Affinity labeling displays the stepwise activation of ICE-related proteases by Fas, staurosporine, and CrmA-sensitive caspase-8

The activation of multiple interleukin-1beta converting enzyme-related proteases (caspases) in apoptotic mammalian cells raises questions as to whether the multiple active caspases have distinct roles in apoptotic execution as well as how these proteases are organized in apoptotic signaling pathways. Here we used an affinity-labeling agent, YV(bio)KD-aomk, to investigate the caspases activated during apoptotic cell death. YV(bio)KD-aomk identified six distinct polypeptides corresponding to active caspases in Fas-stimulated Jurkat T cells. On staurosporine treatment, four polypeptides were detected. Competition experiments showed that the labeled caspases have distinct substrate preferences. Stepwise appearance of the labeled caspases in each cell death event was consistent with the view that the activated caspases are organized into protease cascades. Moreover, we found that stepwise activation of caspases similar to that induced by Fas ligation is triggered by exposing non-apoptotic Jurkat cell extracts to caspase-8 (MACH/FLICE/Mch5). Conversely, CrmA protein, a viral suppressor of Fas-induced apoptosis, inhibited the protease activity of caspase-8. Overall, these findings provide evidence that caspase-8, a CrmA-sensitive protease, is responsible for initiating the stepwise activation of multiple caspases in Fas-stimulated cells.

Kinins contribute to the improvement of insulin sensitivity during treatment with angiotensin converting enzyme inhibitor

Although angiotensin converting enzyme inhibitors and alpha 1-blockers have been reported to improve insulin sensitivity, their mechanisms of action have not been elucidated. To investigate the role of kinins in insulin sensitivity, we treated 4-week-old spontaneously hypertensive rats with either an angiotensin converting enzyme inhibitor (enalapril), an alpha 1-blocker (doxazosin), or an angiotensin II antagonist (losartan) for 3 weeks. A control group received no drugs. In addition, 18 rats treated with enalapril or doxazosin received a simultaneous administration of a kinin antagonist (Hoe 140). Glucose clamp testing was performed in each group. Enalapril (128 +/- 1 mmHg) and doxazosin (132 +/- 2 mmHg) decreased mean blood pressure compared with control levels (148 +/- 1 mmHg) (P < .01). The glucose requirement for the clamp test during the administration of enalapril (25.8 +/- 0.5 mg/kg per minute) or doxazosin (28.6 +/- 0.7 mg/kg per minute) was higher than that of the control group (19.8 +/- 0.5 mg/kg per minute) (P < .05). Although Hoe 140 did not alter the glucose requirement of doxazosin (27.8 +/- 0.5 mg/kg per minute), it decreased that of enalapril (22.6 +/- 0.9 mg/kg per minute) (P < .05) without affecting the changes in mean blood pressure induced by enalapril. In addition, losartan decreased mean blood pressure but did not affect the glucose requirement. Thus, the improvement in insulin sensitivity produced by an angiotensin converting enzyme inhibitor is mostly dependent on kinins but not on angiotensin II antagonism, and an alpha 1-blocker improves insulin sensitivity irrespective of kinins.

Dual-loop intra-atrial reentry in humans

BACKGROUND

Dual-loop atrial reentrant tachycardias have not been clinically described.

METHODS AND RESULTS

Five patients (3 men, 2 women; mean age, 48+/-16 years) were studied 24+/-15 years after surgical closure of an ostium secundum atrial septal defect for drug-resistant atrial tachycardia. Complete tachycardia mapping was performed in the right atrium with multipolar catheters and a 3-dimensional electroanatomic mapping system (Biosense), followed by linear radiofrequency ablation of the narrowest part of each complete loop. Six tachycardias with a typical flutter morphology, a cycle length of 262+/-40 ms, and a superior f-wave axis (-77+/-11 degrees ) were mapped, 4 with a Biosense map including 106+/-32 points. Five figure-8 tachycardias had a counterclockwise loop around the tricuspid valve sharing a common anterior channel with a clockwise loop around the lateral atriotomy scar. One tachycardia was thought to have 2 counterclockwise loops around the same obstacles. Radiofrequency delivery in the cavotricuspid isthmus in each case transformed the tachycardia without any pause in a different morphology tachycardia with an inferior P-wave axis (50+/-42 degrees ) and nearly the same cycle length (272+/-39 ms) but with the periatriotomy loop alone. This arrhythmia required ablation of a second isthmus: between the lower end of the atriotomy and the inferior vena cava in 4 and the superior tricuspid annulus in 1. After a follow-up of 19+/-6 months, there were no recurrences.

