[Coronary artery bypass in octogenarians; how to reduce operative mortality and enhance long-term quality of life]

Octogenarians are at increased risk for perioperative morbidity and mortality after coronary artery bypass. This study is aimed to elucidate the suitable operative strategy and perioperative management. A retrospective analysis was conducted of 54 consecutive patients with 80-years of age or older, who underwent elective isolated coronary artery bypass between May 1999 and May 2008. Mean follow-up was 43.3 months and 96.3% complete. Operavive mortality was 3.7% and the incidence of stroke was 3.7%. The 7-year cardiac survival was 80.4% and the 7-year cardiac event free was 65.0%. The use of arterial graft to the right coronary artery was identified as independent predictor of late cardiac event. Neither total arterial revascularization nor bilateral internal thoracic artery grafting was a significant cardiac event factor. This retrospective study suggests a benefit of the less invasive strategy in terms of operative mortality and morbidity. Application of fast-track treatment in octogenarians appears to be an effective approach to reduce perioperative morbidity and enhance long-term quality of life.

Novel etodolac analog SDX-308 (CEP-18082) induces cytotoxicity in multiple myeloma cells associated with inhibition of beta-catenin/TCF pathway

We have reported previously that R-enantiomer of etodolac (R-etodolac), which is under investigation in phase 2 clinical trials in chronic lymphocytic leukemia, induces potent cytotoxicity at clinically relevant concentrations in multiple myeloma (MM) cells. In this study, we demonstrated that SDX-308 (CEP-18082), a novel analog of etodolac, has more potent cytotoxicity than R-etodolac against both MM cell lines and patient MM cells, including tumor cells resistant to conventional (dexamethasone, doxorubicine, melphalan) and novel (bortezomib) therapies. SDX-308-induced cytotoxicity is triggered by caspase-8/9/3 activation and poly (ADP-ribose) polymerase cleavage, followed by apoptosis. SDX-308 significantly inhibits beta-catenin/T-cell factor pathway by inhibiting nuclear translocation of beta-catenin, thereby downregulating transcription and expression of downstream target proteins including myc and survivin. Neither interleukin-6 nor insulin-like growth factor-1 protect against growth inhibition triggered by SDX-308. Importantly, growth of MM cells adherent to bone marrow (BM) stromal cells is also significantly inhibited by SDX-308. Our data therefore indicate that the novel etodolac analog SDX-308 can target MM cells in the BM milieu.

[Effects of dexmedetomidine hydrochloride on postoperative sedation in cardiovascular surgery]

BACKGROUND

Postoperative assessment of brain damage in cardiovascular surgery is often obscured by sedatives. Therefore, early postoperative detection of brain attack and its treatment are also hampered. A newly approved sedative, dexmedetomidine hydrochloride has weak analgesic effect and no respiratory depressive effect. These characteristics allow early assessment of brain damage after surgery. In this report, we compared 2 sedatives, propofol and dexmedetomidine hydrochloride, in cardiovascular settings.

SUBJECT AND METHODS

Both sedatives were initiated right after admission to the intensive care unit (ICU), followed by titrimetric method targeting for the sedation agitation scale (SAS) from 1 to 4. Thirty-five cases were included in dexmedetomidine hydrochloride group (DEX group) and 16 cases were included in propofol group (Prop group).

RESULTS

Preoperative and operative demographic data were the same between the 2 groups. Conversion rate to another sedatives, and incidence of vasopressor or hypotensor use were both in the same proportion in both groups. Intubated time was the same in both groups. Both systolic and diastolic blood pressures were kept lower in DEX group than Prop group until 8 hours after ICU admission. Other hemodynamic measurements, heart rate, pulmonary artery pressure and cardiac index showed no statistical difference. SAS and Ramsay score were better in DEX group early after ICU admission, and remained better until 10 hours later.

CONCLUSION

Dexmedetomidine hydrochloride has no major hemodynamic nor other side effects after cardiovascular surgery. Dexmedetomidine hydrochloride could be used as an effective agent for postoperative sedation and analgesia in cardiovascular settings.

[Aortic valve replacement in elderly patients with small aortic annulus; is the indexed effective orifice area important?]

