Heavy thinning in hinoki plantations in Shikoku (southwestern Japan) has limited effects on recruitment of seedlings of other tree species

Heavy thinning may provide a feasible means to convert single-species coniferous plantations to broadleaved or mixed forests. To assess this possibility, we monitored tree seedling dynamics of other tree species, the understory microenvironment, and seed availability following heavy thinning (50 % by volume) in two hinoki (Chamaecyparis obtusa) plantations in Shikoku, southwestern Japan. Conventional (35 % by volume) and row thinning (50 % by volume) treatments were also applied at one of the sites. Diffuse transmittance in the understory dramatically increased after all thinning treatments then rapidly decreased, except after row thinning. Heavy thinning accelerated recruitment of small seedlings (with stems <30 cm high) at one of the sites. However, the densities of these seedlings declined sharply, and increases in the densities of larger seedlings recorded in subsequent surveys were very small. Furthermore, at the other site, recruitment of small seedlings under heavy thinning was equivalent to that under conventional thinning and lower than that under row thinning. Abundant species in the recruited seedlings were pioneer or subcanopy species found in the soil seed bank. Low seed rain density at both sites appeared to be responsible for the poor recruitment of canopy tree species. Our results suggest that heavy thinning had limited effects on the seedling recruitment of other tree species in these hinoki plantations due to insufficient seed rain and rapid canopy closure.     

The histopathogenesis of paralytic rabies in six-week-old C57BL/6J mice following inoculation of the CVS-11 strain into the right triceps surae muscle

A fatal encephalomyelitis was developed after intracerebral and hind limb inoculation of in 6-week-old C57BL/6J mice by the inoculation of fixed rabies virus (CVS-11 strain), intracerebrally and into hind. After the intracerebral inoculation, virus antigens were detected in the cerebral cortex and hippocampus at 2 days postinoculation (PI), and later spread centrifugally to thalamus, brain stem, cerebellum, spinal cord and spinal ganglia. At 4 days PI, severe apoptosis and DNA fragmentation were observed in the hippocampus and cerebral cortex. All mice infected intracerebrally were dead without limb paralysis at from 10 to 11 days PI. In contrast, mice infected with virus intramuscularly were persistently observed virus antigens in the myocytes at the site of inoculation from 2 days PI. At 4 days PI, the antigens were demonstrated in the spinal dorsal root ganglia, spinal cord and muscle spindles without their detection in the cerebrum and hippocampus. There were no apoptosis in the spinal cord and dorsal root ganglia, however hind limb paralysis was found in all infected mice. Hind limb paralysis was progressed to quadriparalysis, and mice were dead from 11 to 13 days PI. From 4 days PI, necrosis of neuron was observed in the the spinal and dorsal ganglia with infiltration of lymphocyte. This study suggested that the necrosis of spinal neurons was more important to cause the paralysis of hind limb rather than the severe cerebral infection and apoptosis in C57BL/6J mice infected with CVS-11 strain. The virus primarily replicated in the muscles was ascended the spinal cord via afferent fibers and retrogradely invaded the cerebrum, and with subsequent spread to muscle spindles.     

Identification of small molecule activators of cryptochrome

Impairment of the circadian clock has been associated with numerous disorders, including metabolic disease. Although small molecules that modulate clock function might offer therapeutic approaches to such diseases, only a few compounds have been identified that selectively target core clock proteins. From an unbiased cell-based circadian phenotypic screen, we identified KL001, a small molecule that specifically interacts with cryptochrome (CRY). KL001 prevented ubiquitin-dependent degradation of CRY, resulting in lengthening of the circadian period. In combination with mathematical modeling, our studies using KL001 revealed that CRY1 and CRY2 share a similar functional role in the period regulation. Furthermore, KL001-mediated CRY stabilization inhibited glucagon-induced gluconeogenesis in primary hepatocytes. KL001 thus provides a tool to study the regulation of CRY-dependent physiology and aid development of clock-based therapeutics of diabetes.     

