Effects of lactotripeptide ingestion and physical activity intervention on the fatigue status of middle-aged and older adults: a randomized controlled trial

This randomized controlled trial aimed to investigate the effects of eight weeks of lactotripeptide (LTP) ingestion, physical activity (PA) intervention, and combined intervention on the fatigue status of middle-aged and older adults. A total of 78 middle-aged and older adults (63 ± 8 years of age) were randomly assigned to four groups: placebo, LTP, placebo with PA intervention (placebo + PA), and LTP with PA intervention (LTP + PA). All participants ingested the placebo or LTP tablets daily (three tablets/day). The placebo + PA and LTP + PA groups participated in a weekly supervised exercise class and were instructed to increase their moderate- to vigorous-intensity PA at home. The visual analog scale, Brief Fatigue Inventory, Profile of Mood States second edition (POMS2), and Beck Depression Inventory second edition (BDI-II) were administered before and after the intervention. No significant interactions or main effects were observed between LTP ingestion and PA intervention on any of the fatigue scales. The main-effect analyses revealed that the PA intervention improved the total mood disturbance score of the POMS2 (F = 5.22, P = 0.03) and BDI-II score (F = 4.81, P = 0.03). After the post hoc paired comparisons, the total mood disturbance and BDI-II scores improved more with the combined intervention than with the PA intervention alone (percentage difference between the effect of combined intervention and PA intervention alone was 3.7% for total mood disturbance score and 13.7% for BDI-II score). The present study suggests that eight weeks of LTP ingestion and PA intervention did not have a significant effect on fatigue status. However, the PA intervention improved mood status and depressive symptoms, and these effects were enhanced by LTP ingestion.

1320Effectiveness of atrial flutter ablation line selection using SOUNDSTAR catheter

Background

Cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL) shows a high success rate and effective for patients. However, operators experience difficulties in CTI ablation in some cases and need additional ablation for repeated recurrence. We investigated whether the SOUNDSTAR® (Biosense. Webster, Diamond Barr, CA, USA) catheter would be effective to select a CTI line of high therapeutic effect.

Methods

We have investigated the anatomy of around CTI by SOUNDSTAR® catheter and decided the CTI line using the anatomical information in AFL ablation (Figure1). We assumed two CTI lines of medial and lateral line. Medial CTI (M-CTI) line was more common and shorter line. Lateral CTI (L-CTI) line was uncommon and slightly longer line. We use 3.5mm tip catheter with NxT steerable introducer. The target Ablation Index (AI) was 400, and the target VisTtag™ interval was 6 mm or less.

Results

A total 30 of AFL ablated cases were investigated retrospectively. We surveyed 15 cases in M-CTI group and 15 cases in L-CTI group. Comparing the length of CTI in all cases, the length of M-CTI line was shorter than L-CTI line (M-CTI 32.1 ± 6.6mm vs. L-CTI 38.4 ± 8.3mm, n = 30, p <0.01). The atrial wall thickness of midsection and tricuspid valve (TV) side were thicker in M-CTI line (Midsection: M-CTI 4.0 ± 1.2mm vs. L-CTI 3.3 ± 0.8mm, n = 30, p <0.05, TV side: M-CTI 5.4 ± 1.4mm vs. L-CTI 4.3 ± 1.1mm, n = 30, p <0.05,). There was no difference in the required number of points to complete initial line (M-CTI 8.4 ± 1.6 vs. L-CTI 8.1 ± 1.7, n = 15, ns). Eustachian ridge in IVC side was thicker and higher in the M-CTI group (3.4 ± 3.3mm vs. 0.9 ± 1.9mm, n =30, p <0.01) and ablation on the Eustachian ridge showed instability of catheter placement. A lot of RF delivery was required on Eustachian ridge in M-CTI (2.6 ± 0.6 vs. 2.1 ± 0.7, n =15, p <0.05) and AI had resulted lower in M-CTI (351 ± 42.8 vs. 381 ± 27.1, n =15, p <0.05). Recurrence is more common in M-CTI group (9/15, 60% vs. 3/15, 20%). Recurrence sites in M-CTI group were distributed ((IVC side 3/9 (33%), midsection 5/9 (56%), TV side 5/9 (56%)) and multiple recurrences occurred in 3/9 (33%). Recurrence sites in L-CTI were only midsection of CTI (3/3, 100%).

Conclusions

CTI ablation at the shorter distance M-CTI, which is commonly selected, resulted in more recurrences due to the unevenness including Eustachian ridge and the myocardium thickness. However, ablation at slightly longer L-CTI line showed lower recurrence and effective for CTI ablation.

Abstract Figure 1

Suspected Metallic Embolism following Endovascular Treatment of Intracranial Aneurysms

We describe a case series of suspected metallic embolism after coil embolization for intracranial aneurysms. Between January 2012 and December 2014, 110 intracranial aneurysms had been treated by coil embolization in our institution. In 6 cases, the postprocedural MR imaging revealed abnormal spotty lesions not detected on the preprocedural MR imaging. The lesions were also undetectable on the postprocedural CT scan. They were demonstrated as low-intensity spots on T1WI, T2WI, DWI, and T2*-weighted imaging. On DWI, they were accompanied by bright "halo," and on T2*-weighted imaging, they showed a "blooming" effect. In 3 of the 6 cases, follow-up MR imaging was available and all the lesions remained and demonstrated no signal changes. Although histologic examination had not been performed, these neuroradiologic findings strongly supported the lesions being from metallic fragments. No specific responsible device was detected after reviewing all the devices used for the neuroendovascular treatment in the 6 cases.

