Study on transient photocurrent induced by energy level defect of schottky diode irradiated by high power pulsed laser

The transient photocurrent is one of the key parameters of the spatial radiation effect of photoelectric devices, and the energy level defect affects the transient photocurrent. In this paper, by studying the deep level transient spectrum of a self-designed Schottky diode, the defect properties of the interface region of the anode metal AlCu and Si caused by high-temperature annealing at 150 ℃, 200 ℃ and 300 ℃ for 1200 h have been quantitatively analyzed. The study shows that the defect is located at the position of + 0.41 eV on the valence band, the concentration is 2.8 [Formula: see text] 1013/cm2, and the capture cross section is [Formula: see text] = 8.5 [Formula: see text] 1017. The impurity energy level mainly comes from the diffusion of Al atom in anode metal. We found that the defect did not cause the electrical performance degradation and obvious morphology change of the device, but the transient photocurrent increased significantly. The reason is that the high temperature treatment results in a growth in the density of states at the interface between AlCu-Si. The more mismatched dislocations and recombination center increased the reverse current of the heterojunction. The above view is proved by the TCAD simulation test.

[Epidemiological characteristics of Yersinia enterocolitica in patients with diarrhea from 2013 to 2019 in Pudong New Area, Shanghai]

Objective: To investigate the epidemiological characteristics of Yersinia enterocolitica in patients with diarrhea in Pudong New Area, Shanghai. Methods: Active surveillance of diarrhea was conducted in 14 sentinel hospitals (three tertiary-level hospitals, nine secondary-level hospitals, and two primary-level hospitals) from January 2013 to December 2019 in Pudong New Area of Shanghai, China base on their location, catchment area, and patient volume. Cold enrichment method was used to isolate Y. enterocolitica and further detection of bioserotype, virulence genes and antimicrobial susceptibility of the isolates were conducted. The difference of rates was determined using chi-square test or Fisher's exact test. Results: A total of 12 941 diarrhea cases were included, and 0.7% (88/12 941) cases were confirmed with Yersinia enterocolitica infection. 67.0% (59/88) cases were single infection, 33.0% (29/88) cases were mixed infections. Detection rates of Y. enterocolitica increased annually (0.3%-1.2%) and were highest in children<5 years of age (1.1%, 37/3 218) and in spring (1.1%, 32/2 998) (χ² were 18.64 and 9.76, respectively, P<0.05). 58.0% (51/88) cases had watery diarrhea, 15.9% (14/88) had fever and 14.8% (13/88) had vomiting. The predominant bioserotypes were 3/O:3 (53.4%, 47/88), followed by 1A/O:8 (15.9%, 14/88) and 1A/O:5(6.8%, 6/88), respectively. Bioserotype 3/O:3 counted for the highest proportions (89.2%, 33/37) in children <5 years of age. All the strains of bioserotype 3/O:3 harbored ail, ystA, yadA and virF genes, which encoded pathogenic Y. enterocolitica. 11/14 strain of 1A/O:8 and 4/6 strains of 1A/O:5 harbored ystB gene. Most strains were resistant to ampicillin (80.7%,71/88) and amoxicillin/clavulanic acid (71.6%,63/88), and 63.8% (56/88) strains were multidrug resistance (MDR). The difference of antimicrobial resistance rates between 3/O:3 and non 3/O:3 was statistically significant in ampicillin, cefoxitin, nalidixic acid, tetracycline and ampicillin/sulbactam (χ² was 14.68, 43.80, 41.86, 30.54 and 5.07, respectively, P<0.05). Conclusion: The detection rate of Yersinia enterocolitica was higher in children than in adults in Pudong New Area, Shanghai. The predominant bioserotype was pathogenic 3/O:3 with multidrug resistance.

[Antimicrobial resistance and molecular epidemiology of foodborne Yersinia enterocolitica in Pudong New District, Shanghai]

Objective: To investigate the antimicrobial resistance and molecular epidemiology of foodborne Yersinia (Y.) enterocolitica in Pudong New District of Shanghai. Methods: Four kinds of raw food samples were collected in retail circulation sites in Pudong from 2012 to 2016. Cold enrichment method was used to isolate Y. enterocolitica and further detection of biotype, serotype, virulent genes, antimicrobial susceptibility of the isolates and pulsed field gel electrophoresis (PFGE) were conducted. Results: A total of 3 900 raw food samples were collected during this period, including poultry product (n=590), livestock product (n=1 074), aquatic product (n=1 488), vegetable (n=748), in which 111 (2.8%) were contaminated by Y. enterocolitica. The detection rates of Y. enterocolitica in poultry product samples (5.3%, 31/590) and livestock product samples (4.5%, 48/1 074) were higher than those in aquatic product samples (1.6%, 24/1 488) and vegetable samples (1.1%, 8/748). The predominant biotype was 1A (95.5%) and predominant serotype was O∶8 (42.3%). All the strains lacked ail, ystA, yadA and virF genes, which encoded pathogenic Y. enterocolitica. Seventy six (68.5%) strains harbored ystB gene, in which 35 (31.5%) belonged to 1A/O∶8/ystB pattern. Most strains were resistant to ampicillin (74.8%) and amoxicillin/clavulanic acid (70.3%), and non-sensitive rate to Cefoxitin was over 50.0%. No third generation cephalosporin or fluoroquinolone resistant strains were detected, but 38.7% (43/111) strains were multidrug resistant (MDR). Serotype O∶8 and O∶5 strains had 44 and 18 PFGE patterns, respectively. Conclusions: The main foodborne exposure sources of Y. enterocolitica in raw food were poultry and livestock products in Pudong New District. 1A/O∶8/ystB was the predominant pattern with potential pathogenicity despite lacks of typical pathogenic virulent genes. The antimicrobial resistant rates of Y. enterocolitica were at a low level, but MDR strains still existed. Molecular types of the isolates showed highly genetic diversity.

Changes of blood pressure, serum inflammatory factors and endothelin levels in patients with hypertension under rehabilitative aerobic exercise

The aim of this study was to evaluate the effects of rehabilitative aerobic exercise on blood pressure, serum inflammatory factors, endothelin and quality of life in patients with hypertension. Ninety patients with mild hypertension visiting West China Hospital of Sichuan University from June 2017 to December 2017 were enrolled and randomly divided into an experimental group and a control group. Patients in both groups were given a low-salt diet, and the experimental group was given an extra three-month treadmill training. Systolic blood pressure (SBP), diastolic blood pressure (DBP), serum tumor necrosis factor α (TNF-α), serum interleukin-6 and endothelin-1, body mass index (BMI), triglyceride (TG) and other indicators were examined in both groups before and after exercise, SF-36 scale was used to evaluate the quality of life. The results showed that after 3 months of exercise, SBP and DBP in the experimental group were significantly lower than those in the control group (P less than 0.05). Compared with the control group, the concentrations of TNF-α, interleukin-6 and endothelin-1 in the experimental group were significantly decreased (P less than 0.05). Correlation analysis showed that IL-6 was positively correlated with SBP (P less than 0.05), and TNF-α and ET-1 were positively correlated with diastolic blood pressure (P less than 0.05). The general health status, energy, mental health, social function, emotional function and health changes of the experimental group were significantly improved compared with before exercise (P less than 0.05). In conclusion, rehabilitative aerobic exercise can lower blood pressure and improve the overall quality of life in mild hypertension patients by inhibiting vascular inflammation and lowering plasma endothelin-1.

