Global cognition and executive functions of older adults with type 1 diabetes mellitus without dementia

AIMS/INTRODUCTION

This study aimed to characterize the global cognition and executive functions of older adults with type 1 diabetes mellitus in comparison with type 2 diabetes mellitus.

MATERIALS AND METHODS

This study included 37 patients with type 1 diabetes mellitus aged ≥65 years and 37 age- and sex-matched patients with type 2 diabetes mellitus. Patients with dementia scoring <24 on the Mini-Mental State Examination were excluded. General cognition, memory, classic, and practical executive function were investigated.

RESULTS

Patients with type 1 diabetes mellitus demonstrated lower psychomotor speed scores on Trail Making Tests A and B (P < 0.001, P < 0.013) than those with type 2 diabetes mellitus. The dysexecutive syndrome behavioral assessment revealed similar results in patients with types 1 and 2 diabetes mellitus. The Wechsler Memory Scale-Revised verbal episodic memory and Montreal Cognitive Assessment Japanese version were similar in terms of general cognition, but worse delayed recall subset on the latter was associated with type 2 diabetes mellitus (P = 0.038). A worse Trail Making Test-A performance was associated with type 1 diabetes mellitus and age (P < 0.004, P < 0.029).

CONCLUSIONS

Executive function of psychomotor speed was worse in older outpatient adults without dementia with type 1 diabetes mellitus than in those with type 2 diabetes mellitus but with no significant differences in the comprehensive and practical behavioral assessment of dysexecutive syndrome. Patients with type 1 diabetes had more severely impaired executive function, whereas those with type 2 had greater impaired memory than executive function.

Odor identification score as an alternative method for early identification of amyloidogenesis in Alzheimer's disease

A simple screening test to identify the early stages of Alzheimer's disease (AD) is urgently needed. We investigated whether odor identification impairment can be used to differentiate between stages of the A/T/N classification (amyloid,  tau, neurodegeneration) in individuals with amnestic mild cognitive impairment or AD and in healthy controls. We collected data from 132 Japanese participants visiting the Toranomon Hospital dementia outpatient clinic. The odor identification scores correlated significantly with major neuropsychological scores, regardless of apolipoprotein E4 status, and with effective cerebrospinal fluid (CSF) biomarkers [amyloid β 42 (Aβ42) and the Aβ42/40 and phosphorylated Tau (p-Tau)/Aβ42 ratios] but not with ineffective biomarkers [Aβ40 and the p-Tau/total Tau ratio]. A weak positive correlation was observed between the corrected odor identification score (adjusted for age, sex, ApoE4 and MMSE), CSF Aβ42, and the Aβ42/40 ratio. The odor identification score demonstrated excellent discriminative power for the amyloidogenesis stage , according to the A/T/N classification, but was unsuitable for differentiating between the p-Tau accumulation and the neurodegeneration stages. After twelve odor species were analyzed, a version of the score comprising only four odors-India ink, wood, curry, and sweaty socks-proved highly effective in identifying AD amyloidogenesis, showing promise for the screening of preclinical AD.

Extracellular vesicle proteome unveils cathepsin B connection to Alzheimer's disease pathogenesis

Extracellular vesicles (EVs) are membrane vesicles that are released extracellularly and considered to be implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease. Here, CSF EVs of 16 ATN-classified cases were subjected to quantitative proteome analysis. In these CSF EVs, levels of 11 proteins were significantly altered during the ATN stage transitions (P < 0.05 and fold-change > 2.0). These proteins were thought to be associated with Alzheimer's disease pathogenesis and represent candidate biomarkers for pathogenic stage classification. Enzyme-linked immunosorbent assay analysis of CSF and plasma EVs revealed altered levels of cathepsin B (CatB) during the ATN transition (seven ATN groups in validation set, n = 136). The CSF and plasma EV CatB levels showed a negative correlation with CSF amyloid-β42 concentrations. This proteomic landscape of CSF EVs in ATN classifications can depict the molecular framework of Alzheimer's disease progression, and CatB may be considered a promising candidate biomarker and therapeutic target in Alzheimer's disease amyloid pathology.

