RESUMEN
Squamous papillomas are rare benign lesions that can be found in the oesophagus. It has been theorised that irritation of the esophageal mucosa leads to squamous papilloma formation. There is evidence to suggest that squamous papillomas of the distal oesophagus are related to irritation due to reflux of gastric acid. In this case report, we describe for the first time a squamous papilloma of the upper oesophagus located just distal to an inlet patch. Inlet patches consist of gastric mucosa located in the proximal oesophagus. They are capable of producing acid. This case raises the possibility that just as squamous papillomas of the distal oesophagus may be related to acid exposure from the reflux of gastric acid, squamous papillomas of the proximal oesophagus may be related to acid exposure from the locally-produced acid of inlet patches.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Papiloma , Bahías , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/etiología , Neoplasias Esofágicas/patología , Humanos , Papiloma/etiología , Papiloma/patologíaRESUMEN
BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global health emergency. Despite the widely hypothesized role of a cytokine storm in disease severity, no study thus far has explored the association between immunosuppression and disease severity in patients hospitalized with COVID-19. OBJECTIVE: This study aimed to examine the association between the use of immunosuppressant medication and outcomes of patients hospitalized with COVID-19. METHODS: Nine hundred and eighty-one consecutive patients hospitalized between 12 March 2020 and 15 April 2020, who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were enrolled in this cohort study and subdivided by immunosuppression status. The patients were followed up for a minimum of 28 days (median 37 days) for the primary end-point of mortality. Secondary end-points included the composite of intubation or death, and the composite of mortality, intubation or continuous positive airway pressure (CPAP) requirement. RESULTS: During the follow-up period, 354 (36.1%) of study patients died. The immunosuppressed cohort (n = 31) had significantly higher mortality rates (aHR: 2.067, 95% CI: 1.20-3.57, P = 0.009). There was no association between immunosuppression and the composite end-point of mortality or intubation (aHR: 1.49 95% CI: 0.88-2.51, P = 0.14) and of the composite end-point of mortality, intubation or CPAP (aHR: 1.36 95% CI: 0.81-2.30 P = 0.245). CONCLUSION: In this cohort study of 981 confirmed COVID-19 patients consecutively hospitalized at a large North West London hospital, immunosuppressant use was associated with significantly higher mortality rates. These results support the current UK government's early isolation ('shielding') policy for these individuals and should be used to guide future research.
Asunto(s)
COVID-19/epidemiología , COVID-19/inmunología , Hospitalización , Huésped Inmunocomprometido , Neumonía Viral/epidemiología , Neumonía Viral/inmunología , Anciano , Anciano de 80 o más Años , COVID-19/mortalidad , Presión de las Vías Aéreas Positiva Contínua , Femenino , Mortalidad Hospitalaria , Humanos , Inmunosupresores/administración & dosificación , Londres/epidemiología , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/mortalidad , Neumonía Viral/virología , SARS-CoV-2RESUMEN
COVID-19 has caused a major global pandemic and necessitated unprecedented public health restrictions in almost every country. Understanding risk factors for severe disease in hospitalised patients is critical as the pandemic progresses. This observational cohort study aimed to characterise the independent associations between the clinical outcomes of hospitalised patients and their demographics, comorbidities, blood tests and bedside observations. All patients admitted to Northwick Park Hospital, London, UK between 12 March and 15 April 2020 with COVID-19 were retrospectively identified. The primary outcome was death. Associations were explored using Cox proportional hazards modelling. The study included 981 patients. The mortality rate was 36.0%. Age (adjusted hazard ratio (aHR) 1.53), respiratory disease (aHR 1.37), immunosuppression (aHR 2.23), respiratory rate (aHR 1.28), hypoxia (aHR 1.36), Glasgow Coma Scale <15 (aHR 1.92), urea (aHR 2.67), alkaline phosphatase (aHR 2.53), C-reactive protein (aHR 1.15), lactate (aHR 2.67), platelet count (aHR 0.77) and infiltrates on chest radiograph (aHR 1.89) were all associated with mortality. These important data will aid clinical risk stratification and provide direction for further research.
