Search PubMed⌕ Search

Biomedical subjects

R L Hamilton

Publications and source records attributed to R L Hamilton.

At least 19 recordsLinked to original sources
PubMed2006

Lewy bodies in the amygdala increase risk for major depression in subjects with Alzheimer disease.

OBJECTIVE: To determine the relationship between major depression and the presence of Lewy bodies (LBs) in patients with Alzheimer disease (AD). METHODS: The authors examined the presence of major depression in 267 pathologically diagnosed AD cases with Mini-Mental State Examination (MMSE) scores >9. LBs were identified in 142 (53%) patients using alpha-synuclein immunohistochemistry. Subjects were classified according to the Consensus Guidelines for the Clinical and Pathologic Diagnosis of Dementia with LB: 1 to 2 (n = 21), 3 to 6 (n = 26), and 7 to 10 (n = 69). Twenty-six patients had LB only in the amygdala. All cases with LB scores 7 to 10 (or cortical) had amygdala LBs. The association between LBs and major depression was examined with logistic regression analyses, controlled for age at study entry, education level, MMSE scores, antidepressant use, follow-up time, and the presence of cerebrovascular disease. RESULTS: Major depression was present in 11 (9%) AD alone cases, and in 25 (18%) of the AD + LBs cases; amygdala: 8 (31%), scores 1 to 2: 1 (5%), scores 3 to 6: 3 (11.5%), and scores 7 to 10: 13 (14%). Major depression was associated with LBs, in general (relative risk [RR] = 3.06, 95% CI: 1.25 to 7.46), with amygdala only LBs (RR = 8.56 (95% CI: 1.83 to 40.3), and with LB scores 7 to 10 (RR = 3.83, 95% CI: 1.33 to 11.0). There was an association between all amygdala LBs cases (amygdala only LBs + LB scores 7 to 10) and major depression (RR = 4.77, 95% CI: 1.78 to 12.7), but no association was noted between LBs and depression in the absence of amygdala LBs (RR = 0.96, 95% CI: 0.46 to 1.06). CONCLUSION: Lewy bodies (LBs) in the amygdala and in cortical areas increase the risk for major depression in Alzheimer disease. What is common in these two groups is the presence of LBs in the amygdala. That is, all of the cases with cortical LBs also had LBs in the amygdala, making this region the critical area for the development of depression.

Aged↗
PubMed2005

Genetic association between the APOE*4 allele and Lewy bodies in Alzheimer disease.

OBJECTIVE: To explore the association between APOE*4 and pathologically confirmed cases of the Lewy body (LB) variant of Alzheimer disease (AD). METHODS: With use of alpha-synuclein (AS) immunohistochemistry, LBs were detected in 74 of 131 (56.5%) of the AD + LB cases; the remaining 57 cases (43.5%) did not have LBs. RESULTS: There were no differences in gender or age between Caucasian subjects with AD + LB or AD alone or control subjects. The APOE*4 allele frequency was highest in the AD + LB group (47.3%; 95% CI = 37.8 to 57.0%), intermediate in the AD-alone group (35.1%; 95% CI = 25.3 to 46.3%), and lowest in the control group (14.2%; 95% CI = 10.5 to 18.9%). With use of logistic regression analysis, the odds of having AD + LB vs AD alone were 2.1-fold (95% CI = 1.0 to 4.5, p = 0.055) greater in persons with an APOE*4 allele than in those without an APOE*4 allele. CONCLUSION: The APOE*4 allele is associated with the presence of concomitant Lewy bodies in Alzheimer disease.

Age of Onset↗
PubMed2004

Right prosubiculum amyloid plaque density correlates with anosognosia in Alzheimer's disease.

