with the nonspinal cord-injured controls and with each other. Serum levels of calcium, calcitonin, biochemical markers of bone formation, and parathyroid hormone were determined. Our results revealed that bone mineral density of the proximal femur declined and reached fracture threshold at one to five years after injury. The decline was detected at 12 months after injury in all age groups. Spinal bone mineral density neither declined significantly nor reached fracture threshold. Parathyroid hormone levels declined before the end of the first year postinjury and increased at one to nine years postinjury in the 20- to 39-year age group. The increase correlated with the initial decline of bone mineral density of the proximal femur. Our studies in spinal cord-injured subjects revealed a pattern of osteoporosis similar to age and parathyroid dysfunction-related osteoporosis. No other correlation was detected between indexes of bone metabolism and bone mineral density measurements.

Bone Mineral Density And Indexes Of Bone Metabolism In Spinal Cord Injury

Bone Gla protein (BGP) was measured in the plasma by radioimmunoassay (RIA) during treatment of 59 patients with bone diseases including Paget's disease (N=9), primary hyperparathyroidism (N=25), chronic renal failure (N=20), and cancer involving bone (N=5). Plasma BGP was increased above normal in all patients. BGP decreased in the patients with Paget's disease following the acute and chronic administration of salmon calcitonin. Plasma BGP was higher in women then in men with primary hyperparathyroidism. Following parathyroidectomy, BGP decreased in both sexes but the decrease was significant in women only. Plasma BGP was increased in patients with renal osteodystrophy and did not change after hemodialysis. In the patients with bone cancer, plasma BGP decreased during treatment of the attendant hypercalcemia with salmon calcitonin. Although plasma BGP and serum alkaline phosphatase (AP) levels were generally correlated in these studies, there were examples of dissociation between the two. The measurement of plasma BGP appears to provide a specific index of bone metabolism that may in some circumstances be more sensitive than serum alkaline phosphatase measurement. However, further studies are necessary to establish the clinical value of plasma BGP measurement by RIA in the management of patients with bone diseases.

Changes in plasma bone GLA protein during treatment of bone disease.

A sensitive RIA for human calcitonin has been developed which can detect 1-2 pg hormone. This procedure permits the measurement of the low concentrations of calcitonin in the unextracted plasma of normal human subjects. In 55 normal adults, mean plasma calcitonin was 24 pg/ml with an SD of ±18 pg/ml, an SE of ±2 pg/ml, and a range of < 10–75 pg/ml. There were no discernible age or sex differences in basal hormone concentration. Infusions of calcium, pentagastrin, and glucagon stimulated plasma calcitonin, whereas food and oral calcium did not. The stimulatory effect of pentagastrin was greater in males than in females. These data demonstrate that the low concentration of calcitonin in humans can be stimulated by several secretagogues and suggest that females may have decreased calcitonin reserve.

J. G. Parthemore

Papers

New biochemical marker for bone metabolism. Measurement by radioimmunoassay of bone GLA protein in the plasma of normal subjects and patients with bone disease.

Influence of Age and Sex on Plasma Calcitonin in Human Beings

Bone Mineral Density And Indexes Of Bone Metabolism In Spinal Cord Injury

Changes in plasma bone GLA protein during treatment of bone disease.

Calcitonin secretion in normal human subjects.