Comparison of surgical treatments for distal ulna fracture when combined with anterior locking plate fixation of distal radius in the over 70 age group

We conducted a retrospective multicentre study to compare the clinical and radiographic outcomes, and complications of three surgical treatments of distal ulna fracture (DUF) when combined with anterior locking plate fixation for distal radial fracture (DRF) in patients over 70 years of age. We identified 1521 patients over 70 years of age who were diagnosed as having DRF and who underwent anterior locking plate fixation between 2015 and 2020, among which 122 cases of DUF were analysed. Three surgical treatment options for DUF were identified in this cohort: K-wire fixation (Group K), locking plate fixation (Group L) and Darrach procedure (Group D). The results of the analysis showed the total immobilization period in Group D to be the shortest among the three treatments. Functional outcomes were superior, and the rate of complications were smaller in Group D than in Group L. In addition, rotational range of motion was larger in Group D and Group L compared with Group K. In patients who are 70 years of age or older with combined unstable DRF and highly comminuted or displaced DUF, the Darrach procedure for DUF seems to be the most useful and reasonable treatment option once the fracture of the distal radius has been rigidly fixed.Level of evidence: IV.

Longer time of implantation using the buried pin technique for intramedullary nailing would decrease refracture in the diaphyseal forearm fracture in children-retrospective multicenter (TRON) study

BACKGROUND

Intramedullary nailing using Kirschner wires in pediatric diaphyseal forearm fractures is often performed as a less invasive treatment than plate fixation, but it remains controversial whether the tips of Kirschner wires are buried or exposed. The purpose of this study was to investigate the relationship between whether the tips are buried or exposed and complications, especially of refracture.

METHODS

Data of 405 patients under 16 years who underwent surgical treatment for diaphyseal forearm fractures in our 11 hospitals between 2010 and 2020 were collected. Finally, 143 patients who underwent intramedullary nailing with at least 6-month follow-up were analyzed. We investigated difference in complication rates depending on whether the Kirschner wire tips were buried (Group B: n = 79) or exposed (Group E: n = 64). Regarding refractures, we also examined time of onset and status of bone union before the refracture occurred.

RESULTS

The duration before implant removal in Group B was more than 4 times longer than that in Group E (mean 187.9 vs. 41.4 days, p<0.001), although there was no significant difference in the progression of bone union between the two groups. Regarding postoperative complications, Group B had a significantly lower rate of refractures than Group E (7.9% vs. 32.8%, p<0.001), although the rate of irritation pain was significantly higher (15.2% vs. 1.6%, p = 0.006). The infection rate was also lower in Group B than Group E, but not significantly so (3.8% vs. 10.9%, p = 0.112). Refractures between 3 and 9 months after surgery accounted for 66.7% of all refractures, and those within 3 months accounted for 14.5% of all fractures. There was no significant difference in the status of bone union before the refracture occurred between patients with and without refracture.

CONCLUSIONS

The present study showed that longer time of implantation using the buried pin technique for intramedullary nailing reduces refracture of pediatric diaphyseal forearm fractures. Because of the risk of refracture during remodeling, we recommend the implantation of intramedullary nailing for 6-9 months and the instruction for the patients and the parents to pay more attention to refracture at least within 9 months postoperatively.

LEVEL OF EVIDENCE

Level Ⅲ, Multicenter retrospective study.

Patients with benign hand tumors are indicated for surgery according to patient-rated outcome measures

INTRODUCTION

This study assessed the treatment outcomes of upper extremity benign tumors using the patient-rated outcome measures of Hand20 questionnaire.

METHODS

In total, 304 patients who underwent surgery for benign bone and soft tissue tumors of the upper limb were included. Tumors were classified into three size groups: <1 cm, 1-3 cm, and >3 cm. Tumors were divided with respect to location: digit, hand, wrist, forearm, elbow, upper arm, or axilla. We prospectively assessed responses to the Hand20 questionnaire that was administered both before and after surgery.

RESULTS

The mean Hand20 and pain scores significantly improved after surgery in patients with ganglion cysts, giant cell tumors of the tendon sheath, enchondromas, or pyogenic granulomas. For patients with hemangiomas, schwannomas, or glomus tumors, although the mean pain scores improved significantly following surgery, there were no significant changes in the mean Hand20 scores. However, the statistical power for this analysis was low. The mean Hand20 and pain scores improved significantly, regardless of the size grouping. The mean Hand20 scores significantly improved after surgery in patients with finger, thumb, hand, or wrist tumors. Except for elbow to axillary tumors, the mean pain scores significantly improved in all patients.

CONCLUSION

The results of Hand20 and pain scores suggest that most patients with benign hand tumors are indicated for surgery, but the degree of improvement differs according to tumor pathology and location but not size.

Clinical effects of internal fixation for ulnar styloid fractures associated with distal radius fractures: A matched case-control study

BACKGROUND

Ulnar styloid fractures are often associated with distal radius fractures. However, controversy exists regarding whether to treat ulnar styloid fractures. This study aimed to evaluate clinical effects of internal fixation for ulnar styloid fractures after distal radius fractures were treated with the volar locking plate system.

METHODS

We used prospectively collected data of distal radius fractures. 111 patients were enrolled in this study. A matched case-control study design was used. We selected patients who underwent fixation for ulnar styloid fractures (case group). Three control patients for each patient of the case group were matched on the basis of age, sex, and fracture type of distal radius fractures from among patients who did not undergo fixation for ulnar styloid fractures (control group). The case group included 16 patients (7 men, 9 women; mean age: 52.6 years; classification of ulnar styloid fractures: center, 3; base, 11; and proximal, 2). The control group included 48 patients (15 men, 33 women; mean age: 61.1 years; classification of ulnar styloid fractures: center, 10; base, 31; and proximal, 7). For radiographic examination, the volar tilt angle, radial inclination angle, and ulnar variance length were measured, and the union of ulnar styloid fractures was judged. For clinical examination, the range of motions, grip strength, Hand20 score, and Numeric Rating Scale score were evaluated.

RESULTS

There was little correction loss for each radiological parameter of fracture reduction, and these parameters were not significantly different between the groups. The bone-healing rate of ulnar styloid fractures was significantly higher in the case group than in the control group, but the clinical results were not significantly different.

CONCLUSIONS

We revealed that there was no need to fix ulnar styloid fractures when distal radius fractures were treated via open reduction and internal fixation with a volar locking plate system.

Teletriage for patients with traumatic finger injury directing emergency medical transportation services to appropriate hospitals: a pilot project in Nagoya City, Japan

INTRODUCTION

Emergency medical technicians in Japan have experienced difficulties in identifying hospitals that will accept patients with severe finger injuries. We developed and managed a system named Interactive Teletriage using mobile phone photos to aid efficient patient transportation. The aim of this study was to investigate features related to the transportation of patients with severe finger injuries and to evaluate the feasibility of this system.