CONCLUSIONS

Figure-8 double-loop tachycardias mimicking the ECG pattern of a common atrial flutter occur in some patients after a surgical atriotomy. Ablation of 1 loop produces a sudden transformation to a new reentrant tachycardia formed of the remaining loop that requires ablation at a second isthmus.

A new technique for monitoring the behaviour of free-ranging Adelie penguins

Measurement of the time allocation of penguins at sea has been a major goal of researchers in recent years. Until now, however, no equipment has been available that would allow measurement of the aquatic and terrestrial behaviour of an Antarctic penguin while it is commuting between the colony and the foraging grounds. A new motion detector, based on the measurement of acceleration, has been used here in addition to current methods of inferring behaviour using data loggers that monitor depth and speed. We present data on the time allocation of Adelie penguins (Pygoscelis adeliae) according to the different types of behaviours they display during their foraging trips: walking, tobogganing, standing on land, lying on land, resting at the water surface, porpoising and diving. To illustrate the potential of this new technique, we compared the behaviour of Adelie penguins during the chick-rearing period in a fast sea-ice region and an ice-free region. The proportion of time spent standing, lying on land and walking during foraging trips was greater for penguins in the sea-ice region (37.6+/−13.3% standing, 21.6+/−15.6% lying and 5.9+/−6.3% walking) than for those in the ice-free region (12.0+/−15.8 % standing, 0.38+/−0.60% lying and 0 % walking), whereas the proportion of time spent resting at the water surface and porpoising was greater for birds in the ice-free region (38.1+/−6.4% resting and 1.1+/−1.1% porpoising) than for those in the sea-ice region (3.0+/−2.3% resting and 0% porpoising; means +/− s.d., N=7 for the sea-ice region, N=4 for the ice-free region). Using this new approach, further studies combining the monitoring of marine resources in different Antarctic sites and the measurement of the energy expenditure of foraging penguins, e.g. using heart rates, will constitute a powerful tool for investigating the effects of environmental conditions on their foraging strategy. This technique will expand our ability to monitor many animals in the field.

Melanotropin and corticotropin are encoded on two distinct genes in the lamprey, the earliest evolved extant vertebrate

In the lamprey, which is a member of the oldest extant class of vertebrates, the agnathans, melanotropins (MSH) and corticotropin (ACTH) were found to be encoded on two distinct genes. In all other vertebrates, a single precursor gene, proopiomelanocortin (POMC), encodes MSH and ACTH, as well as beta-endorphin (END). Two different cDNAs were cloned from a lamprey pituitary lambda gt11 cDNA library using antisera against lamprey MSH-B and ACTH(1-16). One cDNA encoded MSH-B, MSH-A and beta-END, while the other cDNA encoded nasohypophysial factor (NHF), ACTH and a different beta-END, but not MSH-A and MSH-B. Northern blot analysis demonstrated that in the adult lamprey pituitary, genes for MSH and ACTH are expressed in the pars intermedia (PI) and pars distalis (PD), respectively.

Neutralization of vascular endothelial growth factor prevents collagen-induced arthritis and ameliorates established disease in mice

Vascular endothelial growth factor (VEGF) is implicated in the pathogenesis of inflammatory joint diseases, including rheumatoid arthritis (RA). To determine the importance of this cytokine in vivo, the effect of administering VEGF-neutralizing antibodies to mice with collagen-induced arthritis (CIA), which has many immunological and pathological similarities to human RA, has been investigated. Either saline, normal rabbit immunoglobulin or anti-human VEGF121 rabbit polyclonal antibody was administered to mice subcutaneously either before the onset of arthritis or after the establishment of clinical disease. Anti-VEGF antibody administered prior to disease onset significantly delayed the development of arthritis and decreased clinical score and paw thickness as well as histological severity. On the other hand, the frequency of occurrence of disease compared to either the control group administered saline or normal rabbit immunoglobulin was not altered. Anti-VEGF antibody also significantly ameliorated clinical and histological parameters even when administered after disease onset. These results indicate a possible therapeutical potential for anti-VEGF treatment in human arthritis.

