Buccal pulse oximeter is more accurate than finger pulse oximeter in measuring oxygen saturation

Although there have been several anecdotal reports of the use of buccal pulse oximeter monitoring (Spo2) when digital Spo2 monitoring cannot be used, there have been no objective evaluations of the accuracy of buccal Spo2 monitoring. The purpose of this study was to systematically compare buccal Spo2 monitoring to both digital Spo2 and arterial O2 saturation monitoring (Sao2) in both generally anesthetized patients in the operating room (n = 31) and critically ill patients in the intensive care unit (n = 23). Buccal Spo2 probes were prepared by taping a malleable metal bar securely over the back of a Nellcor Oxisensor D-25 probe and bending the metal bar and buccal probe firmly around the corner of the patient's mouth. All buccal and finger Spo2 and Sao2 measurements were made simultaneously during hemodynamic stability. We found that buccal Spo2 was higher than finger Spo2 and agreed more closely with Sao2 for both patient groups (98.1% +/- 2.6%, 96.8% +/- 3.5%, 98.5% +/- 2.5%, respectively [mean +/- SD]). The operating room patients had higher buccal and finger Spo2 and Sao2 (99.3% +/- 1.5%, 98.9% +/- 1.4%, 99.5% +/- 0.7%, respectively) than the intensive care unit patients (96.4% +/- 2.9%, 94.1% +/- 3.5%, 96.6% +/- 3.5%, respectively). Although buccal Spo2 monitoring has several disadvantages (i.e., the probe requires preparation, can be more difficult to place, may be less readily accepted in awake patients, and is often mechanically dislodged during airway maneuvers), we conclude that buccal Spo2 monitoring is a more than adequate oximetry alternative when digital Spo2 monitoring is not an option (digits are unavailable or available digits are mechanically interfered with).

Immunoreactivity to ubiquitin-protein conjugates is present early in the disease process in the brains of scrapie-infected mice

Brains from mice infected with either the 87V or the ME7 strains of mouse-passaged sheep scrapie were taken at stages during the disease process and immunostained to show the localization of ubiquitin-protein conjugates. In both models, conjugates were seen as fine, dot-like structures; as coarser, granular lesions within or adjacent to neurones; and in areas surrounding plaques. The dot-like structures were visible at 28 days post-ME7 infection and at 55 days in 87V-infected mice. In both models, the extent of immunoreactive changes increased as the disease progressed and terminal infection was as described earlier by us (Lowe et al., J. Pathol 1990; 162: 61-66). The patterns of development of these features were distinctive in two ways: progression from region to region was observable and the density of the pathological lesions grew exponentially as the clinical symptoms appeared. The earliest pathological dot-like structures corresponded temporally with the earliest detection of PrPSC by Western blotting, and immunogold electron microscopic investigation of the dot-like lesions indicated that they were the multi-vesicular, lysosome-related, dense bodies that we have described previously in terminal disease (Laszlo et al., J Pathol 1992; 166: 333-341). Until now, ubiquitin-protein conjugates were seen mainly in inclusion bodies associated with the terminal stages of a range of human degenerative diseases. This study establishes that ubiquitin-protein conjugates accumulate in lysosome-related bodies very early and appear to be intimately related to the pathological processes in the animal disorders that we have studied.

Ballooned neurons in several neurodegenerative diseases and stroke contain alpha B crystallin

alpha B crystallin is a protein which has homology with the small cell stress proteins. A characterized antibody to residues 1-10 of alpha B crystallin was used to immunostain tissues containing ballooned (chromatolytic, achromasic) neurons. The tissues included two cases of classical Pick's disease, one case of dementia with swollen achromasic neurons in the cortex, two cases of Alzheimer's disease with large numbers of ballooned neurons, two cases of motor neuron disease, four cases of cortico-basal degeneration, and four cases with areas of brain showing swollen neurons adjacent to recent cerebral infarcts. The anti-alpha B crystallin showed strong diffuse cytoplasmic immunoreactivity of swollen cortical neurons in all the diseases. Astrocytes and oligodendroglial cells were also stained in normal tissues as previously described. Weak diffuse immunoreactivity with an antibody to ubiquitin-conjugates was also seen in the swollen neurons from cases of neurodegenerative disease but not following infarction. Ballooned neurons have been shown to contain phosphorylated neurofilament epitopes not normally present in the perikaryonal region. The presence of alpha B crystallin in ballooned neurons, together with previous data which also indicate its close association with intermediate filaments, suggest that alpha B crystallin may be involved in aggregation and remodelling of neurofilaments in disease. The presence of alpha B crystallin in neurons at the edge of areas of cerebral infarction is likely to reflect cells which are regenerating following damage; its detection may therefore be a marker for such cells. On a practical level, the antibody greatly facilitates the localization of such abnormal neurons in diagnostic histology.