MATERIALS AND METHODS

We prospectively analysed data from the medical association of Aichi Prefecture and the Nagoya City Fire Department in Japan. We investigated features related to the transportation of 474 patients with severe finger injuries in Nagoya from 2010 to 2013: 100 in 2010, 134 in 2011, 125 in 2012, and 115 in 2013. We began using Teletriage in August 2011 and compared the periods before and after its implementation.

RESULTS

The time of injury showed two different peaks from 09:00 to 11:00h and at 13:00h. The number of patients injured during each weekday was generally the same, while cases on Saturdays and Sundays reflected 70% and 47% of the weekday average, respectively. Of the 474 patients, 395 (83%) were accepted to hospitals after 3 or fewer requests for admission: 160 of 202 (79.2%) before and 235 of 272 (86.4%) after Teletriage, constituting a significant increase (p=0.039). Furthermore, the number of patients who required 4 or more requests significantly decreased after implementation of Teletriage (p=0.039): 42 patients (20.8%) before and 37 (13.6%) after Teletriage. Our data showed that as the number of requests until final determination increased, the transportation period increased. Furthermore, the mean transportation period significantly decreased from 22.3min before to 18.1min after Teletriage (p=0.021). As the number of requests until final determination increased, the proportion of patients transported to Level I and II hospitals decreased; conversely, the proportion of patients transported to Level III, IV, and V hospitals increased.

CONCLUSIONS

Our results indicated that the implementation of Teletriage has the potential to ease the problem of emergency medical transportation for those with severe finger injuries.

[Orthopaedic neurological diseases in patient with diabetes]

Individuals with diabetes are at a greater risk for microvascular complications, such as retinopathy, neuropathy, and nephropathy, than are individuals without diabetes. Diabetic neuropathies are complex heterogeneous disorders that include both focal neuropathies and diffuse polyneuropathy. Entrapment neuropathy is an example of a focal neuropathy, while distal symmetric polyneuropathy is the most common type of diffuse polyneuropathy. Entrapment neuropathies are highly prevalent in the diabetic population, but they develop insidiously and progressively, making it difficult to determine their true prevalence. Entrapment neuropathies are suspected to be a more common complication of diabetes than is polyneuropathy. For example, carpal tunnel syndrome (CTS)-one of the most common entrapment neuropathies encountered in patients with diabetes-results from median nerve compression, and has been shown to occur three times more frequently in a diabetic population than in a normal healthy population. Entrapment neuropathies should be actively screened for in patients showing the signs and symptoms of neuropathy, because such patients may require surgical treatment.

Targeting anti-inflammatory treatment can ameliorate injury-induced neuropathic pain

Tumor necrosis factor-α plays important roles in immune system development, immune response regulation, and T-cell-mediated tissue injury. The present study assessed the net value of anti-tumor necrosis factor-α treatment in terms of functional recovery and inhibition of hypersensitivity after peripheral nerve crush injury. We created a right sciatic nerve crush injury model using a Sugita aneurysm clip. Animals were separated into 3 groups: the first group received only a skin incision; the second group received nerve crush injury and intraperitoneal vehicle injection; and the third group received nerve crush injury and intraperitoneal etanercept (6 mg/kg). Etanercept treatment improved recovery of motor nerve conduction velocity, muscle weight loss, and sciatic functional index. Plantar thermal and von Frey mechanical withdrawal thresholds recovered faster in the etanercept group than in the control group. On day 7 after crush injury, the numbers of ED-1-positive cells in crushed nerves of the control and etanercept groups were increased compared to that in the sham-treated group. After 21 days, ED-1-positive cells had nearly disappeared from the etanercept group. Etanercept reduced expression of interleukin-6 and monocyte chemotactic and activating factor-1 at the crushed sciatic nerve. These findings demonstrate the utility of etanercept, in terms of both enhancing functional recovery and suppressing hypersensitivity after nerve crush. Etanercept does not impede the onset or progression of Wallerian degeneration, but optimizes the involvement of macrophages and the secretion of inflammatory mediators.

Control of AIF-mediated cell death by antagonistic functions of CHIP ubiquitin E3 ligase and USP2 deubiquitinating enzyme

Apoptosis inducing factor (AIF) is a mitochondrial oxidoreductase that scavenges reactive oxygen species under normal conditions. Under certain stresses, such as exposure to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG), AIF is truncated and released from the mitochondria and translocated into the nucleus, where the truncated AIF (tAIF) induces caspase-independent cell death. However, it is unknown how cells decide to kill themselves or operate ways to survive when they encounter stresses that induce the release of tAIF. Here, we demonstrated that USP2 and CHIP contribute to the control of tAIF stability. USP2 deubiquitinated and stabilized tAIF, thus promoting AIF-mediated cell death. In contrast, CHIP ubiquitinated and destabilized tAIF, thus preventing the cell death. Consistently, CHIP-deficient cells showed an increased sensitivity to MNNG. On the other hand, knockdown of USP2 attenuated MNNG-induced cell death. Moreover, exposure to MNNG caused a dramatic decrease in CHIP level, but not that of USP2, concurrent with cell shrinkage and chromatin condensation. These findings indicate that CHIP and USP2 show antagonistic functions in the control of AIF-mediated cell death, and implicate the role of the enzymes as a switch for cells to live or die under stresses that cause tAIF release.

Reference profiling of the genomic response induced by an antimicrotubule agent, TZT-1027 (Soblidotin), in vitro

TZT-1027 is an antimicrotubule agent targeting beta-tubulin that is undergoing clinical development. The genomic response of cancer cells to TZT-1027 was profiled to evaluate its biochemical activity. A lung cancer cell line, PC-14, was exposed to antimicrotubule agents including dolastatins, Vinca alkaloids and taxanes at an equivalent toxicity level. Alterations in the TZT-1027-induced gene expression of approximately 600 genes were then examined using microarray technology and the resulting gene profiles were compared with those for cells exposed to the other antimicrotubule agents. A principle component analysis using the whole gene set demonstrated that TZT-1027 produced similar gene profiles to those produced by dolastatin 10, but that these gene profiles differed from those produced by other agents. The agents were classified according to their induced genomic response in a molecular structure-dependent manner. Genes whose expression profiles differed according to drug class included intermediate filaments, extracellular matrix protein and Rho regulatory genes that may be involved in cytoskeletal and angiogenesis processes that are regulated by microtubule dynamics. TZT-1027 produces a unique genomic response profile distinct from that of Vinca alkaloids and taxanes, suggesting that this agent has a different mechanism of action. The selected genes may act as pharmacodynamic biomarkers allowing the unique mode of action of TZT-1027 to be discriminated from those of other antimicrotubule agents.

Investigation of a Kubo-formula-based approach to estimate DNA conductance in an atomistic model

A novel approach to estimate DNA conductance based upon Kubo formula is presented and discussed. Using this approach, the effects of base pair mismatches, different conformational changes and base pair sequence on DNA electrical properties were investigated. The results were compared with the data from other methods. The new approach makes possible very fast estimation of conductance spectra for oligonucleotides with hundreds of base pairs and can easily be extended to treat arbitrary chemical modifications of DNA.