Adenosine-sensitive atrial reentrant tachycardia originating from the atrioventricular nodal transitional area

INTRODUCTION

Atrial tachycardia shows wide variations in its electrophysiologic properties and sites of origin. We report an atrial tachycardia with ECG manifestations and electrophysiologic characteristics similar to an atypical form of AV nodal reentrant tachycardia (AVNRT).

METHODS AND RESULTS

This supraventricular tachycardia was observed in 11 patients. It was initiated by atrial extrastimulation with an inverse relationship between the coupling interval of an extrastimulus and the postextrastimulus interval. Its induction was not related to a jump in the AH interval, and its perpetuation was independent of conduction block in AV node. Ventricular pacing during tachycardia demonstrated AV dissociation without affecting the atrial cycle length. A very small dose of adenosine triphosphate (mean 3.9 +/- 1.2 mg) could terminate the tachycardia. The earliest atrial activation during tachycardia was recorded at the low anteroseptal right atrium with a different intra-atrial activation sequence from that recorded during ventricular pacing, where the tachycardia was successfully ablated in 9 of 10 attempted patients. Bidirectional AV nodal conduction remained unaffected after successful ablation.

CONCLUSION

There may be an entity of adenosine-sensitive atrial tachycardia probably due to focal reentry within the AV node or its transitional tissues without involvement of the AV nodal pathways. This tachycardia can be ablated without disturbing AV nodal conduction from the right atrial septum.

N-methylation of dopamine-derived 6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, (R)-salsolinol, in rat brains: in vivo microdialysis study

N-Methylation of (R)-1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [(R)-salsolinol] derived from dopamine was proved by in vivo microdialysis study in the rat brain. The striatum was perfused with (R)-salsolinol and N-methylated compound was identified in the dialysate using HPLC and electrochemical detection with multichanneled electrodes. N-Methylation of (R)-salsolinol was confirmed in three other regions of the brain, the substantia nigra, hypothalamus, and hippocampus. In the substantia nigra, the amount of N-methylated (R)-salsolinol was significantly larger than in the other three regions. These results indicate that around dopaminergic neurons, particularly in the substantia nigra, (R)-salsolinol was methylated into N-methyl-(R)-salsolinol, which has a chemical structure similar to that of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, the selective dopaminergic neurotoxin. N-Methylation of tetrahydroisoquinolines and beta-carbolines have already been proven to increase their toxicity to dopaminergic neurons and N-methylation might be an essential step for these alkaloids to increase their toxicity. On the other hand, after perfusion of (R)-salsolinol, release of dopamine and 5-hydroxytryptamine was observed and inhibition of monoamine oxidase was indicated. (R)-Salsolinol and its derivatives may be candidates for being dopaminergic neurotoxins.

A pivotal role of IL-12 in Th1-dependent mouse liver injury

Intravenous injection of Propionibacterium acnes and lipopolysaccharide (LPS) with a 7 day interval caused CD4+ T cell-dependent severe liver injury in the C57BL/6 (H-2b) mouse strain. In contrast, BALB/c (H-2d) mice were resistant to P. acnes and LPS-induced liver injury. The different susceptibilities of the two mouse strains to liver injury appeared to be closely correlated with their different abilities to produce IFN-gamma after P. acnes priming. Namely, the sensitive C57BL/6 mouse strain produced a significant level of IFN-gamma 7-10 days after P. acnes injection, whereas no significant amount of serum IFN-gamma was detected in the resistant BALB/c mouse strain. The important role of IFN-gamma in liver injury was demonstrated from the finding that in vivo administration of anti-IFN-gamma mAb abrogated P. acnes and LPS-induced liver injury in C57BL/6 mice. Moreover, it was demonstrated that in vivo administration of recombinant IL-12, a key cytokine for the induction of IFN-gamma, into mice induced P. acnes and LPS-induced liver injury in the resistant BALB/c mouse strain. Conversely, in vivo administration of anti-IL-12 mAb blocked the development of liver injury in the sensitive C57BL/6 mouse strain. Moreover, it was demonstrated that the failure of the induction of liver injury in BALB/c mice appeared to be derived from the lack of expression of IL-12 at the local site of liver in P. acnes-primed mice. These results strongly indicated that endogenous IL-12, which stimulates Th1-dominant cellular immunity and IFN-gamma production, may be an essential cytokine on the course of T cell-dependent liver injury.