Protein processing in lysosomes: the new therapeutic target in neurodegenerative disease

A little recognised feature of neurons is their large complement of lysosomes. Studies of the accumulation of the abnormal isoform of the prion protein (PrPSC) in the prion encephalopathies and the formation of beta/A4 protein from its precursor in Alzheimer's disease suggest that generation of these key proteins takes place in lysosome-related organelles. The release of hydrolytic enzymes from lysosomes may be a primary cause of neuronal damage. Although molecular genetic approaches have identified protein mutations central to the main neurodegenerative disease, cell biological observations are now beginning to unravel the intracellular pathways involved in the molecular pathogenesis of neurodegeneration: as a result, it is now appropriate to consider therapeutic manipulation of the lysosomal system as an approach to treatment.

Lysosomes as key organelles in the pathogenesis of prion encephalopathies

The causation, structural origin, and mechanism of formation of spongiform lesions in transmissible encephalopathies are unknown. We have used immunogold electron microscopy to locate ubiquitin conjugates, hsp 70, and beta-glucuronidase (markers of the lysosomal compartment) and prion protein (PrP) in both control and scrapie-infected mouse brain. In scrapie-infected brain, lysosomes and lysosome-related structures (multivesicular and tubulovesicular dense bodies) are present in abnormally high numbers in neuronal cell processes. These structures contain PrP, together with the lysosomal markers ubiquitin conjugates, hsp 70, and beta-glucuronidase, which could also be identified spilling from tubulovesicular dense bodies into areas of early rarefaction in neuronal processes; we suggest that these areas of rarefaction are the precursor lesions of spongiform change. We advance the hypothesis that spongiform change is brought about by cytoskeletal disruption in neuronal processes caused by liberation of hydrolytic enzymes from lysosomes overloaded with the abnormal isoform of PrP (PrPsc). We suggest that the lysosomal system is probably acting as the bioreactor for processing of normal PrP to the abnormal isoform. The continuous production of increasing quantities of abnormal PrPsc in lysosome-related bodies will eventually cause disruption of the lysosomal membrane with destruction of the neuronal cytoskeleton and the initiation of vacuolation. Later, death of the cell will be associated with release of the PrPsc isoform into the extracellular environment. Repeated rounds of phagocytosis, lysosomal biogenesis of PrPsc, lysosomal membrane rupture, hydrolytic enzyme release, and neuronal lysis will lead to an exponential increase in cell damage and cell death.(ABSTRACT TRUNCATED AT 250 WORDS)

alpha B crystallin expression in non-lenticular tissues and selective presence in ubiquitinated inclusion bodies in human disease

alpha B crystallin is a lens protein which has homology with the small heat-shock proteins and is also expressed in non-lenticular tissues. Polyclonal antibodies have been raised to a synthetic peptide corresponding to residues 1-10 of alpha B crystallin. The antiserum detects a 20 kDa polypeptide on nitrocellulose replicas after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate of extracts of heart muscle known to be rich in alpha B crystallin. Staining of normal human tissues reveals immunoreactivity of lens capsular epithelium, skeletal muscle, cardiac muscle, smooth muscle, renal tubular epithelium, Schwann cells, and glial cells, as has been described by other workers. In addition, positive staining of normal thyroid epithelium, colonic epithelium, and stratified squamous epithelium was seen. Tissues known to contain ubiquitinated inclusion bodies were immunostained with the anti-alpha B-crystallin antiserum. Staining of cortical Lewy bodies, astrocytic Rosenthal fibres, and hepatic Mallory bodies was seen, but only a proportion of inclusions were positive. Neurones containing the ubiquitinated inclusions of Alzheimer's disease were only very rarely immunostained and the ubiquitinated inclusions of motor neurone disease were not detected by the antiserum. Reactive astrocytes in cerebral tissues were strongly immunostained. The results suggest that alpha B crystallin is involved in the formation of ubiquitinated inclusion bodies that have associated intermediate filaments and support previous observations on the localization of a brain-specific ubiquitin carboxy-terminal hydrolase which similarly divides ubiquitinated filamentous inclusions in the central nervous system into two main groups.

Screening recommendations for gestational diabetes mellitus

As a result of extensive experiences in multiple centers and a review of the current literature, we conclude that a plasma glucose level obtained 1 hour after a 50 gm oral glucose challenge is the "best" gestational diabetes mellitus screening test. This universal screening is performed at least once during pregnancy. The screening threshold should be no higher than 140 mg/dl, or an unacceptable loss in sensitivity occurs. Universal screening for gestational diabetes mellitus is justified by morbidity reduction, cost, and protocol simplicity and ease.

