Skin infection caused by Mycobacterium avium

A patient with skin infection due to Mycobacterium avium is reported. A 9-year-old female had 10 subcutaneous nodules and two ulcers on the abdomen and legs. She had no medical history of systemic disease, skin disease or immunosuppressive therapy. Cultures of a biopsy specimen and of aspirated seropurulent fluid in nodules showed acid-fast bacteria, identified as M. avium by the DNA-DNA hybridization method. We treated her with a combination of surgery and the antibiotics, cycloserine, isoniazid and clarithromycin.

Basic fibroblast growth factor inhibits basal and transforming growth factor-beta induced collagen alpha 2(I) gene expression in scleroderma and normal fibroblasts

OBJECTIVE

Studies have shown that scleroderma (systemic sclerosis, SSc) and normal fibroblasts respond differently to basic fibroblast growth factor (bFGF), SSc fibroblasts being less responsive than normal fibroblasts in mitogenic assays in vitro, bFGF also stimulates the expression of platelet derived growth factor-alpha (PDGF-alpha) receptors in normal fibroblasts, but not in SSc fibroblasts. Conversely, transforming growth factor-beta (TGF-beta) stimulates PDGF-alpha receptor expression in SSc fibroblasts, but not in normal fibroblasts. Since bFGF has been shown to inhibit collagen gene expression in several cell types, we examined responses of SSc and normal fibroblasts to bFGF alone and in combination with TGF-beta with regard to collagen alpha 2(I) (COL1A2) expression.

METHODS

Fibroblasts were obtained by skin biopsy from affected areas of patients with diffuse cutaneous SSc and from healthy donors and propagated in vitro. The effects of bFGF and TGF-beta on the COL1A2 mRNA expression levels in SSc and healthy fibroblasts were analyzed by Northern blot. The effects of bFGF on the COL1A2 promoter activities in both cell types were analyzed by transient transfection assays. The effects of bFGF and TGF-beta on collagen protein synthesis were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and fluorography.

RESULTS

While bFGF diminished COL1A2 mRNA in both SSc and normal cells, COL1A2 mRNA quantities in the SSc fibroblasts were not depressed to the levels expressed by normal controls. As anticipated, TGF-beta strongly induced COL1A2 mRNA levels in normal fibroblasts, and to a lesser degree in SSc fibroblasts. When cells were incubated with both TGF-beta and bFGF, the stimulatory effect of TGF-beta was completely suppressed in both cell types. bFGF decreased COL1A2 promoter activity in both cell types, suggesting that COL1A2 inhibition by bFGF occurs at least partially at the transcriptional level. The effects of bFGF and TGF-beta on the collagen protein synthesis correlated well with mRNA data, in that TGF-beta stimulated, while bFGF strongly inhibited, collagen synthesis.

CONCLUSION

bFGF is a potent inhibitor of basal and TGF-beta stimulated collagen expression in human fibroblasts, and this effect is not different between SSc and healthy fibroblasts.

Detection of scleroderma with capillaroscopic abnormalities of nailfolds

BACKGROUND

Systemic scleroderma is a problem in Gifu Prefecture, Japan.

METHODS

Three hundred and thirty-two men and 731 women over 30 years of age, who attended the residents' health examination in K town of Gifu Prefecture (population 4835 persons over 30 years of age) had a dermatologic examination. Antinuclear antibody was determined in 85 persons (14 men, 71 women; age 30 to 72 years) who had Raynaud's phenomenon or various clinical features related to systemic scleroderma. Of these 85 persons, 19 agreed to a capillaroscopic examination and of these, 16 showed some capillaroscopic abnormalities. Biopsy specimens of three women among these 16 individuals with capillaroscopic abnormalities were examined also histopathologically.

RESULTS

All samples taken from the forearm skins showed thick and packed bundles of collagen with hyalinization and thickened small blood vessels in the dermis, similar to histopathologic features of systemic scleroderma, although all these women had only a sausage-like swelling of the fingers and a shortened frenulum of the tongue. These results suggest that the prevalence of systemic scleroderma can be estimated to affect more than 0.38% of the population in this town.

