Use of cilostazol, a novel antiplatelet agent, in a post-Palmaz-Schatz stenting regimen

We evaluated the therapeutic efficacy of cilostazol, a novel potent inhibitor of phosphodiesterase, for the prevention of stent thrombosis following implantation of a Palmaz-Schatz stent guided by angiographic visual estimation alone in 71 patients with 84 lesions. Patients received 81 mg of aspirin 3 times daily and 100 mg of cilostozol twice daily after angiographic confirmation of optimal Palmaz-Schatz stent implantation. Of the 84 vessels stented, 65 (77%) were classified as type B2 or C lesions according to the modified American Heart Association/American College of Cardiology classification, and 51 (61%) were <3.0 mm in diameter. Multiple stents were used in 26 patients (31%). The final balloon inflation pressure was 18.3 +/- 1.5 atm. The balloon-to-vessel ratio was 1.18 +/- 0.16. No patient received heparin or warfarin after the procedure. There were no deaths, Q-wave myocardial infarctions, in- or out-of-hospital stent thrombosis, coronary bypass surgery, or serious side effects such as neutropenia and/or liver dysfunction during the 1-month follow-up period. These results indicate that cilostazol was a safe and effective antiplatelet agent with minimum side effects after Palmaz-Schatz stent implantation.

Site-directed mutagenesis of active site contact residues in a hydrolytic abzyme: evidence for an essential histidine involved in transition state stabilization

Specific molecular interactions involved in catalysis by antibody 6D9 were investigated by site-directed mutagenesis. The catalytic antibody 6D9, which was generated against a transition state analog (III), hydrolyzes a non-bioactive chloramphenicol monoester derivative (I) to produce chloramphenicol (II). Construction of a three-dimensional molecular model of 6D9 and sequence comparison within a panel of related antibodies suggested candidates for catalytic residues, His (L27d), Tyr (L32), Tyr (H58) and Arg (H100b); these were targeted for the site-directed mutagenesis study. The Y-H58-F and R-H100b-A mutants possessed catalytic activities comparable to that of the wild-type, and the Y-H58-H and Y-L32-F mutant displayed an approximately fivefold decrease in k(cat)/Km. In the transition state analysis, the plots of logK(TSA) versus log(k(cat)/Km) for the mutants are linear, with a slope of approximately 1.0, indicating that the entire hapten-binding energy in the mutants is also utilized to bind the transition state and to accelerate the catalysis. In addition, a dramatic change in the catalytic activity was observed when the histidine residue (27d) in the CDR1 light chain was replaced with alanine. The H-L27d-A mutant had no detectable catalytic activity. This mutation led to a large, 40-fold reduction in transition state binding, with no change in substrate binding. Coupled with the previous kinetic studies and chemical modifications of the intact 6D9 antibody, this mutagenesis study has demonstrated that His L27d plays an essential role in stabilization of the transition state, the mechanism of catalysis by the 6D9 antibody.

Use of synchrotron radiation microangiography to assess development of small collateral arteries in a rat model of hindlimb ischemia

BACKGROUND

Current methods of angiography cannot provide images of arteries measuring < 200 microns in diameter. We have recently developed a new angiography system that uses monochromatic synchrotron radiation and a high-definition video system with a spatial resolution of 30 microns. In the present study, we applied this microangiography system to visualize small arteries in normal and ischemic rat limbs and investigated the development of collateral arteries.

METHODS AND RESULTS

Microangiography was performed in the normal and the ischemic limb 4 weeks after the excision of the femoral artery. In the normal limb, up to the fourth branches of the iliac and/or femoral arteries (diameter < 100 microns) were readily identified. Some of these branches were found to perfuse the distal thigh area. In the ischemic limb, an extensive structural remodeling of the vascular network was observed. Numerous small arteries had developed from the branches of the iliac artery to constitute a fine arterial network, the so-called "midzone," which was composed of linear, normal appearing arteries and those with an undulating, unbranched appearance.

CONCLUSIONS

The small collateral artery network was angiographically visualized with a resolution limit < 100 microns. The linear collaterals appeared to result from an opening of preexisting vessels. The undulating, unbranched vessels were not observed in the normal limbs and seemed to be vessels that were newly formed after limb ischemia. Synchrotron radiation microangiography appears to be a powerful means of assessing the development of small collateral arteries, which may help to provide a basis for understanding of the collateral circulation.

