Gene analysis and enzymatic properties of thermostable beta-glycosidase from Pyrococcus kodakaraensis KOD1

A beta-glycosidase with broad substrate specificity was identified from a hyperthermophilic archaeon, Pyrococcus kodakaraensis KOD1. The gene encoding beta-glycosidase (Pk-gly) consists of 1449 nucleotides corresponding to a polypeptide of 483 amino acids. The protein showed similarity with other beta-glycosidases from family-1 glycosyl hydrolases, in particular, it showed high identity to beta-mannosidase from P. furiosus (55.7%), beta-glycosidase from Sulfolobus solfataricus (42.7%) and beta-glucosidase from P. furiosus (41.9%). The cloned gene was expressed in Escherichia coli and the recombinant protein was purified. The beta-glycosidase showed optimal activity at pH 6.5 and at an extremely high temperature of 100 degrees C, and had a half-life of 18 h at 90 degrees C. The beta-glycosidase hydrolyzed various pNp-beta-glycopyranosides, with kcat K(m) values in the order of pNp-beta-glucopyranoside = pNp-beta-mannopyranoside > pNp-beta-galactopyranoside > pNp-beta-xylopyranoside. pNp-beta-mannopyranoside was the substrate exhibiting the lowest K(m) value [0.254 mM] with a kcat K(m) ratio comparable to that of pNp-beta-glucopyranoside. This substrate specificity was distinct from previously reported beta-glycosidases. We observed that the region in PK-Gly corresponding to the fifth alpha-helix and beta-strand region of beta-glycosidase from S. solfataricus, which constitutes a large portion of the channel for substrate incorporation, displayed a chimeric structure, with the N-terminal region similar to beta-glycosidases and the C-terminal region similar to beta-mannosidases. An exo-type hydrolytic activity and transglycosylation activity were also observed towards cellooligomers.

Living-Related Small Bowel Transplantation: Two Cases Experiences

We have recently performed living-related small bowel transplantation for 2 patients. The first patient was a 14-year-old boy with total parenteral nutrition (TPN)-dependent short-bowel syndrome associated with hypoganglionosis of the entire intestine. He received a bowel graft from his 43-year-old mother. The second patient was a 27-year-old woman, who had massive enterectomy due to volvulus and developed vitamin deficiencies and severe metabolic disorders as a result of long-term TPN. She underwent living-related bowel transplantation from her 57-year-old mother. Blood types were ABO identical, cytotoxic cross matches were negative, and cytomegalovirus statuses were positive-to-positive in both cases. Up to one third of the donor bowel was harvested from the donor distal ileum more than 30 cm away from the ileocecal valve. The graft vessels were connected to infrarenal aorta, and inferior vena cava. The immunosuppressive regimen consisted of daclizumab, tacrolimus, and steroid. The graft surveillance was accomplished using zoom endoscopy and mucosal biopsy. The first patient developed progressive acute cellular rejection (ACR) on the 9th postoperative day (POD)-9 requiring OKT-3 therapy, which was effective. Two months after transplantation, he was weaned from TPN, tolerating oral intake with a fully functioning graft. The second patient experienced no episode of ACR and was weaned off TPN on POD-29 with a functioning graft. Her metabolic disorder dramatically improved after bowel transplantation. Both donors had no complication and were discharged from the hospital on POD-10. Living-related bowel transplantation is an extreme option of treatment for patients with short-bowel syndrome.

The colon displays an absorptive capacity of tacrolimus

PURPOSE

In our previous study, blood levels of orally administered tacrolimus were significantly higher in short bowel piglets than in control animals. It has been reported that the blood levels of tacrolimus are influenced by the metabolic activity of intestinal CYP3A4. If tacrolimus may be absorbed in the colon, direct administration of drug into this organ might be useful to augment bioavailability since the expression of CYP3A4 is low at this site. In the present study we evaluated the absorptive capacity of tacrolimus in the colon.

MATERIALS AND METHODS

Piglets were divided into four groups: groups 1 and 2 were controls (n = 11 and 3, respectively); group 3 underwent resection of the entire small intestine (n = 8); and group 4 had a catheter placed in the cecum (n = 4). In groups 1 and 3, tacrolimus was administered orally; in group 2 it was given intravenously; and in group 4 it was injected into cecum through the catheter from postoperative days 3 to 7. On day 7, blood samples were obtained for drug measurements to calculate the area under the concentration time curve (AUC) values.