We sought to determine whether the small indexed effective orifice area (EOAI) increased mortality and morbidity after aortic valve replacement (AVR) in patients over 75 years of age. From May 1999 to July 2005, 77 patients underwent isolated AVR for aortic stenosis. They were divided into 3 groups (S-EOAI : EOAI < or = 0.7 cm2/m2, M-EOAI : 0.7 cm2/m2 <EOAI < or = 0.85 cm2/ m2, L-EOAI : 0.85cm2/m2 <EOAI) for evaluation. We examined the body surface area (BSA), EOAI, and the left ventricular (LV) mass index (LVMI). We found that patients with S-EOAI had less symptomatic improvement (p <0.05, vs L-EOAI) and LV mass regression (p< 0.01, vs L-EOAI). But, their average New York Heart Association (NYHA) class was improved significantly (2.3 +/- 0.8 vs 1.8 +/- 0.7 : preoperative vs postoperative, p=0.001). Furthermore, severe patient-prosthesis mismatch (PPM) had no significant negative impacts on the freedom of valve-related complications (75.1% : S-EOAI group vs 92.0% : L-EOAI group) and the 5-year survival (84.9% : S-EOAI group vs 87.8% : L-EOAI group). In elderly patients, the average NYHA class was 1.9 +/- 0.6 postoperatively (p<0.0001 vs preoperative) and the LVMI showed significant regression (p<0.0001) despite an average EOAI of 0.73 +/- 0.13 cm2/m2. It is important to consider whether the benefits of avoiding PPM overcome the drawbacks of other complicated techniques. In this study, we found that moderate PPM (0.7 cm2/m2 < or = EOAI) is acceptable to elderly patients.

Invasive phenotype and apoptosis induction of Plesiomonas shigelloides P-1 strain to Caco-2 cells

AIMS

The mechanism of the host cell invasion of Plesiomonas shigelloides and its capability to induce apoptosis were investigated.

METHODS AND RESULTS

We performed a time course experiment on the bacterial adherence and invasion of the P. shigelloides P-1 strain into Caco-2 cells using an invasion assay and flow cytometry. The adherence of P. shigelloides to the Caco-2 cells was almost completed within 10 min after the infection. Thereafter, P. shigelloides starts internalization within the Caco-2 cells, which was completed within 60 min after the infection. Based on the invasion assay using nocodazole, cytochalasin D, and genistein, it became clear that the mechanism of the internalization depended on the signal transduction followed by the rearrangement of the cytoskeletal protein. Based on the DNA laddering and TUNEL methods, the cytotoxicity of the Caco-2 cells by the invasion of P. shigelloides occurred through the induction of apoptosis.

CONCLUSIONS

This work demonstrated that the mechanism of invasion of P. shigelloides into Caco-2 cells and the invasion of P. shigelloides induces apoptotic cell death.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work revealed the virulence factor, which may be important for understanding of the pathogenesis of P. shigelloides.

The subjective dimension of functioning and disability: what is it and what is it for?

The International Classification of Functioning, Disability and Health (ICF, WHO 2001) made a great advancement over ICIDH of 1980 in the understanding of the human functioning and disability. However, in both of them there is an important 'missing' element. That is the subjective dimension of functioning and disability. One of the authors (S. Ueda) published on this topic in 1981 both in Japanese and English. It had originated from his clinical experience in rehabilitation medicine. The understanding of the inner world of the client has proved a great asset in clinical practice. This paper explains its importance and provides a definition. It also proposes a tentative framework of a classification of subjective dimension of functioning and disability as the starting point for more intensive and extensive discussion on this important problem, and for its future inclusion into ICF.

Purification and identification of monoubiquitin-phosphoglycerate mutase B complex from human colorectal cancer tissues