The latent membrane protein-1 in Epstein-Barr virus-transformed lymphoblastoid cells is found with ubiquitin-protein conjugates and heat-shock protein 70 in lysosomes oriented around the microtubule organizing centre

Immunofluorescence studies on Epstein-Barr virus (EBV)-transformed lymphoblastoid cells have previously shown that the latent membrane transforming protein (LMP-1) is found in patch-like inclusions which also immunostain for vimentin. We now show that EBV transformation causes a major reorganization of intermediate filaments, microtubules, mitochondria, and lysosomal elements, which generally become oriented around the microtubule organizing centre. Immunogold electron microscopy shows that LMP-1 is primarily concentrated in secondary lysosomes together with ubiquitin-protein conjugates and heat-shock protein 70. Intermediate filament inclusion formation with the above characteristics may be a general response triggered by other membrane glycoproteins; as seen, for example, in major human neurodegenerative diseases such as diffuse Lewy body disease.

Ubiquitin in health and disease

Studies in recent years have shown that ubiquitin has increasingly important functions in eukaryotic cells; roles which were previously not suspected in healthy and diseased cells. The interplay between molecular pathological and molecular cell biological findings has indicated that ubiquitin may be pivotal in the cell stress response in chronic degenerative and viral diseases. Furthermore, the studies have led to the notion that ubiquitination may not only serve as a signal for nonlysosomal protein degradation but may be a unifying covalent protein modification for the major intracellular protein catabolic systems; these can act to identify proteins for cytosolic proteinases or direct intact and fragmented proteins into the lysosome system for breakdown to amino acids. This unifying role could explain why ubiquitin is restricted to eukaryotic cells, which possess extensive endomembrane systems in addition to a nuclear envelope. Protein ubiquitination is a feature of most filamentous inclusions and certain other intracellular conglomerates that are found in some degenerative and viral diseases. The detection of ubiquitin-protein conjugates is not of great diagnostic importance in these diseases. Protein ubiquitination is not only essential for the normal physiological turnover of proteins but appears to have been adapted as part of an intracellular surveillance system that can be activated by altered, damaged, or foreign proteins and organelles. The purpose of this system is to isolate and eliminate these noxious structures from the cell: as a cytoprotective mechanism this appears to have evolved in the cell akin perhaps to an 'intracellular immune system'. Other heat shock proteins such as hsp 70 may be involved in this process. It is apparent that ubiquitin has a role in embryonic development. Protein ubiquitination is presumably involved in the reorganisation of cytoplasm that accompanies cell differentiation. Ubiquitin is also necessary for the gross intracellular degradative processes which are consequent upon programmed cell death. Cell elimination is of key importance for a number of developmental morphogenetic changes. An understanding of the molecular details of these processes will no doubt provide further insights into the wide ranging roles of ubiquitin in the life process. As it says in the book 'Ubiquitin'; there is no doubt that ubiquitin is a 'lucky' protein. It is lucky in many ways: lucky for scientific progress, lucky for biomedical scientists and lucky for life! If you have not already done so, why don't you get lucky and look for a role for ubiquitin in your experimental system. As Avram Hershko has said "there is plenty to go round"!

Immunogold localisation of ubiquitin-protein conjugates in primary (azurophilic) granules of polymorphonuclear neutrophils

Ubiquitin-protein conjugates are found in the primary (azurophilic) lysosome-related granules but not in the secondary (specific) granules in mature polymorphonuclear neutrophils prepared from bone marrow. This is the first reported demonstration of ubiquitin-protein conjugates in lysosome-related membrane-bound vesicles in granulocytes and complements our previous findings of ubiquitinated proteins in lysosomes of fibroblasts. The significance of the selective presence of conjugates in only one of the two main types of neutrophil granules remains to be elucidated but may relate to the presence of the complement of acid hydrolases, including proteases, in the azurophilic granules compared to the specific granules. Ubiquitin-protein conjugates may enter the primary granules during neutrophil maturation by an autophagic process or by a heterophagic process during the fusion of phagosomes with primary granules. Alternatively protein ubiquitination may be involved in granule biogenesis.