Development and validation of a salmon growth hormone radioimmunoassay

A highly specific and sensitive radioimmunoassay (RIA) for the measurement of plasma and pituitary growth hormone (GH) levels in salmonid fishes was developed using an anti-serum raised in rabbit against chum salmon (Oncorhynchus keta) GH (sGH). Pituitary extracts and plasma from chum, coho, masu, and amago salmon, and from rainbow trout and Japanese charr, all exhibited displacement curves parallel to the sGH standard. Samples from the eel, carp, goldfish, and tilapia, as well as plasma from hypophysectomized chum salmon and rainbow trout, all showed negligible cross-reactivity. None of the mammalian or teleostean GH or prolactin preparations tested cross-reacted with the antibody in the assay system. RIA sensitivity was 0.6 ng sGH/ml of plasma when 100 microliter of plasma was employed. Intra- and interassay coefficients of variation were 3.9 and 4.1%, respectively. Plasma GH levels of the mature chum salmon caught in Otsuchi Bay were highly variable, especially in females (20.2 +/- 8.2 ng/ml) as compared with males (16.0 +/- 1.1 ng/ml), and there was no significant change after transfer to fresh water. Whereas there was no change in plasma GH levels in males kept in seawater, the levels in females increased with time in close correlation with the increase in plasma chloride.

Diagnosis of familial amyloidotic polyneuropathy by recombinant DNA techniques

An amino acid substitution of Met for Val at position 30 of plasma prealbumin is known to be closely related to heredo-familial amyloidotic polyneuropathy(FAP). As a first step in development of a direct method for diagnosis of the disease, cDNA for normal human prealbumin was cloned and its nucleotide sequence was determined. Our results showed that the nucleotide substitution responsible for the Val----Met change results in formation of new restriction sites for BalI and NsiI. By Southern blot hybridization analysis, the expected restriction sites were actually detected in the prealbumin locus of patients. Thus, a method was developed for diagnosis of the disease presymptomatically and prenatally.

Artificial pulmonary surfactant inhibited by proteins

With a pulsating bubble surfactometer we assessed the ability of various agents, fibrinogen, human serum, albumin, and a 55,000-dalton serum protein, to interfere with the surface activity of Surfactant TA. From a highest final protein concentration of 4 mg/ml the potential inhibitors were diluted down to 0.125 mg/ml in six steps, and each concentration was evaluated together with two final phospholipid concentrations, 6.25 and 1.25 mg/ml, of the surfactant preparation. The strongest inhibiting action was exerted by fibrinogen, followed by human serum and the 55,000-dalton serum protein; the weakest inhibitor was albumin. Bilirubin, when added in an amount of 1.73 mg/100 ml dissolved in human serum, significantly (P less than 0.001) augmented the inhibition over that exerted by human serum alone. Adsorption rate, as reflected in the mean value of surface tension 2 and 10 s after creation of a bubble, not pulsating, was seriously affected by each of the protein-containing inhibitors in concentrations exceeding 1 mg/ml. Surface tension was raised significantly when the pulsating bubble was at maximal and minimal size. The effect was dose dependent. At maximal size it showed no tendency to disappear during the 10-min recording, but at minimal bubble size the inhibition gradually diminished. We conclude that proteins present in the airways may seriously interfere with the activity of Surfactant TA.

Altemicidin, a new acaricidal and antitumor substance. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties

Screening of new insecticidal and acaricidal antibiotics was carried out with reference to anti-brine shrimp activity from actinomycete strains isolated from marine environments. Of 200 actinomycete isolates, one isolate was found to produce a new substance, altemicidin. The strain was isolated from sea mud collected at Gamo, Miyagi Prefecture, Japan, and identified as Streptomyces sioyaensis SA-1758. Altemicidin was purified by Diaion CHP-20P and Sephadex LH-20 column chromatographies. The molecular formula was determined as C13H20N4O7S by elemental analysis, MS and 13C NMR spectrum. Altemicidin showed not only acaricidal activity but also antitumor activity. The compound showed no antimicrobial activity except the inhibitory activity to Xanthomonas strains.