Recurrent peritoneal inclusion cysts successfully treated with oral contraceptives: a report of two cases

OBJECTIVE

To examine whether conservative treatment with oral contraceptives is effective in the shrinkage of a peritoneal inclusion cyst (PIC). This is a case report of two patients with a PIC that developed after gynecological surgery.

CASES

Both cases were suspected of a PIC based on the medical history, laboratory data, and image findings. It was difficult in differentiate a PIC from an ovarian tumor. Surgery was chosen at first. However, PICs in both cases recurred after surgery and were treated with oral contraceptives as a conservative treatment. PICs shrank after the treatment of oral contraceptives in both cases.

CONCLUSION

Due to the high rate of recurrence following surgery, conservative treatment is recommended to treat PICs. Hormone therapy using oral contraceptives seems to have some therapeutic benefit for the PICs.

Decontamination of outdoor school swimming pools in Fukushima after the nuclear accident in March 2011

Because of radioactive fallout resulting from the Fukushima Daiichi Nuclear Power Plant (NPP) accident, water discharge from many outdoor swimming pools in Fukushima was suspended out of concern that radiocesium in the pool water would flow into farmlands. The Japan Atomic Energy Agency has reviewed the existing flocculation method for decontaminating pool water and established a practical decontamination method by demonstrating the process at eight pools in Fukushima. In this method, zeolite powder and a flocculant are used for capturing radiocesium present in pool water. The supernatant is discharged if the radiocesium concentration is less than the targeted level. The radioactive residue is collected and stored in a temporary storage space. Radioactivity concentration in water is measured with a NaI(Tl) or Ge detector installed near the pool. The demonstration results showed that the pool water in which the radiocesium concentration was more than a few hundred Bq L was readily purified by the method, and the radiocesium concentration was reduced to less than 100 Bq L. The ambient dose rates around the temporary storage space were slightly elevated; however, the total increase was up to 30% of the background dose rates when the residue was shielded with sandbags.

C-arm CT measurement of cerebral blood volume using intra-arterial injection of contrast medium: an experimental study in canines

BACKGROUND AND PURPOSE

Measurement of perfusion parameters is typically done using an intravenous injection of contrast medium. This purpose of this study was to evaluate the feasibility of measuring regional and global CBV using C-arm CT with IA injections of contrast medium.

MATERIALS AND METHODS

Twelve canines were studied. CBV measurement was performed using standard PCT, and then using C-arm CT with IV and IA contrast. Values obtained using C-arm CT were compared with those using PCT.

RESULTS

C-arm CT CBV maps using IA injections required less contrast than ones with IV injections. PCT and C-arm CT using IV and AA injections provided comparable maps. In controls, C-arm CT with a CCA or VA injection provided comparable maps to PCT. In animals with a stroke, a CCA or VA injection did not provide maps comparable to ones made with PCT. IV and AA C-arm CT showed excellent quantitative agreement with PCT, while CCA and VA C-arm CT studies did not.

CONCLUSIONS

Measurement of global CBV using C-arm CT in conjunction with either an IV or an AA injection was feasible in controls and dogs with a stroke. Measurement of regional CBV with C-arm CT using either CCA or VA injection, in normal canines, provided CBV maps qualitatively comparable with those obtained with PCT; the absolute CBV values from these maps were in poor agreement with PCT measurements. Valid measurement of CBV using C-arm CT requires all tissue in a target region to be fully and equally opacified during any acquisition. Using CCA or VA injections, it was impossible to document if and when this had been achieved. CBV measurements using these routes of injection were therefore not reliable.

Adult rat hepatocytes cultured on an oxygen-permeable film increases the activity of albumin secretion

Primary culture of rat hepatocyte was performed in an oxygen-permeable film dish (F-dish), which would be expected to give an oxygen-rich culture condition. In the conventional culture dish in which the depth of medium was 2 mm, the oxygen tension (pO(2)) in the medium decreased from 19% (144 mmHg) to 0.3% (2.3 mmHg) within 2 hr, while the pO(2) in the F-dish maintained 8.5% (64.6 mmHg) even after 2 hr. The adverse effect of the oxygen-deficiency appeared in the albumin secretion activity of the hepatocytes and it was more remarkable in the early period of culture. The average rate of albumin secretion for the initial 48 hr was 2.0 mug ml(-1) hr(-1) or 96 mug 10(6) cells(-1) day(-1) in the F-dish. The average rate of albumin secretion for the initial 12 hr was only 0.36 mug ml(-1) hr(-1) in the conventional culture dish. The activity of ammonia elimination in the F-dish was 20-50% higher than the conventional culture dish. Three-dimensional aggregate was formed only in the F-dish. The advantage of three-dimensional aggregate for albumin secretion was not clear compared with two-dimensional monolayer.

Aneurysm ostium angle: a predictor of the need for stent as assistance for endovascular aneurysm coiling in internal carotid artery sidewall aneurysms

BACKGROUND AND PURPOSE

There is no satisfactory parameter that can predict the need for assistant devices for endovascular aneurysm coiling. Our aim was to evaluate the utility of MOA as a predictor of the need for stent-assisted coiling in ICA sidewall aneurysms.

MATERIALS AND METHODS

From a retrospective review of an internal data base, 55 consecutive ICA sidewall aneurysms were identified. Thirty-two of the aneurysms were treated by using endovascular techniques. Because 23 of the 55 aneurysms were either untreated or clipped, 3 experienced interventionalists reviewed the 3D images of these aneurysms and then made a decision as to whether stent-assisted coiling would have been required. Thirty-one of the 55 aneurysms would have required stent-assisted coiling, while 24 would not. Neck width, DNR, AR, and MOA were obtained from each aneurysm by using prototype software. These parameters were then correlated with the requirement of stent-assisted coiling.

