ATP-independent fatty acyl-coenzyme A synthesis from phospholipid: coenzyme A-dependent transacylation activity toward lysophosphatidic acid catalyzed by acyl-coenzyme A:lysophosphatidic acid acyltransferase

CoA-dependent transacylation activity in microsomes is known to catalyze the transfer of fatty acids between phospholipids and lysophospholipids in the presence of CoA without the generation of free fatty acids. We previously found a novel acyl-CoA synthetic pathway, ATP-independent acyl-CoA synthesis from phospholipids. We proposed that: 1) the ATP-independent acyl-CoA synthesis is due to the reverse reaction of acyl-CoA:lysophospholipid acyltransferases and 2) the reverse and forward reactions of acyltransferases can combine to form a CoA-dependent transacylation system. To test these proposals, we examined whether or not recombinant mouse acyl-CoA:1-acyl-sn-glycero-3-phosphate (lysophosphatidic acid, LPA) acyltransferase (LPAAT) could catalyze ATP-independent acyl-CoA synthetic activity and CoA-dependent transacylation activity. ATP-independent acyl-CoA synthesis was indeed found in the membrane fraction from Escherichia coli cells expressing mouse LPAAT, whereas negligible activity was observed in mock-transfected cells. Phosphatidic acid (PA), but not free fatty acids, served as an acyl donor for the reaction, and LPA was formed from PA in a CoA-dependent manner during acyl-CoA synthesis. These results indicate that the ATP-independent acyl-CoA synthesis was due to the reverse reaction of LPAAT. In addition, bacterial membranes containing LPAAT catalyzed CoA-dependent acylation of LPA; PA but not free fatty acid served as an acyl donor. These results indicate that the CoA-dependent transacylation of LPA consists of 1) acyl-CoA synthesis from PA through the reverse action of LPAAT and 2) the transfer of the fatty acyl moiety of the newly formed acyl-CoA to LPA through the forward reaction of LPAAT.

Somatotopic arrangement and corticocortical inputs of the hindlimb region of the primary motor cortex in the macaque monkey

Using Japanese monkeys, we examined the somatotopic organization of the hindlimb region of the primary motor cortex (MI) with intracortical microstimulation. In the hindlimb region of the MI, areas representing distal movements (digits and ankle joints) were basically surrounded by those representing proximal movements (knee and hip joints). Thus, the hindlimb region of the MI has a nested or horseshoe-like somatotopic representation. We then examined the topographic organization of corticocortical projections to the hindlimb region of the MI by the retrograde double-labeling technique: one monkey received paired injections of Fast blue (FB) and Diamidino yellow (DY) into hindlimb or forelimb representation of the MI, respectively, while two monkeys received those of FB and DY into proximal or distal representation of the hindlimb region of the MI, respectively. The neurons projecting to the hindlimb region of the MI were located in cortical areas largely separate from those projecting to the forelimb region of the MI. On the other hand, we found a substantial overlap of corticocortical neurons projecting to the proximal and distal parts of the hindlimb region of the MI in the dorsal division of the premotor cortex and the cingulate motor areas.

Whole genome sequencing of meticillin-resistant Staphylococcus aureus

BACKGROUND

Staphylococcus aureus is one of the major causes of community-acquired and hospital-acquired infections. It produces numerous toxins including superantigens that cause unique disease entities such as toxic-shock syndrome and staphylococcal scarlet fever, and has acquired resistance to practically all antibiotics. Whole genome analysis is a necessary step towards future development of countermeasures against this organism.

METHODS

Whole genome sequences of two related S aureus strains (N315 and Mu50) were determined by shot-gun random sequencing. N315 is a meticillin-resistant S aureus (MRSA) strain isolated in 1982, and Mu50 is an MRSA strain with vancomycin resistance isolated in 1997. The open reading frames were identified by use of GAMBLER and GLIMMER programs, and annotation of each was done with a BLAST homology search, motif analysis, and protein localisation prediction.