CFTR-dependent membrane insertion is linked to stimulation of the CFTR chloride conductance

We examined the relation between Cl current (Icl) stimulation and cell membrane capacitance (Cm) when cystic fibrosis transmembrane conductance regulator (CFTR) was expressed in Xenopus oocytes. ICl and Cm increased in parallel when oocytes expressing CFTR were stimulated by forskolin (10 microM) and 3-isobutyl-1-methylxanthine (1 mM). The adenosine 3',5'-cyclic monophosphate (cAMP)-induced increase in surface area detected by Cm was confirmed by morphometry in the same oocytes used for the electrical recordings. These increases in ICl and Cm were reversible and were absent from control oocytes not injected with CFTR cRNA. The time to reach peak ICl lagged slightly behind the peak in Cm. ICl was varied by altering CFTR expression level or agonist dose or by expressing different CFTR mutants. In all cases, there was a close correlation between ICl and Cm, and the kinetics of ICl and Cm stimulation were more rapid the larger the magnitude of the stimulated current. The Cm-ICl relation for wild-type CFTR saturated, consistent with a limited capacity of cells to increase their surface area. These results indicate that stimulation of the CFTR ICl is linked closely to increases in membrane area. This suggests that CFTR is present in the membrane vesicles whose insertion is stimulated by cAMP. The contents of these vesicles may provide a link between activation of CFTR and its cAMP-dependent regulation of other channels.

Angiogenic factors in moyamoya disease

BACKGROUND AND PURPOSE

We previously reported that the level of basic fibroblast growth factor (bFGF) is high in cerebrospinal fluid (CSF) taken from patients with moyamoya disease. The present study investigated the levels of other angiogenic growth factors in the CSF of moyamoya patients and the clinical significance of bFGF in moyamoya disease.

METHODS

The levels of bFGF, interleukin-8, platelet-derived growth factor, transforming growth factor-beta, endothelial growth factor, and vascular endothelial cell growth factor in CSF, taken from 38 patients with moyamoya disease and 16 patients with atherosclerotic occlusive disease (control group), were measured by an enzyme-linked immunosorbent assay. We analyzed the correlation between the level of bFGF and the clinical factors of age, onset pattern, development of neovascularization, and cerebral circulation.

RESULTS

The CSF of moyamoya patients contained a high concentration of bFGF to a significant (P < .05) extent. The bFGF level was apparently elevated in the patients in whom neovascularization from indirect revascularization, such as encephaloduroarteriosynangiosis, was well developed (P < .01). A linear correlation between the values of bFGF and cerebral vascular response to acetazolamide (r = .7; P < .05) was revealed. The other angiogenic factors were not significantly high compared with the control group.

CONCLUSIONS

The elevation of bFGF in moyamoya disease seems to be specific and is not related simply to cerebral ischemia. Clinically, the bFGF level is a useful indicator to predict the efficacy of indirect revascularization after surgery.

Spinal cord morphology and pathology in ossification of the posterior longitudinal ligament

We analysed nine autopsy cases of ossification of the posterior longitudinal ligament (OPLL) to elucidate the relationship between morphology and pathology of the spinal cord. The cross-sectional shape of the spinal cord at the most severely affected segment was classified into two categories: boomerang (convex lateral surfaces and concave anterior surface) and triangular (angular lateral surfaces and flat anterior surface). In the cases with a boomerang shape, even when the compression was severe, major pathological changes were restricted to the grey matter and the white matter was relatively well preserved. No secondary descending degeneration of the lateral columns was seen, and ascending degeneration of the posterior column was restricted to the fasciculus cuneatus whose fibres were derived from the affected segments. In the cases with a triangular shape, pathological changes were more severe, both white matter and grey matter were involved, and only the anterior columns were free of pathological changes. There were severe pathological changes over more than one segment, and both descending degeneration of the lateral pyramidal tracts and ascending degeneration of the posterior column, including the fasciculus gracilis, were observed. The transverse area of the spinal cord was > 60% of normal in most of the cases with a boomerang shape, but it was reduced to < 60% of normal in more than one segment in the cases with a triangular shape. The compression ratio of the spinal cord (sagittal diameter/transverse diameter x 100%) was not related to pathological changes. In conclusion, a triangular-shaped spinal cord with transverse area of < 60% of normal in more than one segment appeared to be associated with severe and irreversible pathological changes in cases of OPLL.