RESULTS

MOA and neck width of aneurysms requiring stent-assisted coiling were significantly larger than those not requiring stent-assisted coiling (P < .001 and <0.001, respectively). Although the DNR and AR of aneurysms requiring stent-assisted coiling were smaller than those not requiring it, the difference was not significant (P = .22 and 0.12, respectively). ROC analysis revealed that MOA was the parameter that best correlated with the need for stent-assisted coiling. Inclusion of MOA with the rest of the parameters significantly increased the predictive performance regarding the need for stent-assisted coiling (P = .005).

CONCLUSIONS

In this small study, MOA was a useful parameter to predict the need for stent-assisted coiling in ICA sidewall aneurysms. Further prospective study of this parameter for aneurysms at multiple locations is required to determine its ultimate value.

A method for serial selective arterial catheterization and digital subtraction angiography in rodents

BACKGROUND AND PURPOSE

Imaging is a key element in the study of many rodent models of human diseases. The application of DSA has been limited in these studies in part because of a lack of a method that allows serial intra-arterial examinations to be performed during an extended period of time. It was our intent to develop and test a method for performing sequential arterial catheterizations and DSA in rats.

MATERIALS AND METHODS

Using a transfemoral approach, we subjected 12 adult male Harvey rats to 3 sequential DSA examinations during a 6- to 8-week period. At each examination, 2 selective arterial catheterizations and a DSA were performed. Animals were monitored for ill effects, and images from the 3 examinations were compared for quality and the presence of any arterial injury.

RESULTS

Ten of the 12 rats survived all 3 examinations. There were no adverse effects noted and no evidence of arterial injury from the examinations.

CONCLUSIONS

With the technique described, it is possible to perform serial arterial catheterizations and DSA in rats. This technique will be useful as an adjunct in the use of rodents for the study of human diseases.

C-arm CT measurement of cerebral blood volume in ischemic stroke: an experimental study in canines

BACKGROUND AND PURPOSE

CBV is a key parameter in distinguishing penumbra from ischemic core. The purpose of this study was to compare CBV measurements acquired with standard PCT with ones obtained with C-arm CT in a canine stroke model.

MATERIALS AND METHODS

Under an institutionally approved protocol, unilateral MCA strokes were created in 10 canines. Four hours later, DWI was used to confirm the presence of an infarct. CBV maps acquired with PCT were compared with ones acquired by using C-arm CT. Three experienced observers, blinded to the technique used for acquisition, evaluated the CBV maps.

RESULTS

An ischemic stroke was achieved in 9 of the 10 animals. Areas of reduced CBV were detected in 70%-75% of the PCT studies and in 83%-87% of the C-arm CT examinations, with false-positives in 1.7% and 3.3%, respectively. False-negatives were found in 25% of the PCT and 12.2% of the C-arm CT studies. In all studies, there was a significant difference between the absolute CBV values in normal and abnormal tissue (P < .005) and no significant difference between PCT and C-arm CT CBV values in either the normal or the abnormal parenchyma (P > .05).

CONCLUSIONS

CBV measurements made with C-arm CT compare well with ones made with PCT. While further work is required both to fully validate the technique and to define its ultimate clinical value, it appears that it offers a feasible method for assessing CBV in the angiography suite.

F1-ATPase: a highly efficient rotary ATP machine

A single molecule of F1-ATPase is by itself a rotary motor in which a central subunit, gamma, rotates against a surrounding stator cylinder made of alpha 3 beta 3 hexamer. Driven by the three beta subunits that hydrolyse ATP sequentially, the motor runs with discrete 120 degrees steps at low ATP concentrations. Over broad ranges of load and speed, the motor produces a constant torque of 40 pN.nm. The mechanical work the motor does in the 120 degrees step, or the work per ATP hydrolysed, is also constant and amounts to 80-90 pN.nm, which is close to the free energy of ATP hydrolysis. Thus this motor can work at near 100% efficiency.

Pause and rotation of F(1)-ATPase during catalysis

F(1)-ATPase is a rotary motor enzyme in which a single ATP molecule drives a 120 degrees rotation of the central gamma subunit relative to the surrounding alpha(3)beta(3) ring. Here, we show that the rotation of F(1)-ATPase spontaneously lapses into long (approximately 30 s) pauses during steady-state catalysis. The effects of ADP-Mg and mutation on the pauses, as well as kinetic comparison with bulk-phase catalysis, strongly indicate that the paused enzyme corresponds to the inactive state of F(1)-ATPase previously known as the ADP-Mg inhibited form in which F(1)-ATPase fails to release ADP-Mg from catalytic sites. The pausing position of the gamma subunit deviates from the ATP-waiting position and is most likely the recently found intermediate 90 degrees position.

