C reactive protein in pancreatic cancer and chronic pancreatitis

Serum C reactive protein was determined in 30 control subjects, 32 patients with pancreatic cancer, 28 with chronic pancreatitis and 23 with extra-pancreatic diseases of the upper gastrointestinal tract. The aim was to ascertain possible alterations of this index in chronic pancreatic disease and to speculate on some influencing factors. Higher C reactive protein levels were found in pancreatic cancer as compared to controls. Pancreatic cancer patients with systemic metastases had higher levels of this index compared to those with non-metastatic disease. Raised concentrations of C reactive protein were detected in 7/28 subjects with chronic pancreatitis. In this group these higher levels were found in patients in a relapsing phase of the disease; no association was observed with pancreatic pseudocysts. Among all subjects a correlation was found, between C reactive protein and age; patients with abnormal fasting blood glucose levels or increased white blood cell count had higher levels of this protein as compared to the remaining patients. We may conclude that C reactive protein increases in pancreatic cancer, specially in relation to tumour extent; in chronic pancreatitis it reflects the inflammatory status of the gland. While acting in the context of the acute phase response, this test may provide an adjunct in evaluating patients with a chronic pancreatic disease.     

Concentration of zinc and zinc-copper superoxide dismutase activity in red blood cells in normals and children with cancer

Zinc concentrations and Cu, Zn superoxide dismutase activity in erythrocytes were investigated in 138 healthy children and in 35 children with cancer. The mean zinc concentration in the erythrocytes of healthy children was found to be age-dependent. In the youngest group (children up to 1 year of age) the zinc concentration in erythrocytes is 18.8 +/- 3.4 micrograms/g Hb (5.89 +/- 1.23 mg/l packed cells), which is significantly lower than in other age groups. A strong logarithmic correlation (r = 0.327, p less than 0.0001 and r = 0.436, p less than 0.00001) was found between age and zinc concentration in erythrocytes, expressed as microgram/g Hb and as mg/l packed red cells, respectively. Cancer children were divided into two groups (neuro- and nephroblastoma). In the group of children with neuroblastoma no statistical differences in zinc concentration or enzyme activity were observed. In the patients with nephroblastoma, significantly higher zinc concentrations (p less than 0.05) were observed in erythrocytes. The changes of zinc concentration are accompanied by significant (p less than 0.02) decreases of enzyme activity. In this group of cancer children, statistically significant differences were observed in the zinc concentrations in erythrocytes (microgram/g Hb) between the second and the third stages of the disease. No correlation was observed between the concentration of zinc and enzyme activity in healthy children or in cancer children.     

Elevated fasting cholecystokinin levels in pancreatic exocrine impairment: evidence to support feedback regulation

Previous studies have suggested that intraduodenal protease suppression of pancreatic exocrine secretion may be mediated through cholecystokinin (CCK) release. Our study compares basal plasma immunoreactive CCK concentrations in normal human subjects with those obtained in patients with chronic pancreatitis. Fasting plasma samples were collected from 18 normal subjects and from 18 patients with chronic pancreatitis. Eight patients had mild to moderate pancreatic exocrine impairment, and 10 had severe exocrine insufficiency. Venous plasma immunoreactive CCK concentrations were measured with two distinct peptide region-specific antibodies. Basal plasma CCK concentration in controls was 14.3 +/- 1.3 fmol/ml (mean +/- SEM), a value significantly less than that obtained in all patients with chronic pancreatitis, 30.1 +/- 4.0 fmol/ml (p less than 0.001). Patients with mild to moderate impairment had a fasting plasma CCK concentration of 32.8 +/- 7.9 fmol/ml (vs. control p less than 0.01), and those with severe disease 27.9 +/- 3.6 fmol/ml (vs. control p less than 0.001). In five patients with mild to moderate impairment of exocrine function and pancreatic extract-responsive abdominal pain, there was a 39 +/- 11% decrease in basal CCK levels during extract therapy (p less than 0.05). Results of this study indicate that pancreatic exocrine impairment is associated with elevated basal CCK levels, which may reflect a failure to provide feedback downmodulation of CCK release.     

