Evaluation of the rotational alignment of the tibial component in total knee arthroplasty: position prioritizing maximum coverage.

BACKGROUND: The standard for rotational alignment of the tibial component in total knee arthroplasty (TKA) remains unclear. Cases often require positioning of the tibial component, prioritizing adequate coverage of resected bone surface rather than alignment with the tibial rotational axis. We investigated tibial component position in TKA, prioritizing maximum coverage of resected bone surface, and evaluated the correlation with the tibial anteroposterior (AP) axis. METHODS: We analyzed preoperative computed tomography images for primary TKA in 106 cases and 157 knees, using three-dimensional planning software. Tibial component position prioritizing maximum coverage of resected bone surface was simulated, and results were compared with the AP axis. Rotational alignment angle was defined as that between a line perpendicular to the tibial AP axis and a line connecting the posterior edge of the tibial component. RESULTS: The simulated tibial component was more externally rotated by a mean 4.5° ± 4.2°. The alignment angle showed normal distribution, but variability was large, ranging from 5.1° internal rotation to 16.2° external rotation. In 138 of 157 (87.9 %) knees, the tibial component was positioned in the externally rotated position with respect to the AP axis. The tibial component was aligned within the medial one-third of the patellar tendon in 122 of 157 (77.7 %) knees. CONCLUSIONS: The tibial component aligned using coverage prioritizing was externally rotated, although large variability was observed. Rotational alignment was optimal in 79 % of cases when the tibial component was aligned with coverage prioritizing, but hyperexternal rotation was observed in patients with severe knee deformation.

Increased collagen accumulation in eggshell membrane after feeding with dietary wood charcoal powder and vinegar.

Collagen in an eggshell membrane is important for egg preservation, medical burn treatment and manufacturing of cosmetics. Because collagen in the membrane is little, it is a need to improve the accumulation in the membrane to develop these applications. Wood charcoal powder with vinegar (WCV) is a natural substance that improves poultry production. In hen fed with WCV, total collagen in the eggshell membrane increased with an increase in dietary WCV and significantly increased in the 1.0% WCV group (p < 0.05). Scanning and light microscopic images revealed that this group had thicker eggshell membranes and a fine mesh structure composed of finer and more densely distributed fibres than in the control. Eggs from WCV group showed slow Haugh unit decrease during egg storage and the decrease correlated with total collagen in eggshell membrane. In intact chicken, type I and type III collagens were found in different specific locations in the oviduct but not in the membrane. The finding that collagen accumulates in the eggshell membrane under WCV feeding suggests that feeding chicken with WCV will permit long-term storage of eggs in poultry production, and the increased volume of total collagen will facilitate its application in medicine and cosmetics.

Nuclear orphan receptor TLX induces Oct-3/4 for the survival and maintenance of adult hippocampal progenitors upon hypoxia.

Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia.

Morphological evidence of an altered process of synaptic transcytosis in adult rats exposed to ethanol.

AIMS: The effects of ethanol exposure on synaptic structure were investigated in the nucleus of solitary tract (NST) in rats, using the horse-radish peroxidase (HRP) method. METHODS: Eight-week-old experimental rats were allowed free access to a liquid diet containing ethanol for 3 weeks, while controls were given an isocaloric diet. Some of the control and experimental animals were given an injection of wheat germ agglutinin conjugated with HRP (WGA-HRP) into the vagus nerve toward the end of the treatment period. After the treatment, the neuropil region of the NST was examined under an electron microscope. RESULTS: We observed that a few terminals were characterized by deep indentation of axodendritic membranes into the post-synaptic neurons. This appeared to be similar to that commonly seen in exocrine glands. Interestingly, the indented portion often contained various sizes of vacuoles and flattened cisternae. HRP-reaction product (RP) transported to terminals was recognized easily as an electron-dense lysosomal substance when lead citrate staining was omitted. Terminals containing HRP-RP also revealed quite a similar structure with indentation of axodendritic membranes as described earlier. The results are considered to confirm that terminals forming 'apocrine-like structures' observed in the ethanol-fed animals with no injection of WGA-HRP originate from afferent fibers of the vagus nerve. CONCLUSION: The present study suggests the possibility that the alteration of the synaptic structure induced by ethanol exposure can lead to the neuronal transcytosis of materials including proteins which is different from the normal vesicular exocytosis involved in chemical synaptic transmission.