Purine but not pyrimidine nucleotides support rotation of F(1)-ATPase

The binding change model for the F(1)-ATPase predicts that its rotation is intimately correlated with the changes in the affinities of the three catalytic sites for nucleotides. If so, subtle differences in the nucleotide structure may have pronounced effects on rotation. Here we show by single-molecule imaging that purine nucleotides ATP, GTP, and ITP support rotation but pyrimidine nucleotides UTP and CTP do not, suggesting that the extra ring in purine is indispensable for proper operation of this molecular motor. Although the three purine nucleotides were bound to the enzyme at different rates, all showed similar rotational characteristics: counterclockwise rotation, 120 degrees steps each driven by hydrolysis of one nucleotide molecule, occasional back steps, rotary torque of approximately 40 piconewtons (pN).nm, and mechanical work done in a step of approximately 80 pN.nm. These latter characteristics are likely to be determined by the rotational mechanism built in the protein structure, which purine nucleotides can energize. With ATP and GTP, rotation was observed even when the free energy of hydrolysis was -80 pN.nm/molecule, indicating approximately 100% efficiency. Reconstituted F(o)F(1)-ATPase actively translocated protons by hydrolyzing ATP, GTP, and ITP, but CTP and UTP were not even hydrolyzed. Isolated F(1) very slowly hydrolyzed UTP (but not CTP), suggesting possible uncoupling from rotation.

Large-scale cDNA analysis of the maternal genetic information in the egg of Halocynthia roretzi for a gene expression catalog of ascidian development

The ascidian egg is a well-known mosaic egg. In order to investigate the molecular nature of the maternal genetic information stored in the egg, we have prepared cDNAs from the mRNAs in the fertilized eggs of the ascidian, Halocynthia roretzi. The cDNAs of the ascidian embryo were sequenced, and the localization of individual mRNA was examined in staged embryos by whole-mount in situ hybridization. The data obtained were stored in the database MAGEST (http://www.genome.ad.jp/magest) and further analyzed. A total of 4240 cDNA clones were found to represent 2221 gene transcripts, including at least 934 different protein-coding sequences. The mRNA population of the egg consisted of a low prevalence, high complexity sequence set. The majority of the clones were of the rare sequence class, and of these, 42% of the clones showed significant matches with known peptides, mainly consisting of proteins with housekeeping functions such as metabolism and cell division. In addition, we found cDNAs encoding components involved in different signal transduction pathways and cDNAs encoding nucleotide-binding proteins. Large-scale analyses of the distribution of the RNA corresponding to each cDNA in the eight-cell, 110-cell and early tailbud embryos were simultaneously carried out. These analyses revealed that a small fraction of the maternal RNAs were localized in the eight-cell embryo, and that 7.9% of the clones were exclusively maternal, while 40.6% of the maternal clones showed expression in the later stages. This study provides global insights about the genes expressed during early development.

Resolution of distinct rotational substeps by submillisecond kinetic analysis of F1-ATPase

The enzyme F1-ATPase has been shown to be a rotary motor in which the central gamma-subunit rotates inside the cylinder made of alpha3beta3 subunits. At low ATP concentrations, the motor rotates in discrete 120 degrees steps, consistent with sequential ATP hydrolysis on the three beta-subunits. The mechanism of stepping is unknown. Here we show by high-speed imaging that the 120 degrees step consists of roughly 90 degrees and 30 degrees substeps, each taking only a fraction of a millisecond. ATP binding drives the 90 degrees substep, and the 30 degrees substep is probably driven by release of a hydrolysis product. The two substeps are separated by two reactions of about 1 ms, which together occupy most of the ATP hydrolysis cycle. This scheme probably applies to rotation at full speed ( approximately 130 revolutions per second at saturating ATP) down to occasional stepping at nanomolar ATP concentrations, and supports the binding-change model for ATP synthesis by reverse rotation of F1-ATPase.

Methicillin-resistant coagulase-negative staphylococci isolated from healthy horses in Japan

OBJECTIVE

To determine patterns of methicillin-resistant staphylococci isolated from apparently healthy horses.

SAMPLE POPULATION

44 horses from 8 riding clubs in Japan.

PROCEDURE

Methicill in-resistant staphylococci were isolated from the skin or nares, using a selective medium containing a beta-(symboric) lactam antibiotic, ceftizoxime. Clonality of isolates was determined by use of pulsed-field gel electrophoresis. Detection of mecA, mecl, and mecR1 genes was accomplished by use of polymerase chain reactions.

RESULT

Of the 44 horses, 13 (29.5%) yielded 15 isolates of methicillin-resistant staphylococci. The 15 isolates were identified as 6 species (Staphylococcus epidermidis, S lentus, S saprophyticus, S xylosus, S sciuri, and S haemolyticus). However, methicillin-resistant S aureus was seldom isolated. Each isolate contained the mecA gene and had a high resistance to beta-lactam antibiotics. Some isolates also were resistant to other antibiotics such as erythromycin and kanamycin.

CONCLUSIONS AND CLINICAL RELEVANCE

Methicillin-resistant coagulase-negative staphylococci that were highly resistant to various antibiotics were isolated from apparently healthy horses in Japan. These organisms must be considered a potential threat to horses and veterinarians who care for them.

Regional and strain-specific gene expression mapping in the adult mouse brain

To determine the genetic causes and molecular mechanisms responsible for neurobehavioral differences in mice, we used highly parallel gene expression profiling to detect genes that are differentially expressed between the 129SvEv and C57BL/6 mouse strains at baseline and in response to seizure. In addition, we identified genes that are differentially expressed in specific brain regions. We found that approximately 1% of expressed genes are differentially expressed between strains in at least one region of the brain and that the gene expression response to seizure is significantly different between the two inbred strains. The results lead to the identification of differences in gene expression that may account for distinct phenotypes in inbred strains and the unique functions of specific brain regions.

