[Evaluation of cytarabine-induced apoptosis in leukemic cell lines; utility of annexin V method]

Apoptosis is a morphologically and biochemically distinct form of cell death that occurs under a variety of physiological and pathological conditions. In the present study, using leukemic cell lines, time course of cytarabine-induced apoptosis was examined morphologically, using annexin V method, TUNEL method and fluorometric assay for caspase-3 activity. Morphological changes characteristic of apoptosis were observed in U937 and HL60 cells after 4-hour incubation with cytarabine and progressively evident until 48-hour incubation, but rarely found in K562 cells. In annexin V method and assay for caspase-3 activity, changes accompanied by apoptosis could also be detected at 4-hour incubation with cytarabine, but in TUNEL method, they were not found until 24-hour incubation. The advantage of annexin V method which detects phosphatidylserine emerging on cell surface during the early course of apoptosis included simplicity and rapidity of the procedure and short time requirement for apoptosis to appear after incubation with cytarabine. Usefulness of annexin V method in a study of clinical samples was discussed.

Non-traumatic acute paraplegia associated with cervical disc herniation: a case report

BACKGROUND

Acute paraplegia attributable to disc herniation is known to occur most frequently at the thoracic level. We report a rare case of non-traumatic acute paraplegia caused by disc herniation at the cervical level. Preoperative magnetic resonance imaging (MRI) of the present case demonstrated a spinal cord lesion as a cause of paraplegia. Although this symptom is believed to disappear rapidly after surgical treatment, there have been a few reported cases with poor neurologic recovery and permanent deficits.

CASE DESCRIPTION

A 61-year-old female with a history of minor neck pain suffered from non-traumatic acute paraplegia attributable to cervical disc herniation. She underwent emergency surgery consisting of vertebrectomy, removal of herniated discs, and anterior fusion. Postoperative neurologic improvement was slow due to the cervical spinal cord lesion at the central portion of the cord, which was detected by the preoperative and postoperative MRIs.

CONCLUSION

We emphasize that the MRI study is crucial for the management of patients with acute neck pain associated with cervical canal stenosis. Surgical treatment should not be delayed to avoid permanent neurologic deficits. Anterior decompression with vertebrectomy is recommended to decompress the injured spinal cord in the narrow cervical spinal canal; however, a cord lesion detected by MRI may indicate an incomplete surgical outcome.

Possible influences of Staphylococcus aureus on atopic dermatitis-- the colonizing features and the effects of staphylococcal enterotoxins

BACKGROUND

Heavy colonization of atopic dermatitis (AD) with Staphylococcus aureus is well documented. This phenomenon suggests that S. aureus in AD lesions influences the disease processes of AD.

OBJECTIVE

We describe the importance of the presence of S. aureus and staphylococcal enterotoxins A and B (SEA, SEB) in AD lesions.

METHODS

We investigated the colonizing features of S. aureus in AD lesions using electron microscopy, the distribution of SEB in the eczematous skin of AD using immunofluorescence, the effects of SEA and SEB on normal human epidermal keratinocytes in organ culture, and the presence of specific IgE antibodies to SEA and/or SEB in serum of AD patients by enzyme immunoassay.

RESULTS

S. aureus in AD lesions colonized on and in the horny layers of the eczematous skin. SEB produced by S. aureus was distributed mainly on the dermal-infiltrated cells, especially on eosinophils. SEA and SEB stimulated expression of ICAM-1 and HLA-DR in normal human keratinocytes. More than half of the AD patients in the present study had specific IgE antibodies to SEA and/or SEB in their serum.

CONCLUSION

S. aureus and SEs have important roles in the exacerbation and prolongation of AD.

TAK-778, a novel synthetic 3-benzothiepin derivative, promotes chondrogenesis in vitro and in vivo

TAK-778, a novel synthetic 3-benzothiepin derivative, stimulates the formation of cartilaginous nodules in mouse chondroprogenitor-like ATDC5 cells in vitro in association with upregulation of the gene expression of transforming growth factor-beta(2), but not bone morphogenetic protein-4 and insulin-like growth factor-I. One-shot injection of the TAK-778-containing sustained-release microcapsules accelerated the repair process of the full thickness defects of articular cartilage in rabbit knees. Our in vitro and in vivo results indicate that TAK-778 may be a therapeutically useful synthetic agent for articular cartilage repair.