Structure, chromosomal localization and expression of mouse genes encoding type III Reg, RegIII alpha, RegIII beta, RegIII gamma

Reg (regenerating gene), first isolated from a rat regenerating islet cDNA library, is expressed in regenerating islet beta-cells. Recently, it has been revealed that Reg and Reg-related genes constitute a multigene family, Reg family, which consists of three subtypes (type I, II, III) based on the primary structures of the encoded proteins of the genes. In mouse, type I and type II Reg genes (i.e. RegI and RegII gene) have so far been isolated. In the present study, the complete nucleotide (nt) sequences of the cDNAs and genes encoding murine type III Reg (regenerating gene product), RegIII alpha, RegIII beta and RegIII gamma were determined. RegIII alpha, RegIII beta and RegIII gamma encode 175-, 175- and 174-amino acid (aa) proteins, respectively, with 60-70% homology. All three genes are composed of six exons and five introns spanning approx. 3 kb, and exhibit distinctive structural features unique for members of the Reg gene family. All the mouse Reg genes, RegIII alpha, RegIII beta, RegIII gamma, RegI and RegII, are assigned to the adjacent site of chromosome 6C by fluorescence in situ hybridization (FISH). RegIII alpha, RegIII beta and RegIII gamma were expressed weakly in pancreas, strongly in intestinal tract, but not in hyperplastic islets, whereas both RegI and RegII were expressed in hyperplastic islets. These results suggest that genes of the mouse Reg family are derived from a common ancestor gene by several gene duplications, and have obtained divergency in expression and function in the process of genetic evolution.

ST reelevation at reperfusion is associated with the occurrence of late potentials in patients with acute anterior infarction

The relationship between ST reelevation at reperfusion and the occurrence of late potentials (LPS) in 35 patients with a first anterior infarction who had single vessel disease was investigated. All patients underwent a successful primary angioplasty and had a patent infarct related artery confirmed angiographically 4 weeks later. Patients were classified into groups based on changes in the ST level at reperfusion: patients with ST reelevation (group A, n = 22) and patients without ST reelevation (group B, n = 13). Signal-averaged ECG was performed 4 weeks after primary angioplasty to detect LPS. Cineventriculography was performed to measure left ventricular ejection fraction (LVEF) and evaluate regional wall motion of the infarct area (SD/chords). LPS were present in eight of the 22 group A patients (36%) and in none of the 13 group B patients (P < 0.05). Left ventricular function was impaired in patients in group A compared with patients in group B (LVEF: 5 1 +/- 12 vs 63 +/- 10, P < 0.01; SD/chords: -2.7 +/- 0.9 vs -1.9 +/- 1.1, P < 0.05). These data suggest that ST reelevation and myocardial damage at reperfusion are associated with the occurrence of LPS in patients with successfully recanalized infarct related arteries after acute anterior infarction.

Angiographic and coronary risk factor analyses of Japanese patients with ischemic heart disease before age 40--a multicenter cooperative study

Coronary angiographic and risk factor (RF) characteristics were analyzed in 133 Japanese patients with ischemic heart disease (IHD) who were less than 40 years old and who had undergone coronary angiography (CAG) during the past 10 years at six university hospitals in the Tokyo area. We compared the coronary angiographic characteristics of the subject group with those of 216 controls with coronary sclerosis detected by CAG who were more than 40 years old (older control group) and the RF characteristics with those of 133 sex- and age-matched volunteers (younger control group). Sixty seven percent of the subjects (89 cases) were diagnosed as having myocardial infarction (MI) and 33% (44 cases) had angina pectoris (AP). Coronary artery disorders in this group consisted of 103 (77%) cases of coronary sclerosis, 20 (15%) cases of coronary spasm and 10 (8%) cases of miscellaneous diseases, eg, possible vasculitis with connective tissue disease, congenital anomalies, etc. The incidences of significant (> or = 75%) sclerotic narrowing in 0 vessels (31%) and 1 vessel (49%) in the subject group were significantly (p < 0.01) higher than those in the older control group, while the incidence of multivessel disease was significantly (p < 0.05) less in the subject group than in the older control group. The incidences of the following coronary risk factors were significantly (p < 0.05) higher in the subjects than in the younger controls: smoking (83% vs 35%), hypercholesteremia (44% vs 10%), obesity (31% vs 9%), hypertension (29% vs 3%), familial IHD (28% vs 7%) and diabetes mellitus (19% vs 2%). Thus, zero- or single-vessel disease predominated in the younger subject group and the prevalence of coronary risk factors was significantly higher in the subject.