TLX activates MASH1 for induction of neuronal lineage commitment of adult hippocampal neuroprogenitors.

The orphan nuclear receptor TLX has been proposed to act as a repressor of cell cycle inhibitors to maintain the neural stem cells in an undifferentiated state, and prevents commitment into astrocyte lineages. However, little is known about the mechanism of TLX in neuronal lineage commitment and differentiation. A majority of adult rat hippocampus-derived progenitors (AHPs) cultured in the presence of FGF express a high level of TLX and a fraction of these cells also express the proneural gene MASH1. Upon FGF withdrawal, TLX rapidly decreased, while MASH1 was intensely expressed within 1h, decreasing gradually to disappear at 24h. Adenoviral transduction of TLX in AHP cells in the absence of FGF transiently increased cell proliferation, however, later resulted in neuronal differentiation by inducing MASH1, Neurogenin1, DCX, and MAP2ab. Furthermore, TLX directly targets and activates the MASH1 promoter through interaction with Sp1, recruiting co-activators whereas dismissing the co-repressor HDAC4. Conversely, silencing of TLX in AHPs decreased beta-III tubulin and DCX expression and promoted glial differentiation. Our results thus suggest that TLX not only acts as a repressor of cell cycle and glial differentiation but also activates neuronal lineage commitment in AHPs.

Comparative Analysis of Fecal Microbiota in Grasscutter (Thryonomys swinderianus) and Other Herbivorous Livestock in Ghana.

The grasscutter (also known as the greater cane rat; Thryonomys swinderianus) is a large rodent native to West Africa that is currently under domestication process for meat production. However, little is known about the physiology of this species. In the present study, aiming to provide information about gut microbiota of the grasscutter and better understand its physiology, we investigated the intestinal microbiota of grasscutters and compared it with that of other livestock (cattle, goat, rabbit, and sheep) using 16S rRNA metagenomics analysis. Similar to the other herbivorous animals, bacteria classified as Bacteroidales, Clostridiales, Ruminococcaceae, and Lachnospiraceae were abundant in the microbiome of grasscutters. However, Prevotella and Treponema bacteria, which have fiber fermentation ability, were especially abundant in grasscutters, where the relative abundance of these genera was higher than that in the other animals. The presence of these genera might confer grasscutters the ability to easily breakdown dietary fibers. Diets for grasscutters should be made from ingredients not consumed by humans to avoid competition for resources and the ability to digest fibers may allow the use of fiber-rich feed materials not used by humans. Our findings serve as reference and support future studies on changes in the gut microbiota of the grasscutter as domestication progresses in order to establish appropriate feeding methods and captivity conditions.

Characterization of neuroprogenitor cells expressing the PDGF beta-receptor within the subventricular zone of postnatal mice.

We report a considerable number of cells in the ventricular and the subventricular zones (SVZ) of newborn mice to stain positive for the PDGF beta-receptor (PDGFRB). Many of them also stained for nestin and/or GFAP but less frequently for the neuroblast marker doublecortin and for the mitotic marker Ki-67. The SVZ of mice with nestin-Cre conditional deletion of PDGFRB expressed the receptor only on blood vessels and was devoid of any morphological abnormality. PDGFRB(-/-) neurospheres showed a higher rate of apoptosis without any significant decrease in proliferation. They demonstrated reduced capacities of migration and neuronal differentiation in response to not only PDGF-BB but also bFGF. Furthermore, the PDGFR kinase inhibitor STI571 blocked the effects of bFGF in control neurosphere cultures. bFGF increased the activity of the PDGFRB promoter as well as the expression and phosphorylation of PDGFRB. These results suggest the presence of the signaling convergence between PDGF and FGF. PDGFRB is needed for survival, and the effects of bFGF in migration and neural differentiation of the cells may be potentiated by induction of PDGFRB.