Gene expression profiling of exposure to TZT-1027, a novel microtubule-interfering agent, in non-small cell lung cancer PC-14 cells and astrocytes

Clinical use of TZT-1027, a microtubule-interfering agent that inhibits the polymerization of tubulin, is expected because of its potent effects on solid tumors. TZT-1027 is thought to act directly on cellular microtubules, and arrest cell mitosis, however, the molecular mechanisms of the microtubule damage by TZT-1027 have not been fully identified. To investigate the possible novel mechanisms of action of TZT-1027, we used the cDNA macroarray technique to examine its effect on the expression of hundreds of tightly transcriptionally controlled genes. We used two cell lines, one was human non-small cell lung carcinoma PC-14 cells as a model for cancer cells, and the other was human astrocytes as a model for normal neuronal cells, because the dose-limiting-factor of microtubule-interfering agents is mainly peripheral neurotoxicity. mRNAs prepared from the PC-14 and astrocyte cell lines treated with TZT-1027 were compared with 588 genes spotted onto the filter, and which gene groups TZT-1027 modulated between the two cell lines was investigated. TZT-1027 exposure modulated expression of a variety of genes including the genes encoding cell-cycle and growth regulators, receptors, angiogenesis and invasion regulators, rho family small GTPases and their regulators and growth factors and cytokines. However, the way of gene regulation by TZT-1027 exposure was different between PC-14 cells and astrocytes. Genes up-regulated in both PC-14 cells and astrocytes were those for RAR-epsilon, TNFR 1 and 2 and so on. Specifically altered genes in PC-14 cells, such as the genes coding for cytokeratin 8, XPG, fau and the genes regulated only in PC-14 cells may be involved in the antitumor activity of TZT-1027. On the other hand, growth factor receptor precursors was upregulated specifically in astrocytes by TZT-1027 and this gene regulation only in astrocytes may be candidates related with neurotoxicity.

BIA-MS-MS: biomolecular interaction analysis for functional proteomics

One of the experimental processes of functional proteomics is the analysis of protein interaction. Here, we review a new analytical platform, BIA-MS, for protein interaction analysis. BIA-MS is an integration of a surface plasmon resonance biosensor for real-time interaction analysis and mass spectrometry for the subsequent identification of interacting molecules.

Association of p53 gene mutations with sensitivity to TZT-1027 in patients with clinical lung and renal carcinoma

BACKGROUND

It has been revealed that chemotherapy using DNA-damaging agents and radiotherapy were influenced by the p53 status of tumors; however, p53 status did not influence chemotherapy using antimicrotubule agents. To elucidate whether a novel antimicrotubule agent, TZT-1027, is influenced by the p53 status of tumors, the authors investigated the sensitivities of specimens obtained from patients with nonsmall cell lung carcinoma (NSCLC) and renal cell carcinoma (RCC) to various anticancer agents, including TZT-1027, and the status of the p53 gene in those specimens.

METHODS

Twenty-nine NSCLC specimens and 22 RCC specimens were analyzed for their sensitivity to various anticancer agents and their p53 status. Sensitivities of the specimens to nine anticancer agents were determined by flow cytometric analysis. To determine p53 status, polymerase chain reaction amplification with primers for exons 5--9 was conducted, and the products were subjected to single-strand conformation polymorphism analysis.

RESULTS

In the NSCLC specimens, anticancer agents, including TZT-1027, showed strong antitumor activity against 50--75% of specimens with the wild type p53 gene. TZT-1027 showed strong antitumor activity against 40% of specimens with the mutant type p53 gene, whereas DNA-damaging agents showed such activity only in 16--28% of specimens. In RCC specimens, TZT-1027 showed potent antitumor activity in 29% of specimens with the wild type gene, and DNA-damaging agents showed such activity in 6--18% of specimens. TZT-1027 showed strong antitumor activity in 40% of specimens with the mutant type p53 gene, whereas DNA-damaging agents showed such activity only in 0--20% of specimens.

CONCLUSIONS

We found evidence to suggest that TZT-1027 was influenced less by the p53 status of specimens than DNA-damaging agents. Therefore, TZT-1027 is expected to show similar antitumor activity against tumors with a loss of p53 function as well as those with normal function of p53 in clinical fields.

Identification of the ligand-binding site of the BMP type IA receptor for BMP-4

Bone morphogenetic proteins (BMPs) belong to the transforming growth factor-beta (TGF-beta) superfamily of multifunctional cytokines. BMP induces its signal to regulate growth, differentiation, and apoptosis of various cells upon trimeric complex formation with two distinct type I and type II receptors on the cell surface: both are single-transmembrane serine/threonine kinase receptors. To identify the amino acid residues on BMP type I receptor responsible for its ligand binding, the structure-activity relationship of the extracellular ligand-binding domain of the BMP type IA receptor (sBMPR-IA) was investigated by alanine-scanning mutagenesis. The mutant receptors, as well as sBMPR-IA, were expressed as fusion proteins with thioredoxin in Escherichia coli, and purified using reverse phase high performance liquid chromatography (RP-HPLC) after digestion with enterokinase. Structural analysis of the parent protein and representative mutants in solution by CD showed no detectable differences in their folding structures. The binding affinity of the mutants to BMP-4 was determined by surface plasmon resonance biosensor. All the mutant receptors examined, with the exception of Y70A, displayed reduced affinities to BMP-4 with the rank order of decreases: I52A (17-fold) approximately F75A (15-fold) >> T64A (4-fold) = T62A (4-fold) approximately E54A (3-fold). The decreases in binding affinity observed for the latter three mutants are mainly due to decreased association rate constants while alterations in rate constants both, for association and dissociation, result in the drastically reduced affinities for the former two mutants. These results allow us to conclude that sBMPR-IA recognizes the ligand using the concave face of the molecule. The major ligand-binding site of the BMP type IA receptor consists of Phe75 in loop 2 and Ile52, Glu54, Thr62 and Thr64 on the three-stranded beta-sheet. These findings should provide a general basis for the ligand/type I receptor recognition in the TGF-beta superfamily.

Molecular cloning and expression profile of Xenopus calcineurin A subunit(1)

We have cloned a cDNA encoding a catalytic subunit of calcineurin (CnA) expressed in Xenopus oocytes. The deduced amino acid sequence indicates 96.3% and 96.8% identities with the mouse and human CnAalpha isoforms, respectively. Xenopus CnA (XCnA) RNA and protein are expressed as maternal and throughout development. Recombinant XCnA protein interacted with calmodulin in the presence of Ca(2+). Deletion of calmodulin binding domain and auto-inhibitory domain revealed calcium independent phosphatase activity, thereby showing that XCnA is likely to be modulated by both calmodulin and calcium.