Common reabsorption system of 1,5-anhydro-D-glucitol, fructose, and mannose in rat renal tubule

1,5-Anhydro-D-glucitol (AG) is a major polyol, 99.9% of which is reabsorbed by the kidney. However, such reabsorption is inhibited by competition with glucose excreted in excess, i.e., glucosuria. Under such conditions, AG is excreted into the urine. We administered various types of sugars to rats by continuous intravenous infusion for two hours to evaluate the competition between AG and these sugars for renal reabsorption in vivo. The reabsorption of AG was significantly inhibited by competition with fructose and mannose. The excretion of AG in the 120 min after a load of 3.64 mmol of fructose was 1.99 +/- 0.33 mumol, that after 3.64 mmol of mannose loading was 2.34 +/- 0.43 mumol. These levels were comparable to the AG excretion observed after the administration of the same amount of glucose (3.87 +/- 0.61 mumol). No competition was observed with sucrose, xylose, myoinositol or galactose. The reabsorption of fructose and mannose was significantly inhibited by the presence of AG (P < 0.001) after a mixed load. Results suggest that AG is reabsorbed in the renal tubule by an AG/fructose/mannose-common transport system that is distinct from the major glucose reabsorption system. These findings may help to clarify the specific transport systems for various sugars in the renal tubule, as well as their physiological importance.

Clinical usefulness of serum 1,5-anhydroglucitol in monitoring glycaemic control

BACKGROUND

To evaluate prospectively the clinical value of measuring serum concentrations of 1,5-anhydroglucitol (1,5AG) in monitoring glycaemia in patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM), we measured serum 1,5AG in 56 such patients.

METHODS

28 patients (group A) were started on, and continuously received, an oral hypoglycaemic agent for at least 6 weeks. The other 28 patients (group B) were given such agents for 4 weeks, and then stopped taking them for at least 2 weeks. All patients were then followed for an additional 10 weeks. Serum 1,5AG, fructosamine, glycated haemoglobin (HbA1c), and self-monitoring of blood glucose were monitored every 14 days for 16 weeks.

FINDINGS

When sudden worsening of glycaemia occurred within 2 weeks, entailing withdrawal of oral treatment, 1,5AG accurately detected the slight change in glycaemia whereas HbA1c and fructosamine both failed to detect it. Although the change was detected by measurement of fasting plasma glucose (FPG) concentrations, FPG was less sensitive than 1,5AG. In patients with "near-normoglycaemia" (HbA1c about 6.5%) in the preceding 8 weeks, those who showed a lower concentration of 1,5AG (<10.0 micrograms/mL) manifested a higher mean daily plasma glucose concentration even though HbA1c measurement suggested good control of glycaemia. Results of 1,5AG were correlated more strongly with the FPG (r=0.790) and mean daily plasma glucose (r=-0.835) estimated on the same day than those estimaoffted in the preceding 2, 4 and 8 weeks, and with a fall in the Spearman correlation coefficient at any preceding time interval.

INTERPRETATION

Because 1,5AG accurately detected a slight change in glycaemia without delay, it is suitable for use in monitoring for strict control of glycaemia, an important clinical goal.

Glucose-induced decrease in glutamate levels in ischemic human brain by in-vivo microdialysis

Glutamate is one of the principal neurotoxins in the pathogenesis of ischemic neuronal injury. Elevated glutamate levels in ischemia have been well documented in many animal stroke models. Recent work in humans also shows a similar trend. We have used our acute focal ischemic model of the human brain to study the response of glutamate levels by in vivo microdialysis during ischemia using two different perfusates. The addition of 30 mM of glucose to the perfusate attenuated the percentages of dialysate glutamate levels from 4.27 +/- 1.7 to 1.34 +/- 0.47 (P < 0.001) during partial ischemia and from 21.42 +/- 6.05 to 7.25 +/- 1.43 (P < 0.05) with total ischemia. The pre-ischemic values of glutamate were similar with the two perfusates. These results indicate that the ischemia-induced rise in glutamate is attenuated by exogenous glucose delivery in the human stroke model.

