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Background: Alzheimer's disease (AD) features perturbed brain glucose utilization, which could contribute to brain bioenergetic failure. This led some to consider using ketone bodies to enhance AD brain bioenergetics and treat AD., Objective: We evaluated the rate at which brain homogenates from persons with Alzheimer's disease (AD) metabolize D-β-hydroxybutyrate (BHB)., Methods: We homogenized pieces of temporal cortex from frozen autopsy brains obtained from recently deceased AD subjects ( n  = 4), and age-matched subjects that did not have clinical AD ( n  = 3). Measuring the rate of CO2 production that followed the introduction of radiolabeled BHB to the homogenates yielded a BHB utilization rate., Results: Compared to the control homogenates, the BHB-supported CO2 production rate was 66%lower in the AD homogenates ( p  < 0.05)., Conclusions: AD brains can utilize BHB, albeit less robustly than control brains. In conjunction with a previous study that demonstrated reduced glucose utilization in AD brain homogenates, our BHB data provide further evidence of AD brain mitochondrial dysfunction or altered mitochondrial biology., Competing Interests: The authors have no conflict of interest to report., (© 2021 – The authors. Published by IOS Press.)

Alzheimer's disease (AD) is the major cause of dementia, accounting for 50% to 70% of the late-onset patients, with 17 to 20 million affected. It is characterized by neurofibrillary tangles, neuronal loss, and amyloid plaques in tissues of the cortex, hippocampus, and amygdala. Apoptosis or programmed cell death appears in the progression of AD. In this study, we investigated the gene expression of 14 apoptotic genes (E2F1, p21/WAF, ICE-LAP3, Fas Antigen, CPP-32, GADD153, ICE-beta, c-Fos, c-Jun, Bax-alpha, Bcl-2, Bcl-(x)L, BAK, and p53) in 5 normal and 6 AD human hippocampal tissues, using reverse transcription-polymerase chain reaction. Our results show an upregulation of gene expression in AD patients for c-Fos and BAK. ICE-beta, c-Jun, Bax-alpha, Bcl-x(L), p53, and GADD153 were found to be upregulated in some AD samples but were not detected or downregulated in other AD or normal samples. No gene expression was found for E2F1 , p21/WAF, ICE-LAP3, Fas Antigen, CPP32, or Bcl-2. These results indicate significant increases in c-Fos , c-Jun, and Bak; therefore, we suggest that these genes may be critical in the apoptotic cascades of AD.

Background: Manganese-dependent superoxide dismutase (MnSOD) is a major defense mechanism against potential cellular damage by reactive oxygen species (ROS). We have reported increased lipid peroxidation and decreased Cu/Zn SOD enzymatic activity in the temporal cortex of Alzheimer's diseased (AD) brains., Material/methods: We now report the expression of MnSOD in the hippocampus of AD (n=8) and non-AD patients (n=7) via immunohistochemical methods, in both neuronal and non neuronal cells. We tested the hypothesis that there is differential expression of MnSOD in the CA1, CA2/3, and CA4 region of the hippocampus which may account for the neuronal loss seen in Alzheimer's disease. For neuronal cells, profile counts were made and expressed as positive neuronal profiles (MnSOD-IR) per mm(2) within hippocampal regions CA1, CA2/3, and CA4., Results: The AD MnSOD-IR counts were over 9-fold higher in the CA2/3 region (p<0.001) and over 11-fold higher in the CA4 (p<0.001) region when compared to non-AD samples. The CA1 region in the AD samples showed the smallest increase (3-fold; p<0.05) when compared to non-AD patients., Conclusions: Since the CA1 region in AD is the most severely affected by the disease, our results suggest that normal compensatory mechanisms may be insufficient to protect this region from free radical oxidative damage.