RESULTS

The trough level and AUC values of tacrolimus in group 4 as well as in group 3 were significantly higher than those in group 1. In Group 4 animals showed a 60-minute time to peak concentration.

CONCLUSIONS

Tacrolimus is absorbed by the colon. Since the blood levels were not influenced by the metabolic activity in the graft bowel, direct administration of tacrolimus into the colon might be useful in small intestinal transplantation.

The expression of intestinal CYP3A4 in the piglet model

PURPOSE

In our previous study, the blood levels of tacrolimus were higher in the short bowel and small bowel transplantation models than those in controls. Metabolism by intestinal cytochrome p450 3A4 (CYP3A4) has been reported to influence the blood level of orally administered tacrolimus. We performed immunohistochemistry to examine the localization of intestinal CYP3A4.

MATERIALS AND METHODS

Twenty-four piglets were divided into three groups: group 1 were controls (n = 11); group 2, ileal resection of 2/3 proximal small intestine (n = 5); and group 3, total small intestinal resection followed by 1/3 allotransplantation of ileum (n = 8). Tacrolimus was orally administered from postoperative days 3 to 7. On day 7, blood samplings were performed for the trough level and the calculation of area under the concentration time curve (AUC). Intestinal specimens from the jejunum, ileum, colon, and ileal graft were obtained on days 0 and 10 for immunohistochemistry of CYP3A4.

RESULTS

The trough and AUC values in group 2 were significantly higher than those in group 1. Furthermore those measurements in group 3 animals were higher than in group 2 (trough levels: 2.5 +/- 1.7, 11.2 +/- 2.1, 16.3 +/- 2.7 ng/mL and AUC values: 126 +/- 90, 319 +/- 155, 546 +/- 117 ng. h/mL). The expression levels of CYP3A4 were, jejunum > ileum > ileal graft > colon.

CONCLUSIONS

The intensity and extent of CYP3A4 staining diminished in the ileal graft showing an inverse correlation to the blood concentrations.

[Right ventricular myxoma with syncopal attach; report of a case]

Cardiac myxoma of right ventricle is rare. We report a 16-year-old girl who underwent an emergent surgical resection of right ventricular myxoma. She had syncopal attach in going to school and was referred to our hospital in emergency. There were no abnormal findings in brain computed tomography (CT) and electroencephalogram, but Levine IV/VI systolic ejection murmur was heard. Echocardiography and magnetic resonance imaging (MRI) revealed the presence of large mass in the right ventricle which was floating into the pulmonary artery. The tumor was removed completely through the both of main pulmonary artery and right atrium using cardiopulmonary bypass. The tumor was attached to the right ventricle free wall by a pedicle, which was 5 x 3 cm in size and was diagnosed as myxoma by histopathological examination.

Raised plasma oxidised LDL in acute cerebral infarction

BACKGROUND

The association between oxidised low density lipoprotein (OxLDL) and cerebral infarction is suspected but not established.

OBJECTIVES

To determine whether plasma OxLDL is a useful marker for monitoring oxidative stress in stroke patients.

METHODS

Plasma OxLDL concentrations were determined in 56 stroke patients with cerebral infarction (n = 45) or cerebral haemorrhage (n = 11), and in 19 age matched controls, using a novel sandwich enzyme linked immunosorbent assay.

RESULTS

Compared with the controls (0.130 (0.007) ng/ micro g LDL, mean (SEM)), OxLDL was significantly raised in patients with cerebral infarction (0.245 (0.022); p < 0.0001) but not in those with haemorrhage (0.179 (0.023)). Patients with cortical ischaemic infarcts (n = 22) had higher OxLDL levels than either the controls (p < 0.0001) or the patients with non-cortical ischaemic infarcts (n = 23) (p < 0.001). Increased OxLDL concentrations in patients with cortical infarcts persisted until the third day after stroke onset. The National Institutes of Health stroke scales in patients with cortical infarction were higher than in those with non-cortical infarction (p < 0.01).

CONCLUSIONS

There is a significant association between raised plasma OxLDL and acute cerebral infarction, especially cortical infarction. Plasma OxLDL may reflect oxidative stress in stroke patients.