Growth rates of primary and metastatic lesions of renal cell carcinoma

BACKGROUND

The natural history and growth rate of renal cell carcinoma (RCC) have not yet been determined. The growth rates of primary lesions in incidentally found RCC were compared with those of metastatic lesions.

METHODS

Sixteen patients who did not receive immediate surgical treatment for renal solid masses that were later proven to be RCC were reviewed retrospectively. All primary lesions of the 16 patients were found incidentally. For comparison, metastatic lesions were evaluated in another 16 patients with RCC. Of these, 11 underwent surgical treatment for the primary lesions.

RESULTS

The growth rates of primary and metastatic lesions of RCC varied. They ranged from 0.10 to 1.35 cm/year for primary lesions and from 0.08 to 7.87 cm/year for metastatic lesions. The growth rate of primary lesions of incidentally found RCC was lower than that of metastatic lesions (P = 0.0159). The initial tumor diameter and pathological grade did not affect the growth rate of the primary lesion of incidentally found RCC. However, a close correlation was found between the growth rate of metastatic lesions and the pathological grade of the primary lesion in patients with metastasis.

CONCLUSIONS

The growth rate of incidentally found RCC varied. Some patients with the disease may be candidates for 'watchful waiting' when an immediate surgical treatment is not indicated, but they should be selected with great caution.

Isolation and properties of chum salmon prolactin

A highly purified prolactin (PRL) was isolated from the chum salmon pituitary by extraction with acid acetone, gel filtration on Sephadex G-25 and ion-exchange chromatography on CM-Sephadex C-25 with a yield of 1 mg/g of wet tissue. It was 10-15 times more potent than ovine PRL in sodium-retaining activity for juvenile rainbow trout adapted to 50% seawater. The salmon PRL emerged as a single and symmetrical peak on Sephadex G-100 with Ve/Vo = 2.0. Polyacrylamide gel electrophoresis revealed only one band at pH 4.3, whereas no band was seen at pH 7.5. The isoelectric point was estimated to be 10.3 by gel electric focusing. The circular dichroism spectrum of the salmon PRL was similar to that of tilapia PRL, showing an alpha-helix content of 50%. The salmon PRL had a molecular weight of 23,400 daltons by gel filtration and 22,300 daltons by sodium dodecyl sulfate gel electrophoresis, with a single NH2-terminal residue, isoleucine, and a single COOH-terminal residue, half-cystine. In the sequence comparison with those of mammalian PRLs and growth hormones, the clusters of invariant residues were found in both terminal regions, although the disulfide at NH2-terminal of mammalian PRLs was missing. Specific salmon PRL antisera were prepared in rabbits giving a precipitin reaction against the salmon PRL and a pituitary extract of tilapia in agar diffusion but no cross reaction with purified mammalian PRLs. The antibody was localized specifically in PRL cells of the chum salmon pituitary.

The cerebrospinal fluid in patients with moyamoya disease (spontaneous occlusion of the circle of Willis) contains high level of basic fibroblast growth factor

The level of basic fibroblast growth factor (bFGF) in cerebrospinal fluid (CF) was measured by an EIA in 15 patients with moyamoya disease, in 11 patients with atherosclerotic occlusive disease, and in 8 patients with spinal disc disease. In the moyamoya patients, bFGF was found in 13 out of 15 CF samples with a mean value of 101 pg/ml. However, bFGF was detected in only 4 out of 11 patients with atherosclerotic disease with a mean of 8 pg/ml. In all the patients with disc disease, bFGF was not detected. The elevated level of bFGF may play a crucial role in the pathogenesis of moyamoya disease.

