Bioactive peptide design based on protein surface epitopes. A cyclic heptapeptide mimics CD4 domain 1 CC' loop and inhibits CD4 biological function

The interaction between CD4 and major histocompatibility complex class II proteins provides a critical co-receptor function for the activation of CD4(+) T cells implicated in the pathogenesis of a number of autoimmune diseases and transplantation responses. A small synthetic cyclic heptapeptide was designed and shown by high resolution NMR spectroscopy to closely mimic the CD4 domain 1 CC' surface loop. This peptide effectively blocked stable CD4-major histocompatibility complex class II interaction, possessed significant immunosuppressive activity in vitro and in vivo, and strongly resisted proteolytic degradation. These results demonstrate the therapeutic potential of this peptide as a novel immunosuppressive agent and suggest a general strategy of drug design by using small conformationally constrained peptide mimics of protein surface epitopes to inhibit protein interactions and biological functions.

Patent ductus arteriosus with combined valvular disease at age 91

This report describes a 91-year-old patient with patent ductus arteriosus (PDA) complicated by combined valvular disease (CVD) (aortic and mitral stenosis, and aortic, mitral, pulmonic and tricuspid regurgitation). This patient seems to be the oldest living female with PDA and CVD hitherto reported in the medical literature. The patient developed several bouts of congestive heart failure which were treated medically. She not only has survived without surgical management, but is still enjoying her life at age 91. The features of PDA in the elderly are reviewed.

Systemic lupus erythmatosus associated with autoimmune hepatitis two cases with novel autoantibodies to transfer RNA-related antigens

Two cases of systemic lupus erythematosus (SLE) with autoimmune hepatitis are reported. Both patients had a mild form of SLE without central nervous system or renal involvement and showed a rapid response to corticosteroid therapy. Neither of them had antibodies to mitochondria, smooth muscle, and liver/kidney microsome-1 related to autoimmune hepatitis. Instead, novel autoantibodies which react with transfer RNA-related antigen were detected. These autoantibodies could be a useful marker for classification of SLE associated with autoimmune hepatitis.

[Two cases of advanced gastric cancer effectively treated with chemotherapy of 5-fluorouracil, cisplatin and cytarabine]

We reported two cases of advanced gastric cancer effectively treated with chemotherapy of 5-fluorouracil (5-FU), cisplatin (CDDP) and cytarabine (Ara-C), 5-FU (300-350 mg/body) was given by continuous intravenous infusion. Ara-C (20-40 mg/body) by continuous infusion and CDDP (15-20 mg/body) were added intravenously for 3-6 days. For case 1, epirubicin (30 mg/body) was also given on the first day of each therapy course. Case 1 was a 62-year-old female who had gastric cancer with liver metastasis, ovarian metastasis and peritonitis carcinomatosa. After 3 courses of the chemotherapy, reduction of ovarian metastasis greater than 75% was observed. The value of CA125 decreased from 6,800 U/ml to 527 U/ml and ascites disappeared. Case 2 was a 54-year-old male who had type 3 advanced gastric cancer with multiple liver metastases. He received 6 courses of the therapy. Both primary and metastatic tumors showed over 50% reduction in tumor size. These suggested that this combination therapy was effective for inoperable advanced gastric cancers.

Evaluation of propolis. I. Evaluation of Brazilian and Chinese propolis by enzymatic and physico-chemical methods