Correlation between periodontal status and biting ability in Chinese adult population

This study investigated the relation between periodontal condition and biting ability in a Chinese population using the pressure-detecting sheet. A total of 142 subjects residing in Nanchang, Jiangxi province, China, participated in the study. The examination included probing pocket depth (PD), clinical attachment level (CAL), bleeding on probing and coronal caries teeth. Biting abilities per person, biting force, biting pressure and occlusal contact area were measured using the sheet. Number of teeth present showed positive correlation with biting force and occlusal contact area, but were negatively correlated with biting pressure. No significant correlation was observed between the mean PD, percentage of pocket > or = 4 mm, bleeding index and any of biting abilities. The mean CAL showed a significantly negative correlation with biting force and occlusal contact area. Multiple stepwise regression analysis selected the number of teeth present, sex and age as the significant factors affecting the biting ability. However, no periodontal indices were picked up as the significantly contributing factor. There appears to be little effect of periodontal condition on biting ability. Ageing was selected as a contributing factor to reduction in the Chinese adults, but not in the Japanese population.

Comparison of atopic cough with cough variant asthma: is atopic cough a precursor of asthma?

BACKGROUND

We have described a group of patients who present with isolated chronic bronchodilator resistant non-productive cough with an atopic constitution, eosinophilic tracheobronchitis, and airway cough receptor hypersensitivity without bronchial hyperresponsiveness, which we have termed "atopic cough". Although cough variant asthma (in which the cough responds to bronchodilators) is recognised as a precursor of typical asthma, it is not known whether atopic cough is also a precursor of asthma.

METHODS

Eighty two patients with atopic cough were retrospectively examined for onset of typical asthma and compared with 55 patients with cough variant asthma (20 untreated patients and 35 treated with long term inhaled beclomethasone dipropionate (BDP), 218-467 micro g/day). The median follow up period for patients with atopic cough and cough variant asthma was 4.8 (1-11.5) years and 3.7 (1-12.4) years, respectively.

RESULTS

Onset of typical asthma occurred in only one of the patients with atopic cough. In patients with cough variant asthma, typical asthma developed in two of 35 patients taking BDP and six of 20 untreated patients (difference 24.3%, 95% CI 2.8 to 45.8, p<0.02).

CONCLUSIONS

These findings suggest that cough variant asthma is a precursor of typical asthma but that atopic cough is not. Treatment with inhaled steroids may prevent the transformation of cough variant asthma into typical asthma.

LIGHT, a member of the TNF superfamily, induces morphological changes and delays proliferation in the human rhabdomyosarcoma cell line RD

LIGHT is a member of the tumor necrosis factor (TNF) superfamily, which binds two known receptors, lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/TR2. We investigated the effects of LIGHT on the human rhabdmyosarcoma cell line RD. LIGHT delayed cell proliferation and induced morphological changes of the cells. These effects were not shown by other TNF family ligands such as TNFalpha and LTalpha, which induced the transcriptional activity of nuclear factor-kappaB (NF-kappaB) and NF-kappaB-responsible chemokine productions in the same manner as did LIGHT. LTalpha1beta2, another TNF family ligand for LTbetaR, was shown to have similar activities in RD cells as LIGHT. Both LIGHT and LTalpha1beta2 induced the expression of muscle-specific genes such as smooth muscle (SM) alpha-actin, while TNFalpha and LTalpha did not. These findings indicate that LIGHT may be a novel inducer of RD cell differentiation associated with SM alpha-actin expression through the LTbetaR.

Subthalamo-pallido-striatal axis: a feedback system in the basal ganglia

Systemic administration of a dopamine D2 receptor blocker, haloperidol, but not vehicle, significantly increased the number of c-Fos-immunoreactive neurons in the globus pallidus (GP) in rats. Dual immunohistochemistry, a combination of c-Fos immunohistochemistry and retrograde tracing experiments with cholera toxin B (ChB), revealed that a subset of the c-Fos-immunoreactive GP neurons was pallidostriatal feedback neurons. Lesioning of the subthalamic nucleus (STN) by local injection of ibotenic acid inhibited the haloperidol-induced c-Fos expression in the GP neurons, suggesting that the activation of GP neurons is a result of increased excitatory drives from the STN. Therefore, the present findings are evidence of the existence of the subthalamo-pallido-striatal axis as a feedback system in the internal circuits of the basal ganglia.

Noradrenaline receptor-mediated potentiation of caffeine-induced Ca( 2+)-activated K(+) currents in bovine ciliary muscle cells

PURPOSE

Adrenoceptor-mediated modulation of a caffeine (CAF)-induced [Ca(2+)](i) elevation and resulting Ca(2+)-activated K(+) current (I(CAF)) in bovine ciliary muscle (CM) cells were investigated.

