Splenic hemangiosarcoma in a young sprague-dawley rat

The present report describes a rare case of spontaneous hemangiosarcoma in a nine-week-old male Sprague-Dawley rat. At necropsy, multiple white nodules of various sizes were observed on and within the enlarged spleen and liver and were histopathologically determined to be composed of spindle- to oval-shaped cells that showed invasive growth without encapsulation and were arranged solidly but partially in whorls or faint alveolar patterns with vascular-like spaces containing small clefts or erythrocytes in the tumor mass. Immunohistochemical analysis revealed that most of the tumor cells were strongly positive for vimentin, von Willebrand factor (vWF) and CD34 but negative for podoplanin. In addition, electron microscopic examination revealed the presence of Weibel-Palade bodies in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as a hemangiosarcoma. The splenic masses were larger than the hepatic ones, with tumor cells mainly observed at periportal regions with tumor embolism in the liver, suggesting that primary hemangiosarcoma initially developed in the spleen before metastasizing.

Quenching electron runaway in positive high-voltage-impulse discharges in air by laser filaments

Strong hard (ε>100 keV) x rays being observed from impulse atmospheric discharges with maximal voltages from U=0.5 to 0.9 MV just before the breakdown were completely stopped with the use of femtosecond-laser-filament plasma. Runaway electrons generating such x rays and being estimated to achieve their maximal energy, ε~U, near the positive electrode disappear if a laser filament plasma is ignited perpendicularly to the runaway near the positive electrode. A preheating mechanism for formation of the electron runaway in air is proposed.

Transitional gene expression profiling in ovarian follicle during ovulation in normal-cycle rats

Evaluation of ovarian toxicity requires an understanding of the physiological changes related to the estrous cycle in the ovary. The authors investigated the transitional gene expression profile of ovulatory follicles in rats that show normal estrous cyclicity. Ovaries were collected at 10:00 and 22:00 on the proestrus day and at 10:00 on the estrus day. Ovarian follicles or early corpora lutea were isolated using laser microdissection, and extracted total RNA was analyzed using microarray technology. Clustering analysis revealed four different expression patterns: transient up- or down-regulation only at 22:00 on the proestrus day (pattern 1), up- or down-regulation only at 10:00 on the estrus day (pattern 2), continuous increase at 22:00 on the proestrus day and at 10:00 on the estrus day (pattern 3), and up- or down-regulation at 22:00 on the proestrus day and level maintenance at 10:00 on the estrus day (pattern 4). In addition, these probe sets were functionally categorized in each pattern using the Ingenuity Pathways Analysis database. These data will aid in understanding the physiology of ovulation and may be useful in assessing ovarian toxicity and its mechanism, such as in investigations of chemical-induced ovulatory impairment.

Determination of the temperature of bremsstrahlung photon generated by ultraintense laser using various thickness attenuators

We evaluate the simplified method using the Lambert-Beer law to measure the temperature of bremsstrahlung photon generated by an ultraintense laser. Analytical values are compared to the results of the Monte Carlo calculation of GEANT4 and they agreed very well on the condition of the appropriate distance between the attenuator and the detector. We performed the experiment to measure the temperature of bremsstrahlung x-ray emitted from a metal target irradiated by a Ti:sapphire laser with 76 mJ, 72 fs, 2.2 × 10(18)  W∕cm(2). For a Cu target of 30  μm thick, the photon temperature was reasonably determined to be 0.18 MeV, which is in good agreement with previous studies.

Inhibitory potency of tacrolimus ointment on skin tumor induction in a mouse model of an initiation-promotion skin tumor

Tacrolimus is a macrolide immunosuppressive agent, and tacrolimus ointment has been used as therapy for atopic dermatitis worldwide. Given that the immunosuppressive action of tacrolimus raises at least the theoretical potential for an increased risk of skin cancer, accurate assessment of the risk of developing skin cancer by tacrolimus ointment is necessary. The objective of the present study is to investigate the skin tumorigenic potential of commercially available tacrolimus ointment. We conducted a skin carcinogenicity study using an initiation-promotion (I/P) mouse model. Our study consisted of six groups (26 mice/group): sham control, absorptive ointment (AO), macrogol ointment (MO), tacrolimus ointment (TO) vehicle control, TO 0.03%, and TO 0.1%. Following a single administration of 7,12-dimethylbenz[α] anthracene (DMBA) to the dorsal skin of mice as an initiator, 12-O-tetra-decanoylphorbol-13-acetate (TPA) as a promoter and the test drugs were topically administered for 18 weeks. The incidence of skin hyperplasia in the TO 0.03% and TO 0.1% groups was reduced compared with both control groups (P < 0.05). Further, the incidence of skin neoplasia in the TO 0.03% (P < 0.05) and TO 0.1% groups (P < 0.01) was reduced in a dose-dependent manner compared with the sham control group. Tumor promotion effects on skin carcinogenesis were observed in the AO group, whereas inhibitory effects were observed in the MO group. TO 0.03% and TO 0.1% dose-dependently inhibit tumor induction in an I/P mouse model of skin tumors.