To establish a method of evaluating propolis, the effects of the ethanol and water extracts from various collecting of propolis from different countries and plant sources on hyaluronidase activity were investigated along with their absorption spectra and specific absorbance (E(1%)1 cm value). The relations between the hyaluronidase inhibitory activities of these extracts and their E(1%)1 cm values were also examined, and the following was found: 1) the enzyme inhibitory activities of the ethanol extracts were more potent than those of the water extracts; 2) the enzyme inhibitory activities of the ethanol extracts from Araucaria angustifolia (BERT.) O. KTZE were low compared with those of other ethanol extracts; 3) the enzyme inhibitory activities of all the ethanol extracts correlated excellently with their E(1%)1 cm values, but in the water extracts, they decreased with increase in E(1%)1 cm values; 4) the water extracts of Chinese propolis from Hebei, Jiangsu, Sichuan and Zhejiang Provinces inhibited weakly compared with that from Brazilian and other Chinese propolis; 5) the shapes of absorption bands of the propolis extracts and the E(1%)1 cm values were approximately dependent on the place or the plant source from which propolis was collected. These experimental results indicated that, for the exact evaluation of propolis, the enzymatic method, measuring the hyaluronidase inhibitory activity, was superior to the physicochemical method.

Characteristics of pulmonary artery pressure waveform for differential diagnosis of chronic pulmonary thromboembolism and primary pulmonary hypertension

OBJECTIVES

The accurate diagnosis of chronic pulmonary thromboembolism (CPTE) is a prerequisite for life-saving surgical interventions. To help in the differential diagnosis of CPTE and primary pulmonary hypertension (PPH), we characterized the configuration of the pulmonary artery pressure waveform.

BACKGROUND

Because CPTE predominantly involves the proximal arteries, whereas PPH involves the peripheral arteries, we hypothesized that patients with CPTE would have stiff or high resistance proximal arteries, whereas those affected by PPH would have high resistance peripheral arteries. These differences in the primary lesions would make arterial pulsatility relative to mean pressure larger in CPTE than in PPH.

METHODS

In 34 patients with either CPTE (n = 22) or PPH (n = 12) whose pulmonary systolic pressure was > or = 50 mm Hg, we measured pulmonary artery pressure using a fluid-filled system that included a balloon-tipped flow-directed catheter.

RESULTS

To quantify the magnitude of pulsatility relative to mean pressure, we normalized pulse pressure by mean pressure, hereinafter referred to as fractional pulse pressure (PPf). PPf was markedly higher in CPTE than in PPH (mean [+/-SD] 1.41 +/- 0.20 and 0.80 +/- 0.18, respectively, p < 0.001) and was diagnostic in separating the two groups without overlap. Similarly, the coefficient of variation of pulmonary artery pressure also separated the two groups without overlap (0.45 +/- 0.06 and 0.25 +/- 0.06, respectively, p < 0.001). Fractional time to half the area under the pressure curve separated the two groups reasonably well (0.35 +/- 0.02 and 0.43 +/- 0.03, respectively, p < 0.001).

CONCLUSIONS

The analysis of pulsatility of pulmonary artery pressure is useful in the differential diagnosis of CPTE and PPH.

Xenon contrast CT-CBF measurements in high-intensity foci on T2-weighted MR images in centrum semiovale of asymptomatic individuals

BACKGROUND AND PURPOSE

White matter lesions (WMLs) on T2-weighted MR images occurring in the centrum semiovale of normal individuals are a subject of great clinical interest. We therefore investigated regional cerebral blood flow (rCBF) of the centrum semiovale among neurologically normal individuals.

METHODS

One hundred thirty-five neurologically normal subjects were divided into four grades of WML on the basis of their MR images. rCBF values in the centrum semiovale were measured by xenon contrast CT methods.

RESULTS

Advanced age and associated hypertension were significant risk factors for higher grade WMLs. Centrum semiovale rCBF values on the left side were 24.27 +/- 2.60 mL.100 g-1.min-1 in grade 0, 23.52 +/- 2.78 in grade I, 19.35 +/- 2.81 in grade II, 15.82 +/- 2.05 in grade III, and 11.31 +/- 2.56 in grade IV. Differences were significant between grades (P < .005 between grade 0 and grades II, III, and IV; between grade II and grades III and IV; and between grades III and IV). Patients with hypertension had lower rCBF values than those without in grades 0, I, II, and III, with significant difference in grade I (P < .005). Age-matched studies between patients 61 to 70 years old confirmed a significant difference between WML grades.

CONCLUSIONS

WMLs in centrum semiovale are associated with greater age, hypertension, and reduced rCBF values.

