Effect of chronic DDC treatment on LHRH and substance P amidation processes in the rat

We examined the effects of chronic diethyldithiocarbamate (DDC) treatment on the concentrations of methionine-enkephalin, mature and unamidated forms (-Gly) of luteinizing hormone releasing hormone (LHRH) and substance P (SP) in various regions of the central nervous system (CNS). Chronic DDC treatment resulted in elevations of LHRH-Gly like immunoreactivity in the preoptic area (POA) and the medial basal hypothalamus (MBH), as well as elevations in SP-Gly like immunoreactivity in all areas of the CNS examined. Castration altered the ratios of SP-G-like/SP-like immunoreactivity in the pons, and LHRH-Gly like immunoreactivity in the MBH. Met-enkephalin concentrations were significantly elevated in the pons and medulla of intact DDC-treated animals, and in the POA of both intact- and castrated DDC-treated animals. Results demonstrate that it is possible to detect basal levels of unamidated LHRH and SP in many areas of the CNS, with ratios of unamidated/amidated peptides representing a unique and sensitive method for determining altered posttranslational processing of these transmitters, especially under altered endocrine states such as castration. Pharmacological blockade of terminal enzymatic processing of these peptides may be useful in studying upstream regulatory events in peptidergic neurons.

Circulating 131I thyroxine and thyroid cancer

We have developed a blood test to detect the presence of thyroactive tissues in patients being evaluated for ablative therapy of differentiated thyroid carcinomas. This test is based on the assumptions that if any thyroactive tissue is present, some radioactive T4 will be manufactured after administration of radioiodide, and that some of it will be released into the circulation. Twenty serum samples obtained from 19 patients at the time of total body 131I scanning to evaluate for the need of further 131I therapy were analyzed chromatographically, together with an internal 125I T4 marker, for the presence of 131I-labeled T4. Three patients also were studied 7 days after a treatment dose of 131I, when they returned for posttreatment scan. The chromatographic method used (Sep-Pak followed by HPLC) removes all radioiodide from the T4 fraction, so the results were interpreted as negative or positive based upon the absence or presence of detectable counts in the T4 fraction. Twelve patients (16 studies) with positive total body 131I scans all demonstrated circulating 131I T4. Seven patients with negative whole body scans were all negative for 131I T4. On the other hand, 2 patients with positive thyroglobulin assays had negative total body scans and 131I T4 tests. Both of them had independent evidence of the presence of thyroid cancer that did not concentrate radioiodine. Three patients had positive scans and 131I T4 tests but negative thyroglobulin assays. We conclude that measurement of circulating radioactive T4 is a sensitive test for the presence of normal or malignant thyroactive tissues which are likely to respond to 131I ablation.

Heme oxygenase induction. A possible factor in aluminum-associated anemia

The effect of repeated parenteral administration of aluminum (Al) was investigated to determine if a relationship exists between the severity of anemia and increase in hepatic heme oxygenase activity. Female Swiss Webster mice were dosed for 11 d with 50 mg Al/kg, as Al lactate, and sodium lactate was given to control mice. On d 12, hematocrit, hemoglobin, blood smears, hepatic heme oxygenase activity, and cytochrome P450 levels were assessed. Significant decreases in hematocrit (39.1 +/- 0.7 vs 43.1 +/- 0.3% in controls) and hemoglobin (13.1 +/- 0.4 vs 14.2 +/- 0.2 g/dL in controls) were produced by Al administration. Blood smears from Al-treated mice consistently showed smaller, more irregular red cells. Cytochrome P450 content was significantly decreased (0.443 +/- 0.043 vs 0.665 +/- 0.055 nmol/mg) whereas hepatic heme oxygenase activity was significantly increased (2.75 +/- 0.34 vs 1.66 +/- 0.20 nmol/mg/h) in Al-treated animals. The production of mild anemia by parenteral aluminum correlated significantly with the increase in heme oxygenase activity, which, although only 66% greater than in control, preceded a significant loss of cytochrome P450. The increased heme oxygenase activity, with subsequent increased destruction of heme and/or heme proteins is discussed as a possible mechanism for the microcytic, hypochromic anemia associated with Al overload.

Vasodilator effects of parathyroid hormone, parathyroid hormone-related protein, and calcitonin gene-related peptide in the human fetal-placental circulation

OBJECTIVE

The purpose of our study was to determine the vasoactivity of calcitonin gene-related peptide (CGRP), parathyroid hormone (PTH), and parathyroid hormone-related protein (PTHrP) in the human fetal-placental circulation in vitro.

METHODS

Dually perfused placental cotyledons from term pregnancies were used in this study.

RESULTS

Calcitonin gene-related peptide, PTHrP (both 10(-10)-10(-6) mol/L), and PTH (10(-8)-10(-6) mol/L) demonstrated a significant concentration-dependent vasodilator effect (P = .0007, P = .0172, P = .0063, respectively), following preconstriction with a thromboxane mimetic U46619. The CGRP-1 receptor inhibitor CGRP8-37 (10(-6) mol/L) significantly inhibited (P = .0131) the CGRP-induced vasodilator effect, while the nitric oxide synthesis inhibitor n-nitro-l-arginine showed no inhibitory effect.