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Betacoronavirus , Infecciones por Coronavirus/epidemiología , Neumonía Viral/epidemiología , Anciano , Anciano de 80 o más Años , COVID-19 , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/mortalidad , Femenino , Hospitalización , Humanos , Londres/epidemiología , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/mortalidad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2RESUMEN
In patients with malignant pheochromocytoma and paraganglioma, 131I-MIBG radiotherapy can achieve an objective response rate of 30-50% with the dose limiting toxicity being hematologic. Patients with disseminated disease, who also have a few index bulky or symptomatic lesions, may benefit from the addition of targeted external beam radiotherapy alone or in combination with systemic 131I-MIBG. The records of patients with malignant paraganglioma who were treated with external beam radiotherapy at the University of Pennsylvania from February 1973 to February 2011 were reviewed in an institutional review board approved retrospective study. Of the 17 patients with tumors in the thorax, abdomen, or pelvis, 76% had local control or clinically significant symptomatic relief for at least 1 year or until death. As expected, the predominant toxicity was due to irradiation of tumor-adjacent normal tissues without clinically significant hematologic toxicity. Due to widespread systemic metastases with areas of bulky, symptomatic tumor, 5 of the 17 patients were treated with sequential 131I-MIBG (2 mCi/kg per treatment) and external beam radiotherapy to 9 sites. In these patients, all areas that were irradiated with external beam radiotherapy showed durable objective response despite all patients eventually experiencing out-of-field systemic progression requiring other treatment. Four of these patients remain alive with excellent performance status 16, 18, 23, and 24 months after external beam radiotherapy. External beam radiotherapy can be highly effective in local management of malignant paraganglioma and can be used in conjunction with 131I-MIBG due to nonoverlapping toxicities with excellent control of locally bulky tumors.
Asunto(s)
3-Yodobencilguanidina/uso terapéutico , Neoplasias de las Glándulas Suprarrenales/radioterapia , Radioisótopos de Yodo/uso terapéutico , Paraganglioma/radioterapia , Feocromocitoma/radioterapia , Adulto , Terapia Combinada , Femenino , Humanos , Masculino , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND AND STUDY AIMS: Esophageal ulcers are a rare cause of upper gastrointestinal morbidity and may be due to different etiologies. We sought to systematically evaluate patients with esophageal ulcers and describe their presentations, endoscopic findings, etiologies, treatments, and outcomes. PATIENTS AND METHODS: Patients diagnosed with esophageal ulcers over an 11-year period were retrospectively identified from our institution's electronic medical records. RESULTS: We identified 100 patients with esophageal ulcers (0.49% of patients undergoing upper endoscopy). Half of them presented due to gastrointestinal bleeding and three-quarters were admitted to the hospital. The majority were in the lower esophagus. Twenty-two unique etiologies, including multiple iatrogenic causes, were diagnosed in 91 of the cases. The most common etiology was gastroesophageal reflux disease (57%), followed by non-steroidal anti-inflammatory drug use (7%), malignancies (3%), vomiting (3%), caustic ingestion (2%), pill esophagitis (2%) and radiation (2%). Many etiologies showed a predilection for specific segments of the esophagus. Nine ulcers required endoscopic intervention and all were treated successfully. Repeat endoscopies were performed 5 times for diagnostic or "second look" reasons, none of which changed the patients' diagnosis or treatment. No patients required surgery or stricture dilation. One patient's ulcer was complicated by perforation and he subsequently died. Four other patients died from non-ulcer related causes. CONCLUSIONS: While the majority of ulcers were due to gastroesophageal reflux disease, 22 different etiologies were identified. Many were due to medication or iatrogenic causes. Repeat endoscopy did not appear to be helpful. While the incidence was low, they were frequently associated with significant morbidity.