Serum lipids status in patients with diabetic uremia on 10 years of maintenance hemodialysis

BACKGROUND

Dyslipidemia in patients with diabetic uremic patients remains unclear. We previously reported that lipid abnormalities in diabetic uremia on short-term (3 to 28 months) hemodialysis therapy were more severe than those in nondiabetic uremic patients. The object of this study is to investigate the serum lipid profiles in diabetic uremic patients on 10 years of maintenance hemodialysis treatment.

METHODS

Thirty diabetic uremic subjects and 40 age-matched nondiabetic subjects on long-term hemodialysis therapy were selected, and their clinical characteristics and serum concentrations of lipids, apolipoproteins, lecithin cholesterol acyltransferase (LCAT) activity, and apolipoprotein (apo) E phenotype were evaluated.

RESULTS

Patients with diabetic uremia had a higher prevalence of macrovascular complications, including ischemic heart diseases and cerebrovascular diseases. The mean levels of serum total cholesterol, triglyceride, and high-density lipoprotein cholesterol remained normal. Nondiabetic uremic patients exhibited a reduction in serum apo A-1 serum apo A-2, serum apo C-2, and LCAT activity and an increase in serum Apo C-3. Diabetic uremic patients showed a further reduction in serum apo A-1, serum apo A-2, serum apo E, and LCAT activity. Frequencies of apo E isoforms were not significantly different between two groups of uremic patients.

CONCLUSIONS

These results clearly indicate that lipid abnormalities in diabetic uremic patients on long-term hemodialysis therapy are more enhanced than those in nondiabetic uremic patients, suggesting that diabetic hemodialyzed patients are more prone to increase the individual risk for accelerated atherosclerosis to cause a higher incidence of cardiovascular diseases.

Significance of para-aortic lymph node dissection in advanced gastric cancer

BACKGROUND/AIMS

Since surgical results in advanced gastric cancer remain poor and para-aortic lymph node dissection may contribute to survival, it is useful to determine the significance of para-aortic lymph node dissection.

METHODOLOGY

Para-aortic lymph node dissection was provisionally indicated for patients with invasion depth deeper than the subserosal layer. Clinicopathologic variables were retrospectively analyzed using univariate analysis and multivariate analysis to predict para-aortic lymph node metastasis. Similarly, they were analyzed using univariate analysis and the Cox's proportional hazards regression model to estimate the prognostic factor in 120 patients who underwent para-aortic lymph node dissection. Surgical results and post-operative complications were compared between para-aortic lymph node dissection and D2 dissection.

RESULTS

Univariate analysis revealed that the mean diameter, the degree of lymph node metastasis, and the invasion depth were significant predictors of para-aortic lymph node metastasis. Multivariate analysis showed that n2 was the only independent predictive factor as to para-aortic lymph node metastasis. Univariate analysis revealed tumor site, tumor diameter, lymph node metastasis, number of positive lymph nodes, INF, and stage were significantly associated with 5-year survival. The Cox's proportional hazards regression model showed that the number of positive lymph nodes and the number of positive para-aortic lymph nodes were independent prognostic factors. Patients with < or = 10 positive lymph nodes in any stage or < or = 3 positive para-aortic lymph nodes in stage IVb had significantly better surgical results. Surgical results for patients who underwent para-aortic lymph node dissection with n2 or invasion depth deeper than the exposed serosa were significantly higher than those in D2. As to post-operative complications, pancreatic fistula and respiratory complications were significantly frequent after para-aortic lymph node dissection.

CONCLUSIONS

n2 is helpful in predicting para-aortic lymph node metastasis. Whereas, post-operative morbidity such as pancreatic fistula and respiratory complications after para-aortic lymph node dissection were significantly higher, they were controllable. Para-aortic lymph node dissection should be indicated in advanced gastric cancer patients in which lymph node metastasis is over n2 or invasion depth is deeper than the exposed serosa. But the number of positive para-aortic lymph nodes must be less than three.

Molecular remission in adult T cell leukemia after autologous CD34+ peripheral blood stem cell transplantation

This report describes a patient with acute-type adult T cell leukemia/lymphoma (ATLL) successfully treated by autologous CD34+ peripheral blood stem cell transplantation after fractionated total body irradiation and high-dose cytarabine and cyclophosphamide. A newly established inverse polymerase chain reaction method was used to demonstrate the disappearance of ATLL clonal cells. The patient achieved a sustained molecular remission after transplantation, but died from opportunistic infection 4 months after transplantation. Thus, autologous CD34+ peripheral blood stem cell transplantation is promising for this type of malignancy. However, a prudent clinical attitude toward immunological fragility after transplantation is needed for better outcome.