Immobilization protocols following trapeziectomy for osteoarthritis of the thumb: 2 weeks versus 4 weeks

We compared the clinical outcomes of post-trapeziectomy protocols according to their duration. The main hypothesis was that there would be no significant difference in postoperative function whether immobilization duration was 2 or 4 weeks. The secondary hypotheses were that there would be no significant difference in postoperative pain, motion, or strength. 40 trapeziectomies were reviewed. Two weeks' postoperative commissural immobilization was systematic. Patients were then divided in two groups. For the first 20 patients (group I), immobilization stopped at 2 weeks. For the next 20 patients (group II) it was replaced by a splint for further 2 weeks. We compared mean pre- and post-operative (10-20 weeks) function (QuickDASH score), pain (visual analog scale - VAS), thumb opposition (Kapandji score) and strength (palmar pinch test) between the two groups. There was no significant difference between groups in postoperative values or in pre- to post-operative progression. The main hypothesis was confirmed: there was no significant difference in the postoperative function whether the immobilization was for 2 or 4 weeks. The secondary hypotheses regarding postoperative pain, motion and strength were also confirmed.

Designing a minimally-invasive, ultrasound-guided, percutaneous flexor tendon sheath lavage technique: a cadaver study

The goal of this study was to develop a minimally-invasive, ultrasound-guided percutaneous flexor tendon sheath lavage technique on cadaver model. Two catheters were inserted using ultrasound guidance at the proximal and distal ends of the tendon sheath in 20 fingers from cadaveric forearms. Percutaneous injection of a saline solution colored with methylene blue resulted in anterograde lavage of the flexor tendon sheath. The technique was successful in 13 out of 20 cases. The proximal catheter was in the correct position in 17 cases and the distal catheter was correctly positioned in 15 cases. The flexor tendons were continuous in all cases and had puncture wounds in 9 cases. Based on our study, this minimally-invasive, ultrasound-guided percutaneous lavage of the flexor tendon sheath was effective in 65% of cases and safe in 100% of cases in the index, middle and ring fingers. If this percutaneous lavage fails, it is always possible to switch to a conventional open technique.

Relevance of intraoperative ultrasound imaging for detecting foreign bodies in the hand: A series of 19 cases

Radiolucent foreign bodies of the hand are frequent and may lead to pain, infection, hematoma and/or migration. Their diagnosis and removal can be difficult. The goal of this study was to assess the usefulness of intraoperative ultrasound imaging for detecting translucent foreign bodies in the hand to facilitate their removal. Our single-center retrospective study included 19 patients with preoperatively radiolucent but echogenic foreign bodies. An intraoperative ultrasound was performed to assist with and confirm the removal of the foreign body. The foreign bodies were vegetal in 15 cases, made of glass in 2 cases, rock in 1 case and undetermined in 1 case. The average length was 4.65 mm (min 1, max 16) and the average width 1.02 mm. All foreign bodies were visible during the intraoperative ultrasound and were no longer visible after their removal. Because intraoperative ultrasound imaging was able to guide the removal of all radiolucent foreign bodies in our study, it can be a useful tool for the removal of radiolucent foreign bodies.

Arthroscopic scapholunate dorsal capsulodesis: A 30-patient case series comparing postoperative splint immobilization versus immobilization and connected K-wiring

The aim of this retrospective study was to compare the results of arthroscopic dorsal capsulodesis performed with or without temporary K-wiring to treat patients who had sustained scapholunate ligament injuries. Our case series included 30 patients with an average age of 37 years (range: 19-55) of whom 12 were female. Dorsal scapholunate capsulodesis was carried out in all patients. In 15 patients, splint immobilization only was used (group I). For the remaining 15 patients, supplementary scapholunate and scaphocapitate K-wiring was performed (group II). The outcomes, whether K-wiring was used or not, were not as good as the outcomes of other published studies. In our study, the reported QuickDASH score was on average higher than 20/100, pain score was higher than 2/10, grip strength was less than 70% of the contralateral side. There was one postoperative complication in the first group and three complications in the second group; five cases of DISI were reported in the first group and three in the second group. There were no significant differences between the two groups. Based on our findings, supplementary K-wiring is not necessary when a dorsal scapholunate capsulodesis is performed. The outcomes of our study were not as good as those of other published series, potentially due to a shorter follow-up and the more severe ligament injuries in our case series.