MicroRNA-139 modulates Alzheimer's-associated pathogenesis in SAMP8 mice by targeting cannabinoid receptor type 2

Alzheimer's disease (AD) is a neurodegenerative disorder, and is the most common type of dementia in the elderly population. Growing evidence indicates that microRNAs (miRNAs) play a crucial role in neuroinflammation associated with AD progression. In this study, we analyzed the expression of microRNA-139 (miR-139) as well as the learning and memory function in AD. We observed that the miR-139 expression was significantly higher in the hippocampus of aged senescence accelerated mouse prone 8 (SAMP8) mice (2.92 ± 0.13) than in the control mice (1.49 ± 0.08). Likewise, the overexpression of miR-139 by means of hippocampal injection impaired the hippocampus-dependent learning and memory formation. In contrast, the downregulation of miR-139 in mice improved learning and memory function in the mice. The level of cannabinoid receptor type 2 (CB2), a potential target gene of miR-139, was inversely correlated with the miR-139 expression in primary hippocampal cells. Furthermore, we demonstrated that miR-139 inversely modulated the responses to proinflammatory stimuli. Together, our findings demonstrate that miR-139 exerts a pathogenic effect in AD by modulating CB2-meditated neuroinflammatory processes.

Fluid flow induced calcium response in osteoblasts: mathematical modeling

Fluid flow in the bone lacuno-canalicular network can induce dynamic fluctuation of intracellular calcium concentration ([Ca(2+)](i)) in osteoblasts, which plays an important role in bone remodeling. There has been limited progress in the mathematical modeling of this process probably due to its complexity, which is controlled by various factors such as Ca(2+) channels and extracellular messengers. In this study we developed a mathematical model to describe [Ca(2+)](i) response induced by fluid shear stress (SS) by integrating the major factors involved and analyzed the effects of different experimental setups (e.g. [Ca(2+)](i) baseline, pretreatment with ATP). In this model we considered the ATP release process and the activities of multiple ion channels and purinergic receptors. The model was further verified quantitatively by comparing the simulation results with experimental data reported in literature. The results showed that: (i) extracellular ATP concentration has more significant effect on [Ca(2+)](i) baseline (73% increase in [Ca(2+)](i) with extracellular ATP concentration varying between 0 and 10 μM), as compared to that induced by SS (25% variation in [Ca(2+)](i) with SS varying from 0 to 3.5 Pa); (ii) Pretreatment with ATP-medium results in different [Ca(2+)](i) response as compared to the control group (ATP-free medium) under SS; (iii) Relative [Ca(2+)](i) fluctuation over baseline is more reliable to show the [Ca(2+)](i) response process than the absolute [Ca(2+)](i) response peak. The developed model may improve the experimental design and facilitate our understanding of the mechanotransduction process in osteoblasts.

Altered p-JAK1 expression is associated with estrogen receptor status in breast infiltrating ductal carcinoma

The mammalian Janus kinase (JAK) family consists of four members, namely JAK1, JAK2, JAK3 and TYK2, which play a critical role in cytokine/growth factor signaling and is increasingly associated with human cancers. Aberrant activation of these non-receptor tyrosine kinases may contribute to carcinogenesis. Herein, we focused on exploring the potential role of p-JAK1 in breast cancer. The expression profiles of p-JAK1 were analyzed in 68 pairs of cancer and non-cancer breast tissues from the same infiltrating ductal carcinoma case by using immunoblotting technique. The results obtained were further correlated with clinicopathological characteristics. Intriguingly, p-JAK1 expression was decreased in 55.9% of breast cancer tissues as compared to the matched non-cancer tissues. Further immunohistochemistry study showed an intense p-JAK1 staining predominantly in adjacent normal breast tissues but not the matched cancer lesions. Decreased p-JAK1 expression in breast cancer tissues was significantly correlated with positive estrogen receptor (ER) status and increased tumor size (p=0.010 and 0.009). We also found that p-JAK1 expression was high in ERalpha-negative breast cancer cell lines but was low in ERalpha-positive breast cell lines. Transfection of ERalpha-positive MCF-7 cells with an ERalpha-specific siRNA upregulated the expression of p-JAK1. In summary, our results indicated that an altered p-JAK1 expression might be involved in the development of breast infiltrating ductal carcinoma in an ERalpha-related manner.

Effect of HCH Contamination of Diet on the Growth Performance and Immune and Antioxidant Ability in Growing/Finishing Pigs

The effects of hexachlorocyclohexane (HCH) on growth performance and immune and oxidative stress in growing/finishing pigs were studied. Seventy-two pigs, with equal numbers of barrows and gilts, of the same genotype (Duroc x Landrace x Large White), were randomly assigned to three groups receiving the same basal diet, exposed to 0, 0.4 and 0.8 mg/kg technical HCH, respectively, for 90 days. Six pigs from each group were randomly picked out and slaughtered on a finishing feeding trial. The result showed that addition of HCH did not affect the growth performance significantly but increased the weight of kidney and thymus significantly. Total serum IgG and IgM were elevated significantly, but there were no significant differences in serum IgA, C3 and C4 among the groups. Addition of HCH to feedstuff reduced superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GSH-Px) activities in liver, reduced serum catalase (CAT) activity, and increased serum malondialehyde (MDA). Moreover, the activities of serum alanine aminotransferase and alkaline phosphatase were increased significantly. Addition of 0.4 mg/kg or 0.8 mg/kg HCH did not affect the growth performance but affected the immune and antioxidant potential.

Parallel compensatory and pathological events associated with tau pathology in middle aged individuals with Down syndrome

Aged individuals with Down syndrome (DS) develop senile plaques and neurofibrillary tangles consistent with Alzheimer disease (AD). Prior to or in parallel with AD pathology, compensatory growth responses may occur. Immunohistochemistry and confocal microscopy studies in the hippocampus from 15 individuals ranging in age from 5 months to 67 years compared markers of normal and abnormal tau accumulation (phosphorylated tau [AT8, MC-1], tau-1, N-terminal tau) with the extent and location of neuronal growth marker immunoreactivity (BDNF, GAP-43, MAP-2). In middle age (30-40 years), prior to entorhinal neuron loss, the earliest tau accumulation occurred in the outer molecular layer (OML), which was consistent with both pathological and compensatory fetal tau expression. These events were followed at a later age, associated with entorhinal neuron loss, by an increase in GAP-43. Hilar neurons exhibiting a sprouting morphology were also noted. Age-dependent observations in the DS brain in the current study parallel hippocampal compensatory responses described in entorhinal cortex lesion studies in rodents. Thus, compensatory growth responses may occur in DS prior to extensive AD pathology and may be one mechanism underlying observations in PET studies of hypermetabolism in the entorhinal cortex of individuals with DS.