Diagnostic utility of a new monoclonal antibody pancreatic isoamylase assay in chronic pancreatic diseases

In order to evaluate the efficacy of a monoclonal pancreatic (P) isoamylase assay in the diagnosis of chronic pancreatic disease and to compare the behavior of this test with that of amylase and elastase 1, these three enzymes were measured in the sera of 39 healthy controls, 28 patients with pancreatic cancer, 50 with chronic pancreatitis and 60 with extra-pancreatic diseases. In patients with chronic relapsing pancreatitis, increased P-isoamylase and elastase 1 values were found in similar percentages (about 70%), whereas the percentage for elevated amylase values was lower (52%). Elastase 1 was increased in 52% of patients with pancreatic cancer, while the other two enzymes were only occasionally elevated. The levels for all three enzymes were abnormal in some patients with extra-pancreatic diseases. It may be concluded that this assay for P-isoamylase determination is sufficiently sensitive and reliable in detecting pancreatic inflammation, even though some limitations concerning its specificity should be born in mind.     

Hormonal profile and serum zinc levels in uraemic men with gonadal dysfunction undergoing haemodialysis

Serum gonadal hormones, gonadotrophins and zinc levels were studied in thirteen men aged 29-62 yr with chronic renal failure undergoing haemodialysis. All patients had decreased libido and impotence. Serum testosterone levels in patients (18.5 +/- 1.3 (SEM) nmol/l) were significantly lower (p less than 0.05) than in the control group (24.1 +/- 2.2 (SEM) nmol/l) although salivary testosterone levels were strictly within the normal range. Mean serum 17-beta-oestradiol and luteinizing hormone levels (0.19 +/- 0.03 (SEM) nmol/l, and 57.4 +/- 13.1 (SEM) IU/l, respectively) were significantly higher (p less than 0.05 and p less than 0.005, respectively) than in the control group (0.11 +/- 0.02 (SEM) nmol/l and 14.8 +/- 1.9 (SEM) IU/l, respectively). Mean progesterone and follicle-stimulating hormone levels in patients were not significantly different from those of control subjects. Mean prolactin values in patients (1,019 +/- 285 (SEM) mIU/l) were significantly higher (p less than 0.01) than in the control group (211 +/- 24 (SEM) mIU/l). Serum prolactin levels in five patients were extremely high (above 1,200 mIU/l). There was no statistically significant difference in serum zinc levels between patients and controls. As salivary testosterone is normal, it seems that hyperprolactinaemia and raised serum 17-beta-oestradiol levels may be responsible, at least in part, for sexual dysfunction in male patients with chronic renal failure receiving haemodialysis.     

Elevated copper and lowered zinc in the placentae of pre-eclamptics

Selected cations (Ca, Co, Cu, Mg, Zn, Si, and K) were determined in the placentae of 18 women. Between pre-eclamptic and normal subjects there were significant (p less than 0.05) differences in copper and zinc concentrations and borderline significant differences in cobalt concentration. In the placentae of the ten women with a normal pregnancy, the average concentrations of copper and zinc were 53 and 192 micrograms atoms/kg placenta, respectively. In the placentae of 8 women with pre-eclampsia, the concentrations were 124 and 134 micrograms atoms/kg placenta for copper and zinc, respectively. Elevation of copper and decrease in zinc may be an exaggeration of normal pregnancy physiology that occurs in pre-eclampsia.     

