Erratum: Suppression of breast cancer-associated bone loss with osteoblast proteomes via Hsp90ab1/moesin-mediated inhibition of TGFβ/FN1/CD44 signaling: Erratum

[This corrects the article DOI: 10.7150/thno.66148.].

Suppression of breast cancer-associated bone loss with osteoblast proteomes via Hsp90ab1/moesin-mediated inhibition of TGFβ/FN1/CD44 signaling

Background: Bone is a frequent site of metastases from breast cancer, but existing therapeutic options are not satisfactory. Although osteoblasts have active roles in cancer progression by assisting the vicious bone-destructive cycle, we employed a counterintuitive approach of activating pro-tumorigenic Wnt signaling and examined the paradoxical possibility of developing osteoblast-derived tumor-suppressive, bone-protective secretomes. Methods: Wnt signaling was activated by the overexpression of Lrp5 and β-catenin in osteoblasts as well as a pharmacological agent (BML284), and the therapeutic effects of their conditioned medium (CM) were evaluated using in vitro cell cultures, ex vivo breast cancer tissues, and a mouse model of osteolysis. To explore the unconventional regulatory mechanism of the action of Wnt-activated osteoblasts, whole-genome proteomics analysis was conducted, followed by immunoprecipitation and gain- and loss-of-function assays. Results: While osteoblasts did not present any innate tumor-suppressing ability, we observed that the overexpression of Lrp5 and β-catenin in Wnt signaling made their CM tumor-suppressive and bone-protective. The growth of breast cancer cells and tissues was inhibited by Lrp5-overexpressing CM (Lrp5 CM), which suppressed mammary tumors and tumor-driven bone destruction in a mouse model. Lrp5 CM also inhibited the differentiation and maturation of bone-resorbing osteoclasts by downregulating NFATc1 and cathepsin K. The overexpression of Lrp5 upregulated osteopontin that enriched Hsp90ab1 (Hsp90 beta) and moesin (MSN) in Lrp5 CM. Hsp90ab1 and MSN are atypical tumor-suppressing proteins since they are multi-tasking, moonlighting proteins that promote tumorigenesis in tumor cells. Importantly, Hsp90ab1 immuno-precipitated latent TGFβ and inactivated TGFβ, whereas MSN interacted with CD44, a cancer stem-cell marker, as well as fibronectin 1, an ECM protein. Furthermore, Hsp90ab1 and MSN downregulated KDM3A that demethylated histones, together with PDL1 that inhibited immune responses. Conclusion: In contrast to inducing tumor-enhancing secretomes and chemoresistance in general by inhibiting varying oncogenic pathways in chemotherapy, this study presented the unexpected outcome of generation tumor-suppressive secretomes by activating the pro-tumorigenic Wnt pathway. The results shed light on the contrasting role of oncogenic signaling in tumor cells and osteoblast-derived secretomes, suggesting a counterintuitive option for the treatment of breast cancer-associated bone metastasis.

Inhibition of the Growth of Breast Cancer-Associated Brain Tumors by the Osteocyte-Derived Conditioned Medium

The brain is a common site of metastasis from advanced breast cancer but few effective treatments are available. We examined a therapeutic option with a conditioned medium (CM), focusing on the role of Lrp5 and β-catenin in Wnt signaling, and IL1ra in osteocytes. Osteocytes presented the innate anti-tumor effect and the overexpression of the above genes strengthened their action. In a mouse model, the injection of their CM inhibited mammary tumors and tumor-driven osteolysis. Importantly, Lrp5- and/or IL1ra-overexpressing osteocytes or the local administration of β-catenin-overexpressing CM markedly inhibited brain tumors. In the transport analysis, tumor-suppressing factors in CM were shown to diffuse through the skull. Mechanistically, the CM with overexpression of the above genes downregulated oncogenic genes such as MMP9, Runx2, TGFβ, and Snail in breast cancer cells. Also, the CM with β-catenin overexpression downregulated CXCL1 and CXCL5 and upregulated tumor suppressors such as LIMA1, DSP, p53, and TRAIL in breast cancer cells. Notably, whole-genome proteomics revealed that histone H4 was enriched in CM and acted as an atypical tumor suppressor. Lrp5-overexpressing MSCs were also shown to act as anti-tumor agents. Collectively, this study demonstrated the therapeutic role of engineered CM in brain tumors and the tumor-suppressing action of extracellular histone H4. The result sheds light on the potential CM-based therapy for breast cancer-associated brain metastases in a minimally invasive manner.