Ubiquitin conjugate immunoreactivity in the brains of scrapie infected mice

Sections of brain from normal mice or clinically-ill mice infected with either the 87V or the ME7 strains of sheep scrapie were immunostained to show the localization of ubiquitin-protein conjugates or a specific marker of disease, the scrapie-associated fibril protein (PrP). In both scrapie models immunoreactive ubiquitin-protein conjugates were seen in thread-like structures found throughout the neuropil, in inclusion bodies within vacuolated neurones, and in areas surrounding anti-PrP positive amyloid plaques. The PrP protein was visualized in diffuse deposits in highly vacuolated parts of the scrapie-affected brain, and focally in amyloid plaques, microglia and neuronal processes. The ubiquitin-protein conjugate staining of scrapie amyloid plaques is very similar to that seen in the plaques of Alzheimer's disease. The ubiquitinated intraneuronal inclusion bodies seen in scrapie resemble the granulovacuolar lesions also seen in Alzheimer's disease, but appear much larger and possibly correspond to material in giant autophagic vacuoles. We suggest that these inclusions may be the result of ubiquitinated abnormal proteins being directed to the lysosomal system, and that scrapie and Alzheimer's disease share at least some common processes of neurodegeneration.

Measurement of cervical length in pregnancy: comparison between vaginal ultrasonography and digital examination

Evaluation of the gravid cervix uteri is an important part of prenatal care, especially in the patient at risk for preterm birth. Seeking a method of cervical length measurement that could be used easily regardless of patient habitus, location of the cervix, and gestational age, we used a vaginal probe with a 240 degrees scanning angle in gravidas at various gestational ages to test the theoretical advantages of the wide scanning angle. Among the first 201 examinations, cervical length was measured successfully in 99.5% of cases. This success rate compares favorably with those of abdominal sonography and vaginal sonography using the standard 90 degrees scanning angle sector probes. We also compared this method with digital examination in a double-blind fashion. Only a fair degree of association between sonographic cervical measurements and measurements obtained by digital examination was found, reflected in a correlation coefficient of 0.49.

Distinction of NPY receptors in vitro and in vivo. II. Differential effects of NPY and NPY-(18-36)

We have studied the hemodynamic effects of neuropeptide Y (NPY) and its COOH-terminal fragment NPY-(18-36) in conscious rats. Intra-arterial injection of NPY rapidly elevated systemic vascular resistance (SVR), which remained high for greater than 30 min. Cardiac output (CO) decreased, and it remained low for greater than 30 min. Accordingly, blood pressure rose only transiently and returned to base-line values within 5 min. The reduction of CO could be attributed to a decreased stroke volume with an only marginal reduction of heart rate. Thus a direct cardiodepressive effect of NPY rather than baroreflex activation appears to be the major cause of the reduced CO. In vitro experiments excluded the possibility that NPY has direct negative inotropic effects and suggest that its cardiodepressive action is caused by coronary vasoconstriction or by presynaptic inhibition of norepinephrine release. Intra-arterial injections of NPY-(18-36) caused different hemodynamic effects. NPY-(18-36) decreased CO in a manner similar to that seen with NPY but initially did not elevate SVR, resulting overall in a reduced blood pressure. Only later, when blood pressure was reduced, was an elevation of SVR observed, which could be associated with increased plasma levels of catecholamines, angiotensin II, vasopressin, and NPY. Thus NPY-(18-36) mimics the cardiac effects of NPY but does not elicit its vascular effects. As NPY-(18-36) discriminates between NPY receptor subtypes in vitro, we conclude that the cardiac and vascular effects of NPY are mediated by distinct receptor subtypes.

Ubiquitin carboxyl-terminal hydrolase (PGP 9.5) is selectively present in ubiquitinated inclusion bodies characteristic of human neurodegenerative diseases

The recent discovery that brain PGP 9.5 is a ubiquitin carboxyl-terminal hydrolase suggests that the role of this protein should be studied in relation to ubiquitinated cellular inclusions characteristic of several chronic human degenerative diseases. Formalin-fixed, paraffin-processed sections known to contain ubiquitin-protein conjugate immunoreactivity in cortical Lewy bodies, neurofibrillary tangles, Rosenthal fibres, Pick bodies, spinal inclusions in motor neurone disease, and Mallory's hyaline in alcoholic liver disease were immunostained to localize PGP 9.5. The majority of cortical Lewy bodies in diffuse Lewy body disease showed immunoreactivity for PGP 9.5. In Alzheimer's disease, only a minority of loosely arranged globose-type neurofibrillary tangles were immunostained together with a minority of neurites surrounding senile plaques. In cerebellar astrocytomas, the periphery of the majority of Rosenthal fibers was immunostained in addition to strong diffuse cytoplasmic immunostaining in some astrocytes lacking apparent Rosenthal fibers. In Pick's disease, there was no immunostaining of inclusions but there was intense immunostaining of swollen Pick cells. No spinal inclusions in motor neurone disease were stained; however, anterior horn neurones appear to show increased levels of PGP 9.5 compared with those from control cases. No immunostaining of hepatic Mallory's hyaline was demonstrable, which accords with suggestions that PGP 9.5 is a tissue-specific ubiquitin C-terminal hydrolase isoenzyme. The differential detection of a ubiquitin C-terminal hydrolase in different forms of ubiquitinated inclusion body in the nervous system may form the basis of a method for assessment of the staging of inclusion body biogenesis and give insight into the dynamics of inclusion body formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diffuse Lewy body disease: correlative neuropathology using anti-ubiquitin immunocytochemistry

