Effects of clonidine premedication on the pressor response to alpha-adrenergic agonists

It has been suggested that postjunctional alpha 1-adrenoceptor mediated vasoconstriction is enhanced by clonidine. We have examined in humans if the pressor responses to noradrenaline and phenylephrine are enhanced by clonidine premedication. Seventy-seven patients were allocated randomly to either clonidine (n = 38) or control (n = 39) groups. Patients in the clonidine group received approximately 5 micrograms kg-1 with famotidine 20 mg, while the control group received famotidine 20 mg alone orally, 90 min before induction of general anaesthesia with thiamylal. In all patients the lungs were ventilated mechanically via tracheal tubes and anaesthesia maintained with 1% end-tidal enflurane and 67% nitrous oxide in oxygen. When a stable haemodynamic state was obtained, either noradrenaline 0.5 microgram kg-1 (n = 40) or phenylephrine 2 micrograms kg-1 (n = 37) was administered randomly i.v. as a bolus, while arterial pressure and heart rate were measured noninvasively at 1-min intervals for 10 min. Although noradrenaline caused significantly greater increases in mean arterial pressure (MAP) in the clonidine group (from 2 to 4 min after i.v. injection) compared with the control group, there were no significant differences in the mean maximal increment in MAP or area under the MAP curve between the two groups. However, i.v. phenylephrine produced a significantly greater increase in MAP from 2 to 7 min (P < 0.05), and greater mean maximal increase in MAP from the baseline value (21 (9) vs 14 (7) mm Hg; P < 0.05) in the clonidine than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of antibodies to bovine desmocollin isoforms in certain pemphigus sera

We have shown previously that IgG antibodies in certain pemphigus sera, particularly endemic Brazilian pemphigus foliaceus (BPF) sera, react with bovine desmocollins (Dsc), which are transmembranous glycoproteins of desmosome junctions. Desmocollins occur as three different isoforms (Dsc 1, 2 and 3), all of which are represented in the epidermis. In this study, we examined sera of various pemphigus types by immunoblotting purified bovine desmosomes and bovine Dsc 1, 2 and 3 fusion proteins, expressed in pGEX expression vectors. Six of 15 (40.0%) BPF sera, two of 18 (11.1%) non-endemic pemphigus foliaceus sera, eight of 39 (20.5%) pemphigus vulgaris (PV) sera, and two of 11 (18.2%) normal sera, showed reactivity with Dsc from desmosomes. Experiments with fusion proteins showed that no Dsc isoform was specifically recognized by sera of any individual pemphigus type. Our results indicate that the pathogenesis of pemphigus might be more complex than previously believed.

A case of deoxycorticosterone-producing adrenal adenoma

A 29-year-old woman with deoxycorticosterone (DOC)-producing adrenocortical adenoma had hypertension and hypokalemia but without Cushingoid features. Plasma renin activity and the aldosterone concentration were low, while the DOC concentration was high (6.10-10.3 ng/ml; normal range 0.03-0.33). Plasma cortisol, androgens, and estrogens as well as urinary 17-OHCS and 17-KS were within normal limits. Furosemide administration and two hours upright posture resulted in a 3-fold increase in plasma DOC, but the administration of ACTH, dexamethasone, or angiotensin III had no effect on plasma DOC. Following resection of a right adrenal tumor weighing 70 g, the hypertension and hypokalemia disappeared. DOC content in the tumor was high. On light microscopic examination, the tumor was encapsulated, composed of cells with clear cytoplasm and large nuclei and there were extensive areas of fibrosis and infiltration of lymphocytes. According to Weiss's criteria, the tumor was considered to be an adrenocortical adenoma. Immunohistochemically, P450scc, 3 beta HSD, P450C21 and P45011 beta were positive with heterogeneity of intra-tumoral expression. No immunoreactivity for P45017 alpha in this adenoma was detected. This is different from a previous report in which a relatively small number of cells in DOC-secreting adrenocortical carcinoma were positive for P45017 alpha.