Stepping rotation of F1-ATPase visualized through angle-resolved single-fluorophore imaging

Orientation dependence of single-fluorophore intensity was exploited in order to videotape conformational changes in a protein machine in real time. The fluorophore Cy3 attached to the central subunit of F(1)-ATPase revealed that the subunit rotates in the molecule in discrete 120 degrees steps and that each step is driven by the hydrolysis of one ATP molecule. These results, unlike those from the previous study under a frictional load, show that the 120 degrees stepping is a genuine property of this molecular motor. The data also show that the rate of ATP binding is insensitive to the load exerted on the rotor subunit.

Hyaluronan exists in the normal stratum corneum

Hyaluronan is well known to exist as a water-sorbed macromolecule in the extracellular matrix. We here examined whether hyaluronan exists in the normal stratum corneum. High performance liquid chromatography was used to quantify hyaluronan content in the stratum corneum, epidermis (including stratum corneum), and dermis of mice, with the resulting dry weights being 22.3 +/- 2.9, 15.1 +/- 1.5, and 738.6 +/- 31.6 microg per g, respectively. Normal mouse skin was then labeled with [3H]-glucosamine in an organ culture, and accumulation of [3H]-labeled hyaluronan and its molecular mass were determined separately for the stratum corneum, epidermis, and dermis. In the stratum corneum, [3H]-labeled hyaluronan was accumulated linearly over the 3-d culture period. After the 3-d culture period, the epidermis synthesized twice the amount (expressed as dpm per mg dry weight) of [3H]-labeled hyaluronan as the dermis, whereas the stratum corneum and dermis showed nearly the same content of [3H]-labeled hyaluronan. The molecular mass of [3H]-labeled hyaluronan was highest (>1.0 x 106) in the dermis and clearly lower (<6.0 x 104) in the stratum corneum. Based on these results, we here confirm that hyaluronan is supplied from keratinocytes beneath the stratum corneum layer, and is present in the normal stratum corneum. We speculate that hyaluronan may play a role in moisturizing the stratum corneum and/or regulating its mechanical properties.

The role of the DELSEED motif of the beta subunit in rotation of F1-ATPase

F(1)-ATPase is a rotary motor protein, and ATP hydrolysis generates torque at the interface between the gamma subunit, a rotor shaft, and the alpha(3)beta(3) substructure, a stator ring. The region of conserved acidic "DELSEED" motif of the beta subunit has a contact with gamma subunit and has been assumed to be involved in torque generation. Using the thermophilic alpha(3)beta(3)gamma complex in which the corresponding sequence is DELSDED, we replaced each residue and all five acidic residues in this sequence with alanine. In addition, each of two conserved residues at the counterpart contact position of gamma subunit was also replaced. Surprisingly, all of these mutants rotated with as much torque as the wild-type. We conclude that side chains of the DELSEED motif of the beta subunit do not have a direct role in torque generation.

A rotary molecular motor that can work at near 100% efficiency

A single molecule of F1-ATPase is by itself a rotary motor in which a central gamma-subunit rotates against a surrounding cylinder made of alpha3beta3-subunits. Driven by the three betas that sequentially hydrolyse ATP, the motor rotates in discrete 120 degree steps, as demonstrated in video images of the movement of an actin filament bound, as a marker, to the central gamma-subunit. Over a broad range of load (hydrodynamic friction against the rotating actin filament) and speed, the F1 motor produces a constant torque of ca. 40 pN nm. The work done in a 120 degree step, or the work per ATP molecule, is thus ca. 80 pN nm. In cells, the free energy of ATP hydrolysis is ca. 90 pN nm per ATP molecule, suggesting that the F1 motor can work at near 100% efficiency. We confirmed in vitro that F1 indeed does ca. 80 pN nm of work under the condition where the free energy per ATP is 90 pN nm. The high efficiency may be related to the fully reversible nature of the F1 motor: the ATP synthase, of which F1 is a part, is considered to synthesize ATP from ADP and phosphate by reverse rotation of the F1 motor. Possible mechanisms of F1 rotation are discussed.

Genomic organization of the family of CNR cadherin genes in mice and humans

The cadherin-related neuronal receptor (CNR) family is localized to the synaptic junction, and their cytoplasmic domains interact with Fyn-tyrosine kinase. Here, we describe the chromosomal locations and the orthologous genomic structures of CNR family members in mice and humans. In the genomic organization, distinct exons, each of which encodes the N-terminus of a different CNR ("variable region"), are clustered in a tandem array, and these exons are spliced to a common region composed of three exons ("constant region"). We also discovered three alternative versions of the transcripts; a single variable exon connects with three different C-terminal tails, comparable to class-switching in the immunoglobulin heavy chain. Thus the CNR family in the central nervous system has similarities to the immunoglobulin and T-cell receptor genes in the immune system.

Rotation of F(1)-ATPase and the hinge residues of the beta subunit

Rotation of a motor protein, F(1)-ATPase, was demonstrated using a unique single-molecule observation system. This paper reviews what has been clarified by this system and then focuses on the role of residues at the hinge region of the beta subunit. We have visualised rotation of a single molecule of F(1)-ATPase by attaching a fluorescent actin filament to the top of the beta subunit in the immobilised F(1)-ATPase, thus settling a major controversy regarding the rotary catalysis. The rotation of the beta subunit was exclusively in one direction, as could be predicted by the crystal structure of bovine heart F(1)-ATPase. Rotation at low ATP concentrations revealed that one revolution consists of three 120 degrees steps, each fuelled by the binding of an ATP to the beta subunit. The mean work done by a 120 degrees step was approximately 80 pN nm, a value close to the free energy liberated by hydrolysis of one ATP molecule, implying nearly 100% efficiency of energy conversion. The torque is probably generated by the beta subunit, which undergoes large opening-closing domain motion upon binding of AT(D)P. We identified three hinge residues, betaHis179, betaGly180 and betaGly181, whose peptide bond dihedral angles are drastically changed during domain motion. Simultaneous substitution of these residues with alanine resulted in nearly complete loss (99%) of ATPase activity. Single or double substitution of the two Gly residues did not abolish the ATPase activity. However, reflecting the shift of the equilibrium between the open and closed forms of the beta subunit, single substitution caused changes in the propensity to generate the kinetically trapped Mg-ADP inhibited form: Gly180Ala enhanced the propensity and Gly181Ala abolished the propensity. In spite of these changes, the mean rotational torque was not changed significantly for any of the mutants.