Two cases of aorto-gastrointestinal fistula

We report two cases of aorto-gastrointestinal fistula. Case 1, a 60-year-old man, suffered from repeat hematemesis. He was preoperatively diagnosed as aortoesophageal fistula with thoracic aortic aneurysm and was successfully treated by graft replacement of the aneurysm. Case 2, a 73-year-old man, presented with massive gastrointestinal bleeding, yet repeat endoscopical examination did not reveal the origin of the bleeding. He died of catastrophic hematochezia. The pathological findings at autopsy revealed an aortoduodenal fistula. These two cases suggested the importance to consider an aorto-gastrointestinal fistula in the differential diagnosis of patients presenting gastrointestinal hemorrhage.

Craniocervical junction synovial cyst associated with atlanto-axial dislocation--case report

A 51-year-old female presented with a rare case of synovial cyst at the cruciate ligament of the odontoid process associated with atlanto-axial dislocation, manifesting as a history of headache and numbness in her left extremities for 5 months, and progressive motor weakness of her left leg. Neuroimaging studies revealed a small cystic lesion behind the dens, which severely compressed the upper cervical cord, and atlanto-axial dislocation. The cyst was successfully removed via the transcondylar approach. C-1 laminectomy and foramen magnum decompression were also performed. Posterior craniocervical fusion was carried out to stabilize the atlanto-axial dislocation. The cyst contained mucinous material. Histological examination detected synovial cells lining the fibrocartilaginous capsule. Synovial cysts of this region do not have typical symptoms or characteristic radiographic features. Careful preoperative evaluation of the symptoms and a less invasive strategy for removal of the cyst are recommended.

Noggin and bone morphogenetic protein-4 coordinately regulate the progression of chondrogenic differentiation in mouse clonal EC cells, ATDC5

Here we report the gene expression and regulation and the function of noggin in clonal mouse chondrogenic EC cells, ATDC5. In ATDC5 cells, the expression of Noggin mRNA increased in parallel with the progression of chondrogenic differentiation. The treatment with conditioned medium of noggin-transfected COS-7 cells decreased the levels of type II and type X collagen gene transcripts of differentiated ATDC5 cells in a dose-dependent manner, and this inhibitory action was reversed by exogenously administered BMP-4 in a dose-dependent manner. The steady-state level of noggin gene transcripts was markedly upregulated by exogenously administered BMP-4 in time- and dose-dependent manners. Furthermore, this stimulatory effect of BMP-4 was attenuated by treatment with actinomycin D, but not with cycloheximide. These results indicate that noggin and BMP-4 coordinately regulate the progression of chondrogenic differentiation in ATDC5 cells.

The effect of feeding carrots on immunoglobulin E production and anaphylactic response in mice

Carrot juice was administered orally to BALB/c mice immunized intraperitoneally with dinitrophenylated (DNP)-OVA for about 1 month. The titers of DNP-specific IgE, DNP-specific IgG, and the levels of total IgE in mouse sera were determined. The DNP-specific IgE production by mice fed carrot juice was significantly inhibited. On the other hand, the DNP-specific IgG production and the level of total IgE in mice fed carrot juice were not significantly different from those in control mice. We also examined the effect of feeding carrots on immediate-type hypersensitivity. One hour after antigen stimulation, the ears of mice fed carrots swelled less than those of control mice. Furthermore, the rise in serum histamine in the mice fed carrots under active systemic anaphylaxis was lower than in controls. We then examined the pattern of cytokine production by spleen cells from mice followed by restimulation with DNP-OVA in vitro. The spleen cells from the mice fed carrots produced more interferon-gamma than those from the control group. In contrast, the spleen cells from the mice fed carrots produced less interleukin-4 than those from the control group. Furthermore, the interleukin-12 production of the spleen cells from mice fed carrots was also higher than that of the control group. These findings suggest that feeding carrots improves the helper T cell (Th)1/Th2 balance, inhibiting specific IgE production and antigen-induced anaphylactic response.

