Age-related changes of mRNA expression of amyloid precursor protein in the brain of senescence-accelerated mouse

APP695 mRNA is only expressed in the brains of SAM. The expression of APP mRNA in SAM P1 mice brains is more marked than that in SAM R1 mice brain. APP mRNA expression was increased with advancing age in all brain regions of SAM P1 mice compared with SAM R1. Especially, the changes of the amount of APP mRNA in the prosencephalon and the mesencephalon are significant at P value of 0.05. We suggest that overexpression of APP mRNA may be related to accelerated aging phenomenon in the SAM brain. This is the first report of age-related increase in the amount of APP mRNA in the SAM brain.

Effectiveness of endoscopic ultrasonography in the diagnosis of choledocholithiasis prior to laparoscopic cholecystectomy

BACKGROUND AND STUDY AIMS

To reduce the rate of conversion to open cholecystectomy, and to avoid retained bile duct stones, it is essential to detect choledocholithiasis prior to laparoscopic cholecystectomy. The aim of the present study was to evaluate the usefulness and safety of performing endoscopic ultrasonography (EUS) for the diagnosis of choledocholithiasis prior to laparoscopic cholecystectomy.

PATIENTS AND METHODS

One hundred thirty-two patients with symptomatic cholelithiasis were evaluated prospectively using standard abdominal ultrasonography (US), US plus EUS, and US plus endoscopic retrograde cholangiography (ERC) for the detection of choledocholithiasis prior to laparoscopic cholecystectomy.

RESULTS

Twenty-eight patients (21.2%) had choledocholithiasis, and six patients with common bile duct stones had normal-sized ducts on US. The common bile duct was successfully examined in all patients using EUS, but only in 65.9% of patients when US was used and 94.7% of patients when ERC was used. US plus EUS detected choledocholithiasis in 25 of 28 patients (89.3%), US in 19 of 28 patients (67.9%), and US plus ERC in 26 of 28 patients (92.9%). While no complications as a result of EUS were encountered, complications resulting from ERC occurred in seven patients (5.3%), including cholecystitis in two patients, cholangitis in three patients, and pancreatitis in two patients. In view of the complication and failure rates, EUS appears to offer significant advantages over ERC. These results suggest that EUS is more sensitive than standard abdominal ultrasonography, and as sensitive as ERC.

CONCLUSIONS

EUS appears to be as sensitive as, and safer than, ERC in the detection of choledocholithiasis prior to laparoscopic cholecystectomy.

Immune suppression therapy in aplastic anemia: influencing factors on response and survival

OBJECTIVES

Immune suppression (IS) therapy has provided another opportunity of cure or improvement in the aplastic anemia patients who cannot receive bone marrow transplantation due to many causes. There are a few reports regarding the factors that affect response, survival and prognosis after IS therapy, including antilymphocyte globulin (ALG) in aplastic anemia. Therefore, we analysed our experience to determine the prognostic factors.

METHODS

Statistically analysed were 172 patients, from April 1982 to July 1992, who were diagnosed as severe aplastic anemia and treated with IS therapy, including ALG, at Catholic University Medical College, St. Mary's Hospital.

RESULTS

Among 172 severe aplastic anemia (SAA) patients who entered the study from April 1982 to July 1992, 144 patients were analysed for response and 122 patient for survival. 58.4% (84/144) responded after the first course of IS therapy. Among those who did not respond on the first course an additional 44% (11/25) responded after the second course of IS therapy. Prognostic factors that might affect the response to the treatment and survival were analysed. In a univariate analysis of patients with no previous history of treatment before is therapy, and a shorter interval between diagnosis and treatment, higher hemoglobin levels before IS therapy, and higher granulocyte counts and combined use use of cyclosporin A(CSA) were positively associated with response (p < 0.05). The combined use of CSA during IS therapy, younger age, lower monthly requirement of platelets transfusion before IS therapy, higher leukocyte counts, higher percent of polymorphonuclear leukocytes, lower percent of lymphocyte, higher bone marrow cellularity and response were positively associated with survival (p < 0.05). In a multivariate analysis, shorter interval between diagnosis and treatment, no combined use of hemopoietic stimulants, such as androgen, and lesser total amount of transfusion were positively associated with Response (p < 0.05). Higher leukocyte counts before IS therapy and the combined use of CSA during IS therapy were significantly associated with longer survival (p < 0.05). Patients with complete or partial response had excellent prognosis (96.7%-100% of 5 year survival rates). In contrast, patients with no response after IS therapy had 45.1% of 5 year survival rates.