Tactile sensitivity thresholds for the radial hemi-pulp of the index: A comparison between the Semmes-Weinstein and Cochet-Bonnet tests in 25 healthy subjects

The purpose of this work was to determine whether the Cochet-Bonnet (CB) corneal sensitivity test has a lower cutaneous pulp sensitivity threshold than the Semmes-Weinstein (SW) monofilament test. Tactile sensitivity thresholds for the radial hemi-pulp of the index finger of 25 healthy adult subjects aged 30 years on average were measured using SW and CB esthesiometers. The sensitivity threshold of the radial hemi-pulp of the index was lower with the CB test than with the SW test. The sensitivity and specificity of the CB test on palm wounds still needs to be determined to rule out nerve damage.

Ultrasound for the diagnosis of pyogenic flexor tenosynovitis

The usefulness of ultrasound for making the diagnosis of pyogenic flexor tenosynovitis (PFTS) has been demonstrated. The primary goal of this study was to show that the diameter of the flexor sheath near the A2 pulley was larger when PFTS was present compared to the healthy contralateral finger. The secondary goal was to determine the reproducibility of these ultrasound measurements. Our series included 20 patients (12 men and 8 women) operated due to PFTS. The average age was 41.7 years old. The average diameter of the digital sheath measured near the A2 pulley on transverse and longitudinal ultrasound sections was 5.01mm (transverse 5mm, longitudinal 5.03mm) on infected fingers, and 4.17mm on healthy contralateral fingers. Reproducibility, as measured by the intraclass coefficient between transverse and longitudinal values, was 0.910 for infected fingers and 0.928 for contralateral fingers, thus was excellent. Our hypothesis was confirmed. A unilateral increase of more than 20% in diameter of the flexor sheath measured in transverse or longitudinal ultrasound sections near the pulley A2 contributes to the surgical indication when a patient presents with PFTS.

[Brentuximab vedotin and cord blood transplantation for primary refractory Hodgkin lymphoma following autologous hematopoietic stem cell transplantation]

We report a 26-year-old man with primary refractory nodular sclerosis Hodgkin lymphoma against ABVD, ICE and autologous peripheral blood stem cell transplantation (auto-PBSCT), presenting with multiple epidural spinal cord compressions, paraplegia, and generalized lymphadenopathy. We administrated four cycles of brentuximab vedotin to achieve a complete response, and then conducted cord blood transplantation. This case raises the possibility of a new strategy for refractory Hodgkin lymphoma showing residual lesions after auto-PBSCT.

Thorough debridement and immediate primary wound closure for animal bite injuries of the upper limbs

PURPOSE

Animal bite injuries are often encountered in daily practice. In particular, these injuries of the upper limbs can result in severe functional impairment. We have performed early debridement of contaminated tissue and primary closure for these injuries.

METHODS

The subjects consisted of 15 patients (6 males and 9 females) aged 1-91 years (mean 53.6 years) who visited our hospital due to animal bite injuries (dog in 9 patients, cat in 6). The bite site was the forearm in 5 patients and the hand in 10. In the operating room, contaminated tissue was removed, and primary wound closure was performed after irrigation.

RESULTS

The bite penetrated to the muscle layer in 6 patients, tendon sheath in 5, joint in 1, bone in 1, and involved only the subcutaneous tissue in 3 patients. The mean period until the completion of wound treatment was 19.8 ± 8.4 days. As complications, numbness of finger, metaphalangeal joint contracture and superficial radial nerve injury were observed in each one case. In a patient with bite injury of the palmar and dorsal sides of the thumb reaching the bone, additional debridement was necessary. At the final observation, the visual analog scale was 1.2 ± 1.4, and the Quick Disabilities of the Arm, Shoulder, and Hand score was 9.7 ± 12.2.

CONCLUSIONS

Debridement to achieve wound closure is indispensable in patients with animal bite injuries of the upper limbs. The results of our study suggest that thorough debridement allows primary closure, even for animal bite injuries.

Psychogenic unilateral ptosis with ipsilateral muscle spasm of orbicular oculi

This report describes the rare case of a 27-year-old female patient with conversion disorder who presented unilateral ptosis with ipsilateral muscle spasm of orbicular oculi. The co-existing of ptosis and muscle spasm of orbicular oculi indicates that, in accord with prior reports, the overactivity of orbicular oculi is essential in psychogenic pseudoptosis. The co-existing of unilateral ptosis and ipsilateral muscle spasm of orbicular oculi in the present case leads us to the conclusion that the overactivity of orbicular oculi is essential in psychogenic pseudoptosis.