Evaluation of Black Soldier Fly (Hermetia illucens) Larvae and Pre-Pupae Raised on Household Organic Waste, as Potential Ingredients for Poultry Feed.

Black soldier fly (BSF) larvae and pre-pupae could be satisfactorily raised on household organic waste and used as poultry feed, offering a potential sustainable way to recycle untapped resources of waste. The present study was conducted to determine if whole (non-defatted) BSF larvae and pre-pupae raised on experimental household waste could substitute soybean meal and oil as ingredients for laying hen diets. While no significant differences in feed intake and the egg-laying rate of hens were observed throughout the experiment, egg weight and eggshell thickness were greater in the pre-pupae-fed group than in the other groups. Moreover, although diversity of the cecal microbiota was significantly higher in the pre-pupae-fed than in the control group, no significant differences in bacterial genera known to cause food poisoning were observed when comparing the treatment groups. Nonetheless, Lactobacillus and Bifidobacterium populations were significantly lower in the treatment than in the control group. Fat content in BSF was possibly related with the changes in the cecal microbiota. Hence, since BSF fat was deficient in essential fatty acids, special attention should be paid to the fat content and its fatty acid composition in the case of regular inclusion of BSF larvae and pre-pupae oil as an ingredient in poultry diets.

Kinetics of repression by modified p53 on the PDGF beta-receptor promoter.

Herein, we show that both exogenously transfected and endogenously activated p53 repress promoter activity and expression of PDGFRB. p53 binds the proximal promoter containing the CCAAT motif as examined by EMSA and chromatin immunoprecipitation. However, gradual induction of p53 in tet-onSAOS2 cells resulted in a transient increase of the PDGFRB-promoter activity and its expression. As binding of p53 to the promoter increased, previously bound p73, DeltaNp73, c-Myc, HDAC1 and HDAC4 were dismissed from the repressed promoter, and p300 was recruited. The transient increase of the promoter activity was therefore induced by the release of the p73, Myc and HDACs, previously shown to act as repressors to this promoter. Along with further increase of p53, p300 was replaced by HDAC1 and HDAC4, resulting in decreased PDGFRB expression. For the repression, acetylation of the C-terminal lysines of p53 is important, and both acetyl-K373p53 and methyl-K370p53 became bound to the promoter. The acetyl-K373p53 was accumulated in the nucleus and colocalized with promyelocytic leukemia protein. Mitomycin treatment of MEF induced similar epigenetic modification of p53 and its binding to the promoter chromatin. Addition of a PDGFR tyrosine-kinase inhibitor to p53-inducing tet-onSAOS2 increased the number of apoptotic cells. These results suggest that p53 represses the PDGFRB promoter, facilitating the p53-induced apoptosis, whereas tumor cells with p53 mutation or a high level of DeltaNp73 or Myc could become refractory to the regulation.

Ethanol neurotoxicity and dentate gyrus development.

Maternal alcohol ingestion during pregnancy adversely affects the developing fetus, often leading to fetal alcohol syndrome (FAS). One of the most severe consequences of FAS is brain damage that is manifested as cognitive, learning, and behavioral deficits. The hippocampus plays a crucial role in such abilities; it is also known as one of the brain regions most vulnerable to ethanol-induced neurotoxicity. Our recent studies using morphometric techniques have further shown that ethanol neurotoxicity appears to affect the development of the dentate gyrus in a region-specific manner; it was found that early postnatal ethanol exposure causes a transitory deficit in the hilus volume of the dentate gyrus. It is strongly speculated that such structural modifications, even transitory ones, appear to result in developmental abnormalities in the brain circuitry and lead to the learning disabilities observed in FAS children. Based on reports on possible factors deciding ethanol neurotoxicity to the brain, we review developmental neurotoxicity to the dentate gyrus of the hippocampal formation.

Early postnatal ethanol exposure induces fluctuation in the expression of BDNF mRNA in the developing rat hippocampus.

