JADE1 is dispensable for the brain development in mice

In mammalian brain development, WNT signaling balances proliferation and differentiation of neural progenitor cells, and is essential for the maintenance of regular brain development. JADE1 is a candidate transcription co-factor essential for DNA replication, cell division, and cell cycle regulation. In 293T cells, JADE1 is stabilized by von Hippel-Lindau protein pVHL, promotes the β-catenin ubiquitination and thus blunts canonical WNT signaling. Furthermore, JADE1 inhibits β-catenin-induced ectopic axis formation in Xenopus embryos. However, JADE1's role in mammalian brain development remains unknown. Here, we generated a new Jade1 knockout mouse line using CRISPR-Cas9 technology. We found that JADE1 null resulted in decreased survival rate, reduced body weight and brain weight in mice. However, histological analysis revealed a normal brain development. Furthermore, Jade1 null neural progenitor cells proliferated normally in vivo and in vitro. RNA-seq analysis further showed that JADE1 loss did not affect the cerebral cortex gene expression. Our findings indicate that JADE1 is dispensable for developing the cerebral cortex in mice.

Transepithelial Secretion of Mucosal IgM Mediated by Polymeric Immunoglobulin Receptor of Flounder (Paralichthys olivaceus): In-Vivo and In-Vitro Evidence

Secretory immunoglobulin (SIg) is crucial for mucosal surface defenses, but the transepithelial secretion of SIg mediated by polymeric immunoglobulin receptor (pIgR) is not clarified in fish. We previously found that flounder (Paralichthys olivaceus) pIgR (fpIgR) and secretory IgM (SIgM) increased in gut mucus post-vaccination. Here, the fpIgR-positive signal was mainly observed in the intestinal epithelium, whereas the IgM-positive signal was mainly distributed in the lamina propria, before immunization. IgM signals increased in the lamina propria and then in the epithelium after immunization with inactivated Vibrio anguillarum, and co-localization between IgM and fpIgR in the epithelium was determined, while the presence of EdU⁺IgM⁺ cells in the lamina propria identified the proliferative B cells, revealing that the secretion and transepithelial transport of SIgM locally occurred in the gut of flounder. Subsequently, we established an in-vitro model of transfected MDCK cells that stably expressed the fpIgR. After a recombinant eukaryotic expression plasmid (pCIneoEGFP-fpIgR) was constructed and transfected into MDCK cells, stable expression of the fpIgR in transfected MDCK-fpIgR cells was confirmed, and the tightness and integrity of the polarized cell monolayers grown on Transwells were evaluated. Afterward, the serum IgM of flounder was purified as a binding ligand and placed in the lower compartment of Transwells. An ~800-kDa protein band in the upper compartment was shown to be IgM- and fpIgR-positive, and IgM-positive fluorescence was seen in MDCK-fpIgR cells but not in MDCK-mock cells. Hence, the fpIgR helped polymeric IgM to pass across MDCK-fpIgR cells via transcytosis in a basolateral-to-apical fashion. These new findings provide a better understanding of the pathways shaping mucosal IgM responses and the local mucosal immune mechanisms in teleosts.

[PD-1 is associated with CD8(+)T lymphocyte dysfunction in patients with acute and chronic liver failure]