Mid-term follow-up of endocardial biventricular pacing

Biventricular (BV) pacing is a promising treatment of end-stage heart failure. This article describes our experience with a strictly endocardial BV pacing system in patients with severe congestive heart failure. Three women and eight men (age 65 +/- 9 years) with drug-resistant end-stage CHF underwent implantation of an endocardial BV pacing system. In the first seven patients, the left ventricular lead was placed via a combined femoral and internal jugular approach. In the last four patients, the transseptal puncture was directly performed via the right internal jugular vein with a dedicated kit. The procedure was successful in all 11 patients. The acute left ventricular and BV thresholds were 1.3 +/- 0.6 V and 2.4 +/- 1 V, respectively. The QRS duration decreased from 214 +/- 57 to 176 +/- 25 ms. A functional improvement was noted in ten patients with a decrease in mean NYHA functional class from 3.7 +/- 0.5 before, to 2.6 +/- 0.9 after system implantation. A significant decrease in pulmonary capillary wedge pressure and increase in cardiac output were measured in eight patients. During follow-up, four patients died from CHF (n = 3) or ventricular fibrillation (n = 1). Under oral anticoagulation, no thromboembolic event was observed but one transient ischemic attack occurred in one patient whose anticoagulation was interrupted. Endocardial BV pacing is technically feasible and appears safe, though further studies are needed before it is used on a longer scale.

A pitfall in the surgery of a recurrent aneurysm after coil embolization and its histological observation: technical case report

OBJECTIVE AND IMPORTANCE

This case report details the unexpected surgical difficulty encountered in treating a recurrent aneurysm after coil embolization and presents the histological findings of the resected aneurysm. This is only the second reported case of histological description of an aneurysm after coil embolization in a human.

CLINICAL PRESENTATION

A 60-year-old woman experienced a 3-month history of chronic headache. Neuroimaging studies demonstrated a 2-cm anterior communicating artery aneurysm. The aneurysm was treated with a two-stage endovascular coil embolization, resulting in almost complete occlusion of the aneurysm. A cerebral angiogram at 6-month follow-up demonstrated slight refilling of the aneurysm, and angiography at 18 months showed a marked increase in the size of the small remnant. Therefore, the patient was referred for direct surgical repair of the aneurysm.

INTERVENTION

The distal aneurysm dome, which had been packed with the coils and thrombus, was resected under temporary arterial trapping. An intra-aneurysmal endarterectomy was required, because the aneurysm wall developed intimal dissection that extended to the orifices of afferent and efferent arteries. The aneurysm was then obliterated with multiple clips, reconstructing the patent vessel lumen. However, the patient awoke from surgery with left hemiparesis. A postoperative angiogram disclosed occlusion of the right anterior cerebral artery. An histological study of the thrombosed aneurysm showed that the luminal surface of thrombus was not lined by endothelium.

CONCLUSION

This case demonstrated not only the limited efficacy of coil embolization treatment for wide-necked aneurysms but also the potential difficulty in the direct surgical repair for such recurrent aneurysms.

Molecular characterization and heterologous expression of the gene encoding a low-molecular-mass endoglucanase from Trichoderma reesei QM9414

We have isolated the genomic and cDNA clones encoding EG III (a low-molecular-mass endo-beta-1,4-glucanase) gene from Trichoderma reesei QM9414. The nucleotide sequence of the cDNA fragment was verified to contain a 702-bp open reading frame that encodes a 234-amino-acid propeptide. The deduced protein sequence has significant homologies with family H endo-beta-1,4-glucanases. The 16-amino-acid N-terminal sequence was shown to function as a leader peptide for possible secretion. Northern blot analysis showed that the EG III gene transcript, with a length of about 700 bp, was expressed markedly by cellulose but not by glucose. The protein has been expressed as a mature form in Escherichia coli and as secreted forms in Saccharomyces cerevisiae and Schizosaccharomyces pombe under the control of tac, alcohol dehydrogenase (ADH1), and human cytomegalovirus promoters, respectively. The S. cerevisiae and Schizosaccharomyces pombe recombinant strains showed strong cellulolytic activities on agar plates containing carboxymethyl cellulose. The E. coli strain expressed small amounts of EG III in an active form and large amounts of EG III in an inactive form. The molecular masses of the recombinant EG IIIs were estimated to be 25, 28, and 29 kDa for E. coli, S. cerevisiae, and Schizosaccharomyces pombe, respectively, by immunoblot analysis following sodium dodecyl sulfate-polyacryl-amide gel electrophoresis. Parts of the yeast recombinant EG IIIs decreased their molecular masses to 25 kDa after treatment with endoglycosidase H and alpha-mannosidase, suggesting that they are N glycosylated at least partly.