Induction of apoptosis in human cancer cells by TZT-1027, an antimicrotubule agent

TZT-1027, a newly synthesized dolastatin 10 derivative, is a potent antitumor agent which inhibits microtubule polymerization and perturbs microtubule dynamics. In this report, we investigated whether TZT-1027 inhibited the growth of various human cancer cells, and the cell death caused by TZT-1027 was due to apoptosis. In addition, we elucidated the apoptosis machinery induced by treatment with TZT-1027. The 50% growth-inhibitory concentrations (IC50 values) of TZT-1027 on cancer cells derived from various sources were not more than 5.9 ng/ml. TZT-1027 showed superior cytotoxicity than any other antitumor agents. Next, we evaluated morphological nuclear change, namely, chromatin condensation and DNA fragmentation. We used three cancer cell lines derived from different types in view of having apoptosis related protein, human leukemia HL-60 (in the presence of both Caspase-3 and Bcl-2), human breast cancer MCF-7 (in the absence of Caspase-3), and human prostate cancer DU145 (in the absence of Bcl-2). TZT-1027 induced DNA fragmentation in the presence but not absence of Caspase-3. Nevertheless, apoptic chromatin condensation was observed in all cancer cells even if there was no Caspase-3. Furthermore, we examined whether TZT-1027, microtubule-disrupting agent, influenced cell cycle progression. Flow cytometric analysis revealed the cells treated with TZT-1027, and with the other antimicrotubule agents, to be arrested at the G2/M phase and subsequently to show fragmented DNA smaller than that of G1 phase cells. Moreover, we tested TZT-1027 for its ability to induce Bcl-2 phosphorylation in human cancer cell lines. TZT-1027 and other agents which interacted with microtubules induced Bcl-2 phosphorylation, whereas DNA-damaging agents did not. The present results suggested an association of the growth-inhibitory effect of TZT-1027 with the induction of apoptosis and indicated that the apoptosis induced by TZT-1027 was followed by G2/M arrest even if there was no Caspase-3 or Bcl-2.

Combination of biomolecular interaction analysis and mass spectrometric amino acid sequencing

We describe an approach for the combination of biomolecular interaction analysis (BIA) and electrospray tandem mass spectrometry (ESI/MS/MS) to obtain sequence information on the affinity-bound proteins on the sensor chip of BIA. The procedure is illustrated with stable and unstable interactions of recombinant proteins, i.e., histidine-tagged protein-Ni2+/NTA and 1,4,5-inositol trisphosphate receptor-ligand interactions. The E. coli lysates expressing the recombinant proteins were passed through the sensor chips, and biomolecular interactions were monitored in real time. The molecules detected on the sensor chip were digested by delivering proteolytic enzyme to the sensing flow cells. The resulting on-chip digested peptide mixture at the mid- to low-femtomole level was recovered on a microcapillary reversed-phase precolumn by an on-line system and analyzed using HPLC-MS/MS. In both cases, unambiguous sequence information on the recombinant proteins isolated on the sensor chip was obtained from only a single run of analysis. The combined BIA-MS/MS may prove to be a general and versatile system to discover novel biomolecular interactions and to analyze protein complexes.

TZT-1027, an antimicrotubule agent, attacks tumor vasculature and induces tumor cell death

TZT-1027, a dolastatin 10 derivative, is an antimicrotubule agent with potent antitumor activity both in vitro and in vivo. In this study, we performed biochemical and histopathological examinations, and evaluated TZT-1027-induced tumoral vascular collapse and tumor cell death in an advanced tumor model, murine colon 26 adenocarcinoma. In addition, we studied the effects of TZT-1027 on cultured human umbilical vein endothelial cells (HUVEC). Tolerable doses of TZT-1027 induced tumor-selective hemorrhage within 1 h. This hemorrhage occurred mainly in the peripheral area of the tumor mass. Measurements of tumoral hemoglobin content and dye permeation revealed that the hemorrhage occurred firstly and tumor blood flow stopped secondarily. The vascular damage was followed by continuous induction of apoptosis of the tumor cells, tumor tissue necrosis, and tumor regression. In cultured HUVEC, TZT-1027 induced marked cell contraction with membrane blebbing in 30 min. These cell changes were completely inhibited by K252a, a broad-spectrum inhibitor of protein kinases. These effects of TZT-1027 on both tumor vasculature and HUVEC were greater than those of vincristine. In conclusion, TZT-1027 quickly attacked the well-developed vascular system of advanced tumors by a putative protein kinase-dependent mechanism, and then blocked tumor blood flow. Therefore, TZT-1027 has both a conventional antitumor activity and a unique anti-tumoral vascular activity, making it a potentially powerful tool for clinical cancer therapy.

Characterization of the interaction of TZT-1027, a potent antitumor agent, with tubulin

TZT-1027, a derivative of dolastatin 10 isolated from the Indian Ocean sea hare Dolabella auricularia in 1987 by Pettit et al., is a potent antimicrotubule agent. We have compared the activity of TZT-1027 with that of dolastatin 10 as well as the vinca alkaloids vinblastine (VLB), vincristine (VCR) and vindesine (VDS). TZT-1027 and dolastatin 10 inhibited microtubule polymerization concentration-dependently at 1 - 100 microM with IC50 values of 2.2 +/- 0.6 and 2.3 +/- 0.7 microM, respectively. VLB, VCR and VDS inhibited microtubule polymerization at 1 - 3 microM with IC50 values of 2.7 +/- 0.6, 1.6 +/- 0.4 and 1.6 +/- 0.2 microM, respectively, but showed a slight decrease in inhibitory effect at concentrations of 10 microM or more. TZT-1027 also inhibited monosodium glutamate-induced tubulin polymerization concentration-dependently at 0.3 - 10 microM, with an IC50 of 1.2 microM, whereas VLB was only effective at 0.3 - 3 microM, with an IC50 of 0.6 microM, and caused so-called "aggregation" of tubulin at 10 microM. Scatchard analysis of the binding data for [(3)H]VLB suggested one binding site (Kd 0.2 +/- 0.04 microM and Bmax 6.0 +/- 0.26 nM / mg protein), while that for [(3)H]TZT-1027 suggested two binding sites, one of high affinity (Kd 0.2 +/- 0.01 microM and Bmax 1.7 +/- 0.012 nM / mg protein) and the other of low affinity (Kd 10. 3 +/- 1.46 microM and Bmax 11.6 +/- 0.83 nM / mg protein). [(3)H]TZT-1027 was completely displaced by dolastatin 10 but only incompletely by VLB. [(3)H]VLB was completely displaced by dolastatin 10 and TZT-1027. Furthermore, TZT-1027 prevented [(3)H]VLB from binding to tubulin in a non-competitive manner according to Lineweaver-Burk analysis. TZT-1027 concentration-dependently inhibited both [(3)H]guanosine 5'-triphosphate (GTP) binding to and GTP hydrolysis on tubulin. VLB inhibited the hydrolysis of GTP on tubulin concentration-dependently to a lesser extent than TZT-1027, but no inhibitory effect of VLB on [(3)H]GTP binding to tubulin was evident even at 100 microM. Thus, TZT-1027 affected the binding of VLB to tubulin, but its binding site was not completely identical to that of VLB. TZT-1027 had a potent inhibitory effect on tubulin polymerization and differed from vinca alkaloids in its mode of action against tubulin polymerization.