Preventing tumor progression to the bone by induced tumor-suppressing MSCs

Background: Advanced breast cancer metastasizes to many organs including bone, but few effective treatments are available. Here we report that induced tumor-suppressing (iTS) MSCs protected bone from metastases while un-induced MSCs did not. Methods: iTS MSCs were generated by overexpressing Lrp5, β-catenin, Snail, or Akt. Their tumor-suppressing capability was tested using a mouse model of mammary tumors and bone metastasis, human breast cancer tissues and cancer cell lines. Results: In a mouse model, the induced MSC-derived conditioned medium (MSC CM) reduced mammary tumors and suppressed tumor-induced osteolysis. Tumor-promoting genes such as CXCL2 and LIF, as well as PDL1, a blocker of T-cell-based immune responses were downregulated. Proteomics analysis revealed that heat shock protein 90 (Hsp90ab1), calreticulin (Calr) and peptidylprolyl isomerase B (Ppib), which are highly expressed intracellular proteins in many cancers, were enriched in MSC CM as atypical tumor suppressors. Thus, overexpressing selected genes that were otherwise tumorigenic rendered MSCs the tumor-suppressing capability through the atypical suppressors, as well as p53 and Trail. Notably, the inhibitory effect of Lrp5- and Akt-overexpressing MSC CMs, Hsp90ab1 and Calr presented selective inhibition to tumor cells than non-tumor cells. The development of bone-resorbing osteoclasts was also suppressed by MSC CMs. Conclusion: Collectively, the results showed an anti-tumor effect of iTS MSCs and suggested novel therapeutic approaches to suppress the progression of tumors into the bone.

Efficacy of dimethyl fumarate in Japanese multiple sclerosis patients: interim analysis of randomized, double-blind APEX study and its open-label extension

Background

Current data for the use of dimethyl fumarate (DMF) in Japanese patients with relapsing-remitting multiple sclerosis (RRMS) is limited.

Objectives

To assess the efficacy of DMF in Japanese patients with RRMS.

Methods

The phase 3, multinational APEX study (ClinicalTrials.gov identifier: NCT01838668) consisted of two parts: a 24-week double-blind part where subjects were randomized to receive DMF 240 mg or placebo twice daily in East Asian and Eastern European countries, and an open-label extension part where all subjects received DMF. The primary endpoint was the total number of new gadolinium-enhancing lesions in Weeks 12-24. In this interim analysis, we report efficacy data in the Japanese subgroup (DMF n = 56; placebo n = 58) over 72 weeks, including an extension phase.

Results

DMF reduced the total number of new gadolinium-enhancing lesions in Weeks 12-24 by 85% versus placebo (p < 0.0001). At Week 24, the annualized relapse rate was also reduced by 48% with DMF, versus placebo. DMF reduced the probability of relapse from Week 8 and was sustained. The number of gadolinium-enhancing lesions was maintained through 72 weeks.

Conclusions

DMF demonstrated sustained efficacy in this Japanese subgroup. The results were consistent with those observed in studies of DMF enrolling primarily Caucasian patients.

Manipulation of cell-sized phospholipid-coated microdroplets and their use as biochemical microreactors

Cell-sized water droplets coated by a phospholipid layer mimicking the inner surface of living cells were manipulated by laser tweezers and used as biochemical microreactors. The cell-sized phospholipid-coated microdroplets (CPMDs) consisted of a water droplet in mineral oil with a diameter of 1-100 microm and coated by 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine. We monitored the time development of biochemical reactions in a single CPMD obtained after the controlled fusion of two CPMDs containing a substrate and an enzyme, respectively. We present results on two enzymatic reactions: calcein production in the presence of esterase and green fluorescence protein expression.

Lower haemoglobin level and subsequent decline in kidney function in type 2 diabetic adults without clinical albuminuria

AIMS/HYPOTHESIS

Anaemia has been suggested to be an independent risk factor for subsequent progression of advanced diabetic nephropathy; however, the relationship between haemoglobin levels and progression of nephropathy in patients without clinical albuminuria is unknown.