Serum IgG4 concentrations in pancreatic and biliary diseases

BACKGROUND: Recently, it has been reported that the serum concentration of IgG4, a minor component of IgG subclasses, is increased in autoimmune pancreatitis. However, data regarding IgG4 concentrations in other pancreatic or biliary diseases have been insufficient. METHODS: Serum IgG4 was measured in 116 patients with pancreatic or biliary diseases (35 autoimmune pancreatitis, 24 chronic pancreatitis except autoimmune pancreatitis, 11 primary sclerosing cholangitis, 23 pancreatic cancer, 3 islet cell tumor, 2 papilla cancer, 15 bile duct cancer, and 3 gallbladder cancer patients). The cut-off concentration of IgG4 was 135 mg/dl. RESULTS: Increased serum IgG4 was observed in 33 of 35 patients with autoimmune pancreatitis, 0 of 24 with chronic pancreatitis, 4 of 11 with primary sclerosing cholangitis, 0 of 23 with pancreatic cancer, 0 of 3 with islet cell tumor, 0 of 2 with duodenal papilla cancer, 0 of 15 with bile duct cancer and 0 of 3 with gallbladder cancer patients. CONCLUSIONS: Serum IgG4 was increased in autoimmune pancreatitis and was within normal limits for other pancreatic or biliary diseases except primary sclerosing cholangitis.     

Clinical and echocardiographic correlates of serum copper and zinc in acute and chronic heart failure

Aim

Emerging evidence suggests a pathophysiological role of micronutrient dyshomeostasis in heart failure, including promotion of adverse remodeling and clinical deterioration. We sought to evaluate serum copper (Cu) and zinc (Zn) levels in acute (AHF) and chronic (CHF) heart failure.

Methods

We studied 125 patients, 71 % male, aged 69 ± 11 years, 37 % with preserved left ventricular ejection fraction (LVEF ≥40 %) (HFPEF), including 81 with AHF and 44 with CHF; 21 healthy volunteers served as controls. Serum Cu and Zn levels were determined using air–acetylene flame atomic absorption spectrophotometry.

Results

Serum Cu levels were significantly higher in AHF (p = 0.006) and CHF (p = 0.002) patients compared to controls after adjusting for age, gender and comorbidities, whereas they did not differ between AHF and CHF (p = 0.840). Additionally, serum Cu in patients with LVEF <40 % was significantly higher compared to both controls (p < 0.001) and HFPEF patients (p = 0.003). Serum Zn was significantly lower in AHF (p < 0.001) and CHF (p = 0.039) compared to control after adjusting for the above-mentioned variables. Moreover, serum Zn was significantly lower in AHF than in CHF (p = 0.015). In multiple linear regression, LVEF (p = 0.033) and E/e ratio (p = 0.006) were independent predictors of serum Cu in total heart failure population, while NYHA class (p < 0.001) and E/e ratio (p = 0.007) were independent predictors of serum Zn.

Conclusion

Serum Cu was increased both in AHF and CHF and correlated with LV systolic and diastolic function. Serum Zn, in contrast, was decreased both in AHF and CHF and independently predicted by clinical status and LV diastolic function.     

Patterns of insulin dependence in an African diabetic clinic.

Analysis of the age of onset of diabetes amongst insulin-treated patients in a large African diabetic clinic revealed a bimodal type of distribution, 23 per cent having an age of onset before 30 years and 77 per cent with onset at greater than or equal to 30 years of age. All 66 of the young insulin-treated group (21.7 +/- 4.8 years (mean +/- 1 SD)), and a random selection of 50 older insulin-treated patients (49.7 +/- 10 years), were studied. The older group were better controlled (HbA1 8.4 +/- 1.7 per cent vs. 10.8 +/- 2.6 per cent, p less than 0.001), on lower doses of insulin (49 +/- 23 vs. 71 +/- 23 u/day, p less than 0.001) and had higher body mass index (26.0 +/- 5.6 vs. 21.8 +/- 3.5, p less than 0.001). Serum C-peptide (0.24 +/- 0.15 vs. 0.07 +/- 0.10 nmol/l, p less than 0.0001), and C-peptide/glucose ratio (2.57 +/- 2.65 vs. 0.56 +/- 0.98 nmol/mmol x 10(2), p less than 0.001) were very significantly higher in older patients. Patients with later onset disease thus had better preservation of pancreatic function, higher body mass index and better glycaemic control on lower doses of insulin. These features suggest that older insulin-treated patients could in fact be 'Type 2' or non-insulin dependent patients, and the condition may be controllable with diet and/or oral hypoglycaemic agents, at least in some.     