Goblet cell hyperplasia and muscular layer thickening in the small intestine of a cynomolgus monkey

We report here the interesting case of a 5-year-old male cynomolgus monkey with goblet cell hyperplasia and thickening of the muscular layer throughout the small intestine without exhibiting any clinical symptoms. Necropsy examination showed diffuse thickening of the intestinal wall from the jejunum to the ileum, with an appearance likened to a rubber tube. Histopathologically, marked thickening was observed in both the mucosal and muscular layers in the jejunum and ileum, and slight thickening was observed in the duodenum. Goblet cell hyperplasia with extension of the circular folds and villi was prominently observed. The mucosal surface was covered with a thick mucus layer containing desquamated mucosal epithelial cells, and both the inner and outer muscular layers were markedly thickened due to smooth muscle hypertrophy. Neither macroscopic nor histopathological examination identified any causative factors, such as infection, enteritis and intestinal stenosis, or obstruction that may have caused development of this lesion. Given these observations, this case may simply be considered of spontaneous goblet cell hyperplasia and muscular layer thickening in the small intestine of a cynomolgus monkey.

A Case of Spontaneous Malignant Hibernoma in a Crl:CD(SD)IGS Rat

A firm, tan, well-circumscribed mass that measured 25 × 30 × 35 mm was observed in the thoracic cavity of a 53-week-old male Crl:CD(SD) IGS rat. Histologically, the mass was encapsulated by fibrous tissue and contained fibrovascular septae. Tumor cells were compactly arranged, and most were oval to polygonal in shape with multivacuolated cytoplasm and a centrally located nucleus. In some parts of the tumor, marked cellular atypia and frequent mitoses were evident. Vacuoles in cytoplasm were positive for oil red O. The tumor cells were characterized ultrastructurally by abundant, round to oval mitochondria with transverse closely-packed cristae. Tumor cells were immunohistochemically positive for uncoupling protein 1 (UCP-1). Several thrombi and hemorrhagic or necrotic foci were also observed within the tumor mass. Vascular invasion of the tumor capsule was observed; however, invasion of surrounding tissues or metastases were not observed. Based on the pathology findings, this case was diagnosed as a malignant hibernoma.

Collaborative work on evaluation of ovarian toxicity. 12) Effects of 2- or 4-week repeated dose studies and fertility study of indomethacin in female rats

2-week and 4-week general toxicity studies of indomethacin, a nonselective inhibitor of cyclooxygenase 1 and 2, were performed using rats. A female fertility study was also conducted to compare the results to those of ovarian histopathological findings. The main purposes of the present studies are to assess whether a precise histopathological examination, taking the morphological changes the female reproductive organs undergo during each estrus phases into account, can evaluate toxicity to the ovaries, and to determine the optimal administration period for detecting ovarian toxicity. Indomethacin was administered on a daily basis to female Sprague-Dawley rats at doses of 0, 0.4, 1.3, or 4 mg/kg in the both the general toxicity studies and the female fertility study. In the general toxicity studies, unruptured follicles or luteinized cysts were observed histopathologically in the 4 mg/kg group in both the 2-week and 4-week studies. In addition, follicular cysts were found in the 4 mg/kg group in the 4-week study. Estrous cyclicity was not disturbed in both studies. There were no histopathological changes in the ovaries of the 1.3 mg/kg group in general toxicity studies. In the female fertility study, no toxic effects on female fertility parameters were detected in the 0.4 and 1.3 mg/kg group treated with indomethacin, but 8 of 10 rats in the 4 mg/kg group died or were sacrificed before completion of the dosing period. These results demonstrated that 2 weeks of indomethacin treatment is sufficient to detect unruptured follicles or luteinized cyst in the ovary. In addition, 4 weeks of dosing maybe required for induction of follicular cysts, although we could not clearly show that these histopathological changes would affect female fertility functions. These present studies suggest that a precise histopathological examination may be able to predict the effect of test articles on female reproductive functions.

Ion spectrometer composed of time-of-flight and Thomson parabola spectrometers for simultaneous characterization of laser-driven ions

An ion spectrometer, composed of a time-of-flight spectrometer (TOFS) and a Thomson parabola spectrometer (TPS), has been developed to measure energy spectra and to analyze species of laser-driven ions. Two spectrometers can be operated simultaneously, thereby facilitate to compare the independently measured data and to combine advantages of each spectrometer. Real-time and shot-to-shot characterizations have been possible with the TOFS, and species of ions can be analyzed with the TPS. The two spectrometers show very good agreement of maximum proton energy even for a single laser shot. The composite ion spectrometer can provide two complementary spectra measured by TOFS with a large solid angle and TPS with a small one for the same ion source, which are useful to estimate precise total ion number and to investigate fine structure of energy spectrum at high energy depending on the detection position and solid angle. Advantage and comparison to other online measurement system, such as the TPS equipped with microchannel plate, are discussed in terms of overlay of ion species, high-repetition rate operation, detection solid angle, and detector characteristics of imaging plate.