Arsenite-induced nitric oxide generation is cell cycle-dependent and aberrant in NBS cells

Exposure to arsenic has been reported to cause DNA damage and eventually the occurrence of bladder, lung and skin cancers. A previous report has demonstrated that arsenite-induced phosphorylation of Mre11, a protein involved in the repair of DNA double strand breaks (DSBs), is M phase-dependent and requires the Nijmegen breakage syndrome (NBS) protein, NBS1 [DNA Repair 1 (2002) 137]. Furthermore, arsenite treatment arrests cells at the M phase and the cells eventually go through apoptosis [Biochemical Pharmacology 60 (2000) 771]. Here we demonstrate that arsenite treatment enhances the generation of nitric oxide (NO), and that the enhanced NO generation is dominant at the G2/M phase. Arsenite-induced NO generation is impaired in DSB repair-defective NBS cells, but not in NBS1-reconstituted NBS cells, suggesting NBS1 is required for effective NO generation. In summary, our study showed, for the first time, that arsenite-induced NO generation is cell-cycle- and NBS1-dependent.

Changes in vesicourethral function following laparoscopic hysterectomy versus abdominal hysterectomy

OBJECTIVE

To assess whether total hysterectomy is associated with increased postoperative vesicourethral abnormalities.

SAMPLE

Forty-five patients had a laparoscopic hysterectomy and 36 patients had a total abdominal hysterectomy.

DESIGN

Before and after hysterectomy, patients underwent a urinalysis, a personal interview, and an urodynamic study.

RESULTS

Of the laparoscopic hysterectomy group, 27 patients (60%) exhibited urinary symptoms preoperatively, and 22 patients (48.9%) remained symptomatic following surgery. There was no significant change in the number of women with one or more urinary symptoms, but the incidence of urinary frequency and stress incontinence decreased significantly following hysterectomy (p < 0.05). Of the total abdominal hysterectomy group, preoperative voiding symptoms were present in 22 patients (61.1%). After surgery, urinary symptoms were present in 19 patients (52.8%). Some patients did not complain of any urinary frequency or stress incontinence following hysterectomy, but this figure did not differ significantly (p > 0.05). Maximal urethral closure pressure and maximal cystometric capacity demonstrated significant increases for both groups following surgery.

CONCLUSIONS

The results indicated that total hysterectomy, either laparoscopic or total abdominal hysterectomy, did not significantly increase the subjective and objective incidence of vesicourethral dysfunction. On the contrary, some patients experience a substantial improvement of pre-existing urinary frequency or stress incontinence, partly as a result of an increase in the maximal urethral closure pressure and total bladder capacity following hysterectomy.

The effects on vesicourethral function following laparoscopic hysterectomy

The aim of our study is to determine whether laparoscopic hysterectomy is associated with increased postoperative urinary symptoms and to assess the change in urodynamic parameters after operation. Forty-five women were arranged for laparoscopic hysterectomy (LH). Each patient received urinalysis, interview, and urodynamic study including uroflowmetry, filling and voiding cystometry and urethral pressure profilometry before and after hysterectomy. A total of 27 patients (60%) had urinary symptoms preoperatively. After operation, only 22 patients (48.9%) remained symptomatic. There was no significant change in the number of women with one or more voiding symptoms before and after surgery, but the incidence of urinary frequency and stress incontinence decreased significantly after laparoscopic hysterectomy (P < 0.05). In addition, maximal urethral closure pressure and maximal cystometric capacity showed significant increases after operation. They were 73.1 cm H2O (range: 49-114) vs 104.4 cm H2O (range: 60-147) (P < 0.001), and 363.3 ml (range: 287-423) vs 396.1 ml (range: 265-515) (P < 0.001), respectively. The result indicated that laparoscopic hysterectomy did not significantly increase the subjective or objective incidence of vesicourethral dysfunction. On the contrary, some patients might be cured of urinary frequency or stress incontinence postoperatively.

Pseudo-Meigs syndrome and elevated levels of tumor markers associated with benign ovarian tumors--two case reports

Elevated tumor markers for a post-menopausal woman presenting with a multilocular adnexal mass, ascites, and pleural effusion were interpreted as being highly suspicious of malignancy. This paper describes two cases of ovarian tumors presenting with all signs of malignancy. Following surgical excision of the masses, and histopathological assay, a benign pure struma ovarii and a mucinous cystadenoma were diagnosed by pathologists. The immediate and complete resolution of symptoms were achieved post-operatively, and the previously-evident abnormal tumor markers rapidly declined to the normal range, the two tumors were subsequently classified as pseudo-Meigs' syndromes.

Cloning and characterization of a blue fluorescent protein from Vibrio vulnificus

The blue fluorescent protein (BFPVV) gene bfpvv from Vibrio vulnificus CKM-1 was cloned and sequenced. The transformants exhibited blue fluorescence when irradiated by UV source. Nucleotide sequence analysis predicted an ORF of 717 bp encoding a 239-amino-acid polypeptide with a calculated molecular mass of 25.8 kDa. The nucleotide sequence of the bfpvv gene and its deduced amino acid sequence showed significant homology to those of the short-chain dehydrogenase/reductase (SDR) family proteins from various organisms. Some functionally important residues in SDR were strictly conserved in BFPVV, such as an active-site Tyr145, a catalytic site Lys149, and a common GlyXXXGlyXGly pattern in the N-terminal part of the molecule. By changing three amino acid residues, Tyr145, Lys149, and Gly9 to Phe, Ile, and Val, respectively, it was found that the G9V mutant did not generate blue fluorescence, while mutants Y145F and K149I have 126 and 68.5% fluorescence compared with the wild-type BFPVV.

Endometrioma in a cesarean section scar--a case report

Scar endometriosis remains quite rare and there is only one case report in the literature of plastic surgery. We present a case of endometrioma appearing on the cesarean section scar. The classic symptom was a painful scar that became swollen and more tender during menstruation. The cause of surgical scar endometriosis is believed to be iatrogenic transplantation of endometrium to the surgical wound. Surgical excision remains the treatment of choice. This entity must be kept in mind by plastic surgeons evaluating patients who present with soft-tissue masses of the abdominal wall in the setting of previous combined hysterectomy and abdominoplasty.