CONCLUSIONS

Manual skills and vibration exposure may be associated with systemic scleroderma.

Transcytosis of lipid microspheres by human endothelial cells

Human endothelial cells were cultivated on microporous membranes mimicking the luminal and basal spaces of blood vessels. When fluorescence-labeled lipid microspheres (LM) were added to the upper chambers of the model cultures, confluent monolayers of endothelial cells transported considerable levels of fluorescence to lower chambers. The transport was time dependent and was diminished by the addition of cytochalasin B. The uptake of LM into the endothelial cytoplasm was confirmed by electron microscopy and laser scanning confocal imaging. The amounts of fluorescence in the lower chamber were reduced when the endothelial cell layer was fixed with formaldehyde. These observations suggest that endothelial cells can transport LM by transcytosis. Endothelial cells seem to carry the LM without processing, since only minimal amounts of free fluorescence were detected even after longer cultivation periods. The fluorescence in the lower chambers of cell cultures treated with interleukin 1 beta was 3.7-fold higher than that of untreated cells; interleukin 2 and tumor necrosis factor alpha treatments had no discernible effect on LM transport. The interleukin 1 beta induced increase of transcytosis in endothelial cells would explain why LM preferentially accumulate in inflammatory tissues.

Plasma concentration of human adrenomedullin in patients on hemodialysis

To investigate a possible pathophysiological role of human adrenomedullin (AM), we measured the plasma concentration of immunoreactive-AM (ir-AM) in 38 patients with end-stage renal disease (ESRD) on hemodialysis (HD) and 38 healthy subjects (age and sex matched). In addition, plasma ir-AM was characterized by a reverse-phase high performance liquid chromatography. The mean value (+/- SEM) of plasma AM in the patients before HD (10.1 +/- 0.67 fmol/ml) was markedly higher than that in the control group (2.9 +/- 0.13 fmol/ml, p < 0.001), but plasma AM levels were not altered by HD. There was a significant correlation between plasma AM levels and mean blood pressure (MBP) in a group of subjects including both patients before HD and healthy subjects (p < 0.01). In chromatographic study, the major peak of ir-AM in the plasma from patients on HD, as well as healthy subjects, emerged at an elution time identical to that of synthetic AM, indicating that the active form of AM was present in the circulating blood. The secretion of AM seemed to be increased in response to the conditions elicited by ESRD such as hypervolemia and/or hypertension, and reduced renal excretion of the peptide may also contribute to its high plasma level.

Plasma adrenomedullin in patients with primary aldosteronism

Adrenomedullin (AM) is a novel hypotensive peptide originally isolated from the pheochromocytoma tissue of humans. To examine the pathophysiological role of AM in primary aldosteronism (PA), the plasma concentration of AM in patients with PA was measured with a specific radioimmunoassay and compared to that in age- and sex-matched healthy normotensive subjects. In addition, the concentrations of AM as well as catecholamines in the plasma from both the adrenal vein and the inferior vena cava (IVC) were measured to determine whether or not the circulating AM in these PA patients is supplied from the adrenal medulla, which contains a much higher concentration of AM than any other human tissue does. The plasma concentration of AM in the PA patients (4.57 +/- 0.32 fmol/mL, n = 6) was significantly (P < .01) higher than that in the healthy subjects (3.06 +/- 0.20 fmol/mL, n = 12). A significant positive correlation (r = 0.62, P < .01) was observed between the mean blood pressure and the plasma AM level. The AM concentration in plasma from the adrenal vein was almost the same level as that from the IVC although the concentrations of both epinephrine and norepinephrine in the adrenal vein were much higher than those in the IVC. Therefore, it seems unlikely that the plasma AM in the PA patients is mainly supplied from the adrenal medulla. Judging from the potent hypotensive activity of AM, the present findings suggest that AM participates in defense mechanisms acting against the elevation of blood pressure in the patients with PA.