Organization and expression in Pseudomonas putida of the gene cluster involved in cephalosporin biosynthesis from Lysobacter lactamgenus YK90

The Lysobacter lactamgenus YK90 pcbAB gene encoding delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) synthetase is located immediately upstream of the pcbC gene in the same orientation in the gene cluster involved in cephalosporin biosynthesis. The pcbAB gene encodes a large polypeptide composed of 3722 amino acid residues with a molecular mass of 411593 Da. The predicted amino acid sequence has a high degree of similarity with those of known ACV synthetases from fungi and actinomycetes. Within the pcbAB amino acid sequence, three conserved and repeated domains of about 600 amino acids were identified. the domains also share a high degree of similarity with non-ribosomal peptide synthetases such as gramicidin synthetase 2 of Bacillus brevis. The pcbAB gene was expressed under the control of the lac promoter in Pseudomonas putida. Expression of the gene cluster involved in cephalosporin biosynthesis in P. putida led to the accumulation of beta-lactam antibiotics. Deletion analysis of an open-reading frame located between the cefE and cefD genes from the gene cluster revealed that it encoded deacetylcephalosporin C synthetase (cefF). From the results presented here and those of previous studies, the genes involved in cephalosporin biosynthesis in L. lactamgenus appear to be clustered in the order pcbAB-pcbC- cefE-cefF-cefD-bla in the same orientation within a 17-kb region of DNA.

Evaluation of monoaminergic neurotransmitters in the acute focal ischemic human brain model by intracerebral in vivo microdialysis

The release of neurotransmitters principally glutamate during cerebral ischemia has been extensively studied. It is well recognized that ischemia induced release of glutamate plays a key role in "excitotoxic" neuronal death. The role of monoaminergic neurotransmitters is however unclear. The purpose of this study was to evaluate the extracellular norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA) and serotonin (5-HT) under varied degrees of ischemia in the acute focal ischemic model of the human brain by in-vivo microdialysis. The ischemic response of these amines was correlated with the glutamate levels. Our study concludes that these amines and metabolites can be detected in the human "stroke" model. No marked fluctuations were noted in the levels of norepinephrine and DOPAC. However, significant changes to partial and total ischemia were noted in the extracellular levels of 5-HIAA and 5-HT. These compounds showed a dramatic increase with the onset of ischemia with higher detectable levels in the partial ischemic state in comparison to the total ischemic dialysate levels. The exact role played by the differential increase in the levels of 5-HT to the other catecholamines in the pathogenesis of ischemic neuronal damage remains unclear and warrants further study.

[A case of volatile solvent psychosis accompanied with multiple neurological and psychological symptoms]

A case of psychosis accompanied with variable symptoms induced by chronic volatile solvent inhalation is reported in this study. The patient was a 27-year-old male who had abused volatile solvents for 15 years, and was sent to the hospital because of a tonic-clonic seizure. Severe psychomotor excitement was observed on the first day and the 7th day after admission. After 10 days of admission, we observed visual transformation and hyperthermia, which suggested acute toxic symptoms due to a volatile solvent. Furthermore, symptoms such as incoherence, delusions of persecution, and catalepsy were also observed in this case. There have been few reports of multiple neurological and mental symptoms appearing in cases of volatile solvent psychosis. Although we sometimes experience cases of solvent abuse with acute mental symptoms and recurrent excitement after sedation, such symptoms are not always observed because of flashback in the strict sense. Therefore, careful early treatment should be employed to prevent 'secondary excitement'.

[A case of schistosomiasis suspected by circumoval precipitin test and diagnosed by rectal biopsy]

A forty-year-old female from Brazil was admitted to Teikyo Hospital because of easy fatigability, fullness of the abdomen and left hyochondralgia. She was anxious about Schistosoma mansoni infection, because three of her relatives died of the infection. Physical examinations revealed a tenderness at the left hypochondrium. Laboratory data showed no abnormal finding. No egg of S. mansoni was found in the stool. A circumoval precipitin test (COPT) with the serum showed a deposite around the egg. Enzyme-linked immunosorbent assay (ELISA) revealed the presence of antibody against S. mansoni in the serum. A colonoscopy showed no abnormal finding macroscopically. The rectal biopsy showed the existence of mild procitis. The diagnosis was made by finding the characteristic lateral-spined eggs in the biopsy specimens from the rectum. Treatment of 3 g of prazicantel per day for three days was started. She complained of mild nausea at the first dosing. A month later, another three-day-treatment was given. In the case where there are no eggs found in the stool, COPT and ELISA are usefull in detecting the disease, and colonoscopy is recommended in diagnosing the disease.