FINDINGS

The Staphylococcus genome was composed of a complex mixture of genes, many of which seem to have been acquired by lateral gene transfer. Most of the antibiotic resistance genes were carried either by plasmids or by mobile genetic elements including a unique resistance island. Three classes of new pathogenicity islands were identified in the genome: a toxic-shock-syndrome toxin island family, exotoxin islands, and enterotoxin islands. In the latter two pathogenicity islands, clusters of exotoxin and enterotoxin genes were found closely linked with other gene clusters encoding putative pathogenic factors. The analysis also identified 70 candidates for new virulence factors.

INTERPRETATION

The remarkable ability of S aureus to acquire useful genes from various organisms was revealed through the observation of genome complexity and evidence of lateral gene transfer. Repeated duplication of genes encoding superantigens explains why S aureus is capable of infecting humans of diverse genetic backgrounds, eliciting severe immune reactions. Investigation of many newly identified gene products, including the 70 putative virulence factors, will greatly improve our understanding of the biology of staphylococci and the processes of infectious diseases caused by S aureus.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in synovial fluids of patients with temporomandibular joint osteoarthritis

AIMS

Imbalance between matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may be involved in the breakdown of articular cartilage matrix of the temporomandibular joint (TMJ). In this study, MMPs, TIMPs, and MMP-1/TIMP-1 complex levels were examined in TMJ synovial fluid samples aspirated from TMJ osteoarthritis (OA) patients (2 males, 8 females; mean age, 29.7 years) and asymptomatic control subjects (2 males, 8 females; mean age, 23.6 years) to determine the likelihood of increased proteolytic activity in the OA joints.

METHODS

The various types of MMPs and TIMPs were detected by Western blotting with monoclonal antibodies and gelatin zymography. The MMP-1/TIMP-1 complex level was measured by an enzyme-linked immunosorbent assay kit. All aspirates were first analyzed for total protein content and then individually diluted to make the total protein levels equivalent.

RESULTS

The mean MMP-1/TIMP-1 complex concentration in the synovial fluids of the OA patients was 3.92 +/- 1.39 ng/mL; this value was significantly lower (P < 0.05) than the value from control subjects (5.46 +/- 1.32 ng/mL). Matrix metalloproteinase-1 (52 kDa), MMP-3 (57 kDa), TIMP-1 (28 kDa), and TIMP-2 (26 kDa) were detected in all of the normal and the OA samples. However, MMP-1 (28 kDa), MMP-2 (72 kDa), MMP-3 (45 kDa), and MMP-9 (83 kDa) were detected in higher concentration in the OA samples.

CONCLUSION

These findings suggest a strong association between the OA-active joints and the presence of biologically active forms of known tissue degradation enzymes (MMP-1, MMP-3, and MMP-9).

Involvement of polyamines in B cell receptor-mediated apoptosis: spermine functions as a negative modulator

The B cell lymphoma WEHI231 has been used as a model for studying clonal deletion of B cells on the basis of its ability to undergo growth arrest and apoptosis by B cell antigen receptor (BCR) cross-linking. To comprehensively analyze the genes involved in BCR-mediated apoptosis, we applied the technique of serial analysis of gene expression (SAGE) to WEHI231. Comparison of expression patterns revealed that BCR cross-linking caused coordinate changes in the expression of genes involved in polyamine metabolism. Polyamines are ubiquitous compounds required for cell proliferation and homeostasis. The coordinate expression of the polyamine-related genes was confirmed by semiquantitative reverse transcriptase-polymerase chain reaction analysis. During apoptosis, the genes involved in polyamine biosynthesis were downregulated, whereas those involved in polyamine catabolism were upregulated, suggesting that intracellular polyamines play a role in BCR-mediated apoptosis. Levels of intracellular putrescine, spermidine, and spermine were reduced after BCR cross-linking. These effects were prevented by concurrent CD40 stimulation, which blocked BCR-mediated apoptosis. Furthermore, addition of spermine could repress the BCR-mediated apoptosis by attenuating the mitochondrial membrane potential (Deltapsim) loss and activation of caspase-7 induced by BCR signaling. These findings strongly suggest that polyamine regulation is involved in apoptosis during B cell clonal deletion.