Asunto(s)
Enfermedades del Esófago , Reflujo Gastroesofágico , Úlcera Péptica , Enfermedades del Esófago/diagnóstico , Enfermedades del Esófago/etiología , Enfermedades del Esófago/terapia , Humanos , Masculino , Estudios Retrospectivos , Úlcera/diagnóstico , Úlcera/etiología , Úlcera/terapiaRESUMEN
The incidence of obesity-related nephropathy (ORG) is increasing with the growing incidence of obesity. ORG is associated with morbid obesity, proteinuria and renal biopsy findings of focal global and segmental glomerulosclerosis (FSGS), which can be associated with significant renal impairment. Weight reduction is associated with improvement of ORG, however, conservative measures aiming at long-term weight reduction are difficult to achieve. Bariatric surgery is the most effective way of achieving long-term weight reduction. We present a case of ORG with nephrotic-range proteinuria and FSGS on renal biopsy. Following bariatric surgery, patient achieved successful weight reduction with significant decrease in proteinuria and stabilization of renal function.
Asunto(s)
Cirugía Bariátrica , Glomeruloesclerosis Focal y Segmentaria/terapia , Síndrome Nefrótico/terapia , Obesidad Mórbida/cirugía , Adulto , Femenino , Glomeruloesclerosis Focal y Segmentaria/etiología , Glomeruloesclerosis Focal y Segmentaria/patología , Humanos , Síndrome Nefrótico/etiología , Obesidad Mórbida/complicaciones , Pérdida de PesoRESUMEN
Adrenal vein sampling (AVS) is essential in differentiating unilateral from bilateral sources of aldosterone excess in primary aldosteronism (PA). However, its ability to predict blood pressure (BP) improvement after adrenalectomy has not been well studied. This is a retrospective observational study of 119 patients who underwent AVS by sequential technique followed by adrenalectomy for PA at the Hospital of the University of Pennsylvania from 1997 to 2015. Median age was 52 years (interquartile range 44-59), 67% were male and median duration of hypertension was 10 (interquartile range 6-20) years. A total of 76% and 90% of patients experienced BP improvement at 0-6 months or at any time point after surgery, respectively. Lateralization index (LI) >8, but not the presence of contralateral suppression, was significantly associated with BP improvement after surgery by multivariate logistic regression analysis adjusted for potential confounders (odds ratio (95% confidence interval): 17.1 (1.7-171.6) and 6.39 (0.06-641.8), respectively). A prediction score was created by covariates that was significantly associated with BP improvement in logistic regression analysis (duration of hypertension, body mass index, preoperative systolic BP and number of antihypertensive medications). Receiver-operating characteristic curve analyses showed that the addition of LI >8 to the score increased its ability to predict BP improvement (area under the curve 0.73-0.80). In conclusion, LI is useful in predicting improvement in BP after adrenalectomy for PA. The results of this study suggest that patients with long-standing severe hypertension may still benefit from surgery if LI >8.
Asunto(s)
Pruebas de Función de la Corteza Suprarrenal , Adrenalectomía , Presión Sanguínea , Hiperaldosteronismo/cirugía , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
This study examined the food group intake and the dietary quality of middle-aged and older Gujarati Asian Indian immigrants (45 years or older) living in two urban metropolitan areas in the U.S. Participants (90 men, 99 females) completed a 24-hour dietary recall, which was used to determine if they met the daily food group intake guidelines of the U.S. Food Guide Pyramid. The overall quality of their reported dietary intake was determined using the Healthy Eating Index based on their nutrient and food group intake. Both men and women met the daily number of servings recommendations for the grains (men: 9.3 servings/day; women: 6.9 servings/day) and vegetables (men: 4.5 servings/day; women: 3.6 servings/day) groups, but did not meet the recommendations for fruits, dairy and meats groups. The total score on the Healthy Eating Index of the diets of these participants was 73, indicative of a dietary intake that does not meet the established U.S. dietary guidelines. These immigrants should be educated about appropriate food choices (ethnic and non-ethnic) within each of the U.S. Food Guide Pyramid food groups to improve the overall quality of their dietary intakes.