METHODS

We conducted this prospective hospital-based cohort study of 464 type 2 diabetic patients (149 women and 315 men, 55+/-13 [mean+/-SD] years of age) with serum creatinine <177 micromol/l (2.00 mg/dl) and urinary albumin : creatinine ratio <300 mg/g creatinine. GFR was estimated using the equation formulated by the Modification of Diet in Renal Disease Study group, refitted for Japanese individuals. Most patients had haemoglobin concentrations in the normal range (144+/-15 g/l), only modest renal impairment (GFR: 74.8+/-14.5 ml min(-1) 1.73 m(-2)), and normal urinary albumin levels (81.5/18.5% with normo-/microalbuminuria). The primary outcome measurement was the rate of change in GFR determined by regression analysis with GFR as a function of time. Patients were followed up for a mean observation period of 5.0+/-0.9 (range: 2.5 to 6.2) years.

RESULTS

Univariate and multiple regression analyses yielded a significant association between the rate of change in GFR and baseline haemoglobin concentration. After adjusting for covariates, the rate of decline in GFR was significantly greater in patients in the lowest haemoglobin quartile (-3.27 ml min(-1) 1.73 m(-2) year(-1)) than in the third (-2.71 ml min(-1) 1.73 m(-2) year(-1), p = 0.024) and highest quartiles (-2.78 ml min(-1) 1.73 m(-2) year(-1), p = 0.046).

CONCLUSIONS/INTERPRETATION

Lower haemoglobin concentrations in type 2 diabetic patients without clinical albuminuria may be a significant predictor of subsequent decline in GFR.

Structural transition of actin filament in a cell-sized water droplet with a phospholipid membrane

Actin filament, F-actin, is a semiflexible polymer with a negative charge, and is one of the main constituents of cell membranes. To clarify the effect of cross talk between a phospholipid membrane and actin filaments in cells, we conducted microscopic observations on the structural changes in actin filaments in a cell-sized (several tens of micrometers in diameter) water droplet coated with a phospholipid membrane such as phosphatidylserine (PS; negatively charged head group) or phosphatidylethanolamine (PE; neutral head group) as a simple model of a living cell membrane. With PS, actin filaments are distributed uniformly in the water phase without adsorption onto the membrane surface between 2 and 6 mM Mg2+, while between 6 and 12 mM Mg2+, actin filaments are adsorbed onto the inner membrane surface. With PE, the actin filaments are uniformly adsorbed onto the inner membrane surface between 2 and 12 mM Mg2+. With both PS and PE membranes, at Mg2+ concentrations higher than 12 mM, thick bundles are formed in the bulk water droplet accompanied by the dissolution of actin filaments from the membrane surface. The attraction between actin filaments and membrane is attributable to an increase in the translational entropy of counterions accompanied by the adsorption of actin filaments onto the membrane surface. These results suggest that a microscopic water droplet coated with phospholipid can serve as an easy-to-handle model of cell membranes.

Severe paradoxical intracranial embolism and pulmonary emboli during hip hemiarthroplasty

Both paradoxical intracranial embolism, an intracranial arterial embolism caused by venous embolic material that has passed through a right-to-left shunt, and pulmonary arterial embolism are life-threatening complications of joint arthroplasty. We report a case of severe paradoxical intracranial embolism and pulmonary embolism that occurred during hip hemiarthroplasty.

Adhesions in the temporomandibular joint: formation and significance

BACKGROUND

Adhesions are frequently seen in the deranged temporomandibular joint (TMJ). In the early stage of the degenerative process the adhesion does not seem to be a significant factor in reduced mandibular movement. This is reversed in advanced degenerative joint disease where the adhesion requires release to achieve a satisfactory clinical result. Correlation of clinical history and findings within the joint should increase understanding of limited jaw movement.

METHODS

Arthroscopic examination of deranged TMJs was performed on 75 patients with limited jaw opening and correlated with the history of the derangement.

RESULTS

A progressive maturation of adhesion formation was observed with longer standing symptoms. A different adhesion pattern was noted with derangement caused by direct trauma on the joint.

CONCLUSIONS

Internal derangement of the TMJ is associated with formation of intra-articular adhesions. These are unlikely to be associated with reduced condyle movement in the early phase of the derangement. Later stage adhesions are more substantial and require release to achieve a satisfactory clinical outcome.