Objective: To explore whether peripheral blood CD8(+)T lymphocyte dysfunction is correlated with the programmed death receptor-1 (PD-1) expression in patients with acute-on-chronic liver failure (HBV-ACLF). Methods: Peripheral blood mononuclear cells (PBMC) were collected from patients with HBV-ACLF and healthy controls. CD8(+)T lymphocytes number and PD-1 expression condition in CD8(+)T lymphocytes were detected by flow cytometry. CD8(+)T lymphocytes isolated from peripheral blood of HBV-ACLF patients were further cultured in vitro. One group was added with PD-L1-IgG fusion protein (ACLF+PD-1 group), and the other group was added with IgG fusion protein (ACLF group). Proliferation ability (ki67), cell viability (CD69), and secretion ability of effector cytokines (IL-2, IFN-γ, TNF-α) were analyzed. Results: 30 cases with HBV-ACLF and healthy controls were enrolled. CD8(+)T lymphocytes absolute number was significantly lower in the peripheral blood of patients with ACLF group (333.88 ± 147.74)/μl than healthy controls (872.50 ± 206.64)/μl (P < 0.001). PD-1 expression in peripheral blood CD8(+)T lymphocytes were significantly increased in ACLF group (13.33% ± 2.52%), (P = 0.027) than healthy controls (7.02% ± 2.12%). In in vitro culture, compared with healthy controls, the peripheral blood CD8(+)T lymphocytes cell viability (CD69), proliferation ability (ki67) (all P ​​< 0.001), and the level of cytokine production (IL-2, IFN-γ, TNF-α) (all P < 0.05) were equally weakened in patients with ACLF group. Compared with ACLF group, CD8(+)T cell viability (CD69), proliferation ability (KI67) (all P < 0.05), and the level of cytokine production were weakened in ACLF+PD-1 group (all P < 0.05). Conclusion: HBV-ACLF patients have CD8(+)T lymphocyte dysfunction. Therefore, PD-1 may have correlation in the regulation of CD8(+)T lymphocyte dysfunction in ACLF patients.

[Transcranial sonographic characteristics of Parkinson's disease with symptoms of restless legs syndrome]

Objective: To evaluate the transcranial sonographic characteristics in patients with Parkinson's disease (PD) with symptoms of restless legs syndrome (RLS). Methods: Patients with diagnosis of definite PD from the Second Affiliated Hospital of Soochow University and 3 other participating hospitals between September 2018 and December 2019 were consecutively enrolled. Concurrent RLS symptoms were determined using Non-motor Symptoms Questionnaire. Transcranial sonography (TCS) and clinical assessments were performed during the same time and the related variables were compared between the two groups using t-test, non-parametric test, Chi-square test and Spearman correlation analysis, respectively. Results: Among 349 patients with PD, the prevalence of RLS symptoms was 22.6%. Compared to patients without RLS symptoms, those with RLS had longer disease duration (43.0 (24.0, 91.0) months vs 37.0 (20.0, 60.0) months, P<0.05) and higher Hoehn-Yahr stage (2.5 (2.0, 3.0) vs 2.0 (1.5, 2.5), P<0.01).TCS revealed that patients with RLS symptoms were more likely to have abnormality in the raphe nucleus (21.50% vs 7.78%, χ²=15.9, P<0.001) and increased third ventricle width ((6.22±1.97) mm vs (5.16±1.90) mm, P<0.001). No significant differences were found regarding parameters of substantia nigra. Conclusions: Concurrent RLS symptoms are common in PD patients. Abnormal echogenicity of raphe nucleus and increased third ventricle width could be characteristics of TCS in PD patients with RLS symptoms.

Mortality under early access to antiretroviral therapy vs. Eswatini's national standard of care: the MaxART clustered randomized stepped-wedge trial

OBJECTIVES

Current WHO guidelines recommend the treatment of all HIV-infected individuals with antiretroviral therapy (ART) to improve survival and quality of life, and decrease infection of others. MaxART is the first implementation trial of this strategy embedded within a government-managed health system, and assesses mortality as a secondary outcome. Because primary findings strongly supported scale-up of the 'treat all' strategy (hereafter Treat All), this analysis examines mortality as an additional indicator of its impact.

METHODS

MaxART was conducted in 14 Eswatinian health clinics through a clinic-based stepped-wedge design, by transitioning clinics from then-national standard of care (SoC) to the Treat All intervention. All-cause, disease-related, and HIV-related mortality were analysed using the Cox proportional hazards model, censoring SoC participants at clinic transition. Median follow-up time among study participants was 292 days. There were 36/2034 deaths in SoC (1.77%) and 49/1371 deaths in Treat All (3.57%).