Bile acid metabolism in young-old parabiotic rats

Serum cholesterol, triglyceride and phospholipid levels, liver cholesterol concentration, bile flow, biliary cholesterol, phospholipid and bile acid secretion rates, fecal sterol and bile acid levels and their bile acid compositions were examined in young-old parabiotic rats and compared with those in young and old control rats and young-young parabiotic rats. Bile acid composition was expressed in terms of the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio. Body weight (BW) gain decreased after parabiosis especially in old rats, but the liver weight (g/100 g BW), diet-intake, feces dry weight, liver cholesterol concentration and fecal sterol level were almost the same in all the groups. The biliary bile acid secretion rate was higher and the fecal bile acid level was lower in old rats than those in young rats but both the levels became comparable with those in young rats after parabiosis of old rats with young rats. Young rats, however, showed no changes in these levels after parabiosis. The serum cholesterol level and the biliary and fecal CA/CDCA ratios in old rats were higher than those in young rats but decreased after parabiosis with young rats, although they were still higher than those in young rats. The serum cholesterol level in young rats increased after parabiosis with old rats, but not after parabiosis with young rats, and the fecal bile acid level and the CA/CDCA ratio were not changed in either case. It is concluded from these findings that the serum cholesterol level and the CA/CDCA ratio increased with age and that these increases were prevented after parabiosis with young rats while young rats, although their serum cholesterol level was increased, showed no increase in the CA/CDCA ratio after parabiosis with old rats.

New trends for practice in telecommunication applied to preventive and environmental medicine

This paper presents survey results of connectivity to the Internet from preventive and environmental medicine-related departments in medical schools and other institutions in Japan and propose means to establish connectivity among them. Of 191 facilities surveyed, 134 (70%) responded by March 31, 1996. The data presented here are from 132 facilities. One hundred seventeen facilities (89%) answered that they were connected to the Internet. More than 80% of them got access to the Internet in the past two years. One hundred three facilities (78%) answered that e-mail was available. Despite the large percentage being connected, only 11 facilities (8%) had their own homepages. However, just 6 months later more than 25 facilities could be found by their own homepages. The Global Health Network (GHNet) has been developed in the USA based upon the concept that the best means to produce improved health is a better surveillance and information system applying the latest telecommunication technology to public health. The GHNet will offer an initial homepage for Preventive and Environmental Medicine related facilities in Japan to promote and establish sustainable connectivity among them.

Elevated amyloid beta protein(1-40) level induces CREB phosphorylation at serine-133 via p44/42 MAP kinase (Erk1/2)-dependent pathway in rat pheochromocytoma PC12 cells

The deposition of amyloid beta protein (A beta) in the cerebral cortex is the pathological characteristic of Alzheimer's disease (AD), and patients with AD suffer from progressive memory loss. Transgenic experiments have revealed that long-term memory is dependent on cyclic AMP-response element binding protein, CREB. CREB phosphorylation at serine-133 is essential for its transcriptional activity. Here we demonstrated that A beta(1-40), at a concentration more than 1 microM, induced CREB phosphorylation at serine-133 in rat pheochromocytoma PC12 cells. A beta(1-40) induced phosphorylation of p44 and p42 MAP kinases (Erk1 and Erk2) at tyrosine-204, and PD98059, a MEK1 inhibitor, inhibited A beta(1-40)-induced CREB phosphorylation at serine-133. We conclude that elevated A beta(1-40) level induces CREB phosphorylation at serine-133 via p44/42 MAP kinase-dependent pathway.