Effects of early postnatal ethanol exposure on brain-derived neurotrophic factor (BDNF) mRNA expression in the rat hippocampus were investigated. Wistar rats were assigned to either ethanol treatment (ET) separation control (SC) or mother-reared control (MRC) groups. Ethanol exposure was achieved by a vapor inhalation method for 3 hours a day between postnatal days (PND) 1015. On PND 16, 20, 30, and 60, the expression of BDNF mRNA in the hippocampus was determined using real-time RT-PCR analysis. There was a significant age-related increase in the BDNF mRNA expression between PND 3060 in MRC animals. The BDNF mRNA expression in ET rats was increased at both PND 16 and 20 and thereafter decreased at PND 60 compared to SC animals. Such age-related fluctuation in the expression of BDNF mRNA differed from that of MRC animals. The exact functional implications, if any, of these ethanol-induced changes in BDNF mRNA expression remain unknown although it can be speculated that they may have an effect on the behaviors known to be influenced by the hippocampal formation.

The effect of prenatal X-irradiation on the developing cerebral cortex of rats. II: A quantitative assessment of glial cells in the somatosensory cortex.

The developing central nervous system is known to be highly vulnerable to X-irradiation. Although glial cells are involved in various brain functions, knowledge on the effects of X-irradiation on glial cells is limited. Therefore, the purpose of the present study was to evaluate the effects of prenatal X-irradiation on glial cells. Pregnant Wistar rats were exposed to X-irradiation at a dose of 1.0 Gy on day 15 of gestation. Their offspring were examined at 7 weeks of age. The forebrain weight of X-irradiated rats was significantly lower than that of the age-matched controls. Histological quantification with stereology of the somatosensory cortex (SC) revealed no significant difference in the numerical density of glial cells between the X-irradiated and control rats. However, the glial cells in the X-irradiated animals had significantly larger nuclear size. We had previously reported that a similar X-irradiation paradigm resulted in no significant change in the numerical density of neurons in the SC. According to the results of the present study, there were no significant differences in the glial cell-to-neuron ratios between the X-irradiated and control animals. Taken together, it is speculated that prenatal X-irradiation has an equal effects on the numerical densities of glial cells and neurons.

Changes of parvalbumin immunoreactive neurons and GFAP immunoreactive astrocytes in the rat lateral geniculate nucleus following monocular enucleation.

The expression of calcium binding proteins (CaBPs) has been linked to protection of neurons. The present study investigated the effects of monocular enucleation on the distribution of parvalbumin immunoreactive (PV-IR) neurons and glial fibrillary acidic protein immunoreactive (GFAP-IR) astrocytes in both the dorsal (dLGN) and ventral (vLGN) regions of the lateral geniculate nucleus (LGN). Our results demonstrated an increase in PV-IR neuronal density on the contralateral vLGN at 1-week post-enucleation (PE), which was maintained without significant change for 12 weeks. By contrast, PV-IR neurons in dLGN decreased significantly at all time point examined. The number of GFAP-IR astrocytes showed an initial increase from 1 to 4 weeks PE and then gradually decreased until 48 weeks in both regions of the LGN with contralateral side predominance. The present results suggest that monocular enucleation results in variable expression of PV-IR neurons and GFAP-IR astrocytes in the LGN complex, which may play an important role in neuronal degeneration and neuroplasticity of the rat visual system.

Regional differences in vulnerability of the cerebellar foliations of rats exposed to neonatal X-irradiation.