Secondary hypertrophic pachymeningitis in antiphospholipid syndrome

This report describes a rare case of hypertrophic pachymeningitis secondary to antiphospholipid syndrome in a 37-year-old woman. The patient had a history of antiphospholipid syndrome and developed hypertrophic pachymeningitis subsequently. Pathological examination of the dura mater showed not only fibrous thickening, the typical finding of hypertrophic pachymeningitis, but also thrombosis in the dural microvessels and T cell infiltration without B cell or plasma cell infiltration, suggesting cell-mediated immunity. The dural thickening spontaneously improved and did not deteriorate during corticosteroid therapy. The histological findings and spontaneous remission observed in this case might be characteristic of secondary hypertrophic pachymeningitis with antiphospholipid syndrome. Further investigations are necessary to elucidate the pathophysiology of this novel type of hypertrophic pachymeningitis.

Rectal ulcer in a patient with VZV sacral meningoradiculitis (Elsberg syndrome)

This report describes the case of a 55-year-old woman with varicella-zoster virus (VZV) sacral meningoradiculitis (Elsberg syndrome) who presented with herpes zoster in the left S2 dermatome area, urinary retention, and constipation. Lumbar magnetic resonance imaging showed the left sacral nerve root swelling with enhancement. Thereafter, she suddenly showed massive hematochezia and hemorrhagic shock because of a rectal ulcer. To elucidate the relation between Elsberg syndrome and rectal ulcer, accumulation of similar cases is necessary. To avoid severe complications, attention must be devoted to the possibility of rectal bleeding in the early stage of Elsberg syndrome.

Recurrent spinal cord attacks in a patient with a limited form of neuromyelitis optica

This report describes the case of a 71-year-old woman with a limited form of neuromyelitis optica (NMO) who had a longitudinally extensive spinal cord lesion from the fourth to the tenth thoracic vertebrae. Up to age 75, she had four subsequent recurrences of the myelitis within the same spinal cord area but with no optic neuritis. Anti-AQP4 antibody was seropositive. Recurrence within the same spinal cord area might be a characteristic clinical finding in NMO spectrum disorders. For such patients, examination for anti-AQP4 antibody might be necessary for the diagnosis and therapy of this disorder.

A novel ferritin light chain gene mutation in a Japanese family with neuroferritinopathy: description of clinical features and implications for genotype-phenotype correlations

Neuroferritinopathy is a hereditary neurodegenerative disorder caused by mutations in the ferritin light chain gene (FTL1). The cardinal features are progressive movement disturbance, hypoferritinemia, and iron deposition in the brain. To date, five mutations have been described in Caucasian and Japanese families, but the genotype-phenotype correlations remain to be established. We identified a novel FTL1 mutation (exon 4, c.641/642, 4-nucletotide duplication) in a Japanese family and compared the clinical traits with those previously reported. All mutations but one are insertions in exon 4, resulting in frameshifts. Clinical features are similar among patients with the same mutations. Middle-age onset chorea is common in patients with insertions in the 5' portion of exon 4 including our cases, whereas patients with insertions in the 3' portion of exon 4 develop early-onset tremor, suggesting genotype-phenotype correlations. In this family, male predominance and normal serum ferritin levels are characteristic.

Massive myelinolytic leukoencephalopathy in a patient medicated with low-dose oral methotrexate for rheumatoid arthritis: an autopsy report

The authors describe a 68-year-old female who developed a rapidly progressing leukoencephalopathy involving the cerebrum and brain stem. The disease appeared during low-dose oral methotrexate (MTX) therapy for rheumatoid arthritis. An extensive clinical investigation discounted other possible causes of white matter lesions. Autopsy identified an uninterrupted severe demyelinating, partially liquefactive necrosis-like lesion in the white matter accompanied by astrogliosis and occasional swollen axons therein. The lesion was generally symmetrical, and distributed throughout the whole cerebral white matter except for the bilateral temporal lobes and the rostral part of the frontal lobes. The internal capsules and cerebral peduncles were spongy, and the central and lateral parts of the pons, especially the transverse cerebellopontine tracts, were affected similarly. It was of note that the lesion was accompanied by neither vascular diseases nor lymphocyte infiltration. Thus, the pathological findings were similar to those of a severe form of central and extrapontine myelinolysis, and clearly different from ordinary MTX leukoencephalopathy reported in patients receiving intrathecal or intravenous MTX therapy, known as "disseminated necrotizing leukoencephalopathy". Another possibility is that synergistic effects of several white-matter-damaging disorders may have contributed to the hitherto unknown lesion. To our knowledge, this is the first autopsy record that describes an oral MTX-associated neurological disorder.