Transient left ventricular apical ballooning without coronary artery stenosis: a novel heart syndrome mimicking acute myocardial infarction. Angina Pectoris-Myocardial Infarction Investigations in Japan

OBJECTIVES

To determine the clinical features of a novel heart syndrome with transient left ventricular (LV) apical ballooning, but without coronary artery stenosis, that mimics acute myocardial infarction, we performed a multicenter retrospective enrollment study.

BACKGROUND

Only several case presentations have been reported with regard to this syndrome.

METHODS

We analyzed 88 patients (12 men and 76 women), aged 67 +/- 13 years, who fulfilled the following criteria: 1) transient LV apical ballooning, 2) no significant angiographic stenosis, and 3) no known cardiomyopathies.

RESULTS

Thirt-eight (43%) patients had preceding aggravation of underlying disorders (cerebrovascular accident [n = 3], epilepsy [n = 3], exacerbated bronchial asthma [n = 3], acute abdomen [n = 7]) and noncardiac surgery or medical procedure (n = 11) at the onset. Twenty-four (27%) patients had emotional and physical problems (sudden accident [n = 2], death/funeral of a family member [n = 7], inexperience with exercise [n = 6], quarreling or excessive alcohol consumption [n = 5] and vigorous excitation [n = 4]). Chest symptoms (67%), electrocardiographic changes (ST elevation [90%], Q-wave formation [27%] and T-wave inversion [97%]) and elevated creatine kinase (56%) were found. After treatment of pulmonary edema (22%), cardiogenic shock (15%) and ventricular tachycardia/fibrillation (9%), 85 patients had class I New York Heart Association function on discharge. The LV ejection fraction improved from 41 +/- 11% to 64 +/- 10%. Transient intraventricular pressure gradient and provocative vasospasm were documented in 13/72 (18%) and 10/48 (21%) of the patients, respectively. During follow-up for 13 +/- 14 months, two patients showed recurrence, and one died suddenly.

CONCLUSIONS

A novel cardiomyopathy with transient apical ballooning was reported. Emotional or physical stress might play a key role in this cardiomyopathy, but the precise etiologic basis still remains unclear.

Simulation of the Process of Food Destruction During the Final Occlusal Stage Using a Finite Element Non-Linear Dynamic Analysis

The purpose of this study was to evaluate food destruction in the small space between opposing teeth during the final stage of occlusion. The time related process of food destruction was simulated using a finite element non-linear dynamic analysis based on three dimensional occlusal co-ordinate data of the upper and lower teeth, masticatory movement data and occlusal force records. Food destruction was analysed in two inter-arch relationships. The first was normal occlusion (cusp-to-fossa) and the second was Angle class II (cusp-to-cusp). Food destruction was successfully demonstrated in both cases.

Does primary stenting preserve cardiac function in myocardial infarction? A case-control study. NORTH-981 investigators. Network of revascularisation therapy in Hokkaido

OBJECTIVE

To investigate whether coronary stenting limits myocardial injury and preserves left ventricular function.

DESIGN AND SETTING

Prospective multicentre case-control study of primary percutaneous transluminal coronary angioplasty (PTCA) with and without stenting, performed in seven cardiovascular centres.

SUBJECTS AND METHODS

45 consecutive patients with acute myocardial infarction who were treated with successful primary stenting (Stent group) and did not have restenosis were paired with 45 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting, also with no restenosis (POBA group).

RESULTS

In comparison with the POBA group, the Stent group-especially those patients with a left anterior descending coronary artery lesion-had a smaller hypokinesis area (mean (SD): 15. 1 (20.0) v 34.4 (24.3) chords), reduced hypokinesis area/risk area (25.2 (31.9)% v 58.8 (40.1)%), and a larger ejection fraction (63.3 (10.2)% v 51.7 (11.7)%) evaluated by quantitative left ventriculography using the centerline method. In the Stent group, the correlation between risk area and hypokinesis area was significantly shifted downward. Multiple logistic regression analysis on infarct size limitation (hypokinesis area/risk area < 50%) identified preinfarction angina in all subjects and preinfarction angina and stenting in patients with left anterior descending coronary artery lesions as explanatory factors.