Abdominal cysticercosis in a cynomolgus monkey

Cysticercus tenuicollis, the larval form of Taenia hydatigena, was observed in a 5-year-old male cynomolgus monkey used in a toxicity study for a safety assessment of a pharmaceutical. The animal was born and raised in a primate colony in China. A pale yellow cyst filled with more than 100ml of pale yellow fluid was found in the abdominal cavity in the autopsy. The cyst was found attached to the greater omentum, and it was double layered. Histopathologically, the outer layer was a part of the greater omentum, and the inner layer was the bladder wall of a cysticercus with a well developed scolex. A partial sequence of mitochondrial NADH dehydrogenase subunit 1 showed a high homology to the same region of Taenia hydatigena (1.5-3.3%).

Cellular adaptations in soleus muscle during recovery after hindlimb unloading

AIM

We used a model of chronic unloading followed by reloading to examine the apoptotic responses associated with soleus muscle atrophy and subsequent recovery.

METHODS

Male Wistar rats were subjected to hindlimb unloading (HU) for 2 weeks and subsequent reloading for 0, 3, 7 and 14 days. One-half of the HU-reloaded rats were administered cyclosporine A (CsA), a calcineurin (CaN) inhibitor.

RESULTS

There was fibre atrophy (73%) and a decrease in slow type I fibre/myosin heavy chain (MyHC) composition in the soleus muscle after 2 weeks of HU. Fibre size and type I MyHC composition recovered to near the age-matched control levels by recovery day 14 in non-treated, but not in CsA-treated, rats. Myonuclear number was lower and the number of apoptotic nuclei higher in 2-week HU than control rats. These values returned to control levels after 7 and 14 days of recovery, respectively, in both HU-recovery groups. After 2 weeks of HU, the levels of heat shock proteins (Hsp) 60 and 72, mitochondrial cytochrome c oxidase subunit IV (Cox IV), and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1) proteins were lower than control. The levels of all of these proteins gradually increased to or above the control levels during cage recovery in both groups.

CONCLUSION

Our results indicate that apoptotic mechanisms are involved in the modulation of myonuclear number during chronic unloading and subsequent reloading. Furthermore, it appears that CaN is related to fibre size and phenotype adaptations, but not to apoptotic responses.

Laser ion acceleration via control of the near-critical density target

Duration-controlled amplified spontaneous emission with an intensity of 10(13) W/cm(2) is used to convert a 7.5-microm -thick polyimide foil into a near-critical plasma, in which the p -polarized, 45-fs , 10(19) -Wcm (2) laser pulse generates 3.8-MeV protons, emitted at some angle between the target normal and the laser propagation direction of 45 degrees . Particle-in-cell simulations reveal that the efficient proton acceleration is due to the generation of a quasistatic magnetic field on the target rear side with magnetic pressure inducing and sustaining a charge separation electrostatic field.

[Surgical management of acute aortic dissection complicated with cerebral malperfusion]

Although type A acute aortic dissection is considered a surgical emergency, the optimal treatment of patients with preoperative cerebral malperfusion remains controversial. From September 1994 to December 2005, 68 consecutive patients with type A aortic dissection underwent emergent surgical treatment. Eight patients showed preoperative newly-developed neurological deficits. The hospital mortality rate was 25% (2 of the 8 patients). Of the 8 patients, 1 with preoperative coma died due to severe brain injury. Another with acute myocardial infarction and left hemiparesis died due to low output syndrome in the immediate postoperative period. Three of the others had persistent left hemiplegia. One of these patients showed new paraplegia early postoperatively. The preoperative neurological deficit of the remaining 3 patients had improved in some degree. The optimal strategy should be taken individually under the accurate and prompt evaluations of hemodynamic and neurological state in such patients.

Giant electromagnetic vortex and MeV monoenergetic electrons generated by short laser pulses in underdense plasma near quarter critical density region

Very efficient generation of monoenergetic, about 1MeV , electrons from underdense plasma with its electron density close to the critical, when irradiated by an intense femtosecond laser pulse, is found via two dimensional particle-in-cell simulation. The stimulated Raman scattering of a laser pulse with frequency omega< or =2omega(pl max) gives rise to a giant electromagnetic vortex. In contrast to electron acceleration by the well-known laser pulse wake, injected plasma electrons are accelerated up to vortex ponderomotive potential forming a quite monoenergetic distribution. A relatively high charge of such an electron source makes very efficient generation of soft gamma rays with homega>300 keV .

Possible involvement of oxidative stress in piperonyl butoxide induced hepatocarcinogenesis in rats

To clarify the possible mechanism of non-genotoxic hepatocarcinogenesis induced by piperonyl butoxide (PBO), male F344 rats were administered an i.p. injection of N-diethylnitrosamine (DEN) to initiate hepatocarcinogenesis. Two weeks later, the rats were administered a PBO-containing (0, 1, or 2%) diet for 6 weeks and subjected to a two-third partial hepatectomy 1 week later. After sacrificing them on week 8, their livers were histopathologically examined and analyzed for gene expression using a microarray and real-time RT-PCR. Reactive oxygen species (ROS) products were also measured using liver microsomes. Hepatocytes exhibited centrilobular hypertrophy and increased glutathione S-transferase placental form (GST-P) positive foci formation. ROS products increased significantly in liver microsomes. In the microarray analysis, the expressions of genes related to metabolism and oxidative stress - NAD(P)H dehydrogenase, quinone 1 (Nqo1), UDP-glucuronosyltransferase (UDPGTR-2), glutathione peroxidase 2 (Gpx2), glutathione reductase (GRx) - multidrug resistance associated protein 3 (Abcc3), and solute carrier family 7 (cationic amino acid transporter, y+ system) member 5 (Slc7a5) were up-regulated in the PBO group in comparison to the 0% PBO group; this was confirmed by real-time RT-PCR. Additionally, a significant up-regulation of stress response related genes such as CYP1A1 was observed in PBO-treated groups in real-time RT-PCR. HPLC analysis revealed that the level of 8-OHdG in the 2% PBO group was significantly higher than that in the 0% PBO group. This suggests that PBO has the potential to generate ROS via metabolic pathways and induce oxidative stress, including oxidative DNA damage, resulting in the induction of hepatocellular tumors in rats.