[An adult case of bacterial meningitis caused by penicillin-resistant streptococcus pneumoniae]

We report a patient of bacterial meningitis caused by penicillin-resistant streptococcus pneumoniae (PRSP). A 50-year-old Japanese man was admitted after developing a fever and quickly falling into unconsciousness. Neurological examination showed slightly consciousness disturbance and meningeal irritation. A lumbar puncture yielded turbid spinal fluid, with increased cell count (411/mm3), protein (685 mg/dl) and IgG (60.3 mg/dl) but decreased glucose (1 mg/dl). Bacterial meningitis was diagnosed and aminobenzylpenicillin (ABPC) and cefotaxime (CTX) were administered immediately, but they were ineffective. Penicillin-resistant streptcoccus pneumoniae (PRSP) was detected in the blood and spinal fluid, so antibiotics were changed to panipenem/betamipron (PAPM/BP) and vancomycin (VCM) with marked efficacy. With the increase in PRSP patients and documented failure in treatment of pneumococcal meningitis with ABPC and CTX, the need for alternative antibiotic therapy is critical. We emphasize the importance of initial therapy with PAPM/BP and VCM in patients with bacterial meningitis from streptcoccus pneumoniae.

Potential impact of global warming on deciduous oak dieback caused by ambrosia fungus Raffaelea sp. carried by ambrosia beetle Platypus quercivorus (Coleoptera: Platypodidae) in Japan

Deciduous oak dieback in Japan has been known since the 1930s, but in the last ten years epidemics have intensified and spread to the island's western coastal areas. The symbiotic ambrosia fungus Raffaelea sp. is the causal agent of oak dieback, and is vectored by Platypus quercivorus (Murayama). This is the first example of an ambrosia beetle fungus that kills vigorous trees. Mortality of Quercus crispula was approximately 40% but much lower for associated species of Fagaceae, even though each species had a similar number of beetle attacks. It is likely that other oaks resistant to the fungus evolved under a stable relationship between the tree, fungus and beetle during a long evolutionary process. Quercus crispula was probably not part of this coevolution. This hypothesis was supported by the fact that P. quercivorus showed the least preference for Q. crispula yet exhibited highest reproductive success in this species. Therefore, P. quercivorus could spread more rapidly in stands with a high composition of Q. crispula. The present oak dieback epidemic in Japan probably resulted from the warmer climate that occurred from the late 1980s which made possible the fateful encounter of P. quercivorus with Q. cripsula by allowing the beetle to extend its distribution to more northerly latitudes and higher altitudes. Future global warming will possibly accelerate the overlapping of the distributions of P. quercivorus and Q. crispula with the result that oak dieback in Q. crispula will become more prevalent in Japan.

Presynaptic inhibition of cerebellar GABAergic transmission by glutamate decarboxylase autoantibodies in progressive cerebellar ataxia

Autoantibodies against glutamic acid decarboxylase (GAD) have been found in stiff-man syndrome, insulin dependent diabetes mellitus, and progressive cerebellar ataxia. A patient with progressive cerebellar ataxia is described who was positive for GAD autoantibodies, and had Sjögren's syndrome. Immunohistochemical studies using CSF and serum samples from the patient showed immunoreactivities in axon terminals of cerebellar GABAergic neurons. A whole cell patch clamp technique recording from rat cerebellar slices showed that the CSF, presumably through GAD autoantibodies, presynaptically inhibited GABAergic transmission. Intravenous administration of immunoglobulin failed to improve clinical symptoms and immunoreactivities examined after therapy. The findings suggest that GAD autoantibodies play a pathogenic part in reducing GABA release in in vitro slices.