Fractional urinary clearance of immunoreactive lipase in chronic pancreatic disease

Using an immunoenzymatic method, we studied lipase in the serum and urine of 23 controls, 22 chronic pancreatitis patients in symptomatic remission, and in 9 patients with proven pancreatic cancer. Serum and urine lipase and its fractional urinary clearance were compared with those of amylase and immunoreactive trypsin. Lipase immunoreactivity was detectable in the urine of 81.5% of the studied subjects (controls: 82%, chronic pancreatitis: 86%, pancreatic cancer: 66%); its output was higher than the upper limit of controls in 31.8% of chronic pancreatitis and in only 1 of pancreatic cancer, and it was significantly correlated with the urinary output of trypsin (r = 0.487, P less than 0.001), but not with that of amylase. A significant correlation was found between urinary output and serum levels for lipase, but not for trypsin or amylase. Fractional clearance of lipase was of the same magnitude as that of trypsin but only 0.1% that of amylase. 19% of chronic pancreatitis and pancreatic cancer showed a fractional clearance of lipase above the upper limit of controls, compared with 45% for trypsin and 3.2% for amylase. No difference in urinary clearance of the three enzymes was found between chronic pancreatitis and pancreatic cancer. In conclusion, although of no diagnostic relevance in pain-free patients with chronic pancreatic disease, this measurement can provide information on the mechanisms of renal excretion of pancreatic enzymes.     

Concentrations of calcium, copper, iron, magnesium, potassium, sodium and zinc in adult female hair with different body mass indexes in Taiwan.

We investigated concentrations of calcium, copper, iron, magnesium, potassium, sodium and zinc using atomic absorption spectroscopy in the hair of four groups of adult females (n = 392), ranging in age from 20 to 50 years, with different body mass index (BMI): BMI < 18, slim group; BMI 18-25, normal group; BMI 26-35, overweight or obese group; and BMI>35, morbidly obese group. We found that the group with BMI < 18 had the highest ratios for [Ca]/[Mg], [Fe]/[Cu] and [Zn]/[Cu], but the lowest ratio for [K]/[Na] in hair. On the contrary, the group with BMI > 35 had the highest ratio for [K]/[Na], but the lowest for [Fe]/[Cu] and [Zn]/[Cu] in hair. Furthermore, when we compared concentrations of Ca, Cu, Fe, Mg, K, Na and Zn between the groups with BMI < 18 and BMI > 35, we found that there were significant differences (p < 0.05) in zinc concentrations between these two groups. In addition, there were significant differences in Ca, Cu, Mg, K and Na concentrations, with p < 0.01 at least. From this point of view, we suggest that hair concentrations of Ca, Cu, Fe, Mg, K, Na and Zn may be correlated with adult female BMI, but further studies are needed.     

Sonographic evaluation of the pancreatic duct in normal children and children with pancreatitis.