[Clinical significance of serum p53 antibody detection in a chemosensitivity assay in cases of human colorectal cancer]

Alteration of the p53 gene product occurs frequently during the progression of colorectal cancer. Recently, mutated p53 protein was found to induce the production of anti-p53 antibodies in the serum of patients. The purpose of this study was to evaluate the relationship between p53 status in serum and chemosensitivity in resectable colorectal cancer patients. A total of 35 patients with primary colorectal cancer who underwent surgical treatment were examined by chemosensitivity test with the viable tumor samples using Histoculture Drug Response Assay (HDRA). Serum samples of these patients to test for p53 antibodies were obtained before tumor resection, and assayed in duplicate by using an enzyme-linked immunosorbent assay (ELISA) kit. The inhibition index of 5-FU and CDDP, determined by the HDRA method, in the sero-positive group was significantly lower than that of the sero-negative group (p < 0.01). Furthermore, significant statistical differences in chemosensitivity to 5-FU and CDDP were revealed depending on the presence of serum p53 antibodies. There was no relationship between chemosensitivity assay and tumor marker positivity or clinicopathological features in these patients. Detection of serum p53 antibodies, which reflects p53 mutations in tumor tissue, is a simple method which correlates with chemosensitivity, and may contribute to the selection of favorable chemotherapeutic strategies of colorectal cancer.

Clinical significance of serum vascular endothelial growth factor in colorectal cancer patients: correlation with clinicopathological factors and tumor markers

Vascular endothelial growth factor (VEGF) is known as a potent inducer of angiogenesis in various human cancers. Serum VEGF concentrations of colorectal cancer patients was assessed for their clinical significance as a tumor marker. Serum samples were obtained at admission from 24 healthy volunteers and 111 patients with colorectal cancer. Preoperative serum VEGF concentrations, which are significantly higher than those of healthy controls, reflect clinical stage progression, depth of invasion, liver metastasis, lymph node metastasis and lymphatic invasion. Consequently, detection of VEGF could serve as a clinically useful marker for colorectal cancer progression and metastasis independent of other markers.

Clinical significance of serum vascular endothelial growth factor in colorectal cancer patients: correlation with clinicopathological factors and tumor markers

Vascular endothelial growth factor (VEGF) is known as a potent inducer of angiogenesis in various human cancers. Serum VEGF concentrations of colorectal cancer patients was assessed for their clinical significance as a tumor marker. Serum samples were obtained at admission from 24 healthy volunteers and 111 patients with colorectal cancer. Preoperative serum VEGF concentrations, which are significantly higher than those of healthy controls, reflect clinical stage progression, depth of invasion, liver metastasis, lymph node metastasis and lymphatic invasion. Consequently, detection of VEGF could serve as a clinically useful marker for colorectal cancer progression and metastasis independent of other markers.

Anatomy of the right anterosuperior area (segment 8) of the liver: evaluation with helical CT during arterial portography

PURPOSE

To evaluate the segmental anatomy of the right anterosuperior area (segment 8) of the liver by using helical computed tomography during arterial portography (CTAP).

MATERIALS AND METHODS

Twenty-seven patients without lesions at segment 8 underwent helical CTAP. Three-dimensional portograms were reconstructed to verify the course of the portal veins. The number of subsegmental branches, in addition to the branching point and the distribution in segment 8, was assessed.

RESULTS

In 25 (93%) patients, the dorsal branch of segment 8 gave rise to dorsally directed branches posterior to the right hepatic vein. In only four (25%) of 16 patients in whom the medial branch of segment 8 arose near the porta hepatis, the long paracaval portal branch of the caudate lobe extended upward above the interval between the middle and right hepatic veins.

CONCLUSION

In most of the patients, the dorsal branches of segment 8 supplied the dorsocranial area of the right lobe posterior to the right hepatic vein. The paracaval portion of the caudate lobe was limited to below the interval between the middle and right hepatic veins in the majority of patients who showed medial branches of segment 8 arising near the porta hepatis. Recognition of this vascular anatomy is clinically important for preoperative evaluation of hepatic tumors in segment 8 because it may contribute to a safer surgical approach.

[Detection of serum p53 antibodies in colorectal cancer patients and the clinical significance of postoperative monitoring]

p53 protein overexpression was found to induce the production of antibodies in patient serum and, recently, the easy detection of serum antibodies has been made possible. The aim of this study is to determine the significance of serum p53 antibodies in patients with primary colorectal adenocarcinoma in comparison with their clinicopathological features, and the tumor marker sensitivities of carcinoembryonic antigen (CEA), carcinoma antigen 19-9 (CA19-9) and alpha-fetoprotein (AFP). Thirty-nine of 86 patients (45.3%) were positive for serum p53 antibodies. However, there was no relation with the cancer progression or clinicopathological findings. The sensitivities of CEA, CA19-9 and AFP were 36.0%, 38.4%, and 8.1% respectively, but there was no relation between serum p53 antibodies and these three markers. When the sensitivity of serum p53 antibodies and CEA was evaluated according to clinical stage, the presence of serum p53 antibodies was more significantly associated with stage 0, I and II colorectal cancer than was CEA. Thirty-three patients who showed preoperative positivity for serum p53 antibodies were followed by serial evaluation of circulating antibodies after resection. Negative conversions after resection were significantly higher in the "Cur A" group than in the "Cur B" or "Cur C" groups. Serum p53 antibodies appear to be a useful tumor marker independent of the other markers, especially in the early stage, and are expected to be useful in the development of a method of early diagnosis for mass screening, and as a postoperative monitoring marker for colorectal cancer.

Stimulus-coupled interaction of tyrosine hydroxylase with 14-3-3 proteins

Tyrosine hydroxylase (TH) is phosphorylated by CaM kinase II and is activated in situ in response to a variety of stimuli that increase intracellular Ca(2+). We report here, using baculovirus-expressed TH, that the 14-3-3 protein binds and activates the expressed TH when the enzyme is phosphorylated at Ser-19, a site of CaM kinase II-dependent phosphorylation located in the regulatory domain of TH. Site-directed mutagenesis showed that a TH mutant in which Ser-19 was substituted by Ala retained enzymatic activity at the same level as the non-mutated enzyme, but was a poor substrate for CaM kinase II and did not bind the 14-3-3 protein. Likewise, a synthetic phosphopeptide (FRRAVpSELDA) corresponding to the part of the TH sequence, including phosphoSer-19, inhibited the interaction between the expressed TH and 14-3-3, while the phosphopeptide (GRRQpSLIED) corresponding to the site of cAMP-dependent phosphorylation (Ser-40) had little effect on complex formation. The complex was very stable with a dissociation constant of 3 nM. Furthermore, analysis of PC12nnr5 cells transfected with myc-tagged 14-3-3 showed that 14-3-3 formed a complex with endogenous TH when the cultured cells were exposed to a high K(+) concentration that increases intracellular Ca(2+) and phosphorylation of Ser-19 in TH. These findings suggest that the 14-3-3 protein participates in the stimulus-coupled regulation of catecholamine synthesis that occurs in response to depolarization-evoked, Ca(2+)-dependent phosphorylation of TH.