CONCLUSIONS

These results demonstrate the vasodilator effects of CGRP, PTH, and PTHrP in the human fetal-placental circulation. Calcitonin gene-related peptide and PTHrP were of equal potency, and both were approximately 100 times more potent than PTH. This study also suggests the CGRP may exert its vasodilator effect through two classes of receptors in the human placenta and may do so independently of nitric oxide.

Immunotoxicity of 180 day exposure to polydimethylsiloxane (silicone) fluid, gel and elastomer and polyurethane disks in female B6C3F1 mice

Millions of people have been exposed to silicones which are present in consumer goods such as cosmetics and toiletries, processed foods and household products. In addition, silicones have been used extensively in medical practice as a lubricant in tubing and syringes, and as implantable devices. A silicone widely used in medical practice is polydimethylsiloxane. This study was undertaken to determine the immunotoxicologic potential of long term exposure to the principal constituents of breast implants: silicone fluid, silicone gel and silicone elastomer. An alternative covering for devices containing silicone gels, polyurethane, was also included in the study. Silicone fluid and gel were injected subcutaneously into female B6C3F1 mice (1 ml/mouse) and 6 mm disks of silicone elastomer or polyurethane were implanted subcutaneously. There were no treatment-related deaths or overt signs of toxicity during the 180 day exposure. None of the tested materials had notable effects on body or organ weights, erythrocytes or leukocytes in the blood, blood chemistries such as alanine aminotransferase, urea nitrogen, glucose, albumin or total protein, or serum CH 50 or C3 levels. The cellularity of the bone marrow and responses to CSF-GM and CSF-M were normal. The tested silicones and polyurethane marginally reduced the level of Ig+ cells in the spleen but did not consistently alter the distribution of T cell surface markers. The antibody response to sheep erythrocytes was not markedly altered, nor were proliferative responses to concanavalin A, phytohemagglutinin, lipopolysaccharide or allogeneic cells. Reticuloendothelial function was normal, as was phagocytosis of chicken erythrocytes and Covaspheres by adherent peritoneal cells. Natural killer cell activity was depressed in all silicone treatment groups and in mice implanted with polyurethane. No silicone or polyurethane treatment group displayed altered susceptibility to a challenge with Listeria monocytogenes, Streptococcus pneumoniae or the B16F10 tumor. The only consistent effect of 180 day exposure to silicone materials or polyurethane was a modest depression of natural killer cell activity.

Neutron activation analysis for the determination of trace elements in biological materials

Neutron activation analysis, in both its radiochemical and instrumental forms, is a precious technique for the determination of trace elements in biological materials. Probably its most important advantage is its relative freedom from errors resulting from contamination of the samples. Invaluable characteristics are also its excellent sensitivity, outstanding selectivity, and remarkable multielement capability. It is, however, necessary to warn against uncritical expectations. This is best illustrated by the seriously inconsistent results obtained in several laboratories. Because of the necessity to have access to a nuclear research reactor, the stringent safety rules to be observed, the rather high costs of the analyses, the relatively low sample throughput, and the sometimes long delay between the taking of a sample and the obtaining the final result, the use of neutron activation analysis remained restricted to a few--essentially research--laboratories. It found its main application in solving arduous problems and in paving the way for other analytical techniques better suited to routine applications.

Salivary cortisol in psychoneuroendocrine research: recent developments and applications

The assessment of cortisol in saliva has proven a valid and reliable reflection of the respective unbound hormone in blood. To date, assessment of cortisol in saliva is a widely accepted and frequently employed method in psychoneuroendocrinology. Due to several advantages over blood cortisol analyses (e.g., stress-free sampling, laboratory independence, lower costs) saliva cortisol assessment can be the method of choice in basic research and clinical environments. The determination of cortisol in saliva can facilitate stress studies including newborns and infants and replace blood sampling for diagnostic endocrine tests like the dexamethasone suppression test. The present paper provides an up-to-date overview of recent methodological developments, novel applications as well as a discussion of possible future applications of salivary cortisol determination.

Automated determination of glycated hemoglobin: comparative evaluation of five assay systems

We evaluated four newly introduced assays for determination of glycated hemoglobin allowing the processing of large amounts of samples in a clinical routine laboratory. These methods were compared to the Bio-Rad Diamat system. The investigated methods were the Merck Hitachi L-9100, a fully automated HPLC analyser, the Abbott IMx glycated hemoglobin ion capture assay, the DAKO HbA1c enzyme linked immunosorbent assay (ELISA), and the Boehringer-Mannheim HbA1c Tinaquant turbidimetric assay. All methods showed generally acceptable precision and good accordance with the Diamat system. Interference study showed influence of anaemia, polycythemia, rheumatoid factor, and chronic hemodialysis on the values of the DAKO ELISA and of anaemia and polycythemia on the values of the Boehringer-Mannheim Tinaquant assay. All of the investigated methods allow referring of results either as measured or standardized HbA1c values, the latter obtained after calibration with reference to an ion exchange high-pressure liquid chromatography method. Our data confirm the feasibility of this kind of standardisation of glycated hemoglobin assays, allowing direct comparison of results from various determination methods.