Vascular changes in white matter lesions of Alzheimer's disease

The pathogenesis of white matter lesions observed in Alzheimer's disease (AD) is not completely clear. We tested the hypothesis that white matter lesions are correlated with medullary artery sclerosis rather than with amyloid angiopathy. A total of 57 brains were examined, including 39 derived from patients with AD and 13 from patients with Binswanger's disease (BD) along with 5 from non-neurological patients. Moderate or severe amyloid deposits in the meningocortical segment were observed in 32 out of 39 AD patients (82.1%), and in 2 out of 13 BD patients (15.4%). These deposits were not observed in the white matter segment, except for 2 patients with AD. The BD patients invariably had marked white matter lesions and fibrohyalinosis in the medullary arteries, with a mean sclerotic ratio of 48.1%. In contrast, the AD patients had mild or moderate white matter lesions and a sclerotic ratio of 37.9%, which was significantly greater than the controls. The scores for white matter lesions were correlated with the sclerotic ratio of the medullary arteries, but not with the ages of onset or the scores for amyloid angiopathy. Although amyloid angiopathy is an independent risk of white matter lesions, its role is limited in the pathogenesis of those associated with AD. Wall thickening of the medullary arteries, likely due to fibrohyalinosis, is closely correlated with the white matter lesions in AD, thus indicating a heterogeneity in its etiology.

Cologastric fistula and colonic perforation as a complication of percutaneous endoscopic gastrostomy

Cologastric fistula has rarely been reported as a complication of percutaneous endoscopic gastrostomy (PEG). We encountered a patient in whom this problem went unrecognized for 2 years. After the initial PEG tube was changed, the second PEG tube was advanced into the colon, causing severe diarrhea. When a third PEG tube was inserted, acute peritonitis occurred because of colonic perforation. We discuss the mechanism of this complication and technical points related to its prevention.

Simultaneous quantitative determination of cilostazol and its metabolites in human plasma by high-performance liquid chromatography

A high-performance liquid chromatographic (HPLC) method for the simultaneous determination of cilostazol, a quinolinone derivative, and its known metabolites OPC-13015, OPC-13213, OPC-13217, OPC-13366, OPC-13269, OPC-13326 and OPC-13388 in human plasma was developed and validated. Cilostazol, its metabolites and two internal standards, OPC-3930 and OPC-13112, were extracted from human plasma by a combination of liquid-liquid and liquid-solid phase extractions, with combined organic solvents of n-butanol, methanol, chloroform, methyl-tert.-butyl ether, and a Sep-Pak silica column. The combined extract was then evaporated and the residue was reconstituted in ammonium acetate buffer (pH 6.5). The reconstituted solution was injected onto a HPLC system and was subjected to reversed-phase HPLC on a 5 microm ODS-80TM column to obtain quality chromatograph and good peak resolution. A gradient mobile phase with different percentages of acetonitrile in acetate buffer (pH 6.5) was used for the resolution of analytes. Cilostazol, its metabolites and the two internal standards were well separated at baseline from each other with resolution factor being 74 and 138. This HPLC method was demonstrated to be specific for all analytes of interest with no significant interference from the endogenous substances of human plasma. The lower limit of quantitation was 20 ng/ml for cilostazol and all metabolites. The method was validated initially for an extended linear range of 20-600 ng/ml for all metabolites and cilostazol, and has been revised later for a linear range of 20-1200 ng/ml for cilostazol and two major and active metabolites OPC-13015 and OPC-13213. The overall accuracy (relative recovery) of this method was established to be 98.5% to 104.9% for analytes with overall precision (CV) being 1.5% to 9.0%. The long-term stability of clinical plasma samples was established for at least one year at -20 degrees C. Two internal standards of OPC-3930 and OPC-13112 were evaluated and validated. However, the data indicated that there was no significant difference for all accuracy and precision obtained by using either OPC-3930 or OPC-13112. OPC-3930 was chosen as the internal standard for the analysis of plasma samples from clinical studies due to its shorter retention time. During the validation standard curves had correlation coefficients greater than or equal to 0.998 for cilostazol and the seven metabolites. These data clearly demonstrate the reliability and reproducibility of the method.

Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloid leukemia

Internal tandem duplication of the FLT3 gene and point mutations of the N-RAS gene are the most frequent somatic mutations causing aberrant signal-transduction in acute myeloid leukemia (AML). However, their prognostic importance is unclear. In this study, their prognostic significance was analyzed in 201 newly diagnosed patients with de novo AML except acute promyelocytic leukemia. Three patients had mutations in both genes, 43 had only the FLT3 gene mutation, 25 had only the N-RAS gene mutation, and 130 had neither. These mutations seemed to occur independently. Both mutations were related to high peripheral white blood cell counts, and the FLT3 gene mutation was infrequently observed in the French-American-British (FAB)-M2 type. AML cases with wild FLT3/mutant N-RAS had a lower complete remission (CR) rate than those with wild FLT3/wild N-RAS, whereas the presence of mutant FLT3 did not affect the CR rate. Univariate analysis showed that unfavorable prognostic factors for overall survival were age 60 years or older (P =.0002), cytogenetic data (P =.002), FAB types other than M2 (P =.002), leukocytosis over 100 +/- 10(9)/L (P =.003), and the FLT3 gene mutation (P =.004). However, the N-RAS gene mutation was only a marginal prognostic factor (P =.06). For the subjects under 60 years old, multivariate analysis showed that the FLT3 gene mutation was the strongest prognostic factor (P =.008) for overall survival. The FLT3 gene mutation, whose presence is detectable only by genomic polymerase chain reaction amplification and gel electrophoresis, might serve as an important molecular marker to predict the prognosis of patients with AML.

Cloning of cellulose synthase genes from Acetobacter xylinum JCM 7664: implication of a novel set of cellulose synthase genes

Three sets of cellulose synthase genes were cloned from a cellulose-producing bacterium Acetobacter xylinum JCM 7664. One set of genes (bcsAI/bcsBI/bcsCI/bcsDI) were highly conserved with the well-established type I genes in other strains of A. xylinum, while the other two (bcsABII-A, bcsABII-B) were homologous to the known type II (acsAII). Unexpectedly, they were immediately followed by a gene cluster of bcsX/bcsY/bcsCII/ORF569, likely forming an operon. Western blotting demonstrated that the BcsY protein accumulated in cells. Since BcsY showed striking similarities to a number of membrane-bound transacylases, it was hypothesized that the type II cellulose synthase produces acylated cellulose, which might be anchored on the cytoplasmic membrane. An insertion sequence of IS1380-type was found just upstream of the one type II gene (bcsABII-B), suggestive of nonfunctioning.

Indian hedgehog in the late-phase differentiation in mouse chondrogenic EC cells, ATDC5: upregulation of type X collagen and osteoprotegerin ligand mRNAs

Endochondral bone formation includes a cascade of cellular events such as proliferation, maturation, hypertrophic conversion and calcification of chondrocytes and the cartilage replacement by bone. During these processes, hypertrophic conversion and calcification of chondrocytes (the late-phase differentiation) is a crucial process of chondrogenic differentiation. Indian hedgehog (Ihh), a secreted protein expressed in early hypertrophic chondrocytes, is thought to be involved in regulation of hypertrophic conversion via a feedback loop through the perichondrium. In the present study, we showed by Northern analysis and in situ hybridization that Smoothened (Smo), a key component in hedgehog signal transduction, was expressed in chondrocytes in both adult mice and mouse embryos at 16 days post-coitum in vivo, suggesting that Ihh directly acts on chondrocytes. We previously reported that Ihh, Patched and Smo were all expressed in differentiated ATDC5 cells. Exogenously administered mouse recombinant N-terminal protein of Ihh (mrIhh-N) upregulated the gene expression of type X collagen, a phenotypic marker of hypertrophic chondrocytes, as well as osteoprotegerin ligand (OPGL), a potent stimulator of osteoclastogenesis and osteoclast activity, while it did not modulate the expression of Ihh itself, bone morphogenetic protein (BMP)-4, BMP-6, transforming growth factor (TGF)-beta1 and TGF-beta2 in differentiated ATDC5 cells. Moreover, when added to the osteoclast cultures, mrIhh-N markedly stimulated the formation of resorption pits on dentine slices. Our data support the hypothesis that Ihh stimulated the late-phase chondrogenic differentiation in differentiated ATDC5 cells and upregulated the gene expression of OPGL in these cells.