The purpose of the present study was to elucidate regional differences in the vulnerability of cerebellar foliations of rats exposed to X-irradiation. Effects of X-irradiation on foliations were examined with respect to histological changes in Purkinje cells and Bergmann glial fibers by calbindin-D28k (CB) and glial fibrillary acidic protein (GFAP) immunohistochemistry, respectively. Wistar rats were exposed to X-irradiation (1.5 Gy) on postnatal day (PND) 1. At 3 weeks of age, the cerebellum was examined. The cerebella of rats exposed to X-irradiation showed smaller and abnormal foliations compared with controls. Fewer cerebellar foliations due to fusion with neighboring folia were observed in folia I-III and VIa-VII. Moreover, the extent of such abnormalities was more severe in the latter folia. CB-immunoreactive (IR) Purkinje cells exhibited thin, short, disoriented dendrites that had invaded the granular layer or white matter. On the other hand, GFAP-IR Bergmann glial fibers had not extended their processes into the molecular layer perpendicular to the pial surface, and they appeared thin and disoriented. Accordingly, the above cerebellar abnormalities were more severe in folia I-III, VIa-VII and X than in other regions. In contrast to the histological alterations in these folia, there were no apparent qualitative differences in folia IV-V between X-irradiated and controls. These findings indicate regional difference in the vulnerability of cerebellar folia to X-irradiation. Such differences might be attributed to the cerebellar neurogenetic gradient.

Oligodendrocyte myelin glycoprotein (OMgp) in rat hippocampus is depleted by chronic ethanol consumption.

The hippocampal formation has been shown to be particularly vulnerable to the neurotoxic effects of chronic ethanol consumption. It was hypothesized that this damage was due to the disruption of the expression of neurotrophic factors and certain other proteins within the hippocampus. By using real-time reverse transcription-polymerase chain reaction (RT-PCR) techniques, this study aimed to determine whether chronic ethanol consumption could alter the mRNA expression level of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and oligodendrocyte myelin glycoprotein (OMgp) in the hippocampus. Wistar male rats received an unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole source of fluid from 10 to 29 weeks of age. Control rats had unlimited access to a liquid diet containing an isocaloric amount of sucrose. We found that chronic ethanol consumption did not cause significant changes in the levels of mRNA for BDNF and GDNF. However, OMgp mRNA showed a significant deficit in ethanol-treated animals. It is suggested that this deficit may be related to the demyelination that is commonly observed in human alcoholics and that this may contribute to the functional and cognitive deficits.

Age-related changes in growth hormone-immunoreactive cells in the anterior pituitary gland of Jcl: Wistar-TgN (ARGHGEN) 1Nts rats (Mini rats).

Rats of the Jcl: Wistar-TgN (ARGHGEN) 1Nts strain (Mini rats) are transgenic animals carrying an antisense RNA transgene for rat growth hormone (GH); they show poor somatic growth and a low blood GH level compared to age-matched wild-type Wistar (non-Mini) rats. The purpose of the present study was to investigate age-related changes in growth hormone-immunoreactive (GH-IR) cells in the anterior pituitary gland (AP) of Mini rats at four, six, and eight weeks of age. The body weight and size of the GH-IR cells of Mini rats was significantly lower than that of non-Mini rats at six and eight weeks of age; however, this difference was not observed at four weeks of age. The AP volume and the number of GH-IR cells in Mini rats were significantly smaller than those of the age-matched non-Mini rats at the three ages. These results suggest that the abnormal development of GH-IR cells in the AP induced by the GH antisense RNA transgene is responsible for the poor somatic growth and the low blood GH levels in Mini rats.

Effects of chronic ethanol administration on the expression levels of neurotrophic factors in the rat hippocampus.

Chronic ethanol consumption has adverse effects on the central nervous system. Hippocampus is one of the target sites of ethanol neurotoxicity. Hippocampal damage is known to result in impairment of learning and memory. This study was aimed to determine whether chronic ethanol consumption could alter the expression levels of brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) mRNAs in the hippocampus. Male Wistar rats were given unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole fluid source for 19 weeks beginning at 10 weeks of age. The expression levels of BDNF and GDNF mRNAs in the hippocampus were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. The present study revealed that chronic ethanol consumption did not result in significant changes in the expression levels of BDNF and GDNF mRNAs. Our present results showed no significant alteration in the expression of these neurotrophic factors; these results will lead to further studies to examine the possible alterations in the gene expression of various neurotrophins that are related to hippocampal functions including learning and memory.