Distribution and characterization of immunoreactive adrenomedullin in porcine tissue, and isolation of adrenomedullin [26-52] and adrenomedullin [34-52] from porcine duodenum

Using a sensitive radioimmunoassay which recognizes the carboxy-terminal region of porcine adrenomedullin, the distribution of immunoreactive adrenomedullin was widely distributed in porcine tissue, and its concentration was highest in adrenal medulla (126 +/- 32 fmol/mg wet tissue; mean +/- SD). Relatively high concentrations of immunoreactive adrenomedullin were found in the right atrium, lung, duodenum, and pituitary gland. The molecular form of immunoreactive adrenomedullin in all porcine tissues was found to be almost wholly porcine adrenomedullin itself by analysis with reverse-phase high-performance liquid chromatography coupled with radioimmunoassay. Minor molecular forms of immunoreactive adrenomedullin were found in the porcine duodenum. These were isolated and identified as adrenomedullin [26-52] and adrenomedullin [34-52].

Haemodynamic responses to rat adrenomedullin in anaesthetized spontaneously hypertensive rats

1. The haemodynamic effects of rat adrenomedullin (AM), a novel hypotensive peptide, were examined in anesthetized 16-18 week old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). 2. An intravenous injection of rat AM dose-dependently reduced the mean blood pressure (MBP) with a concomitant fall in total peripheral resistance index (TPRI) and an increase in cardiac index (CI) in both strains of rats. Percent changes in MBP, TPRI and CI were not different between SHR and WKY. 3. The plasma half-life of rat AM in SHR was similar to that in WKY when it was administered at the dose of 1.0 nmol/kg. 4. These findings indicate that AM has a potent vasorelaxant activity in both SHR and WKY. The haemodynamic responsiveness to exogenous AM and its pharmacokinetics in SHR were comparable with those in WKY.

Human proadrenomedullin N-terminal 20 peptide in pheochromocytoma and normal adrenal medulla

Proadrenomedullin N-terminal 20 peptide (PAMP) is a novel hypotensive peptide found in adrenomedullin precursor. Using a radioimmunoassay for human PAMP, we purified immunoreactive PAMP (ir-PAMP) from human pheochromocytoma and determined its complete amino acid sequence. The major component of PAMP-like immunoreactivity was found to be PAMP [1-20] NH2 with an amino acid sequence identical to that of the deduced amino acid sequence by cDNA analysis. Both ir-PAMP and ir-adrenomedullin were found to be abundant in normal adrenal medulla as well as pheochromocytoma tissue arising from adrenal medulla, and there was a significantly (p < 0.05) positive correlation between ir-adrenomedullin and ir-PAMP concentrations in these tissues. However, the PAMP/adrenomedullin ratio in pheochromocytoma tissues (0.197 +/- 0.013) was significantly (p < 0.005) lower than that in adrenal medullae (0.384 +/- 0.041). The present data indicate that PAMP is biosynthesized from adrenomedullin precursor, but the biosynthesis or metabolism of PAMP in pheochromocytoma may be different from that of normal adrenal medulla.

Immunohistochemical identification of adrenomedullin in human, rat, and porcine tissue

The histological localization was investigated of adrenomedullin (AM), a novel vasorelaxant peptide originally isolated from human pheochromocytoma. The immunohistological distribution was examined of AM in human, rat, and porcine tissues using a polyclonal antibody to a fragment comprising C-terminal amino acids 40-52 of human adrenomedullin [AM(40-52)NH2]. Almost all of the human pheochromocytoma and normal adrenal medullary cells of all three species were immunostained and found to be intensely positive for AM. Furthermore, AM-immunoreactive cells were present in the pancreatic islets, gastrointestinal neuroendocrine system, anterior pituitary, and choroid plexus with some degree of interspecies heterogeneity. These findings indicate that AM-immunoreactive cells are widely distributed in the endocrine and neuroendocrine system, suggesting that AM plays some important role in the control of systemic and local circulation and also of humoral secretion.