BACKGROUND: Anosognosia is a common manifestation of Alzheimer's disease. There is an association between impaired awareness and frontal-executive cognitive deficits. Anosognosia is also correlated with decreased metabolism in the right hemisphere, particularly in frontal lobe regions. OBJECTIVE: To investigate pathological correlates of anosognosia in Alzheimer's disease. DESIGN: 41 subjects followed longitudinally in the University of Pittsburgh memory disorders clinic and with necropsy verified Alzheimer's disease were divided into two groups, based on previous clinical assessment: +Aware (n = 23) and -Aware (n = 18). A subset analysis matching subjects for dementia severity using mini-mental state examination scores was also carried out (13 +Aware; 13 -Aware). Histopathological data from necropsy brain tissue consisted of senile plaque (SP) and neurofibrillary tangle (NFT) counts (regional density) from four different brain regions in the right and left hemispheres: superior and middle frontal gyri (SMF), superior temporal isocortex (ST), the prosubiculum of the hippocampus (PRO), and the entorhinal cortex (EC). RESULTS: SP density was greater in the right PRO region of -Aware subjects (F = 6.54, p = 0.015) than +Aware subjects. Significant differences between SP or NFT density were not observed in any other regions. In the subset analysis matching for dementia severity, SP density was again greater in the right PRO region of -Aware subjects than in the other regions (F = 12.72, p = 0.002). CONCLUSIONS: Increased SP density in the right PRO region suggests that selective pathological involvement of this area contributes to awareness deficits in Alzheimer's disease. The putative role of the PRO in self appraisal may reflect its interconnections with other medial temporal and prefrontal regions.

Aged↗
PubMed2001

Age and TP53 mutation frequency in childhood malignant gliomas: results in a multi-institutional cohort.

Malignant astrocytoma is one of the most deadly primary central nervous system tumors. Although significant progress has been made in understanding the molecular pathways that lead to the development of these tumors in adults, comparatively little analysis has been done in childhood astrocytomas, which are less common and have a more favorable prognosis. Our previous studies of an institutional cohort of children with malignant gliomas suggested the existence of distinct molecular pathways of tumorigenesis in younger versus older children, based on the finding of a high frequency of TP53 mutations in tumors from children >3 years of age at diagnosis, compared with those from younger children. In the current study, the association between TP53 mutations and age was examined in greater detail using the multi-institutional group of children enrolled in Children's Cancer Group Study 945, the largest cohort of childhood high-grade gliomas analyzed to date. Seventy-seven tumors with centrally reviewed diagnoses of anaplastic astrocytoma or glioblastoma multiforme had sufficient archival histopathological material for microdissection-based genotyping. Sections were examined histologically, and topographic targets that contained malignant tissue were isolated by microdissection and subjected to PCR-based amplification and sequencing of TP53 exons 5-8. Twenty-six tumors (33.8%) had mutations in those exons. Mutations were observed in 2 of 17 tumors (11.8%) from children <3 years of age at diagnosis versus 24 of 60 tumors (40%) from older children, a difference that was statistically significant (P = 0.04), in agreement with our previous results. Whereas malignant gliomas in older children have a frequency of mutations comparable to tumors that arise in young adults, those from children <3 years old do not. The association between age and frequency of TP53 mutations among pediatric malignant gliomas indicates the probable existence of two distinct pathways of molecular tumorigenesis in younger versus older children.

Adolescent↗
PubMed2001

Alterations of striatal dopamine receptor binding in Alzheimer disease are associated with Lewy body pathology and antemortem psychosis.

BACKGROUND: Lewy bodies (LB) are present in at least 20% to 30% of persons with Alzheimer disease (AD) and contribute to the risk of psychosis and to excess cognitive burden. OBJECTIVE: To determine whether altered striatal dopamine receptor binding is associated with LB and psychosis in AD. DESIGN: Postmortem case control. SETTING: Alzheimer's Disease Research Center at the University of Pittsburgh (Pa). PARTICIPANTS: Consecutive cases from the Alzheimer's Disease Research Center brain bank, neuroleptic free for at least 1 month prior to death, with neuropathologic diagnoses of AD with LB (AD + LB, n = 14), AD without LB (AD, n = 13), or normal brains (n = 8). MAIN OUTCOME MEASURES: Dopamine D1, D2, and D3 receptor densities, and affinities as determined by selective saturation binding studies in striatal tissue. RESULTS: Subjects with AD + LB, compared with those with AD, demonstrated increased D1 receptor density and decreased D2 and D3 receptor density. D3 receptor density was selectively increased, however, in AD subjects with a history of psychosis, independent of the presence or absence of LB. The effect of neuroleptic treatment on D3 binding was further examined in an additional group of subjects who had received neuroleptics near the time of death. Neuroleptic treatment reduced D3 affinity with no effect on D3 density. CONCLUSIONS: Alzheimer disease with LB is associated with selective alterations in dopamine receptor density, which may contribute to the distinct clinical profile of this group. The D3 receptor may be an important target of neuroleptic treatment of psychosis in AD.