A case of pulmonary endometriosis--a rare case report and a successful treatment experience

Endometriosis is a common disease found in reproductive age women, but pulmonary endometriosis is rare. We present a 21-year-old female with catamenial chest pain, chest tightness, severe cough, and hemoptysis. Though we could not find any definite intrapulmonary endometriotic lesion by computed tomography and bronchoscope, she was diagnosed to have pulmonary endometriosis due to the typical clinical symptoms. After 6 months of GnRH agonist application, the symptoms were completely relieved. She has been followed up and has been symptoms free for at least 6 months after administration of GnRH agonist.

Activated caspase-3 expression in Alzheimer's and aged control brain: correlation with Alzheimer pathology

Several studies have suggested that activated caspase-3 has properties of a cell death executioner protease. In this study, we examined the expression of activated caspase-3 in AD and aged control brains. Activated caspase-3 immunoreactivity was seen in neurons, astrocytes, and blood vessels, was elevated in AD, and exhibited a high degree of colocalization with neurofibrillary tangles and senile plaques. These data suggest that activated caspase-3 may be a factor in functional decline and may have an important role in neuronal cell death and plaque formation in AD brain.

Briaexcavatolides K-N, new briarane diterpenes from the gorgonian Briareum excavatum

Four new briarane diterpenes, briaexcavatolides K-N (1-4), along with a known diterpene, 5, have been isolated from the Taiwanese gorgonian Briareum excavatum. The structures of the new metabolites were established by extensive spectral analyses. Furthermore, the structure, including the relative configuration of briaexcavatolide K (1), was confirmed by a single-crystal X-ray analysis. Briaexcavatolides K and L (1 and 2) are the only briarane diterpenes known to possess hydroxyl groups at the C-8beta and C-17alpha positions, respectively. Cytotoxicity of these metabolites toward various cancer cell lines also is described.

Astrocytes degenerate in frontotemporal dementia: possible relation to hypoperfusion

To understand the extent and specificity of astrocyte pathology in sporadic frontotemporal dementia (FTD), we examined several FTD cases for molecular and morphologic characteristics of astrocyte degeneration. We quantified reactive and degenerating astrocytes in sections of frontal, temporal, parietal, and occipital cortex identified using glial fibrillary acidic protein (GFAP) immunoreactivity, terminal deoxynucleotidyl transferase (TdT) labeling, and morphological characteristics and compared them with nondemented, age-matched control brains. Conventional and confocal microscopy revealed that a subpopulation of GFAP(+) astrocytes exhibited positive TdT labeling and beading of their processes in the frontal, temporal, and parietal cortices in 5 of 7 FTD cases that also exhibited gliosis. This morphology was reproduced in cultured astrocytes using ischemic insults. Degenerating astrocytes in FTD correlated inversely with cerebral blood flow as measured by single photon emission computed tomography (SPECT) analysis of (133)Xe inhalation (r = 0.55, p < 0.05). Furthermore, areas of significant astrogliosis corresponded to areas of SPECT hypoperfusion, suggesting that astrocytes may be affected by or perhaps have a causal role in the disturbances of cerebral perfusion in FTD.

Correlation between caspase activation and neurofibrillary tangle formation in Alzheimer's disease

Although evidence suggests that neurofibrillary tangles (NFTs) and neuronal cell loss are prominent features of Alzheimer's disease (AD), the relationship between the two remains unknown. In the present study, the relationship between the activation of apoptotic mechanisms and NFT formation in AD was investigated using a caspase-cleavage site-directed antibody to fodrin, an abundant neuronal cytoskeleton protein. This antibody recognized cleavage products of fodrin after digestion by caspase-3, but did not recognize full-length fodrin. In vitro analysis of this fodrin caspase-cleavage product (CCP) antibody demonstrates that it is a specific probe for the detection of apoptotic but not necrotic pathways in cultured neurons. To determine whether caspases cleave fodrin in vivo, tissue sections from controls and AD were immunostained for fodrin (CCPs). Although no staining was observed in control cases, labeling of neurons was observed in the hippocampus of all AD cases, which increased as a function of disease progression. To determine a possible relationship between caspase activation and NFT formation, double-labeling experiments with fodrin CCP and PHF-1 were performed. Co-localization of these markers was observed in many neurons, and quantitative analysis showed that as the extent of NFT formation increased, there was a significant corresponding increase in fodrin CCP immunolabeling (r = 0.84). Taken together, these results provide evidence for the activation of apoptotic mechanisms in neurons in the AD brain and suggest that there is an association between NFT formation and the activation of apoptotic pathways in AD.

DNA damage and activated caspase-3 expression in neurons and astrocytes: evidence for apoptosis in frontotemporal dementia

Frontotemporal dementia (FTD) is a neurodegenerative disease which affects mainly the frontal and anterior temporal cortex. It is associated with neuronal loss, gliosis, and microvacuolation of lamina I to III in these brain regions. In previous studies we have described neurons with DNA damage in the absence of tangle formation and suggested this may result in tangle-independent mechanisms of neurodegeneration in the AD brain. In the present study, we sought to examine DNA fragmentation and activated caspase-3 expression in FTD brain where tangle formation is largely absent. The results demonstrate that numerous nuclei were TdT positive in all FTD brains examined. Activated caspase-3 immunoreactivity was detected in both neurons and astrocytes and was elevated in FTD cases as compared to control cases. A subset of activated caspase-3-positive cells were also TdT positive. In addition, the cell bodies of a subset of astrocytes showed enlarged, irregular shapes, and vacuolation and their processes appeared fragmented. These degenerating astrocytes were positive for activated caspase-3 and colocalized with robust TdT-labeled nuclei. These findings suggest that a subset of astrocytes exhibit degeneration and that DNA damage and activated caspase-3 may contribute to neuronal cell death and astrocyte degeneration in the FTD brain. Our results suggest that apoptosis may be a mechanism of neuronal cell death in FTD as well as in AD (228).

Excavatolides U-Z, new briarane diterpenes from the gorgonian briareum excavatum

A recent study of the EtOAc extract of the gorgonian Briareum excavatum afforded six new diterpenes of the briarane skeleton, excavatolides U-Z (1-6). The structures and relative stereochemistry of metabolites 1-6 were assigned on the basis of NMR studies and chemical methods. The structure, including the relative configuration of excavatolide U (1), was further confirmed by a single-crystal X-ray analysis. Some of the excavatolides have displayed significant cytotoxicity toward P-388 and HT-29 tumor cells.

Bcl-2 facilitates recovery from DNA damage after oxidative stress

Oxidative stress is a major factor affecting the brain during aging and neurodegenerative diseases such as Alzheimer's disease (AD). Understanding the mechanisms by which neurons can be protected from oxidative stress, therefore, is critical for the prevention and treatment of such degeneration. Previous studies have shown that bcl-2 expression is increased in neurons with DNA damage in AD and bcl-2 has an antioxidant effect. The goal of this study is to document the effects of oxidative insults on mitochondrial and nuclear DNA in PC12 cells and determine the extent to which bcl-2 prevents damage or facilitates repair. Using extralong PCR to amplify nuclear and mitochondrial DNA, the time course of DNA damage and repair was determined. Within minutes after exposure of cells to low concentrations of hydrogen peroxide and peroxynitrite, significant mitochondrial and nuclear DNA damage was evident. Mitochondrial DNA was damaged to a greater degree than nuclear DNA. Expression of bcl-2 in PC12 cells inhibited nitric oxide donor (sodium nitroprusside)- and peroxynitrite-induced cell death. Although oxidative insults caused both genomic and mitochondrial DNA damage in cells expressing bcl-2, recovery from DNA damage was accelerated in these cells. These results suggest that neuronal up-regulation of bcl-2 may facilitate DNA repair after oxidative stress.