We investigated the diameter of pancreatic duct using ultrasonography in 51 children with pancreatitis and age-matched healthy control children over a 5 year period. The diameters of pancreatic duct and pancreatic body were measured simultaneously by sonography. The mean ages of children with acute pancreatitis and chronic pancreatitis were 9.7 +/- 3.9 and 10.3 +/- 3.1 years, respectively (range, 1 to 8 years). The mean age of normal children was 9.6 +/- 5.3 years. A significant difference was found in diameter of the pancreatic duct between children with acute and chronic pancreatitis versus that of age-matched control. In addition, a significant difference in diameter of the pancreatic body was found between children with acute pancreatitis and age-matched controls, but there was no marked difference in diameter of the pancreatic body between normal persons and those with chronic pancreatitis. The mean diameters of the pancreatic duct in acute pancreatitis and chronic pancreatitis were 2.34 +/- 0.47 mm and 2.84 +/- 0.67 mm, respectively, which was greater than that of normal children (1.65 +/- 0.45 mm). Pancreatic ducts with diameters greater than 1.5 mm in children between 1 and 6 years, greater than 1.9 mm at ages 7 to 12 years, or greater than 2.2 mm at ages 13 to 18 years were significantly associated with the presence of acute pancreatitis. Thirty-two patients, including 25 with acute pancreatitis and 7 with chronic pancreatitis, underwent follow-up measurement of pancreatic duct and serum lipase examination on at least three occasions. A good correlation between the diameter of pancreatic duct and serum lipase level was found. Thus, ultrasonography of the pancreatic duct is valuable in diagnosis and monitoring of pancreatitis in children.     

应用ROC曲线评价Cu、Zn及 Cu/Zn比值对乳腺癌患者的诊断价值

目的探讨微量元素铜（Cu）、锌（Zn）浓度及其 Cu/Zn 比值在乳腺癌患者中的诊断价值、方法。方法测定55例乳腺癌患者和50例女性健康对照组全血Cu、Zn浓度及其比值,并应用 ROC曲线分析评价Cu、Zn浓度及其比值对乳腺癌的诊断性能。结果乳腺癌患者全血Cu和 Cu/Zn比值均明显高于健康对照组,而血Zn浓度则显著低于健康对照组,且两组相比差异有显著性（P＜ 0.05）。ROC曲线分析显示,Cu、Zn及 Cu/Zn比值诊断乳腺癌的 ROC曲线下的面积分别为0.735、0.673和0.930。相比之下Cu/Zn比值对诊断乳腺癌有最佳的诊断效率。结论全血Cu、Zn浓度及Cu/Zn比值可能是乳腺癌的辅助诊断指标,但真正有诊断价值的指标是Cu/Zn比值。     

Can plasma human pancreatic polypeptide be used to detect diseases of the exocrine pancreas?

Plasma concentrations of human pancreatic polypeptide (HPP) parallel exocrine pancreatic secretion in response to stimulation with cholecystokinin. We determined prospectively the relationships among fasting HPP level, integrated HPP response to infusion of cholecystokinin, and output of trypsin and also the sensitivity, specificity, and predictive values of the fasting HPP level in the diagnosis of exocrine pancreatic disease. Our study group consisted of 19 patients with acute pancreatitis, 17 with chronic pancreatitis, and 25 with ductal adenocarcinoma of the pancreas and 27 control subjects. In the control patients and those with chronic pancreatitis, significant correlations were detected between HPP level and output of trypsin (P less than 0.001) in response to infusion of cholecystokinin and between fasting HPP and integrated HPP levels (P less than 0.004); no correlation was detected between HPP level and steatorrhea. The sensitivity, specificity, and negative and positive predictive values of the fasting HPP level for detection of either chronic pancreatitis or pancreatic cancer were similar and approximated 0.88, 0.67, 0.88, and 0.66, respectively. The HPP concentration had no value in detecting acute pancreatitis. Because the fasting HPP level has a high degree of negative predictability and is simpler to measure than the integrated HPP level or the output of trypsin, it may be a useful test in patients suspected of having either chronic pancreatitis or pancreatic cancer. A fasting HPP level of 125 pg/ml or greater could be used to exclude chronic pancreatitis or pancreatic cancer, but the finding of a value of less than 125 pg/ml necessitates use of other diagnostic tests for reliable determination of the presence of these diseases.     

