Role(s) of nucleoli and phosphorylation of ribosomal protein S6 and/or HSP27 in the regulation of muscle mass

Effects of 14 days of hindlimb unloading or synergist ablation-related overloading with or without deafferentation on the fiber cross-sectional area, myonuclear number, size, and domain, the number of nucleoli in a single myonucleus, and the levels in the phosphorylation of the ribosomal protein S6 (S6) and 27-kDa heat shock protein (HSP27) were studied in rat soleus. Hypertrophy of fibers (+24%), associated with increased nucleolar number (from 1–2 to 3–5) within a myonucleus and myonuclear domain (+27%) compared with the preexperimental level, was induced by synergist ablation. Such phenomena were associated with increased levels of phosphorylated S6 (+84%) and HSP27 (+28%). Fiber atrophy (−52%), associated with decreased number (−31%) and domain size (−28%) of myonuclei and phosphorylation of S6 (−98%) and HSP27 (−63%), and with increased myonuclear size (+19%) and ubiquitination of myosin heavy chain (+33%, P > 0.05), was observed after unloading, which inhibited the mechanical load. Responses to deafferentation, which inhibited electromyogram level (−47%), were basically similar to those caused by hindlimb unloading, although the magnitudes were minor. The deafferentation-related responses were prevented and nucleolar number was even increased (+18%) by addition of synergist ablation, even though the integrated electromyogram level was still 30% less than controls. It is suggested that the load-dependent maintenance or upregulation of the nucleolar number and/or phosphorylation of S6 and HSP27 plays the important role(s) in the regulation of muscle mass. It was also indicated that such regulation was not necessarily associated with the neural activity.

Morphologic evaluation of the caudal end of the inferior petrosal sinus using 3D rotational venography

BACKGROUND AND PURPOSE

The inferior petrosal sinus (IPS) is the main transvenous access route used to examine or treat lesions involving the cavernous sinus. To carry out these procedures successfully, one must have a detailed knowledge of the anatomy of the venous system around the junction of the IPS and the internal jugular vein (IJV).

MATERIALS AND METHODS

Eighty-three sides in 63 patients (26 men, 37 women; mean, 56.5 years of age) were examined by using 3D rotational venography (3DRV).

RESULT

The drainage patterns of the IPS could be classified into the following 6 types, with emphasis on the level of IPS-IJV junction: type A, the IPS drains into the jugular bulb in 1/83 sides (1.2%); type B, the IPS drains into the IJV at the level of the extracranial opening of the hypoglossal canal in 29/83 sides (34.9%); type C, the IPS drains into the lower extracranial IJV in 31/83 sides (37.3%); type D, the IPS forms a plexus and has multiple junctions to the IJV near the jugular foramen in 5/83 sides (6.0%); type E, the IPS drains directly into the vertebral venous plexus (VVP) with no connection to the IJV in 3/83 sides (3.6%); and type F, the IPS is absent in 14/83 sides (16.9%). Each type is also characterized by the way of anastomosis with the VVP.

CONCLUSION

This classification seemed to be rational from the embryologic viewpoint, and it may be useful in establishing treatment strategies that involve endovascular manipulation via the IPS.

Accuracy of pre- and postcontrast 3D time-of-flight MR angiography in patients with acute ischemic stroke: correlation with catheter angiography

BACKGROUND AND PURPOSE

3D time-of-flight (TOF) MR angiography (MRA) is insensitive to slow flow; however, the use of MR imaging contrast agents helps to visualize slow-flow vessels and avoids overestimation of vascular occlusion. The purpose of this study was to correlate pre- and postcontrast 3D TOF MRA with the results of conventional angiography during endovascular reperfusion therapy and to determine the accuracy of postcontrast 3D TOF MRA.

MATERIALS AND METHODS

Thirteen patients who underwent endovascular reperfusion therapy for acute ischemic stroke were retrospectively analyzed. MR imaging techniques included single-slab 3D TOF MRA with and without contrast, as well as perfusion-weighted imaging. Angiography during reperfusion therapy was used as a standard of reference. Affected arteries were divided into segments either proximal or distal to the lesion, and pre- and postcontrast MRA signals were graded as absent, diminished or narrowed, or normal.