Excavatolides F-M, new briarane diterpenes from the gorgonian Briareum excavatum

Eight new briarane-type diterpenes, excavatolides F-M (1-8), have been isolated from the gorgonian Briareum excavatum. The structures and relative stereochemistry of these compounds were established by spectral analysis and chemical methods. The cytotoxicity of these compounds toward various cancer cell lines has also been determined.

Plaque biogenesis in brain aging and Alzheimer's disease. II. Progressive transformation and developmental sequence of dystrophic neurites

Plaque-associated dystrophic neurites are a common pathological feature in the brains of patients with Alzheimer's disease (AD). In the present study, we investigated the relative abundance and progressive transformation of the amyloid precursor protein (APP), neurofilament (NF) and paired helical filament (PHF) tau-positive dystrophic neurites, within plaques in non-demented controls versus plaque-associated dystrophic neurites in mild or severe AD using double and triple immunolabeling. We also determined the argentophilia of the various sub-populations of dystrophic neurites. In aged non-demented brain, approximately half of the APP-positive plaques contained NF-immunopositive dystrophic neurites; rarely were PHF/tau-positive dystrophic neurites detectable. In contrast, in the AD brain, three-fourths of the APP-positive plaques contained NF-positive dystrophic neurites and half contained PHF/tau neurites. We also observed focal patches of hyper-phosphorylated NF and/or PHF/tau within APP-immunopositive dystrophic neurites, which appeared similar to retrograde degeneration, whereas we never observed focal accumulations of APP within NF- or PHF/tau-positive fibers. We hypothesize that plaque-associated dystrophic neurites within plaques develop in a particular sequence: APP-positive dystrophic neurites appear first and are non-argentophilic. This is followed by the appearance of NF-positive dystrophic neurites, where a subset of NF-positive dystrophic neurites are lightly argentophilic. Over time, PHF/tau-positive dystrophic neurites develop and are strongly argentophilic. These data suggest that dystrophic neurites can develop retrogradely from focal plaque damage to induce somatic and dendritic degeneration and potentially contribute to neurofibrillary tangle formation.

GADD45 is induced in Alzheimer's disease, and protects against apoptosis in vitro

Expression of the growth arrest DNA damage-inducible protein, GADD45, has recently been reported to be induced by a wide range of stimuli, especially those that produce a high level of base pair damage. We have investigated the expression of GADD45 in brain tissue obtained from patients suffering from Alzheimer's disease (AD). Our results demonstrate that many neurons express the GADD45 protein, and that expression of this protein in neurons is associated with expression of the anti-apoptotic protein Bcl-2, and the presence of DNA damage, but not closely associated with tangle-bearing neurons. Additionally, cell lines overexpressing this protein confer resistance to apoptosis induced by DNA damage agent, suggesting that this protein may participate in cell survival mechanisms.

Cloning and sequence analysis of the Candida tropicalis URA3 gene encoding orotidine-5'-phosphate decarboxylase

An integrative transformation system was established for a phenol-utilizing strain of Candida tropicalis M4. The system is based on an auxotrophic mutant host of C. tropicalis U-6 that is defective in orotidine-5'-phosphate decarboxylase (ODCase). As a selectable marker, we isolated and characterized the C. tropicalis URA3 gene, which codes for ODCase. The gene was cloned by complementation of the ura3 mutation of Sachharomyces cerevisiae SHY-3 and the pyrF mutation of Escherichia coli. The C. tropicalis U-6 was transformed by plasmid containing the C. tropicalis URA3 gene at a frequency of 1 to 10 transformants per microgram of plasmid DNA. When the URA3 gene was expressed in E. coli minicells, a 30-kDa protein was identified. Nucleotide sequence analysis revealed the presence of an open reading frame, encoding a protein of 268 amino acids with a calculated molecular mass of 29.7 kDa. The nucleotide sequence of URA3 gene and its deduced amino acid sequence showed significant homology to those of the ODCase of other fungal species.

Hysteroscopic resection of vaginal septum in an adolescent virgin with obstructed hemivagina

This article reports on one patient with a double uterus, unilateral vaginal obstruction, with hemi-haematocolpos and ipsilateral renal agenesis. Early accurate diagnosis followed by the excision of the obstructing vaginal septum offers complete relief of symptoms, while preserving reproductive capacity. Unlike conventional excision of vaginal septum, we used resectoscope excision with cutting electrode under continuous pure distilled water irrigation. The postoperative course was uneventful, and haematocolpos and severe dysmenorrhoea disappeared. The resected vaginal area revealed re-epithelialization by hysteroscope follow-up one year after resection. With advancements in resectoscopic operation, evaluation and treatment of vaginal disorders in babies and virgins is very feasible.

Transmission of hepatitis C virus infection to tree shrews

Although hepatitis C virus (HCV) infection can be reproduced in chimpanzees, these animals are rare and expensive. Tree shrews (tupaias) are small animals, closely related to primates, which adapt easily to a laboratory environment. In this work we have investigated the susceptibility of Tupaia belangeri chinensis to HCV infection. Tupaias caught in the wild in Yunnan (China) were inoculated in China with HCV genotype 1b (study A) and in Spain with a mixture of genotypes 1b, 1a, and 3 (study B). In study B tupaias were divided into three groups: group I was inoculated without previous manipulation, group II received 750 cGy of X-ray whole-body irradiation before inoculation, and group III was used as control. Transient or intermittent viremia occurred in 34.8% (8/23) and anti-HCV in 30.4% (7/23) of tupaias in study A. In study B a transient viremia was detected in 20% (2/10) in group I and in 50% (2/4) in group II. Anti-HCV was found in 1 tupaia from group I and in 3 from group II: Viremia lasted for longer and anti-HCV tended to reach higher titers in animals which received total body irradiation. ALT elevations and nonspecific pathological changes occurred in inoculated tupaias; however, the wild nature of the animals precludes the interpretation of these changes as solely due to HCV infection. In summary our results show that T.b. chinensis are susceptible to HCV and that whole-body irradiation may possibly increase the efficiency of the infection. These animals may serve as an in vivo system for culturing HCV and addressing pathophysiological and therapeutic issues of HCV infection.