RESULTS

Between September 2014 and August 2017, 3405 participants were enrolled. In SoC and Treat All interventions, respectively, the multivariable-adjusted 12-month all-cause mortality rates were 1.42% [95% confidence interval (CI): 0.66-2.17] and 1.60% (95% CI: 0.78-2.40), disease-related mortality rates were 1.02% (95% CI: 0.40-1.64) and 1.10% (95% CI: 0.46-1.73), and HIV-related mortality rates were 1.03% (95% CI: 0.40-1.65) and 0.99% (95% CI: 0.40-1.58). Treat All had no impact on all-cause [hazard ratio (HR) = 1.12, 95% CI: 0.58-2.18, P = 0.73], disease-related (HR = 1.04, 95% CI: 0.52-2.11, P = 0.90), or HIV-related mortality (HR = 0.93, 95% CI: 0.46-1.87, P = 0.83).

CONCLUSION

There was no immediate benefit of the Treat All strategy on mortality, nor evidence of harm. Longer follow-up of participants is needed to establish long-term consequences.

Efficient and Low-Cost Error Removal in DNA Synthesis by a High-Durability MutS

Enzyme-based error correction is a key step in de novo DNA synthesis, yet the inherent instability of error-correction enzymes such as MutS has hindered the throughput and efficiency of DNA synthesis workflows. Here we introduce a process called Improved MICC (iMICC), in which all error-correction steps of oligos and fragments within a complete gene-synthesis cycle are completed in a simple, efficient, and low-cost manner via a MutS protein engineered for high durability. By establishing a disulfide bond of L157C-G233C, full-activity shelf life of E. coli MutS (eMutS) was prolonged from 7 to 49 days and was further extended to 63 days via cellulose-bound 4 °C storage. In synthesis of 10 Cas9 homologues in-solution and 10 xylose reductase (XR) homologues on-chip, iMICC reduced error frequency to 0.64/Kb and 0.41/Kb, respectively, with 72.1% and 86.4% of assembled fragments being error-free. By elevating base accuracy by 37.6-fold while avoiding repetitive preparation of fresh enzymes, iMICC is more efficient and robust than the wild-type eMutS, and it is 6.6-fold more accurate and 26.7-fold cheaper than CorrectASE. These advantages promise its broad applications in industrial DNA synthesis.

High throughput quantification of the functional genes associated with RDX biodegradation using the SmartChip real-time PCR system

The explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a contaminant at many military sites. RDX bioremediation as a clean-up approach has been gaining popularity because of cost benefits compared to other methods. RDX biodegradation has primarily been linked to six functional genes (diaA, nfsI, pnrB, xenA, xenB, xplA). However, current methods for gene quantification have the risk of false negative results because of low theoretical primer coverage. To address this, the current study designed new primer sets using the EcoFunPrimer tool based on sequences collected by the Functional Gene Pipeline and Repository and these were verified based on residues and motifs. The primers were also designed to be compatible with the SmartChip Real-Time PCR system, a massively parallel singleplex PCR platform (high throughput qPCR), that enables quantitative gene analysis using 5,184 simultaneous reactions on a single chip with low volumes of reagents. This allows multiple genes and/or multiple primer sets for a single gene to be used with multiple samples. Following primer design, the six genes were quantified in RDX-contaminated groundwater (before and after biostimulation), RDX-contaminated sediment, and uncontaminated samples. The final 49 newly designed primer sets improved upon the theoretical coverage of published primer sets, and this corresponded to more detections in the environmental samples. All genes, except diaA, were detected in the environmental samples, with xenA and xenB being the most predominant. In the sediment samples, nfsI was the only gene detected. The new approach provides a more comprehensive tool for understanding RDX biodegradation potential at contaminated sites.