METHODS

The nystatin-perforated patch clamp technique for the measurement of membrane currents and a microscope based fura-2 fluorescence imaging of [Ca(2+)](i) were applied to CM cells freshly dissociated with collagenase and identified with smooth muscle-specific alpha-isoactin.

RESULTS

Under voltage-clamped conditions, noradrenaline (NA) potentiated I(CAF) in a NA concentration-dependent manner without producing current responses to NA when NA was applied alone. NA-induced potentiation of I(CAF) occurred within 20 sec after the application of NA, while the NA-potentiated I(CAF) gradually recovered to the control level within 30 min after removal of NA. Despite the little current response to NA applied alone, NA elicited a [Ca(2+)](i) elevation in a manner similar to that induced by CAF although the NA-induced [Ca(2+ )](i) elevation was smaller than the CAF-induced [Ca(2+ )](i) elevation. In contrast to the significant potentiation of I(CAF) with NA, NA produced little potentiation of the CAF-induced [Ca(2+)](i) elevation. The NA-induced potentiation of I( CAF) was antagonized by an alpha(1) adrenoceptor antagonist, prazosin. Neither clonidine nor isoproterenol had an effect on I(CAF), suggesting that alpha(2) and beta adrenoceptor are not involved in the response to NA.

CONCLUSIONS

These results suggest that NA potentiates I( CAF) via alpha(1) adrenoceptor activation and that the NA-induced potentiation occurs at Ca(2+)-activated K(+) channels but not CAF-induced Ca(2+) releasing sites.

Rat tripeptidyl peptidase I: molecular cloning, functional expression, tissue localization and enzymatic characterization

We purified tripeptidyl peptidase I (TPP I) to homogeneity from a rat kidney lysosomal fraction and determined its physicochemical properties, including its molecular weight, substrate specificity and partial amino acid sequence. The molecular weight of the enzyme was calculated to be 280,000 and 290,000 by non-denaturing PAGE and gel filtration, respectively, and to be 43 000 and 46 000 on SDS-PAGE in the absence and presence of beta-ME, respectively. These findings suggest that the enzyme is composed of six identical subunits. The Km, Vmax, kcat and kcat/Km values of TPP I at optimal pH (pH 4.0) were 680 microM, 3.7 micromol x mg(-1) x min(-1), 33.1 s(-1) and 4.87 x 10(4) s(-1) x M(-1) for Ala-Ala-Phe-MCA, respectively. TPP I was significantly inhibited by PCMBS and HgCl2, and moderately by DFP. These findings also suggest that TPP I is an exotype serine peptidase that is regulated by SH reagent. TPP I released the tripeptide Arg-Val-Tyr from angiotensin III more rapidly than from Ala-Ala-Phe-MCA, and also released Gly-Asn-Leu from neuromedin B with the same velocity as from Ala-Ala-Phe-MCA. Angiotensin III and neuromedin B have recently been found to be good natural substrates for lysosomal TPP I. Furthermore, we determined the rat liver cDNA structure and deduced the amino acid sequence. The cDNA, designated as lambdaRTI-1, is composed of 2485 bp and encodes 563 amino acids in the coding region. By Northern blot analysis, the order for TPP I mRNA expression was kidney > or = liver > heart > brain > lung > spleen >> skeletal muscle and testis. In parallel experiments, the TPP I antigen was detected in various rat tissues by immunohistochemical staining.

Molecular monitoring of bleomycin-induced pulmonary fibrosis by cDNA microarray-based gene expression profiling

Pulmonary fibrosis is a progressive disorder whose molecular pathology is poorly understood. Here we developed an in-house cDNA microarray ("lung chip") originating from a lung-normalized cDNA library. By using this lung chip, we analyzed global gene expression in a murine model of bleomycin-induced fibrosis and selected 82 genes that differed by more than twofold intensity in at least one pairwise comparison with controls. Cluster analysis of these selected genes showed that the expression of genes associated with inflammation reached maximum levels at 5 days after bleomycin administration, while genes involved in the development of fibrosis increased gradually up to 14 days after bleomycin treatment. These changes in gene expression signature were well correlated with observed histopathological changes. The results show that microarray analysis of animal disease models is a powerful approach to understanding the gene expression programs that underlie these disorders.