Generation of free radicals during lipid hydroperoxide-triggered apoptosis in PC12h cells

The compound 13-L-hydroperoxylinoleic acid (LOOH) triggered the death of clonal rat pheochromocytoma PC12h cells (LD50 = about 8 microM). LOOH induced nuclear condensation and DNA fragmentation, which was prevented by cycloheximide (a protein synthesis inhibitor) and NGF, indicating that LOOH triggered apoptosis in PC12h cells. LOOH produced reactive oxygen species (ROS) in PC12h cells in a time- and dose-dependent manner, as measured by flow cytometry using the ROS-specific fluorescent indicator, 6-carboxy-2,7-dichorodihydrofluorescein diacetate, di(acetoxymethyl ester) (C-DCDHF-DA). Antioxidants such as N,N'-diphenyl-p-phenylenediamine (DPPD), vitamin E and N-acetylcysteine, and a ferric iron chelator, deferoxamine, inhibited the LOOH-triggered apoptosis and simultaneously decreased the generation of ROS, whereas an inhibitor of glutathione synthesis, buthionine sulfoximine (BSO), enhanced the apoptosis and increased the generation of ROS. These results indicate that LOOH triggers the apoptosis of PC12h cells by increasing the production of ROS. A confocal analysis with the Ca(2+)-specific fluorescent indicator, fluo-3, demonstrated that LOOH at concentrations up to 200 microM, did not increase the intracellular Ca2+ concentration. These data indicate that LOOH induces apoptosis of PC12h cells through the enhanced production of ROS, not through increasing the permeability of Ca2+.

Determination of a new podophyllotoxin derivative, TOP-53, and its metabolite in rat plasma and urine by high-performance liquid chromatography with electrochemical detection

A high-performance liquid chromatographic method was developed for the determination of a new podophyllotoxin derivative, TOP-53 (I), and TOP-53 glucuronide (II) as its major metabolite in rat plasma and urine. For the analysis of I, the sample was chromatographed on a reversed-phase C18 column with electrochemical detection after consecutive two-step liquid-liquid extractions. Compound II was determined as I after enzymatic hydrolysis of II. This method was validated sufficiently with respect to specificity, accuracy, and precision. The limits of quantitation for both I and II were 2 ng/ml in plasma and 10 ng/ml in urine. The method is thus useful for the pharmacokinetic study of I.

Molecular cloning and expression of cDNAs encoding rat brain and liver cytosolic long-chain acyl-CoA hydrolases

cDNAs encoding the long-chain acyl-CoA hydrolases (ACHs) from rat brain and liver, referred to as rBACH and rLACH1, respectively, were isolated and sequenced. The rBACH cDNA contained an open reading frame encoding a 338-amino acid polypeptide with a calculated molecular weight of 37,559, of which the deduced amino acid sequence matched partial amino acid sequences directly determined for peptides generated by tryptic digestion or CNBr cleavage of purified rBACH. The rLACH1 cDNA contained an open reading frame encoding a 343-amino acid polypeptide with a molecular weight of 38,240. When expressed in Escherichia coli, these cDNAs produced palmitoyl-CoA hydrolase activity and 44-kDa proteins with molecular masses similar to those of purified rBACH and rLACH1 (43 kDa). These expressed proteins and enzyme activity were immunoblotted and neutralized, respectively, by anti-rBACH or anti-rLACH1 antibodies. rLACH1 cDNA had 84 and 94% identity with rBACH cDNA at the nucleotide and amino acid levels, respectively. However, the 5'-end of the former cDNA which contained the N-terminal coding region of rLACH1 was entirely different from the corresponding region of rBACH cDNA, suggesting that these enzymes may be generated by alternative use of exons of the same gene. Northern blot analysis showed that ACH mRNA was expressed constitutively in the rat brain and testis, whereas its expression in the liver was inducible by treatment with the peroxisome proliferator. This study demonstrated the molecular diversity of ACH and suggested the presence of tissue-specific mechanisms to regulate the ACH gene expression.