Focusing quality of a split short laser pulse

For multiple laser pulse experiments, it is necessary to split a laser pulse. In order to split a short laser pulse without stretching the pulse width, the laser pulse should not pass through thick materials. For this reason, a pellicle beam splitter (BS) and/or a mirror with a hole are required as a BS for the short laser pulse. The focusing qualities of the laser pulse after passing through the pellicle BS and the mirror with a hole are the same as without the BS's. The laser pulse quality reflected by the BSs should be considered for the laser pulse. A pellicle BS is a thin foil, so, it is weak against vibrations. One should be careful about airflows and isolation from vibration sources. The spot size of the reflected laser pulse is consistent with the size reflected by a normal mirror. The energy loss is about 10% compared with a normal mirror. A mirror with a hole is strong against external vibrations. The reflected laser pulse has a doughnut shape. The reflected laser pulse is interfered due to the shape. In order to cleanly focus the laser pulse, the inside size of the doughnut should be smaller than a half size of the outside portion of the doughnut.

The possible mechanism of enhanced carcinogenesis induced by genotoxic carcinogens in rasH2 mice

Microarray and RT-PCR analyses were performed for the transgene and Ras-related genes in forestomach squamous cell carcinomas (SCCs) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in rasH2 mice; these results were compared with our previous molecular data of N-ethyl-N-nitrosourea-induced forestomach SCCs and urethane-induced lung adenomas in rasH2 mice. Overexpression of the transgene was detected in the DMBA-induced SCCs, suggesting that the transgene plays an important role in enhanced carcinogenesis in rasH2 mice. In addition, the mouse endogenous ras genes were up-regulated in the DMBA-induced SCCs, and are probably involved in the tumorigenesis of forestomach SCCs. Genes such as osteopontin, Cks1b, Tpm1, Reck, gelsolin, and amphiregulin that were commonly altered in these three different carcinogen-induced tumors may contribute to the development of tumors in rasH2 mice.

Foregut cyst of the oesophageal wall in a cynomolgus monkey (Macaca fascicularis)

Congenital oesophageal cysts of foregut origin are rare in animals and human beings. This report describes a case in a 4-year-old cynomolgus monkey with no clinical symptoms. The cyst, which was located within the oesophageal submucosal tissue near the mid-point of the oesophagus, was lined with pseudostratified ciliated epithelium and had a thin layer of submucosal tissue. The cyst was surrounded by a smooth muscle layer which was partly intermingled with the circular muscle layer of the oesophagus. The muscularis mucosae of the oesophagus was not shared with the cyst wall. Simple tubular glands were present, opening into the cyst lumen. No communication between the cyst lumen and the oesophagus was observed. Cartilaginous tissue, which is a diagnostic feature of bronchogenic cysts, was not identified in the cyst wall. On the basis of the histopathological features, a foregut cyst of the oesophagus was diagnosed.

Decreasing incidence of lacunar vs other types of cerebral infarction in a Japanese population

BACKGROUND

There is scant information on secular trends in the incidence and survival of ischemic stroke subtypes.

METHODS

The authors established three cohorts of Hisayama residents age > or =40 years in 1961 (1,618 subjects), 1974 (2,038 subjects), and 1988 (2,637 subjects). They followed up with each cohort for 12 years, comparing the incidence and survival rate of ischemic stroke subtypes. Morphologic examinations by autopsy or brain imaging was performed on most of the ischemic stroke cases in all cohorts.

RESULTS

The age-standardized incidence of lacunar infarction significantly declined by 59% for men and by 28% for women from the first to the second cohort. It continued to decline by 41% for men, but the decline decelerated for women between the second and third cohort. The age-standardized incidence of atherothrombotic infarction tended to decline from the first to the second cohort, whereas it was sustained between the second and third cohort for both sexes. The age-standardized incidence of cardioembolic infarction was unchanged throughout the cohorts. In these cohorts, mean blood pressure levels among hypertensive subjects and the prevalence of current smoker decreased with time, though the prevalence of hypertension remained stable. The 5-year survival rate after lacunar infarction significantly improved among the cohorts, but those of atherothrombotic and cardioembolic infarction did not.

CONCLUSIONS

These data suggest that, in the Japanese population, the incidence of lacunar infarction steadily declined for the last 40 years. The improvement of hypertension control and decreasing prevalence of smoking might be responsible for this trend.