Immunohistochemical localization of amyloid beta-protein with amino-terminal aspartate in the cerebral cortex of patients with Alzheimer's disease

We investigated immunohistochemically the localization of amyloid beta-protein (Abeta) with amino-terminal aspartate (N1[D]) in brains of patients with Alzheimer's disease, diffuse Lewy body disease and Down's syndrome. A monoclonal antibody, 4G8, which recognizes the middle portion of Abeta, was used as a reference antibody to label the total Abeta deposits. Double staining with anti-Abeta(N1[D]) and 4G8 revealed that Abeta deposits in the subiculum and the neocortical deep layers often lacked N1[D] immunoreactivity, indicating N-terminal truncation of Abeta in these deposits. Abeta deposits in the neocortical superficial layers and the presubicular parvopyramidal layer always contained Abeta with N1[D]. Such regional as well as laminar differences in the distribution of Abeta beginning at N1[D] suggest that some local factors influence N-terminal processing of Abeta deposited in the brain.

Is the face and neck pattern of atopic dermatitis in Japan a special variant?

BACKGROUND

Adult atopic dermatitis (AD) with severe and refractory eruptions on the face, neck, and upper trunk, although quite rare in western countries, has increased in Japan.

OBJECTIVE

We have tried to clarify the possible causative factors for this particular type of AD, predominantly seen in Japan.

METHODS

Eighty-seven AD patients (37 men and 50 women) who had severe and refractory facial and neck lesions were patch tested with topical medicaments, cosmetics, and skin-management products.

RESULTS

Thirty-seven (42. 5%) patients showed positive reactions to more than one of those products: 14 patients to shampoo, rinse, or soap; 11 to topical nonsteroidal anti-inflammatory agents (NSAIDs); 7 to cosmetics; and 6 to corticosteroids.

CONCLUSION

We believe that topical NSAIDs, (which are often prescribed for the treatment of AD in Japan and rarely used for the treatment of eczamatous skin disorders in western countries), as well as common detergents, play important roles in the increased prevalence of AD patients with severe and refractory lesions on the face, neck, and upper trunk in Japan.

Cloning of a novel gene specifically expressed in clonal mouse chondroprogenitor-like EC cells, ATDC5

We cloned a full-length cDNA encoding a novel mouse protein, A-C2, by differential display method using mouse embryonic fibroblast C3H10T1/2 cells and mouse chondroprogenitor-like EC cells, ATDC5. The deduced amino acid sequence of A-C2 consisted of 106 amino acids with no significant homology to the sequences previously reported. Northern blot analysis showed two major bands of 2.1 and 1.8 kb sizes. Expression of A-C2 mRNA was exclusive to ATDC5 cells at their undifferentiated stage. None of ATDC5 cells at their differentiated stage and adult mice tissues examined expressed A-C2 gene.

Occurrence of the diffuse amyloid beta-protein (Abeta) deposits with numerous Abeta-containing glial cells in the cerebral cortex of patients with Alzheimer's disease

Diffuse amyloid beta-protein (Abeta) deposits with numerous glial cells containing C-terminal Abeta fragments occur in the cerebral cortex of patients with Alzheimer's disease. By using a panel of antibodies specific for various epitopes in the Abeta peptide, we have investigated the immunohistochemical nature of the diffuse Abeta deposits. The extracellular material contains Abeta with a C-terminus at residue valine40 (Abeta40) as well as residues alanine42/threonine43 (Abeta42). The N-termini include aspartate1, pyroglutamate3, and pyroglutamate11, with pyroglutamate3 being dominant. Microglia and astrocytes in and around these deposits contain intensely staining granules. Most of these granules are negative for antibodies to the N-terminally located sequences of Abeta. These include 6E10 (Abeta1-17), 6F/3D (Abeta8-17), and the N-terminal antibodies specific to aspartate1, pyroglutamate3, and pyroglutamate11. The C-termini of intraglial Abeta are comparable with those of the extracellular deposits. The microglia and astrocytes have quiescent morphology compared with those associated with senile plaques and other lesions such as ischemia. Complement activation in these deposits is not prominent and often below the sensitivity of immunohistochemical detection. Although factors which may cause this type of deposit remain unclear, lack of strong tissue responses suggests that these deposits are a very early stage of Abeta deposition. They were found only inconsistently and were absent in a number of cases examined in this study. Further analysis of these deposits might provide important clues regarding the accumulation and clearance of Abeta in Alzheimer's disease brain.