Ras-dependent activation of c-Jun N-terminal kinase/stress-activated protein kinase in response to interleukin-3 stimulation in hematopoietic BaF3 cells

Activation of the c-Jun N-terminal kinase (JNK)/stress-activated protein kinase pathway in response to stimulation of the interleukin (IL)-3 or granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor was examined in mouse hematopoietic BaF3-derived cell lines (BaF3-N6 and -V2 cells). Significant increase in the activity of JNK1 was observed within 30 min following IL-3 or GM-CSF stimulation at physiological concentrations. Dominant-negative Ras(S17N), which is conditionally expressed in the presence of isopropyl-1-thio-beta-D-galactoside in BaF3-N6 cells, prevented the IL-3 stimulation of JNK1, whereas anisomycin-induced JNK1 activation was unaffected. Furthermore, a deletion mutant of the common beta subunit for IL-3 and GM-CSF receptors that consists of only the membrane-proximal region, including box 1 and box 2 motifs, was incapable of facilitating JNK1 activity as well as Ras activation. These results provide evidence that Ras is required for IL-3-stimulated JNK1 activation. We also examined if constitutively active Ras(G12V) alone could stimulate JNK1 activity by using the inducible expression system. Isopropyl-1-thio-beta-D-galactoside induction of Ras(G12V) in the BaF3-V2 cell line caused no significant increase in JNK1 activity, which could be activated by IL-3 or anisomycin. On the contrary, the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway was fully activated following Ras(G12V) induction. Together with these results, it seems likely that the Ras protein is indispensable for the IL-3 stimulation of JNK1 although Ras activation by itself is insufficient for JNK1 activation.

A novel method to evaluate thromboresistance of drip chambers with filter used in extracorporeal blood circuits for hemodialysis

We have developed a novel method to simultaneously evaluate thromboresistance of two different types of drip chambers with a filter used in extracorporeal blood circuits for hemodialysis using canine arteriovenous shunt models. Bilateral bypasses between the femoral artery and vein on both sides of the animal were formed with 2 test circuits consisting of polyvinyl chloride tubing and two types of drip chambers with filters. Blood flow was derived into the drip chambers with a filter and returned to the femoral vein without using peristaltic pumps and systemic anticoagulants. By monitoring the quantitative changes of the blood flow rate through each drip chamber with a filter and measuring the time elapsed before the blood flow through its was completely obstructed by clots, thromboresistance of the drip chambers was evaluated under the same blood conditions. The drip chamber with a filter that had a small effective filter area, a big pore size, and slitlike pores showed better thromboresistance. This novel method proved useful in evaluating the thromboresistance of differently designed drip chambers with a filter.

Expression of thyrotropin-releasing hormone (TRH) receptor mRNA in somatotrophs in the rat anterior pituitary

A response of growth hormone (GH) to thyrotropin-releasing hormone (TRH) is observed in lower mammals and patients with diseases such as a cromegaly, but not in normal subjects. We have previously demonstrated the existence of intact TRH receptor mRNA in GH-secreting adenoma. To examine whether intact somatotrophs in the anterior pituitary also express TRH receptor, we attempted to localize both TRHR mRNA and GH immunoreactivity simultaneously. In situ hybridization analysis revealed TRHR mRNAs specifically in the anterior pituitary, and 61.1% of the anterior pituitary cells expressed this transcript. Staining for GH and PRL on the same samples showed that the somatotrophs apparently expressed TRHR mRNA and approximately 62.3% and 30.9% of hybridization-positive cells were somatotorophs and mammotrophs, respectively. Moreover, TRHR mRNA level in the somatotrophs expressed as the number of silver grains per cell was equivalent to that in the mammotrophs. These findings demonstrated expression of the TRHR mRNA in somatotrophs in the rat anterior pituitary, and also showed that more than 50% of the TRHR mRNA detected in the anterior pituitary was derived from these cells.