Diffuse Lewy body disease is an important pathological substrate of the common syndrome of parkinsonian dementia. The new technique of anti-ubiquitin immunocytochemistry has been used in a correlative quantitative neuropathological study of fifteen cases of diffuse Lewy body disease, showing that the severity of dementia is related to cortical Lewy body density, whilst subcortical abnormalities make a much less significant contribution. Cortical senile plaques also appear to be part of the pathology of diffuse Lewy body disease and should not therefore be used as an isolated diagnostic criterion for Alzheimer's disease. Diagnostic criteria for diffuse Lewy body disease are discussed.

Inclusion bodies in motor cortex and brainstem of patients with motor neurone disease are detected by immunocytochemical localisation of ubiquitin

Histological sections of cerebral motor cortex, brainstem, and spinal cord from 10 cases of clinically diagnosed motor neurone disease (MND) and 10 control cases were examined by conventional histology and immunocytochemical methods to localise ubiquitin. Intracytoplasmic inclusion bodies were identified in motor neurones of hypoglossal nuclei and appeared specific for MND. Similar inclusions were found in both large pyramidal cells and small neurones in the motor cortex, and were restricted to 4 cases having the amyotrophic lateral sclerosis form of MND with severe degeneration of corticospinal tracts. As reported in earlier studies, cellular inclusion bodies were identified in motor neurones of spinal cord from cases of MND but not in control material. Ubiquitin inclusions in motor neurones appear to be markers for the degenerative process causing neuronal loss in MND and there appears to be a close association between the anatomical location of inclusions and clinical manifestations of disease.

Immunocytochemical profile of neurofibrillary tangles in Down's syndrome patients of different ages

Brains were obtained at autopsy from 24 patients with Down's syndrome, ranging in age from 13 to 71 years. Neurofibrillary tangle containing neurones of the hippocampus were stained using a Palmgren silver method and immunocytochemically (PAP) using antisera to paired helical filament protein, human tau protein and ubiquitin, as primary antibody. Counts of cells stained by each method were compared. In patients under 50 years of age, in whom only a limited number of tangle bearing cells were present, the number of profiles visualized with silver, anti-paired helical filament and anti-tau methods were similar. However, in patients over 50 years of age (and in certain of those under 50), in whom numerous tangles were present, the number of cell profiles visualized with silver and anti-paired helical filament methods were still similar though anti-tau detected fewer positive cells. This was because of the increased presence, in such patients, of extracellular tangles which had "lost" anti-tau immunoreactivity. Such data suggest that although tau protein forms a major antigenic determinant of neurofibrillary tangles in Down's syndrome (as it does in Alzheimer's disease) this protein may only decorate the basic paired helical filament protein skeleton, and is removed by macrophagic activity upon neuronal death. In all patients, anti-ubiquitin revealed fewer tangles than any other method. It is possible that ubiquitin may be present only transiently, within tangles perhaps following initial formation and lasting only as long as the normal protein degradation processes remain viable within the diseased neurone.

Ubiquitin gene expression in brain and spinal cord in motor neurone disease

A restriction fragment of the coding region of a human ubiquitin gene has been used in Northern analyses of RNA prepared from human motor cortex and anterior horn region of cervical spinal cord. The analyses show that there is a substantial increase (approximately two-fold) in the expression of a polyubiquitin gene in motor cortex and spinal cord from patients with motor neurone disease compared to these tissues from control cases. Polyubiquitin gene expression in other organisms is associated with physical or chemical cell stresses. The data indicate that the primary stresses which result in the generation of ubiquitinated filamentous inclusion bodies in neurones in motor neurone disease also result in increased transcription of a gene coding for a polyprotein of ubiquitin.

An analysis of the morphology of senile plaques in Down's syndrome patients of different ages using immunocytochemical and lectin histochemical techniques

The morphology of the senile plaque (SP), within the hippocampus and the temporal cortex, has been examined in 21 patients with Down's syndrome (DS), dying between the ages of 13 and 65 years, using immunocytochemical and lectin histochemical methods, as well as with a conventional silver staining technique. The earliest changes detectable within these areas of brain in the younger patients involved a fine diffuse deposition of amyloid (A4) protein and a uniform granular accumulation of an oligosaccharide recognized by the lectin from Canavalia ensiformis (ConA). At this stage, these 'pre-plaque' areas are unrecognizable using silver staining. Later the conventional SP morphology becomes apparent; the A4 protein aggregates into the usual plaque core and neurites appear with silver staining. The fine ConA positive material concentrates into large clumps and becomes recognizable by other lectins such as PSA, WGA and ePHA, which bind to mannose containing structures in an increasingly complex form. It is suggested that the development of the pathological changes of Alzheimer's disease, in patients with DS (and also in AD itself) involves a primary deposition of amyloid protein in conjunction with the accumulation of an as yet unidentified oligosaccharide. These changes precede the neuronal response that is characterized by the formation of neurites and the accumulation of neurofibrillary tangles that ultimately leads to cell death.