Untreated Graves' disease patients without clinical ophthalmopathy demonstrate a high frequency of extraocular muscle (EOM) enlargement by magnetic resonance

12 of 17, a significant frequency (71%), of untreated Graves' disease patients with no clinical ophthalmopathy showed extraocular muscle (EOM) enlargement by Magnetic Resonance Imaging (MRI). Enlargement was bilateral in 41% and unilateral in 29% in these patients. Apparent enlargements of EOM were also detected, by MRI, in all of 11 Graves' disease patients with clinical ophthalmopathy, bilateral in 73% and unilateral in 27% of patients in this group. Both group showed the inferior rectus muscle as the most frequently involved (56% and 77% respectively). In 16 patients without autoimmune thyroid disorders or ophthalmopathy who served as normal controls, only 2 of these patients (12%) demonstrated mild EOM enlargement. The severity and patterns of EOM enlargement revealed no correlation with abnormalities in serum thyroid function tests or serum thyroidal autoantibodies. In conclusion, a high frequency of Graves' disease patients without clinical eye signs or symptoms harbor EOM abnormalities, as demonstrated by MRI. This suggests that present clinical examination methods are insufficient to diagnose varying degrees of ophthalmopathy in patients with autoimmune thyroid disorders who do not initially present with clinical ophthalmopathy.

Multiple abdominal telangiectases and lymphangiectases. A limited form of Osler-Weber-Rendu disease?

We describe a 23-year-old man with protein-losing enteropathy, iron deficiency anemia, and recurrent gastrointestinal bleeding. The patient eventually developed disseminated intravascular coagulation, portal vein thrombosis, and extensive small bowel infarction. The autopsy showed multiple telangiectases in the intestines, mesentery, liver, gallbladder, renal pelves, and diaphragm. In addition, lymphangiectases were found in the retroperitoneal space, intestines, and liver. These lesions appeared to have been the cause of the gastrointestinal bleeding and the protein-losing enteropathy. The case most likely represents Osler-Weber-Rendu disease without the usual manifestations in the skin and oral-nasal cavities.

The addition of epinephrine enhances postoperative analgesia by intrathecal morphine

To investigate whether the addition of epinephrine would enhance postoperative pain relief by intrathecal morphine, we studied 36 patients scheduled to have spinal anesthesia for gynecologic surgery. Patients were randomly allocated to one of three groups: the first received epinephrine 0.12 mg, morphine 0.2 mg, and hyperbaric tetracaine 12 mg intrathecally (EMT group, n = 11); the second received morphine 0.2 mg and hyperbaric tetracaine 12 mg intrathecally (MT group, n = 13); and the third received epinephrine 0.12 mg and hyperbaric tetracaine 12 mg intrathecally (ET group, n = 12). The time to the first request for supplemental analgesics was longest (2182 +/- 251 min, mean +/- SEM) and the injection number of supplemental analgesics was least in the EMT group (P < 0.05). The percentage of patients who received supplemental analgesics in the EMT group (45.5%) was less than the other two groups (P < 0.05). Six patients in the EMT group and one in the MT group needed no additional analgesics during 48 h (P < 0.05 versus the MT and ET groups). The visual analog scale (VAS) pain score was larger in the ET group than the EMT group (P < 0.05), but was similar in the EMT and MT groups. There were no differences among groups in the incidence of nausea and pruritus. Our data show that the addition of epinephrine enhances postoperative analgesia by intrathecal morphine without increasing the incidence of adverse effects as compared with intrathecal morphine alone.

Phosphorylation of proteasome substrate by a protein kinase associated with the 26 S proteasome is linked to the ATP-dependent proteolysis of the 26 S proteasome

A protein kinase phosphorylating the 45-kDa proteasome subunit was co-purified with the 26 S proteasome from the porcine heart. This kinase appears to be associated with the 26 S proteasome, since the kinase activity was co-eluted with the 26 S proteasome on Superose 6 FPLC and immunoprecipitated with anti-20 S proteasome antibody. This kinase also phosphorylated the casein. Furthermore, the phosphorylated casein was more efficiently hydrolyzed by the 26 S proteasome than the dephosphorylated casein without ATP. Inhibition patterns of kinase inhibitors against the 45 kDa subunit and casein were well in accord with the inhibition pattern against the ATP-dependent proteolysis of the 26 S proteasome, suggesting that the phosphorylation of casein by a protein kinase associated with the 26 S proteasome is linked to the ATP-dependent proteolysis of the 26 S proteasome.