In-vivo microdialysis study of extracellular glutamate response to temperature variance in subarachnoid hemorrhage

Neurochemical changes may precede the development of clinical signs in neurological disease. Early identification of such changes may offer an opportunity to avoid or treat complications. Under experimental conditions, extracellular levels of glutamate and other amino acids can be monitored by in-vivo microdialysis in cerebral ischemia, head trauma and epilepsy. Data on the release of glutamate under ischemic conditions in humans are limited. There is no published data on the effects of temperature variation or other manipulations on the extracellular glutamate levels in humans. We report for the first time, the effects of changes in temperature on the extracellular cerebral glutamate levels as measured by in-vivo microdialysis, the dialysate being collected before, during and after cooling in four patients with subarachnoid hemorrhage. Three of the patients had in-vivo microdialysis carried out postoperatively. One patient underwent microdialysis three days prior to the surgical clipping of the aneurysm. In all patients, mild head cooling resulted in a significant decrease in extracellular glutamate levels. The effect of cooling was most apparent when the extracellular glutamate concentrations were high. In two patients, the extracellular glutamate levels increased sharply with fever but returned to normal once the temperature normalized. In vivo microdialysis can be used to measure extracellular glutamate and other neurotransmitters with minimal discomfort in awake humans. This technique offers a unique opportunity to monitor the neurochemistry in critically ill patients and it may aid in developing therapeutic intervention strategies to minimize undesired chemical responses.

Human REG family genes are tandemly ordered in a 95-kilobase region of chromosome 2p12

Reg, first isolated from a rat regenerating islet cDNA library, is expressed in regenerating islet beta-cells. Recently, it has been revealed that Reg and Reg-related genes constitute a multigene family, the Reg family. In human, the four REG family genes, i.e., REG 1 alpha, REG 1 beta, REG-related sequence (RS) and HIP/PAP, have so far been isolated. In this study, we analyzed YAC clones containing the four genes and performed two-color FISH to determine the map order of the genes. The human REG family genes are tandemly ordered in the 95-kbp DNA region of chromosome 2p12 as follows: 2cen-HIP/PAP-RS-REG I alpha-REG I beta-ptel.

Neuroprotective effects of lamotrigine in global ischemia in gerbils. A histological, in vivo microdialysis and behavioral study

A sudden surge in the release of glutamate is currently believed to be an important initiating step in neuronal damage due to an ischemic insult. In this experiment, we tested the efficacy of neuroprotection with lamotrigine, a novel antiepileptic drug that blocks voltage gated sodium channels and inhibits the ischemia-induced release of glutamate in the gerbil forebrain model of cerebral ischemia. The medication was administered 30 min before and 30 min after the insult in two groups of animals. Histological assessment of neuronal damage was evaluated at 7 and 28 days after the ischemic insult. Animals evaluated at 28 days also underwent behavioral testing. Microdialysis was used in the same model to study the response of ischemia-induced glutamate in saline treated controls versus animals treated with lamotrigine 20 min before the insult. There was highly significant neuronal protection in animals who were treated with lamotrigine either before or after the insult. Protection was seen both at 7 and 28 days after the insult. Behavioral testing also showed significantly better recovery in both sets of animals in comparison to the saline-treated group. Microdialysis confirmed a significant attenuation of the ischemia-induced glutamate surge when compared to the saline-treated animals. Our morphological, behavioral and microdialysis experiments show that lamotrigine offers significant neuroprotection from the effects of transient forebrain ischemia in gerbils. Neuroprotection with post-ischemic therapy probably depends on preserving the capacity of the sodium/calcium exchanger to reduce intracellular calcium concentrations or persistent 'toxicity' of glutamate in the reperfusion period on the already 'primed' injured neurons. These concepts need further study.

Clinical evaluation of vasospasm in subarachnoid haemorrhage by in vivo microdialysis

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Ethnic segregation of HTLV-I and HTLV-II carriers among South American native Indians

To investigate the genetic background of human T-cell leukemia virus type I (HTLV-I) and II (HTLV-II) carriers among South American native Indians, we analyzed HLA DRB1*-DQB1* haplotypes of the virus carriers from Andes highlands and Orinoco lowlands by the PCR-RFLP genotyping method. It was revealed that the HTLV-I-carrying Andes natives had one of the 5 HLA haplotypes: DRB1*-DQB1* 0403-0302, 0802-0402, 0901-0303, 1406-0302 and 0407-0302, and that the Orinoco HTLV-II carriers had one of the 3 HLA haplotypes: DRB1*-DQB1* 1402-0301, 1602-0301 and 0404-0302. The HLA haplotypes of Andes HTLV-I carriers and Orinoco HTLV-II carriers were mutually exclusive. The haplotypes associated with HTLV-I carriers were commonly found among the Andes Indians and Japanese, which is the known HTLV-I endemic population, while the haplotypes associated with HTLV-II carriers were specifically found among the Orinoco Indians and North American Indians, among whom HTLV-II is endemic. These results suggested that HLA haplotypes might be ethnically segregated among South American natives and might be involved in the susceptibility to HTLV-I and HTLV-II infections.