Transneuronal degeneration in the spread of Alzheimer's disease pathology: immunohistochemical evidence for the transmission of tau hyperphosphorylation

Neurofibrillary tangles and dystrophic neurites appear to develop in a highly characteristic spatial and temporal sequence in AD. In order to examine the nature of the cellular progression we have studied the trisynaptic entorhinal, dentate gyrus, CA3/4 circuit, using an antibody to hyperphosphorylated tau which is a biochemical marker for tangle formation. In early AD cases, we found numerous ATB-stained boutons in the outer molecular layer of the dentate gyrus, the termination field of neurons from the entorhinal cortex. These AT8-stained boutons co-labeled with synaptophysin, indicating that they represent synaptic boutons in an early state of degeneration. Since the labeled boutons were apposed to or clustered around dendrites or soma that lacked or had less intense staining for AT8 or PHF-1, it appeared that presynaptic events preceded postsynaptic neurofibrillary tangle formation. Furthermore, as a function of disease progression, the pattern of degeneration moved through the circuit. In this progression tau, which is normally localized to axons, becomes redistributed into dendrites and hyperphosphorylated. These observations support the hypothesis that the presynaptic terminal changes may promote the formation of initial neurofibrillary pathology in the postsynaptic neurons via anterograde transneuronal mechanisms and that this initiates a breakdown of routing and sorting mechanisms for the cytoskeletal protein tau.

Neuronal DNA damage precedes tangle formation and is associated with up-regulation of nitrotyrosine in Alzheimer's disease brain

The relationship of neuronal DNA damage to tangle-bearing neurons and nitrotyrosine (NT) expression, a neurochemical marker of oxidative damage mediated by peroxynitrite, was examined in visual cortex of AD patients. Many terminal deoxynucleotidyl transferase (TdT)-positive neurons were detected and the majority (93%) of these TdT-labeled neurons lacked evidence of tangle formation. NT expression was elevated in AD cases and most TdT-labeled nuclei also showed strong NT immunoreactivity. These data suggest the hypothesis that the neurons with DNA damage in the absence of tangle formation may degenerate by tangle-independent mechanisms and that oxidative damage may contribute to such mechanisms in AD.

Cloning and sequence analysis of a novel hemolysin gene (vllY) from Vibrio vulnificus

A gene (vllY) encoding a novel hemolysin of Vibrio vulnificus CKM-1 has been cloned and sequenced. When the vllY gene was expressed in minicells, a unique peptide of approximately 40 kDa was identified. Subcellular fractionation of Escherichia coli cells carrying the vllY gene indicated that the VllY protein was distributed in both the cytoplasmic and the periplasmic fractions, with the notable ability to appear in the latter compartment. Nucleotide sequence analysis predicted a single open reading frame of 1,071 bp encoding a 357-amino acid polypeptide with an estimated pI of 5.02. The deduced amino acid sequence of VllY showed high similarity to the sequence of legiolysin, responsible for hemolysis, pigment production, and fluorescence in Legionella pneumophila. The enzyme also exhibited sequence homology to the MelA protein sequence of Shewanella colwelliana and the sequences of 4-hydroxyphenylpyruvate dioxygenase family proteins from various organisms. PCR screening and Southern blotting of V. vulnificus strains revealed that all of the 41 V. vulnificus clinical isolates contained vllY-like genes.

Bax protein expression is increased in Alzheimer's brain: correlations with DNA damage, Bcl-2 expression, and brain pathology

We have shown that many neurons in Alzheimer's disease (AD) exhibit terminal deoxynucleotidyl transferase (TdT) labeling for DNA strand breaks, and upregulation of Bcl-2 is associated with neurons exhibiting nuclear DNA fragmentation, while downregulation of Bcl-2 is associated with tangle-bearing neurons in AD brains. Consequently, we examined the expression of bcl-associated X (Bax) protein in AD brain. Immunoreactivity for Bax was seen in neurons and microglia of the hippocampal formation, and was elevated in the majority of AD cases as compared to control cases. Interestingly, 3 transitional cases, which had mild degeneration changes, exhibited relatively high levels of Bax immunoreactivity. Most Bax-positive neurons showed either TdT-labeled nuclei or Bcl-2 immunoreactivity. Although Bax immunoreactivity was detected within most early tangle-bearing neurons, many Bax-positive neurons did not colocalize with later-stage tangle-bearing neurons. In regions containing relatively few tangles in mild AD brains, many TdT-labeled neurons were immunolabeled with Bax antibody and most of them lacked evidence of neurofibrillary changes. These findings suggest that Bax may contribute to neuronal cell death in AD. Furthermore, DNA damage and the upregulation of Bax appear to precede tangle formation or may represent an alternative pathway of cell death in AD.

Clinicopathological features of bladder cancer associated with chronic exposure to arsenic

A high incidence of bladder cancer has been documented in an area of chronic arsenic (As) exposure. This study investigates the characteristics of As-associated (n = 49) and other (n = 64) bladder cancers. A higher histological grading was observed for the As-exposed tumours (P = 0.04), but no other difference in pathobiological features or prognosis was found between the two groups.

Plaque biogenesis in brain aging and Alzheimer's disease. I. Progressive changes in phosphorylation states of paired helical filaments and neurofilaments

Paired helical filament (PHF)/tau immunoreactive dystrophic neurites are a common pathological feature in the brain of patients with Alzheimer's disease. Recent studies suggest that swollen neurofilament-immunoreactive neurites are also present in senile plaques. In the present study, we investigated whether PHF/tau-positive dystrophic neurites are located in all subtypes of plaques and whether swollen neurofilament-immunoreactive neurites are hyper-phosphorylated, using a battery of antibodies to PHF/tau, neurofilament, and beta-amyloid protein. PHF/tau-positive dystrophic neurites were present in and around nearly all subtypes of plaques, including small amyloid deposits, diffuse plaques, and perivascular plaques in the hippocampal formation of Alzheimer brain. The earlier changes were detectable with AT8 antibody and later changes with PHF-1 antibody. Plaque-associated PHF/tau-positive dystrophic neurites were rare or absent in the hippocampal formation of normal aged brain. Swollen neurofilament-positive neurites appeared to be hyper-phosphorylated in Alzheimer's disease and to a lesser degree in aged control brains. Neurites that contained hyper-phosphorylated tau as well as neurofilament were strongly argentophilic because both populations of dystrophic neurites stained with silver stains. Swollen neurofilament-positive plaque-associated neurites were often present in the absence of PHF/tau-positive plaque-associated dystrophic neurites. These data suggest that PHF/tau-positive dystrophic neurites are a common component of all subtypes of plaques in Alzheimer brain and neurofilament protein in swollen neurites, like tau protein, is hyper-phosphorylated. Hyper-phosphorylated neurofilaments in plaque-associated neurites may represent one of the earliest cytoskeletal changes in vulnerable neurons in Alzheimer's disease and aged control brains.