[Activity of a novel antitumor agent, TZT-1027]

We studied the antitumor activity of newly synthesized dolastatin 10 analogs. TZT-1027 showed remarkable activity and was selected for further development. TZT-1027 was found to inhibit the assembly of porcine brain microtubule proteins and to depolymerize the polymerized microtubule proteins. Therefore, its mechanism of antitumor activity seems to be at least partially ascribed to the inhibition of microtubule assembly. We further studied the binding site of TZT-1027 on tubulin. Scatchard analysis of 3H-TZT-1027 binding data suggested two binding sites including a high affinity site and a low affinity site. TZT-1027 affected the binding of vinblastine (VBL) on tubulin but its binding site isn't identical to the VBL binding site. TZT-1027 induced apoptosis within 24 h, not only in human leukemia cells such as HL-60, but also in solid tumors such as human prostate carcinoma cells DU145 and human mammary carcinoma cells MCF-7. TZT-1027 showed good antitumor activity against human xenografts (MX-1 and LX-1) without causing serious body weight reduction, which resulted in tumor regression. We examined the effect of TZT-1027 on the established tumor vasculature using the dye perfusion into tumor. TZT-1027 exhibited considerable antivascular activity in tumor sections in addition to excellent cytotoxic effect.

Calmodulin inhibits inositol 1,4,5-trisphosphate-induced calcium release through the purified and reconstituted inositol 1,4,5-trisphosphate receptor type 1

Our previous studies have demonstrated that calmodulin binds to IP3R type I (IP3R1) in a Ca2+ dependent manner, which suggests that calmodulin regulates the IP3R1 channel. In the present study, we investigated real-time kinetics of interactions between calmodulin and IP3R1 as well as effects of calmodulin on IP3-induced Ca2+ release by purified and reconstituted IP3R1. Kinetic analysis revealed that calmodulin binds to IP3R1 in a Ca2+ dependent manner and that both association and dissociation phase consist of two components with time constants of k(a) = 4.46 x 10(2) and > 10(4) M(-1) s(-1) k(d) = 1.44 x 10(-2) and 1.17 x 10(-1) s(-1). The apparent dissociation constant was calculated to be 27.3 microM. The IP3-induced Ca2+ release through the purified and reconstituted IP3R1 was inhibited by Ca2+/calmodulin, in a dose dependent manner. We interpret our findings to mean that calmodulin binds to IP3R1 in a Ca2+ dependent manner to exert inhibitory effect on IP3R channel activity. This event may be one of the mechanisms governing the negative feedback regulation of IP3-induced Ca2+ release by Ca2+.

Real time analysis of interaction between inositol 1,4, 5-trisphosphate receptor type I and its ligand

Inositol 1,4,5-trisphosphate (IP(3)) is an important second messenger that releases intracellular Ca(2+) by binding to its specific receptor, inositol 1,4,5-trisphosphate receptor (IP(3)R), in a wide range of cellular processes. We report here large-scale expression and purification of N-terminal 604 amino acids of IP(3)R type 1 (T604) expressed in E. coli, which contains the ligand binding domain. Surface plasmon resonance biosensor studies showed that purified T604 could bind to its ligands with binding specificity identical to that of full-length native IP(3)R type 1. Kinetic parameters of T604 for IP(3) consisted of a fast association rate constant (K(ass) = 1.2 x 10(6) M(-1) s(-1)) and a rapid dissociation rate constant (k(diss) = 1 s(-1)), and the equilibrium dissociation constant was determined to be 336 nM, at 150 mM NaCl and pH 7.4. However, association and dissociation patterns depended on the pH level and ionic strength. These results pave the way toward detail analysis of structure-function analysis of the ligand binding domain of IP(3)R type 1 for its ligands.

Drainage area of the head of the pancreas by computed tomography under endoscopic retrograde pancreatography (ERP-CT)

BACKGROUND/AIMS

This study evaluated the drainage area of the capitular branches of the pancreas head by computed tomography under endoscopic retrograde pancreatography (ERP-CT).

METHODOLOGY

ERP-CT was performed in 43 patients. The drainage area of the capitular branches of Wirsung's and Santorini's ducts were evaluated by dividing the pancreatic head into two areas, the anterior area and the posterior area.

RESULTS

The pancreatic duct pattern was classified in 4 types; normal type, ansa type, loop type, and embryonic type. In normal type duct pattern, all inferior capitular branches of Wirsung's duct drained the posterior area and all inferior capitular branches of Santorini's duct drained the anterior area. In ansa type duct pattern, all inferior branches from Wirsung's duct drained the posterior area and inferior branches from Santorini's duct drained the anterior area and the posterior area. In loop type duct pattern, all inferior branches from Santorini's duct drained the posterior area and inferior branches from Wirsung's duct drained the anterior area and the posterior area. Middle capitular branches were detected only in normal B, normal C, and loop type.

CONCLUSIONS

ERP-CT is a useful procedure that provided three-dimensional morphology of the capitular branch of the pancreas head.

Direct binding of follistatin to a complex of bone-morphogenetic protein and its receptor inhibits ventral and epidermal cell fates in early Xenopus embryo

In early development of Xenopus laevis, it is known that activities of polypeptide growth factors are negatively regulated by their binding proteins. In this study, follistatin, originally known as an activin-binding protein, was shown to inhibit all aspects of bone morphogenetic protein (BMP) activity in early Xenopus embryos. Furthermore, using a surface plasmon resonance biosensor, we demonstrated that follistatin can directly interact with multiple BMPs at significantly high affinities. Interestingly, follistatin was found to be noncompetitive with the BMP receptor for ligand binding and to form a trimeric complex with BMP and its receptor. The results suggest that follistatin acts as an organizer factor in early amphibian embryogenesis by inhibiting BMP activities by a different mechanism from that used by chordin and noggin.

Hydrophilic surroundings requisite for the solubilization of proteins related with their hydrophobicity in the AOT reversed micellar extraction

The reversed micellar extraction (AOT/isooctane system) using the phase transfer method was investigated in relation to the AOT concentration and the water solubilization for ribonuclease A, lysozyme and cytochrome c. The minimal AOT concentration required for 100% forward extraction was obtained for these proteins. At the minimal AOT concentration, the hydrophilic surroundings, i.e. the molar ratio of water to extracted protein in the organic phase, were independent of the protein concentration for each protein. The hydrophilic surroundings of these proteins were linearly related with Fisher's polarity ratio, p, as an index of the hydrophobicity of the protein. Using this linear relation, a procedure to estimate the sufficient AOT concentration for the protein extraction was proposed. In the cases of cytochrome c and lysozyme, the water concentration was larger than that in the protein-free system in spite of the same AOT condition. On the contrary, in the case of ribonuclease A, this large water uptake in the organic phase was not observed. These differences of water uptake were discussed in relation to the location of the protein in the AOT reversed micelles.