Different effects of basic fibroblast growth factor and transforming growth factor-beta on the two platelet-derived growth factor receptors' expression in scleroderma and healthy human dermal fibroblasts

Previous studies have demonstrated that platelet-derived growth factor (PDGF) alpha receptor expression is up-regulated by transforming growth factor-beta 1 (TGF-beta 1) in scleroderma dermal fibroblasts, but not in healthy control fibroblasts. We asked whether this selective effect in scleroderma cells was TGF-beta 1-specific or a general response by studying responses to other growth factors. In this study, we compared the expression of alpha and beta PDGF receptor subunits (mRNA and protein levels) in these two cell types in response to basic fibroblast growth factor (bFGF) and TGF-beta 1. bFGF coordinately stimulated mRNA levels of alpha and beta receptor subunits in healthy fibroblasts, but did not change PDGF receptor expression in scleroderma fibroblasts. Conversely, and in agreement with previous observations, TGF-beta 1 induced PDGF alpha receptor expression in scleroderma fibroblasts, but not in healthy fibroblasts. PDGF beta receptor mRNA levels were induced to similar degrees by TGF-beta 1 in both cell types. PDGF alpha receptor protein levels correlated directly with mRNA levels, induced by bFGF only in healthy fibroblasts and by TGF-beta 1 only in scleroderma fibroblasts. However, PDGF beta receptor protein levels were not altered by either growth factor in either cell type. Thus, the activated state of scleroderma fibroblasts does not include receptor-signaling pathways to bFGF. This distinct pattern of expression of PDGF alpha receptors in scleroderma fibroblasts suggests a possible role for the coordinately expressed PDGF AA ligand/alpha receptor system in the development of fibrosis.

Identification and hypotensive activity of proadrenomedullin N-terminal 20 peptide (PAMP)

Proadrenomedullin N-terminal 20 peptide (PAMP) is a candidate for a novel biologically active peptide processed from an adrenomedullin precursor. Using a radioimmunoassay for human PAMP, major and minor immunoreactive PAMPs were purified from porcine adrenal medulla and complete amino acid sequences were determined. The major immunoreactive peptide was PAMP itself with an amidated carboxy terminus. The minor one was determined to be PAMP[5-20]. An intravenous bolus injection of human PAMP in anesthetized rats caused a rapid and strong hypotensive effect in a dose dependent manner. The present data indicate that PAMP is an endogenous biologically active peptide which is processed from adrenomedullin precursor.

Immunoreactive proadrenomedullin N-terminal 20 peptide in human tissue, plasma and urine

Proadrenomedullin N-terminal 20 peptide (PAMP) is a candidate for a novel biologically active peptide processed from proadrenomedullin. This study clearly demonstrates the existence of PAMP in vivo that had been deduced from analysis of cDNA. To identify PAMP in vivo, we established a radioimmunoassay for PAMP and characterized immunoreactivities in human tissue, plasma and urine. Half maximal inhibition of the assay was observed at 10 fmol/tube. A high concentration of immunoreactive PAMP was found in adrenal medulla (18.4 +/- 8.95 fmol/mg, mean +/- S.D.) and pheochromocytoma tissue (12.3 +/- 9.82 fmol/mg) where the concentrations are comparable to that of adrenomedullin. As determined by three different kinds of chromatography, most of the immunoreactive peptide in pheochromocytoma was eluted at a position exactly identical to that of synthetic PAMP. Further, considerable concentration of immunoreactive PAMP was found in human plasma and urine. The present data indicate that PAMP as well as adrenomedullin is processed from an adrenomedullin precursor.

Ca(2+)-dependent cosecretion of adrenomedullin and catecholamines mediated by nicotinic receptors in bovine cultured adrenal medullary cells

Bovine cultured adrenal medullary cells (4 x 10(6)) contained 4266.5 +/- 370.0 fmol of immunoreactive adrenomedullin and 373.4 +/- 32.6 nmol of catecholamines. Nicotinic (but not muscarinic) receptors mediated the Ca(2+)-dependent co-secretion of adrenomedullin and catecholamines, with the molar ratio of adrenomedullin/catecholamines secreted into the medium being equal to the ratio stored in the cells. The concentration-response curve of carbachol for adrenomedullin secretion (EC50 42 microM) was similar to that for catecholamine secretion (EC50 63 microM). Reverse phase HPLC analysis showed that immunoreactive adrenomedullins in the cells and secreted into the medium were both eluted exclusively at the position almost identical to synthetic human adrenomedullin[1-52]NH2.