Parous mammary glands exhibit distinct alterations in gene expression and proliferation responsiveness to carcinogenic stimuli in Lewis rats

Early full-term pregnancy affords lifetime protection against the development of breast cancer. Parity-induced protection can be reproduced in a carcinogen-induced rat mammary carcinoma model, but the molecular mechanisms of this protection against carcinogenic stimuli in rat mammary glands have not been fully characterized. To gain a better understanding of these molecular mechanisms, we used an oligonucleotide microarray to examine gene expression in parous and age-matched virgin (AMV) mammary glands of Lewis rats before and after carcinogen (N-methyl-N-nitrosourea; MNU) treatment. Parous mammary glands before MNU treatment showed up-regulation of multiple differentiation-related genes, such as whey acidic protein (Wap), casein beta (Csn2), casein gamma (Csng), lipopolysaccharide binding protein (Lbp), secreted phosphoprotein 1 (Spp1) and glycosylation-dependent cell adhesion molecule 1 (Glycam1). Also, parous mammary glands before MNU treatment exhibited down-regulation of growth-related genes such as regenerating islet-derived 3 alpha (Reg3a), mesothelin (Msln), insulin-like growth factor 2 (Igf2) and insulin-like growth factor binding protein 4 (Igfbp4). After MNU treatment, AMV mammary glands exhibited up-regulation of growth-related genes, such as Msln, cell division cycle 2 homolog A (Cdc2a), Igf2, Igfbp4, stathmin 1 (Stmn1) and homeobox, msh-like 1 (Msx1), whereas expression of these genes remained low in parous mammary glands. AMV mammary glands also exhibited marked up-regulation of Cdc2a and Stmn1 in response to MNU. After MNU treatment, the PCNA labeling index increased significantly in AMV mammary epithelial cells (13.7+/-1.1%), but remained low in parous mammary glands (3.6+/-0.4%). The response of AMV mammary glands to carcinogenic stimuli includes up-regulation of growth-related genes and increased cell proliferation. The lack of a similar response in parous mammary glands may explain parity-induced protection against mammary tumor development.

Extraskeletal osteosarcoma with cystic appearance in an aged Sprague-Dawley rat

Extraskeletal osteosarcoma, arising spontaneously from the subcutis of the left abdomen and having a cystic appearance, was found in an untreated male Sprague-Dawley rat during a carcinogenicity study. At 76 weeks of age, the tumor mass had grown to 50 x 110 x 140 mm, and the animal exhibited severe anemia related to the complication of ulceration with hemorrhage. The tumor displayed irregular ossification at the walls of a cyst-like space filled with much yellowish fluid and necrotic cellular debris. Histopathologically, the tumor consisted of sheets of large, plump osteoblast-like cells, which produced broad irregular trabeculae of osteoid and calcified osseous tissue. Since extraskeletal osteosarcoma with a cystic appearance, has not been reported in animals, except for the telangiectatic type, our case shows an extremely rare type.

Gene expression analysis of urethane-induced lung tumors in ras H2 mice

In our previous study, microarray analysis was performed on N-ethyl-N-nitrosourea (ENU)-induced forestomach tumors in transgenic mice carrying the human prototype c-Ha-ras gene (ras H2 mice). Ras-MAPK related genes, including the transgene and mouse endogenous ras genes, that are involved in enhanced carcinogenesis were up-regulated in these tumors. In the present study, ras H2 mice received five intraperitoneal injections of 1,000 mg/kg urethane at 2-day intervals. Subsequently, microarray and RT-PCR analyses for the transgene and some molecules involved in the Ras pathway were performed on the induced lung tumors. In the microarray analysis, gene expression profiles of normal lungs and adenomas showed a distinct pattern, and several genes related to the cell cycle and nucleotide metabolism were up-regulated in the adenomas. RT-PCR confirmed the overexpression of the transgene in lung tumors; however, the up-regulation of the mouse endogenous ras genes was not observed. Some genes showed a similar expression pattern in both ENU- and urethane-induced tumors. These results suggest that the overexpression of the transgene plays an important role in the carcinogenesis of both ENU- and urethane-induced tumors in ras H2 mice. The genes that showed a similar expression pattern in both tumors were considered to be the candidate genes responsible for enhanced carcinogenesis.

Ischemic brain damage after ketamine and xylazine treatment in a young laboratory monkey (Macaca fascicularis)

After a 4-year-old female laboratory cynomolgus monkey manifested neurological abnormalities, including tetanic spasm, after intramuscular injection of 20 mg/kg ketamine, we administered 2 mg/kg xylazine in an attempt to control the seizure. However, the animal continued to display opisthotonus, nystagmus, and symptomatic epilepsia. Analysis of blood chemistry revealed a dramatically increased creatine phosphokinase level. Abnormal histopathological findings included acute neuronal necrosis or glial reaction or both in the cerebral cortex, nucleus lentiformis, hippocampus, cerebellar cortex and nucleus, and medulla oblongata; severe myocardial hemorrhagic necrosis; and hepatic subcapsular hematoma. Although the mechanism of this neuronal damage has not been clarified, it may be attributable to an ischemic condition in the brain, probably due to temporal cardiac arrest or hemorrhagic change in the liver and heart, with subsequent decreased blood pressure, after ketamine and/or xylazine treatment. Because both drugs often are used as general anesthetics in veterinary medicine, attention should be paid to this rare case with neural damage.