Molecular cloning of a pig homologue of membrane cofactor protein (CD46)

Organs of transgenic pigs that express human complement regulatory proteins are under assessment as an alternative to transplantation. A major barrier to the transplantation of pig organs is the hyperacute rejection caused by pre-existing antibodies and complement. Pig cells are very susceptible to human complement, presumably because pig cell-surface complement regulatory proteins are inefficient against it. Expression of human complement regulatory proteins, such as decay-accelerating factor and membrane cofactor proteins (MCP or CD46), by means of transgenes would confer resistance to human complement upon pig cells, thereby preventing hyperacute rejection. To express sufficient levels of human complement regulatory proteins at appropriate sites, regulatory elements of genes of pig membrane-bound complement regulatory proteins would be useful. To obtain their cDNAs, we transfected human cells with a pig cDNA library, selected cells by incubation with pig complement and rescued the plasmids. We cloned a cDNA for the pig homologue of MCP, pMCP. The cDNA encoded a predicted protein of 363 amino acids with 42% amino acid identity with human MCP. The pMCP consisted of four short consensus repeats, a Ser/Thr/Pro-rich domain, and transmembrane and cytoplasmic domains. Recombinant soluble pMCP that lacked transmembrane and cytoplasmic domains had factor I cofactor activity in C3b cleavage, indicating that it is functionally, as well as structurally homologous to MCP. FACS analysis with anti-pMCP mAb demonstrated that pMCP is expressed on all blood leukocytes, erythrocytes, and on endothelial and epithelial cell lines.

Synoviocyte proliferation in joints of SCID mice induced by toxic shock syndrome toxin-1 stimulated T cells from patient with rheumatoid arthritis

OBJECTIVE

To investigate the histopathological arthropathy in severe combined immunodeficient (SCID) mice given intraarticular injection of toxic shock syndrome toxin-1 (TSST-1) stimulated T cells from patients with rheumatoid arthritis (RA).

METHODS

Unstimulated or TSST-1 stimulated T cell blasts (TB-TSST) of synovial fluid mononuclear cells from patients with RA (RASFMC) were intraarticularly injected into the knee joint of SCID mice. Four weeks later, the knee joints were histopathologically examined and the numbers of fibroblasts in the synovial tissues were compared with those of controls. Total RNA of the SCID mouse knee joints was isolated and Southern analysis for human T cell receptor (TCR) V beta 2 and human tumor necrosis factor-alpha (TNF-alpha) was carried out.

RESULTS

Hyperplasia and increased numbers of the fibroblasts as well as neovascularization of the synovial tissues were observed in the SCID mouse knee joint tissues injected with TB-TSST of RASFMC compared with those injected with unstimulated T cells from RASFMC or with TB-TSST from peripheral blood of healthy controls. Messenger RNA for human TCR V beta 2 and TNF-alpha were detected in the SCID mouse knee joint tissues injected with TB-TSST from RASFMC.

CONCLUSION

Superantigen TSST-1 stimulated T cells from RASFMC have the ability to induce chronic arthropathy with fibroblast proliferation and neovascularization in the SCID mouse.

Interaction between soluble type I receptor for bone morphogenetic protein and bone morphogenetic protein-4

Bone morphogenetic proteins (BMPs) are multifunctional proteins that comprise the largest subfamily of the transforming growth factor-beta. These proteins bind to types I and II serine/threonine kinase receptors. Ligand-induced heteromeric dimerization of these receptors is the key event in initiation of biological responses. We report here large-scale expression and purification of extracellular domain of the type I receptor for BMP-2/4, using a silkworm expression system. This soluble form of BMP receptor (sBMPR) was in monomer form in solution and bound to BMP-4 but not to activin or transforming growth factor-beta1. Surface plasmon resonance studies showed that kinetic parameters of sBMPR for BMP-4 consisted of a relatively rapid association rate constant (ka = 3.81 +/- 0.19 x 10(4) s-1 M-1) and an extremely slow dissociation rate constant (kd = 3.69 +/- 0.26 x 10(-4) s-1). From these two kinetic parameters, affinity was determined to be similar to that of the intact membrane-associated receptor expressed on COS cells. sBMPR inhibited the alkaline phosphatase activity in BMP responsive cell lines such as mouse osteoblastic cell MC3T3-E1 and bone marrow stromal cell ST2. These data indicate that the extracellular domain of type I receptor for BMP-2 and BMP-4 is sufficient for high-affinity binding to its ligands and should prove useful in understanding the role of BMP-2/4 in vivo, because a suitable high-affinity anti-BMP antibody has yet to be developed.

Comparison of clinical features and survival in patients with hepatitis B and C virus-related hepatocellular carcinoma

We analyzed the clinical characteristics and survival of 185 patients with hepatitis B virus-related hepatocellular carcinoma (HBV group) and 1033 with hepatitis C virus-related hepatocellular carcinoma (HCV group) by multi center study. The patients in the HBV group (mean age 52.1 yr) were about 10 years younger than those in the HCV group (mean age 62.9 yr). Liver function, as measured by indocyanine green retention at 15 min, was better in the HBV group (17.5%) than in the HCV group (25.4%). A higher proportion of the HBV group (55%) than the HCV group (44%) had clinical stage I, T-factor differed significantly between the groups: 53% of the HBV group were T3-4 compared with 41% of the HCV group. Furthermore, a higher proportion of the HBV group were graded 2-3 for tumor thrombus in the portal vein (20.3%) and had poorly differentiated hepatocellular carcinoma (7%) compared with the HCV group (7.1% and 5% respectively). Univariate analysis identified poor prognostic factors for hepatocellular carcinoma as HBV, age < or = 50 yr, clinical stage II-III, a high AFP level, higher number of tumors, larger tumor size, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3. On multivariate analysis, poor prognostic factors were a high AFP level, higher number of tumors, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3, but not HBV, age, clinical stage or tumor size. These results suggest that HBV itself is not a stronger prognostic factor than HCV.