Molecular physiology of amylin

Amylin is a 37-amino acid peptide first isolated, purified, and characterized from the amyloid deposits in the pancrease of type 2 diabetics. It is synthesized and secreted primarily from pancreatic beta cells along with insulin. The ability of amylin to potently reduce insulin-stimulated incorporation of glucose into glycogen in skeletal muscle requires both an intact 2Cys-7Cys disulfide bond and a COOH-terminal amide. Amylin has structural and functional relationships to two other messenger proteins, calcitonin and CGRP. Amylin has relatively potent calcitonin-like activity on bone metabolism and weaker CGRP-like activity on the vasculature. CGRP is a slightly weaker agonist than amylin for metabolic responses. Although rat calcitonins are weak, teleost fish calcitonins are very potent agonists for amylin's metabolic effects. This group of peptides appears to act on a family of related G protein-coupled receptors; several variant calcitonin receptors have recently been cloned and expressed. These receptors appear to be coupled to adenylyl cyclase in many instances; recent evidence supports the view that amylin's effects on skeletal muscle occur, at least in large part, through activation of the cAMP pathway.

Transforming growth factor beta increases ecto-nucleoside triphosphate pyrophosphatase activity of human bone-derived cells

Inorganic pyrophosphate (PPi) may be involved in the regulation of mineralization. The cell surface enzyme, ecto-NTP pyrophosphatase, could be a major source of extracellular PPi in bone, and agents that influence its activity in osteoblasts may modulate bone mineralization. We studied the effects of serum on the ecto-NTP pyrophosphatase activity of cultured human osteoblast-like cells. Enzyme activity was lowered when the concentration of fetal calf serum (FCS) was reduced from 10 to 2.5% (vol/vol) for 48 h, and a further decrease in activity was observed after 96 h. Relative to enzyme activity in cells cultured in serum-free medium for 96 h, adult human platelet-poor plasma (HPPP; 2.5-10% vol/vol) induced a small increase, similar concentrations of adult human serum (HS) induced much larger increases, and charcoal-depleted FCS was ineffective. In an attempt to identify the factor(s) present in serum that influence ecto-NTP pyrophosphatase activity, we examined transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF). PDGFs AA, AB, and BB (0.1-10 ng/ml) were ineffective, but both TGF-beta 1 and TGF-beta 2 increased enzyme activity. The increase was dose dependent between 0.001 and 10 ng/ml, was enhanced in the presence of 2% vol/vol FCS, and was not potentiated by PDGF or by 1,25-(OH)2D3. Furthermore, the increase was independent of cell density and was blocked by inhibitors of protein and RNA synthesis. Ecto-NTP pyrophosphatase of subject-matched human dermal fibroblasts was unaffected by TGF-beta (10 ng/ml), suggesting that modulation of activity by the growth factor may be tissue specific. Alkaline phosphatase (ALP) probably serves to hydrolyze extracellular PPi in bone. In contrast to effects on NTP pyrophosphatase activity is osteoblast-like cells, TGF-beta 1 and TGF-beta 2 (0.001-10 ng/ml) decreased ALP activity dose dependently after 72 h. By inducing opposing changes in ecto-NTP pyrophosphatase and ALP activities, TGF-beta may increase extracellular PPi concentrations in osseous tissues and consequently modulate bone mineral properties in vivo.

On-line immunoanalysis for bioprocess control

Immunoanalytical techniques such as ELISA are often used for the detection of proteins produced in cultivation processes. Owing to the difficulty of automating of the time-consuming traditional ELISA, there is an intense demand for a suitable on-line monitoring method. Combining well-known immunoassays with the FIA technique, we present the heterogeneous and the turbidimetric immuno-FIA methods. The following proteins were investigated with these FIA methods: thermostable pullulanase, IgG, antithrombin III, and recombinant tissue-type plasminogen activator. In the cases of pullulanase and monoclonal mouse IgG, the turbidimetric immuno-FIA was used for on-line analysis of the cultivation process. Results are presented here to demonstrate the effectiveness and application of these immunoanalysis.

Monoclonal antibody to liver metallothionein: a novel marker for myoepithelial cells

Myoepithelial cells (MEC) are situated between acinar or ductal luminal cells and the basal lamina in various secretory glands, including salivary gland. The in-situ demonstration of MEC in benign and malignant conditions has long been hampered by the lack of suitable markers, most of which do not label MEC exclusively. We report here the reactivity of L2E3, a monoclonal antibody directed against liver metallothionein (MT). In the major and minor salivary glands, L2E3 stained two types of cells: a slender, elongated cell that surrounded acini; and a small, basal, cuboidal cell observed in the excretory (interlobular) ducts. Our results indicate that L2E3 represents a novel, useful marker for the immunohistochemical identification of MEC, and a highly sensitive marker for ductal basal or "reserve" cells in salivary glands.

Serum alanine aminotransferase (ALT) elevation in asymptomatic US Air Force basic trainee blood donors

The purpose of this study was to determine the etiology of elevated alanine aminotransferase (ALT) in a population of asymptomatic volunteer blood donors. Subjects with an ALT value > 2.25 sd above norm (> 55 IU/liter) from the donated unit, were prospectively evaluated over a six-week interval. The subjects consisted of blood donors (78% male, 22% female) beginning basic military training at Lackland Air Force Base. Of 44,160 individuals screened, 19,877 (45%) voluntarily donated blood, 99 (0.5%) of which had confirmed ALT elevation. Of these (90 male/9 female), an associated condition or explanation was made in 12%: four with acute hepatitis B, four positive for anti-HCV, two with autoimmune disease, one with cholelithiasis and one associated with acute appendicitis. In 87 the ALT elevation could not be explained using available testing methods but may represent individual variation from a non-Gaussian distribution, be of nonhepatic origin (muscle), or of hepatic disease not detected by the diagnostic algorithm used. To increase the diagnostic yield, it is suggested that at least two elevated ALT values be established in this population over a period of time (yet undefined), before an extensive hepatic investigation is pursued.