Mechanisms of neuronal death in Alzheimer's disease

Recent data in cell culture has shown that brain neurons are particularly vulnerable to degeneration by apoptosis. Further the inducers that activate the program (e.g. beta-amyloid, oxidatative damage, low energy metabolism) correspond to conditions present in the Alzheimer's disease (AD) brain. This suggests the possibility that apoptosis may be one of the mechanisms contributing to neuronal loss in this disease. Indeed, some neurons in vulnerable regions of the AD brain show evidence of DNA damage, nuclear apoptotic bodies, chromatin condensation, and the induction of select genes characteristic of apoptosis in cell culture and animal models. This suggests the existence of apoptosis in the AD brain, a hypothesis also consistent with evolving research in one of the regulatory functions of the presenilin genes. On the other hand, DNA damage is present in the majority of neurons in vulnerable regions in early and mild cases. In most tissues, cells in fully activated apoptosis degenerate and are removed within hours to days and thus it seems all DNA damage is unlikely to signify terminal apoptosis. The presence of extensive DNA damage suggests an acceleration of damage, faulty repair process, loss of protective mechanisms, or an activation and arrest of aspects of the apoptotic program. DNA damage is unlikely to be an artifact of postmortem delay or agonal state. The existence of protective mechanisms for neurons may exist as these cells are nondividing and essential. In this context it is interesting that Bcl-2 is upregulated in most neurons with DNA damage. Further, at least one DNA repair enzyme is also upregulated. Thus it appears as if neurons are in a struggle between degeneration and repair. As research advances it is critical to reduce the stimuli that cause the neuronal damage and discover the key intervention points to assist neurons in the repair processes.

Gene expression of Alzheimer-associated presenilin-2 in the frontal cortex of Alzheimer and aged control brain

The presenilin-2 (PS2) gene expression pattern in Alzheimer's disease (AD) and control brains was examined using nonradioactive in situ hybridization. Message for PS2 was primarily detectable in neurons, particularly in somal cytoplasm. Intense staining signal was most commonly found in large pyramidal neurons, whereas moderate or faint staining was usually present in smaller neurons. The pattern of PS2 gene expression exhibited a laminar distribution profile in the frontal cortex. A small subset of tangle-bearing neurons exhibited PS2 hybridization signal in AD. PS2 mRNA expression appeared correlated to a high degree with lipofuscin autofluorescence in a large subset of neurons.

DNA damage and apoptosis in Alzheimer's disease: colocalization with c-Jun immunoreactivity, relationship to brain area, and effect of postmortem delay

Many neurons in Alzheimer's disease (AD) exhibit terminal deoxynucleotidyl transferase (TdT) labeling for DNA strand breaks with a distribution suggestive of apoptosis. We have shown previously that immunoreactivity for c-Jun is elevated in AD and found in association with neuronal pathology. In addition, cultured neurons undergoing beta-amyloid-mediated apoptosis exhibit a selective and prolonged induction of c-Jun. Consequently, we conducted double-labeling experiments to examine whether c-Jun is associated with DNA strand breaks in AD tissue; we observed a strong colocalization between these markers. As would be predicted based on the distribution of AD pathology, we also found that TdT labeling was prominent in the entorhinal cortex, but absent or at very low levels in cerebellum. Furthermore, we confirmed that postmortem delay (PMD) does not affect TdT labeling within the limits used for tissue used in this study. However, in contrast to previous studies, we report an increase in TdT labeling with more extended PMDs. Finally, gel electrophoresis of genomic DNA isolated from AD and control cases failed to reveal evidence for either an apoptotic or a necrotic mechanism of cell death in AD, possibly because of a low number of cells actually undergoing cell death at any given time. Our findings support the hypothesis that DNA damage labeled using TdT reflects neuronal vulnerability and cell loss associated with AD pathology, and that at least a portion of the cells labeled with this technique is undergoing apoptosis. Furthermore, in agreement with in vitro findings, these results suggest a relationship between the expression of c-Jun and neuronal risk and/or cell death in AD.

Up-regulation of Bcl-2 is associated with neuronal DNA damage in Alzheimer's disease

Cell death and neurofibrillary tangle formation are prominent features of Alzheimer's disease (AD). It has been suggested that DNA damage may reflect neuronal vulnerability. In this context, the Ced homologue Bcl-2 is able to repress a number of cell death programs. Recently we found both numerous nuclei exhibiting DNA damage within neurons in the AD brain and increases in Bcl-2 immunoreactivity. In this study, we examined the relationship between Bcl-2 expression and nuclear DNA damage or tangle formation. Nuclei exhibiting DNA damage were associated with an up-regulation of Bcl-2 expression, whereas tangle-bearing neurons were associated with a down-regulation of Bcl-2 expression.

Immunohistochemical evidence for apoptosis in Alzheimer's disease

Recently, in vitro studies conducted in our laboratory and others have suggested that apoptosis may have a role in the neuronal cell death associated with Alzheimer's disease (AD). To evaluate this hypothesis, the hippocampi and entorhinal cortices of AD, aged control, and surgical biopsy tissue were examined using the ApopTag system for the detection of DNA fragmentation and DNA strains to reveal nuclear morphology. Numerous neuronal nuclei displaying distinct morphological characteristics of apoptosis were present within tangle-bearing neurons as well as non-tangle-bearing neurons in AD brain, whereas few or no such nuclei were detected in control brain. Our in vivo results support the hypothesis that apoptosis may be one mechanism leading neuronal cell death in AD.

Early phosphorylation of tau in Alzheimer's disease occurs at Ser-202 and is preferentially located within neurites

Within the neurofibrillary tangles (NFTs) and dystrophic neurites (DNs) of Alzheimer's disease (AD), the cytoskeletal protein tau is abnormally hyperphosphorylated. In this study we evaluate the phosphorylation of specific residues on tau within different phases of the formation of NFTs. Two monoclonal antibodies, AT8 and PHF-1, were used to selectively recognize phosphorylated Ser-202 and Ser-396 of PHF-tau protein, respectively. We found that abnormal phosphorylation of tau appears to occur first at Ser-202 in DNs, then at Ser-202 in the soma and finally at Ser-396 in DNs and NFTs. These results suggest that abnormal phosphorylation at Ser-202 of PHF-tau in DNs represents one of the earliest neuropathological changes within the neurites of vulnerable neurons and may have a pivotal role in the initial pathogenesis of AD.