Ten year recurrence after first ever stroke in a Japanese community: the Hisayama study

BACKGROUND

Very few population based cohort studies have focused on the long term recurrence of stroke.

OBJECTIVE

To examine 10 year cumulative recurrence rates for stroke in a Japanese cohort according to pathological type and clinical subtype of brain infarction.

METHODS

During a 32 year follow up of 1621 subjects >/=40 years of age, 410 developed first ever stroke. These were followed up prospectively for 10 years after stroke onset.

RESULTS

During follow up, 108 (26%) experienced recurrent stroke. The cumulative recurrence rates were 35.3% at five years and 51.3% at 10 years. The 10 year recurrence rates of subarachnoid haemorrhage (SAH), brain haemorrhage, and brain infarction were 70.0%, 55.6%, and 49.7%, respectively; the difference between SAH and brain infarction was significant (p = 0.004). Most recurrent episodes after SAH or brain haemorrhage happened within a year after the index stroke, whereas recurrence of brain infarction increased consistently throughout the observation period. Cardioembolic stroke had a higher recurrence rate (75.2%) than lacunar infarction (46.8%) (p = 0.049). The 10 year risk of stroke recurrence increased with age after lacunar or atherothrombotic brain infarction, but not after the other types or subtypes. After atherothrombotic brain infarction, cardioembolic stroke, or SAH, the type and subtype of most recurrent strokes were the same as for the index stroke, but recurrence after lacunar infarction or brain haemorrhage showed divergent patterns.

CONCLUSIONS

Japanese people have higher recurrence rates of stroke than other populations. Recurrence rate after a first brain infarct increases consistently through the next 10 years.

Morphological change of the micelle of poly(styrene)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) induced by binding of sodium dodecyl sulfate

Morphological change of a micelle of poly(styrene)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) (PS-PVP-PEO) polymer was induced by binding sodium dodecyl sulfate (SDS) to the PVP block in acidic aqueous solutions. The change in the size of SDS/PS-PVP-PEO complexes was detected by dynamic light scattering measurements and atomic force microscopy, and the binding of SDS was confirmed by zeta-potential measurements. When the micelle was free from SDS in acidic aqueous solutions, the hydrodynamic diameter of the micelle was 216 nm, reflecting the extended conformation of the PVP block due to the repulsion between protonated pyridine units. As the cationic PVP block was electrically neutralized with anionic SDS, the diameter was gradually reduced concomitant with the decrease in zeta-potential and finally reached 175 nm when the PVP block was completely neutralized. The decrease in the diameter shows the morphological change of the PVP block from extended to shrunken forms. Further addition of SDS did not cause the changes of the diameter nor zeta-potential. This indicates that SDS was not bound to the PS-PVP-PEO polymer after the PVP block was fully neutralized and that the hydrophobic binding of SDS to the polymer was negligible due to the low concentration of SDS.

Adhesion of Rubber to Magnesium Alloys in the Presence of Nickel Branched Alkyl Carboxylates

The authors investigated the adhesion of rubber compounds containing nickel blanched alkyl carboxylate to surface treated magnesium alloys during curing. Ni i-octylate and Ni i-stearate were used as nickel branched alkyl carboxylate. Rubbers used in the study did not adhere at all to magnesium alloys, such as AZ91, AZ31, AZ 21, and M1 washed with acetone; not even in the presence of Ni i-octylate. Among numerous treating solutions, only sodium hydroxide aqueous solution was effective for adhesion of rubber to magnesium alloys. Adhesion of rubber to magnesium alloy AZ31 treated in 0.5M- sodium hydroxide aqueous solution for 10 min at 80 °C yielded high peel strength and a 100% rubber coverage. Peel strength and a 100% rubber coverage varied with the concentration of additives, such as curing accelerators, sulfur, zinc oxide and Ni-type adhesive accelerators. Ni branched alkyl carboxylates such as Ni i-octylate and Ni i-stearate were effective for accelerating the adhesion of rubber to magnesium alloys treated in sodium hydroxide aqueous solutions during curing. The authors postulate that Ni branched alkyl carboxylate acts to yield interface bonds between magnesium alloys and rubber or Ni-S-rubber linkage.

Lack of association between lumbar disc degeneration and osteophyte formation in elderly japanese women with back pain