Aged↗
PubMed2001

Brain membrane phospholipid alterations in Alzheimer's disease.

Studies have demonstrated alterations in brain membrane phospholipid metabolite levels in Alzheimer's disease (AD). The changes in phospholipid metabolite levels correlate with neuropathological hallmarks of the disease and measures of cognitive decline. This 31P nuclear magnetic resonance (NMR) study of Folch extracts of autopsy material reveals significant reductions in AD brain levels of phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns), and elevations in sphingomyelin (SPH) and the plasmalogen derivative of PtdEtn. In the superior temporal gyrus, there were additional reductions in the levels of diphosphatidylglycerol (DPG) and phosphatidic acid (PtdA). The findings are present in 3/3 as well as 3/4 and 4/4 apolipoprotein E (apoE) genotypes. The AD findings do not appear to reflect non-specific neurodegeneration or the presence of gliosis. The present findings could possibly contribute to an abnormal membrane repair in AD brains which ultimately results in synaptic loss and the aggregation of A beta peptide.

Aged↗
PubMed2001

Histopathologic response of the immature rat to diffuse traumatic brain injury.

The purpose of this study was to characterize the histopathologic response of rats at postnatal day (PND) 17 following an impact-acceleration diffuse traumatic brain injury (TBI) using a 150-g/2-meter injury as previously described. This injury produces acute neurologic and physiologic derangements as well as enduring motor and Morris water maze (MWM) functional deficits. Histopathologic studies of perfusion-fixed brains were performed by gross examination and light microscopy using hematoxylin and eosin, Bielschowsky silver stain, and glial fibrillary acidic protein (GFAP) immunohistochemistry at 1, 3, 7, 28, and 90 day after injury. Gross pathologic examination revealed diffuse subarachnoid hemorrhage (SAH) at 1-3 days but minimal supratentorial intraparenchymal hemorrhage. Petechial hemorrhages were noted in ventral brainstem segments and in the cerebellum. After 1-3-day survivals, light microscopy revealed diffuse SAH and intraventricular hemorrhage (IVH), mild edema, significant axonal injury, reactive astrogliosis, and localized midline cerebellar hemorrhage. Axonal injury most commonly occurred in the long ascending and descending fiber tracts of the brainstem and occasionally in the forebrain, and was maximal at 3 days, but present until 7 days after injury. Reactive astrocytes were similarly found both in location and timing, but were also significantly identified in the hippocampus, white matter tracts, and corpus callosum. Typically, TBI produced significant diffuse SAH accompanied by cerebral and brainstem astrogliosis and axonal injury without obvious neuronal loss. Since this injury produces some pathologic changes with sustained functional deficits similar to TBI in infants and children, it should be useful for the further study of the pathophysiology and therapy of diffuse TBI and brainstem injury in the immature brain.

Age Factors↗
PubMed2001

Regional dependence of cerebral reperfusion after circulatory arrest in rats.

The severity of neurologic dysfunction after circulatory arrest depends on cerebral reperfusion during and after resuscitation. The objective of current study was to investigate the temporal and spatial patterns of the cerebral perfusion immediately after resuscitation. Precise control of circulatory arrest was achieved in rats by combination of asphyxia and transient blockage of cardiac-specific beta-adrenergic receptors with esmolol, an ultra-short-acting beta-blocker. Animals were randomized into 3 groups with resuscitation starting 0.5 (sham group, no asphyxia, n = 5), 4 (Group 2, n = 5), or 12 minutes (Group 3, n = 8) later by retrograde intraarterial infusion of donor blood along with a resuscitation mixture. Cerebral perfusion was measured by magnetic resonance imaging (MRI) using arterial spin labeling. The average perfusion before arrest was 163 +/- 27 mL 100 g(-1) min(-1) under isoflurane anesthesia. Resuscitation led to transient perfusion increase, which started from thalamus and hypothalamus and later shifted to the cortex. Severe hypoperfusion to as low as 6% to 20% of the normal level developed in the first 10 to 20 minutes of reperfusion and lasted for at least 2 hours. On the fifth day after circulatory arrest, all animals showed a normal level of perfusion (159 +/- 57 mL 100 g(-1) min(-1) ) and minimal neurologic deficit. Nevertheless, histologic examination revealed extensive changes in the CA1 region of the hippocampus consistent with global ischemia and reperfusion damage. The combination of an improved circulatory arrest model and noninvasive MRI cerebral perfusion measurements provides a powerful tool for investigations of circulatory arrest and resuscitation, allowing for evaluation of therapies aimed at modulating cerebral reperfusion.