Fascin‐1 expression in canine cutaneous and oral melanocytic tumours

Fascin‐1 expression was examined in 9 cutaneous melanocytomas and 47 oral melanomas. The cases were scored on the basis of extent and intensity of staining, and combined scores were calculated. Fascin‐1 expression was observed in 5/9 (56%) melanocytomas and 46/47 (98%) melanomas. The combined score for fascin‐1 was significantly greater in stage III/IV melanomas than in stage I/II melanomas (P < 0.05). In addition, strong fascin‐1 staining was associated with a significantly shortened survival time (P < 0.05). The results of this study suggest that fascin‐1 overexpression correlates with the malignancy of canine melanoma and has the potential to be a new immunohistochemical marker to predict the clinical course of canine melanoma. In addition, targeted therapy for fascin‐1 may represent a new strategy for the treatment of canine melanoma.     

Leydig cell hyperplasia in an ENU-induced mutant mouse with germ cell depletion

Repro22 is an N-ethyl-N-nitrosourea (ENU)-induced mutation in mice showing depletion of both male and female germ cells. In the present study, we investigated the male phenotypes of the mutant mouse at the adult stage. The repro22/repro22 homozygous mice showed reduced body weights as well as markedly reduced testis weights. Histological examination of the testes at 4 and 10 months of age showed no germ cells in the seminiferous tubules of the affected testis while a number of Sertoli cells were observed in the tubules. In addition to the germ cell depletion, the testes of the affected mouse contained expanded intertubular spaces that were filled by Leydig cell-like interstitial cells. These interstitial cells were confirmed to be Leydig cells by immunohistochmical staining using anti-3beta-HSD antibody. The estimated number of Leydig cells in the affected testes at 10 months of age increased approximately 2 fold compared with those of normal testes. Furthermore, the plasma testosterone levels of the affected mice at 10 months of age were significantly higher than those of the normal mice. These findings indicated that the repro22/repro22 mouse developed hyperplasia of Leydig cells that was presumably caused by the absence of germ cells in the seminiferous tubules.     

Renal microangiography and correlated histopathological observation of cows with nephropathy.

Seven Holstein-Friesian cows showing chronic nephropathy were studied by renal microangiography and its correlated histopathology. In cases of pyelonephritis associated with severe pathological lesions such as thickening of arterial walls, narrowing of the arterial and arteriolar lumen, and interstitial inflammation and abscess formation, patchy loss of the peritubular capillary plexus from the cortex to the medulla was clearly demonstrated by microangiography. Interlobular arteries were tortuous and attenuated or truncated. Opacification in the vasa rectae and interstitial capillaries was increased. Extensive non-perfused regions could be detected in the cortex. In cases of mild interstitial nephritis and moderate pyelonephritis, microangiography showed focal changes in the renal vasculature. Microangiography is thus shown to clearly demonstrate changes in the renal vasculature corresponding to the severity of the histopathological lesions.     

Identification of an Avirulence Gene in the Fungus Magnaporthe grisea Corresponding to a Resistance Gene at the Pik Locus

ABSTRACT A rice isolate of Magnaporthe grisea collected from China was avirulent on rice cvs. Hattan 3 and 13 other Japanese rice cultivars. The rice cv. Hattan 3 is susceptible to almost all Japanese blast fungus isolates from rice. The genetic basis of avirulence in the Chinese isolate on Japanese rice cultivars was studied using a cross between the Chinese isolate and a laboratory isolate. The segregation of avirulence or virulence was studied in 185 progeny from the cross, and monogenic control was demonstrated for avirulence to the 14 rice cultivars. The resistance gene that corresponds to the avirulence gene (Avr-Hattan 3) is thought to be located at the Pik locus. Resistance and susceptibility in response to the Chinese isolate in F(3) lines of a cross of resistant and susceptible rice cultivars were very similar to the Pik tester isolate, Ken54-20. Random amplified polymorphic DNA markers and restriction fragment length polymorphism markers from genetic maps of the fungus were used to construct a partial genetic map of Avr-Hattan 3. We obtained several flanking markers and one co-segregated marker of Avr-Hattan 3 in the 144 mapping population.     