Anatomical distribution and postnatal changes in endogenous free D-aspartate and D-serine in rat brain and periphery

We have investigated the anatomical distribution and postnatal development of D-aspartate and D-serine in the rat brain and periphery using HPLC techniques. D-Serine was confined predominantly to the brain throughout postnatal life. At birth, a substantial quantity of D-serine was observed throughout the brain areas. The cerebral D-serine content increased from birth to postnatal week (PW) 3 and remained constant thereafter, whereas the cerebellar D-serine content peaked at PW1. In contrast, the transient emergence of D-aspartate was found in almost all brain and peripheral organs. A substantial quantity of D-aspartate was also seen in all brain areas at birth, whereas the D-aspartate content in the cerebrum and cerebellum decreased dramatically by PW1 and 7 respectively. Further, the D-aspartate content and the ratio of D-aspartate to total aspartate were highest in the adrenal at PW3 (608 +/- 70 nmol/g, 45.9%) and in the testis at PW14 (221 +/- 7 nmol/g, 57.8%) respectively. Because D-serine potentiates N-methyl-D-aspartate receptor-mediated transmission through the strychnine-insensitive glycine site and because D-serine exhibits an N-methyl-D-aspartate receptor-related distribution and development, D-serine may be a tenable candidate for an intrinsic ligand for the glycine site. In contrast, because the periods of maximal emergence of D-aspartate in the brain and periphery occur during critical periods of morphological and functional maturation of organs, D-aspartate could participate in the regulation of these developmental processes of organs.

Restricted usage of T cell receptor V alpha-V beta genes in infiltrating cells in the hearts of patients with acute myocarditis and dilated cardiomyopathy

Prolonged myocardial cell damage initiated by acute myocarditis is thought to be one of the most important etiology of dilated cardiomyopathy. To investigate the immunological mechanisms involved in the pathogenesis of dilated cardiomyopathy, we analyzed the phenotypes of infiltrating cells and examined the expression of perforin in infiltrating cells in the hearts of patients with dilated cardiomyopathy as well as acute myocarditis. We also examined the expression of HLA and intercellular adhesion molecule-1 (ICAM-1) in myocardial tissue of these patients. Furthermore, to evaluate the antigen specificity of infiltrating T cells and persistence of viral genomes in the myocardial tissue, we analyzed the expression of T cell receptor (TCR) V alpha and V beta genes as well as enterovirus genomes by PCR. We found infiltration of perforin-expressing killer cells and enhanced expression of HLA class I and ICAM-1 in the myocardial tissue. We also found that the repertoires of TCR V alpha as well as V beta gene transcripts were restricted, indicating that a specific antigen in the hearts was targeted. Because no enterovirus genomes were detected in all patients, it is strongly suggested that a cell-mediated autoimmune mechanism triggered by virus infection may play a critical role in the pathogenesis of dilated cardiomyopathy. However, we could not exclude the possibility that viruses other than enteroviruses could be pathogenic in these patients.

Conformational epitopes of pemphigus antigens (Dsg1 and Dsg3) are calcium dependent and glycosylation independent

The target molecule of pemphigus autoantibodies is a transmembrane desmosomal component, desmoglein 3 (Dsg3) in pemphigus vulgaris (PV) and Dsg1 in pemphigus foliaceus (PF). In this study, we examined the effects of calcium and glycosylation on the anti-genicity of the pemphigus antigens and on the generation of conformational epitopes. We used recombinant baculovirus proteins, PVIg and PFIg, which are considered to reflect accurately the native conformation of the extracellular domain of their respective proteins Dsg3 and Dsg1. These baculoproteins could immunoadsorb heterogeneous autoantibodies from the corresponding sera of PV and PF patients, completely blocking indirect immunofluorescence staining of normal human skin. Chelating calcium from the solution containing the baculoproteins using ethylenediaminetetraacetic acid (EDTA) or ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) abolished immunoadsorption by both PVIg and PFIg; however, immunoadsorption by the baculoproteins was restored after dialysis against 1 mM calcium. Nonglycosylated forms of both baculoproteins produced in the presence of tunicamycin retained their immunoadsorptive ability. Furthermore, immunoadsorption by the baculo-proteins was prevented irreversibly by treatment with low pH, high pH, and boiling, but not with the non-ionic detergent Nonidet P-40. These findings indicate that formation of the conformational epitopes on the pemphigus antigens is dependent on calcium but independent of glycosylation, and provide direct evidence that calcium plays an important role in determining the antigenic properties of the pemphigus antigens.