Animals↗
PubMed2001

Congenital reactive myofibroblastic tumor of the petrous bone: case report.

OBJECTIVE AND IMPORTANCE: Myofibroblastic tumors are members of a diverse spectrum of neoplastic and quasineoplastic lesions that occur most commonly during childhood and typically involve soft tissues. We present a case of a congenital reactive myofibroblastic tumor of the petrous bone (i.e., cranial fasciitis) that was successfully treated with surgical excision. CLINICAL PRESENTATION: A newborn girl with congenital right facial palsy and deafness was noted during imaging evaluation to have a large enhancing mass that was destroying the right petrous bone and extending into the posterior and middle cranial fossae. INTERVENTION: After embolization, an open biopsy was performed, which revealed a moderately cellular, spindle cell neoplasm without mitosis or necrosis, with scattered lymphocytes, eosinophils, and multinucleated giant cells. The spindle cells demonstrated strong immunoreactivity for vimentin, muscle-specific actin, and alpha-smooth muscle actin, with prominent reticulin staining between individual cells. Staining for CD68, a histiocyte marker, was positive within the multinucleated giant cells and many of the spindle cells; CD34, S-100, and desmin staining was absent. On the basis of these findings, the lesion was classified as a reactive myofibroblastic tumor, consistent with a cranial variant of nodular fasciitis. Because of the large size and significant mass effect of the tumor, a resection was performed several days later, using a combined supra- and infratentorial approach. Dense adherence of the mass to the walls of the sigmoid sinus and the carotid artery precluded complete resection without sacrifice of these vessels, which was not performed because of the known potential of these tumors to remain stable or regress after extensive subtotal resection. The presumed residual tumor subsequently regressed, and the patient has exhibited no detectable residual disease in 2 years of follow-up monitoring. CONCLUSION: Reactive myofibroblastic tumors of the calvarium are uncommon lesions that superficially resemble sarcomas. Recognition of this diagnostic entity is important, to avoid unnecessary treatment with intensive adjuvant therapy. Although the management of these tumors relies predominantly on surgical resection, surgical decision-making should take into account the fact that small areas of residual disease can regress spontaneously.

Bone Neoplasms↗
PubMed2001

Sudden death from fulminant acute cerebellitis.

Acute cerebellitis is postulated to result from viral and/or autoimmune etiologies. This disease has been reported to have a variable course. We report a case of sudden death from acute fulminant cerebellitis in a 13-year-old ballet dancer. Serial CT and MRI demonstrated rapid progression of the disease. Histopathologic correlation is provided. The etiologies, clinical course, therapeutic interventions and postmortem evaluation of this potentially life-threatening condition are briefly reviewed.

Acute Disease↗
PubMed2001

Composition and ultrastructure of size subclasses of normal human peripheral lymph lipoproteins: quantification of cholesterol uptake by HDL in tissue fluids.

Peripheral lymph lipoproteins have been characterized in animals, but there is little information about their composition, and none about their ultrastructure, in normal humans. Therefore, we collected afferent leg lymph from 16 healthy males and quantified lipids and apolipoproteins in fractions separated by high performance-size exclusion chromatography. Apolipoprotein B (apoB) was found almost exclusively in low density lipoproteins. The distribution of apoA-I, particularly in lipoprotein A-I (LpA-I) without A-II particles, was shifted toward larger particles relative to plasma. The fractions containing these particles were also enriched in apoA-II, apoE, total cholesterol, and phospholipids and had greater unesterified cholesterol-to-cholesteryl ester ratios than their counterparts in plasma. Fractions containing smaller apoA-I particles were enriched in phospholipid. Most apoA-IV was lipid poor or lipid free. Most apoC-III coeluted with large apoA-I-containing particles. Electron microscopy showed that lymph contained discoidal particles not seen in plasma. These findings support other evidence that high density lipoproteins (HDL) undergo extensive remodeling in human tissue fluid. Total cholesterol concentration in lymph HDL was 30% greater (P < 0.05) than could be explained by the transendothelial transfer of HDL from plasma, providing direct confirmation that HDL acquire cholesterol in the extravascular compartment. Net transport rates of new HDL cholesterol in the cannulated vessels corresponded to a mean whole body reverse cholesterol transport rate via lymph of 0.89 mmol (344 mg)/day.