RESULTS

In 2 of 5 patients with arterial stenosis and 6 of 8 patients with complete occlusion, MRA signal intensity proximal to each lesion was absent, indicating a proximal pseudo-occlusion on precontrast MRA. Postcontrast MRA demonstrated an arterial signal intensity proximal to the stenotic or occlusive lesions in all 13 patients. Arterial signal intensity distal to the occlusion was identified on postcontrast MRA in 7 of 8 patients having complete occlusion, and the extent of occlusion on postcontrast MRA was similar to results of conventional angiography.

CONCLUSION

In this small series, postcontrast 3D TOF MRA more accurately delineated the extent of stenotic or occlusive arterial lesions than precontrast MRA.

Neuromuscular strategies for dynamic finger movements: a robotic approach

Human hand control mechanisms are extremely complex and currently there is no solution to restore full function to a paralyzed hand. The optimal solution is to use either cortical signals or desired joint angles/torques to stimulate existing muscles. One of the limiting factors in achieving this goal is a poor understanding of the relationship between the input (i.e. neural signals to muscles) and the output (i.e. joint movements) in the system (i.e. hand). There are infinitely many sets of muscle forces that generate any given set of joint torques because of redundancy and the ability to co-contract antagonist muscles. In this paper, we describe a methodology to estimate and compare biological and robotic solutions for the muscle forces for a given set of dynamic joint movements. Our preliminary results indicate that the robotic solution obtained by finding the minimum forces resembles the biological solution. This methodology may allow us to identify the neuromuscular control strategies used during dynamic finger movements.

Shaping synergistic pinching patterns with feedback distortion in a virtual rehabilitation environment

Individuals with chronic disabilities often use compensatory coordination patterns learned during the recovery phase, even after their individual muscular control returns. Although these compensatory movements limit their ability to complete tasks, these individuals are not able to relearn the correct synergistic coordination patterns because doing so would temporarily compromise task performance. Following our previous work using feedback distortion in a virtual rehabilitation environment to increase the strength and range of motion of disabled individuals, we address the use of this same feedback distortion environment to alter movement coordination patterns. In this paper, we present the methodology and preliminary results showing that (1) able-bodied individuals could be trained to use a different coordination pattern to produce pinching movements, and (2) feedback distortion can alter movements for individual fingers separately during a coordinated movement. These results indicate that our distorted virtual environment may be a powerful rehabilitation tool to convert compensatory movements into movements that utilize all muscles in the normal synergistic patterns.

Single nucleotide polymorphisms: discovery of the genetic causes of male infertility

We carried out single nucleotide polymorphism (SNP) and mutation analyses of haploid germ cell-specific genes. An analysis of 13 genes associated with male infertility in approximately 300 infertile male patients and approximately 300 male volunteers with proven fertility revealed two mutations that might produce male infertility, and three SNP/mutations associated with male infertility in 13 germ cell-specific genes. These findings strongly support the hypothesis that dysfunction of germ cell-specific genes causes idiopathic human male infertility.

Mental health service requirements in a Japanese medical centre emergency department

BACKGROUND

A significant number of emergency department (ED) patients in Japan may be affected by mental health problems leading to attempted suicide. This retrospective descriptive study aimed to explore mental health service needs in a Japanese medical centre ED.

METHODS

Data on all inpatients were collected within 24 h of admission to the ED of a medical centre in Tokyo from 1st February 2004 to the 31st of January 2005.

RESULTS

A total of 14.4% (95% CI 13.0 to 16.0) of ED visits required psychiatric services and 23.4% (95% CI 21.7 to 25.3) of inpatients had experienced psychologically traumatic events.

CONCLUSIONS

Approximately 38% (95% CI 35.8 to 39.9) of patients presenting to an ED could be affected by mental health problems.