Serum carboxypeptidase A activity as a biomarker for early-stage pancreatic carcinoma

BACKGROUND: The early stage of pancreatic carcinoma lacks typical clinical signs and symptoms, and is difficult to diagnose. We developed an assay for active form of serum carboxypeptidase A (F-CPA) and its zymogen precursor pro CPA, and evaluated them as a marker for early-stage pancreatic carcinoma. METHODS: Serum CPA from 406 patients including 169 with pancreatic carcinoma, 53 with acute pancreatitis, 23 with chronic pancreatitis, and 161 with non-pancreatic diseases were assayed by a method with N-acetyl-phenylalanyl-l-3-thiaphenylalanine as substrate and dl-benzylsuccinic acid as specific inhibitor of CPA. Activation of pro CPA was carried out using trypsin. RESULTS: An established assay system was performed fully automatically and possesses enough performance for routine clinical assay. This system requires 31 minutes for CPA detection. No significant differences were detected between the F-CPA activity of patients with pancreatic carcinoma and that of patients with non-pancreatic diseases (p=0.168). F-CPA was mainly increased in patients with pancreatitis. Since total-CPA (T-CPA, T-CPA=pro CPA+F-CPA) was increased both in patients with pancreatic carcinoma and those with acute pancreatitis (p<0.0001, each case), the F-CPA/T-CPA ratio was low only in the patients with pancreatic carcinoma. The rate of positivity of T-CPA in the early stage of pancreatic carcinoma in which tumor was less than 2 cm was 77%, and higher than those of CA19-9 (31%), CEA (8%), and elastase 1 (46%). CONCLUSION: It was suggested that assays of both T-CPA and F-CPA in serum might be useful for the surveillance of early-stage pancreatic carcinoma.     

Serum zinc and copper concentrations in low birth weight infants during first three months of life: correlation to birth weight and different feedings

Serum zinc (Zn) and copper (Cu) concentrations were measured in infants weighing 740 g to 2,500 g at birth. They were divided into three groups depending on their birth weight; Group I ranged from 740 to 1,500 g (N = 35), Group II from 1,501 to 2,000 g (N = 26), and Group III from 2,001 to 2,500 g (N = 19). They were fed breast milk (N = 24), commercially available non-supplemented formula with low Zn and low Cu content (N = 42), or Zn- and Cu-supplemented formula (N = 14). Serum Zn levels of breast fed infants were apparently higher than those of the other two different formula fed infants, the difference being significant at 1 month of age in Group I. After the decline of serum Zn level during the first month of life, the level in Groups II and III remained unchanged, whereas the level in Group I further declined progressively until 3 months of age. An incidence of hypozincemia (0.65 micrograms/ml) was highest in Group I, medium in Group II, and lowest in Group III. The serum Cu level was elevated progressively after birth in all groups, but the mean level was consistently highest in Group III, medium in Group II and lowest in Group I. No difference in serum Cu level was found among the infants with different feedings.     

Sequential concentrations of copper and ceruloplasmin in serum from preterm infants with rickets and fractures

Concentrations of copper (Cu) and ceruloplasmin in serum were measured serially in 49 preterm infants with mean (+/- SEM) birth weights of 979 +/- 33 g and gestational ages of 28.4 +/- 0.3 weeks at three, six, nine, and 12 months postpartum. Serial radiographic studies showed 17 infants with (group A) and 32 infants without (group B) rickets or fractures. Cu and ceruloplasmin concentrations in serum also were measured in 21 healthy term infants (group C) with birth weights 3668 +/- 98 g at three, six, and 12 months postpartum. Analyses of covariance of serial changes in these serum variables--taking into account such potential covariates as differences in gestational age, birth weight, initial weight and length, changes in weight and length during the study, the duration of parenteral nutrition, and increased enteral copper intake--showed both groups of preterm infants had significantly lower concentrations of Cu in serum up to age six months and ceruloplasmin up to age three months (P less than 0.001) when compared with term infants. By one year of age, Cu and ceruloplasmin concentrations in serum in all groups had increased significantly (P less than 0.001), into the adult range, and were not significantly different among groups. These data document a maturational lag in copper metabolism in small, preterm infants. Changes in concentrations of Cu and ceruloplasmin in serum were significantly correlated (r = 0.92, P less than 0.001) but were not significantly different between preterm infants with and without rickets or fractures at each age.     