Immunoreactive adrenomedullin in human plasma

A specific and sensitive radioimmunoassay for adrenomedullin has been developed. Half-maximal inhibition of binding of radioiodinated adrenomedullin was observed at 4 fmol/tube. The radioimmunoassay recognized the entire adrenomedullin molecule and has little crossreactivity with adrenomedullin fragment peptides. Adrenomedullin-like immunoreactivity was found to circulate in human plasma at considerable concentration (3.3 +/- 0.39 fmol/ml). The immunoreactivity of adrenomedullin was eluted at almost the same position as synthetic adrenomedullin on gel-filtration chromatography and reverse-phase high-performance liquid chromatography, suggesting that circulating adrenomedullin recognized by the present radioimmunoassay is identical or very similar to authentic adrenomedullin. Plasma immunoreactive adrenomedullin significantly increased in patients with hypertension, with a progressive rise proportionate to disease severity.

Complete amino acid sequence of porcine adrenomedullin and cloning of cDNA encoding its precursor

Porcine adrenomedullin was isolated from adrenal medulla extract and its amino acid sequence was determined. The peptide is identical to human adrenomedullin with a single replacement of Gly for Asn at position 40. The cDNA clone encoding the porcine adrenomedullin precursor was isolated and sequenced. The precursor for adrenomedullin (preproadrenomedullin) is 188 amino acids in length, including the adrenomedullin sequence, followed by a glycine (the amide donor). In addition to adrenomedullin, proadrenomedullin (proAM) contains a candidate for a unique 20-residue peptide, proAM-N20, whose carboxy-terminus may be amidated. By RNA blot analysis, porcine adrenomedullin mRNA was found to be highly expressed in several porcine tissues including lung and kidney as well as adrenal medulla.

Distribution and characterization of immunoreactive adrenomedullin in human tissue and plasma

A specific and sensitive radioimmunoassay for human adrenomedullin has been developed and distribution and characterization of immunoreactive adrenomedullin in human tissue were investigated. The radioimmunoassay specifically recognizes its carboxyterminal region and half maximal inhibition of binding of radioiodinated adrenomedullin(40-52)NH2 was observed at 11 fmol/tube. Immunoreactive adrenomedullin was abundant in adrenal medulla (47.7 +/- 26.1 fmol/mg, mean +/- S.D.) and was ubiquitously found in all tissue examined. The mean plasma concentration of adrenomedullin in three normal individuals was 17.2 +/- 6.4 pg/ml (mean +/- S.D.). By analysis with reverse-phase high-performance liquid chromatography coupled with the radioimmunoassay, most immunoreactive adrenomedullin in the adrenal medulla, atrium and lung was found to be adrenomedullin(1-52)NH2.

[A case of pulmonary metastasis from colon cancer successfully treated by 5-FU combined with leucovorin and interferon alpha-2a]

A 58-year-old woman with colon cancer, who had received oral 5-FU over 17 months after right hemicolectomy, was diagnosed as having a recurrence of the disease with multiple pulmonary metastasis. She was treated for 5 days with a combination of continuous infusion of 5-FU 600 mg/m2/day, bolus injection of leucovorin (LV) 20 mg/m2/day, and intramuscular injection of interferon (IFN)-alpha-2a (6.0 x 10(6) U/day, repeated every 3 weeks. The chest X-ray after three cycles showed a decrease in size of metastatic lesions by 51%, indicating a partial response. Correspondingly, the serum levels of CEA and CA 19-9 significantly decreased. There were modest but tolerable side effects such as fever, nausea, diarrhea, stomatitis, and alopecia. The patient has been given oral UFT and LV after discharge, and is still alive with continued improvement of pulmonary lesions even 9 months after initial chemotherapy. Although the detailed synergistic mechanism of 5-FU and IFN has yet to be determined, the addition of IFN, as a biochemical modulator distinct from LV, to the combination of 5-FU and LV, appears to further potentiate the therapeutic efficacy and may be useful for advanced colorectal cancer.