Effect of orally administered monoclonal antibody on persistent Cryptosporidium parvum infection in scid mice

Scid mice, persistently infected after exposure to 10(7) Cryptosporidium parvum oocysts, were treated daily for 14 to 17 days with 0.4 mg of monoclonal antibody (mAb) 17.41 administered by the oral route. Mice receiving mAb 17.41 shed significantly fewer (P < 0.005) C. parvum oocysts than scid mice receiving isotype control mAb. Intestinal (but not gastric) infectivity scores were also reduced for scid mice treated with mAb 17.41 (P < 0.01).

Comparison of two preservation solutions for erythrocyte transfusions in newborn infants

To determine whether one of the newer preservation solutions for packed red blood cells (PRBC) is safe and effective in the transfusion of the very low birth weight infant, we conducted a randomized trial comparing PRBC preserved with the anticoagulant solution mannitol-adenine-dextrose (AS-1) and PRBC preserved with citrate-phosphate-dextrose-adenine (CPDA-1). Sixteen infants (birth weight 863 +/- 218 gm) with a gestational age of 26 +/- 3 weeks received one to three small-volume replacement transfusions with PRBC, 17 ml/kg, preserved with either AS-1 or CPDA-1 in a double crossover design. Transfusion with AS-1-preserved PRBC resulted in an equivalent increase in hemoglobin concentration when adjustment was made for the difference in the hemoglobin concentration of the transfused PRBC. During the transfusion, the percentage decrease in serum glucose values was greater with the CPDA-1 preservative than with the AS-1 preservative (54% +/- 13% vs 42% +/- 11% at 1 hour; p < 0.001). No other significant difference in blood chemistry values was found. Urine output was unaffected by AS-1 in the posttransfusion period. We conclude that (1) small-volume PRBC transfusions with AS-1 can be used in the very low birth weight infant without apparent detriment, (2) AS-1-preserved cells are as effective as cells preserved with CPDA-1 for increasing hemoglobin concentration, and (3) the higher dextrose content of the AS-1-preserved blood allows for improved glucose homeostasis during transfusion.

Hepatotoxic effects of ethanol and phenformin association in rats

1. The association of ethanol and phenformin during 6 months in the Sprague-Dawley rat produces an alteration in lactate homeostasis. A basal blood lactate value of 54.13 +/- 15.43 mg/dl was found compared to 23.65 +/- 7.4 mg/dl in control rats. 2. Lactic acid levels increased to 28.8 +/- 7.42 mg/dl and 22.01 +/- 8.08 mg/dl after chronic administration of ethanol or phenformin in Sprague-Dawley rats, respectively. Nevertheless, these were not statistically significant with respect to those of control group. 3. The total hepatic collagen content after chronic administration of phenformin and ethanol was moderately elevated 7.12 +/- 1.85 mg/g of wet tissue, and statistically significant with respect to the control group, 4.77 +/- 1.17 mg/g. Collagen content values in phenformin and ethanol rats did not reveal statistically significant differences. 4. Liver showed histological degenerative changes but not any sign of fibrosis after chronic administration of ethanol and phenformin together.

Protein synthesis in the major salivary glands of the rat and the effects of re-feeding and acute ethanol injection

Rates of protein synthesis in the major salivary glands of the rat were accurately determined in vivo using the 'flooding dose' technique and the effects of reflex stimulation through feeding or acute ethanol treatment were assessed. Rats were divided into three groups. The control group was fasted overnight, the re-fed group was also fasted then re-fed the following morning and the third group received an intraperitoneal injection of ethanol after an overnight fast. In control rats the sublingual gland had a higher rate of protein synthesis than the other glands. After a feed the rate of protein synthesis in parotid glands was approximately double that of controls whilst that of the submandibular glands had increased by 24% and the sublingual glands remained unchanged. Acute ethanol injection led to a reduced rate of protein synthesis in all glands. The higher rate of protein synthesis in sublingual glands under fasting conditions may be related to the spontaneous secretion of fluid and protein from this gland, which would require a constant replenishment of secretory protein by synthesis. Protein synthesis in the parotid gland, like secretion, appears to be closely linked with the reflex stimulation caused by mastication. The smaller increase in rate of protein synthesis seen in the submandibular gland after a re-feed does not appear to have been recorded before. It could be mediated by the increased reflex stimuli caused by mastication or by some circulating factor. The mechanism by which ethanol reduces protein synthesis in all glands is uncertain.

Measurement of bone mass and turnover

Bone mass is the most important determinant of fracture risk. Current bone mass of an individual will be determined by the peak bone mass achieved in early adult life and the subsequent duration and rate of bone loss. In attempting to predict an individual's future risk of fracture it is therefore logical to attempt to assess both of these parameters. Serial measurements of bone mineral density and estimation of the rate of bone turnover may also be used to determine the response to treatment. In this chapter we review the currently available methods of measuring BMD and bone turnover, and discuss their place in the diagnosis and management of osteoporosis.