Deletion of the myopathy loop of Dictyostelium myosin II and its impact on motor functions

One of the putative actin-binding sites of Dictyostelium myosin II is the beta-strand-turn-beta-strand structure (Ile(398)-Leu-Ala-Gly-Arg-Asp(403)-Leu-Val(405)), the "myopathy loop, " which is located at the distal end of the upper 50-kDa subdomain and next to the conserved arginine (Arg(397)), whose mutation in human cardiac myosin results in familial hypertrophic cardiomyopathy. The myopathy loop contains the TEDS residue (Asp(403)), which is a target of the heavy-chain kinase in myosin I. Moreover, the loop contains a cluster of hydrophobic residues (Ile(398), Leu(399), Leu(404), and Val(405)), whose side chains are fully exposed to the solvent. In our study, the myopathy loop was deleted from Dictyostelium myosin II to investigate its functional roles. The mutation abolished hydrophobic interactions of actin and myosin in the strong binding state during the ATPase cycle. Association of the mutant myosin and actin was maintained only through ionic interactions under these conditions. Without strong hydrophobic interactions, the mutant myosin still exhibited motor functions, although at low levels. It is likely that the observed defects resulted mainly from a loss of the cluster of hydrophobic residues, since replacement of Asp(403) or Arg(402) with alanine generated a mutant with less severe or no defects compared with those of the deletion mutant.

Tying a molecular knot with optical tweezers

Filamentous structures are abundant in cells. Relatively rigid filaments, such as microtubules and actin, serve as intracellular scaffolds that support movement and force, and their mechanical properties are crucial to their function in the cell. Some aspects of the behaviour of DNA, meanwhile, depend critically on its flexibility-for example, DNA-binding proteins can induce sharp bends in the helix. The mechanical characterization of such filaments has generally been conducted without controlling the filament shape, by the observation of thermal motions or of the response to external forces or flows. Controlled buckling of a microtubule has been reported, but the analysis of the buckled shape was complicated. Here we report the continuous control of the radius of curvature of a molecular strand by tying a knot in it, using optical tweezers to manipulate the strand's ends. We find that actin filaments break at the knot when the knot diameter falls below 0.4 microm. The pulling force at breakage is around 1 pN, two orders of magnitude smaller than the tensile stress of a straight filament. The flexural rigidity of the filament remained unchanged down to this diameter. We have also knotted a single DNA molecule, opening up the possibility of studying curvature-dependent interactions with associated proteins. We find that the knotted DNA is stronger than actin.

Direct observation of the rotation of epsilon subunit in F1-ATPase

Rotation of the epsilon subunit in F1-ATPase from thermophilic Bacillus strain PS3 (TF1) was observed under a fluorescence microscope by the method used for observation of the gamma subunit rotation (Noji, H., Yasuda, R., Yoshida, M., and Kinosita, K., Jr. (1997) Nature 386, 299-302). The alpha3 beta3 gamma epsilon complex of TF1 was fixed to a solid surface, and fluorescently labeled actin filament was attached to the epsilon subunit through biotin-streptavidin. In the presence of ATP, the filament attached to epsilon subunit rotated in a unidirection. The direction of the rotation was the same as that observed for the gamma subunit. The rotational velocity was slightly slower than the filament attached to the gamma subunit, probably due to the experimental setup used. Thus, as suggested from biochemical studies (Aggeler, R., Ogilvie, I. , and Capaldi, R. A. (1997) J. Biol. Chem. 272, 19621-19624), the epsilon subunit rotates with the gamma subunit in F1-ATPase during catalysis.

F1-ATPase is a highly efficient molecular motor that rotates with discrete 120 degree steps

A single molecule of F1-ATPase, a portion of ATP synthase, is by itself a rotary motor in which a central gamma subunit rotates against a surrounding cylinder made of alpha3beta3 subunits. Driven by three catalytic betas, each fueled with ATP, gamma makes discrete 120 degree steps, occasionally stepping backward. The work done in each step is constant over a broad range of imposed load and is close to the free energy of hydrolysis of one ATP molecule.

Diversity revealed by a novel family of cadherins expressed in neurons at a synaptic complex

In mammals, neurons are highly differentiated and play distinctive functions even in the same brain region. We found a novel cadherin-related neuronal receptor (Cnr) gene family by studying Fyn-binding activity in mouse brain. CNR1 protein is located in the synaptic junction and forms a complex with Fyn. Sequence analysis of eight Cnr products of approximately 20 genes indicates that these comprise a novel cadherin family of the cadherin superfamily. The expression patterns of each member of this novel family were grossly similar to each other but restricted to subpopulations of neurons of the same type. The diversity of the Cnr family genes suggests that there are molecular mechanisms that govern highly differentiated neural networks in the mammalian CNS.