Mechanical load-dependent regulation of satellite cell and fiber size in rat soleus muscle

The effects of mechanical unloading and reloading on the properties of rat soleus muscle fibers were investigated in male Wistar Hannover rats. Satellite cells in the fibers of control rats were distributed evenly throughout the fiber length. After 16 days of hindlimb unloading, the number of satellite cells in the central, but not the proximal or distal, region of the fiber was decreased. The number of satellite cells in the central region gradually increased during the 16-day period of reloading. The mean sarcomere length in the central region of the fibers was passively shortened during unloading due to the plantarflexed position at the ankle joint: sarcomere length was maintained at <2.1 μm, which is a critical length for tension development. Myonuclear number and domain size, fiber cross-sectional area, and the total number of mitotically active and quiescent satellite cells of whole muscle fibers were lower than control fibers after 16 days of unloading. These values then returned to control values after 16 days of reloading. These results suggest that satellite cells play an important role in the regulation of muscle fiber properties. The data also indicate that the satellite cell-related regulation of muscle fiber properties is dependent on the level of mechanical loading, which, in turn, is influenced by the mean sarcomere length. However, it is still unclear why the region-specific responses, which were obvious in satellite cells, were not induced in myonuclear number and fiber cross-sectional area.

In vivo protein transduction to the CNS

Proteins and peptides are useful research and therapeutic tools, however applications are limited because delivery to the desired location is not easily achievable. There are two hurdles in protein/peptide delivery to the brain: the blood-brain barrier and intracellular penetration. Penetration to both brain and the intracellular space can be achieved by adjusting hydrophilicity, and small molecule pharmacological agents have been successfully developed using this approach. But with proteins and peptides, it is difficult to modify the hydrophilicity without influencing biological functions. Trans-acting factor protein from the human immunodeficiency virus contains a highly conserved cationic peptide sequence necessary for transduction across the cell membrane. While trans-acting factor peptide has been used for in vitro protein transduction, its in vivo application is very limited because it is rapidly degraded by proteolysis. Polyethylenimine is a chemically synthesized small molecule cationization agent; the charge density is greater than a peptide-based cationic cluster such as trans-acting factor, and it is resistant to proteolysis in vivo. We first tested intracellular protein transduction following direct brain injection in mice using polyethylenimine-conjugated green fluorescence protein and beta-galactosidase (molecular weights 29 and 540 kDa, respectively). Polyethylenimine-conjugates penetrated to the intracellular space immediately surrounding the injection site within one hour. We further tested polyethylenimine-mediated protein transduction following intranasal administration, which bypasses the blood-brain barrier. Polyethylenimine-conjugates in pH 7.5 solution did not reach the brain, probably because the polyethylenimine-conjugates penetrated into the intracellular space where first exposed to the tissue, i.e. at the nasal mucosae. We temporarily reduced the electrostatic interaction between cationized polyethylenimine-conjugates and cellular surfaces by adjusting the pH to 4.5; solution rapidly reached the brain and penetrated to the intracellular space. This study suggests that polyethylenimine is a useful protein transduction agent in the brain in vivo, and adjusting cationic charge interaction can determine the extent of brain penetration.

Ultrasound evaluation of the fibrosis stage in chronic liver disease by the simultaneous use of low and high frequency probes

A liver biopsy is currently considered the definitive diagnostic modality for establishing the severity of hepatic fibrosis. We analysed the diagnostic sensitivity and accuracy of ultrasound (US) using both low frequency and high frequency probes as a repeatable, inexpensive, and reliable method to determine the fibrosis stage in chronic liver disease and then compared our results with the histological findings. A total of 103 patients with chronic liver disease (60 males and 43 females, average age 51 years old) who had undergone both a liver biopsy and US with 2-5 MHz frequency and 5-12 MHz frequency probes were prospectively evaluated in this study. An US scoring system using both the low frequency and high frequency probes was performed by evaluating the edge, surface and parenchymal texture of the liver. Each score was obtained by evaluating three parameters; the bluntness of the liver edge, the irregularity of the surface and the coarseness of the parenchymal texture were evaluated and then compared with the histological findings. The US scores of the liver edge (rs: 0.6668), liver surface (rs: 0.9007) and liver parenchymal texture (rs: 0.8853) correlated significantly with the fibrosis stage obtained based on the biopsy findings. The accumulated US scores of these three parameters, however, was found to be the most reliable indicator (rs: 0.9524). Patients with an accumulated score of 6.5 or more were all found to have fibrosis stage 4 in which the accuracy of our scoring system for correctly predicting cirrhosis was found to be 100% sensitive. When an accumulated US score of 3 was interpreted to indicate mild fibrosis (a fibrosis score of 0 or 1), all 42 patients with stage 0 or 1 fibrosis were found to have an accumulated US score of 3 or less (a probability of 100%) and 42 of 53 patients with a score of 3 or less were found to have stage 0 or 1 fibrosis (specificity of 79.2%). An ultrasound evaluation of the liver fibrosis stage based on the scoring system using both low and high frequency probes was found to be a reliable and effective alternative to the histological staging in chronic liver diseases.