Adult↗
PubMed2000

Research evaluation and diagnosis of probable Alzheimer's disease over the last two decades: I.

OBJECTIVE: To describe the experience of a research clinic diagnosing AD during the last two decades, with special emphasis on patients who meet the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable AD, their patterns of clinical presentation, and neuropathologic outcomes. BACKGROUND: Probable AD has a heterogeneous clinical presentation, and can occur in the context of complicating factors. There are few reports, and none with this large of a sample, about the pattern of presentation, the nature of comorbidities, and the sensitivity and specificity of diagnosis. RESULTS: The AD Research Center of Pittsburgh examined 1139 patients with probable AD between April 1983 and February 2000. Of these 1139 probable AD patients, 29 (2.5%) had slow progression, 27 (2%) had rapid progression, 70 (6%) had an atypical presentation, and 85 (7%) had coexistent cerebrovascular disease. Confluent periventricular white matter lesions were found in 348 (30.5%) patients with probable AD. The overall sensitivity for the diagnosis of AD was 97% and the specificity 80%. However, the accuracy for the diagnosis of AD varied over the years: from 1983 to 1989, the sensitivity was 94% and specificity 52%, and from 1990 to 2000, the sensitivity was 98% and specificity 88%. CONCLUSION: Although the diagnosis of probable AD has been used to indicate the presence of a homogeneous clinical entity, these patients can vary in presentation, onset, or clinical course. This finding is of particular importance for the understanding of the pathophysiologic basis of the disease, and for the better identification of responders to dementia treatments. Although the sensitivity for the diagnosis of AD remained above 90% over the last two decades, the specificity increased, reflecting progressive improvement in the diagnosis of other dementing disorders.

Aged↗
PubMed2000

Research evaluation and diagnosis of possible Alzheimer's disease over the last two decades: II.

OBJECTIVE: To describe the experience of a research clinic diagnosing possible AD during the last two decades. BACKGROUND: The National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for possible AD are generally used to indicate that a patient has AD in association with another disease process that could by itself cause dementia. There are no studies describing how these criteria should be applied, and there are no descriptions of functional and cognitive progression or survival in possible AD. METHODS: The authors examined the clinical characteristics of 267 patients diagnosed with possible AD at the AD Research Center of Pittsburgh from 1983 to 2000 and the likelihood of arriving at four endpoints: Mini-Mental State Examination score of </= 9, Blessed Dementia Rating Scale for activities of daily living score of >/= 12, nursing home admission, and death. RESULTS: The possible AD classification has been simplified in six categories: possible AD with cerebrovascular disease (CVD) (69%), with history of alcohol abuse (15%), with history of depression (7%), with thyroid disease (4%), with history of head trauma (6%), with vitamin B12 deficiency (6%), and with other disease process that may have affected the clinical presentation of AD (4%). The presence of CVD, history of alcohol abuse, and history of depression concomitant with the onset of dementia were associated with time to death. Neither thyroid disease, history of head trauma, nor vitamin B12 deficiency were associated with any of the four endpoints. CONCLUSION: This cohort showed that comorbid conditions that can affect cognition delineate clearly defined subgroups in AD. The presence of environmental or other brain disorders sufficient to produce dementia appears to affect physical survival in patients with AD, but not functional and cognitive decline or institutionalization.

Aged↗
PubMed2000

Predictors of progression in patients with AD and Lewy bodies.

OBJECTIVE: To examine the differences in the pattern of progression between AD and AD with Lewy bodies (AD+LB). METHODS: The authors examined predictors of functional and cognitive disability, institutionalization, and death, as well as time to the development of psychosis (e.g., delusions, hallucinations), extrapyramidal signs (EPS), diurnal hypersomnia, and depression in 185 patients with definite AD and 60 with autopsy-confirmed AD+LB. In addition, they analyzed a selected group of patients who did not have comorbid systemic or CNS disease that may have affected progression of the disease (AD = 98 versus AD+LB = 44). The mean follow-up was 58.91 +/- 35.2 months. RESULTS: All cases: Patients with AD+LB had faster time to the development of EPS and diurnal hypersomnia, but not to the development of psychosis or depression. The rate of cognitive and functional decline, time to institutionalization, and physical survival was not different between AD+LB and AD. Selected cases: Patients with AD+LB developed earlier EPS and diurnal hypersomnia than AD patients, and there was a trend to develop earlier major depression, but no differences were noted in time to psychosis. Patients with AD+LB had a faster time to institutionalization than those with AD. The rate of cognitive and functional decline and physical survival was not different between AD+LB and AD in these selected cases. CONCLUSION: Patients with AD+LB can develop EPS and diurnal hypersomnia earlier and have faster time to institutionalization than those with AD alone, but cognitive and functional decline and physical survival are similar between these two entities.