Rosenthal fibres are based on the ubiquitination of glial filaments

Immunocytochemical localization of the cell stress-associated protein ubiquitin was performed on human lesions containing Rosenthal fibres. Ubiquitin was localized around the periphery of classical Rosenthal fibres but not in the amorphous central areas; the ubiquitin-positive regions corresponded to the immunocytochemical localization of glial fibrillary acidic protein (GFAP). Compact bundles of GFAP in glial processes without a non-staining core were also associated with ubiquitin, while loosely aggregated cellular GFAP was not. The relationship between compact bundles of GFAP and the amorphous osmiophilic central component of Rosenthal fibres has been uncertain. These data, however, show that the compact bundles of glial filaments are distinct from normal GFAP in being associated with ubiquitin. A role for ubiquitin in Rosenthal fibre formation is suggested. We propose that the term Rosenthal fibre be restricted to mean the hyaline amorphous core of these structures, while realizing that this is based on a wider abnormality of surrounding glial fibrillary acidic protein filaments.

Anti-ubiquitin immunocytochemistry is more sensitive than conventional techniques in the detection of diffuse Lewy body disease

Brainstem and cortical Lewy bodies in diffuse Lewy body disease show intense immunoreactivity to antibodies against ubiquitin. Quantitative studies show that the novel neuropathological technique of anti-ubiquitin immunocytochemistry is more than twice as sensitive as conventional haematoxylin and eosin stains in detecting cortical Lewy bodies. Anti-ubiquitin immunocytochemistry should be regarded as the method of choice for the diagnosis and quantification of diffuse Lewy body disease.

A filamentous inclusion body within anterior horn neurones in motor neurone disease defined by immunocytochemical localisation of ubiquitin

Using an immunocytochemical method to localise antibodies to ubiquitin, filamentous inclusion bodies were seen in spinal anterior horn neurones in cases of motor neurone disease (MND) but not in any control cases. These inclusion bodies appeared to be closely associated with classical Bunina bodies and immuno-electron microscopy suggested that they were based on arrays of straight 10-15 nm filaments together with some granular material. These observations link the protein ubiquitin with a chronic neurodegenerative disease and extend previous observations of a close association between filamentous inclusion bodies and ubiquitin. Ubiquitin-filament inclusions should be regarded as a new hallmark in the histological diagnosis of MND.

Ubiquitin is a component of neurofibrillary tangles in a variety of neurodegenerative diseases

Ubiquitin has been shown to be a component of neurofibrillary tangles in Alzheimer's disease. We now show immunocytochemically that it is also a component of neurofibrillary tangles in several other neurodegenerative diseases of diverse aetiology, including Down's syndrome, dementia pugilistica and postencephalitic parkinsonism, and in normal ageing. Ubiquitin immunoreactivity is not, however, generally found in the neurofibrillary tangles of progressive supranuclear palsy. These findings show that while associated ubiquitin is not a feature unique to the tangles of Alzheimer's disease, it is not simply a non-specific response to the presence of an inclusion body within the cell. The observations suggest that ubiquitin may have an important role in the formation of neurofibrillary tangles in a variety of neurodegenerative diseases.

CNS amyloid proteins in neurodegenerative diseases

The amyloid plaques found in neurodegenerative diseases show considerable morphologic diversity. Two amyloidogenic proteins have been isolated from the brains of humans and animals with neurodegenerative diseases--beta-protein from Alzheimer's disease (AD) and Down's syndrome, and prion protein (PrP) from scrapie and Creutzfeldt-Jakob disease (CJD). Using monoclonal antibodies to a synthetic peptide corresponding to a portion of beta-protein and rabbit antiserum to hamster scrapie PrP 27-30, we examined in situ amyloid plaques on sections from cases of neurodegenerative diseases, including cases with a spectrum of plaque types. Anti-beta-peptide stained cerebrovascular and plaque core amyloid in all AD cases as well as cerebrovascular amyloid and senile plaque core amyloid in five elderly CJD cases. Anti-PrP stained plaques in CJD, kuru, and Gerstmann-Sträussler syndrome cases but not cerebrovascular amyloid or plaques in AD. Dual localization experiments showed that in cases with a mixture of plaque types, the antibodies identified different populations of plaques that showed anatomic heterogeneity. Colocalization of the two proteins was not observed in any plaque type. The data suggest that in neurodegenerative diseases two major plaque types exist, which have different etiologic origins. Our results emphasize the need for classification of CNS amyloids based not on their morphology but on the macromolecular components comprising these pathologic polymers.