[Effectiveness of influenza vaccine in health-care workers]

We examined the effectiveness of trivalent influenza vaccine in reducing illness, absenteeism, and health care use among health-care workers (HCW) of Ishikawa Prefectural Central Hospital from December 1999 through March 2000. In recipients of vaccine (n = 132), the numbers of febrile illness, severe illness, febrile upper respiratory tract illness were significantly reduced compared with HCW without vaccination (n = 595). Use of prescription antibiotics and over-the-counter medications was also reduced. Influenza vaccine also reduced the reported days of work absence. These data support a policy of annual influenza vaccination of HCW.

Peptidases play an important role in cataractogenesis: an immunohistochemical study on lenses derived from Shumiya cataract rats

The role of proteolytic enzymes in Shumiya cataract rats in alterations to lens proteins during cataract formation was studied immunohistochemically using antibodies against exopeptidases, such as lysosomal dipeptidyl peptidase II (DPP II), cytosolic dipeptidyl peptidase III, and soluble and membrane-bound alanyl aminopeptidases, and against cytosolic endopeptidases such as mu- and m-calpains, and 20S proteasome. AlphaB-crystallin was detected as a proteolytic marker in the lenses. A constant immunoreactivity against all the antibodies employed was observed in the lens epithelium independent of the strain and age of the rats. A weak immunoreactivity against exo- and endopeptidases and an intense reactivity against alphaB-crystallin were observed in the lens fibres of control rats at all ages. The immunoreactivity of these peptidases in lens fibres increased with age in cataract rats, but that of alphaB-crystallin decreased. No reactivity against exo- and endopeptidases was seen in the perinuclear region of lenses of control rats at all ages or in Shumiya cataract rats at 8 and 10 weeks of age, but an intense reactivity against these peptidases was observed in the lens perinuclear region of lenses in cataract rats at 12 and 14 weeks of age. AlphaB-crystallin immunoreactivity was observed with ordered striations in the lens perinuclear region of all control rats whereas the striations in this area of cataract rat lens were disorganized. Membrane-bound alanyl aminopeptidase was detected feebly in the lens epithelium and fibres of both types of rat at all weeks of age. These findings indicate that exo- and endopeptidases, except for membrane-bound alanyl aminopeptidase, are expressed intensively and are age-dependent. Conversely, the amount of alphaB-crystallin decreased with age in lens fibres of cataract rats. Calpains (mu- and m-), 20S proteasome, dipeptidyl peptidases II and III and soluble alanyl aminopeptidase are thought to induce lens opacification kinetically during cataract formation in Shumiya cataract rats through the intracellular turnover of lens proteins.

Both the conserved and the unique gene structure of stomach-specific calpains reveal processes of calpain gene evolution

The proteins nCL-2 and nCL-2' are members of the Ca2+-dependent cysteine protease (calpain) superfamily, with stomach-specific expression. Like other typical calpains, nCL-2 has three distinct domains, a protease, a C2-like, and a 5EF-hand Ca2+-binding domain, as well as the N-terminal propeptide region. On the other hand, nCL-2' lacks the C2-like and 5EF-hand domains but is otherwise identical to nCL-2, except for the three C-terminal residues. To examine the stomach-specific and presumed alternative expression mechanisms of nCL-2 and nCL-2', we have cloned and characterized the mouse gene for nCL-2 and nCL-2'. The mouse nCL-2 gene contains at least 23 exons, spanning more than 50 kb, and possesses an exon specific for nCL-2' in the middle. Therefore, nCL-2 and nCL-2' are generated by alternative splicing of the same gene, Capn8. Capn8 shows the highly conserved gene organization of the other typical calpain large subunit genes, CAPN1, CAPN2, CAPN3, CAPN9, CAPN11, and Capn12, except for the unique exon between exon 9 and exon 10 of Capn8, which encodes the 3' half of the nCL-2' transcript. No such exon in the corresponding regions was found in CAPN1, CAPN2, CAPN3, CAPN9, or CAPN11. Gene and cDNA structures of a presumed human orthologue of mouse nCL-2, CAPN8, were determined, revealing that it overlaps human CAPN2, the gene for the m-calpain large subunit, in head-to-head orientation at 1q32-41. These features of Capn8 and CAPN8 illustrate a process of calpain gene evolution, i.e., the protease, C2-like, and 5EF-hand domains presumably functioned as independent genes, and the calpain superfamily has evolved by ordered fusions of these ancestral gene units, with subsequent amplifications.