CONCLUSIONS

Primary PTCA using a coronary stent is effective in preventing myocardial injury and restoring left ventricular function in patients with anterior acute myocardial infarction.

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.

Effect of addition of Orvus ES paste to frozen canine semen extender on sperm acrosomes

Using the triple-stain technique, we investigated whether sperm acrosomes in frozen canine semen were protected during freezing and thawing by addition of a surfactant, Orvus ES Paste (OEP), to the extender. Acrosomes were clearly shown to be protected by the addition of OEP to the entender when compared with those in sperm frozen without OEP addition (p<0.05).

Effects of orvus ES paste on canine spermatozoal longevity after freezing and thawing

Because of weak resistance of canine sperm to freezing, an applicable method of preparing canine frozen semen has not yet been established. We added various concentrations of Orvus ES Paste (OEP) to egg yolk Tris-fructose citrate, and investigated its effectiveness on survival of spermatozoa. Addition of 0.5-1.0% OEP to the extender for freezing canine semen was effective in prolonging post-thaw survival of spermatozoa.

Cystic hamartoma of the renal pelvis: imaging features

We report a case of a 50-year-old woman with histologically proven cystic hamartoma of the renal pelvis, focusing on the imaging findings and pathologic features. A large multicystic tumor with solid components in the left kidney was enhanced on both contrast-enhanced CT and gadolinium-enhanced MR images. Angiographic images showed irregular tumor vessels with moderate tumor stain.

Plasma LH and progesterone levels before and after ovulation and observation of ovarian follicles by ultrasonographic diagnosis system in dogs

Recently, canine frozen semen has been attracting attention for breeding purposes, and methods of judging ovulation and optimum timing for insemination have become important. As methods of predicting the canine ovulation, vaginal smear, plasma sex hormone levels and ultrasonographic diagnosis system (US) have been investigated in combination, but a standard technique has not yet been established. Therefore, we investigated a method of predicting canine ovulation in dogs by US, and by measuring plasma LH and progesterone (P) levels three times a day. Ovulation could be observed by detecting irregularly shaped ovarian follicles by US in six of 11 dogs (54.5%). In these dogs, the time between the LH peak and ovulation was 24-48 hr, 38.0 hr on average. The P level on the ovulation day was 1.88-2.81 ng/ml, 2.34 ng/ml on average. A value of 1.88 ng/ml was detected in one dog, but the other five dogs showed P levels of 2 ng/ml or higher. The P level on the day before ovulation was 0.8-1.56 ng/ml, 1.12 ng/ml on average. Assuming that ovulation occurred two days after the LH peak in the 11 experimental dogs, the P level was 2.12-4.06 ng/ml, 2.78 ng/ml on average. The period of a high LH level, not less than 10 ng/ml, continued for 12 hr around the LH peak. Based on these findings, to predict ovulation using US and LH level, it would be necessary for the tests to be performed several times a day. In contrast, it was shown that the day on which a plasma P level of 2 ng/ml or higher was detected by the test performed once a day corresponded to the ovulation day.

Mutant DnaA proteins defective in duplex opening of oriC, the origin of chromosomal DNA replication in Escherichia coli

We characterized three mutant DnaA proteins with an amino acid substitution of R334H, R342H and E361G that renders chromosomal replication cold (20 degrees C) sensitive. Each mutant DnaA protein was highly purified from overproducers, and replication activities were assayed in in vitro oriC replication systems. At 30 degrees C, all three mutant proteins exhibited specific activity similar to that seen with the wild-type protein, whereas at 20 degrees C, there was much less activity in a replication system using a crude replicative extract. Regarding the affinity for ATP, the dissociation rate of bound ATP and binding to oriC DNA, the three mutant DnaA proteins showed a capacity indistinguishable from that of the wild-type DnaA protein. Activity for oriC DNA unwinding of the two mutant DnaA proteins, R334H and R342H, was more sensitive to low temperature than that of the wild-type DnaA protein. We propose that R334H and R342H have a defect in their potential to unwind oriC DNA at low temperatures, the result being the cold-sensitive phenotype in oriC DNA replication. The two amino acid residues of DnaA protein, located in a motif homologous to that of NtrC protein, may play a role in the formation of the open complex. The E361 residue may be related to interaction with another protein present in a crude cell extract.