Delayed adverse reactions to nonionic monomeric contrast-enhanced media

RATIONALE AND OBJECTIVES

A delayed adverse reaction is one occurring more than an hour after injection of contrast media. The frequency and symptoms of delayed adverse reaction to nonionic contrast media still are not well established. The purpose of the study is to clarify the frequency and symptoms of delayed adverse reactions using nonionic monomeric contrast media.

METHODS

Patients studied by computed tomography (CT) were the subject of the investigation. Delayed adverse reactions were compared between the group receiving CT without contrast injection and the group receiving contrast injection.

RESULTS

Delayed adverse reactions were noted in 293 of 2370 patients (12.4%) in the group with enhanced CT and in 93 of 907 patients (10.3%) in the group with unenhanced CT. The frequency of delayed adverse reaction to nonionic contrast media was 2.1% (12.4% - 10.3%; P = 0.094). None of the risk factors were related with the incidence of delayed adverse reaction. The most common delayed adverse reaction was a mild skin reaction, which occurred within 24 hours after injection of contrast media.

CONCLUSIONS

The frequency of delayed adverse reaction to nonionic monomeric contrast media was 2.1%; the most common reactions were itching and limited urticaria.

Rotation of the gamma subunit in F1-ATPase; evidence that ATP synthase is a rotary motor enzyme

ATP-dependent, azide-sensitive rotation of the gamma subunit relative to the alpha3beta3 hexagonal ring of ATP synthase was observed with a single molecule imaging system. Thus, ATP synthase is a rotary motor enzyme, the first ever found.

Modulation of actin filament sliding by mutations of the SH2 cysteine in Dictyostelium myosin II

The cysteine residue called SH2 in the skeletal myosin heavy chain is conserved among various species. Cys 678 in Dictyostelium myosin II is equivalent to SH2 in skeletal myosin. Using the Dictyostelium myosin II heavy chain gene, SH2 was mutated to Gly, Ala, Ser, or Thr. These mutant myosins were expressed in Dictyostelium myosin-null cells. To investigate how these mutations affect the motor functions of myosin, we examined the phenotypes of the transformed cells. We also purified the mutant myosins, and characterized them by measuring the actin-activated MgATPase activity, sliding velocity of actin filaments and force level. All of these mutant myosins complemented the myosin-specific defects of the myosin-null cells. Consistent with these observed phenotypes, all of the purified mutant myosins retained similar actin-activated MgATPase activities and force levels to those of the wild-type myosin (WT). However, the sliding velocities of actin filaments were significantly different (WT > or = Ser > Ala >> Thr > Gly). In particular, the Gly and Thr mutants exhibited a striking decrease in velocity, while the Ser mutant exhibited velocity comparable to that of the wild-type myosin. Thus, mutations of SH2 resulted in uncoupling of ATP hydrolysis and the sliding.

UVB-induced alterations in permeability barrier function: roles for epidermal hyperproliferation and thymocyte-mediated response

UV irradiation induces a variety of cutaneous responses, including disruption of epidermal permeability barrier function, the basis for which is not known. Herein, we investigated the separate roles of hyperproliferation and inflammation in the pathogenesis of UVB-induced barrier disruption. Adult hairless mice were exposed to increasing doses of UVB (1.5-7.5 MED), and transepidermal water loss (TEWL) was monitored daily for up to 7 d. The extent of TEWL increase was dependent on the UVB dose, but with all doses, the increase began after > or =48 h and peaked at 96 h, decreasing by 120 h. Epidermal [(3)H]thymidine incorporation increased at 24 h and peaked at 48 h (570%), preceding the maximal increase in TEWL. Cyclosporin A, methotrexate, 5-fluorouracil, or arabinosylcytosine significantly diminished the UVB-induced TEWL increase. Athymic nude mice also displayed a markedly diminished response to UVB, and DNA synthesis did not increased at 48 h. Transplantation of athymic mice with T-cell-enriched mixed immune cells significantly restored sensitivity to both the UVB-induced hyperproliferation and the barrier defect. Finally, although UVB exposure increased PGE2 levels in whole skin samples (2- to 3-fold within 1-3 h; p < 0.005), this increase was completely blocked by topical indomethacin, and neither topical indomethacin nor topical glucocorticoids blocked development of the barrier abnormality. These results show that (i) UVB produces delayed alteration in barrier function and (ii) both an epidermal proliferative response and thymocyte-mediated events (but not PGE2 production and nonspecific inflammation) appear to contribute to UVB-induced abrogation of the permeability barrier.

Direct observation of the rotation of F1-ATPase

Cells employ a variety of linear motors, such as myosin, kinesin and RNA polymerase, which move along and exert force on a filamentous structure. But only one rotary motor has been investigated in detail, the bacterial flagellum (a complex of about 100 protein molecules). We now show that a single molecule of F1-ATPase acts as a rotary motor, the smallest known, by direct observation of its motion. A central rotor of radius approximately 1 nm, formed by its gamma-subunit, turns in a stator barrel of radius approximately 5nm formed by three alpha- and three beta-subunits. F1-ATPase, together with the membrane-embedded proton-conducting unit F0, forms the H+-ATP synthase that reversibly couples transmembrane proton flow to ATP synthesis/hydrolysis in respiring and photosynthetic cells. It has been suggested that the gamma-subunit of F1-ATPase rotates within the alphabeta-hexamer, a conjecture supported by structural, biochemical and spectroscopic studies. We attached a fluorescent actin filament to the gamma-subunit as a marker, which enabled us to observe this motion directly. In the presence of ATP, the filament rotated for more than 100 revolutions in an anticlockwise direction when viewed from the 'membrane' side. The rotary torque produced reached more than 40 pN nm(-1) under high load.