Nonisotopic receptor assay for benzodiazepine drugs using time-resolved fluorometry

A nonisotopic receptor assay for benzodiazepine drugs using a time-resolved fluorometric technique is described. A novel europium chelate-labeled benzodiazepine (Eu-1012-S) was prepared as a probe ligand for the binding assay based on the competitive inhibition of Eu-1012-S binding by benzodiazepine drugs to their receptors. In this system, the degree of the inhibition was proportional to the affinity of drugs for the receptor. Background fluorescence did not interfere with the measurement, due to the long-lifetime fluorescence of Eu-1012-S. The proposed nonisotopic assay may provide an alternative to radioreceptor assays of benzodiazepines in biological systems and could also be used to screen new benzodiazepine-like compounds from nature.

Pemphigus vulgaris and pemphigus foliaceus sera show an inversely graded binding pattern to extracellular regions of desmosomes in different layers of human epidermis

We analyzed the location of binding sites for pemphigus vulgaris (PV) antigen and pemphigus foliaceus (PF) antigen in the human epidermis using serum samples obtained from three patients with PV and three patients with PF. Confocal laser scanning microscopy, immunofluorescent examination of ultrathin cryosections, and immunoperoxidase electron microscopy demonstrated discontinuous dots along the epidermal cell surfaces. Immunogold electron microscopy of ultrathin cryosections showed specific binding of PV and PF autoantibodies only to desmosomes. Post-embedding immunogold electron microscopy using cryofixation and cryosubstitution enabled the whole depth of the epidermis to be examined and the binding of PV and PF autoantibodies to be quantitated by counting gold particles. Both PV and PF autoantibodies bound to all desmosomes in the epidermis, but not to the surface of the non-desmosomal keratinocytes. The majority of auto-antibody binding occurred in the extracellular domain (PV, 62%; PF, 69%). The statistical analysis of two-way analysis of variance regarding the number of gold particles labeling a single desmosome confirmed a significant interaction between subtypes of pemphigus (PV and PF) and the different epidermal cell layers (p < 0.044). The results indicate that the number of gold particles bound to individual desmosomes with PV sera was significantly higher in the lower epidermis than in the upper epidermis, and that of PF sera showed reciprocal pattern. This inversely graded binding pattern suggests heterogeneity of the composition of the desmosomes, which may explain the differences in level of acantholysis between PV and PF.

Epidermal melanocytes in normal and tyrosinase-negative oculocutaneous albinism fetuses

In tyrosinase-negative (type IA) oculocutaneous albinism (tyr(-) OCA) fetuses the development of melanocytes has not been fully elucidated. We analysed the distribution of melanocytes in skin samples from a fetus with tyr(-) OCA and from four normal fetuses. Skin samples obtained from 12 different body sites of each fetus were examined by transmission electron microscopy, an electron microscopic DOPA reaction test and immunohistochemistry. No S100 protein-positive cells were detected in any sample. There were fewer HMB-45-positive melanocytes in the skin of the tyr(-) OCA fetus than in the skin of normal fetuses from all body sites sampled. The greatest number of HMB-45-positive melanocytes was present in samples from the scalp of the normal fetuses and in those from the lower limbs of the tyr(-) OCA fetus. Very few melanocytes were detected immunohistochemically in samples from the soles and palms, though their presence was confirmed by transmission electron microscopy. The electron microscopic DOPA reaction test enhanced the melanization of melanocytes in samples from the normal fetuses but not in those from the tyr(-) OCA fetus. Postembedding immunogold electron microscopy using the HMB-45 antibody revealed that the HMB-45 antigen was localized mainly on stages I and II melanosomes. The presence of epidermal melanocytes in samples from all fetal body areas obtained at 17-21 weeks of gestation justifies the use of the electron microscopic DOPA reaction test in the prenatal diagnosis of tyr(-) OCA.