Role of hyperinsulinemia in atherosclerotic coronary arterial disease: studies of semi-quantitative coronary angiography

OBJECTIVE

To evaluate the role of insulin resistance on coronary atherosclerosis, angiographic semiquantitative scores of coronary stenosis and calcification were evaluated.

SUBJECTS AND METHODS

Ninety-five non-diabetic subjects with coronary arterial disease were selected from our angiographic data base. Hyperinsulinemia was defined as a serum insulin level of > or = 60.4 IU/l at 120 minutes after 75 g oral glucose challenge.

RESULTS

Twenty-three (24%) of the patients exhibited hyperinsulinemia. There was no difference in age or gender between the two subgroups. The incidence of hypertension, smoking habits, hypercholesterolemia, and hyperuricemia were also the same among the insulin resistance subgroups. Subjects with hyperinsulinemia had higher coronary artery scores of stenosis (11.9+/-5.6 vs 8.3+/-5.0, p<0.0001) and calcification (7.5+/-6.3 vs 4.8+/-4.9, p<0.0001). Moreover, the stenosis score had a close linear correlation with the 120 minutes serum insulin level (r=0.266, p=0.009), but not with the fasting level.

CONCLUSION

These results suggest that hyperinsulinemia is a risk for coronary arterial disease, and emphasize the severity of coronary atherosclerosis in normal glucose tolerant subjects.

Anomalous systemic arterial supply to normal basal segments of the left lower lobe

BACKGROUND

Anomalous arterial supply to the normal basal segments of the lower lobe without sequestration is a rare congenital abnormality, and whether it belongs to the broad spectrum of sequestration disorders remains controversial.

METHODS

The cases of all 4 patients who were treated surgically by us were reviewed together with 8 previously reported cases.

RESULTS

The anomalous artery originated from the descending thoracic aorta, distributed to the basal segments of the left lower lobe, and drained to a normal inferior pulmonary vein in each case. The anomalous artery was thick and elastic walled. From the review of all 12 cases, male gender, left side, descending thoracic aorta as the aberrant arterial origin, absence of pulmonary blood flow to the basal segments, and normal pulmonary venous drainage were predominant. Despite some differences, the findings seemed closely related to intralobar sequestration. Surgical treatments were lung resection, anastomosis, and ligation of the anomalous artery.

CONCLUSIONS

This anomaly is probably one type of sequestration complex. Both aortic and pulmonary arterial angiographic studies are needed to plan the definitive surgical procedure.

Involvement of Arg-328, Arg-334 and Arg-342 of DnaA protein in the functional interaction with acidic phospholipids

We reported previously that three basic amino acids (Arg-360, Arg-364 and Lys-372) of DnaA protein are essential for its functional interaction with cardiolipin. In this study, we examined the effect of mutation of some basic amino acids in a potential amphipathic helix (from Lys-327 to Ile-345) of DnaA protein on this interaction. ATP binding to the mutant DnaA protein, in which Arg-328, Arg-334 and Arg-342 were changed to acidic amino acids, was less inhibited by cardiolipin than that of the wild-type protein, as was the case for mutant DnaA protein with mutations of Arg-360, Arg-364 and Lys-372. A mutant DnaA protein with mutations of all six basic amino acids showed the most resistance to the inhibition of ATP binding by cardiolipin. These results suggest that Arg-328, Arg-334 and Arg-342, like Arg-360, Arg-364 and Lys-372, are also involved in the functional interaction between DnaA protein and acidic phospholipids.

Antiseptic susceptibility and distribution of antiseptic-resistance genes in methicillin-resistant Staphylococcus aureus

We examined the antiseptic susceptibilities and distribution of antiseptic-resistance genes qacA and smr in 98 isolates of methicillin-resistant Staphylococcus aureus obtained in 1992. Seventy-one strains were resistant to antiseptics. The qacA and smr genes were detected in 10 and 20 strains, respectively. The remaining 41 strains without qacA and smr were divided into two groups that exhibited low-level (n = 22) and high-level (n = 19) resistance to acriflavin. DNA cloning and sequencing suggested that norfloxacin-resistance gene norA was responsible for the high-level resistance to acriflavin. Our results indicated that four or more antiseptic-resistance genes exist in methicillin-resistant S. aureus and that antiseptic-resistant methicillin-resistant S. aureus strains without qacA and smr are widely spread in Japan.