Permeable reactive barriers (PRBs), such as the Waterloo Funnel and Gate System, first implemented at Canadian Forces Borden facility in 1992, are a passive remediation technology capable of controlling the migration of, and treating contaminated groundwater in situ. Most of the PRBs installed to date have been shallow installations created by backfilling sheet-pile shored excavations with iron filing reactive media. More recently continuous trenchers [R. Puls, Installation of permeable reactive barriers using continuous trenching equipment, Proceedings of the RTDF Permeable Barriers Work Group, Virginia Beach, VA, September 1997] and Caissons [J. Vogan, Caisson installation of a pilot scale, permeable reactive barrier in situ treatment zone at the Sommersworth Landfill, NH, Presented to the RTDF Permeable Barriers Work Group, Alexandria, VA, April 1996], and vertical fracturing emplacements [G. Hocking, Vertical hydraulic fracture emplacement of permeable reactive barriers, Progress Report delivered to the Permeable Reactive Barriers Workgroup of the Remedial Technology Development Forum, Beaverton, OR, April 1998] have been used to create reactive barriers in soil. None of the prior methods are capable of adequately addressing groundwater contamination in deep and fractured bedrock aquifers. The purpose of the RSF pilot study was to install reactive media into an impacted bedrock aquifer, and to evaluate the effectiveness of in situ treatment of chlorinated volatile organic compounds (CVOCs) and metals in that type of aquifer. Three discrete fractures were identified and treated and were subjected to testing before and after treatment. Between 300 and 1700 lb. of 1 mm diameter reactive proppants were injected into each zone to facilitate treatment. Monitoring data obtained from adjacent observation wells verified that fracking fluids reached at least 42 ft from the treatment well following hydrofracturing. The concentrations of many of the CVOCs decreased up to 98% based on the results of pre- and post-RSF treatment analyses. Consistent with other research, concentrations of CVOCs were noted to decrease including trichloroethene (TCE), tetrachloroethene (PCE), 1,1,1-trichloroethane (1,1,1-TCA), 1, 1-dichloroethane (1,1-DCA), and 1,1-dichloroethene (1,1-DCE) and increases were noted in concentrations of cis-1,2-dichloroethene (cis-1,2-DCE) and chloroform suggesting that the rate of transformation of the parent compounds to these daughter products is higher than the rate of destruction of the daughter products. The RSF pilot study demonstrated that: (1) zero valent iron foam proppants have the physical and chemical properties necessary to effectively treat CVOCs and metals in groundwater when inserted under high pressures into fractured bedrock. (2) Iron foam reactive media can be placed in bedrock using high pressure hydraulic fracturing equipment and polysaccharide viscosifiers. (3) The extent of the treatment can be monitored in situ using tracers and pressure transducers. (4) Well capacity is increased by improving hydraulic conductivity through hydraulic fracturing and proppant injection. The approximate cost of all of the effort expended in the pilot study was about US$200,000. Full-scale implementations are projected to cost between US$100,000 and US$1,000,000 and would depend on site specific conditions such as the extent and level of impacted groundwater requiring treatment. This technology can potentially be implemented to create treatment zones for the passive treatment of CVOC and metal impacted groundwater in fractured rock aquifers offering a cost-effective alternative to a pump and treat forever scenario.

Apoptosis, or programmed cell death, has been proposed as a mechanism of neuropathology in Alzheimer's disease (AD). Activation of immediate early genes (IEG) c-jun and c-fos appears to be required for the initiation of apoptosis. Furthermore, the expression of c-jun is induced in cultured neurons that undergo beta-amyloid-mediated apoptosis suggesting a direct role for c-jun in the apoptosis of AD neurons. Using immunohistochemical methods, we calculated the average number of neuronal profiles per unit area expressing c-Jun and c-Fos within hippocampal regions CA1, CA2/3, and CA4 in postmortem brain samples from AD patients and age-matched non-AD patients. There was an increase in c-Jun-positive and c-Fos-positive neuronal profile density in nearly all AD hippocampal regions examined. In cerebellum there was no evidence of apoptosis as determined by using TUNEL technique, and negligible c-Jun labeling.

The overall peroxidation activity in brain tissue by region from patients with Alzheimer's disease (AD) and age-matched controls was determined employing the thiobarbituric acid-reactive substances (TBARS) assay, a measure of lipid peroxidation, followed by a determination the activities of the antioxidant enzymes Cu/Zn superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), in the frontal, temporal, and cerebellar cortex of 10 AD and 9 control brains. The level of TBARS was elevated in all regions, with particular statistical significance in the temporal cortex when compared to age-matched controls. SOD activity was significantly decreased in AD frontal and AD temporal cortex, while catalase activity was significantly decreased in AD temporal cortex. There was no significant difference in GSH-Px activity found in any of the regions examined. This study supports the theory that in AD the brain is affected by increased oxidative stress which, when combined with a decrease in SOD activity, produces oxidative alterations, seen most significantly in temporal cortex in AD, where the pathophysiologic changes are most severe.