Our study was designed to assess the contributions of the physical and constitutional factors to osteophyte formation, disc degeneration, and bone mineral density (BMD) in lumbar vertebrae of elderly postmenopausal women. A total of 126 Japanese women with back pain, aged over 60 years, were invited to participate in the study. Then 80 subjects with a full set of data for physical examinations, radiographs, MRI, and DXA were examined. TaqI polymorphism of vitamin D receptor (VDR) gene was examined in 60 subjects. Prevalence rates of osteophytes (on radiographs) and disc degeneration (on MRI) were 61 and 68%, respectively. Body weight and BMI correlated significantly with anteroposterior (AP) and lateral (LAT) BMD (r = 0.354 for weight, r = 0.347 for BMI) and mean osteophyte area (r = 0.557 for weight, r = 0.486 for BMI), and body weight also correlated with number of discs with osteophytes. However, these did not correlate with the disc area or the number of degenerated discs. Stepwise regression analysis revealed that body weight and LAT-BMD values independently related to the osteophyte area. Disc area (r = 0.386 for AP view) and osteophyte area (r = 0.384 for AP view) significantly correlated with BMD. However, disc area and osteophyte area did not correlate with each other (r = 0.056). The proportion of degenerated discs was higher in the lower lumbar discs, but not the proportion of discs with osteophytes. Frequencies of T and t alleles of VDR did not correlate with disc degeneration, osteophyte formation, or osteoporosis. Our data showed that increases in osteophyte formation and BMD in the lumbar vertebrae are influenced by body weight and BMI, but did not correlate with disc area, which correlated inversely with BMD. Disc degeneration and osteophyte formation seem to represent two different factors that affect lumbar spine in elderly women.

Clenbuterol induces expression of multiple myosin heavy chain isoforms in rat soleus fibres

Clenbuterol, a beta2-agonist, administration results in hypertrophy of fast fibres and an increase in the fast myosin heavy chain (MHC) composition of both fast and slow muscles. The present study was designed to determine the phenotypic response at the single fibre level. Clenbuterol was added to the drinking water (30 mg L(-1)) of adult male Wistar rats for 4 weeks. Single fibres from the soleus muscle of control (10 rats; 555 fibres) and clenbuterol-treated (10 rats; 577 fibres) were dissected and their MHC isoform composition was determined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. Body, heart, and soleus weights were 9, 24, and 27% higher in clenbuterol-treated than control rats. The mean cross-sectional areas of fast and slow/fast hybrid fibres were approximately 64 and approximately 74% larger in the clenbuterol-treated than control rats, whereas the size of the slow fibres were similar in the two groups. Fibres from control soleus showed three MHC patterns: pure type I (84%), pure type IIa (4%), and type I + IIa (12%) MHC. Some fibres from clenbuterol-treated soleus showed a de novo expression of type IIx MHC resulting in the following fibre type proportions: pure type I (62%), pure type IIa (2%), type I + IIa (26%), type I + IIa + IIx (6%), and type IIa + IIx (1%). In those fibres containing multiple MHCs, there was a shift towards the faster MHC isoforms after clenbuterol treatment. These data indicate that clenbuterol results in muscle fibre hypertrophy, stimulates a de novo expression of type IIx MHC and increases the percentage of fibres containing multiple MHC isoforms in the rat soleus muscle. These phenotypic changes at the single fibre level are consistent with a clenbuterol-related shift in the functional properties of the soleus towards those observed in a faster muscle.

Molecular basis of the alteration in skin collagen metabolism in response to in vivo dexamethasone treatment: effects on the synthesis of collagen type I and III, collagenase, and tissue inhibitors of metalloproteinases

BACKGROUND

Glucocorticoids are widely used for the treatment of various diseases, despite known side-effects such as skin atrophy. Many studies have shown that the status of collagen fibres in the skin is affected by glucocorticoid treatment. However, the molecular mechanism underlying the alteration of collagen metabolism in the skin by glucocorticoid treatment remains unknown.

OBJECTIVES

To characterize the molecular mechanisms related to the deterioration of the dermis in response to glucocorticoids, the status of two major types of collagen, collagenase, and tissue inhibitors of metalloproteinases (TIMPs) in the dorsal skin of rats was studied at the protein and mRNA levels.

METHODS

Samples of rat dorsal skin were obtained after daily (1 mg kg-1) subcutaneous injections of dexamethasone (DEX) for 8 days. mRNA levels of two types of collagen and of TIMPs were measured by a lysate RNase protection assay. mRNA levels of collagenase were measured by a quantitative polymerase chain reaction. Protein levels of collagen and collagenase were measured by an immunoblot analysis.

RESULTS

Levels of type I tropocollagen and type III tropocollagen were drastically reduced in response to DEX. The effects of DEX treatment were more severe on type III than type I collagen: it also produced a significant decrease in fibril collagen of type III collagen. DEX treatment was found to decrease both active and latent forms of collagenase as well as its mRNA levels. Among TIMPs, mRNA levels of TIMP-1 and TIMP-2 were decreased in response to DEX treatment, whereas those of TIMP-3 were not affected.

CONCLUSIONS

These results suggest that DEX treatment strongly interferes with both the synthesis and degradation of type I collagen and, more drastically, type III collagen, the molecule that is known to play a major role in the initiation of wound healing. The present study may provide a molecular basis for the deterioration of skin function, impaired wound healing, and skin atrophy caused by glucocorticoid treatment.

Prognostic implications of histological features in patients with chromophobe cell renal carcinoma

OBJECTIVE

To assess the relationship between the histological features of renal chromophobe cell carcinoma (CCC) and clinical outcome in patients with renal cell carcinoma.

PATIENTS AND METHODS

From 1957 to 1996, 41 patients with CCC of the kidney (4.9% of all kidney carcinomas) were treated at our university hospitals. Of these histologically defined cases, four who died from other types of cancer and two who were lost to follow-up were excluded, leaving 35 patients in the study; the carcinoma was classified as the typical variant in 26 and the eosinophilic variant in nine. Based on the differences of the variants, the histological features affecting prognosis were analysed.