Site-directed mutational analysis for the membrane binding of DnaA protein. Identification of amino acids involved in the functional interaction between DnaA protein and acidic phospholipids

DnaA protein, the initiator of chromosomal DNA replication in Escherichia coli, interacts with acidic phospholipids, such as cardiolipin, and its activity seems to be regulated by membrane binding in cells. In this study we introduced site-directed mutations at the positions of hydrophobic or basic amino acids which are conserved among various bacteria species and which are located in the putative membrane-binding region of DnaA protein (from Asp357 to Val374). All mutant DnaA proteins showed much the same ATP and ADP binding activity as that of the wild-type protein. The release of ATP bound to the mutant DnaA protein, in which three hydrophobic amino acids were mutated to hydrophilic ones, was stimulated by cardiolipin, as in the case of the wild-type protein. On the other hand, the release of ATP bound to another mutant DnaA protein, in which three basic amino acids were mutated to acidic ones, was not stimulated by cardiolipin. These results suggest not only that the region is a membrane-binding domain of DnaA protein but also that these basic amino acids are important for the binding and the ionic interaction between the basic amino acids and acidic residues of cardiolipin and is involved in the interaction between DnaA protein and cardiolipin.

Association of a polymorphism of the transforming growth factor-beta1 gene with genetic susceptibility to osteoporosis in postmenopausal Japanese women

Transforming growth factor-beta (TGF-beta) is both abundant in bone and an important regulator of bone metabolism. A T-->C transition at nucleotide 29 in the signal sequence region of the TGF-beta1 gene results in a Leu-->Pro substitution at amino acid position 10. The possible association of this polymorphism with bone mass and the prevalence of osteoporosis has now been investigated in a total of 287 postmenopausal women from two regions (Obu City, Aichi Prefecture, and Sanda City, Hyogo Prefecture) of Japan. A significant association of TGF-beta1 genotype with bone mass was detected in both populations; bone mineral density (BMD) at the lumbar spine was greater in individuals with the CC genotype than in those with the TT or TC genotype. The frequency of vertebral fractures was significantly lower in individuals with the CC genotype than in those with the TC or TT genotypes. For each region, multivariable logistic regression analysis revealed that the frequency of the T allele was significantly higher in subjects with osteoporosis than in controls. Also, the serum concentration of TGF-beta1 in individuals with the CC genotype was significantly higher than that in age-matched subjects with the TC or TT genotype in osteoporotic or osteopenic as well as healthy control groups. These results suggest that the T/C polymorphism of the TGF-beta1 gene is one of the genetic determinants of bone mass and that the T allele is an independent risk factor for the genetic susceptibility to osteoporosis in postmenopausal Japanese women. Thus, analysis of the TGF-beta1 genotype may be useful in the prevention and management of osteoporosis.

Fragments of amyloid beta induce apoptosis in vascular endothelial cells

Injury to cells that was triggered by fragments of amyloid beta protein (A beta) was studied in human vascular endothelial cells. A fragment of A beta containing amino acids 25-35 promoted cell death, but fragments of A beta containing amino acids 31-35 and 35-25 did not have such an effect. The fragment of A beta containing amino acids 25-35 induced cell death that was characterized as programmed cell death (apoptosis) in view of the accompanying morphological changes, the fragmentation of DNA, and the requirement for protein synthesis.

Effect of glycerol on the affinity of DnaA protein for ATP in the presence of cardiolipin

Acidic phospholipids, such as cardiolipin, decrease the affinity of DnaA protein for adenine nucleotides and can activate the inactive form of DnaA protein in vitro. In this study, we examined the effect of glycerol on the affinity of DnaA protein for ATP in the presence of cardiolipin. High concentrations of glycerol (34%) restored the affinity of DnaA protein for ATP, which was decreased by cardiolipin. Glycerol inhibited the binding of cardiolipin with DnaA protein. Glycerol had little effect on membrane fluidity, which is essential for the interaction between cardiolipin and DnaA protein, whereas it increased the Kd value of DnaA protein for ATP in the absence of cardiolipin. These results suggest that glycerol causes DnaA protein to become insensitive as to the interaction with cardiolipin by changing the conformation of the protein without altering the physical nature of the phospholipid.