Asunto(s)
Dieta/normas , Conducta Alimentaria/etnología , Política Nutricional , Fenómenos Fisiológicos de la Nutrición , Productos Lácteos , Grano Comestible , Emigración e Inmigración , Femenino , Frutas , Humanos , India/etnología , Masculino , Carne , Recuerdo Mental , Persona de Mediana Edad , Minerales , Necesidades Nutricionales , Estados Unidos , Verduras , VitaminasRESUMEN
There is little knowledge of the existence of Alzheimer disease (AD) or Alzheimer type of dementia in indigenous populations of developing countries. In an effort to evaluate this, we assessed the deposition of amyloid beta (A beta) protein and other lesions associated with AD in brains of elderly East Africans. Brain tissues were examined from 32 subjects, aged 45 to 83 years with no apparent neurological disease, who came to autopsy at two medical Institutions in Nairobi and Dar es Salaam. An age-matched sample from subjects who had died from similar causes in Cleveland was assessed in parallel. Of the 20 samples from Nairobi, 3 (15%) brains exhibited neocortical A beta deposits that varied from numerous diffuse to highly localized compact or neuritic plaques, many of which were also thioflavin S positive. Two of the cases had profound A beta deposition in the prefrontal and temporal cortices and one of these also exhibited moderate to severe cerebral amyloid angiopathy. Similarly, 2 of the 12 samples from Dar es Salaam exhibited diffuse and compact A beta deposits that were also predominantly reactive for the longer A beta 42 species compared to A beta 40. We also noted that A beta plaques were variably immunoreactive for amyloid associated proteins, apolipoprotein E, serum amyloid P and complement C3. Tau protein reactive neurofibrillary tangles (NFT) were also evident in the hippocampus of 4 subjects. By comparison, 4 (20%) of the 20 samples from randomly selected autopsies performed in Cleveland showed A beta deposits within diffuse and compact parenchymal plaques and the vasculature. These observations suggest A beta deposition and some NFT in brains of non-demented East Africans are qualitatively and quantitatively similar to that in age-matched elderly controls from Cleveland. While our small scale study does not document similar prevalence rates of preclinical AD, it suggests that elderly East Africans are unlikely to escape AD as it is known in developed countries.
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Envejecimiento , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/análisis , Encéfalo/citología , Encéfalo/patología , Anciano , Anciano de 80 o más Años , Apolipoproteínas E/análisis , Biomarcadores , Humanos , Inmunohistoquímica , Kenia , Persona de Mediana Edad , Neuritas/patología , Neuritas/ultraestructura , Ohio , Especificidad de Órganos , Células Piramidales/citología , Células Piramidales/patología , Valores de Referencia , Componente Amiloide P Sérico/análisis , TanzaníaRESUMEN
Recent advances indicate numerous molecular and cellular elements of the immune system are involved in the pathogenesis of Alzheimer's disease. Amyloid beta protein deposition induces many molecules associated with a predominantly local inflammatory response within the brain parenchyma. These responses also provoke the release of immune system mediators including cytokines, which all seem largely to be produced by reactive cells such as astrocytes and microglia. Classical acute phase proteins of the pentraxin and serine protease inhibitor (serpin) families as well as a host of complement proteins and some coagulation factor seem the most intrinsically involved. These secreted molecules display variable binding with the amyloidotic lesions. Although our understanding of the molecular specificity and significance of the interaction of these proteins within the lesions is not replete, the development of unique inhibitors of the inflammatory reactions could provide therapeutic strategies to impede the pathogenetic process. Currently, this appears a more viable option than to inhibit amyloid beta production or modify amyloid beta precursor protein processing, an approach which seems more complex.
Asunto(s)
Enfermedad de Alzheimer/inmunología , Enfermedad de Alzheimer/metabolismo , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Inflamación/inmunología , Inflamación/metabolismo , Enfermedad de Alzheimer/patología , Química Encefálica/fisiología , Humanos , Inflamación/patología , Mediadores de Inflamación/fisiologíaRESUMEN
Revascularization of renal artery stenosis for the treatment of hypertension is an established procedure. In selected clinical scenarios, successful revascularization procedures may preserve or restore renal function. We present a 31-year-old man who underwent successful renal revascularization of a solitary functioning kidney after being dialysis dependent for approximately 190 days. He had dramatic improvement of renal function and has remained off dialysis since his surgery 18 months ago. He continues to have severe but controllable hypertension.