Interleukin-6 in renal cell carcinoma

We studied interleukin-6 production in 4 human renal cell carcinoma cell lines and measured the serum level in 71 patients with renal cell carcinoma, thus, clarifying a relationship between interleukin-6 secretion and an occurrence of the paraneoplastic syndrome in the carcinoma. Interleukin-6 was produced by 3 cell lines and detected in 25% of the patients. The level of interleukin-6 did not directly correlate with tumor volume and the differentiation grade of the carcinoma. However, the positive rate increased with progression of the stage. The serum level affected the 5-year survival of patients without distant metastasis. When serum interleukin-6 was elevated patients had a significantly higher frequency of unexplained fever and an elevation of acute phase proteins. These results suggest that some renal cell carcinomas can produce interleukin-6 and this cytokine is responsible for several paraneoplastic syndromes in the carcinoma.

Isolation of a distinct class of gain-of-function SHP-2 mutants with oncogenic RAS-like transforming activity from solid tumors

SHP-2 protein tyrosine phosphatase plays an important role in activation of the RAS-dependent signaling. Gain-of-function mutations in the PTPN11 gene, which encodes SHP-2, have been found in the leukemia-prone developmental disorder Noonan syndrome as well as sporadic childhood leukemias, indicating that SHP-2 is a bona fide human oncoprotein. However, the role of SHP-2 mutations in non-hematological malignancies remains obscure. Here, we screened for PTPN11 mutations in primary solid tumors and identified a 1520C>A mutation that causes threonine-507 to lysine (T507K) substitution in the phosphatase domain of SHP-2 in a case of hepatocellular carcinoma. T507K SHP-2 exhibited altered substrate specificity with slightly elevated basal phosphatase activity. Upon expression in NIH3T3 cells, T507K SHP-2 induced transformed foci, which was not observed with wild type, Noonan-specific or leukemia-specific SHP-2. Furthermore, NIH3T3 cells transformed by T507K SHP-2 showed anchorage-independent growth and developed tumors in nude mice. These results indicate that quantitative and/or qualitative alteration in phosphatase activity determines the transforming potential as well as target cell/tissue spectrum of individual SHP-2 mutants as oncoproteins. Although rare in solid tumors, the identified T507K SHP-2 represents a distinct class of SHP-2 mutants with oncogenic RAS-like transforming activity, which could contribute to the development of solid tumors.

Mitochondrial DNA deletions in inherited recurrent myoglobinuria

We describe two brothers with inherited recurrent exertional myoglobinuria and alcohol intolerance associated with distinct morphological abnormalities of muscle mitochondria and multiple deletions of muscle mitochondrial DNA. Patient 1 (26 years old) and Patient 2 (21 years old) had recurrent episodes of myoglobinuria provoked by strenuous exercise or alcohol intake, from the age of 18 years. Although their serum lactate and pyruvate levels were normal at rest, they were significantly elevated by aerobic exercise. Histochemistry of their biopsied limb muscles showed ragged-red fibers and cytochrome c oxidase-negative fibers as well as degenerating and regenerating fibers. Electron microscopy showed pronounced accumulation of abnormal mitochondria containing paracrystalline inclusions and moderate increases of glycogen particles. The enzyme activities of the electron-transfer complexes in the isolated muscle mitochondria of Patient 2 were within normal ranges. Southern blot analysis revealed multiple deletions of mitochondrial DNA, some of which were common between the patients. Polymerase chain reaction of their muscle mitochondrial DNA detected multiple abnormal fragments indicating mitochondrial DNA deletions. We propose that a defect of the mitochondrial energy-transducing system due to multiple mitochondrial DNA deletions is a novel genetic cause of inherited recurrent myoglobinuria.