The positional distribution of dioleoyl-palmitoyl glycerol influences lymph chylomicron transport, composition and size in rats

The effects of 1,3-dioleoyl-2-palmitoyl glycerol (OPO) on lymph chylomicron transport, composition and size in rats were investigated in comparison with 1,2-dioleoyl-3-palmitoyl glycerol (OOP). The OPO and OOP were prepared by enzymatic transesterification reactions. The concentrations of OPO and OOP in the preparations were 65.7 g/100 g, and the composition of fatty acids was similar for each. The OPO preparation contained triacylglycerols with 76.6% of the palmitic acid in the sn-2 position, whereas 100% of the oleic acid was esterified to the sn-2 position in the OOP preparation. Rats were infused with lipid emulsion containing 150 g/L of OPO or OOP via a stomach catheter. Lymph was collected through the mesenteric lymphatic trunk at 1-h intervals for 12 h. Collected lymph chylomicrons were analyzed for triacylglycerol, fatty acids, apolipoprotein A-I and particle size. The maximum transport rates of triacylglycerols in the OPO group were higher than those in the OOP group. The overall absorption of triacylglycerols, palmitic acid and oleic acid in the OPO group was also higher than that in the OOP group. In the chylomicrons, 60-70% of the fatty acids at the sn-2 position of the infused triacylglycerol was transported at the original position. The transport rates of dioleoyl-palmitoyl glycerol in the OPO group were higher than those in the OOP group. The transport rates of apolipoprotein A-I did not differ between groups, whereas the mean diameter of the chylomicrons in the OPO group was larger than that in the OOP group. These results indicate that OPO is absorbed and transported more effectively than OOP.

Left ventricular hypertrophy is more prominent in patients with primary aldosteronism than in patients with other types of secondary hypertension

We determined functional and morphological changes of the heart by 2-dimensional and pulse Doppler echocardiography in 20 patients with primary aldosteronism and compared the results with those in 50 healthy normotensive subjects, 12 patients with Cushing's syndrome, 9 patients with pheochromocytoma, and 47 patients with essential hypertension. All hypertensive groups had greater left ventricular mass indexes than did the normotensive group (76.9 +/- 17.2 g/m2). Despite similar age distribution, blood pressure during antihypertensive treatment, and duration of hypertension, the primary aldosteronism group had a significantly greater left ventricular mass index (152.5 +/- 42.5 g/m2) than did the Cushing's syndrome (103.4 +/- 37.5 g/m2), pheochromocytoma (122.4 +/- 28.5 g/m2), and essential hypertension (101.4 +/- 32.8 g/m2) groups. The left ventricular posterior wall thickness and interventricular septal wall thickness were significantly greater in the hypertensive groups than in the normotensive group and also significantly greater in the primary aldosteronism group than in any of the other hypertensive groups. By contrast, there were no significant differences among the four hypertensive groups in any variable of systolic or diastolic function of the heart. The results suggest that left ventricular hypertrophy is more pronounced in patients with primary aldosteronism than in patients with other forms of hypertension. It is therefore important to echocardiographically evaluate cardiac hypertrophy as a risk factor of morbidity and mortality in patients with this low renin hypertension.

[Biomechanical relationship between intercusp relation and masticatory movement during final stage of occlusion--time-course efficiency of food destruction]

The purpose of this study was to investigate the relationship between intercusp relation and masticatory movement during the occlusal phase by dynamic evaluation of the efficiency of mastication. The methods and the results were as follows: 1. Study of model The efficiency of mastication of cusp-to-cusp model A and cusp-to-fossa model B relationship models was highest in the movement from mesial to distal and from buccal to lingual sides for A and B, respectively. 2. Study of clinical data 2.1 The masticatory movement of (case-A) and of (case-B) having been evaluated, case-A, compared with case-B, had a greater anteroposterior movement, and there was little difference in the efficiency. 2.2 In postorthodontic treatment, the alteration of movement from anteroposterior to lateral direction was observed. The results indicated that the efficiency of mastication is determined not only by the static contact morphology of maxillary and mandibular teeth but also by the dynamic masticatory movement, adjusting to the morphology according to the intercusp relation of teeth. The direction of the adjusted masticatory movement compensated for the position and occlusal morphology of teeth to increase the efficiency as verified by the simulation and clinical data.