Two patients with unusual skin lesions and circulating antikeratinocyte cell surface antibodies: detection of antibodies to the intracellular domain of the pemphigus foliaceus antigen (desmoglein) by studies using fusion proteins

We report two patients with unusual skin lesions, who had antikeratinocyte cell surface IgG autoantibodies in their sera. Immunoblot analysis of both a human epidermal extract and a bovine desmosome preparation revealed that the sera of both patients reacted exclusively with the 160-kDa pemphigus foliaceus antigen (desmoglein). We further investigated the antigen molecule using bacterial fusion proteins produced by using bovine desmoglein cDNA, and found that both the sera reacted strongly and exclusively with the intracellular domain of the desmoglein. These results suggest that production of antidesmoglein autoantibodies in the present cases may be an epiphenomenon associated with damage to the keratinocyte cell membrane.

Functional comparison of D-serine and glycine in rodents: the effect on cloned NMDA receptors and the extracellular concentration

We compared the activity of free D-Ser on the potentiation of cloned NMDA receptors with that of Gly by using a Xenopus oocyte expression system. The extracellular concentration of free D-Ser and Gly was further studied by means of microdialysis. The ED50 values of D-Ser were three to four times lower than those of Gly in any combination of epsilon 1, epsilon 2, epsilon 3, or epsilon 4 and zeta 1. Site-directed mutagenesis of zeta 1 subunits revealed that some aromatic residues necessary for the action of Gly affected the ED50 value of D-Ser. This result showed that the residues play crucial roles in the action of D-Ser. In vivo microdialysis of rodent brain revealed that the extracellular concentration of free D-Ser in the frontal cortex (6.5 microM) was high enough to saturate the Gly site on the NMDA receptor, but that in the cerebellum was not. These findings suggest that D-Ser is a candidate of the endogenous potentiator of the NMDA receptor in the rodent frontal cortex.

An adult diagnosed as hyper-IgM immunodeficiency syndrome

A 27-year-old male who visited our hospital because of pneumonia was diagnosed as hyper-IgM immunodeficiency syndrome. His serum IgM level was markedly elevated, while the serum level of IgD was normal with a markedly decreased level of serum IgG and IgA. The proportion of T and B cells of peripheral blood lymphocytes was normal. However, B cells bearing surface IgG or IgA were not detectable by immunofluorescence technique. There was a consanguineous marriage in his family, suggesting that his disorder was caused by a genetic abnormality such as X-linked recessive and also autosomal recessive inheritance, although further study is necessary. CD40 ligand cDNA did not appear to contain any abnormal changes within the coding region.

Differential localization of atrial natriuretic peptide and skeletal alpha-actin messenger RNAs in left ventricular myocytes of patients with dilated cardiomyopathy

OBJECTIVES

This study was designed to determine whether atrial natriuretic peptide and skeletal alpha-actin messenger RNAs (mRNAs) are co-localized in ventricular myocytes of patients with dilated cardiomyopathy.

BACKGROUND

Atrial natriuretic peptide and skeletal alpha-actin are known as augmented genes with cardiac hypertrophy. However, the expression and localization of both genes in chronic failing heart remain unclear.

METHODS

Left ventricular biopsy specimens were obtained from 14 patients with dilated cardiomyopathy. Atrial natriuretic peptide and skeletal alpha-actin mRNAs were detected by in situ hybridization with specific sulfur-35 uridine triphosphate-labeled RNA probes in the serial sections.

RESULTS

Atrial natriuretic peptide mRNA was detected in 10 patients, and intense signals were localized in the myocytes located in the subendocardium and around the interstitial fibrous area. By contrast, skeletal alpha-actin mRNA was homogeneously detected in all myocytes in seven patients. By left ventriculography, patients with skeletal alpha-actin-positive findings had a lower ejection fraction (37.1 +/- 6.0%) than those with negative findings (46.3 +/- 5.8%, p < 0.05), but atrial natriuretic peptide mRNA expression was not related to left ventricular function.

CONCLUSIONS

These results indicate that the expression of atrial natriuretic peptide and skeletal alpha-actin mRNAs are not always co-localized in the left ventricle of patients with dilated cardiomyopathy and suggest that the mechanisms of the regulation of these two genes in the chronic failing heart are different.