Analysis of saturated phosphatidylcholine in amniotic fluid by 31P NMR

A technique using solubilization with sodium cholate to resolve 31P NMR resonances of phospholipid molecular species was applied to amniotic fluid samples from 16 subjects. Gestational ages from 25 to 40 weeks were represented, and two subjects were sampled sequentially. Fitting of the partially resolved 31P NMR signal of phosphatidylcholine (PC) generated an estimate of percent disaturated acyl PC (%dsPC) which correlated more highly with gestational age than did several other potential indices of fetal lung maturation, such as the ratio of PC to inorganic phosphate from the solubilized spectra, or PC to sphingomyelin from extract spectra. In a few cases, enzyme-catalyzed PC hydrolysis limited the precision, but did not appear to affect the accuracy, of the %dsPC estimates. Resolution of palmitoyl and oleoyl lyso-PC species was observed for both the 1- and 2-acyl isomers. Upfield shifts due to the presence of cis double bonds in the lone acyl chain of the lyso-PCs were analogous to those observed for the diacyl PCs.

Applicability of the critical difference

The present study is concerned with the critical difference, which may help to judge whether or not the difference between two consecutive measurements with a certain probability (i.e. 95 percent) may be ascribed to natural variation. Knowledge of the applicability of the critical difference in veterinary medicine is sparse and therefore, to justify future use of the critical difference, it is important to know whether or not the critical difference performs as expected. The hypothesis to be tested in this study was that at least 95 percent of the differences between consecutive measurements, that have been obtained in animals where the component measured is known to be unchanged, should be within the critical difference. From previous studies it was known that a low-sodium diet had no influence on the plasma potassium concentration. The critical difference of the plasma potassium concentration in dogs was calculated as 0.5 mmol/l. using weekly measurements of this plasma component in a group of twenty healthy dogs. To test the hypothesis, this value was compared to the differences between consecutive weekly measurements of this plasma component in another group of eight dogs fed a low-sodium diet for five weeks. In agreement with previous studies, the plasma potassium concentration in the eight dogs did not change significantly during the feeding experiment. Of the fourty differences between consecutive weekly measurements, thirty-six were within the critical difference. This number was not different from the number expected from the hypothesis and thus, the critical difference performed as expected.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumin levels in pregnancy: a hypothesis--decreased levels of albumin are related to increased levels of alpha-fetoprotein

Serum albumin levels decrease during pregnancy while the concentration of most other maternal serum proteins of hepatic origin remain stable or increase. In a study of 289 women, most maternal characteristics such as race, age, smoking, a history of previous low birth-weight, infant sex and gestational age at delivery were not related to maternal serum albumin levels at 18 or 30 weeks' gestational age. The degree of maternal obesity significantly correlated with the concentration of albumin. There was a significant negative correlation in individual women between maternal serum levels of albumin and alpha-fetoprotein, with high levels of maternal serum alpha-fetoprotein predicting lower levels of albumin. We hypothesize that there may be a negative feedback effect of alpha-fetoprotein of fetal origin on the maternal production of albumin during pregnancy.

Extrahepatic peribiliary glands express alpha-amylase isozymes, trypsin and pancreatic lipase: an immunohistochemical analysis

We examined expression of alpha-amylase isozymes (pancreatic and salivary), trypsin and pancreatic lipase on the epithelium of extrahepatic peribiliary glands immunohistochemically using 53 autopsied normal extrahepatic bile ducts. Three parts of the extrahepatic bile duct (common bile duct, intrapancreatic bile duct and bile duct at the ampulla of Vater) were examined in each case. Histologically, the extrahepatic bile duct harbored branched tubular glands (extrahepatic peribiliary glands). Extrahepatic peribiliary glands were few in the common bile duct and intrapancreatic bile duct and numerous in the bile duct at the ampulla of Vater. Immunohistochemically, pancreatic alpha-amylase was expressed in the epithelium of extrahepatic peribiliary glands in 42 cases (79%). Salivary alpha-amylase was expressed in the epithelium of the glands in 38 cases (72%). Trypsin was expressed in the epithelium of the glands in 32 cases (60%). Pancreatic lipase was expressed in the epithelium of the glands in 45 cases (85%). The immunoreactivity of these enzymes was granular and located in the supranuclear cytoplasm (corresponding to the Golgi apparatus) of the epithelium of the glands. We confirmed the specificity of the immunoreactivity of these enzymes with various methods. These results suggest that extrahepatic peribiliary glands produce alpha-amylase isozymes, trypsin and pancreatic lipase and secrete these enzymes into lumens of the extrahepatic bile duct. The secreted enzymes may play an important role in the physiology of the extrahepatic bile duct and bile.

Amylin in bone conservation current evidence and hypothetical Considerations

Amylin, a 37-amino-acid long single-chain polypeptide, is structurally homologous to calcitonin and calcitonin gene-related peptide (CGRP). The peptide is secreted from pancreatic beta cells and is thought to have an anti-insulin action. Here, we review the recently described effects of amylin on calcium homeostasis and discuss its possible role in bone conservation. Amylin is a potent hypocalcemic and antiresorptive peptide. Studies using isolated osteoclasts have revealed that amylin inhibits cell motility (Q effect), without affecting cell spread area or elevating cytosolic [Ca(2+)]. Thus, amylin action is similar to that of calcitonin, but lower in potency. Lower circulating concentrations of amylin in type-1 diabetes may cause the bone loss associated with this condition.