Ubiquitin is a common factor in intermediate filament inclusion bodies of diverse type in man, including those of Parkinson's disease, Pick's disease, and Alzheimer's disease, as well as Rosenthal fibres in cerebellar astrocytomas, cytoplasmic bodies in muscle, and mallory bodies in alcoholic liver disease

Polyclonal antibodies were raised which have a high affinity for conjugated ubiquitin. Immunocytochemistry was performed on paraffin sections of tissues showing well-characterized inclusion bodies. Ubiquitin was found as a component of the intermediate filament inclusion bodies characteristic of several major diseases including Lewy bodies of Parkinson's disease, Pick bodies of Pick's disease, Mallory bodies of alcoholic liver disease, cytoplasmic bodies of a specific myopathy, and Rosenthal fibres within astrocytes. Ubiquitin was also present in the three histological lesions characteristic of Alzheimer's disease. These observations suggest a fundamental role for ubiquitin in the formation of intermediate filament inclusion bodies in man, and have implications regarding the pathogenesis of these important diseases.

Immunohistochemical evidence for the derivation of a peptide ligand from the amyloid beta-protein precursor of Alzheimer disease

A monoclonal antibody to a synthetic peptide consisting of residues 8-17 of the amyloid beta protein of Alzheimer disease was used in immunohistochemical studies to reveal binding sites for this peptide in vesicular elements in the islets of Langerhans of the pancreas and the zona reticularis of the adrenal gland. These binding sites may represent a specific membrane receptor. These results, together with similarities in structural features between the precursors for epidermal growth factor and beta protein, suggest that the beta-protein precursor may be processed to release an active peptide ligand rather than acting as a membrane receptor. In Alzheimer disease, abnormal processing of this active peptide precursor may result in the deposition of beta-protein amyloid fibrils in the brain.

Immunogold labeling of cerebrovascular and neuritic plaque amyloid fibrils in Alzheimer's disease with an anti-beta protein monoclonal antibody

A monoclonal antibody raised to a synthetic peptide consisting of residues 8 to 17 of the amyloid beta protein of Alzheimer's disease was employed for immunogold electron microscopic studies on amyloid fibrils of cerebrovascular walls and neuritic plaques in this disease. Electron microscopy revealed a specific gold labeling of the amyloid fibrils in these structures. This provides ultrastructural evidence that beta protein is intimately associated with the amyloid fibril. With previous chemical evidence, this observation supports the concentration that it is an intrinsic component of the fibril.

Isolated senile plaque cores in Alzheimer's disease and Down's syndrome show differences in morphology

Frontal and temporal cortical tissue from the brains of elderly cases of Down's syndrome was used to make preparations of neuronal cell bodies containing senile plaque cores. Polarisation microscopy revealed normal "classical" plaque cores, and also a high proportion of unusual "amorphous" plaque cores which we have not seen in Alzheimer's disease. These two forms were easily distinguished by electron microscopy. This suggests that late Down's syndrome may not be an exact model for Alzheimer's disease.

Monoclonal antibodies raised against a subsequence of senile plaque core protein react with plaque cores, plaque periphery and cerebrovascular amyloid in Alzheimer's disease

Four monoclonal antibodies (1D2/1/2, 1G10/2/3, 3B6/1/1, 4D12/2/6) were raised against a synthetic peptide consisting of residues 8-17 of a protein reported to be common to senile plaque cores, cerebrovascular amyloid and neurofibrillary tangles in Alzheimer's disease. In an immunoperoxidase study of Alzheimer brain tissue, these antibodies stained plaque and vascular amyloid but not tangles, suggesting that the polypeptide chain in the region of residues 8-17 is exposed in the former two but, if present, inaccessible in the latter. In addition, staining of granular material in the plaque periphery was observed. These antibodies will be useful tools for future work on the origin of this protein.

Endogenous origin of microbiologically-inactive cobalamins (cobalamin analogues) in the human fetus

The cobalamin content of placenta, maternal and fetal sera was assayed by methods which measure microbiologically-active and microbiologically-inactive cobalamins. Only microbiologically-active cobalamins were present in the placenta but both types were present in both maternal and fetal circulations. We conclude that only microbiologically-active cobalamins cross the placenta and that the microbiologically inactive cobalamins in the fetus must arise by metabolism in situ.