Plasma concentrations of inhibin A in cattle with follicular cysts: relationships with turnover of follicular waves and plasma levels of gonadotropins and steroid hormones

We investigated the profiles of circulating levels of inhibin A and total inhibin in beef cows with follicular cysts in relation to the patterns of follicular development and circulating gonadotropins and steroid hormones. Turnover of follicular waves was monitored in five cows every 2 days for 70 days from 10 days after detection of estrus without ovulation. The mean interwave intervals were 19.6 ± 1.0 days (n = 18 waves with cysts from the five cows). Circulating levels of inhibin A were approximately 170 pg/ml before emergence of follicular waves with cysts and increased (P < 0.05) concomitantly with follicle emergence. High concentrations of inhibin A (greater than 300 pg/ml) were noted for 7 days during the growth phase of cystic follicles, but inhibin A levels decreased gradually when development of the cysts reached a plateau. This profile of inhibin A was similar to those of total inhibin and estradiol, but was inversely related to the changes in plasma FSH concentrations. LH pulse frequency and mean concentrations of LH in cows with cysts were higher than those observed in the luteal phase of normal cyclic cows. These results indicate that the capacity to secrete inhibin, as well as estradiol, is maintained in cystic follicles, the growth of which is extended by LH secretion at levels greater than those seen in the normal luteal phase. Inhibin A plays an important role in the extension of interwave intervals by suppressing recruitment of a new cohort of follicles.     

Retrospective analysis of the efficacy of controlled internal drug release in follicular cysts in an embryo donor beef herd

We investigated the efficacy of a controlled internal drug release (CIDR) device in the reproductive management of an embryo donor beef herd. Superovulation of embryo donors was routinely induced by a combination of FSH and prostaglandin F(2)alpha analogue (PGF(2)alpha) at intervals of a few months, and after embryo recovery estrus of the donors was synchronized with PGF2(2)alpha. Between 1996 and 1998, approximately 20% of donors were diagnosed as having follicular cysts every year. Twenty-eight cases of follicular cysts recorded between 1997 and 1998 were treated with a CIDR device for 14 days to evaluate the efficacy of CIDR in resolving follicular cysts in donor herds. Initial recovery was defined as the occurrence of ovulation with estrous behavior and subsequent formation of a corpus luteum after removal of the CIDR. Initial recovery was recognized in all cases (n=28). Follicular cysts did not recur after repeated embryo recovery in 64% of the initially recovered donors, but in 36% of affected donors cysts recurred after the next embryo recovery. Subsequently, with a CIDR device instead of PGF(2)alpha, we synchronized estrus after embryo recovery in the same herd from 1999 to 2000, to investigate the ability of CIDR to prevent the initiation of follicular cysts. Of the donors used between 1999 and 2000, approximately 30% had a history of follicular cysts. Use of CIDR for estrous synchronization after embryo recovery lowered the incidence of follicular cysts to 3% in 1999 and 0% in 2000. Treatment with CIDR proved effective at resolving follicular cysts in the embryo donor beef herd and enabled re-use of donors affected with follicular cysts. CIDR is also likely to be efficacious in lowering the occurrence of follicular cysts in donor herds when it is used for estrous synchronization after embryo recovery.     

Itokawa dust particles: a direct link between S-type asteroids and ordinary chondrites

The Hayabusa spacecraft successfully recovered dust particles from the surface of near-Earth asteroid 25143 Itokawa. Synchrotron-radiation x-ray diffraction and transmission and scanning electron microscope analyses indicate that the mineralogy and mineral chemistry of the Itokawa dust particles are identical to those of thermally metamorphosed LL chondrites, consistent with spectroscopic observations made from Earth and by the Hayabusa spacecraft. Our results directly demonstrate that ordinary chondrites, the most abundant meteorites found on Earth, come from S-type asteroids. Mineral chemistry indicates that the majority of regolith surface particles suffered long-term thermal annealing and subsequent impact shock, suggesting that Itokawa is an asteroid made of reassembled pieces of the interior portions of a once larger asteroid.