CONCLUSIONS

With these results from the retrospective study of IS therapy, we find many valuable factors that have an influence on response or survival. IS therapy improves the survival of responded patients with SAA, and we confirmed that IS therapy is an important therapeutic tool for the SAA patients who are not feasible candidates for bone marrow transplantation.

Complete nucleotide sequence and tissue-specific expression of the rat phenylethanolamine N-methyltransferase gene

The rat phenylethanolamine N-methyltransferase (PNMT) gene was isolated from a genomic library by cross-hybridization with a bovine PNMT cDNA probe. Complete nucleotide sequence analysis of a genomic clone showed that this gene contained three exons and spanned about 2.8 kb in length. There were the acute-phase response element, TATA, SP1, and GRE sequences. The physicochemical properties of rat adrenal PNMT were different from those of the brainstem PNMT. However, northern blot and reverse transcription-polymerase chain reaction analysis showed that the rat PNMT gene may not express the multiple forms of mRNA. These results suggest that the rat PNMT gene might produce a single enzyme protein, whose activity may be differentially modulated by tissue-specific environment in the central and peripheral systems.

General pharmacology of cis-malonato[4R,5R)-4,5-bis-(aminomethyl)-2-isopropyl-1,3- dioxolane]platinum(II)

The general pharmacological properties of cis-malonato-[(4R,5R)-4,5- bis(aminomethyl)-2-isopropyl-1.3-dioxolane]platinum(II) (SKI 2053R, CAS 146665-77-2), a new potential anticancer agent, were investigated in mice, rats, guinea pigs, rabbits, cats and dogs. Intravenous administration of SKI 2053R had no effect on the central nervous system. SKI 2053R had no effect on the autonomic nervous system and smooth muscles except that it slightly inhibited the spontaneous motility of isolated rabbit ileum at a concentration of 5 x 10(-5) g/ml. SKI 2053R did not adversely affect the respiratory-cardiovascular system, gastrointestinal system, neuromuscular junction, or renal function. SKI 2053R did not significantly alter the levels of serum glucose, serum free fatty acid and plasma lactate, and did not induce hemolysis. SKI 2053R did not affect blood coagulation mechanism and liver function. SKI 2053R did not exhibit anti-inflammatory activity. It was observed that SKI 2053R increased the formation of hemolytic plaque by spleen cells of sensitized mice at high doses (10 mg/kg and 35 mg/kg). Therefore, it is concluded from these general pharmacological studies that SKI 2053R at the doses showing antitumor activity does not induce severe adverse effects on the central nervous, autonomic nervous, respiratory-cardiovascular, gastrointestinal, peripheral nervous, and other systems in experimental animals.

Allogeneic bone marrow transplantation in Korea: 1983-92

Between March 1983 and December 1992, we performed 178 allogeneic BMTs for patients with hematopoietic stem cell disorders: 48 acute myelogenous leukemia (AML), 27 acute lymphoblastic leukemia (ALL), 40 chronic myelogenous leukemia (CML), 55 severe aplastic anemia (SAA), 6 myelodysplastic syndrome (MDS), 1 non-Hodgkin's lymphoma and 1 hybrid leukemia. Twenty-five of 48 AML are in disease-free survival (DFS). Fifteen of 27 ALL are in unmaintained remission. Twenty-four of 40 CML are in DFS. Forty-four out of 55 SAA patients are alive and well. Comparing the survival between standard (< or = CR1: 21 of 31 (68%)) and high risk (> or = CR2: 4 of 17 (24%)) AML, our data suggest that the preparative regimen for high risk AML was not potent enough to eradicate the residual disease in advanced AML. Although our cases are limited and the follow-up period is short, the result of ALL (overall: 56%, standard risk (adult < or = CR1, children < or = CR2: 10 of 14 (71%) and high risk (adult > or = CR2, children > CR2): 5 of 13 (38%)) and CML (overall: 60%; CP: 19 of 27 (70%), AP or BC: 5 of 13 (38%)) are promising. The probability of 5 year survival of SAA was 80 +/- 4 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial expression, purification of full length and carboxyl terminal fragment of Alzheimer amyloid precursor protein and their proteolytic processing by thrombin