Asunto(s)
Lesión Renal Aguda/terapia , Obstrucción de la Arteria Renal/cirugía , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/etiología , Adulto , Creatinina/sangre , Humanos , Riñón/patología , Masculino , Inducción de Remisión , Obstrucción de la Arteria Renal/complicaciones , Diálisis RenalRESUMEN
Salicylate intoxication is frequently overlooked as a cause of noncardiogenic pulmonary edema and altered mental status in adult patients. We describe a 42-year-old woman who presented with two episodes of recurrent noncardiogenic pulmonary edema requiring intubation. The first admission to hospital triggered an extensive initial workup that did not indicate a cause for the pulmonary edema. At the second presentation, recognition of the clinical syndrome in the emergency department led to the correct diagnosis of salicylate intoxication. The patient was successfully treated with hemodialysis and urinary alkalinization, leading to rapid resolution of pulmonary edema and extubation. Several aspects of the clinical presentation suggest that the patient suffers from chronic salicylism, probably complicated by episodic superimposed acute intoxication, a condition often misdiagnosed or diagnosed late in the course of disease, contributing to substantial morbidity and mortality in these patients. Maintenance of a high index of suspicion and rapid institution of appropriate therapy including hemodialysis once the diagnosis is established is an important determinant of outcome in this serious but underdiagnosed disorder.
Asunto(s)
Edema Pulmonar/inducido químicamente , Diálisis Renal , Salicilatos/envenenamiento , Acetaminofén/envenenamiento , Adulto , Analgésicos no Narcóticos/envenenamiento , Sobredosis de Droga/terapia , Femenino , Humanos , Edema Pulmonar/terapia , Salicilatos/orinaRESUMEN
The safety of gadolinium (Gd-benzyloxypropionictetra-acetate [BOPTA] dimeglumine) infusion was evaluated in 32 patients with severe or moderate chronic renal failure in a prospective, randomized, double-blind, placebo-controlled study. Renal failure was defined as severe if creatinine clearance was between 10 and 29 mL/min, and as moderate if creatinine clearance was between 30 and 60 mL/min. Serum creatinine level and 24-hour urine samples for creatinine clearance were followed up serially for 7 days after the administration of either gadolinium (Gd-BOPTA dimeglumine), 0.2 mmol/kg, or a saline infusion. No patient experienced a significant change in renal function, defined as an increase in serum creatinine level greater than 0.5 mg/dL more than baseline, and no patient required hospitalization or dialysis during the study period. Gadolinium (Gd-BOPTA dimeglumine) appears to be well tolerated in patients with moderate to severe renal failure.