Application of the physical disector to the central nervous system: estimation of the total number of neurons in subdivisions of the rat hippocampus.

Stereology is a group of mathematical and statistical methods that allows the extrapolation of three-dimensional structural information from two-dimensional sections (or slices). This allows researchers to derive important quantitative structural information, such as the volume, surface area or numbers of particular particles (e.g. cells) within defined regional boundaries. The need for such quantitative information in biology is of particular importance when evaluating the influence of various experimental treatments on specific organs, tissues and cells in the body. Knowledge of such changes has given important insights into the neural substrates that may be responsible for the functional and behavioral consequences of a disparate range of experimental treatments. Here, we describe some of these methods as applied to quantifying the total numbers of cells in defined regions of the hippocampal formation. The methods used for this evaluation were, first, the Cavalieri principle, which was used to determine the volumes of the various subdivisions of the rat hippocampus, and, second, the 'physical disector' method, which was used to estimate the numerical density of neurons within each subdivision. Once these values were derived, it was but a simple task to multiply them together to obtain estimates for the total numbers of cells in the given hippocampal region. We found that 16-and 30-day-old normal male rats had 176 800 and 152 700 pyramidal cells in the CA1 region, respectively. This decrease in the neuronal number was statistically significant. However, in the CA2 + CA3 region, there were approximately 169 300 and 149 600 pyramidal cells in 16- and 30-day-old normal male rats, respectively, which was not significantly different. In the dentate gyrus, there were approximately 36 700 neurons in the hilus region and 483 000 granule cells in the granule cell layer, irrespective of the age of the rats. There were no significant differences between these estimates of hilus neurons and granule cells.

Effects of monocular enucleation on calbindin-D 28k and c-Fos expression in the lateral geniculate nucleus in rats.

The present study was undertaken to evaluate the effects of monocular enucleation on the calbindin-D 28k (CB) and c-Fos immunoreactive (IR) neurons in the lateral geniculate nucleus (LGN) complex of adult rats. The enucleation resulted in neuronal degeneration and decrease of neurons in the LGN complex. Our study demonstrated a decrease of CB-IR neuronal density on the contralateral side of the ventral (vLGN) and dorsal LGN (dLGN) until 12 weeks post-enucleation (PE). On the ipsilateral side, CB-IR neuronal density in the dLGN and vLGN showed significant and continuous decrease until 48 and 12 weeks PE, respectively. In an additional experiment, c-Fos-IR neurons were increased at 2 days PE in the vLGN with ipsilateral predominance. At 7 days, c-Fos-IR neurons on the ipsilateral vLGN were still higher than those of pre-enucleated rats. The present results suggest that monocular enucleation affects the expression of the CB and c-Fos in the LGN complex. It is indicated that these may play an important role in the neuronal degeneration and neuroplasticity of the subvisual system in rats.

Excessive testosterone treatment and castration induce reactive astrocytes and fos immunoreactivity in suprachiasmatic nucleus of mice.

The suprachiasmatic nucleus (SCN) has long been recognized as the central mammalian circadian pacemaker that controls behavioral and physiological processes. The role of the SCN in circadian rhythms has been the subject of a wide range of physiological and behavioral studies, although the influence of homeostasis rhythms (such as fluctuating hormone levels) on the SCN of the hypothalamus is not entirely clear. The present study was undertaken to examine the morphological interactions between astroglial and neuronal elements in the SCN of mice after either a short-term excessive testosterone treatment (ETT) or castration, using glial fibrillary acidic protein (GFAP), and immediate early gene c-fos as well as calbindin-D28k (CB) immunohistochemistry. Both ETT and castration resulted in a significant increase in the accumulation of reactive astrocytes and Fos-imunoreactivity (IR), especially in the dorsomedial (DM) sub-region of the SCN. However, CB-IR neurons in the examined brain regions showed little change. These findings indicate that the DM sub-region of the SCN may be a possible center of hormonal regulation via a hypothalamic neuroendocrine circuit, and that a non-photic stimuli mechanism might play a role in circadian rhythm regulation.