Genomic organization, transcription start sites, and chromosomal location of the Drosophila cortactin gene

An actin filament binding protein cortactin was initially identified as a major phosphotyrosine-containing protein in v-Src-transformed chicken embryo fibroblast cells. The mouse, human, and Drosophila homologs were independently identified as a signaling molecule involved in a mitogenic response, as a product of a putative oncogene EMS1, and as a molecule interacting with a scaffolding protein ZO-1, respectively. In this report, we describe the cloning of the Drosophila cortactin gene, which consists of four exons and three introns, covering 3 kilobases in length. All exon-intron junctions are well matched with the GT/AG consensus sequence. S1 nuclease mapping revealed one major and several minor transcription start sites. The cytological location of the Drosophila cortactin gene is between chromosome segments 93B3 and 93B7.

Enhanced expression of matrix metalloproteinase-9 in abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by structural alterations of the aortic wall resulting from degradation of collagen and elastin. Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, show strong elastinolytic activity. We examined the levels of mRNA for MMP-2, MMP-9, membrane type (MT)-MMP-1, tissue inhibitor of metalloproteinase-1 (TIMP-1), and TIMP-2 in AAAs (n = 8), atherosclerotic occlusive diseases (AOD) (n = 8), and normal subjects (n = 8) using the reverse transcription-polymerase chain reaction (RT-PCR). We also analyzed the gelatinolytic activity of these metalloproteinases using gelatin zymography. The levels of MMP-2 and MMP-9 mRNA were increased in the AAA group compared with those in the AOD group and normal subjects. The levels for TIMP-1 and TIMP-2 mRNA in the AAA group were also higher than those in the AOD and normal groups. Only in the case of MT-MMP-1 was the difference between AAA and AOD not statistically significant. By gelatin zymography with the same samples used for RT-PCR, gelatinolytic activity of MMP-9 was elevated in all AAA tissues. The 62-kDa form of MMP-2 was elevated in both the AAA and AOD groups and did not differ significantly between them. Linear regression analysis demonstrated a significant positive correlation between mRNA levels of MMPs and those of TIMPs. These observations suggest that aneurysm formation in patients with atherosclerosis is related to the degree of MMP-9 expression.

Randomized controlled evaluation of non-surgical treatments for temporomandibular joint anterior disk displacement without reduction

The common methods for treating anterior disk displacement without reduction (ADDwor) are not based on randomized controlled clinical trials. Our study evaluated non-surgical treatments in 69 MRI-confirmed ADDwor subjects (m/f = 6/63). Subjects were randomly assigned to a control group and one of two treatment groups. Outcomes included maximum mouth opening, visual analogue scale of pain, and daily activity limitation. Calibrated examiners collected data at the initial interview and at 0, 2, 4, and 8 weeks of treatment. At the eight-week point, within-group improvements were present for all variables, for all groups. Between-group differences were not highly evident, with only mean daily activity limitation for the self-care/NSAID group being significantly lower than that of the occlusal appliance/jaw mobilization + self-care/NSAID group at the two- and four-week time-points. These results suggest that ADDwor subjects will improve with only minimal treatment intervention, and no significant difference was evident for the treatments tested and the control condition.

ORP150 protects against hypoxia/ischemia-induced neuronal death

Oxygen-regulated protein 150 kD (ORP150) is a novel endoplasmic-reticulum-associated chaperone induced by hypoxia/ischemia. Although ORP150 was sparingly upregulated in neurons from human brain undergoing ischemic stress, there was robust induction in astrocytes. Cultured neurons overexpressing ORP150 were resistant to hypoxemic stress, whereas astrocytes with inhibited ORP150 expression were more vulnerable. Mice with targeted neuronal overexpression of ORP150 had smaller strokes compared with controls. Neurons with increased ORP150 demonstrated suppressed caspase-3-like activity and enhanced brain-derived neurotrophic factor (BDNF) under hypoxia signaling. These data indicate that ORP150 is an integral participant in ischemic cytoprotective pathways.