Asunto(s)
Meglumina/análogos & derivados , Meglumina/efectos adversos , Compuestos Organometálicos/efectos adversos , Insuficiencia Renal/complicaciones , Medios de Contraste , Método Doble Ciego , Gadolinio , Humanos , Infusiones Intravenosas , Meglumina/administración & dosificación , Compuestos Organometálicos/administración & dosificación , Insuficiencia Renal/sangreRESUMEN
Recent advances indicate soluble amyloid beta (A beta) protein is produced constitutively during normal metabolism of the amyloid precursor protein (APP). This has not been directly examined in human brain vascular tissues. Using a panel of well-characterized antibodies, here we show that increased amounts of soluble A beta were found in isolated vascular tissues from AD subjects compared to age-matched controls without significant Alzheimer pathology. Immunocytochemical analyses of isolated vessel preparations showed characteristic transverse patterns of A beta deposits in large vessels with smooth muscle, however, fine A beta deposits were apparent even in capillaries. A proportion of such A beta protein and potentially amyloidogenic carboxyl terminal fragments were released by solubilization and disruption of the vascular basement membrane by collagenase treatments. We further demonstrated by in vitro metabolic labelling that soluble A beta or an A beta-like peptide is associated and produced by cerebral microvessels, meningeal vessels and the choroid plexus isolated postmortem from human as well as rat brain. Compared to those from young rats, cerebral microvessels from aging rats showed increased release of carboxyl terminal fragments of APP and A beta-like peptide. Our observations provide the first direct demonstration that human vascular tissues produce soluble A beta, a product of the secretory pathway in APP processing. Our findings also suggest that aging associated alterations in the basement membranes are a factor in A beta accumulation that results in vascular amyloid deposition, the principal feature of cerebral amyloid angiopathy.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular , Plexo Coroideo/irrigación sanguínea , Meninges/irrigación sanguínea , Microcirculación/metabolismo , Anciano , Envejecimiento/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/análisis , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Humanos , Immunoblotting , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Fragmentos de Péptidos/análisis , Ratas , Ratas Endogámicas F344 , Valores de ReferenciaRESUMEN
Several growth factors have been implicated in the pathogenesis of Alzheimer's disease (AD). We considered whether the vascular endothelial growth factor (VEGF) is involved in the vascular pathology associated with most cases of AD. We observed enhanced VEGF immunoreactivity in clusters of reactive astrocytes in the neocortex of subjects with AD compared to elderly controls. VEGF reactivity was also noted in walls of many large intraparenchymal vessels and diffuse perivascular deposits. In addition, we established that astrocytic and perivascular VEGF reactivity was enhanced in cerebral cortex of rats subjected to cerebral ischemia and to chronic hypoxia; experimental conditions known to be associated with astrogliosis and angiogenesis. We suggest the increased VEGF reactivity, also observed in infarcted human brain tissue, implicates compensatory mechanisms to counter insufficient vascularity or reduced perfusion (oligemia) apparent in AD.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Isquemia Encefálica/metabolismo , Factores de Crecimiento Endotelial/análisis , Linfocinas/análisis , Adulto , Anciano , Animales , Femenino , Humanos , Inmunohistoquímica , Macaca mulatta , Masculino , Persona de Mediana Edad , Ratas , Ratas Endogámicas SHR , Ratas Wistar , Lóbulo Temporal/química , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
The presence of apolipoprotein E (ApoE)-E4 allele has been implicated as a risk factor for Alzheimer's disease (AD). We examined the occurrence of ApoE 4 alleles in AD associated with cerebral amyloid angiopathy and other vascular lesions. We found significantly high frequency of the ApoE 4 allele in AD with moderate to severe CAA. The frequency of the allele was also high in AD cases with other vascular lesions such as multiple infarcts and lacunes. As previously reported, we confirm a greater frequency of the ApoE 4 allele in the diffuse Lewy body variant of AD. Our results suggest ApoE 4 allele to be a significant factor in the development of CAA in AD. While this may be related to increased brain amyloid load as a consequence of ApoE genotype, the possibility exists that ApoE may be a specific factor in vascular abnormalities associated with AD.
Asunto(s)
Alelos , Enfermedad de Alzheimer/genética , Apolipoproteínas E/genética , Angiopatía Amiloide Cerebral/genética , Trastornos Cerebrovasculares/genética , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/complicaciones , Angiopatía Amiloide Cerebral/etiología , Humanos , Inmunohistoquímica , Persona de Mediana EdadRESUMEN
Current evidence from genetic and epidemiological studies supports the view that Alzheimer's disease (AD) is a heterogeneous disorder. While the disease is pathologically defined by the presence of specified lesions in form of amyloid plaques and neurofibrillary tangles within the parenchyma, other features of pathology are often either neglected or considered coincidental. Our studies suggest that cerebrovascular pathology is inherently part of the disorder, which could be an important factor in a cause or effect manner. We have recently identified subjects having died with severe amyloid beta (A beta) protein cerebral amyloid angiopathy (CAA) in the absence of a profound Alzheimer pathology. These subjects, diagnosed with dementia had a late onset disease and were found at autopsy to exhibit severe CAA but paucity of typical AD changes. Immunocytochemical studies showed numerous microvascular abnormalities as well as characteristic degeneration of the vascular smooth muscle in both surface and intracortical vessels. The pathology was also characterized by occasional intracerebral hemorrhages and multiple infarcts. Further assessment of the abnormalities and amyloid infiltrated cerebral vessels with antibodies to the carboxyl terminus of A beta indicated that the longer, more pathogenic form of A beta(1-42) was found to be highly associated with intracerebral hemorrhages. Our observations suggest that these mild AD cases with a predominantly vascular pathology are variants of AD and bear resemblance to the familial Dutch and Flemish versions of cerebral amyloidosis. We propose that AD is a group of diseases with a variable pathology analogous to the prion diseases, in which a vascular variant also exists.