Capsular bending ring to prevent posterior capsule opacification: 2 year follow-up

PURPOSE

To evaluate the preventive effect of a capsular bending ring on anterior and posterior capsule (PCO) opacification in a 2 year clinical study.

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

This study comprised 60 patients with senile cataract (35 women, 25 men) with a mean age of 69 years. An open poly(methyl methacrylate) capsular bending ring with a truncated edge profile designed to create a sharp bend in the equatorial capsule was implanted in 1 eye of patients with a hydroxyethyl methacrylate intraocular lens (IOL). The contralateral eye, which acted as a control, received an IOL but no ring. Patients were examined 6 months (n = 52), 1 year (n = 48), and 2 years (n = 42) postoperatively. Anterior capsule opacification was determined by slitlamp evaluation. Anterior capsule shrinkage (area within the capsulorhexis) and PCO were evaluated and scored using a computer software package for image analysis. Posterior capsule opacification was also measured by the rate of neodymium:YAG (Nd:YAG) capsulotomies.

RESULTS

Anterior capsule opacification and shrinkage were significantly less in eyes with the ring. The mean PCO score was 0.235 +/- 0.215 (SD), 0.287 +/- 0.200, and 0.398 +/- 0.248 with the ring and 0.530 +/- 0.190, 0.670 +/- 0.225, and 1.111 +/- 0.298 without the ring at 6 months, 1 year, and 2 years, respectively (P <.01 at each follow-up). An Nd:YAG laser capsulotomy was performed in 4 eyes with and 17 eyes without the ring after 2 years (P <.01).

CONCLUSIONS

The capsular bending ring significantly reduced anterior capsule fibrosis and shrinkage as well as PCO. The ring may be useful in patients who are at high risk of developing eye complications from capsule opacification that require Nd:YAG laser capsulotomy, in those expected to have vitreoretinal surgery and photocoagulation, and in cases of pediatric cataract.

Inhibition of lens epithelial cells by Fas-specific antibody activating Fas-Fas ligand system

PURPOSE

To detect cell specific apoptosis factors, Fas and Fas ligand, and the common intracellular apoptosis modulators, interleukin-1 beta converting enzyme (ICE)-like protease (caspase 1), Bcl-2, Bcl-xL and Bax in lens epithelial cells (LEC) of human cataracts. To study the effects of Fas-stimulating monoclonal antibody on inhibition of LEC proliferation.

METHODS

Reverse-transcriptase-polymerase chain reaction (RT-PCR) was used to detect Fas, Fas ligand, caspase 1, Bcl-2, Bcl-xL and Bax, after cDNA was synthesized from the total RNA isolated from human cataractous LEC obtained by capsulotomy during cataract surgery. Fas-stimulating monoclonal antibody was added at the concentrations of 10, 30, 100, 300 and 1000 ng/ml to the incubation medium of human cataractous LEC; and the specimens were incubated for 24 h at 37 degrees C with 5% CO(2) circulation and 100% humidity. The specimens were then stained with Hoechst 33342, and the number of apoptotic cells was counted.

RESULTS

Fas, caspase 1, Bcl-2, Bcl-xL and Bax mRNA were detected by RT-PCR. Fas ligand mRNA was not detected by RT-PCR. At each concentration, Fas-stimulating monoclonal antibody significantly inhibited LEC proliferation.

CONCLUSIONS

Human cataractous LEC expressed mRNA of Fas and various modulators of apoptosis pathways. Fas-stimulating monoclonal antibody may have the potential to prevent posterior capsule opacification after cataract surgery by inhibiting LEC proliferation.

Biological functions of extravasated serum IgG in rat brain

During blood-brain barrier opening serum IgG could be extravasated. The function of intraparenchymal IgG, however, is unknown. Its biological effects in the acute phase were currently investigated. From rat autoserum IgG was purified and injected into the cortex. Similarly, IgG-Fab fragment was prepared and administered likewise. As for the control group, only vehicle was injected. Animals were sacrificed on days 1, 2 and 4 after the infusion and were histologically evaluated. On days 1 and 2, the infusion of IgG caused significant intraparenchymal infiltration of neutrophils which expressed LFA-1-alpha. It also induced CR3 up-regulation in microglia and endothelial ICAM-1 expression. On day 4, these findings had disappeared. HE stained brain sections and the TUNEL method did not reveal significant nerve cell death in IgG injected animals during the experiment as compared to the controls. IgG-Fab did not cause significant changes either. Extravasated IgG has been viewed to have biochemical functions. Its Fc fragment seemed to cause microglial and endothelial activation, followed by leukocytic infiltration. This sequence itself was not neurotoxic. Therefore, it is suggested that extravasated IgG is one of the inducers that modulate cellular responses in the acute phase of brain damage.