Efficient photocleavage of DNA by cationic porphyrin-acridine hybrids with the effective length of diamino alkyl linkage

Positively charged porphyrins bearing an acridine with various lengths of diamino alkyl linkage, 5-[4-[(6-chloro-2-methoxy-9-acridyl)aminoalkylaminocarbonyl]phenyl]-10,15,20-tris(4-N-methylpyridiniumyl)porphine triiodide, alkyl=ethyl, butyl, hexyl, or octyl, were synthesized. They exhibited more enhanced photocleavage activity of pUC18 plasmid DNA than TMPyP, meso-tetrakis(4-N-methylpyridiniumyl)porphine, which is well known to bind to DNA tightly and to cleave DNA effectively; the hybrid linked with the hexamethylene chain showed particularly high activity. An equilibrium dialysis experiment demonstrated that the binding ability of the hybrids to calf thymus (CT) DNA correlated quantitatively with the photocleavage activity. The lack of the substantial red-shift of the Soret maxima of the hybrids through the titration with CTDNA denied the intercalative binding of the porphyrin part. In their circular dichroism (CD) spectral change on binding to CTDNA, two negative peaks appeared at 275 nm and at 285-290 nm in the UV range. The latter negative peak was observed for hybrids, but not for TMPyP, and thus we assigned it to induced CD (ICD) derived from intercalation of acridine chromophore. In the visible range, the hybrids showed only a positive peak around their Soret maxima, and this feature suggested the porphyrin moiety lay in the DNA groove. In addition, the length of the linker markedly influenced the ellipticity of their visible ICD, suggesting that the proximity of the porphyrin moiety to DNA was greatly affected by the linker.

A high low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio as a potential risk factor for corticosteroid-induced osteonecrosis in rabbits

OBJECTIVE

This study was designed to determine the potential risk factors for corticosteroid-induced osteonecrosis (ON) based on lipid metabolism, using a rabbit ON model.

METHODS

Blood samples were obtained from 38 rabbits, which then received a single intramuscular injection of 20 mg/kg methylprednisolone acetate. Four weeks after the injection, the femora and humeri were examined histopathologically for the presence of ON, and the sizes of the bone marrow fat cells were also measured.

RESULTS

Rabbits with and without ON differed significantly in the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LDL/HDL cholesterol ratio), which is considered to be a serological marker of lipid transport (P=0.026). The marrow fat cells were significantly larger in the rabbits with ON than in those without ON (P<0.0001).

CONCLUSION

A higher LDL/HDL cholesterol ratio was significantly associated with the development of ON, and such an elevated ratio may partly contribute to the increased size of marrow fat cells.

Axon trajectories in local circuits of the primary motor cortex in the macaque monkey (Macaca fuscata)

The intrinsic trajectories and terminal arbors of two axons and one horizontal axon collateral within the primary motor cortex (M1) were studied in the macaque monkey using injections of biotinylated dextran amine (BDA) into the putative primary forelimb motor cortex, and two-dimensional (2-D) reconstruction of the individually labeled axons and collateral. (1) A long collateral of the main axon from a large pyramidal cell in layer Vb of the putative forelimb area on the anterior bank of the central sulcus coursed horizontally anteriorly for 3 mm and formed a terminal arbor in layer III of M1. (2) The main axon of a pyramidal cell in layer IIIa+b of the putative forelimb area on the precentral gyrus descended into the white matter and then entered the anterior bank of the central sulcus to form a terminal arbor in layers III and V. (3) The main axon of a pyramidal cell in layer IIIc of the putative forelimb area on the precentral gyrus descended and bifurcated in the white matter. One branch entered the anterior bank of the central sulcus to form a terminal field in layer VI. These results indicate that some local axons and horizontal axon collaterals arising from M1 reach their single targets within M1 to form single terminal fields.

IL-2 independent transformation of a unique human T cell line, TY8-3, and its subclones by HTLV-I and -II

Human T cell leukemia virus type I (HTLV-I) is etiologically associated with adult T cell leukemia (ATL) and chronic neurological disease, tropical spastic paraparesis (TSP). In our study, a unique IL-2 dependent human T cell line, designated TY8-3, was established from a thymoma obtained from a myasthenia gravis patient. The cells were heterogeneous and mainly consisted of those with CD4 , CD8 as well as activation markers and adhesion molecules including IL-2Ralpha,beta,gamma, CD45RO, Tf-R, HLA-DR, LFA-1alpha,beta, LFA-3, ICAM-1 and OX40 but without CD3 surface markers. Furthermore, these cells underwent an efficient and reproducible IL-2 independent transformation upon cocultivation with HTLV-I/II producing cell lines. Interestingly, although the infected cells became IL-2 independent, the growth rate of infected cells was significantly lower than those of parental TY8-3 cells. Clonal HTLV-I proviral DNA and viral particles were detected in the cells. Down-regulation of the lck and fyn genes and activation of the lyn gene was demonstrated in the IL-2 independent HTLV-positive TY8-3 cells. Subclones of TY8-3 cells were again able to be efficiently transformed and became IL-2 independent several months after coculture. Our results thus exhibit that TY8-3 cells and its subclones provide us with a very unique model whereby IL-2 independent transformation events of human T cells by HTLV-I/II in vitro can be studied at a clonal level.