Polypeptide components of bovine heart cytochrome c oxidase. Cross-identifications in two high-resolution polyacrylamide-gel electrophoresis systems

Two-dimensional polyacrylamide-gel electrophoresis has been used to correlate polypeptide components of bovine heart cytochrome c oxidase that are resolved by two high resolution systems. The systems utilise chloral hydrate (2,2,2-trichloroethane-1,1-diol), which resolves fifteen components, and sodium dodecyl sulphate and urea, which resolves thirteen components. Seven components have been isolated and identified from their amino acid compositions in terms of polypeptides for which the amino acid sequence is known. Full resolution of all components present in this enzyme cannot be accomplished using any single-dimension system currently available.

The isolation and amino acid composition of senile plaque core protein

A new method has been developed for the isolation of intact senile (neuritic) plaque cores from post-mortem brains of patients with Alzheimer's disease. The plaque cores were found to be insoluble in various protein denaturants. The amino acid composition of the plaque core protein does not resemble that of any known form of amyloid.

Ion-exchange chromatography in the presence of the non-ionic dissociating agent chloral hydrate. Application to a membrane protein, bovine heart cytochrome c oxidase

In previous work we have shown that aq. 100% (w/v) chloral hydrate (2,2,2-trichloroethane-1,1-diol) is a potent non-ionic protein dissociating agent. We have employed it in systems of polyacrylamide-gel electrophoresis and have demonstrated the presence of 15 components in a preparation of bovine heart cytochrome c oxidase [Griffin & Landon (1981) Biochem. J. 197, 333-344]. Here we describe the use of solutions containing aq. 100% (w/v) chloral hydrate in the ion-exchange column chromatographic separation on CM-cellulose of the alpha- and beta-chains of human haemoglobin, which we have employed as a model protein of known structure. We also describe the use of similar procedures in order to fractionate the polypeptide components of bovine heart cytochrome c oxidase. An effective separation has been obtained and we suggest that chloral hydrate-containing solutions could have general application in the ion-exchange-chromatographic analysis of membrane proteins, a procedure that has had restricted use owing to the inadequacy of non-ionic dissociating agents available previously.

Transglutaminase-catalysed incorporation of putrescine into denatured cytochrome. Preparation of a mono-substituted derivative reactive with cytochrome c oxidase

Guinea pig liver transglutaminase has been used to incorporate putrescine into horse heart cytochrome c. The native protein showed essentially no incorporation, while ethanol-denatured cytochrome c incorporated almost 1 mol putrescine per mol protein. No increase in this level of modification was obtained when maleylated cytochrome c and the tryptic peptides of cytochrome c were used as substrates. Analysis of the modified ethanol-denatured cytochrome c by tryptic cleavage and peptide isolation showed that glutamine-42 of the intact protein is the site of incorporation of radioactively labelled putrescine. Ethanol-denatured cytochrome c that was specifically modified at glutamine-42 by incorporated of putrescine could be readily renatured. The renatured modified protein showed reactivity with cytochrome c oxidase comparable to that of the original native protein.

Additional components of bovine heart cytochrome c oxidase demonstrated by high-resolution polyacrylamide-gel electrophoresis in the presence of chloral hydrate

We have shown that aq. 100% (w/v) chloral hydrate (2,2,2-trichloroethane-1,1-diol) dissociates bovine heart cytochrome c oxidase. We have developed new procedures of polyacrylamide-gel electrophoresis in the presence of chloral hydrate that permit variation in the pH of the separation, and, by using these procedures, we have observed 15 components in preparations of the enzyme. This number contrasts with the eight bands that were seen on electrophoresis in the presence of SDS (sodium dodecyl sulphate) and urea. We have isolated material from these eight bands and have characterized each by electrophoresis in the presence of chloral hydrate. Twelve of the fifteen components that were seen by electrophoresis in chloral hydrate were identified as constituents of the eight bands seen by electrophoresis in the presence of SDS and urea. Two-dimensional electrophoretic separations confirmed these identifications ans showed that the other three components which were resolved as discrete bands by electrophoresis in the presence of chloral hydrate appeared to be diffusely present in the electrophoretic separations performed in the presence of SDS and urea, which suggested anomalous behaviour in that detergent. Trypsin treatment of cytochrome c oxidase caused total loss, as observed by electrophoretic separations in the presence of chloral hydrate, of a number of components. The trypsin-sensitive components included all of those that behaved anomalously in the presence of SDS and urea. Chloral hydrate is a potent non-ionic dissociating agent for cytochrome c oxidase and its use in polyacrylamide-gel electrophoresis, with variation in the pH of the gel, permits charge-dependent separations that should have general application in the analysis of membrane proteins.