Antitumor activity of TZT-1027, a novel dolastatin 10 derivative

Dolastatin 10, a pentapeptide isolated from the marine mollusk Dolabella auricularia, has antitumor activity. TZT-1027, a dolastatin 10 derivative, is a newly synthesized antitumor compound. We evaluated its antitumor activity against a variety of transplantable tumors in mice. Intermittent injections of TZT-1027 were more effective than single or repeated injections in mice with P388 leukemia and B16 melanoma. Consequently, TZT-1027 shows schedule dependency. TZT-1027 was effective against P388 leukemia not only when administered i.p., but also when given i.v. However, although TZT-1027 given i.v. was active against murine solid tumors, TZT-1027 administered i.p. was ineffective against all the tumors tested with the exception of colon 26 adenocarcinoma. The i.v. injection of TZT-1027 at a dose of 2.0 mg/kg remarkably inhibited the growth of three murine solid tumors; colon 26 adenocarcinoma, B16 melanoma and M5076 sarcoma, with T/C values of less than 6%. The antitumor activities of TZT-1027 against these tumors were superior or comparable to those of the reference agents; dolastatin 10, cisplatin, vincristine, 5-fluorouracil (5-FU) and E7010. In experiments with drug-resistant P388 leukemia, TZT-1027 showed good activity against cisplatin-resistant P388 and moderate activity against vincristine- and 5-fluorouracil-resistant P388, but no activity against adriamycin-resistant P388. TZT-1027 was also effective against human xenografts, that is, tumor regression was observed in mice bearing MX-1 breast and LX-1 lung carcinomas. TZT-1027 at 10 microM almost completely inhibited the assembly of porcine brain microtubules. Therefore, its mechanism of antitumor action seems to be, at least in part, ascribable to the inhibition of microtubule assembly. Because of its good preclinical activity, TZT-1027 has been entered into phase I clinical trials.

Functional nerve growth factor receptor in von Recklinghausen neurofibromatosis: an immunocytochemical and short-term culture study

Immunocytochemistry reveals 75 kDa low affinity type nerve growth factor receptor (NGFR) on the cell membrane of human neurofibroma cells of von Recklinghausen disease in vivo and in vitro. NGF-immunoreactivity is detected in the primary and cultured tumor cells. Growth augmentation of cultured neurofibroma cells by exogenous NGF is also confirmed. Phosphotyrosine-immunoreactivity is demonstrated by immunocytochemistry in the in vivo and in vitro neurofibroma cells suggesting possible phosphorylation of tyrosine residue in the NGFR or a cellular protein downstream of signal transduction through the ligand receptor system. These results indicate human neurofibroma cells possess functional NGFR and the growth is potentiated through the NGF-NGFR system in the paracrine and/or autocrine fashion.

Synthesis and antitumor activity of novel dolastatin 10 analogs

Dolastatin 10 (1) is a potent antineoplastic pentapeptide. Novel dolastatin 10 analogs each modified at one of the constituent amino acid derivatives, were synthesized and their antitumor activity was evaluated against P388 leukemia in mice. The structural requirements for antitumor activity are discussed. Some of the analogs, 31c, 35c, 38b, and 50c showed excellent activity in vivo. Highly active 50c, which lacks the thiazole group of 1, was selected for further development as an antitumor agent.

Differential effects of an alpha 1-blocker (doxazosin) on diurnal blood pressure variation in dipper and non-dipper type hypertension

A study was conducted to determine whether sympathetic nerve activity, one of the main regulators of blood pressure, is involved in high blood pressure in the night-time and morning. Twenty-seven untreated hypertensive subjects, in whom hypertension was diagnosed by ambulatory blood pressure (ABP) measurement, who showed a 24 h systolic ABP value over 140 mmHg and/or 24 h diastolic ABP over 90 mmHg were recruited. They also showed a night-time systolic ABP value of over 130 mmHg and/or a night-time diastolic ABP of over 80 mmHg. They were divided into two groups: "dippers (D)" whose night-time ambulatory blood pressure fell by more than 10% of the day-time blood pressure, and "non-dippers (ND)" in whom this phenomenon was absent. We examined the effect of a long-acting alpha 1-blocker (doxazosin) on diurnal blood pressure variation in these subjects with essential hypertension. Baseline casual blood pressure and 24 h systolic ABP were not significantly different between the two groups. However, both night-time and morning ABP in ND were higher than those in D. Administration of doxazosin (mean 73 +/- 13 (SE) d) significantly decreased casual blood pressure, and 24 h, day-time, night-time and morning systolic ABP in the whole cohort. When subjects were divided into D and ND, the day-time and morning systolic ABP decreased significantly after doxazosin treatment in both groups, whereas the night-time systolic ABP decreased significantly only in ND but not in D. These results suggest that sympathetic nerve activity involved in elevating blood pressure during the night may differ between D and ND.

Interactions between collagen-binding stress protein HSP47 and collagen. Analysis of kinetic parameters by surface plasmon resonance biosensor

A 47-kDa heat shock protein (HSP47) is a collagen-binding stress protein which is localized in the endoplasmic reticulum (ER) of collagen-secreting cells. Recent studies have shown that HSP47 transiently binds to newly synthesized procollagens and that conformationally abnormal procollagen is also bound by HSP47 for a much longer time in the ER (Nakai, A., Satoh, M., Hirayoshi, K., and Nagata, K. (1992) J. Cell Biol. 117, 903-914). HSP47 is thus suggested to have a collagen-specific molecular chaperone-like function. In this report, we analyzed the interaction of HSP47 and types I to V collagen using BIAcore system, an optical biosensor based on the principles of surface plasmon resonance. Types I-V collagen were purified from porcine skin, porcine articular cartilage, bovine lens capsule, and porcine placenta and immobilized on sensorchips of the BIAcore system at a surface concentration of 10-15 ng/mm2. Purified recombinant mouse HSP47 (rmHSP47) expressed in Escherichia coli was passed over the sensorchips at a flow rate of 2 microliters/min and binding curves of rmHSP47 to collagens were monitored. Using this approach, accurate association and dissociation rate constants were determined in addition to dissociation constants. rmHSP47 was found to bind to types I-V collagen with similar dissociation constants of the order of 10(-7) M. This relatively low dissociation constant resulted from the rapid dissociation rate constant (kdiss > 10(-2) s-1) and considerably high (kass approximately 2 x 10(4) M-1 s-1) association rate constant. These kinetic parameters may reflect a transient interaction between HSP47 and procollagen in vivo.

Experimental study on a new tracheal prosthesis made from collagen-conjugated mesh

A new tracheal prosthesis was made from fine Marlex mesh reinforced with a continuous polypropylene spiral. The mesh and spiral were covalently grafted and further coated with pig collagen with the aim of promoting connective tissue infiltration and providing initial airtightness. Complete surgical resection and replacement of a segment (2 cm in length, three to five tracheal rings) of the cervical trachea was performed in 13 adult mongrel dogs. Two dogs died of pneumonia about 2 months after operation, and eleven dogs were killed between 3 and 26 months. The prostheses in all dogs were promptly infiltrated by the surrounding connective tissue and completely incorporated by the host trachea. Formation of respiratory epithelium, which lined the prosthetic lumen, was seen to various degrees, and, in five dogs killed at 6 months or more after reconstruction, confluent epithelialization was confirmed histologically from the upper to the lower anastomotic site of the prosthesis. Marked stenosis of the prosthetic lumen caused by excessive scar tissue growth was seen in three dogs, and ulceration on the luminal surface was seen in two dogs. These results indicate that this tracheal prosthesis is highly biocompatible and promising for the repair of tracheal defects after further investigation.