Rehabilitation of biting abilities in patients with different types of dental prostheses

This study investigated the masticatory rehabilitation of subjects wearing different types of prostheses. Biting abilities per person (biting force, biting pressure and occlusal contact area) were assessed with a pressure detecting sheet (Prescale(R)). Five hundred and ninety volunteers were divided into four groups according to the type of posterior dentition: complete denture, removable partial denture, fixed partial denture, and full natural dentition groups. The biting forces of the fixed partial, removable partial and complete denture wearers were 80, 35 and 11% respectively, when expressed as a percentage of the subjects with a natural dentition. The complete denture wearers showed the highest biting pressure among the four groups, followed by the removable partial denture wearers. In a clinical intra-individual study, the biting abilities of 85 subjects, without (before insertion of) and with (after insertion of) renewed prostheses, were compared. No significant differences were found between biting before and immediately after insertion of the prostheses. However, the biting force and occlusal contact area increased 2 months after insertion of the prostheses. This study confirmed past clinical studies indicating an impaired masticatory function of denture wearers. The functional adaptation to new prostheses had improved at evaluation 2 months after insertion.

Biomechanical calculation of human TM joint loading with jaw opening

A three-dimensional, static mathematical calculation of the stomatognathic system was done to predict total temporomandibular joint (TMJ) loading at different levels of jaw opening. The model assumed that muscle forces acting on the mandible could be simulated by a combination of contractile components (CCs) and elastic components (ECs) and that static equilibrium existed within the body of the mandible. The model also imposed the constraint that any generated joint reaction force would act on the centre of the condyle. The results of the model demonstrated that under all conditions of opening and for all values of the elastic modulus selected, the forces between the TMJ condyle and the articular eminence were compressive in nature. The compressive force magnitude increased from 2.7 to 27.6 N incrementally as the jaw opened from 10 to 40 mm. Overall data in this study indicated that the TMJ tissues undergo low levels of compression at open positions up to 40 mm. Finally, the condition of trismus (increased jaw closing activation with opening) was simulated, the joint reaction force at 20 mm opening increased from 7.7 to 64.9 N with only a 20% activation of the closers.

Characterization of Solt, a novel SoxLZ/Sox6 binding protein expressed in adult mouse testis

SoxLZ/Sox6, a member of the Sox protein family, contains a leucine zipper motif in addition to an HMG box, which is its DNA binding domain. Here we have identified a novel SoxLZ/Sox6 binding protein, termed Solt, which we obtained independently using both a far-Western blot and a yeast two-hybrid screen. Like SoxLZ/Sox6 mRNA, Solt mRNA was exclusively expressed in the testis in mouse. Solt contains an unusual leucine zipper, which bound to the leucine zipper region of SoxLZ/Sox6 in vitro. In transient transfection assays in CHO cells with SoxLZ/Sox6 containing the transactivational region of herpes simplex virus VP16, expression of a reporter gene that carries a cis binding region for Sox proteins was significantly enhanced by the co-expression of Solt and Ca(2+)/calmodulin-dependent protein kinase IV.

[Diagnosis of breast cancer extent using dynamic multidetector-row CT: correlation between MPR imaging and pathological cross-sections]

PURPOSE

To evaluate the clinical usefulness of dynamic multidetector-row CT (dynamic MD-CT) for the detection of intraductal extension of breast cancer.

MATERIALS AND METHODS

Dynamic MD-CT was performed in 31 patients with breast masses (26 invasive ductal carcinomas, 4 non-invasive ductal carcinomas and one benign lesion). We grouped the cases into four categories according to the degree of intraductal extension of the main tumor: IDS1: intraductal component less than 1 cm, IDS2: intraductal component 1 cm to 2 cm, IDS3: intraductal component 2 cm to 3 cm, IDS4: intraductal component more than 3 cm. To achieve complete CT-pathologic correlation, we retrospectively reconstructed MPR in the same plane as the histological cross-section.