Plasma trypsin in chronic pancreatitis and pancreatic adenocarcinoma.

We have used a simple and precise radioimmunoassay to measure trypsin in human plasma. Fasting plasma trypsin concentrations were extremely low in patients with chronic pancreatitis with steatorrhoea (5 +/- 2 ng/ml) when compared to healthy controls (86 +/- 7 ng/ml, p less than 0.001). In patients with chronic pancreatitis but no steatorrhoea basal plasma trypsin levels were similar to those of the normal controls (99 +/- 25 ng/ml). A small but significant postprandial rise in plasma trypsin concentrations was observed in normal subjects (mean increment 15 +/- 4%, p less than 0.005, paired t test) but was absent in patients with chronic pancreatitis with steatorrhoea. In contrast to exocrine deficient chronic pancreatitis, other malabsorptive conditions associated with steatorrhoea (active coeliac disease and acute tropical sprue) demonstrated mean fasting trypsin concentrations similar to controls. Patients with adenocarcinoma of the pancreas had basal trypsin concentrations similar to healthy subjects as did patients with adenocarcinoma of the stomach, colon, rectum, brochus, and breast. In some cases measurement of plasma trypsin may be of help in the differential diagnosis of steatorrhoea.     

妇女妊娠期血清锌铜铁含量的测定及其临床意义

目的 探讨妇女妊娠期血清锌、铜、铁含量的变化及其临床意义.方法 采用原子吸收光谱法分别检测各类孕妇共567例血清锌铜铁含量,并与53例正常对照组进行比较分析.结果 正常孕妇早期妊娠血清锌、铁元素含量与对照组比较稍有下降,但差异无统计学意义(P＞0.05),中、晚期孕妇、妊娠高血压病、产后出血的孕产妇锌、铁均明显低于对照组(P＜0.01),血清铜随着妊娠月份增加而明显上升(P＜0.01).结论 锌、铜、铁是妇女妊娠期所必需的微量元素,对胎儿的生长发育具有重要作用.     

Clinical usefulness of serum tartrate-resistant acid phosphatase activity determination to evaluate bone turnover.

The study was carried out to evaluate the clinical validity and usefulness of serum tartrate-resistant acid phosphatase (TRAP) activity determined using an improved spectrophotometric assay. Enzyme activity was measured in 84 normal subjects and in 109 patients with common metabolic bone diseases. Mean values of serum TRAP activity in male subjects (n = 19; 10.4 +/- 2.15 U l-1) were not significantly different from those found in female subjects (n = 65; 10.8 +/- 1.8 U l-1). In the latter group mean values were significantly raised in post-menopausal subjects (10.5 +/- 2.0 U l-1; p less than 0.01) compared with mean values in pre-menopausal women (8.45 +/- 1.8 U l-1). We found a significant inverse correlation between serum TRAP activity values and bone mineral density (BMD) measured both at an ultradistal radial point (n = 33, r = -0.506; p less than 0.01), and at the lumbar spine (n = 57, r = -0.261; p less than 0.05). Mean serum TRAP activity values in patients with metabolic bone diseases were: primary hyperparathyroidism, n = 30: 14.2 +/- 4.89 U l-1, p less than 0.001 vs normal subjects; chronic maintenance haemodialysis, n = 19: 17.4 +/- 6.7, p less than 0.001; metastatic cancer, n = 13: 21.2 +/- 6.3, p less than 0.001; post-surgical hypoparathyroidism, n = 10: 9.9 +/- 1.8, NS; involutional osteoporosis, n = 20: 12.5 +/- 2.3 p less than 0.001; Paget's disease, n = 10: 16.8 +/- 3.5, p less than 0.001; osteomalacia, n = 7: 19.5 +/- 3.31, p less than 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)