Carboxyl-terminal fragments of presenilin-1 are closely related to cytoskeletal abnormalities in Alzheimer's brains

To clarify the role of presenilin-1 (PS-1) in the pathology of Alzheimer's disease (AD), we tested four antisera to PS-1. The specific antisera to the N-terminus (HSN-2) and C-terminus (HS-C) of PS-1 detected a 44/40kD holoprotein, a 25kD N-terminal fragment (NTF) and a 16kD C-terminal fragment (CTF) of PS-1 in COS-7 cells. The 25kD NTF and 16kD CTF were observed in human brains, and their amounts were not significantly different between the control and AD brains. The antibody HS-C labeled extensive neurofibrillary tangles, dystrophic neurites and curly fibers in the AD brains. In the paired helical filament (PHF) fraction containing A68 protein from AD brains, a smear pattern of CTFs was revealed. Antisera (HS-L292 and HS-L300) to cleavage sites of PS-1 also revealed immunoreactive neurofibrillary tangles in the AD brain sections and the smear pattern of CTFs of A68 protein fraction. The CTFs of PS-1 accumulate with PHF tau, suggesting a close relationship between PS-1 and cytoskeletal abnormalities in AD brains.

Longitudinal study of cerebrospinal fluid levels of tau, A beta1-40, and A beta1-42(43) in Alzheimer's disease: a study in Japan

To clarify the alterations of tau, amyloid beta protein (A beta) 1-40 and A beta1-42(43) in the cerebrospinal fluid (CSF) that accompany normal aging and the progression of Alzheimer's disease (AD), CSF samples of 93 AD patients, 32 longitudinal subjects among these 93 AD patients, 33 patients with non-AD dementia, 56 with other neurological diseases, and 54 normal control subjects from three independent institutes were analyzed by sensitive enzyme-linked immunosorbent assays. Although the tau levels increased with aging, a significant elevation of tau and a correlation between the tau levels and the clinical progression were observed in the AD patients. A significant decrease of the A beta1-42(43) levels and a significant increase of the ratio of A beta1-40 to A beta1-42(43) were observed in the AD patients. The longitudinal AD study showed continuous low A beta1-42(43) levels and an increase of the ratio of A beta1-40 to A beta1-42(43) before the onset of AD. These findings suggest that CSF tau may increase with the clinical progression of dementia and that the alteration of the CSF level of A beta1-42(43) and the ratio of A beta1-40 to A beta1-42(43) may start at early stages in AD. The assays of CSF tau, A beta1-40, and A beta1-42(43) provided efficient diagnostic sensitivity (71%) and specificity (83%) by using the production of tau levels and the ratio of A beta1-40 to A beta1-42(43), and an improvement in sensitivity (to 91%) was obtained in the longitudinal evaluation.

Combination assay of CSF tau, A beta 1-40 and A beta 1-42(43) as a biochemical marker of Alzheimer's disease

Cerebrospinal fluid samples from a total of 157 subjects consisting of 55 patients with sporadic Alzheimer's disease (AD), 34 normal controls, 23 patients with non-AD dementia, and 45 with other neurological diseases were examined by ELISA of tau, A beta 1-40, and A beta 1-42(43). The AD group had a significantly higher level of tau than the normal control group (P < 0.001), and the diagnostic sensitivity was 31% and specificity was 94%. CSF A beta 1-40 levels did not show any significant differences. Although the level of A beta 1-42(43) was decreased significantly in the AD group compared to the control group (P < 0.005), the overlap of A beta 1-42(43) levels among all groups meant that none of the AD samples exceeded the cut-off value, the mean 2SD of normal control subjects. Reduction of A beta 1-42(43) levels in AD resulted in a significant increase in the ratio of A beta 1-40 to A beta 1-42(43) (A beta ratio) as an improved marker. The diagnostic sensitivity and specificity of A beta ratio were 51% and 82% respectively. The three indexes, using the tau level and A beta ratio (tau or A beta ratio, deviation score and tau x A beta ratio), showed better sensitivity (58%, 67%, 69%) and specificity (82%, 86%, 88%) than previously reported methods. Combination assay for CSF tau, A beta 1-40 and A beta 1-42(43) in CSF is a biological marker of AD and may be useful to biochemically monitor subjects under treatment.

Accumulation of amyloid beta protein in transgenic mice

Carboxyl-terminal fragments of beta amyloid precursor protein (betaAPP) were expressed in mice under the transcriptional control of an ubiquitous promoter system, based upon a chicken beta-actin (betaA) promoter combined with cytomegalovirus (CMV) enhancer to obtain a systemic overproduction of amyloid beta protein (Abeta). Three transgene constructs were designed to encode signal peptide and carboxyl-terminal 99 amino acid residues to betaAPP (NOR-beta), methionine and C-terminal 103 amino acid residues of betaAPP (deltaNOR-beta), and methionine and C-terminal 103 amino acid residues with KM-NL substitution of betaAPP (deltaNL-beta). Although the transcriptional mRNA level and post-translational protein level from transgenes showed the same expression pattern, both the expression of Abeta and distribution of Abeta deposits were completely different among these strains. In NOR-beta mice, considerable amounts of Abeta were detected in plasma and Abeta deposits were observed in the pancreas. Brain Abeta deposits and small amounts of plasma Abeta were recognized in deltaNL-beta. These findings indicate that tissue specific processing and transgene constructs are major factors to determine the distribution of Abeta deposits.