RESULTS

Thirty breast carcinomas (100%) showed strong enhancement in both the first and second phases of contrast enhanced dynamic MD-CT. The sensitivity and specificity of dynamic MD-CT for the detection of the intraductal component were 80.0% (12/15) and 100% (15/15). The accuracy of detection for the four tumor categories was 100% (15/15) for IDS1, 25% (1/4) for IDS2, 42.9% (3/7) for IDS3, and 100% (4/4) for IDS4.

CONCLUSION

Dynamic MD-CT of the breast was found to be effective for the detection of intraductal extension of breast carcinoma and thought to be useful in the preoperative assessment of indications of breast-conserving surgery.

[Perioperative management of endovascular stent graft placement for abdominal aortic aneurysm]

We retrospectively examined the changes in hemodynamics, oxygen index and renal function along with the complications in 25 patients who had undergone endovascular stent graft placement (ESG) surgery for abdominal aortic aneurysm. During stent graft placement, mean arterial pressure decreased to 58 +/- 8 mmHg by increasing the dose of anesthetics and/or using vasodilators. Except for this intended hypotensive period, mean arterial pressure and heart rate were relatively stable and adequately maintained during surgical manipulation. Oxygenation index was well maintained. A patient with a high preoperative creatinine level underwent prophylactic hemodialysis postoperatively. In other patients except one who died in early postoperative period, both BUN and creatinine levels were kept within normal ranges. Four patients died postoperatively and the causes of the death in two patients are related to the surgical procedure; one with multiple emboli possibly due to released atheloma from the aortic wall during procedure, the other with sepsis due to infected stent graft. Although ESG is a well tolerated procedure, embolism is the most serious complication. Careful preoperative evaluation of the ascending arch and descending aortic wall and monitoring with transcranial doppler are necessary.

Expression of GAP-43 and SCG10 mRNAs in lateral geniculate nucleus of normal and monocularly deprived macaque monkeys

We performed nonradioactive in situ hybridization histochemistry (ISH) in the lateral geniculate nucleus (LGN) of the macaque monkey to investigate the distribution of mRNA for two growth-associated proteins, GAP-43 and SCG10. GAP-43 and SCG10 mRNAs were coexpressed in most neurons of both magnocellular layers (layers I and II) and parvocellular layers (layers III-VI). Double-labeling using nonradioactive ISH and immunofluorescence revealed that both GAP-43 and SCG10 mRNAs were coexpressed with the alpha-subunit of type II calcium/calmodulin-dependent protein kinase, indicating that both mRNAs are expressed also in koniocellular neurons in the LGN. We also showed that GABA-immunoreactive neurons in the LGN did not contain GAP-43 and SCG10 mRNAs, indicating that neither GAP-43 nor SCG10 mRNAs were expressed in inhibitory interneurons in the LGN. GABA-immunoreactive neurons in the perigeniculate nucleus, however, contained both GAP-43 and SCG10 mRNAs, indicating that both mRNAs were expressed in inhibitory neurons in the perigeniculate nucleus, which project to relay neurons in the LGN. Furthermore, to determine whether the expression of GAP-43 and SCG10 mRNAs is regulated by visual input, we performed nonradioactive ISH in the LGN and the primary visual area of monkeys deprived of monocular visual input by intraocular injections of tetrodotoxin. Both mRNAs were downregulated in the LGN after monocular deprivation for 5 d or longer. From these results, we conclude that both GAP-43 and SCG10 mRNAs are expressed in the excitatory relay neurons of the monkey LGN in an activity-dependent manner.