Human amyloid protein precursor(APP770) and its carboxyl terminal portion (CT105) including beta/A4 domain were highly expressed using strong expression systems in E. coli. These recombinant APP peptides were purified with a combination of urea solubilization and ion-exchange chromatography and used for proteolytic processing by thrombin. Three thrombin cleavage sites were predicted by the decrease of APP770 and the appearance of M(r) 56, 27 and 18 kDa fragments containing beta/A4 domain on SDS-PAGE gel and on the immunoblot. A similar but limited proteolysis of platelet APPs exposed to thrombin resulted in the stimulated production of 60 and 27 KDa carboxyl terminal peptides containing the intact beta/A4. This thrombin mediated proteolysis was completely blocked by hirudin, the specific thrombin inhibitor. These results suggest that thrombin may play a role in altered processing of APP to generate potentially amyloidogenic intermediates in vivo leading to amyloid deposition.

Ligand binding characteristics of [3H] dihydroalprenolol in cerebral cortical membranes of young and old senescence-accelerated mouse

1. The values of both Kd and Bmax of [3H] dihydroalprenolol binding in the cerebral cortical membranes of old-aged (12 month old) SAM-P/1 were not significantly different compared with those of young (2 month old) SAM-P/1. 2. The values of Ki of metoprolol in the young and old aged SAM were 119 +/- 39.5 nM and 157 +/- 55 nM, respectively. 3. The values of beta 1/beta 2 ratio of the young and old aged SAM were 1.67 +/- 0.15 and 1.64 +/- 0.13, respectively. 4. These results suggest that there were no significant changes of binding characteristics of beta 1 and beta 2 adrenoceptors during aging in the cerebral cortex of SAM.

Subunit structure of cell-specific E box-binding proteins analyzed by quantitation of electrophoretic mobility shift

Expression of insulin and immunoglobulin genes is dependent on the presence of E boxes (consensus sequence CAXXTG) within the enhancer regions. These sequences are recognized by cell-specific nuclear factors IEF1 (insulin enhancer factor 1) and LEF1 (lymphoid enhancer factor 1). Although IEF1 and LEF1 are distinct by several parameters, they are both recognized by antisera to the mouse helix-loop-helix (HLH) protein A1 (a homolog of the human protein E47, product of the E2A gene). This suggests that A1/E47 or a close relative is a component of both complexes. In order to further characterize the complexes, we have used in vitro translated DNA-binding proteins of known size to verify that electrophoretic mobility shift analysis can be used to estimate the molecular weight of DNA-binding proteins from both the HLH family and the leucine zipper family. Under the conditions used, migration is relatively insensitive to changes in protein charge. This analysis, in combination with mixing experiments between nuclear extracts and in vitro translated HLH proteins, indicates that IEF1 and LEF1 are dimeric complexes. IEF1 behaves as a complex of two proteins, one of which is 67 kDa and is recognized by antibodies to A1, and the second of which is 25 kDa. LEF1 on the other hand, appears to be a complex of two proteins of 67 kDa. The size of the 67-kDa subunits is consistent with that reported for the full-length E2A gene products. The 25-kDa subunit of IEF1 forms DNA-binding heterodimers with A1 but not MyoD and is present in a limited range of cell types, features characteristic of class B HLH proteins such as MyoD and achaete-scute. Taken together, the data support the idea that the E2A gene products are involved directly in regulation of insulin and immunoglobulin gene expression; regulation of the insulin gene apparently requires, in addition, the 25-kDa HLH protein (designated IESF1 for insulin enhancer-specific factor 1).