UNEXPECTED PRESENCE OF SOLUTE-FREE ZONES AT METAL-WATER INTERFACES

Solute-free zones, termed "exclusion zones" are routinely seen next to hydrophilic surfaces in aqueous solution. Here we report similar zones next to various metals. The largest, approximately 200 µm in width, was found adjacent to zinc. Other reactive metals, including aluminum, tin, lead, and tungsten exhibited distinct but smaller exclusion zones, while precious metals such as platinum and gold did not produce any. Electrical potential measurements showed positive potentials within the exclusion zones, while pH measurements revealed an abundance of OH^- groups in the aqueous regions beyond the exclusion zones. A correspondence was found between exclusion-zone size and the respective metal's position within the galvanic series. The presence of these interfacial exclusion zones is unexpected, and may shed new light on electrochemical processes taking place at metal interfaces.

The Ribosomal Database Project: improved alignments and new tools for rRNA analysis

The Ribosomal Database Project (RDP) provides researchers with quality-controlled bacterial and archaeal small subunit rRNA alignments and analysis tools. An improved alignment strategy uses the Infernal secondary structure aware aligner to provide a more consistent higher quality alignment and faster processing of user sequences. Substantial new analysis features include a new Pyrosequencing Pipeline that provides tools to support analysis of ultra high-throughput rRNA sequencing data. This pipeline offers a collection of tools that automate the data processing and simplify the computationally intensive analysis of large sequencing libraries. In addition, a new Taxomatic visualization tool allows rapid visualization of taxonomic inconsistencies and suggests corrections, and a new class Assignment Generator provides instructors with a lesson plan and individualized teaching materials. Details about RDP data and analytical functions can be found at http://rdp.cme.msu.edu/.

The ribosomal database project (RDP-II): introducing myRDP space and quality controlled public data

Substantial new features have been implemented at the Ribosomal Database Project in response to the increased importance of high-throughput rRNA sequence analysis in microbial ecology and related disciplines. The most important changes include quality analysis, including chimera detection, for all available rRNA sequences and the introduction of myRDP Space, a new web component designed to help researchers place their own data in context with the RDP's data. In addition, new video tutorials describe how to use RDP features. Details about RDP data and analytical functions can be found at the RDP-II website ().

A mutation in SART3 gene in a Chinese pedigree with disseminated superficial actinic porokeratosis

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is an uncommon autosomal dominant chronic disorder of keratinization, characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. Thus far, although two loci for DSAP have been identified, and the genetic basis and pathogenesis of this disorder have not been elucidated.

OBJECTIVES

To determine the locus of DSAP and identify the candidate gene(s) of the disease.

METHODS

Genome-wide scan and linkage analysis were performed in a six-generation Chinese family with DSAP. The coding exons of the candidate genes were sequenced to analyse and detect the nucleotide variations.

RESULTS

Linkage analysis showed that the maximum two-point lod score of 5.56 was obtained with the marker D12S79 at a recombination fraction theta of 0.00. Haplotype analysis defined the critical region for DSAP between D12S330 and D12S1612 on 12q24.1-24.2. By sequence analysis, we found a Val591Met mutation in SART3 in all affected individuals of the family.

CONCLUSION

SART3 is a candidate gene for DSAP, and is possibly involved in the pathogenesis of DSAP.

The Ribosomal Database Project (RDP-II): sequences and tools for high-throughput rRNA analysis

The Ribosomal Database Project (RDP-II) provides the research community with aligned and annotated rRNA gene sequences, along with analysis services and a phylogenetically consistent taxonomic framework for these data. Updated monthly, these services are made available through the RDP-II website (http://rdp.cme.msu.edu/). RDP-II release 9.21 (August 2004) contains 101,632 bacterial small subunit rRNA gene sequences in aligned and annotated format. High-throughput tools for initial taxonomic placement, identification of related sequences, probe and primer testing, data navigation and subalignment download are provided. The RDP-II email address for questions or comments is rdpstaff@msu.edu.