RESULTS

The overall survival rates at 1, 3, 5, 10, 15 and 20 years were 97%, 82%, 82%, 70%, 62% and 47%, respectively. The prognosis was more favourable in those with the eosinophilic than for the typical variant (there were no cancer-related deaths in the former). Of those with the typical variant, five died within 2 years of surgery; of these, three with high-stage disease had various degrees of sarcomatoid change. Conversely, two patients had a recurrence > 10 years after surgery (late recurrence). Both these patients and the others who later died from cancer had no sarcomatoid change in the tumour areas examined.

CONCLUSION

The eosinophilic variant of CCC has a better prognosis; on the contrary, during long-term surveillance, early recurrence was detected especially in those with sarcomatoid change and late recurrence only in two typical variant. These prognostic implications of the histological differences are important for understanding the outcome of renal CCC.

Gender as a prognostic factor in patients with renal cell carcinoma

OBJECTIVE

To evaluate gender as a prognostic factor in patients with renal cell carcinoma (RCC), using a retrospective review of patients with RCC stratified according to gender and analysing factors affecting prognosis.

PATIENTS AND METHODS

From January 1957 to December 1995, 768 patients with pathologically defined RCC (all of whom underwent nephrectomy) were classified as having clear cell carcinoma in 662 (follow-up in 648), papillary RCC in 43 (follow-up in 42), chromophobe cell carcinoma in 36 (follow-up in 34) and cyst-associated RCC in 27 (all followed up) according to the criteria proposed by the World Health Organization. The survival rates were compared between men and women, calculated and stratified according to the subtype of RCC.

RESULTS

There tended to be a more favourable prognosis in women than in men but the difference was not quite significant (P=0.061). Of those with clear cell carcinoma, women had a more favourable prognosis than men and the difference in survival was significant (P=0.012). No other subtype of RCC was associated with a significant difference in survival between the sexes. There was a smaller proportion of patients with stage IV and a larger proportion with stage I disease in women than in men (P<0.05). Of stage I patients, women had a more favourable prognosis than men (P<0.011). Women had better survival after recurrence than had men, the difference being significant (P=0.007).

CONCLUSION

The prognosis is significantly better in women than men with clear cell carcinoma. The factors that contribute to a favourable prognosis in women are the greater proportion of lower stage disease and better survival after recurrence.

Up-regulation of upstream stimulatory factors by protein malnutrition and its possible role in regulation of the IGF-binding protein-1 gene

Protein malnutrition drastically induces the expression of the IGF-binding protein-1 (IGFBP-1) gene. We have previously shown that the region between -77 and -112 bp upstream of the rat IGFBP-1 gene contributes to the response of this gene to amino acid limitation. In an attempt to elucidate the basis of the responsiveness of this putative amino acid response unit (AARU), we searched the nucleus of the rat liver for a trans-acting factor whose binding to AARU was dependent on protein nutrition. Liver nuclear extracts of rats fed a protein-free diet and of those fed a control diet were compared by EMSA using the AARU as probe. One of the protein-probe complexes underwent a drastic increase after dietary protein deprivation. Assays using specific antibodies and several competitor oligonucleotides led to identification of the protein composing the complex as upstream stimulatory factor-1 (USF) and USF-2. The binding site of the USF proteins in the AARU turned out to be a CACGGG sequence that was homologous to the consensus USF-binding sequence (E box; CANNTG). Further, Western blot analyses showed that a protein-free diet caused significant increases in USF-1 and USF-2 levels. Thus, elevated expression of the IGFBP-1 gene under protein malnutrition can be attributable to increased binding of USF to its promoter, which results from increased USF levels. The data suggest that the changes in these ubiquitously distributed transcription factors play an important role in the nutritional regulation of expression of mammalian genes.

[Pulmonary infarction caused by the spontaneous migration of the vena caval tumor thrombus of right renal cell carcinoma: a case report]

A 70-year-old male with right renal mass incidentally found by annual check-up using ultrasound, was referred to Department of Urology, Jikei University Affiliated Kashiwa Hospital. He was diagnosed as having right renal cell carcinoma with vena caval tumor thrombus extending above the diaphragm (T3c) preoperatively. The day before the scheduled day of operation, right pulmonary infarction caused by spontaneous migration of vena caval tumor thrombus of right renal cell carcinoma developed. Although arterial blood gas findings were poor, he only had low grade chest pain without shock. Therefore, we successfully performed right radical nephrectomy and thrombectomy of right pulmonary artery the next day. He was discharged 42 days postoperatively, but, he died from acute heart failure 9 months after the operation.

A spatial light modulator based on fused-silica plates for adaptive feedback control of intense femtosecond laser pulses

A novel spatial light modulator (SLM) made of an array of fused-silica plates was developed for the purpose of feedback control for intense femtosecond laser pulses over a wide spectral range. Dispersion compensation for 20-fs pulses from a Ti:sapphire oscillator was successfully demonstrated using the SLM with an adaptive feedback control system. The SLM was also applied to the output pulses from a Ti:sapphire amplifier for compensation of material.