Hemodynamic effects of a novel hypotensive peptide, human adrenomedullin, in rats

The hemodynamic effects of human adrenomedullin were investigated in anesthetized Wistar rats. Intravenous administration of adrenomedullin (1.0 nmol/kg) caused a rapid and marked reduction in mean blood pressure associated with a decrease in total peripheral resistance. This reduction in mean blood pressure was closely correlated with the decrease in total peripheral resistance. These findings indicate that human adrenomedullin is a potent vasodilator and may have some role in the regulation of blood pressure.

Adrenomedullin: a novel hypotensive peptide isolated from human pheochromocytoma

A novel hypotensive peptide was discovered in human pheochromocytoma by monitoring the elevating activity of platelet cAMP. Since this peptide is abundant in normal adrenal medulla as well as in pheochromocytoma tissue arising from adrenal medulla, it was designated "adrenomedullin". The peptide, consisting of 52 amino acids, has one intramolecular disulfide bond and shows slight homology with calcitonin gene related peptide. It was found to elicit a potent and long lasting hypotensive effect. The peptide circulates in blood in a considerable concentration, but it was not found in brain. These data suggest that adrenomedullin is a new hormone participating in blood pressure control. Occurrence of adrenomedullin indicates the possible existence of a novel system for circulation control.

Dimeric form of calcitonin gene-related peptide in the porcine thyroid gland

In this study we investigated peptides that increase rat platelet cAMP in porcine thyroid gland. Gel filtration of extracts from porcine thyroid gland showed high and low molecular weight activity. Low molecular weight activity contained peptides, including calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI). We isolated a high molecular weight peptide (M. W. 11,000) showing potent activity able to increase rat platelet cAMP in porcine thyroid gland. The peptide's N-terminal sequence was determined to be Ser-X-Asn-Thr-Ala-Thr- by gas phase sequencer analysis, a sequence identical to that of porcine CGRP. The peptide had CGRP immunoreactivity as well as platelet cAMP elevating activity. By gel filtration HPLC, synthetic human CGRP (M. W. 3790) was eluted in a position corresponding to M. W. 5,500. These results suggest that judging from its high molecular weight the above peptide is a dimeric form of CGRP.

Cutaneous signs (Raynaud's phenomenon, sclerodactylia, and edema of the hands) and hand-arm vibration exposure

Dermatological tests and examinations of the hand(s) were carried out in vibration-exposed and unexposed males. The subjects were 179 chain-saw workers in private forestry companies and 205 local inhabitants who had never used vibrating tools. The prevalences of Raynaud's phenomenon (RP), sclerodactylia, and edema of the hands were estimated in both groups, and associations between these cutaneous signs and vibration exposure were evaluated. The prevalences of RP and edema in the exposed group were 9.5% and 1.7%, respectively, and in the unexposed group, 2.9% and 1.5%, respectively. Sclerodactylia was seen in 31.8% of the chain-saw workers but in only 6.4% of the unexposed individuals. In statistical analyses based on unconditional logistic regression models with adjustment for age, RP was associated with long-term (> or = 20 years) vibration exposure [odds ratio (OR) = 7.06; 95% confidence interval (CI) = 2.51-19.87]. Sclerodactylia was associated with both short- and long-term vibration exposure (OR = 6.54, CI = 3.30-13.36; OR = 7.05; CI = 3.41-14.60, respectively). There were significant dose-response relationships between RP and duration of exposure and between sclerodactylia and duration of exposure. Results of function tests indicated a longer recovery time and a higher vibration threshold for the workers with RP. The presence of sclerodactylia, however, did not have any significant influence on function test results. It is possible to conclude that not only RP but also sclerodactylia could be induced by vibration exposure. However, most cases of sclerodactylia were not so serious as to involve disturbances of peripheral circulatory and nerve function.