Myxoma of the aortic valve

Myxoma of the aortic valve is exceedingly uncommon. In this article, we report a 58-year-old man with myxoma arising from the aortic valve. Aortic valve replacement was performed, and postoperative histologic examination showed myxoma of aortic valve.

Direct measurement of the torsional rigidity of single actin filaments

Flexural and torsional rigidities of actin filaments are important factors in cell motility and muscle contraction, where actin filaments serve as mechanical elements. The flexural rigidity has already been determined by directly observing the bending of individual filaments under a microscope, but measurement of the torsional rigidity has been relatively scarce and indirect, because torsion of an actin filament is difficult to visualize. This paper shows that the torsional rigidity can be measured directly by visualizing the torsional Brownian motion of a single actin filament with a novel methodology based on an optical trapping technique. Actin filaments (F-actin) were prepared by polymerizing actin monomers binding Ca2+ ion or Mg2+ ion at the high affinity site. The torsional rigidity of F-Ca(2+)-actin ((8.5(+/- 1.3)) x 10(-26) N m2) was about three times as large as that of F-Mg(2+)-actin ((2.8(+/- 0.3)) x 10(-26) N m2), whereas the flexural rigidity ((6.0(+/- 0.2)) x 10(-26) N m2) was almost independent of the kind of the bound cation. The dynamic structure of F-actin is regulated by the bound metal in an anisotropic manner. The torsional rigidities above, whether of F-Ca(2+)-actin or F-Mg(2+)-actin, are one to two orders of magnitude greater than previous experimental estimates.

Strength and lifetime of the bond between actin and skeletal muscle alpha-actinin studied with an optical trapping technique

The force required to break the bond between skeletal muscle actin and alpha-actinin (unbinding force) was measured at the level of individual molecules with an optical trapping technique. An actin filament, to the barbed-end of which was attached a gelsolin-coated polystyrene bead, was bound to alpha-actinin molecules adsorbed to a nitrocellulose-coated glass surface (approximately equal to 1 alpha-actinin molecule per 1 micron actin filament). The filament-bound bead was held by the optical trap and the force was applied to break the bond by pulling the bead. The unbinding force ranged from 1.4 to 44 pN. The average magnitude of the force was approximately equal to 18 pN. As the probability of the bond breakage has been suggested to be governed by the magnitude of the external force, the relationship was studied between the magnitude of the unbinding force and the time required to break the bond (unbinding time). The unbinding time ranged from approximately equal to 0.1 to approximately equal to 20 seconds, and tended to become shorter as the unbinding force became larger. The unbinding time seemed to be classifiable into two major groups: one group having a time value of 1 sec or less and the other having a time value ranging from several to 20 seconds. This suggests the existence of at least two classes of the actin-actinin bonds.

Primary squamous cell carcinoma of the liver: a case report

BACKGROUND

Bile cytology from percutaneous transhepatic cholangio-drainage (PTCD) is a useful procedure in case of obstructive jaundice.

CASE

Repeated cytology via PTCD from a cystically dilated duct in a 56-year-old female with a long clinical history permitted a diagnosis of squamous cell carcinoma (SCC). The smears showed excessive benign-appearing squamous cells with or without a nucleus and a few keratinized- and nonkeratinized-type SCC cells. No adenocarcinoma-derived cells were identified. No focus of SCC was detected clinically. The resected hepatic specimen disclosed a keratinized-type SCC simultaneous with benign metaplastic squamous epithelium.

CONCLUSION

This case of cytology of primary SCC of the liver seems to be the first reported. Even when showing a great number of benign-appearing squamous cells, the possibility of malignancy should not be ruled out. Repeating the cytology from PTCD is effective for a diagnosis.

Pericardial cyst in the midline position

Pericardial cysts are uncommon benign abnormalities and their incidence in mediastinal tumours is approximately 7%. The authors report the case of a 73-year-old man suffering from pericardial cyst in the midline position. The good results obtained following surgery are also reported.

[Study of washout rate in patients with chronic renal failure by dipyridamole 201Tl myocardial scintigraphy--comparison with hypertrophic cardiomyopathy]

Fourteen patients with chronic renal failure (CRF) were studied by dipyridamole 201Tl myocardial scintigraphy. In this study, patients with coronary heart disease were excluded by clinical findings. 201Tl SPECT was performed at 8 min after injection of dipyridamole (0.56 mg/kg) and at a 3-hr delayed interval, and washout rates (WR) were calculated. Because UCG showed left ventricular hypertrophy (thickness; 13 +/ 2 mm) in CRF, the WR values were compared with those of hypertrophic cardiomyopathy (HCM) (n = 9). In CRF, an average WR was 54.2 +/- 6.8% and was significantly higher than that in normal (46.2 +/- 9.1%, p < 0.05, n = 9), though WR in HCM was significantly low (26.9 +/- 11.4%, p < 0.01). Hematocrit value was 24.5 +/- 3.2% in CRF and was significantly lower than that in normal (37.8 +/- 3.6%, p < 0.001). On the other hands, hemoconcentration was observed in HCM (hematocrit; 44.6 +/- 3.6%, p < 0.001). WR in CRF, HCM and normal had significant correlation with hematocrit values (r = -0.796, p < 0.001). These results suggest that anemia or hemoconcentration may affect coronary blood flow and WR, and this should be considered when diagnosing coronary heart disease in CRF or HCM.