We studied brain glucose metabolism in patients with Alzheimer's disease and age-matched controls in vivo by PET and assessed brain glucose utilization and the phosphorylation constant K3 for hexokinase. In addition we determined in vitro the binding of 2DG and measured its phosphorylation to 2DG-phosphate in cerebral microvessels obtained at autopsy from subjects with Alzheimer's disease and age-matched controls. In patients with Alzheimer's disease we found a marked decrease in the kinetic constant K3 for the hexokinase, and a marked decrease in the overall metabolism of glucose in our PET studies; in microvessels there was a marked decrease in the affinity of 2DG and a decrease in hexokinase activity. Alzheimer's disease may be related to a complex alteration in brain glucose metabolism.

Circulating growth hormone, insulin, C-peptide, and glucose levels were compared during the sleep state in adults with acromegaly and healthy control subjects. Growth hormone secretion was episodic in both groups, with the sleep-related growth hormone peak noticeably absent in the acromegalic subjects. The mean nocturnal plasma insulin concentration was greater in the acromegalics. There was no significant difference in the C-peptide between the two groups. Insulin and glucose levels did not show an early morning rise in either acromegalics or healthy subjects. The authors conclude that there is a marked difference in the circulating levels of growth hormone and insulin between the acromegalic and the healthy groups during the sleep state, and there is no sleep-related nocturnal growth hormone peak in the acromegalic subjects. The hyperinsulinism of patients with acromegaly cannot be attributed to excess secretion of insulin.

In vitro determination of brain glucose metabolism in the temporal cortex from patients with Alzheimer's disease showed a marked decrease when compared with nondemented, age-matched control subjects. Additional determinations on normal human temporal cortex obtained at autopsy demonstrated an age-dependent decline in the rate of glucose use. These data provide an in vitro correlate for positron emission tomography studies that suggest decreased brain glucose use in Alzheimer's disease.

Aluminum accumulation has been implicated in the development of Alzheimer's Disease, a hallmark of which is decreased brain glucose metabolism. Dietary sources of aluminum include that which comes from the contact of food with aluminum cook ware, containers, foil, and utensils. Normal aluminum intake from all sources is estimated as 12-14 mg per day. We have evaluated brain glucose metabolism in the presence of physiologically achievable levels of aluminum, in the range 10(-15) to 10(-5) M. Our results indicate no effect of aluminum in the range tested. Thus the contact of food with aluminum cooking utensils cannot alone raise plasma aluminum concentrations to the millimolar levels required to decrease brain glucose metabolism. Non dietary pathophysiological mechanisms are operating which lead to the accumulation of tissue aluminum, since most of dietary aluminum is excreted by the kidney.

The ability of cimetidine to reduce the activity of hepatic aminolevulinic acid synthase (ALA-S) was examined in allylisopropyl acetamide (AIA) treated porphyric adult rats. A dose of 20 mg cimetidine/100 gm body weight resulted in a 50% decrease in the AIA-induced hepatic ALA-S activity compared to rats treated with AIA alone. Heme oxygenase activity was decreased 25% compared to rats treated with AIA alone. The effects of AIA and cimetidine on cytochrome P-450 were not additive, suggesting competition for a common site of interaction. The results suggest that cimetidine may prove to be useful in treating porphyria in humans.

Mitochondria isolated from the livers of old rats (26-30 months) were found to incorporate 41% less leucine into mitochondrial proteins as compared to those from young rats (2-3 months). The initial rates of incorporation of label were 145 cpm/mg/min for the "old" animals, and 320 cpm/mg/min for the young animal. No difference in either amino acid pool size or leakage of label through the mitochondrial membrane was detected in the two age groups. Young rats were treated in vivo with cycloheximide (10 mg/kg) followed by isolation and incubation of their mitochondria in vitro two hours later. There was a two-fold increase in incorporation of leucine into mitochondrial proteins. In contrast, mitochondria isolated from old rats showed a markedly blunted response to cycloheximide pre-treatment. When mitochondria isolated from young and old rats were exposed to inhibitors of mitochondrial protein synthesis, alpha-alpha-dipyridyl (2 x 10(-4)M) and ethanol (0.15M), the old mitochondria showed greater susceptibility to inhibition. These results suggest that the control of the biosynthesis of mitochondrial proteins is altered in the old animals.