Allogeneic bone marrow transplantation for the patients with hemopoietic stem cell disorders: CUMC experience

Bone marrow transplantation from an HLA-identical sibling is increasingly used as a curative therapy for patients with hemopoietic stem cell disorders including acute leukemia, chronic myelogenous leukemia and severe aplastic anemia. Between March 1983 and March 1991, we performed 86 cases of allogeneic bone marrow transplantation (BMT) for the patients with hemopoietic stem cell disorders: 25 acute myelogenous leukemia (AML); 15 acute lymphoblastic leukemia (ALL); 20 chronic myelogenous leukemia (CML); and 26 severe aplastic anemia (SAA). Ten out of 25 AML are in disease free survival (DFS). The causes of death were recurrence of leukemia (12), acute GVHD (3), sepsis (1) and veno-occlusive disease (1). Nine of 15 ALL are in unmaintained remission. Thirteen out of 20 CML are in DFS. Among 26 SAA, 21 are enjoying DFS, but 1 died of engraftment failure, 3 of graft rejection followed by cytomegalovirus (1) and aspergillus pneumonia (1). Comparing the survival between standard [less than or equal to CR1: 9/14 (64%)] and high risk [greater than or equal to CR1: 1/11 (9%)] AML, our data suggest that preparative regimen for high risk AML was not potent enough to eradicate the minimal residual disease in advanced AML. Although our cases are limited and the follow-up period is short, our result of ALL [overall: CCR (60%), standard risk (adult less than or equal to CR1, children less than or equal to CR2; 8/11 (73%) and high risk; 1/4 (25%)] and CML [overall: 65%, CP; 9/10 (90%), AP; 4/6 (67%), BP; 0/4 (0%)] are optimistic. It is of our interest that the incidence of death related with IP (1/33: 3%) and with AGVHD 94/33: 12%) were much less than that of other's observation but the explanation for this still remains to be clear.

Pharmacological evaluation of GS-389, a novel tetrahydroisoquinoline analog related to higenamine, on vascular smooth muscle

The effects of GS-389, a novel tetrahydroisoquinoline analog, on isolated rat and mouse thoracic aorta rings, were investigated. Both GS-389 and papaverine induced endothelium-independent, concentration-dependent relaxations of the rat and mouse aortae precontracted with phenylephrine (PE). The GS-389-induced inhibition of the contractile response to PE was noncompetitive. The initial phasic contraction to PE elicited in Ca(2+)-free media was also attenuated by pretreatment with GS-389, indicating that GS-389 may interfere with the release of intracellular Ca2+ and/or the effects of intracellular Ca2+ release. GS-389 potentiated the vasodilatory effects of isoproterenol and sodium nitroprusside in rat and mouse aortae. GS-389 significantly increased cGMP levels in the rat aorta and inhibited cGMP phosphodiesterase from the rabbit brain. Methylene blue, but not propranolol, inhibited the vasodilatory effect of GS-389. These results suggest that the vasorelaxant effect of GS-389 may be due, at least in part, to inhibition of cGMP metabolism.

Metoprolol oxidation polymorphism in a Korean population: comparison with native Japanese and Chinese populations

We examined metoprolol oxidation capacity in 218 unrelated, healthy Korean subjects using the 8 h urinary metabolic ratio (MR) of metoprolol to alpha-hydroxymetoprolol after an oral dose of 100 mg metoprolol tartrate. The results were compared with those from 295 Japanese and 107 mainland Chinese whose metoprolol oxidation capacities were assessed in a similar manner. The frequency of occurrence of poor metabolisers (PMs) was 0.5% (1/218) in the Korean, 0.7% (2/295) in the Japanese and 0% in the Chinese population. However, the respective mean (+/- s.d.) MRs (0.84 +/- 1.14 and 0.87 +/- 0.90) in the Korean and Japanese extensive metabolisers (EMs) were significantly (P less than 0.001) less than that in the Chinese EMs (2.81 +/- 2.35), and the mode of the distribution histogram and the probit plot of data for Chinese EMs were shifted to the right compared with those for Korean and Japanese EMs. The results indicate that Koreans, like Japanese and mainland Chinese, have a much lower frequency of the PM phenotype of debrisoquine/sparteine-type oxidation compared with that reported for Caucasian populations. Chinese EMs appear to have a lower capacity to metabolise metoprolol to alpha-hydroxymetoprolol compared with Korean or Japanese EMs.