Aged↗
PubMed2000

Severity of cognitive impairment and the clinical diagnosis of AD with Lewy bodies.

OBJECTIVE: 1) To examine the clinical differences between AD and AD with Lewy bodies (AD+LB); and 2) to determine the accuracy of Consensus guidelines for the clinical diagnosis of dementia with Lewy bodies (DLB) at different levels of dementia severity. METHODS: The authors examined the clinical characteristics of 185 patients with pathologically diagnosed AD alone and 60 with AD+LB. The relationship between clinical symptoms and AD+LB was determined by multivariate analyses, controlled by age, duration of symptoms, presence of cerebrovascular disease, and dementia severity. RESULTS: Mild dementia syndrome: No specific clinical symptom was associated with the presence of AD+LB. The sensitivity of the diagnosis of DLB was 62% and specificity was 54%. Moderate dementia syndrome: Extrapyramidal signs (EPS), especially cogwheel rigidity, and major depression were associated with AD+LB. The sensitivity for DLB was 82% and specificity was 31%. Severe dementia syndrome: Cogwheel rigidity and diurnal hypersomnia were associated with AD+LB. The sensitivity for DLB was 93% and specificity was 16%. CONCLUSIONS: The presence of EPS is not useful in differentiating AD+LB from AD in patients with mild dementia. However, as the disease progressed, they emerge as defining features, especially cogwheel rigidity. The accuracy of AD+LB diagnosis varies according the severity of the dementia syndrome. The low sensitivity and specificity in AD+LB patients with mild dementia suggest that in early stages AD+LB patients do not present the clinical characteristics of DLB. By contrast, the high sensitivity and low specificity for the diagnosis of DLB in moderate/severe dementia stages suggests that AD patients can also have characteristic symptoms of DLB. These results indicate that the antemortem diagnosis of AD+LB is difficult in all dementia stages, and better clinical and biologic differentiations of these entities are needed.

Aged↗
PubMed2000

Psychotic symptoms in Alzheimer's disease are not associated with more severe neuropathologic features.

Psychotic symptoms in Alzheimer's disease (AD) have been associated with increased rates of cognitive impairment and functional decline. Prior studies have been conflicting with regard to whether AD patients with psychosis (AD+P) have evidence of more severe neuropathologic findings at postmortem exam. We examined the severity of neuritic plaques and neurofibrillary tangles in six brain regions--middle frontal cortex, hippocampus, inferior parietal cortex, superior temporal cortex, occipital cortex, and transentorhinal cortex-in 24 AD+P subjects and 25 matched AD subjects without psychosis (AD-P). All analyses controlled for the presence of cortical Lewy bodies, and corrected for multiple comparisons. We found no significant associations between neuritic plaque and neurofibrillary tangle severity and AD+P, and no significant associations with any individual psychotic symptom. The association of AD+P with a more rapidly progressive course of AD appears to be mediated by a neuropathologic process other than increased severity of plaque and tangle formation.

Aged↗
PubMed2000

Resistance to diet-induced hypercholesterolemia and gallstone formation in ACAT2-deficient mice.

The importance of cholesterol ester synthesis by acyl CoA:cholesterol acyltransferase (ACAT) enzymes in intestinal and hepatic cholesterol metabolism has been unclear. We now demonstrate that ACAT2 is the major ACAT in mouse small intestine and liver, and suggest that ACAT2 deficiency has profound effects on cholesterol metabolism in mice fed a cholesterol-rich diet, including complete resistance to diet-induced hypercholesterolemia and cholesterol gallstone formation. The underlying mechanism involves the lack of cholesterol ester synthesis in the intestine and a resultant reduced capacity to absorb cholesterol. Our results indicate that ACAT2 has an important role in the response to dietary cholesterol, and suggest that ACAT2 inhibition may be a useful strategy for treating hypercholesterolemia or cholesterol gallstones.

Animals↗