Apolipoprotein E accumulates with the progression of A beta deposition in transgenic mice

To study the role of apolipoprotein E (apoE) in vivo in deposits of amyloid beta protein (A beta), a major component of senile plaque amyloid in the brain of patients with Alzheimer disease, the transgenic mice were examined by apoE immunostaining. The mice were systemically overexpressing signal peptide and 99 amino acid residues of the carboxy-terminal fragment of human amyloid beta protein precursor (betaAPP) under control of the powerful cytomegalovirus enhancer/chicken beta-actin promotor. A beta deposits appeared at 4 months and increased with aging in the acinar cells of the transgenic pancreas. Similarly, apoE deposits appeared in the pancreatic acinar cells at 4 months old. The number and size of apoE deposits increased with aging and correlated with the progression of A beta deposits. Interstitial macrophages labeled by apoE immunostaining appeared at 8 months after birth and their number increased with aging. On serial section of the pancreata of 24-month-old mice, approximately 70% of A beta deposits were labeled with the apoE antiserum. ApoE was detected in the highly insoluble formic acid fraction of the transgenic pancreas by an immunoblot study. The Northern blot study revealed no increase in synthesis of endogenous apoE mRNA. These findings indicate that apoE is closely related to progression of A beta deposits with aging and suggest that A beta deposition in the transgenic pancreas is similar to that in the senile plaque of Alzheimer brains. Therefore, our experimental system using transgenic mice will provide a useful tool to analyze the molecular mechanism of A beta deposition in association with apoE in vivo.

Lysosomal generation of amyloid beta protein species in transgenic mice

Soluble amyloid beta protein (A beta)1-40 and highly amyloidogenic A beta 1-42/43 were immunocytochemically labeled in lysosomes of acinar cells and macrophages in the pancreas of transgenic mice systemically expressing a C-terminal fragment of the A beta precursor. A beta 1-42/43 and long A beta species extending their C-termini were detected in the detergent-insoluble fraction. Immunoreactivity of cathepsin D was markedly increased in lysosomes filled with A beta fibrils. These findings indicated that A beta 1-40, A beta 1-42, A beta 1-43 and longer A beta species were generated in the lysosomes of the transgenic pancreas, and suggested that the activation of cathepsin D, a candidate gamma-secretase, leads to acceleration of A beta amyloid formation.

Modified amyloid beta protein ending at 42 or 40 with different solubility accumulates in the brain of Alzheimer's disease

Serial extraction study of Alzheimer's disease (AD) and control brains revealed 4, 3.7 and 3 kD amyloid beta protein (A beta) species accumulated in AD brains. In the fractions extracted with TBS, 10% SDS and formic acid, considerable amounts of A beta species were recovered in SDS fractions besides TBS and formic acid fractions. Immunoblotting with several site-specific antibodies confirmed not only the presence of 4 kD A beta starting at the first amino acid of A beta but also 2 smaller A beta species with modification of their amino-termini in the highly resolutional Tris/Tricine gel system. A beta solubility using these solvents was associated with both modification of the amino-terminus and length of carboxyl-terminus of A beta. Especially, a large amount of modified A beta was found to be accumulated as forms with different solubility in AD brains.

Luxury perfusion phenomenon in acute herpes simplex virus encephalitis

In a patient with acute herpes simplex virus (HSV) encephalitis, positron emission tomography (PET) demonstrated increased cerebral blood flow in the affected temporal lobe accompanied by reduction in the cerebral oxygen extraction fraction and the cerebral metabolic rate of oxygen, i.e., luxury perfusion. Follow-up PET studies showed reduction in cerebral perfusion until it was more closely coupled with oxygen metabolism after the resolution of the acute inflammation. These findings support previous single photon emission computed tomographic data and provide a pathophysiological background for the occurrence of hyperperfusion in HSV encephalitis. This is an interesting example of the luxury perfusion phenomenon occurring in a disease other than cerebral ischemia.