Distribution and characterization of helix-loop-helix enhancer-binding proteins from pancreatic beta cells and lymphocytes

Transcription of a number of mammalian genes is controlled in part by closely-related DNA elements sharing a CAxxTG consensus sequence (E boxes). In this report, we survey cell extracts from a variety of mammalian cell lineages for ability to bind to the E box denoted IEB1/kappa E1, which plays an important role in expression of both insulin and immunoglobulin kappa genes. Insulin enhancer factor 1 (IEF1), a binding activity previously identified in beta cells, was also present in pituitary endocrine cells but absent in 7 other mammalian cell lines tested. A distinct binding activity, lymphoid enhancer factor 1 (LEF1), was observed in several lymphoid cell lines, but was absent from all nonlymphoid cells tested. IEF1 and LEF1 were distinct according to electrophoretic mobility, and DNA binding specificity. As previously reported, both beta cell and lymphoid cell factors are recognized by antibodies to helix-loop-helix (HLH) proteins, indicating that they may contain functional helix-loop-helix dimerization domains. To directly demonstrate this, we showed that the binding factors are able to interact in vitro with the HLH domain of a characterized HLH protein. These results support the notion that HLH proteins play a key role in cell-specific transcriptional regulation in cells from endocrine and lymphocyte lineages.

A cDNA from a mouse pancreatic beta cell encoding a putative transcription factor of the insulin gene

Cell specific expression of the insulin gene is achieved through transcriptional mechanisms operating on multiple DNA sequence elements located in the 5' flanking region of the gene. Of particular importance in the rat insulin I gene are two closely similar 9 bp sequences (IEB1 and IEB2): mutation of either of these leads to 5-10 fold reduction in transcriptional activity. We have screened an expression cDNA library derived from mouse pancreatic endocrine beta cells with a radioactive DNA probe containing multiple copies of the IEB1 sequence. A cDNA clone (A1) isolated by this procedure encodes a protein which shows efficient binding to the IEB1 probe, but much weaker binding to either an unrelated DNA probe or to a probe bearing a single base pair insertion within the recognition sequence. DNA sequence analysis indicates a protein belonging to the helix-loop-helix family of DNA-binding proteins. The ability of the protein encoded by clone A1 to recognize a number of wild type and mutant DNA sequences correlates closely with the ability of each sequence element to support transcription in vivo in the context of the insulin 5' flanking DNA. We conclude that the isolated cDNA may encode a transcription factor that participates in control of insulin gene expression.

Kinetics of isoniazid transfer into cerebrospinal fluid in patients with tuberculous meningitis

For the pharmacokinetic analysis of isoniazid transfer into CSF, steady-state isoniazid concentrations of plasma and CSF were measured in eleven tuberculous meningitis patients confirmed with findings of CSF and neuroimazing. Peak plasma levels (4.17-21.5 micrograms/mL) were achieved at 0.25 to 3 hours after multiple isoniazid dose (600 mg/day). Terminal half-life, total clearance (CI/F) and volume of distribution (Vd/F) were 1.42 +/- 0.41 hr, 0.47 +/- 0.22 L/kg/hr and 0.93 +/- 0.48 L/kg, respectively. Isoniazid concentrations in CSF collected intermittently were highest at 3 hr (Mean, 4.18 micrograms/mL) and were 0.54 +/- 0.21 micrograms/mL at 12 hrs after the last dose of isoniazid 10 mg/kg/day. CSF/plasma partitioning of isoniazid and equilibration rate were estimated using modified pharmacokinetic/pharmacodynamic model. Disposition rate constant from CSF to plasma and CSF/plasma partitioning ratio of isoniazid were estimated to be 0.39 h-1 and 1.17, respectively.