There is currently a controversy of whether elderly people (over age 65) have an age-related physiologic decline in red cell parameters. If this is so, a new normal range might be established for geriatric patients, as has been suggested by others. However, since anemia is often the first sign of severe illness in a patient, new normal values might include a danger of overlooking patients with true anemia secondary to an underlying disease. In this article we shall review what is known about red cell parameters in elderly patients and attempt to answer the questions of whether new geriatric norms should be established.

Microvessels isolated from temporal cortex of patients with Alzheimer's disease showed decreased uptake of glucose when compared with vessels from age-matched or young control subjects. This was due to decreased hexokinase activity in the Alzheimer samples, as determined by ion exchange chromatography. This finding was confirmed independently by determination of the phosphorylation constant for hexokinase, K3, using positron emission tomography. The results suggest that Alzheimer's disease may result from a global defect in brain energy metabolism.

Isolated mitochondria from rat livers of various ages show a gradual decline in the rate of inner membrane-matrix protein synthesis with advancing age of the animal. Rats at 112-120 weeks synthesize these proteins at only 40% of the rate of 2-8-week-old animals. The initial rates of incorporation of label were 145 cpm/mg/minute for the "old" animals, and 320 cpm/mg/minute for the "young" animal. No difference in either amino acid pool size or leakage of label through the mitochondrial membrane was detected in the two age groups. Treatment of the mitochondria with ferrous ammonium sulphate produced a 1.62 fold increase in mitochondrial protein synthesis in the young animal but not in the old. Hemin treatment produced a similar effect. These results suggest that the decrease in delta-aminolevulinic acid synthase activity seen with age (Paterniti et al., 1978) may be due to a decrease in the synthesis of mitochondrial inner membrane proteins.

The binding of 125I-labeled porcine von Willebrand factor to washed human platelets was examined. In the absence of ristocetin, binding was found to be rapid, specific and saturable and was decreased in the presence of urea or at high ionic strength. Platelets were found to contain approx. 4760 binding sites for porcine von Willebrand factor with an average binding constant of 2.92 x 10(-7) M assuming the von Willebrand factor to be a tetramer with a molecular weight of 9 x 10(5). Although ristocetin was not absolutely required for binding, in its presence binding was increased.

Folate levels of serum and red blood cells (RBC) and vitamin B12 serum levels were investigated in 326 urban chronically ill elderly ambulatory patients and 41 healthy young control subjects. Two laboratory methods were used for investigating the folate levels, the microbiologic assay (MBA) with Lactobacillus casei and radioassay (RA). Serum and RBC samples of 326 patients were tested by the folate MBA and 270 of the same samples by the RIA methods. In the MBA 6.8% of the patients and 12.2% of controls had low levels of folate RBC (less than 200 ng/mL) and 1.8% of patients and 4.8% of controls had low serum folate levels (less than 5 ng/mL). All of the patients with the low folate levels had normal hematologic findings and no clinical symptoms of folate deficiency. In the RIA method, all of the patients and almost all of the control subjects (except one) had normal folate levels. Ten of the patients (3%) had low levels of serum vitamin B12 (less than 200 pg/mL). They were hematologically normal. They had normal Schilling tests and normal vitamin B12 dietary intake. Their RBC folate levels were normal and even somewhat higher. Forty percent of these patients had macular degeneration of the eyes. The data indicate the superiority of the RA method over the MBA and bring into question the accuracy of previous studies. The data furnish further evidence that a low vitamin B12 level in the elderly is not necessarily a true vitamin B12 deficiency and raise the possibility of an association between low B12 serum levels and macular degeneration of the eyes.

When iron deficiency occurs in the elderly, it is usually due to bleeding and not to nutritional lack or malabsorption. Iron deficiency early in life may lead to irreversible changes (for example, gastric achlorhydria) that are troublesome in later life. The nonhematologic effects of iron deficiency still need to be studied in the elderly. In particular, the role of iron in brain metabolism would seem important in geriatrics. Although it is important to prevent iron deficiency, indiscriminate use of iron could conceivably lead to iron overload. As with many beneficial compounds, patients must be cautioned against the prolonged ingestion of large amounts of iron salts.