The Ribosomal Database Project (RDP-II): previewing a new autoaligner that allows regular updates and the new prokaryotic taxonomy

The Ribosomal Database Project-II (RDP-II) pro-vides data, tools and services related to ribosomal RNA sequences to the research community. Through its website (http://rdp.cme.msu.edu), RDP-II offers aligned and annotated rRNA sequence data, analysis services, and phylogenetic inferences (trees) derived from these data. RDP-II release 8.1 contains 16 277 prokaryotic, 5201 eukaryotic, and 1503 mitochondrial small subunit rRNA sequences in aligned and annotated format. The current public beta release of 9.0 debuts a new regularly updated alignment of over 50 000 annotated (eu)bacterial sequences. New analysis services include a sequence search and selection tool (Hierarchy Browser) and a phylogenetic tree building and visualization tool (Phylip Interface). A new interactive tutorial guides users through the basics of rRNA sequence analysis. Other services include probe checking, phylogenetic placement of user sequences, screening of users' sequences for chimeric rRNA sequences, automated alignment, production of similarity matrices, and services to plan and analyze terminal restriction fragment polymorphism (T-RFLP) experiments. The RDP-II email address for questions or comments is rdpstaff@msu.edu.

Competence of oat ( Avena sativa L.) shoot apical meristems for integrative transformation, inherited expression, and osmotic tolerance of transgenic lines containing hva1

Three oat ( Avena sativa L.) cultivars have been successfully transformed using an efficient and reproducible in vitro culture system for differentiation of multiple shoots from shoot apical meristems. The transformation was performed using microprojectile bombardment with two plasmids (pBY520 and pAct1-D) containing linked ( hva1-bar) and non-linked ( gus) genes. The hva1 and bar genes cointegrated with a frequency of 100% as expected, and 61.6% of the transgenic plants carried all three genes. Molecular and biochemical analyses in R0, R1 and R2 progenies confirmed stable integration and expression of all transgenes. Localization of the GUS protein in R0 and R1 plants revealed that high-expression of gus occurred in vascular tissues and in the pollen grains of mature flowers. The constitutive expression of HVA1 protein was observed at all developmental stages of transgenic plants, and was particularly stronger during the early seedling stages. R2 progeny of five independent transgenic lines was tested in vitro for tolerance to osmotic (salt and mannitol) stresses. As compared to non-transgenic control plants, transgenic plants maintained a higher growth and showed significantly ( P < 0.05) increased tolerance to stress conditions. Less than 10% of transgenic plants showed symptoms of wilting or death of leaves and, when these symptoms present were delayed in transgenic plants as compared to 80% of non-transgenic plants, either wilted or died. These symptoms confirmed the increased in vitro tolerance in hva1-expressing transgenic plants to non-transgenic plants, providing strong evidence that the HVA1 protein may play an important role in the protection of oats against salinity and possible water-deficiency stress conditions.

Ultrastructural evidence for vulnerability of hip region to fracture in the aged

OBJECTIVE

To probe ultrastructurally into the mechanism why hip region is the predilected site of fracture in aged people, yet with femoral head exempted.

METHODS

Proximal femoral ends were collected from 14 aged people, who had undergone endoprosthetic replacement for intra-capsular fracture of the femoral neck, and from 7 young men died of brain injury. These specimens were processed and subjected to scanning electron microscopic and transmission electron microscopic observation for bone resorption.

RESULTS

As compared with the specimens from young men, there were three types of bone resorption in the proximal femoral ends of aged people, i.e. osteoclastic resorption and osteocytic resorption of the trabeculae of cancellous bone, and osteoclastic resorption of Haversian systems of the cortical bone. In the proximal femoral ends of the young men, the arch structures composed of trabeculae in the femoral head showed a round or roundish configuration, while those at the femoral head-neck junction revealed an oval profile and those in the femoral neck exhibited a narrow oval contour. In the proximal femoral ends of the aged people, the morphological characteristics of the trabecular arch remained unchanged despite overt bone resorption.

CONCLUSIONS

Vulnerability of hip region to fracture in aged people is due to a decline in the structural strength of bone tissues of the proximal femoral ends resulting from osteoclastic and osteocytic resorption. The round and roundish trabecular arch of the femoral head can bear external forces from different directions, so that no fracture occurs here, while the oval and narrow oval arches at the head-neck junction and in the neck region fail to stand the horizontal external forces (abduction and adduction injuries), thereby fracture easily happens.