Endovascular surgery as the first-choice treatment for ruptured cerebral aneurysms: how far has it come?

SUMMARY

One hundred and seventy patients with ruptured cerebral aneurysms were treated by coil embolization from September 1997 to December 2002. After January 2000, coil embolization was selected as the first-choice treatment for ruptured aneurysms. During this period, the authors investigated the number of aborted cases, the number of complications, and how many patients could be treated by coil embolization according to the locations of ruptured cerebral aneurysms. One hundred and ninety-five sessions were performed on 170 patients, and 13 sessions (6.7%) were aborted mainly because of the difficulty of the approach and the wide necks of the aneurysms. In four patients, although procedural perforation and haemorrhage occurred, the outcome was good or excellent. Eight poorgrade patients experienced haemorrhage after coil embolization and seven patients died. The volume embolization ratios of small and large aneurysms were 27% and 21%, and the recanalization of small and large aneurysms occurred in 9% and 38% of patients, respectively. From January 2000 to December 2002, 119 (66%) of 180 ruptured cerebral aneurysms were treated by coil embolization. According to the location of aneurysms, 89% vertebrobasilar, 87% anterior cerebral, 65% internal carotid and 24% middle cerebral artery aneurysms could be treated by coil embolization. Because the tight packing of large aneurysms was difficult, the recanalization rate of large aneurysms was high. However, the results of small aneurysms were satisfactory. Almost 90% of vertebrobasilar and anterior cerebral artery aneurysms could be treated by coil embolization.

Generation and characterization of a cold-adapted influenza A H9N2 reassortant as a live pandemic influenza virus vaccine candidate

H9N2 subtype influenza A viruses have been identified in avian species worldwide and were isolated from humans in 1999, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. Reassortant H1N1 and H3N2 human influenza A viruses with the internal genes of the influenza A/Ann Arbor/6/60 (H2N2) (AA) cold-adapted (ca) virus have proven to be attenuated and safe as live virus vaccines in humans. Using classical genetic reassortment, we generated a reassortant virus (G9/AA ca) that contains the hemagglutinin and neuraminidase genes from influenza A/chicken/Hong Kong/G9/97 (H9N2) (G9) and six internal gene segments from the AA ca virus. When administered intranasally, the reassortant virus was immunogenic and protected mice from subsequent challenge with wild-type H9N2 viruses, although it was restricted in replication in the respiratory tract of mice. The G9/AA ca virus bears properties that are desirable in a vaccine for humans and is available for clinical evaluation and use, should the need arise.

Safety evaluation in chickens of candidate human vaccines against potential pandemic strains of influenza

Two candidate formalin-inactivated vaccines, made from high-growth reassortant viruses with the HA and NA genes from avian viruses in a background of genes derived from A/Puerto Rico/8/34 (PR8), were prepared against H5N1 and H9N2 subtypes (designated as H5N1/PR8 and H9N2/PR8, respectively). These viruses bear the genotypes, antigenicity, and attenuation in mouse models that are desirable in candidate vaccines. The pathogenicity of the newly generated avian-human reassortant vaccine viruses was also evaluated in chickens. Neither H5N1/PR8 nor H9N2/PR8 were highly pathogenic for chickens. No clinical signs, gross legions, or histological lesions were observed in chickens that were administered H5N1/PR8 either intranasally (i.n.) or intravenously (i.v.), and virus was not detected in oropharyngeal or cloacal swabs. When H9N2/PR8 was administered i.n., no clinical signs, gross lesions, or histological lesions were observed and no virus was detected in cloacal swabs. However, virus was isolated at low titer from oropharyngeal swabs of all eight chickens. Although no clinical signs were observed when H9N2/PR8 was administered i.v., mild tracheitis was seen in one of two chickens. Moderate amounts of antigen were observed in tracheal respiratory epithelium, and low titers of virus were recovered from oropharyngeal and cloacal swabs of some chickens. In summary, both reassortant vaccine viruses replicated poorly in chickens. These studies suggest that these candidate vaccine viruses carry a low risk of transmission to chickens.