Cimetidine is a well known inhibitor of the heme-containing enzyme cytochrome P-450. We have found that it also inhibits delta-aminolevulinic acid synthase (ALA-S) and microsomal heme oxygenase, the rate-limiting enzymes for heme synthesis and heme degradation respectively. Cytochrome P-450 content was decreased but microsomal heme concentration remained unaltered for a period of 30 min after in vivo cimetidine administration to rats. In vitro incubation of cimetidine with each of the above enzymes revealed no direct effect of cimetidine on ALA-S but about 50% inhibition of heme oxygenase and 20% reduction in cytochrome P-450 content. This suggests that a metabolite of cimetidine inhibits ALA-S activity in vivo, while the drug itself or a metabolite inhibits heme oxygenase both in vivo and in vitro. A rise in ALA-S activity seen after its early inhibition and its return to approximate control values after 60 min suggest a reversible inhibition of ALA-S by a metabolite of cimetidine and may correspond to its clearance from the animal. An elevation in microsomal heme content paralleled the rise in ALA-S activity while microsomal heme oxygenase activity returned to only 65% of control value 60 min after cimetidine treatment. Cytochrome P-450 content did not change after its initial decrease, suggesting that irreversible alteration had occurred.

Porcine platelet aggregating factor was purified from porcine plasma by a rapid batch procedure which included polyethylene glycol precipitation and adsorption on calcium citrate. The aggregating factor was separated from antihemophilic factor by gel chromatography in the presence of 1 M MgCl2. It appeared homogenous when examined by immuno- or SDS-gel electrophoresis. The molecular weight was estimated to be 10 million by exclusion chromatography. After reduction, subunit molecular weight, by sodium dodecyl sulfate (SDS)-gel electrophoresis, was 225 000. Amino acid and carbohydrate composition were similar to those reported for the bovine material. The porcine platelet aggregating factor was found to have no free sulfhydryl groups or exposed disulfide bonds. Binding of formalin-fixed washed human platelets to the aggregating factor linked to Sepharose was inhibited in 0.5 M NaCl or 2.7 M urea and reversed by the presence of free aggregating factor in a concentration-dependent manner. Ristocetin had little or no discernible effect on binding.

Riege and Metter provide a useful review of the application of PET in the evaluation of Alzheimer's disease (AD). We share their enthusiasm for continued support and development of tools to image metabolic processes. Our commentary focuses on neuroimaging and the diagnosis of AD and introduces some new data that directly impacts on the interpretation of PET-2-deoxyglucose (2DG) data.

Isolated rat liver mitochondrial protein synthesis was severly inhibited by alpha, alpha-dipyridyl (a ferrous iron-chelating agent), chloramphenicol and hemin (10(-7) M or greater). In contrast, gamma, gamma-dipyridyl (a non-iron-chelating analogue of alpha, alpha-dipyridyl), cycloheximide and lower concentrations of hemin were non-inhibitory. The inhibitory action of alpha, alpha-dipyridyl was reversed by addition of Fe(NH4)2(SO4)2 while ZnCl2, CuCl2 and CoCl2 were ineffective. Hemin, however, did not protect against the alpha, alpha-dipyridyl inhibition of mitochondrial protein synthesis. These results indicate that ferrous iron is required for mitochondrial protein synthesis and suggests that it is through a mechanism independent of hemin concentration.

Serum Vitamin B12 levels were determined on 378 patients ranging in age from 56 to 104 years with a median age of 77 for both males and females. A radiodilution method was employed for these determinations. This screening procedure identified 26 patients with low serum B12 levels. Nineteen of these patients had no other symptoms and were hematologically normal. The B12 binding proteins, transcobalamins (TC) I, II, and III were quantitated employing QUSO and DEAE cellulose batch separations. The total number of TC II binding/affinity sites for B12 were elevated in both the normal and low B12 elderly groups. About 17% of the total serum B12 was carried by TC II in the control group while only 4% of the total was carried on TC II in both the normal and low B12 elderly. This was accompanied by an increase in unsaturation in TC II for these two groups. The findings suggest that an alteration in the TC II-B12 delivery system has occurred in the elderly.