[Regulatory factors of osteogenic phenotypical experession by fibroblasts in vitro]

In order to explore further the regulatory factors to the potentiality in inducing osteogenesis by fibroblasts, the fibroblasts were isolated, and purified from human skin, and were grown in incubation in the media of EGF, IL-6, TNF-alpha and BMP2 at different concentrations for two weeks, then, the markers for osteogenic features were investigated by biochemistry, histochemistry and electron microscopic observations. It was found that the combined use of TNF-alpha and BMP2 could stimulate fibroblasts to secrete alkaline phosphatase, osteocalcin and collagen, and the morphological changes of the fibroblasts were also very striking. In the extracellular matrix, the collagen fibrils, with or without periodicity, were arranged regularly or randomly oriented, and numerous minute calcium granules were interspersed among them. The fibroblasts were interwoven one on top of another in the form of multilayer structure and on the surface, there were secreting granules and piling up of calcium crystals which coalessed steadily and increased in size in forming bony nodules. It was considered that TNF-alpha and BMP2 were capable of inducing the fibroblasts to form bone.

[Bioassay of TNF-alpha in synovial fluid and ultrastructural observation of synovium from patients with osteoarthritis]

OBJECTIVE

To better define the role of synovium in the pathogenesis of osteoarthritis (OA).

METHODS

We measured the bioactivity of tumor necrosis factor-alpha(TNF-alpha) in synovial fluid (SF) and examined the histologic and ultrastructural features of the synovium from patients with OA and from patients with acute and chronic traumatologic joint.

RESULTS

The results showed that the levels of TNF-alpha in SF from OA were significantly elevated. Marked fibrosis and thickened intima were found in OA synovium, with much dense collagen, which, in some cases, was banded, but no specific inflammatory changes were detected. Type B cells in OA synovium had the characteristics of organelles of cells active in synthesizing and secreting protein. Type A cells in OA synovium had the features of the macrophage.

CONCLUSION

Evident fibrosis in synovium may be either mediated by the cartilage degradation product or by the enhanced joint damage process in OA.

Ultrastructural investigation of calcification and ossification in experimental fracture healing with special reference to osteogenic role of fibroblasts

OBJECTIVE

To investigate ultrastructurally the process of calcification and ossification in experimental fracture healing.

METHODS

A standardized fracture of the radius was made in rabbits. Undecalcified callus tissues from different fracture regions were subjected to ultrastructural observation under transmission electron microscope.

RESULTS

In the mitochondria and membrane-bound vesicles of the fibroblasts, osteoblasts and chondrocytes, high electron density calcium granules were seen. These granules provided raw materials for the deposition of calcium salt crystals. Around these cells, round, oval or irregularly shaped matrix vesicles could also be discerned, and they became calcified and formed flocculent calcospherules. Then in the Type I collagen fibrils around the fibroblasts and osteoblasts, and in the Type II collagen fibrils around the chondrocytes, calcium salt crystals also appeared. Innumerable flocculent calcospherules and calcified collagen fibrils coalesced together, expanded and finally turned into pieces of bone tissues. The fibroblasts also possessed the indispensable prerequisites for calcification and ossification in fracture healing. They either transformed into osteocytes or degenerated, perished and eventually were replaced by bone tissues.

CONCLUSIONS

Sequence of events taking place in calcification and ossification in experimental fracture healing was depicted. Calcification of matrix vesicles and collagen fibrils triggered these processes. Evidence of osteogenic role played by fibroblasts was provided.

Osteoclastic resorption of Haversian systems in cortical bone of femoral neck in aged women. A scanning electron microscopic study

OBJECTIVE

To reveal the sequence of events of osteoclastic resorption taking place in the cortical bone of the femoral neck in aged women.

MATERIAL AND METHODS

The cross sections of cortical bones of the femoral neck from 7 aged women who underwent endoprosthetic replacement for intracapsular hip fracture, were processed and subjected to scanning electron microscopic observation.