[A case of relapsing polychondritis monitored by daily peak flow measurement]

A 55-year-old man was admitted to our hospital with dyspnea and stridor. At presentation, he also had a low grade fever, arthralgia and nasal obstruction. His chest roentgenogram showed diffuse tracheal narrowing, and chest CT revealed a thickened tracheal wall and fractured cricoid and thyroid cartilages. A diagnosis of relapsing polychondritis was made on the basis of his symptoms and in accordance with Damiani's criteria and CT findings. Daily peak flow (PEF) monitoring was carried out to assess the disease condition of the trachea. Methylprednisolone pulse therapy was started, and was followed by oral prednisolone, which improved his condition immediately, but reduction of oral prednisolone led to recurrence. The clinical course was clearly evaluated by PEF monitoring, but the change was undetectable on chest CT. Dapson, cyclophosphamide, and inhaled steroid were administered with oral prednisolone and the patient's condition has since been fair and stable. PEF monitoring may be useful for the early detection of recurrence in cases of relapsing polychondritis.

The cyclin-dependent kinase (CDK) inhibitor flavopiridol inhibits glycogen phosphorylase

Flavopiridol has been shown to induce cell cycle arrest and apoptosis in various tumor cells in vitro and in vivo. Using immobilized flavopiridol, we identified glycogen phosphorylases (GP) from liver and brain as flavopiridol binding proteins from HeLa cell extract. Purified rabbit muscle GP also bound to the flavopiridol affinity column. GP is the rate-limiting enzyme in intracellular glycogen breakdown. Flavopiridol significantly inhibited the AMP-activated GP-b form of the purified rabbit muscle isoenzyme (IC50 of 1 microM at 0.8 mM AMP), but was less inhibitory to the active phosphorylated form of GP, GP-a (IC50 of 2.5 microM). The AMP-bound GP-a form was poorly inhibited by flavopiridol (40% at 10 microM). Increasing concentrations of the allosteric effector AMP resulted in a linear decrease in the GP-inhibitory activity of flavopiridol suggesting interference between flavopiridol and AMP. In contrast the GP inhibitor caffeine had no effect on the relative GP inhibition by flavopiridol, suggesting an additive effect of caffeine. Flavopiridol also inhibited the phosphorylase kinase-catalyzed phosphorylation of GP-b by inhibiting the kinase in vitro. Flavopiridol thus is able to interfere with both activating modifications of GP-b, AMP activation and phosphorylation. In A549 NSCLC cells flavopiridol treatment caused glycogen accumulation despite of an increase in GP activity, suggesting direct GP inhibition in vivo rather than inhibition of GP activation by phosphorylase kinase. These results suggest that the cyclin-dependent kinase inhibitor flavopiridol interferes with glycogen degradation, which may be responsible for flavopiridol's cytotoxicity and explain its resistance in some cell lines.

Functional, metabolic, and histological changes of vascular tissues after warm ischemia

We examined functional, metabolic, and histological changes in the aortic tissue of rats after the period of warm ischemia ranging from 0 to 24 hours to determine the window of time in which grafts can be optimally viable for harvest. Sixty aortas from Brown Norway rats obtained after warm ischemia were used and changes in contraction, endothelial-dependent or -independent vasodilatation, cell viability, and histology were examined. Maximal contraction induced by norepinephrine and potassium chloride decreased time-dependently after exposure to warm ischemia. The warm ischemic period when 50% of the maximal contractile response of freshly isolated arteries was preserved, ranged from 6 to 8 hours. Maximal endothelium-dependent relaxation induced by acetylcholine decreased along with the time of warm ischemia. Endothelium-independent relaxation induced by sodium nitroprusside and forskolin was unaltered for up to 9 hours. Cell viability gradually decreased, and a significant negative correlation was found between warm ischemic period (T: hours) and cell viability (V: %) (V=101.9-2.35T; r(2)=0.96; p<0.0001). Cell viability was greater than 70% within 12 hours postmortem. Histologically, after 9-hour-warm ischemia irreversible changes were detected. Results suggest that the period of warm ischemia for up to 6 hours would be acceptable for preservation of tissue viability.