MAPK upstream kinase (MUK)-binding inhibitory protein, a negative regulator of MUK/dual leucine zipper-bearing kinase/leucine zipper protein kinase

Mitogen-activated protein kinase upstream kinase/dual leucine zipper-bearing kinase/leucine-zipper protein kinase (MUK/DLK/ZPK) is a MAPKKK class protein kinase that induces JNK/SAPK activation. We report here a protein named MBIP that binds to MUK/DLK/ZPK. MUK-binding inhibitory protein (MBIP) contains two tandemly orientated leucine-zipper-like motifs with a cluster of basic amino acids located between the two motifs. MBIP interacts with one of the two leucine-zipper-like motifs of MUK/DLK/ZPK and inhibits the activity of MUK/DLK/ZPK to induce JNK/SAPK activation. Notably, no similar effect was observed with another JNK/SAPK-inducing MAPKKK, COT/Tpl-2, showing the specificity of MBIP action. Furthermore, the overexpression of MBIP partially inhibits the activation of JNK by 0.3 m sorbitol in 293T cells. Taken together, these observations indicate that MBIP can function as a regulator of MUK/DLK/ZPK, a finding that may provide a clue to understanding the molecular mechanism of JNK/SAPK activation by hyperosmotic stress.

Ultrastructural and functional studies of cryopreserved rat lungs for transplantation using a new hyperosmolal solution

One of the most promising approaches for extending the period of tissue or organ preservation is to induce a state of cryopreservation. In this report, to achieve successful lung cryopreservation, we created a new hyperosmolal solution (HOS) containing 10% glycerol and 5% dimethyl sulfoxide (Me2SO). We compared the efficacy of HOS with that of Euro-Collins solution (ECS) in rat lung cryopreservation from an ultrastructural and functional point of view. Using ECS, widespread damage to the air-blood barrier was observed even in the lungs cryopreserved at -10 degrees C. At -196 degrees C, the capillary lumen was obstructed with a mesh-like formation derived from deteriorated endothelial cells. In contrast, using HOS, the cryopreserved lungs at -10 degrees C were characterized by well preserved endothelial cells and basal laminae, despite the existence of focal cytoplasmic swelling of epithelial cells. The endothelial cells and basal laminae were successfully preserved up to -196 degrees C. Considering the survival rates at day 7 after cryopreserved lung transplantation, the grafted left lungs functioned normally only when perfused by and preserved in HOS at -10 degrees C. These findings demonstrate that HOS was effective not only for endothelial cells and basal laminae up to -196 degrees C, but also lung cryopreservation at least up to -10 degrees C.

The influence of blood contamination on bond strengths between dentin and an adhesive resin cement

The objective of this study was to determine in which step of adherent surface treatments blood contamination affects the bond strength between an adhesive resin and dentin. The coronal part of bovine incisors was polished flat to expose the dentin. The specimens were randomly divided into three groups and specific surface treatments were applied to each group: (1) a self-etching primer application (SP group); (2) 38% phosphoric acid etching followed by primer (non-HC group); (3) acid etching followed by 10% sodium hypochlorite solution application and primer (HC group). The dentin surface was contaminated by human blood before or after either step of the surface treatments. The contaminated surfaces were washed with water after 30-second exposure and air-dried. A stainless-steel rod was adhered on the dentin surface with Panavia 21 after completing the surface treatment(s), and the tensile bond strength was measured. Fifteen subgroups including control groups were tested. If blood contamination occurred before collagen fibers were exposed by either phosphoric acid etching or self-etching primer application, the contamination presented almost no influence on bond strength. Blood contamination of the dentin surface where collagen fibers had been exposed decreased the bond strength. However, when the contaminated collagen fibers were dissolved or when the contamination occurred after the exposed collagen fibers were dissolved, the bond strength was maintained. The bond strength was markedly decreased when the contamination occurred after the primer application (Scheffé's Comparison, SP group: p = 0.0003, non-HC group: p < 0.0001), but was restored by reapplication of the self-etching primer. This study revealed that the effects of blood contamination on the bond strength of adhesive resin to dentin vary greatly depending on the adherent surface conditions.

Atypical aortic coarctation with resistant hypertension treated with axilloiliac artery bypass

A 68-year-old woman was found to have atypical coarctation of the aorta, accompanied by systolic hypertension of the upper extremities despite administration of five types of antihypertensive drugs. Since the systolic hypertension was resistant to the conventional antihypertensive therapy, axilloiliac artery bypass grafting with a subcutaneous tunnel was performed to alleviate the pressure gradient. Systolic blood pressure was successfully reduced and hypertension was controlled after surgery.