The role of high-density lipoprotein and lipid-soluble antioxidant vitamins in inhibiting low-density lipoprotein oxidation

1. The oxidation of low-density lipoprotein (LDL) is believed to play a central role in atherogenesis. We have compared the effect of antioxidant vitamins and high-density lipoprotein (HDL) on the Cu(2+)-catalysed oxidation of LDL. 2. Antioxidant vitamin supplementation significantly reduced conjugated diene formation but did not affect the formation of lipid peroxides. 3. Conversely, HDL did not affect conjugated diene formation but inhibited the formation of lipid peroxides by up to 90%. 4. The inhibition by HDL of lipid peroxide formation in oxidized LDL was dependent on the concentration of HDL and was not due to HDL chelating Cu2+. 5. Large interindividual variations in the inhibition of lipid peroxide formation by autologous HDL were evident, which were related to the rate of lipid peroxide generation in the LDL. 6. We conclude that HDL is a powerful antioxidant or more probably inhibitor of LDL oxidation in vitro and may play an important role in vivo in preventing atherosclerosis by inhibiting LDL oxidation in the artery wall.

Evaluation of an enzyme linked immunosorbent assay for the determination of free thyroxine in canine plasma samples assisted by data on biological variation

The purpose of the present study was to evaluate a commercially available enzyme linked immunosorbent assay (ELISA) for the determination of the free thyroxine (FT4) concentration in canine plasma samples. The test kit Enzymun-Test (Boehringer Mannheim) for determination of FT4 concentrations in human serum and plasma was used in connection with the analyzer Enzymun-Test(Boehringer Mannheim) System ES-33 by following the assay protocol suggested by the manufacturer. To assist in the evaluation of the ELISA method, goals for the precision of the assay were established from the inter- and intraindividual coefficients of variation estimated from determination of the plasma FT4 concentration in blood samples collected weekly from 8 healthy dogs for a period of 4 weeks. The intra- and interassay coefficients of variation ranged from 6% to 13%, the proposed goals for the precision ranging between 10% and 15%. The detection limit of the assay was 2 pmol/l which is well below the FT4 concentration commonly observed in plasma from dogs, and the FT4 concentrations determined in plasma from healthy dogs were comparable to those reported in the literature. Hence, the ELISA method evaluated in this study offers a precise and accurate measurement of the FT4 concentration in canine plasma samples, the inter- and intraassay precision comparing favorably to the proposed specifications for assay precision using estimates of the inter- and intraindividual coefficients of variation.

Improved formulae for the judgement of intrathecally produced IgA and IgM in the presence of blood CSF barrier damage

In order to discriminate between transsudated and intrathecally produced IgA and IgM in patients with blood cerebrospinal fluid (CSF) barrier (BCB) damage, we developed extended indices (IgA-EI and IgM-EI) for these immunoglobulins according to the general formula for extended index of a component X in CSF: X-EI = (CSF-X/serum-X)/(CSF-albumin/serum-albumin)a where a is a parameter specific for X. For IgA parameter a was found to be 1.15 and for IgM 1.9. A preliminary evaluation of IgA-EI and IgM-EI indicated lower false positive rates as compared to CSF IgA and IgM concentrations as well as 'conventional' IgA and IgM indices in cases with BCB damage, and essentially the same rates as for the hyperbolic formulae of Reiber and Felgenhauer. The importance of reliable sampling and analytical technique for IgM in CSF is discussed.

Role of 1,25-dihydroxyvitamin D3 in the generation of the acute-phase response in rats with talc-induced granulomatosis

Subcutaneous injection of nonspecific irritants such as magnesium silicate (talc) provokes granulomatous inflammation in the rat. Part of the acute phase response (APR) in these animals is the loss of trabecular bone at sites distant from the site of inflammation. To assess the possible involvement of vitamin D in the bone loss, we studied the development of the acute phase response in vitamin D-deprived rats. The serum APR provoked by subcutaneous inflammation in rachitic rats consisted of hypozincemia, hypercupremia, increased alkaline phosphatase activity and adrenocorticotropic hormone (ACTH) concentration, and was similar to that in control animals except for the absence of hypoferremia. Control rats with talc-induced subcutaneous inflammation also had splenomegaly and decreased total and mononuclear peripheral blood cell counts, while subcutaneous inflammation did not induce spleen changes in rachitic rats. Subcutaneous inflammation induced the loss of trabecular bone and decreased the osteoblastic cell count in tibial metaphyses in control animals. Rachitic rats had abundant osteoid on trabecular surfaces, and the number of osteoblasts and osteoclasts was comparable to that of the controls. Subcutaneous inflammation did not affect any of the bone parameters in rachitic rats. These results indicate that vitamin D plays an important role in the generation of the acute phase response during inflammation, particularly in the induction of spleen and bone cell changes. The discrepancy of the blood on one hand and bone and spleen indices of the APR on the other, indicate that they may be divergent pathways in the generation of the inflammatory response, some of which may be dependent on vitamin D.