Ubiquitin-conjugated proteins in human colorectal cancer tissues were analyzed by the immunoprecipitation with the antibody FK2 against conjugated ubiquitin followed with SDS-PAGE. In these immunoprecipitable proteins, a 38-kDa protein was abundant in the tumor regions but almost absent in the adjacent normal regions in 17/26 patients, thus we attempted to purify it. Using immunoaffinity chromatography with the antibody FK2 followed by gel filtration and SDS-PAGE, approximately 10 pmol of this protein was separated from 34 g of the pooled cancerous tissue and transferred onto a PVDF membrane. The 38-kDa protein was further digested with Achromobacter protease I, resulting in several peptide fragments. Amino acid sequences of these peptides showed complete sequence identity to those derived from either ubiquitin or phosphoglycerate mutase-B, suggesting that the 38-kDa protein is monoubiquitinated phosphoglycerate mutase-B, whose calculated mass is 37,369 Da. Western blot using an antibody against phosphoglycerate mutase-B revealed the presence of the 38-kDa protein in the anti-ubiquitin immunoprecipitates derived from the tumor regions, but not from normal counterparts. In addition, part of non-ubiquitinated phosphoglycerate mutase-B (29 kDa) was also found in the anti-ubiquitin immunoprecipitates, whose levels were higher in the tumor regions than in the adjacent normal regions. These results suggest that monoubiquitination of phosphoglycerate mutase-B as well as formation of a noncovalent complex containing ubiquitin and phosphoglycerate mutase-B increases in colorectal cancer and novel modification of phosphoglycerate mutase-B might have a pathophysiological role.

Clinical studies of bioabsorbable poly-L-lactide sternal coaptation pins

BACKGROUND

Median sternotomy has become the most commonly used incision in cardiac surgery. Since sternal dehiscence, however, is a major complication, we used bioabsorbable poly-L-lactide (P-L-LA) sternal coaptation pins for sternal closure to prevent it.

METHODS

From February 1998 to October 1999, 99 patients (64 men, 35 women; mean age, 63+/-1.2 years) underwent median sternotomy for cardiac surgery using sternal coaptation pins. Nineteen patients had diabetes mellitus and seven had renal failure. In closure, two sternal pins were inserted into the bone marrow of the sternum, one into the manubrium, the other into the body, and the sternum was sutured with five stainless steel wires.

RESULTS

Five patients died in the hospital. The causes of death were cardiac failure in two patients, respiratory problem in two and perforation of the stomach in one. The average length of hospitalization was 2 4.5+/-2.5 days. Sternal dehiscence occurred in one patient and mediastinitis in four. There was no bleeding from the bone marrow and no complication related to the use of the sternal pins.

CONCLUSIONS

P-L-LA sternal pins were easy to insert and may be effective in preventing dehiscence of the sternum.

Identification and characterization of the human serotonin-4 receptor gene promoter

The human serotonin-4 (5-HT(4)) receptor gene expression is highly regulated in various tissues. We isolated the human 5-HT(4) receptor gene containing the 5'-flanking region and characterized its promoter. By 5'-RACE (5'-rapid amplification of the cDNA ends) and inverse PCR, multiple transcription initiation sites were identified. The most 5' one (assigned to +1) was 5135 bp upstream to the translation start site. The 500-bp 5'-flanking region contained potential binding sites for transcription factor Sp-1, AP-2, AP-4, and GATA. However, this region lacked TATA- and CAAT-boxes. Transient transfection analyses in human choriocarcinoma T3M-3 (5-HT(4) receptor-positive) and HepG2 (5-HT(4) receptor-negative) cells revealed that the region (-210 to -105) is necessary for the basic and cell-type specific 5-HT(4) receptor gene expression. In addition, untranslated exon 1 contained negative (+112 to +182) as well as positive (+1 to +111) modulators, indicating that exon 1 plays a regulatory role in the 5-HT(4) receptor gene expression.

Isolation of ubiquitin-E2 (ubiquitin-conjugating enzyme) complexes from erythroleukaemia cells using immunoaffinity techniques

A variety of ubiquitin-associated (or conjugated) proteins, including substrates and enzymes for the ubiquitin system, are present in eukaryotic cells. In the present study we developed a simple method for their isolation, consisting of immunoaffinity chromatography using the monoclonal antibody FK2, which recognizes the conjugated ubiquitin molecule. Using this method followed by gel filtration, we isolated multi-ubiquitinated proteins with high molecular masses (>30 kDa) and also ubiquitinthioester-linked and mono-ubiquitinated forms of ubiquitin-conjugating (E2) enzymes, UbcH7 and UBE2N, together with mono-, di- and tri-ubiquitin molecules, from the cytoplasmic extract of heat-shock-treated K562 erythroleukaemia cells. We also demonstrated that the FK2 antibody was capable of precipitating a ubiquitin-UbcH7 thioester, but not free UbcH7, which enabled the measurement of the respective cellular levels separately. The immunoprecipitable ubiquitin-UbcH7 thioester was found only when the cells were treated with heat-shock. These results suggest the usefulness of the immunoaffinity techniques for identifying and analysing the cellular enzyme/protein-ubiquitin complexes.