RESULTS

The cortical bone sections revealed enlargement of the Haversian canals. On the inner linings of the enlarged canals many oval resorption lacunae could be found, reflecting osteoclastic resorption of the Haversian systems. The osteoclastic resorption with subsequent enlargement of the Haversian canals into round or oval cavities took place first over the inner portions of the cortical sections, thereby rendering these areas porotic (cancellization). These processes of the Haversian systems and canals then gradually emerged over the central and eventually over the outer areas of the cortical bone, and the entire cortical bone became porotic. Meanwhile, the inner porotic portion of the cortex turned into trabeculae (trabecularization) and became gradually resorbed, resulting in thinning of the medial cortex.

CONCLUSIONS

Cortical cancellization, trabecularization and thinning compromised the material strength of the femoral neck so that fracture would ensue even with trivial injury.

A scanning electron microscopic study of trabeculae in osteoporotic femoral head

OBJECTIVE

To investigate osteoclastic resorption in trabeculae of osteoporotic femoral head.

METHODS

Osteoporotic femoral heads were collected from 7 aged women with an average age of 72.4 years, who underwent endoprosthetic replacement for intracapsular hip fracture. Femoral head trabeculae from 3 young adults killed in traffic accidents served as control. The two types of specimens were processed and studied under scanning electron microscope.

RESULTS

The trabeculae of femoral head formed round or roundish arch structure. The columnar trabeculae of femoral head in the aged women showed overt osteoclastic resorption, manifested in thinning, tapering and perforation, resulting in formation of icicle-like trabeculae, which then became rounded, lost height and eventually turned into small tubercle. As a result, the inter-trabecular space enlarged markedly. Under high magnification, the trabeculae could be discerned oval, narrow oval or spindle-shaped. Howship resorption lacunae, which varied in size, depth and content, but all revealed punched-out margin. During bone resorption, the inorganic and organic components were successively resorbed. In the Howship lacunae and surrounding areas, newly formed collagen fibrils and bone tissues emerged, signifying reversal and new bone formation phases after bone resorption phase.

CONCLUSION

Osteoclastic resorption markedly compromises the structural integrity and strength of the trabeculae of the arch structure of the femoral head in the aged women.

[Osteoclastic resorption of Haversian system of femoral neck cortex in aged women]

Osteoclastic resorption was studied with scanning electron microscope on cross sections of cortical bone of femoral neck collected from 7 aged women with an average age of 72.4 years, who underwent endoprosthetic replacement for intracapsular hip fracture. The cortical bone sections revealed enlargement of the Haversian canals. On the inner linings of the enlarged canals there were many oval-shaped resorption lacunae, reflecting osteoclastic resorption of the Haversian systems. The osteoclastic resorption with subsequent enlargement of the Haversian canals into round or oval cavities took place first over the inner portions of the cortical sections, thereby rendering these areas porotic (cancellization). These processes of the Haversian system and canals then gradually emerged over the central and eventually over the outer areas of the cortical bone, and the entire cortical bone became porotic. In the meanwhile, the inner porotic portion of the cortex turned into trabeculae (trabecularization) and became gradually resorbed, resulting in thinning of the medial cortex. Cortical cancellization, trabecularization and thinning so compromised the material strength of the femoral neck that fracture would ensue even with trivial injury.

The effect of chronic clozapine on basal dopamine release and apomorphine-induced DA release in the striatum and nucleus accumbens as measured by in vivo brain microdialysis

Previous studies have produced conflicting results concerning the effect of chronic oral vs. parenteral (i.p.) clozapine administration on dopamine (DA) release and metabolism in the striatum and nucleus accumbens (n. accumbens) of freely moving rats using in vivo microdialysis. In this study, parenteral chronic clozapine (20 mg/kg/day for 21 days, i.p.) had no effect on basal DA release and metabolism in either region. Chronic treatment with parenteral clozapine also did not reverse the decrease in DA release and metabolism in striatum and n. accumbens produced by apomorphine (100 micrograms/kg, s.c.). These results differ significantly from a previous report following i.p. clozapine and confirm the results previously reported with oral clozapine.