Increase in lactoferrin and elastase alpha-1-proteinase inhibitor complexes but lack of complement activation and IL-6 response following thoracic surgery

Polymorphonuclear neutrophil (PMN) stimulation and degranulation can be mediated by the cytokines and by complement activation. The aim of the present study was to measure TNF alpha, IL-1 alpha, IL-6 and C3d in relation to postoperative increase in lactoferrin and elastase alpha-1-proteinase inhibitor (E alpha-1-PI) levels. Eleven patients undergoing thoracic surgery took part in the study. Blood leucocytes, E alpha-1-PI, lactoferrin and C3d were measured preoperatively, at the end of surgery and postoperatively, at 4 h and on day 1, 2, 3 and 5. TNF alpha, IL-1 alpha and IL-6 were measured preoperatively, at the end of surgery and postoperatively, at 4 h, and on days 1 and 5. The leucocyte count, lactoferrin and E alpha-1-PI levels increased significantly postoperatively (P < 0.01). There was no significant change in C3d values. Plasma IL-6 levels were unchanged in the postoperative period. Plasma TNF alpha and IL-1 alpha were detectable at low levels in only two and four patients, respectively.

CONCLUSION

The postoperative increase in blood levels of PMN lactoferrin and E alpha-1-PI complexes observed in the present study was not accompanied by complement activation, or increased blood levels of IL-6.

Oligoclonal IgG in cerebrospinal fluid detected by isoelectric focusing using PhastSystem

Identification of oligoclonal immunoglobulin G (IgG) in cerebrospinal fluid (CSF) is one of the major laboratory signs in multiple sclerosis (MS). Oligoclonal IgG can also be seen in other immunostimulating central nervous system diseases, e.g. meningitis caused by Borrelia spirochetes. A convenient isoelectric focusing (IEF) method combined with polyethyleneglycol-enhanced (PEG) immunofixation and silverstaining using PhastSystem for detection of oligoclonal IgG bands in serum and unconcentrated spinal fluid was developed. Serum and cerebrospinal fluid samples earlier investigated using agarose IEF combined with immunoblotting and avidin-biotin amplified double-antibody peroxidase staining (= A-IEF) were blindly re-analysed using PhastGel IEF 3-9 modified with addition of Pharmalyte 8-10.5 followed by immunofixation and silver staining (= PhastIEF). PhastSystem IEF using PhastGel had the same capability to separate and visualize oligoclonal IgG bands as the conventional agarose IEF. However, PhastIEF was more convenient and less time-consuming than A-IEF. PhastIEF combined with immunofixation and silver staining using application of standardized amounts of IgG for both the serum and CSF samples (40-60 ng IgG/lane is fast, well-standardized and reproducible. The method is sensitive and uses only a minute volume of unconcentrated cerebrospinal fluid for the investigation of CSF IgG pattern.

Copper and zinc body levels in inflammation: an overview of the data obtained from animal and human studies

The development of acute and chronic inflammatory processes induces, in the laboratory animal, a net accumulation of both copper and zinc in many body compartments, the inflamed area included. In rheumatoid arthritis, as well as in animal models, only plasma zinc concentration seems to be significantly correlated with disease severity, while the increase in total plasma copper could be described as an "all or nothing" phenomenon. Moreover, in rheumatoid arthritis, it appears that the disease develops and progresses without being linked to either copper or zinc deficiency conditions. Thus, it seems reasonable to suggest that a rationale for the use of copper and/or zinc in the treatment of inflammatory disorders can only be drawn from the intrinsic pharmacological properties of such trace elements, rather than from the need for their repletion.

Biological variation of acute phase proteins

The analytical, within-subject and between-subject components of variation were estimated for serum albumin, transthyretin, alpha 1-acid glycoprotein, alpha 1-antichymotrypsin, haptoglobin, beta 2-microglobulin and C-reactive protein in a cohort of 19 apparently healthy subjects over 20 weeks. Desirable analytical goals based on biological variation should be able to be met except for serum albumin and beta 2-microglobulin for which methodological improvement is warranted. All proteins showed marked individuality which casts doubt on the utility of conventional population-based reference values as interpretative criteria. The critical differences required for significance of changes in serial results differ markedly from protein to protein and the data presented allow generation of objective criteria for monitoring individuals.

Hypersensitivity pneumonitis resulting from Aspergillus fumigatus in a greenhouse

A 57-y-old female who had cultivated vegetables in a plastic greenhouse developed a case of hypersensitivity pneumonitis from Aspergillus fumigatus. This report exemplifies a potential hazard caused by a thermotolerant fungus, A. fumigatus, in a poorly constructed greenhouse.

Autotransplants with peripheral blood stem cells and clinical results obtained in children: a review

Peripheral blood stem cell transplantation (PBSCT) is increasingly used to support cancer treatment in adults and children. In this review we describe methodological aspects of PBSCT, compare it with autologous bone marrow transplantation (autoBMT), and review the first clinical results obtained with PBSCT in childhood.

Selenium content of sheep's milk and its distribution in protein fractions

The selenium (Se) distribution in sheep's milk is reported. Skim milk was found to contain the major part (98%) of total milk Se. The Se distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk Se is mainly associated with the casein fraction (> 68%). Approximately 11%, 4% and 17% Se is removed by dialysis (molecular mass cut-off 10-12 kDa) from skim milk, casein and whey respectively, indicating a major association of Se with milk proteins. This observation is confirmed through Se analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Se concentrations of the different isolated milk proteins show considerable variations (caseins, 304-750 ng Se/g; whey proteins, 241-806 ng Se/g).