A computer screening approach to immunoglobulin superfamily structures and interactions: discovery of small non-peptidic CD4 inhibitors as novel immunotherapeutics

The interaction between CD4 and major histocompatibility complex (MHC) class II proteins is critical for the activation of CD4+ T cells, which are involved in transplantation reactions and a number of autoimmune diseases. In this study we have identified a CD4 surface pocket as a functional epitope implicated in CD4-MHC class II interaction and T-cell activation. A computer-based strategy has been used to screen approximately 150,000 non-peptidic organic compounds in a molecular data base and to identify a group of compounds as ligands of the proposed CD4 surface pocket. These small organic compounds have been shown to specifically block stable CD4-MHC class II binding, and exhibit significant inhibition of immune responses in animal models of autoimmune disease and allograft transplant rejection, suggesting their potential as novel immunosuppressants. This structure-based computer screening approach may have general implications for studying many immunoglobulin-like structures and interactions that share similar structural features. Furthermore, the results from this study have demonstrated that the rational design of small non-peptidic inhibitors of large protein-protein interfaces may indeed be an achievable goal.

alpha 2A subtype of presynaptic alpha 2-adrenoceptors modulates the release of [3H]-noradrenaline from rat spinal cord

The modulation of noradrenaline (NA) release from rat spinal cord slices was investigated and the subtype of presynaptic alpha 2-adrenoceptors involved in the negative feedback modulation was characterized using in vitro perfusion experiments. Rat spinal cord slices were loaded with [3H]NA and the release of radioactivity at rest and in response to field stimulation was determined. The alpha 2-adrenoceptor agonists, clonidine and dexmedetomidine inhibited the stimulation-evoked release of NA from spinal cord slices, whereas alpha 2-adrenoceptor antagonists yohimbine and CH-38083 (7,8-(methylenedioxy)-14-alpha-hydroxyalloberbane HCI), enhanced it. ARC 239, a selective alpha 2B-antagonist, had no effect on the release. In contrast, BRL 44408 a selective alpha 2A-antagonist increased the release of NA. Our results indicate that the negative feedback modulation of NA release from noradrenergic fibres in the spinal cord is mediated via alpha 2A subtype of alpha 2-adrenoceptors.

Polymorphonuclear cells in chronic hemodialysis patients have intact phagocytotic and impaired bactericidal activities

Although it has been well documented that chronic hemodialysis (HD) patients are highly susceptible to infectious diseases, the reasons for this have yet to be clarified. The present study was thus designed in order to better define this issue. Fifty-eight stable chronic HD patients without any evidence of infection were selected for the study. Blood samples were collected before and after HD from the same patient to determine the effect of HD. Reactive oxygen species (ROS) production in polymorphonuclear cells (PMNC) was measured by chemiluminescence using luminol. When the PMNC collected after HD were stimulated in vitro with a calcium ionophore (A23187), they produced a larger amount of ROS than that obtained from healthy volunteers [mean 7.4 x 10(5) photon counts (n = 58) vs. 3.0 x 10(5) photon counts (n = 17); p < 0.01]. A higher production of ROS after HD was seen in patients using membranes such as cellulose triacetate, polymethylmetacrylate and cellulose diacetate, whereas cuprophane did not seem to augment ROS production at all. On the other hand, when the PMNC after HD were stimulated with phorbol myristate acetate, their photon counts (mean 4.3 x 10(7)) were comparable to those before HD (mean 3.5 x 10(7)), and to those of PBMC obtained from healthy volunteers (mean 4.1 x 10(7)). It was thus suggested that the enhanced ROS production of PMNC was related to some stimuli, possibly even to the assay used to measure ROS. The phagocytotic activity and bactericidal effect of PBMC were measured by coculturing 1 x 10(5) PMNC with 1 x 10(5) CFU of Escherichia coli. Similar phagocytotic activities were noted in the PMNC from healthy volunteers and chronic HD patients before and after HD: the mean number of phagocytosed bacteria (log10 CFU) was 3.3, 3.3, and 3.3, respectively. However, in the case of a bactericidal effect, only the PMNC from healthy volunteers, but not the PMNC from HD patients, could effectively kill the bacteria, since the number of bacteria in PMNC decreased from 10(3.3) to 10(2.1). The PMNC from HD patients could not kill the bacteria-regardless of the characteristics of the membranes. It was thus concluded that the PMNC of chronic HD patients possess an intact phagocytotic activity which impaired bacterial killing, and was probably due to an abnormality occurring in the ROS production pathway.