A comparison of enzyme-linked immunosorbent assay (ELISA) with sperm immobilization test (SIT) in detection of antisperm antibodies in sera of infertile women

In the present study, an enzyme-linked immunosorbent assay (ELISA) for antisperm antibodies was compared with a traditional standard sperm immobilization test (SIT) in sera from 158 infertile women in order to evaluate their clinical usefulness for various causes of infertility. Ten pregnant and unmarried women were used as the control group. There was a higher incidence rate by ELISA (13.9%) compared with that by SIT (10.1%) after examination of overall samples, although the difference was not statistically significant. The unexplained infertility group exhibited the highest incidence among the various causes of infertility in both of these two methods. Fifteen (93.8%) of 16 patients with positive SIT showed positive reaction in ELISA method, indicating that a close correlation exists between the two methods. The positive predictive value (54.5%) of ELISA was significantly (p < 0.05) lower than that (87.5%) of SIT, as evaluated with the results of postcoital test (PCT) performed at periovulatory phase. This suggests that the ELISA method for antisperm antibodies is less specific than SIT in view of the PCT results. Nevertheless, no fresh sperms are not required for the ELISA examination. Thus, it seems that the ELISA method may provide a convenient and practical means for mass screening in detecting antisperm antibodies in clinical practice.

MRI demonstration of peritoneal implants

The magnetic resonance imaging (MRI) findings of 12 proven cases of peritoneal implants, mainly carcinomatosis, were reviewed for evidence of peritoneal seedings. The seeded sites include the pouch of Douglas, the ileocecal and retrocecal regions, the right and left paracolic gutters, Morison's pouch, the right subdiaphragmatic parietal peritoneum, the greater and lesser omentum, the gastrocolic, gastrosplenic, and phrenicocolic ligaments, the small bowel mesentery, the sigmoid and transverse mesocolons, and the small and large bowel walls. Sizes varied from less than 1 cm to omental cake and bulky tumors. The findings include linear or tiny nodular infiltrations of the omentum and subperitoneal fat (ligamentous, mesenteric, and mesocolic), focal or segmental wall thickenings, loss of unilateral colonic haustration with sacculation on the contralateral side, and nodular soft tissue masses along different locations of the peritoneal surfaces. Air was introduced via an antegrade or retrograde method to act as a gastrointestinal contrast agent and was found to be useful for delineating the seedings. As is true with computed tomography scan, miliary implants are also not detectable with MRI. The sensitivity and specificity of MRI in detecting peritoneal implants remain to be determined.

Subpopulations of dystrophic neurites [correction of neuritis] in Alzheimer's brain with distinct immunocytochemical and argentophilic characteristics

Using two monoclonal antibodies, tau-1 and PHF-1, and a sequential staining method combining double-labeling immunofluorescence and Bielschowsky silver staining, we have demonstrated the presence of two populations of dystrophic neurites (DNs) with distinct immunocytochemical and argentophilic characteristics. Tau-1 and PHF-1 immunoreactivity were co-localized in many DNs. However, approximately 20% of the DNs were immunoreactive for PHF-1 only. PHF-1 single-labeled DNs were not visible or very weak with Bielschowsky silver stain. Of DNs continuous with neurofibrillary tangles (NFTs), tau-1/PHF-1 double-labeled DNs were continuous with intracellular NFTs only, while PHF-1 single-labeled DNs were continuous with extracellular NFTs only. Furthermore, the population of DNs that cluster around extracellular NFTs is different from those that cluster around or within senile plaques. The combined use of tau-1 and PHF-1 immunocytochemistry may provide a more accurate indication of the number of extracellular DNs and extracellular NFTs, which may aid in the diagnosis of severe and advanced AD cases.

Neuritic involvement within bFGF immunopositive plaques of Alzheimer's disease

As early as 1928, Cajal suggested that plaques contain a trophic substance which attracts neurites. Recently, basic fibroblast growth factor (bFGF) levels were shown to be elevated in Alzheimer's disease (AD) and localized to plaques and neurofibrillary tangles. We sought to clarify the subtype of plaques which contain bFGF and provide more detail on bFGFs neuronal and vascular localization in normal aged brain, AD brain, and Down's syndrome (DS) brain. We combined double-labeling immunocytochemistry for bFGF with heparan sulfate glycosaminoglycans, beta-amyloid, and thioflavine fluorescence. In addition, the neuritic markers tau-1 and PHF-1 were combined with bFGF staining. Eleven AD, five nondemented controls, and four DS cases were examined. Most bFGF immunopositive plaques contained numerous dystrophic fibers, indicating they were of the neuritic subtype. We also detected a variety of bFGF-positive cells, including hilar, dentate granule, pyramidal, and stellate neurons, as well as astrocytes. The basement membrane of large and small arterioles also contained bFGF. bFGF immunoreactivity within neurons, astrocytes and the vasculature was increased in AD cases relative to controls. Immunoreactivity within the DS cases was intermediate. These results suggest that bFGF is up-regulated in AD and support the hypothesis that bFGF may attract neurites into plaques. Alternatively, an injured neurite may induce bFGF production by responding glia, resulting in further neuritic attraction.

Beta-amyloid accumulation in aged canine brain: a model of early plaque formation in Alzheimer's disease

We characterized eight aged beagles (maintained from birth in a laboratory colony) and one black Labrador using Bielschowsky's, thioflavine S, and Congo red staining, and antibodies to the beta-amyloid peptide, dystrophic neurites, and other plaque components. All plaques within these canine brains were of the diffuse subtype and were neither thioflavine S- nor Congo red-positive. The majority of plaques in the entorhinal cortex contained numerous neurons within them while plaques in the dentate gyrus did not. beta-Amyloid immunoreactivity was also present within select neurons and neuronal processes and was detected as a diffuse linear zone corresponding to the terminal fields of the perforant path. There was no significant correlation between extent of beta-amyloid accumulation and neuron number in entorhinal cortex. Neither tau-1, PHF-1, nor SMI-31-immunostaining revealed dystrophic fibers, confirming the classification of these plaques as diffuse. Canine plaques did not appear to contain bFGF- or HS-positive immunostaining. This may explain why neuritic involvement was not detected within these canine plaques. It is possible that the beta-amyloid within the canine brain has a unique primary structure or may not be in an assembly state that adversely affects neurons.

Identification and distribution of axonal dystrophic neurites in Alzheimer's disease

Dystrophic neurites (DNs) are one of the neuropathological characteristics of Alzheimer's disease (AD). Previously, it has been suggested that tau-immunoreactive DNs are of dendritic origin and that axonal and dendritic dystrophic neurites are morphologically indistinguishable. In the present study, two monoclonal antibodies, tau-1 and PHF-1, were used to examine sections of the hippocampal formation from AD and normal aged brains. Both antibodies stained dendritic DNs as well as axonal DNs. Axonal DNs were clearly seen in axonal fiber tracts, white matter and hippocampal terminal regions. Axonal DNs arising from neurofibrillary tangles were easily detected in CA3 and CA1. The morphological appearance of axonal DNs varied with the neuron type from which it originated. The most distinctive feature of tau-1 or PHF-1 immunostained axonal DNs was their uneven contour, alternating swollen and shrunken segments and short rod or cone shaped fragments. In contrast, dendritic dystrophic neurites are thicker and more tortuous. It appears that while DNs are both dendritic and axonal in origin, axonal DNs are more prevalent and widespread in the AD brain than previously realized and may represent one of the main pathological lesions in AD.