Cyclosporin clinical pharmacokinetics

Cyclosporin is a powerful immunosuppressive drug used in transplantation medicine and to treat autoimmune diseases. It is a lipophilic molecule, with its bioavailability dependent on food, bile and other interacting factors. Cyclosporin is extensively metabolised in the liver by the cytochrome P450 3A system, which is subject to considerable interindividual variation. Distribution of cyclosporin depends not only on physicochemical characteristics, but also on biological carriers such as lipoproteins and erythrocytes in blood. Cyclophilin, a binding protein for cyclosporin, influences distribution of cyclosporin in the body. Despite its lipophilicity, cyclosporin does not appear in the brain. The distribution of metabolites in the body can differ from that of cyclosporin itself. Elimination of the drug is mainly via the bile as metabolites, other routes not being very important. Pharmacokinetic parameters of cyclosporin are highly variable and depend on factors such as age, the physical condition of the patient, type of organ transplant or comedication. Renal side effects of cyclosporin are dose-related, but the influence of the dosage regimen has not been thoroughly investigated. An important factor in the reported variability is the different analytical methods used. Following the recommendations of recent consensus documents to monitor blood concentrations, this source of variability may diminish in the future. Several metabolites are reported as having less immunosuppressive activity than the parent drug. Metabolites with renal side effects have been reported. These and other effects of metabolites have not been clearly defined in the literature, presumably because of the highly variable activity of cyclosporin-metabolising liver enzymes and the paucity of data available on metabolite pharmacokinetics. The therapeutic range and dosage of cyclosporin are therefore highly dependent on many individual parameters in patients. Dosages of less than 5 mg/kg/day, however, rarely cause renal side effects. Further studies to correlate the clinical pharmacokinetics of metabolites with their activity and adverse effects are needed.

Resource package: haemofiltration

Use of haemofiltration is increasing in general intensive therapy units in the United Kingdom, yet few nursing staff working with this technology are trained in renal nursing. They thus need special support while caring for patients being treated with haemofiltration. This package offers a practical working knowledge-base for clinical use. Normal renal physiology is revised, the principles of haemofiltration are discussed, and some areas of concern are examined. Recommendations for practice are given where appropriate. Specific reference is made to the Hospal BSM 22 blood pump, and the Hemospal AN69s filter.

Multivariate analysis of cholesterol distribution for monitoring the risk of coronary heart disease

The screening of people for potential coronary heart disease and the monitoring of subjects considered at risk have been performed for some time by measuring total serum cholesterol and its constituent lipoproteins. However, these measurements vary substantially within subjects, making such assessments imprecise. It has been suggested that greater consistency can be achieved by analysing the joint distribution of the individual lipoproteins or of transformed variables derived from them. In this paper we present the results of a laboratory experiment to investigate these ideas with a view to improving current methods of monitoring patients at risk. Nested, random-effects, multivariate analysis of variance and the log-ratio analysis of compositions are used to include information on all three lipoproteins simultaneously, and ratios of generalized variances are used to assess and compare the different response variables. The multivariate approach is seen to be far superior to the usual methods. Recommendations are made for routine monitoring and the practical implications are discussed.

Regulation of Langerhans cell function by nerves containing calcitonin gene-related peptide

Several observations suggest interactions between the immune and nervous systems. Psoriasis and atopic dermatitis may worsen with anxiety and have been associated with anomalous neuropeptide regulation. Neurotransmitters affect lymphocyte function and lymphoid organs are innervated. Calcitonin gene-related peptide (CGRP) is a neuropeptide and vasodilator that modulates some macrophage functions, including antigen presentation in vitro. CGRP is associated with Langerhans cells (LC) in oesophageal mucosa, particularly during inflammation, is present in epidermal nerves and is associated with Merkel cells. We examined the ability of CGRP to modulate LC antigen-presenting function and asked if CGRP-containing nerves impinge on LC. We report here that CGRP-containing nerve fibres are intimately associated with LC in human epidermis and CGRP is found at the surface of some LC. In three functional assays CGRP inhibited LC antigen presentation. These findings indicate that CGRP may have immunomodulatory effects in vivo and suggest a locus of interaction between the nervous system and immunological function.

Biological variation in glycated proteins

The high degree of individuality in the fructosamine assay has been ascribed to non-specific interferences in the assay. To investigate this, we measured the biological variability of 10 non-diabetic subjects using the fructosamine assay, the new fructosamine plus assay, glycated albumin and glycated total plasma proteins by affinity chromatography. The total variation of the two fructosamine assays was half that of the affinity chromatography assays. This was mainly due to the greater analytical imprecision of the affinity chromatography assays. The resulting high index of heterogeneity for both affinity methods makes it difficult to assess the significance of changes in serial results. The within-subject variation made a small contribution to the total variation for all the assays, and was particularly low for the fructosamine assays. This suggests that any non-specific component makes a constant contribution to the measured fructosamine activity in non-diabetic subjects. The fructosamine assays therefore have significant advantages over the affinity chromatography methods as indices of medium-term glycaemic control.