Cloning and analysis of the pseudogene for human epinephrine synthesizing enzyme, phenylethanolamine N-methyltransferase (PNMT)

1. This gene completely lacks the intervening sequences. 2. This gene is truncated at the 5' end peptide encoding region by 433 base pairs (bp). 3. The 502 bp of this gene containing poly(A) signal are completely identical to the 3' half of mRNA encoding region of functional gene. 4. This gene has a poly(A) tail and is flanked by direct repeat of 6 bp. 5. Here we report for the first time the complete sequence of a human pseudogene for phenylethanolamine N-methyltransferase and this is the first report of cloning of pseudogene for catecholamine biosynthetic enzymes.

In vitro effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on muscarinic cholinergic receptors in mouse striatum

1. MPTP significantly lowered Kd of the binding of [3H]QNB to muscarine receptor without affecting Bmax values compared with those of control. Hill coefficients (nH) of control and MPTP (250 microM) added group were 1.15 +/- 0.127 and 0.56 +/- 0.202, respectively. 2. Prior addition of pargyline to MPTP did not prevent the decrease of [3H]QNB binding. The patterns of displacement of [3H]QNB by MPTP and MPP+ were similar to those by some muscarinic agonists, such as acetylcholine, carbamyl choline and methacholine. 3. These results suggest that MPTP might be muscarinic agonist and might play a role to produce Parkinsonism through directly affecting the muscarinic cholinergic receptors in vivo.

Immunomodulation therapy for severe aplastic anemia--ALG versus ALG plus cyclosporin A

Immunosuppressive treatment of aplastic anemia has been increasingly used as an alternative treatment to bone marrow transplantation. In this study, the additive effect of Cyclosporin A (CSA) (5mg/kg/day, at least 3 months) for maintenance of immunosuppression after antilymphocyte globulin (ALG) therapy (40mg/kg/day for 4 days) was compared to the previous ALG alone treatment (15mg/kg/day for 10 days). A high dose of methylprednisolone (20mg/kg/day for 5 days and 10mg/kg/day for 5 days) to the ALG group and a low dose of methylprednisolone (2mg/kg/day for 5 days) to the ALG plus CSA group were administered simultaneously. The results were as follows: 1) Sixteen (69.6%) out of twenty-three patients treated with ALG plus Cyclosporin A showed higher responses (CR: 48%, PR: 22%). On the contrary, nine out of nineteen in the ALG group showed lower responses (CR: 21%, PR: 26%). 2) Our data showed a tendency that male patients in age ranging from sixteen to thirty years showed an excellent response to ALG therapy (12/23: 52.2%). 3) The ALG plus CSA group revealed a faster response compared to the ALG alone group (15/16 within 6 months). 4) We speculate that ALG plus CSA therapy might be the treatment of choice for patients with a moderate degree of aplastic anemia. 5) Adding CSA to ALG increased the chance of infection, such as those with URI-like symptoms, but it did not affect the mortality rate. Our data suggest that the ALG plus CSA regimen may be a more useful therapeutic modality for patients with severe aplastic anemia who cannot be candidates for bone marrow transplantation and a randomized multicenter study is needed for confirmation of our preliminary study.

Effects of higenamine on isolated heart adrenoceptor of rabbit

In the present study, effects of higenamine on various mechanical parameters of rabbit left atria as influenced by propranolol were investigated and compared to those of epinephrine. The following results are obtained: Higenamine, in a dose-dependent manner, increased the rate of tension development and shortened both the time to peak tension and the total duration of contraction. These effects of higenamine were competitively blocked by propranolol. The pA2 values of higenamine and epinephrine against propranolol were 8.58 +/- 0.14, 7.50 +/- 0.82 respectively, and the slopes by Schild plots were 0.97 and 0.99 with higenamine and epinephrine, respectively. The results indicate that the positive inotropic action of higenamine is likely due to stimulation of cardiac adrenoceptors.