Asunto(s)
Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Angiopatía Amiloide Cerebral/patología , Anciano , Anciano de 80 o más Años , Encéfalo/patología , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Recent studies have demonstrated the deposition of amyloid beta (A beta) protein with carboxyl- and aminoterminal heterogeneity in cortical and cerebrovascular deposits of Alzheimer's disease (AD). Using carboxyl end-terminal specific antibodies to A beta peptides, we examined the immunocytochemical distribution of A beta 40 and A beta 42 species in brain tissue from a Swedish subject with familial AD (FAD) bearing the double mutation at codons 670/671 in the amyloid beta precursor protein (A beta PP), and from subjects with Down's syndrome and sporadic AD. In the Swedish subject, we found profound parenchymal A beta deposits and cerebral amyloid angiopathy in all four cortical lobes and cerebellum. A beta 42 was evident in almost all parenchymal deposits as well as many vascular deposits. Although A beta 40 was present in meningeal and intraparenchymal vessels, deposits containing this shorter peptide reactivity were sparse. Surprisingly, our observations in Swedish FAD showing a remarkable abundance of A beta 42 in both parenchymal and vascular deposits were qualitatively similar to the Down's syndrome and most sporadic AD cases, and to previously published A beta PP717 FAD. While previous transfection studies in different cell cultures indicate substantially increased soluble A beta production and A beta 40 species to be predominant, it would appear that the double A beta PP mutations in Swedish FAD largely result in the deposition of the longer A beta 42 in vivo.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/análisis , Corteza Cerebral/química , Circulación Cerebrovascular/fisiología , Síndrome de Down/metabolismo , Proteínas del Tejido Nervioso/análisis , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/genética , Precursor de Proteína beta-Amiloide/genética , Síndrome de Down/genética , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Mutación , Proteínas del Tejido Nervioso/genética , Periodicidad , SueciaRESUMEN
Axoplasmic organelles obtained from the squid giant axon move on actin filaments at an average velocity of 1 microm/s [Nature 356 (1992) 722]. The unconventional myosins, in particular, the myosin-V class of motor proteins, represent the most likely candidates to have a role in this motility. Experiments were performed to determine whether a member of the myosin-V class of unconventional myosins is present in axoplasm and optic lobes. Western blots of axoplasm probed with an affinity purified antibody to chicken brain myosin-V (CBM-V) showed cross-reactivity with a protein of Mr 196 kD (p196) which was subsequently purified from squid optic lobes using a modification of a protocol for the purification of CBM-V [Methods Enzymol. 298 (1998) 3; Cell 75 (1993) 215]. Western blots of CBM-V probed with an alpha-p196 polyclonal IgG showed cross-reactivity with CBM-V. Purified p196 has been found to be a calmodulin (CaM) binding protein that possesses calcium-stimulated actin-activated ATPase activity. Equilibrium density fractionation of motile axoplasmic organelle preparations has revealed that p196 cosedimented with the peak organelle fraction into Percoll gradients in the presence of cytochalasin B and ATP. Based on this evidence, we conclude that the p196 present in axoplasm and purified from optic lobes is a squid homolog of CBM-V and functions as a motor for fast transport of membranous organelles on actin filaments in neurons.