Calpain inhibitor inhibits secretory granule maturation and secretion of GH

Clathrin- and AP-1-coated buds are present on immature secretory granules of endocrine cells that mature into clathrin-uncoated granules. The mechanism of clathrin and adaptor protein uncoating has remained obscure. Benzyloxycarbonyl-L-leucyl-L-leucinal (ZLLal), a calpain inhibitor, reduced growth hormone (GH) secretion with intracellular accumulation, in a GH-secreting rat pituitary tumor cell. Pulse and chase demonstrated that ZLLal retarded the turnover of clathrin (Clt.H) and adaptins. ZLLal-treatment co-immunoprecipitated the increased amounts of GH with Clt.H and adaptins compared to control cells, suggesting the intracellular accumulation of immature secretory granules. Clt.H and adaptins were limited-proteolyzed by m-calpain in vitro, indicating that calpain may be involved partly in the maturation of secretory granules in endocrine cells via the process of clathrin uncoating.

Comparison of standard coronary artery bypass grafting and minimary invasive direct coronary artery bypass grafting. Early and mid-term result

OBJECTIVES

We studied indications and problems involved in minimally invasive coronary artery bypass grafting (MIDCAB).

METHODS

We compared patients profiles, graft patency, stenosis severity, morbidity, mortality, long-term survival and freedom from cardiac accidents in 174 patients undergoing elective standard coronary artery bypass grafting (CABG) and 128 undergoing between January 1996 and March 1999.

RESULTS

No statistically difference was seen in gender, diabetes mellitus, renal failure, cerebrovascular accident, multi-vessel disease ratios, or left main trunk stenosis between 2 groups. Internal thoracic artery graft patency was 97% (114/118) and the rate of anastomotic stenosis (> 50%) was 9% (10/118) compared to 96% (213/221) in the MIDCAB group. The 3-year survival rate was 91% in the MIDCAB group and 92% in the CABG group and freedom from cardiac accidents, most involving pericutaneus transluminal coronary angioplasty retreatment, was 66% in the MIDCAB group and 88% in the CABG group.

CONCLUSION

Although patency and stenosis incidence did not differ between 2 groups, freedom from cardiac accidents was lower in the MIDCAB group.

Calpain inhibitor causes accumulation of ubiquitinated P-glycoprotein at the cell surface: possible role of calpain in P-glycoprotein turnover

P-glycoprotein (Pgp) is a plasma-membrane glycoprotein that confers multi-drug resistance (MDR) on cells and displays ATP-driven drug pumping. The possible contribution of calpain-mediated proteolytic pathways to the functional regulation of the Pgp molecule was evaluated using K562/DXR, MDR cells. N-Acetyl-L-leucyl-L-leucyl-norleucinal was effluxed by Pgp, but N-benzyloxycarbonyl-L-leucyl-L-leucinal (zLLal), an inhibitor of calpain, retarded the degradation of Pgp leading to accumulation of the molecule largely at the cell surface membrane. Treatment with brefeldin A did not obstruct the zLLal-induced Pgp accumulation. NH4Cl increased the cytoplasmic Pgp level, with a slight to significant decrease at the cell surface membrane. Ubiquitin-ELISA and western blot analysis confirmed that the Pgp molecule, which accumulated mainly at the cell surface, was ubiquitinated. However, lactacystin did not show any accumulation of Pgp in either the cytoplasm or the cell surface membrane, suggesting that the proteasome did not participate in the phenomenon. Additionally, the Pgp was limitedly proteolyzed by calpain into two 98 kDa and 69 kDa, fragments within one minute. Despite the increased accumulation of Pgp at the cell surface after treatment with calpain inhibitor, the cytoplasmic doxorubicin level of the cells treated with a calpain inhibitor was higher than that of non-treated cells and approached that of parental cells. These results indicated that calpain involved Pgp turnover and that calpain inhibition induced ubiquitinated Pgp-accumulation mainly at the cell surface membrane with a reduction in its own functions suggesting that the modulation of Pgp-turnover involves MDR-reversal by another approach.